Thesis (MA (Counselling Psychology))--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 18, 2007) Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 73-87).

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 27, 2007) Includes bibliographical references.

Th.--Méd.--Paris, 1905-1906. / Paris, 1905-1906, tome 10, n ° 210.

Th.--Méd.--Reims, 1981. N°: 1.

The basidiomycetous yeast Malassezia has been linked to a number of disease states such as seborrhoeic dermatitis, dandruff and pityriasis versicolor. Much confusion has arisen as to its role in these disease states as this fungus is found inhabiting the stratum corneum of approximately 90% of the human adult population. Malassezia yeasts are lipophilic organisms, some species showing a specific requirement for long chain fatty acids for in vitro culture. The object of the experiments undertaken in this study was to elucidate the role of Malassezia yeasts in dandruff and seborrhoeic dermatitis.

Neonatal sickness and death is increasingly becoming a public health problem worldwide. The colonization of Group B Streptococcus and Staphylococcus in the rectovaginal area is among the sources of infections in neonates which can result in illness and mortality. The over exposure of humans to antibiotics is the possible cause of resistance in bacteria. These resistant strains can be passed onto offspring, leading to resistant infections and increasing the morbidity of neonates because of treatment failures. Many people, including healthcare personnel are not aware of the effect of these bacteria, and informing clinics and hospitals can help create awareness and monitoring the levels of resistance among bacteria can assist in preventing the transference of the bacteria. In this study we investigated the prevalence of group B Streptococcus (GBS) and Staphylococcus aureus in the anogenital tract of pregnant women in the Eastern Cape Province, South Africa. A total of 49 isolates from 25 (30.5 percent) pregnant women colonized with GBS were isolated from vaginal and rectal swabs of 82 pregnant women at 25-37 gestation who participated in this study. These isolates were obtained using standard microbiological methods and confirmed by polymerase chain reaction (PCR) technique aimed at the ScpB gene. The isolates were further screened for the presence of 9 serogroups (Ia, Ib, II, III, IV, V, VI, VII, VII) and serogroups Ib 2 (4.8 percent), II 20 (40.8 percent) and IV 5 (10.2 percent) and 22 non-typable (44.9 percent) were identified. Susceptibility profiling of the isolates to 12 antibiotics (tetracycline, clindamycin, erythromycin, gentamycin, naladixic acid, norfloxacin, chloramphenicol, cefuroxime, cefotaxime, imipenem, penicillin and vancomycin) was tested in vitro by the standardized disc diffusion method. All the confirmed GBS isolates (49) were resistant to erythromycin, tetracycline and clindamycin. A higher percentage of the isolates were resistant to gentamycin 44 (90 percent), nalidixic acid 41 (84 percent), penicillin 41 (84 percent), chloramphenicol 38 (78 percent), cefuroxime 36 (74 percent), imipenem 36 (74 percent), cefotaxime 35 (71 percent), norfloxacin 32 (65 percent) and vancomycin 31 (78 percent). Multiple antimicrobial resistance patterns ranged from 9‒11 and indices ranged from 0.7‒0.9, respectively. Among the antimicrobial resistance determinants examined, genes encoding for resistance to erythromycin ermB 25 (51 percent), tetracycline tetM 32 (65 percent) and penicillin bla-Z 4 (8 percent) only were identified. On the other hand, screening for S. aureus yielded a total of 7 isolates from 4 study participants as confirmed by PCR based on staphylococcal, nuc gene. The isolates were further screened for the presence of six virulence genes (Hla, Hlb, LUKM, LUKED, PVL, Eta and Etb) and antibiotic susceptibility pattern by the disc diffusion method using 12 (penicillin, vancomycin, tetracycline, rifampicin, imipenem, gentamycin, chloramphenicol, norfloxacin, oxacillin, erythromycin and sulfamethoxazole-trimethoprim) antibiotics that are adopted in the treatment of infections caused by the organism. PVL 6 (85.7 percent) and eta 1 (14.3 percent) were the two virulence genes detected. The following percentages of antibiotics resistance among the isolates were observed; penicillin G 7 (100 percent), clindamycin 7 (100 percent), vancomycin 5 (100 percent), rifampicin 5 (71 percent), oxacillin 5 (71 percent), erythromycin 5 (71 percent) gentamycin 3 (43 percent), norfloxacin 3 (43 percent), sulfamethoxazole-trimethoprim 3 (43 percent), chloramphenicol 2 (29 percent), imipenem 1 (14 percent). Multiple antimicrobial resistance patterns ranged from 7‒8 and indices ranged from 0.6‒0.7, respectively. Genetic profiling of the resistance genes identified erythromycin ermB 5(71.4 percent), tetracycline tetM 5(71.4 percent) and penicillin bla-Z 1(14.3 percent) only. The findings from the study have revealed GBS and S. aureus colonization of pregnant women in the Eastern Cape Province, and these have great public health implications especially for the neonates who are mostly likely to be infected during birth. The unidentifiable multidrug resistant serogroups of GBS as well as resistant S. aureus limit the choice of drugs in the management of infections caused by these pathogens more so if transmitted to infants. Therefore asymptomatic pregnant women needed to be properly educated about the bacteria as well as the precautions that need to be taken.

Synthesis of polysaccharide intercellular adhesin (PIA), accumulation associated protein (Aap) and extracellular matrix binding protein (Embp) are major mechanisms used by Staphylococcus epidermidisto evade immunity through biofilm formation. These evasion strategies are particularly suited for colonisation of medical devices such as heart valves, joint prostheses and central venous catheters resulting in significant patient morbidity. Two biological activities of PIA, Aap and Embp contribute to their role as an evasion molecules. Firstly their ‘barrier’ function limiting penetration of immune cells and antibiotics. Secondly, their ‘immunomodulatory’ properties which influence cytokine responses. At present little is known about these functional activities in physiological media and biological fluids. This thesis uses a cell biology approach to study the environment necessary for PLA production. Specifically in vitromodelling of biofilm formation, PIA production and S. epidermidisleukocyte co-culture experiments have been used to assess conditions that are conducive for PIA production. This thesis has identified that:• Specific cell culture media cause unique profiles of biofilm accumulation with differential production of PIA, Aap and Embp. • Fetal bovine serum and pooled human serum support S. epidermidisgrowth but differentially affect biofilm formation by PIA, Aap and Embp. • Large scale production of PIA (~20mg) can be achieved by culturing in Iscove's Modified Dulbecco's Media which has allowed streamlining of current isolation procedures. • PIA induction of cytokines, including IL-8 and TNF is dependent on being tethered to the bacterial membrane. • Macrophages can penetrate into a S. epidermidisproduced PIA ‘barrier’. • Immunosuppression of whole blood with dexamethasone unmasks the pathogenic advantage of PIA in S. epidermidis expressing PIA compared to negative controls. • Whole blood killing of S. epidermidisis dependent on CD1 lb/CD 18. • PIA induces whole blood killing dysfunction which is likely related to C5a production. • PIA can be produced in a whole blood environment.• Inocula of -1 0 colony forming unit of S. epidermidisare required to form biofilms in whole blood. This study suggests the importance of studying clinically important biofilm production mechanisms under conditions that closely resemble those in human disease.