Browsing by Author "John, Cathy Nisha"

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    Association between CD4+T lymphocyte levels and "red complex" pathogens of chronic inflammatory periodontal disease in HIV-positive patients
    (University of the Western Cape, 2012) John, Cathy Nisha; Stephen, L.X.G.
    Background: Infection with HIV results in gradual loss of immunologic functions, especially those mediated by CD4+T helper cells with consequent impairment of the immune response leading to severe manifestations of periodontal disease. The lower the CD4+T lymphocyte cell count or the higher the level of immunosuppression, the higher the incidence of periodontal disease in those patients will be. Putative periodontopathic bacteria namely Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia, commonly referred to as "red complex", and many other bacterial species have been implicated in the initiation and progression of periodontal disease. Objective: The present study tests the association between different CD4+T lymphocyte levels and "red complex" pathogens using BANA, in HIV-positive patients with chronic inflammatory periodontal disease (CIPD). Methods: 120 HIV-positive patients from the infectious disease clinic at Tygerberg hospital participated in the study with a mean age of 33.3 years. The CD4+T lymphocyte counts were obtained from patient's medical records. The six Ramjford teeth were used for evaluating periodontal clinical parameters such as plaque index, gingival index, periodontal probing depth and clinical attachment loss. Subgingival plaque samples were collected and analyzed by the enzymatic BANA test for the detection of the "red complex". Results: The CD4+T lymphocyte mean level was 293.43cells/mm3. Statistically significant associations were found between CD4+T cell counts and probing depth (p= 0.0434) and clinical attachment loss (p= 0.0268). Significant associations were found between BANA with all the clinical indices (p= <0.05). However no association was found between CD4+T cell counts and BANA. Conclusion: HIV-positive patients show a high prevalence of "red complex" pathogens subgingivally. Immunosuppression seems to favour the colonization of these species, resulting in periodontal disease manifestations.
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    Is human immunodeficiency virus (HIV) stage an independent risk factor for altering the periodontal status of HIV-positive patients? A South African study
    (BMC, 2013) John, Cathy Nisha; Stephen, Lawrence Xavier; Africa, Charlene Wilma Joyce
    The immunosuppresion in HIV patients makes them highly susceptible to microbial infections. The aim of the study was to establish whether HIV stage (as depicted by CD4+ T lymphocyte counts) could independently be associated with periodontal status (as revealed by the measurement of clinical indices). One hundred and twenty HIV-infected patients attending an infectious diseases clinic in the Western Cape, South Africa were included in the study. The periodontal clinical indices such as plaque index, gingival index, pocket probing depth and clinical attachment levels were measured on the mesial aspect of the six Ramfjord teeth. The CD4 + T cell counts were taken from the patients’ medical records and patients’ HIV stage determined and grouped according to their CD4+ T cell counts into A (<200 cells /mm3 ), B (200–500 cells /mm3 ) and C (>500 cells /mm3 ).
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    K21 compound, a potent antifungal agent: Implications for the treatment of fluconazole-resistant HIV-associated Candida species
    (Frontiers, 2019-05-24) John, Cathy Nisha; Abrantes, Pedro Miguel dos Santos; Prusty, Bhupesh; Ablashi, Dharam; Africa, Charlene Wilma Joyce
    Background/objectives: With mucocutaneous candidiasis being highly prevalent in HIV patients, the emergence of fluconazole-resistant Candida species forms a major challenge in treating and eradicating these infections. The objective of this study was to establish the antifungal activity of K21, a membrane-rupturing antimicrobial compound derived from a silica quaternary ammonium compound (SiQAC) with tetraethoxysilane (TEOS). Methods: The study sample included 81 Candida species of which 9 were type strains and 72 were clinical isolates. Minimum inhibitory concentrations, synergy, fractional inhibitory concentration index (FICI) and time kill assays were determined by broth microdilution. Electron microscopy (EM) was used to determine the qualitative changes brought about after treatment with K21. Results: K21 inhibited the growth of all fluconazole-resistant and susceptible Candida strains with only 2 hours of exposure required to effectively kill 99.9% of the inoculum, and a definite synergistic effect observed with a combination of K21 and fluconazole. EM demonstrated the presence of two forms of extracellular vesicles indicative of biofilm formation and cell lysis. Conclusion: The study established the efficacy of K21 as an antifungal agent and with fluconazole-resistant candidiasis on the increase, the development of K21 can provide a promising alternative to combat acquired drug resistance.