Experiences of midwives caring for mothers who have lost their babies at birth
- Authors: Dasi, Peggy
- Date: 2016
- Subjects: Obstetrics , Midwives , Perinatal death -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10948/9000 , vital:26454
- Description: Midwives working in labour wards usually have the pleasure of delivering a live baby and rejoicing with the mother. However, the delivery could become tragic for the mothers and midwives when the baby dies at birth due to pregnancy related complications. The result is that midwives have to render care and support to mothers who have lost their babies at birth. The objectives of this study were to explore and describe the experiences of midwives caring for mothers who have lost their babies at birth. A qualitative explorative, descriptive and contextual design was used to conduct this research study to gain an understanding of how the midwives experienced caring for mothers who have lost their babies at birth. A purposive criterion based non-probability sampling method was used. Ten semi-structured face-to-face interviews were conducted to collect data. Ethical considerations were observed throughout the research study. Measures of trustworthiness were ensured by using credibility, transferability, dependability and conformability. Data analysis was done using Tesch’s method to make sense out of text and data. Four themes were identified, namely, Midwives shared their diverse experiences relating to caring for mothers who have lost their babies at birth; Midwives expressed how their personal values and beliefs influenced the ways they dealt with babies dying at birth; Midwives described the organizational values and beliefs related to death and dying and how this influences their own experiences and lastly Midwives provided suggestions regarding how they can be assisted in caring for mothers who have lost their babies at birth. Two main guidelines were developed based on the research findings and literature. The study concludes with recommendations made with regard to areas of nursing practice, education and research.
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- Date Issued: 2016
Application of bacteriocins in the preservation of fruit juice
- Authors: Bodley, Mark David
- Date: 2015
- Subjects: Bacteriocins , Fruit juices -- Preservation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10345 , http://hdl.handle.net/10948/d1020188
- Description: Bacteriocins (BCNs) are ribosomally synthesized polypeptides or proteins with antimicrobial activity, produced by different groups of bacteria. Many lactic acid bacteria (LAB) produce BCNs with broad spectra of inhibition. The antimicrobial activity of BCNs against spoilage organisms (SPOs) has raised considerable interest in their application in juice preservation. The objectives of the study were to: (i) isolate, identify and screen BCN producing bacteria for antimicrobial activity against spoilage bacteria and fungi, (ii) optimize production of BCN from selected producers and (iii) investigate the industrial application of the BCN as a preservative in fruit juice. Eleven LAB strains of BCN producers were screened for antimicrobial activity. BCNs from Lactobacillus plantarum and Pediococcus pentosaceus 34 were the most effective against juice spoilage bacteria and fungi. The effect of medium components on bacteriocin production in L. plantarum and P. pentosaceus 34 was also determined. Clementine:Valencia (1:1) juice was used for the first time as the growth medium for L. plantarum and P. pentosaceus 34. The BCN from L. plantarum showed the highest activity and was, therefore, chosen for juice fermentation studies. The identification of L. plantarum was confirmed by biochemical tests, polymerase chain reaction (PCR) and sequencing of the recA gene. The highest BCN activity was observed for L. plantarum grown in De Man-Rogosa-Sharpe (MRS) and a combination of all supplements (i.e. peptone, MnSO4.H2O, Tween 80, glucose and whey), followed by MRS and Tween 80, peptone, MnSO4.H2O and MRS alone. MRS was a better medium for BCN production than juice [Clementine:Valencia (1:1)]. Size exclusion chromatography (SEC) was used to isolate the active L. plantarum BCN fraction which corresponded to an approximate molecular weight of 3.2 kDa and was proteinaceous in nature. Plantaricin structural genes (plnEF, plnJ, plnK, plnN) were detected in the L. plantarum strain by PCR and sequenced, and were chromosomally encoded as no plasmids could be detected. This implies that the BCN from L. plantarum is most likely a type of class IIa plantaricin which is responsible for the broad inhibitory activity observed. For the industrial application studies, L. plantarum BCN-containing cell free supernatant (BCNsup) added to “Ready to Drink” (RTD) Clementine:Valencia (1:1) juice at concentrations of 3 600 - 500 000 ppm decreased growth of SPOs, Lactobacillus acidophilus and Streptococcus thermophilus. At 250 000 ppm, the L. plantarum BCNsup achieved 5.3 and 6.8 log reductions of the L. acidophilus, after 24 and 48 h, respectively, which is larger than the USFDA (2001) requirement of a 5 log reduction in SPO activity, for preservation of fruit juices. However, there was a decrease in the activity when the BCNsup was applied to industrial (Valor) RTD juice (mango-orange) at decreasing concentrations of 100 000, 50 000 and 25 000 ppm. Organoleptic tests showed that the BCN did not alter flavor or taste of the juice and did not cause toxicity or allergic reactions. A food safety risk assessment was conducted in order to determine the Critical Control Point(s) [CCP(s)] at which the BCN could be applied to control identified microbiological hazards, and a Hazard Analysis and Critical Control Point (HACCP) plan was developed. This is the first report on the optimisation of L. plantarum BCN production in juice [Clementine:Valencia (1:1)], followed by inoculation into RTD juice (mango-orange), including a HACCP plan for the application of the BCN as a preservative in juice.
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- Date Issued: 2015