1 |
Characterization of probiotic Lactobacillus spp. isolates from commercial fermented milksFarahmand, Nasim January 2015 (has links)
The aim of this project was to study the identity of probiotic lactobacilli in fermented milk products from the United Kingdom/European markets during their survival during shelf-life. This in vitro study was also aimed at undertaking studies on some of the physiological probiotic criteria, such as resistance to stomach/intestine conditions and also possible functional properties of the isolates, such as antimicrobial activities, antibiotic resistance/susceptibility and antibiotic resistance genes, biofilm formation and production of conjugated linoleic acid (CLA). Primarily, a comparative study was carried out on selectivity of MRS-Clindamycin, MRS-Sorbitol and MRS-IM Maltose, to select the right medium for enumeration of probiotic Lactobacillus. Based on selectivity of medium for recovery of the targeted lactobacilli and also simplicity of preparation, MRS-Clindamycin was chosen as the best medium for enumeration of probiotic Lactobacillus in fermented milks. The results of enumeration of lactobacilli showed that 22 out of a total 36 tested products contained more than 106 colony forming units/g at the end of their shelf-life, which comply with the recommended minimum therapeutic level for probiotics. Rep-PCR using primer GTG-5 was applied for initial discrimination of isolated strains, and isolates, which presented different band profile, were placed in different groups. The isolated Lactobacillus spp. were identified mainly as Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus paracasei by analysis of partial sequences of the 16S ribosomal RNA and rpoA genes. In order to characterize the isolates for probiotic properties, this study was focused on six Lactobacillus isolates along with two commercial Lactobacillus cultures from Chr. Hansen (Lactobacillus acidophilus La5 and Lactobacillus casei C431) and three Lactobacillus type strains (Lactobacillus casei subsp. casei, Lactobacillus paracasei subsp. paracasei and Lactobacillus acidophilus) which were purchased from NCIMB. The stomach and intestine conditions were mimiced using a batch culture fermentation system, and the combined effects of pH, enzymes and bile salts on survival of tested isolates was tested. The tested isolates were able to survive at low pH environment and also high concentrations of bile salts of the upper digestive tract. The potential of tested isolates for biofilm formation was determined in different conditions of nutritional and physiological stresses. The capability of tested isolates to produce biofilm in nutrient rich medium was recorded. However, the growth limitation, such as nutrient shortage in diluted media and also using inulin rather than glucose in synthetic medium, did not induce biofilm formation. Antimicrobial activities of tested bacteria against indicator bacteria namely Escherichia coli NCTC 12900, Salmonella enterica serovar Typhimurium DT124 and Salmonella enterica serovar Enteritidis PT4 and Lactobacillus delbruckii subsp. bulgaricus were studied. The production of organic acids and bacteriocin was considered as key mechanisms for antimicrobial activity of tested strains. Screening the isolates competence for production of CLA demonstrated that this feature is species dependent and also entirely related to the level of initial linoleic acid in the medium. Eleven tested isolates were also assessed for their antibiotic resistance profile by determination of minimum inhibitory concentration (MIC). The acquired resistance to cefoxitin, ceftriaxone, chloramphenicol, erythromycin, gentamycin, kanamycin, lincomycin, streptomycin, tylosin tartarate, tetracycline and vancomycin was observed in all tested isolates. Also their genetic background of antibiotic resistance genes was studied by PCR reactions and none of the tested isolates showed positive bands for investigated resistance genes.
|
2 |
Thesis portfolio for the Professional Doctorate in Health PsychologyHawkin, Lucinda January 2018 (has links)
Background: Breastfeeding rates continue to remain low in the UK even though a number of initiatives have been delivered in an attempt to increase them. Evidence suggests a large proportion of mothers now perceive breastfeeding as the best feeding practice for their baby and many wish to do so, but are unable to for a number of reasons including issues around breastfeeding in public. This study set out to explore lived experience of breastfeeding in public to better inform our understanding. Methods: A qualitative approach was chosen using semi-structured interviews to facilitative an in-depth exploration of mothers’ experiences of public breastfeeding. Women aged 31 to 40 years old who had experience of breastfeeding in public within London were interviewed and narratives analysed using Interpretative Phenomenological Analysis. Results: Two themes emerged from the data: “Societal attitudes as ostracising” and “Becoming a nursing mother”. It was evident these mothers experienced a strong transference from a British society generally disapproving and feeling uncomfortable with breastfeeding. Consequently implicit expectations are placed on them to conceal the behaviour either by covering their breast or breastfeeding in discrete locations including feeding rooms. Transitioning from a woman to a mother is a significant life stage and being able to breastfeed successfully appeared to be an important aspect of motherhood for these mothers. Their determination to breastfeed exceeded the challenges they faced in public with their confidence enhancing with time. Findings are considered in light of current social attitudes and the importance of normalising views about breastfeeding in society in order to improve health outcomes.
|
3 |
Collective resource mobilisation for economic survival within the Turkish speaking communities in LondonKaran, Olgu January 2015 (has links)
This study aims to generate insights into the business start-up and maintenance activities of Kurdish and Turkish business owners in catering and retail sectors in North London by utilizing a new theoretical approach influenced by Charles Tilly’s (1978) collective resource mobilisation theory. The research objectives are: - to examine the reasons behind the formation of business start-ups for Kurdish and Turkish business owners in the catering and retail sectors; - to identify and investigate the ways in which the ‘forms of capital’ (Bourdieu, 1986) are acquired and mobilised for starting and maintaining these businesses. Methodologically, the research draws on extensive fieldwork with 65 participants. The thesis draws on qualitative research methods that enable the participants’ business start-up and maintenance experiences to be analysed in the context of the existing literature, and allows for the generation of a new theoretical approach to emerge based on their explanations. The thesis makes theoretical and empirical contributions to the field of study. Empirically, it sheds light onto two ‘invisible communities’ that are largely concentrated in the catering and retail sectors. The field study for this project presents an original contribution by examining business start-up and maintenance activities of the Turkish and Kurdish communities. Theoretically, the business start-up and maintenance activities of Kurdish and Turkish business owners are analysed through the lens of collective resource mobilisation theory. This has three components: interests, mobilisation of networks and opportunity structure. The three components provide an analytical framework for examining the interplay between agency and structural influences on the start-up and maintenance activities of Kurdish and Turkish business owners.
|
Page generated in 0.0781 seconds