Assessment of antibacterial potentials of Garcinia Kola seed extracts and their interactions with antibiotics
- Authors: Sibanda, Thulani
- Date: 2007
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11242 , http://hdl.handle.net/10353/71 , Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants
- Description: The antibacterial potency of the extracts of the seed of Garcinia kola (bitter kola) was investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The killing rates of the active extract as well as their potential for combination antibacterial therapy with standard antibiotics were also elucidated using standard procedures. The aqueous and acetone extracts of the seed were screened for activity against 27 bacterial isolates. The aqueous extract exhibited activity mainly against Gram positive organisms with Minimum inhibitory concentration (MIC) values ranging from 5 mgml-1 – 20 mgml-1, while the acetone extract showed activity against both Gram negative and Gram positive organisms with MIC values ranging from 10 mgml-1 - 0.156 mgml-1. The acetone extract also showed rapid bactericidal activity against Staphylococcus aureus ATCC 6538 with a 3.097 Log10 reduction in counts within 4 hours at 0.3125 mgml-1 and a 1.582 Log10 reduction against Proteus vulgaris CSIR 0030 at 5 mgml-1 after 1 hour. In addition, the aqueous, methanol and acetone extracts of the seeds also exhibited activity against four clinical strains of Staphylococcus isolated from wound sepsis specimens. The MIC values for the aqueous extract were 10 mgml-1 for all the isolates while the acetone and methanol extracts had lower values ranging from 0.3125 - 0.625 mgml-1. The acetone extract was strongly bactericidal against Staphylococcus aureus OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 within 4 hours of exposure and a complete elimination of the organism after 8 hours. The bactericidal vi activity of the same extract against Staphylococcus aureus OKOH1 was weak, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4× MIC) in 24 hours. In the test for interactions between the acetone extract of the seeds and antibiotics, synergistic interactions were observed largely against Gram positive organisms using the FIC indices, (indices of 0.52 - 0.875) with combinations against Gram negatives yielding largely antagonistic interactions (indices of 2.0 to 5.0). Synergy (≥ 1000 times or ≥ 3 Log10 potentiation of the bactericidal activity) against both Gram negative and Gram positive organisms was detected by time kill assays mainly involving the antibiotics tetracycline, chloramphenicol, amoxycillin and penicillin G. Combinations involving erythromycin and ciprofloxacin consistently gave antagonistic or indifferent interactions. We conclude that the acetone extract of Garcinia kola seeds possess strong bactericidal activities against both Gram positive and Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections including the problematic staphylococcal wound infections. In addition, the acetone extract can be a potential source of broad spectrum resistance modifying compounds that can potentially improve the performance of antibiotics in the treatment of drug resistant infections.
- Full Text:
- Date Issued: 2007
Antibacterial properties of the methanol extract of helichrysum pedunculatum
- Authors: Ncube, Nqobile S
- Date: 2008
- Subjects: Medicinal plants , Methanol , Helichrysum
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11241 , http://hdl.handle.net/10353/461 , Medicinal plants , Methanol , Helichrysum
- Description: The methanol extract of Helichrisum pedunculatum was screened for antimicrobial activity up to a concentration of 5 mg/ml using the agar dilution technique. A number of test bacterial isolates, comprising both Gram negative and Gram positive organisms were susceptible to the crude extract of the plant. The minimum inhibitory concentrations (MICs) of the extract ranged between 1 and 5 mg/ml for the susceptible organisms. The MICs of the selected antibiotics, chloramphenicol and penicillin, ranged between 2 and 4 mg/L, and 2 and 32 mg/L respectively against Bacillus cereus, Proteus vulgaris and Staphylococcus aureus OKOH1. Bactericidal activity was determined by the time kill assay. The methanol extract of the plant was not bactericidal at 1 × MIC for B. cereus, P. vulgaris and Staph. aureus OKOH1. At 2 × MIC the extract was bacteriostatic against B. cereus but bactericidal against P. vulgaris and Staph. aureus OKOH1. Combination studies were done at 1/2 × MIC, 1 × MIC and 2 × MIC of the plant extract with 1 × MIC of the antibiotics. Combinations of the plant extract and chloramphenicol resulted in mostly indifferent interactions against P. vulgaris and Staph. aureus OKOH1 but synergistic interactions at higher concentration of the plant extract for B. cereus. Penicillin combinations gave synergistic interactions at lower concentrations of the plant for P.vulgaris and Staph. aureus OKOH1 but was mostly indifferent for B. cereus.
- Full Text:
- Date Issued: 2008
Biodiversity of Salmonella strains isolated from selected water sources and wastewater discharge points in the Easern Cape Province of South Africa
- Authors: Mafu, Nwabisa Charity
- Date: 2008
- Subjects: Biodiversity conservation -- South Africa -- Eastern Cape , Biodiversity -- South Africa -- Eastern Cape , Salmonella typhimurium
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11248 , http://hdl.handle.net/10353/74 , Biodiversity conservation -- South Africa -- Eastern Cape , Biodiversity -- South Africa -- Eastern Cape , Salmonella typhimurium
- Description: In this study, the diversity of forty Salmonella isolates from selected drinking water and wastewater sources in the Eastern Cape Province of South Africa was assessed using parameters such as protein and lipopolysaccharide profile analysis, DNA fingerprinting and antibiotic susceptibility profile as test indices. Wastewater samples from Amalinda, Shornville and Fort Hare wastewater plants, and water samples from Gogogo and Tyume rivers were collected on ice and transported to the laboratory of the department of Microbiology and Biochemistry, University of Fort Hare for processing. The DNA dendograms of Salmonella and the applied UPGMA revealed 4 similarity groups of the strains. Most of the strains recovered from Amalinda, Shornville, Fort Hare wastewater plants, Gogogo and Tyume rivers show a high percentage of genetic similarity. On the other hand, protein dendograms of Salmonella isolates revealed 2 similarity groups which varied widely. Also, the lipopolysaccharide dendograms revealed three similarity groups with the first similarity groups showing a very high relatedness between strains from different water sources. The second similarity group included 16 strains which formed a rather homogenous group, and the third similarity group formed a distinct group. Of the seven antibiotics and sulfonamides tested against the Salmonella species, five namely, neomycin, chloramphenicol, kanamycin, streptomycin and cotrimoxazole were significantly inhibitory, while the bacteria showed considerable resistance to doxycycline and sulphamethoxazole. Our results based on restriction digestion, SDS/PAGE and dendogram construction show that there is a high similarity between the forty Salmonella strains studied, and that these methods are valuable tools for evaluating the relatedness ofSalmonella species. Our observations have proffered a veritable reference point on the diversity of Salmonella strains in the studied area.
- Full Text:
- Date Issued: 2008
Parasite prevalence, nutritionally-related blood metabolites and pre-slaughter stress response in Nguni, Bonsmara and Angus steers raised on veld
- Authors: Ndlovu, Thulile
- Date: 2008
- Subjects: Parasites , Nguni cattle , Bonsmara cattle , Metabolites , Slaughtering and slaughter-houses , Aberdeen -- Angus cattle
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11258 , http://hdl.handle.net/10353/73 , Parasites , Nguni cattle , Bonsmara cattle , Metabolites , Slaughtering and slaughter-houses , Aberdeen -- Angus cattle
- Description: The effects of month on body weight, body condition scores, internal parasite prevalence and on nutritionally related blood metabolites were studied in Angus, Bonsmara and Nguni steers raised on sweet veld. Pre-slaughter stress was also determined using catecholamines, cortisol, dopamine, packed cell volume and serum creatinine levels. The blood chemical constituents evaluated included glucose, cholesterol, total protein, creatinine, urea, globulin, albumin, calcium, phosphorus, magnesium, aspartate amino transferase (AST), alkaline phosphatase (ALP) and creatinine kinase (CK). The Nguni steers maintained their body condition throughout the study period whereas Angus steers had the least body condition scores. Parasite levels were high during the rainy season and low during the dry season. The predominant internal parasites were Haemonchus (39.3 percent), Trichostrongylus (37.8 percent), Cooperia pectinita (25.5 percent), Fasciola gigantica (16.3 percent) and Ostertagia ostertagi (11.2 percent). The Nguni had the least parasite infestation levels and had high PCV levels. Nguni had higher levels of cholesterol and glucose (2.86 and 4mmol/l, respectively) than the other two breeds. Nguni and Bonsmara steers had higher (P<0.05) mineral levels. There were significant breed and month differences for glucose, cholesterol, creatinine, calcium, albumin, phosphorus, albumin-globulin ratio and ALP levels. Bonsmara was more susceptible to transport and pre-slaughter stress as it had the highest (P<0.05) levels of adrenalin (10.8nmol/mol), noradrenalin (9.7nmol/mol) and dopamine (14.8nmol/mol) levels, whereas the Nguni had the least levels of adrenalin (6.5nmol/mol), noradrenalin (4.6nmol/mol) and dopamine (4nmol/mol) levels. In conclusion, Nguni steers were better adapted to the local environmental conditions
- Full Text:
- Date Issued: 2008
Assessment of antibiotic production by some marine Streptomyces isolated from the Nahoon Beach
- Authors: Ogunmwonyi, Isoken Nekpen Henrietta
- Date: 2010
- Subjects: Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11243 , http://hdl.handle.net/10353/264 , Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Description: Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease.
- Full Text:
- Date Issued: 2010
Assessment of bioflocculant production by some marine bacteria isolated from the bottom sediment of Algoa Bay
- Authors: Cosa, Sekelwa
- Date: 2010
- Subjects: Flocculants , Bacteria -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11244 , http://hdl.handle.net/10353/404 , Flocculants , Bacteria -- South Africa -- Algoa Bay
- Description: Several problems concerning the use of conventional synthetic flocculants has necessitated the need for alternative cost effective, safe and efficient bioflocculants from microorganisms inhabiting many environments, particularly those from unusual environments. Hence, this study assessed bioflocculant production by three marine bacteria isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa. Analysis of the 16S rDNA sequences led to their identification as Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky. Several factors affecting the production and activity of the bioflocculant(s) were studied. Halobacillus sp. Mvuyo produced bioflocculant optimally with glucose (76%) and ammonium chloride (93%) as sole carbon and nitrogen sources, respectively and at neutral pH and in the presence of Ca2+. On the other hand, Virgibacillus sp. Rob preferred glucose (70.4 %) and iron sulphate (74%) as carbon and nitrogen source respectively; an alkaline pH (12.0) and Fe2+. Oceanobacillus sp. Pinky produced bioflocculant optimally when sucrose (80%) and peptone (72.4 %) were used as carbon and nitrogen source respectively, at neutral pH, and in the presence of Ca2+ cation. The chemical analyses of the partially purified bioflocculants revealed that the bioflocculants produced by Halobacillus sp. Mvuyo and Oceanobacillus sp. Pinky were glycoproteins, while that produced by Virgibacillus sp. Rob was a polysaccharide. We thus conclude that Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky hold promise as producers of new and efficient bioflocculant(s). We recommended development of process conditions for large scale production of the bioflocculants followed by their detailed characterization, as well as pilot scale assessment of the applicability of the purified bioflocculant in water/wastewater treatment and other industrial uses
- Full Text:
- Date Issued: 2010
In vitro bioactivity of crude extracts of Lippia javanica on clinical isolates of Helicobacter pylori: preliminary phytochemical screening
- Authors: Nkomo, Lindelwa Precious
- Date: 2010
- Subjects: Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11257 , http://hdl.handle.net/10353/508 , Extracts , Helicobacter pylori , Antibiotics , Drug resistance in microorganisms , Materia medica, Vegetable
- Description: Helicobacter pylori classified as a class 1 carcinogen is a common human pathogen implicated in certain gastrointestinal diseases. Helicobacter pylori infection is acquired mainly in childhood, especially in developing countries. H. pylori infection causes peptic ulcer, duodenitis, gastritis and cancer. The growing resistance of H. pylori to antibiotics used in its treatment as well as other innate limitations of the triple therapy has necessitated a search for alternative treatment from natural sources which could be readily available, less cost effective. The antimicrobial activity of solvents (acetone, ethanol, methanol, chloroform and water) crude extracts of Lippia javanica were investigated against 31 H. pylori strains by the agar well diffusion technique. The minimum inhibitory concentration (MIC) was determined by spectrophotometric analysis at 620 nm using the broth micro dilution method and the rate of kill by broth dilution method. Phytochemical analysis was also performed. H. pylori standard strain NCTC 11638 was included as a positive control. Metronidazole and amoxicillin were used as positive control antibiotics. The ANOVA test was used to analyze the results using SPSS version 17.0. The strains were inhibited by all the extracts with inhibition zones of diameter ranging from 0-36 mm and 0-35 mm for the control antibiotic, clarithromycin. The MIC90 ranged from 0.039- 0.625 mg/mL for acetone; 0.039-1.25mg/mL for methanol, 0.00195-0.313 mg/mL for ethanol; 0.01975-2.5 mg/mL for metronidazole and 0.0048-2.5 mg/mL for amoxicillin. Acetone extract completely inhibited strain PE369C at MIC (0.1 mg/mL) and 2× MIC (0.2 mg/mL) in 18h and at ½× MIC (0.05 mg/mL) in 36h. Strain PE466C was completely inhibited at 4× MIC in 72h. Phytochemical analysis revealed the presence of flavonoids, saponins, tannins, steroids and alkaloids. The results indicate that the extracts of the leaves of L. javanica may contain compounds with anti-H. pylori activity and merits further study to identify the compounds.
- Full Text:
- Date Issued: 2010
Prevalence and risk factors for Helicobacter pylori transmission in the Eastern Cape Province application of immunological molecular and demographic methods
- Authors: Dube, Callote
- Date: 2010
- Subjects: Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11262 , http://hdl.handle.net/10353/265 , Helicobacter pylori , Bacterial diseases , Gastritis -- Risk factors , Bacterial diseases -- Risk factors , Gram-negative bacteria , Gram-negative bacterial infections , Helicobacter , Helicobacter infections , Helicobacter pylori -- South Africa -- Eastern Cape
- Description: Helicobacter pylori (H. pylori) is a microaerophilic, Gram-negative motile curved rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the organism potentially induces chronic gastritis and peptic ulcer disease. In addition, H. pylori plays a role in the etiology of gastric cancer and gastric MALT lymphoma. The risk of infection is increased in those living in the developing world, which has been ascribed to precarious hygiene standards, crowded households, and deficient sanitation common in this part of the world. Thus, the aim of this study was to identify the risk factors in the transmission of H. pylori in our environment, i.e. in Nkonkobe Municipality in the Eastern Cape Province, South Africa. Faecal samples were collected from 356 apparently healthy subjects, consisting of 168 males and 188 females aged from 3 months to 60 years (Mean = 31 years). A standardized questionnaire was applied, it described demographic characteristics including age, sex, household hygiene, socioeconomic status, area of residence, duration of stay in the area, sharing bath water, sharing tooth brush, habit of sucking thumb, medication currently being taken or medication taken within the past three months, source of water, type of toilet used, education and occupation. A sandwich-type enzyme immunoassay amplification technology (Amplified IDEIA TM Hp StAR TM , Oxoid, UK) was used to analyze the faecal samples for the detection of H. pylori antigens using monoclonal antibodies specific for H. pylori antigens. To assess the possibility of faecal oral route with tap water as an intermediary link, PCR targeting the ureC (glmM), a highly conserved gene in H. pylori ii was carried out to detect H. pylori DNA in faecal samples of already positive samples by HpSA test as well as in direct tap water used by the H. pylori positive subjects. QIAamp DNA stool mini kit was used to extract DNA from faecal samples. Tap water samples were then obtained using sterile bottles from areas inhabited by H. pylori positive subjects as determined by HpSA test and PCR. DNA extraction from water samples was done using UltraCleanTM Water DNA Isolation Kit (0.22μm) according to the manufacturer’s instructions. PCR with primers specific for H. pylori glmM gene was carried out with both positive and negative controls incorporated. Fisher’s exact test was used to assess the univariate association between H. pylori infection and the possible risk factors. Odds ratio (OR) and the corresponding 95 percent confidence interval (CI) were calculated to measure the strength of association using EPI INFO 3.41 package. P values of < .05 were required for significance. The precision rate of the diagnostic tests used was also determined. H. pylori antigen was detected in 316 of the 356 subjects giving an overall prevalence of 88.8 percent. Prevalence increased with age from 75.9 percent in children < 12 years age to 100 percent in the age group from 13 years to 24 years, also 100 percent prevalence of H. pylori was recorded in young adults aged 25-47 years and subjects aged 60 years (P < .05). H. pylori prevalence was higher in females than in males. Of 188 females who participated in the study, H. pylori antigen was detected in 172 (91.5 percent) versus 144 (85.7 percent) of 168 males (P > .05). Interestingly, H pylori antigen was detected more often (100 percent) in the high socioeconomic group than in those of low socioeconomic group (85.9 percent). Sixteen (66.7 percent) of twenty four faecal samples that had previously tested positive for the organism by HpSA test were confirmed positive by PCR. However none of the treated tap water samples tested positive for the organism by PCR. The present iii study revealed a high prevalence of H. pylori in faecal samples of asymptomatic individuals in the Nkonkobe Municipality, an indication of active infection. The obtained results also revealed that direct treated tap water might not be playing a crucial role in the oral transmission of H. pylori in the studied population.
- Full Text:
- Date Issued: 2010
Assessment of the antibacterial properties of n-Hexane extract of Cocos Nucifera and its interactions with some conventional antibiotics
- Authors: Akinyele, Taiwo Adesola
- Date: 2011
- Subjects: Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11245 , http://hdl.handle.net/10353/416 , Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Description: Cocos nucifera belong to the family Aracaceae (palm Family). The English name is coconut and it is used extensively as medicinal remedies against infections such as urinary tract infections, gastro intestinal infections, skin and wound infections. The in vitro antibacterial (including anti-listerial and anti-vibrio) properties as well as the evaluation of the combination potentials of the plant extract with six front-line antibiotics were evaluated in this study using standard procedures. The in vitro anti-listerial properties of the crude aqueous and n-Hexane extract of the husk of Cocos nucifera were carried out against 37 Listeria isolates. Twenty-nine of the test organisms were susceptible to the aqueous extract while thirty were susceptible to the n-Hexane extract both at the screening concentration of 25 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.6 - 5.0 mg/ml. For the aqueous extract, average log reduction in viable cell count ranged between 0.32 Log10 and 4.8 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 2.4 Log10 and 6.2 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. The time-kill characteristics of the two extracts suggest that at higher concentration (2 × MIC) and longer duration of interaction (8 hr), more bacteria were killed. In vitro anti-vibrio and antibacterial properties experiment revealed that of all the 45 vibrio and 25 bacteria strains that was tested, 37 were susceptible to the aqueous extract and 38 to the n-Hexane extract, while 17 were susceptible to the aqueous extract and 21 to the n-Hexane extract. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.3 - 5.0 mg/ml. viii The time kill studies revealed that for the aqueous extract, average log reduction in viable cell count in time kill assay ranged between 0.12 Log10 and 4.2 Log10 CFU/ml after 8 hr interaction at 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 0.56 Log10 and 6.4 Log10 CFU/ml after 8 hr interaction in 1 × MIC and 2 × MIC. In the test for the combination interactions, the checkerboard method revealed synergy of 67% and indifferent of 33%, while the time kill assay detected synergy in 72% and indifferent in 28% of the combinations tested. The synergy detected was not specific to any of the antibiotics or the Gram reaction of the bacteria, and no antagonism was detected. We conclude that the aqueous and n-Hexane extract of the husk of C. nucifera contains potential broad spectrum antibiotics resistance modulating compounds that could be relevant in the treatment of infections caused by these pathogens. In addition, the husk which is being discarded as agro waste will opens up a vista of opportunities for utilization for therapeutic purposes
- Full Text:
- Date Issued: 2011
Bioactivity and phytochemical analysis of Hydnora Africana on some selected bacterial pathogens
- Authors: Nethathe, Bono Bianca
- Date: 2011
- Subjects: Helicobacter pylori , Medicinal plants -- South Africa -- Eastern Cape , Microbial sensitivity tests , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Plants -- Analysis , Staphylococcus aureus , Aeromonas hydrophila , Drug resistance in microorganisms , Plant-pathogen relationships
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11247 , http://hdl.handle.net/10353/d1001063 , Helicobacter pylori , Medicinal plants -- South Africa -- Eastern Cape , Microbial sensitivity tests , Herbs -- Therapeutic use -- South Africa -- Eastern Cape , Plants -- Analysis , Staphylococcus aureus , Aeromonas hydrophila , Drug resistance in microorganisms , Plant-pathogen relationships
- Description: Abstract Medicinal plants have been for long remedies for human diseases because they contain components of therapeutic value. The growing problem of antibiotic resistance by organisms demands the search for novel compounds from plant based sources. The present study was aimed at evaluating the bioactivity and phytochemical analysis of Hydnora africana on clinical and standard strains of Helicobacter pylori (PE 252C and ATCC 43526), Aeromonas hydrophila ATCC 35654, and Staphylococcus aureus NCT 6571 in an effort to identify potential sources of cheap starting materials for the synthesis of new drugs against these strains. Ethyl acetate, acetone, ethanol, methanol, and water crude extracts of H. africana were screened for activity against the test organisms using the agar well diffusion assay. The Minimum Inhibitory Concentration (MIC50) and Minimum Bactericidal Concentration (MBC) of the most potent extracts were determined by the microdilution method, followed by qualitative phytochemical analysis. Results were analyzed statistically by ANOVA one - way test. Different concentrations (200,100, 50mg/mL) of the methanol, acetone, ethanol and ethyl acetate extracts showed activity against S. aureus and A. hydrophila while for H. pylori, only methanol and ethyl acetate extracts were active; water showed no activity for all studied bacterial pathogens. Mean zone diameter of inhibition which ranged from 0-22mm were observed for all test bacterial pathogens and 14-17mm for ciprofloxacin. The activity of methanol and ethyl acetate extracts were statistically significant (P< 0.05) compared to all the other extracts. MIC50 and MBC ranged from 0.078 – 2.5mg/mL, 0.78-25mg/mL respectively for all tested bacterial pathogens. For ciprofloxacin, the MIC50 and MBC ranged from 0.00976 – 0.078mg/mL and 0.098– 0.78mg/mL respectively. There was no statistically significant difference between extracts (methanol, acetone, ethanol, ethyl acetate) and the control antibiotic (ciprofloxacin) (P> 0.05). Qualitative phytochemical analysis confirmed the presence of alkaloids, saponins, steroids, tannins and flavonoids in the methanol, acetone,ethanol and ethyl acetate extracts. The results demonstrate that H. africana may contain compounds with therapeutic potentials which can be lead molecules for semi-synthesis of new drugs.
- Full Text:
- Date Issued: 2011
Effects of genetically modified maize (MON810) and its residues on the functional diversity of microorganisms in two South African soils
- Authors: Puta, Usanda
- Date: 2011
- Subjects: Genetically modified foods -- South Africa , Transgenic plants -- South Africa , Crops -- Genetic engineering -- South Africa , Soil microbiology -- South Africa , Microorganisms , Microbial ecology , Rhizosphere -- Microbiology , Vesicular-arbuscular mycorrhizas , Corn -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11250 , http://hdl.handle.net/10353/419 , Genetically modified foods -- South Africa , Transgenic plants -- South Africa , Crops -- Genetic engineering -- South Africa , Soil microbiology -- South Africa , Microorganisms , Microbial ecology , Rhizosphere -- Microbiology , Vesicular-arbuscular mycorrhizas , Corn -- South Africa
- Description: Genetically modified (GM) crops are commercially cultivated worldwide but there are concerns on their possible negative impacts on soil biodiversity. A glasshouse study was conducted to determine effects of Bt maize residues on soil microbial diversity. Residues of Bt maize (PAN 6Q-308B) and non-Bt maize (PAN 6Q-121) were incorporated into the soil and corresponding maize seeds planted. The treatments were replicated three times. Fertilizer and water application were similar for both treatments. Rhizosphere and bulk soil was destructively sampled from each treatment and analyzed for microbial community level physiological profiles using Biolog plates with 31 different carbon substrates. Absorbance in the Biolog plates was recorded after 72 h of incubation at 20oC. Arbuscular mycorrhizal fungi spore counts were also determined. Field studies were conducted at the University of Free State and University of Fort Hare Research Farms to determine the effects of growing Bt maize on soil microbial diversity. One Bt maize cultivar (PAN6Q-308B) and non-Bt maize (PAN6Q-121) were grown in a paired experiment at University of Free State farm, while two Bt maize (DKC61-25B and PAN6Q-321B) and their near-isogenic non-Bt maize lines (DKC61-24 and PAN6777) were grown in a randomized complete block design with three replicates. Fertilization, weed control and water application, were similar for both Bt maize cultivars and their non-Bt maize counterparts. Rhizosphere soil samples were collected by uprooting whole plants and collecting the soil attached to the roots. The samples were analysed for microbial diversity and for arbuscular mycorrhizae fungal spore counts. Principal component analysis showed that soil microbial diversity was affected more by sampling time whereas genetic modification had minimal effects. Presence of residues also increased the diversity of microorganisms. Mycorrhizal fungal spores were not affected by the presence of Bt maize residues. Growing Bt maize had no effect on the soil microbial diversity in the rhizosphere.
- Full Text:
- Date Issued: 2011
In vitro activity of bioactive compounds of selected South African medicinal plants on clinical isolates of Helicobacter pylori
- Authors: Okeleye, Benjamin Ifeoluwa
- Date: 2011
- Subjects: Helicobacter pylori , Microbial sensitivity tests , Traditional medicine -- South Africa , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11255 , http://hdl.handle.net/10353/310 , Helicobacter pylori , Microbial sensitivity tests , Traditional medicine -- South Africa , Gram-negative bacterial infections
- Description: The stem bark of Peltophorum africanum and Bridelia micrantha are used in South Africa traditional medicine for treatment of intestinal parasites, relieve problems and human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS). The growing problem of antibiotic resistance by Helicobacter pylori the major etiological agent in gastritis, gastric cancer, peptic and gastric ulcer demands the search for novel compounds from plant based sources. This study was aimed to determine the antimicrobial activity of five solvent (ethylacetate, acetone, ethanol, methanol and water) extracts of the stem bark of P. africanum and B. micrantha on clinical strains of H. pylori in a bid to identify potential sources of cheap starting materials for the synthesis of new drugs. H. pylori strains were isolated from patients presenting with gastric related morbidities at the Livingstone Hospital, Port Elizabeth for endoscopy and confirmed following standard microbiology procedures. The plant extracts including clarithromycin were tested against 31 clinical strains of H. pylori by the agar well diffusion method. The most potent extract was evaluated by the microdilution method to determine the Minimum Inhibitory Concentration (MIC50&90), followed by the rate of kill. Preliminary phytochemical analysis was carried out. The one way ANOVA test was used to statistically analyse the results. All the extracts demonstrated anti-H. pylori activity with zone diameters of inhibition that ranged from 0 to 23 mm for the extracts and 0 to 35 mm for clarithromycin. Marked susceptibility (100%) was recorded for the ethyl acetate extract of P. africanum (P. afr. EA) and the acetone extract of B. micrantha (B. mic. A), which were statistically significant (P < 0.05) compared to all other extracts and clarithromycin. For B. micrantha ethyl acetate extract, 93.5 percent susceptibility was observed while for the control iv antibiotic, clarithromycin it was 58.1 percent. The MIC50 ranged from 0.0048 to 0.313 mg/mL for P. afr. EA, and from 0.0048 to 0.156 mg/mL for B. mic. EA; MIC90 ranged from 0.156 mg/mL to 0.625 mg/mL and 0.0048 to 2.5 mg/mL for P. afr. EA and B. mic. EA respectively. There was a significant statistical difference observed in potency of both P. afr. EA and B. mic. A compared to the two antibiotics (P < 0.05). One hundred percent killing by P. afr EA was observed at 0.05 mg/mL (½ x MIC) and 0.2 mg/mL (2 x MIC) in 66 h for strain PE466C and PE252C respectively. For B. mic. EA, 100 percent killing effect of both strains (PE430C and PE369C) was observed at 0.1 mg/mL (2 x MIC) in 66 h. Qualitative phytochemical analysis confirmed the presence of alkaloids, flavonoids, steroids, tannins and saponins in the ethyl acetate extracts of both plants, which could be a potential template of lead molecule for the design of new anti- Helicobacter pylori therapies.
- Full Text:
- Date Issued: 2011
In-vitro anti-vibrio activities of crude extracts of Garcinia Kola seeds
- Authors: Penduka, Dambudzo
- Date: 2011
- Subjects: Microbial sensitivity tests , Drug resistance in microorganisms , Antibiotics , Garcinia , Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11256 , http://hdl.handle.net/10353/405 , Microbial sensitivity tests , Drug resistance in microorganisms , Antibiotics , Garcinia , Medicinal plants
- Description: The n-Hexane, dichloromethane, methanol and aqueous crude extracts of Garcinia kola (Heckel) seeds were screened for their anti-Vibrio activities against 50 Vibrio bacteria isolated from wastewater final effluents. The 50 isolates consisted of different Vibrio species namely V. fluvialis (14), V. vulnificus (12), V. parahaemolyticus (12), V. metschnikovii (3) and 9 others unidentified to the specie level. The n-Hexane, dichloromethane and methanol extracts had activities against 16 (32 percent) of the Vibrio isolates, while the aqueous extracts had activities against 12 (24 percent) all at a screening concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) were 0.313-0.625 mg/ml, 0.313-0.625 mg/ml, 0.313-2.5 mg/ml and 10 mg/ml for n-Hexane, dichloromethane, methanol and aqueous extracts respectively. Rate of kill studies were carried out against three different Vibrio species namely V. vulnificus (AL042), V. parahaemolyticus (AL049) and V. fluvialis ( AL040) using the n-Hexane, dichloromethane and methanol extracts at 1× to 4 × MICs and 2 hour exposure. About 96.3 percent, 82.2 percent, and 78.1 percent (V. fluvialis AL040); 92.6 percent, 87.8 percent and 68.9 percent (V. parahaemolyticus AL049); and 91.6 percent, 64.4 percent, 60 percent (V. vulnificus AL042) of the bacteria were killed by the crude n-Hexane, dichloromethane and methanol extracts respectively after 2 hour exposure time at 4× MIC. The patterns of activity were bacteriostatic, with the n-Hexane extracts being most effective in activity. We conclude that the Garcinia kola seeds have promise in the treatment and management of infections caused by Vibrio species.
- Full Text:
- Date Issued: 2011
Phytochemical analysis and bioactivity of the stem bark of Combretum Molle on some selected bacterial pathogens
- Authors: Nyenje, Mirriam, E
- Date: 2011
- Subjects: Drug resistance in microorganisms , Materia medica, Vegetable , Antibiotics , Microbial sensitivity tests , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11261 , http://hdl.handle.net/10353/391 , Drug resistance in microorganisms , Materia medica, Vegetable , Antibiotics , Microbial sensitivity tests , Gram-negative bacterial infections
- Description: Antimicrobial resistance is a worldwide problem that has deleterious long-term effects as the development of drug resistance outpaces the development of new drugs. Plants have been used for many generations for healing purposes, and screening of extracts of these plants has often yielded positive outcomes. This study was aimed at isolating and characterizing the major active antimicrobial compounds present in the stem bark of C. molle, in a bid to identify potential sources of cheap starting materials for the synthesis of new drugs. Various solvents (hexane, ethyl acetate, dichloromethane, acetone, ethanol and methanol) were used for extraction. The agar well diffusion technique was used to screen for antimicrobial activity of C. molle extracts against Streptococcus pyogenes ATCC 49399, Plesiomonas shigelloides ATCC 51903, Pseudomonas aeruginosa ATCC 15442, Helicobacter pylori ATCC 43526 and Helicobacter pylori 252C (clinical isolate); minimum inhibition concentration (MIC) of the most active extracts was determined by the broth dilution method. Fractionation of acetone extract was done by thin layer chromatography (TLC) and bioautography to determine the compounds present and their antimicrobial activity respectively. The acetone extract was purified by column chromatography and their MIC determined. The most potent fraction (EA4) was subjected to Gas chromatography- Mass spectrometry (GC-MS) and High performance liquid chromatography (HPLC) for identification of the active compounds. Results were analyzed by the Fisher‟s exact test. All the extracts tested demonstrated antimicrobial activity with zone diameters of inhibition ranging from 0–32 mm. Acetone was the most potent extract with its MIC ranging from 0.078–5.0 mg/mL. Seventeen fractions were collected from column chromatography and the most active fraction against all the organisms was EA 4 (eluted with 100 percent ethyl acetate), with its MIC ranging from 0.078 - 2.5mg/mL. There was no statistically significant difference (P>0.05) in the potency of the xii four extracts (acetone, methanol, ethanol and ethyl acetate) and antibiotic (ciprofloxacin) on the different bacterial strains tested, likewise the crude extract and the fractions. No compound was detected by GC-MS whereas numerous peaks were identified by HPLC implying that the active compounds in this plant are non volatile. We could not identify the compounds thereby proposing further studies using Nuclear magnetic resonance to identify the compounds. The study revealed that the acetone extract of C. molle was the most active against all the test organisms and therefore justifies the use of this plant in traditional medicine.
- Full Text:
- Date Issued: 2011
Comparative in-vitro activities of trimethoprimsulfamethoxazole and the new fluoroquinolones against confirmed extended spectrum beta-lactamase producing Stenotrophomonas maltophilia in Nkonkobe Municipality, Eastern Cape environment
- Authors: Adeyemi, Oluwatosin Oluwakemi
- Date: 2012
- Subjects: Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11275 , http://hdl.handle.net/10353/d1007576 , Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Description: Stenotrophomonas maltophilia is increasingly emerging as an opportunistic pathogen of global concern. Due to its inherent resistance to several classes of antibiotics including carbapenems and its ability to acquire mobile resistance elements, treatment of infections caused by S. maltophilia is a constant challenge for clinicians. Trimethoprim-sulphamethoxazole (TMP-SMX) is the generally accepted antibiotic of choice for the treatment of infections caused by this organism, but resistance to the drug is increasingly being reported; hence, the need for alternative therapeutic options. In this study, the antimicrobial susceptibility profile of 110 commensal S. maltophilia isolates obtained from Nkonkobe municipality, Eastern Cape Province, Republic of South Africa was investigated. Twenty-one antibiotics including TMP-SMX and the newer fluoroquinolones; levofloxacin, gatifloxacin and moxifloxacin were included in the antibiotic panel. About 63.4 percent of the isolates were susceptible to TMP-SMX with a resistance rate of 28.2 percent. The fluoroquinolones were more effective with susceptibilities ranging from 76 percent to 94.7 percent. Resistance to the fluoroquinolones ranged from 1.3 percent to 2.7 percent. Levofloxacin was the most effective fluoroquinolone tested. Phenotypic dectection of extended spectrum β-lactamases (ESBLs) showed double disc synergy test (DDST) positivity in 59.5 percent of the isolates. Cefepime was the most sensitive indicator cephalosporin in the DDST with 77.3 percent of suspected ESBL-producing isolates showing cefepime-clavulanic acid synergy. Isolates exhibited nine different ESBL phenotypes, however, PCR amplification of the bla genes revealed four isolates that possessed genes belonging to the CTX-M group (CTX-M-1 and CTX-M-8 groups). ESBL genes are usually carried on mobile elements such as plasmids and transposons which may also bear genes that mediate resistance to aminoglycosides, tetracyclines, TMP-SMX and fluoroquinolones. ESBL positive isolates appeared more susceptible to the fluoroquinolones compared to TMP-SMX but there was no significant relationship between ESBL production and susceptibility to these drugs (p > 0.05). The newer fluoroquinolones are a possible alternative treatment option for S. maltophilia infections in this environment but further studies and clinical investigations are needed to determine the in vivo efficacy of these drugs.
- Full Text:
- Date Issued: 2012
Major spoligotype families of Mycobacterium tuberculosis strains isolated from tuberculosis patients in Port Elizabeth, Eastern Cape, South Africa
- Authors: Nqini, Babalwa J
- Date: 2012
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11271 , http://hdl.handle.net/10353/d1006877 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Tuberculosis -- Patients -- South Africa -- Eastern Cape , Drug resistance , Multidrug-resistant tuberculosis -- South Africa -- Eastern Cape , HIV infections -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape
- Description: South Africa is burdened with tuberculosis (TB) which is aggravated by the concurrent epidemic of HIV as well as the emergence of drug resistance. In most developed countries molecular techniques have been used to look at the dynamics of the TB epidemic however, despite the prevalence that is high in sub-Saharan Africa, there is little data on strain types that are available in Port Elizabeth. This study aims to find the major clades of M. tuberculosis that are circulating in Port Elizabeth. Two hundred MDR-TB DNA samples were obtained from the National Health Laboratory Services TB laboratory in Port Elizabeth. Spoligotyping and MIRU-VNTR were used to genotype the strains. Two hundred strains were sent to the University of Stellenbosch for spoligotyping and 179 of those were typed. Spoligotype defined families were further typed by MIRU-VNTR typing, so as to further differentiate and assess clonal diversity within the spoligotype families. The Beijing family was the dominant family and the MANU family being the least dominant, with percentages of 71 percent and 0.5 percent respectively. A comparison of spoligotyping results with the international spoligotyping database (SITVIT2) showed a total of 15 shared international types. Forty four percent (44 percent) of the isolates that were typed by MIRU-VNTR showed similarities, suggesting epidemiological relatedness. Thirty eight percent of isolates from spoligotyping were from the same family, the Beijing family, with the same shared international type STI1, but when typed by 12 MIRU-VNTR they showed no epidemiological relatedness and 18 percent of the isolates showed no relatedness when typed by 12 MIRU-VNTR but spoligotyping showed that they were from the LAM family. Results from our study illustrate the effectiveness of MIRU-VNTR typing together with spoligotyping in epidemiological studies in the region of Port Elizabeth.
- Full Text:
- Date Issued: 2012
Phytochemical analysis and bioactivity of Garcinia Kola (Heckel) seeds on selected bacterial pathogens
- Authors: Seanego, Christinah Tshephisho
- Date: 2012
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11259 , http://hdl.handle.net/10353/420 , Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants , Microbial sensitivity tests , Streptococcal infections , Streptococcus , Staphylococcus aureus infections , Salmonella typhimurium , Traditional medicine
- Description: Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.
- Full Text:
- Date Issued: 2012
Productions of high quality wastewater final effluents remain a challenge in the Eastern Cape Province of South Africa
- Authors: Gusha, Siyabulela Stability
- Date: 2012
- Subjects: Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11265 , http://hdl.handle.net/10353/489 , Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Description: Water is an indispensible and yet a difficult resource to be renewed, thus water scarcity has become one of the major challenges faced worldwide, with the Southern regions of Africa being the most impacted and affected, especially the Eastern Cape Province of South Africa where rural communities depend on receiving waterbodies that are often negatively impacted by wastewater final effluents. This present study was conducted between August and December 2010 to assess the physicochemical and microbial qualities of the final effluents of peri-urban and rural communities based wastewater treatment plants in the Eastern Cape Province. The physicochemical parameters were determined on site and in the laboratory, while bacteriological qualities were determined using culture based techniques. The virological qualities were determined by molecular methods using reverse transcriptase polymerase chain reaction for the target RNA virus and the conventional polymerase chain reaction for the target DNA virus. For both wastewater treatment plants, the physicochemical parameters ranged as follows: chemical oxygen demand (5.95-45 mg/L); total dissolved solids (114.5-187.0 mg/L); salinity (0.12-0.20 psu); temperature (14.2-25.7oC); pH (6.0-7.6); nitrate and nitrites (1.55-6.7 mg/L and 0.023-1.15 mg/L respectively); biological oxygen demand (3.5-7.8 mg/L); turbidity (1.49-6.98 NTU); and chlorine residual (0-2.97 mg/L). Feacal indicator bacteria counts ranged as follows: feacal coliforms (0-1.25×104 cfu/100 ml); total coliforms (0-3.95×104 cfu/100 ml); and enterococci (0-5.0×103 cfu/100 ml). xviii Seventy five percent of the rural community based plant and 80 percent of the peri-urban community based plant were positive for coxsackie A virus, while hepatitis A virus was detected in all the rural community based plant 80 percent of the peri-urban community based plant. This study suggests the need for intervention by appropriate regulatory agencies to ensure regular monitoring of the qualities of final effluents of wastewater treatment facilities in the Eastern Cape Province and ensure compliance to established guidelines.
- Full Text:
- Date Issued: 2012
Studies on bioflocculant production by a consortium of two bacterial species belonging to the Methylobacterium and Actinobacterium genera
- Authors: Ntsaluba, Luvuyo
- Date: 2012
- Subjects: Flocculation , Actinobacteria , Methylobacterium , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11266 , http://hdl.handle.net/10353/482 , Flocculation , Actinobacteria , Methylobacterium , Water -- Purification
- Description: Bioflocculants produced by two identified bacteria: Actinobacterium sp. Mayor and Methylobacterium sp. Obi were investigated with regard to their physicochemical and flocculating characteristics. The two strains were later combined to form a consortium for further studies. The optimum culture conditions for the bioflocculant production were similar for all strains except in the case of Actinobacterium sp. Mayor and the consortium, where glucose was replaced by sodium carbonate as a carbon source. Multi-nitrogen source was the best nitrogen source compare to individual sources for both strains. The divalent cation, Ca2+ proved to be a better flocculating activity stimulus for all produced bioflocculants in this study. The optimum flocculating activities obtained for both individual strains and the consortium were all at alkaline pH. The yield of purified bioflocculant produced by the consortium was 8.203 g/l, while 4.190 g/l and 4.610 g/l were recovered for single strains of Actinobacterium sp. Mayor and Methylobacterium sp. Obi respectively. Further characterization of pure bioflocculants revealed that a bioflocculant dosage of 0.3 mg/ml resulted in the highest flocculating activity for both individual strains while 1.0 mg/ml of the bioflocculant produced by the consortium was required to enhance maximum flocculating efficiency. These bioflocculants proved to be all thermo stable at a temperature range of 20 to 900°C with a heating rate of 10oC/min under a constant flow of nitrogen gas. The presence of functional groups normally required for bioflocculation such as hydroxyl, carboxyl and amino was also detected. The findings of this study suggest that the producedbioflocculants can be utilized as excellent substitutes for harmful synthetic flocculants in both water and wastewater treatments as well as in other industrial applications.
- Full Text:
- Date Issued: 2012
Molecular characterization of the Mycobacterium tuberculosis complex (MTC) of raw milk from selected dairy farms in the Eastern Cape
- Authors: Komani, Nosiphiwo
- Date: 2013
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11276 , http://hdl.handle.net/10353/d1013157 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Description: Tuberculosis (TB) is an ancient infectious disease that has been infecting different populations around the globe and it has also been considered as one of the most successful human and animal disease. TB found in animals such as cattle and other known bovids is known as bovine tuberculosis. Bovine tuberculosis (BTB) is an infectious disease found in cattle mainly caused by Mycobacterium bovis. M. bovis is a member of the Mycobacterium tuberculosis complex (MTC) together with M. tuberculosis, M. africanum, and M. canetti where the natural host is humans; whereas M. caprae, M. microti and M. pinnipedii usually have animals as their natural host. In this study the molecular characterization of the MTC from cow milk in the Eastern Cape was investigated. One hundred and twenty samples (40 ml each) were collected from three dairy farms in the Eastern Cape, South Africa. These samples were processed using a modified Petroff decontamination method. Sample processing was followed by DNA isolation using a Zymo Bacterial/Fungal DNA Kit and the amplification and detection of the MTC was done using the Seeplex MTB Nested ACE assay. The drug susceptibility tests were done using GenoTypeMTBDRplus assay which detects mutations and resistance to INH (isoniazid) and RMP (rifampicin). The milk isolates were further analyzed using a spoligotyping method which is based on the PCR amplification of a highly polymorphic direct repeat locus in the M. tuberculosis genome which detects and types the MTC. A percentage of 20.8 % samples were found to be positive for MTC using the Seeplex MTB Nested ACE assay. There were 42.1 % samples that were resistant to both INH and RMP with the rest sensitive to either INH or RMP. The spoligotyping method showed that 78.3 % samples resembled Family 33 strains and the rest (21.7 %) resembled a spoligotyping signature known to be that of M.africanum. Both these strains belong to the Ancestral lineage with Indo-Oceanic and West Africa 2 lineage. The outcomes of our study showed that molecular methods for detection of MTC can be applied directly on milk samples without the need for culturing.
- Full Text:
- Date Issued: 2013