Charlene W.J. Africa
University of the Western Cape
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Featured researches published by Charlene W.J. Africa.
Diagnostic Microbiology and Infectious Disease | 2014
Pedro Miguel dos Santos Abrantes; Carole P. McArthur; Charlene W.J. Africa
Candida species are a common cause of infection in immune-compromised HIV-positive individuals, who are usually treated with the antifungal drug, fluconazole, in public hospitals in Africa. However, information about the prevalence of drug resistance to fluconazole and other antifungal agents on Candida species is very limited. This study examined 128 Candida isolates from South Africa and 126 Cameroonian Candida isolates for determination of species prevalence and antifungal drug susceptibility. The isolates were characterized by growth on chromogenic and selective media and by their susceptibility to 9 antifungal drugs tested using the TREK™ YeastOne9 drug panel (Thermo Scientific, USA). Eighty-three percent (82.8%) of South African isolates were Candida albicans (106 isolates), 9.4% were Candida glabrata (12 isolates), and 7.8% were Candida dubliniensis (10 isolates). Of the Cameroonian isolates, 73.02% were C. albicans (92 isolates); 19.05% C. glabrata (24 isolates); 3.2% Candida tropicalis (4 isolates); 2.4% Candida krusei (3 isolates); 1.59% either Candida kefyr, Candida parapsilopsis, or Candida lusitaneae (2 isolates); and 0.79% C. dubliniensis (1 isolate). Widespread C. albicans resistance to azoles was detected phenotypically in both populations. Differences in drug resistance were seen within C. glabrata found in both populations. Echinocandin drugs were more effective on isolates obtained from the Cameroon than in South Africa. A multiple-drug resistant C. dubliniensis strain isolated from the South African samples was inhibited only by 5-flucytosine in vitro on the YO9 panel. Drug resistance among oral Candida species is common among African HIV patients in these 2 countries. Regional surveillance of Candida species drug susceptibility should be undertaken to ensure effective treatment for HIV-positive patients.
International Journal of Environmental Research and Public Health | 2014
Charlene W.J. Africa; Janske Nel; Megan C. Stemmet
The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.
Virulence | 2011
Charlene W.J. Africa
Background: Preterm birth significantly impacts on neonatal morbidity and mortality and is apparently increasing world-wide. Several studies have attempted to define a causative role for periodontal disease in adverse pregnancy outcomes but few have focused on the microbiology of periodontal disease in relation to these outcomes. Results: The evidence for a positive correlation is strong, supported by microbiological and immunological findings. Conflicting results are often associated with uncontrolled confounding factors. Materials and Methods: A literature search was conducted in order to establish whether or not a role exists for oral Gram-negative bacteria in adverse pregnancy outcomes. Association and intervention studies are summarized along with pathogenic potential of the Gram-negative bacteria most frequently implicated in periodontal disease.
Virulence | 2010
Charlene W.J. Africa; Janet Kayitenkore; Claude Bayingana
Background: Reports show that more than 20 million infants world-wide are born prematurely with 95 % of all pre-term births occurring in developing countries. Oral colonization of Gram-negative anaerobes has been implicated as a risk factor for preterm delivery of low birth weight infants. Materials and Methods: This study comprised 200 women admitted to the department of obstetrics and gynecology of the teaching hospital of Butare in Rwanda. Gingival crevicular fluid was collected from each quadrant of the mothers mouth (using paper points) within 24 hours of delivery. A dichotomous score of presence or absence of gingival inflammation was recorded for each patient along with demographic data such as age, marital status etc. Samples were examined by PCR for the presence of Aggregatibacter actinomycetemcomitans and selected members of the red and orange complexes described by Socransky et al., (1998), and their presence associated with age, gingival inflammation and pregnancy outcomes. Results: Association of bacterial species with the risk of periodontal disease and thus the risk of preterm delivery was only observed when they occurred in pairs or groups of three or more. Aa appeared to be a necessary co-factor for significant associations of bacterial groups with the variables recorded.
International Dental Journal | 2017
Mervyn Turton; Charlene W.J. Africa
BACKGROUND Although there is increasing evidence to suggest an association between periodontal disease and adverse pregnancy outcomes, the issue remains controversial. STUDY OBJECTIVE This study tested the hypothesis that periodontal disease is a risk indicator for preterm delivery of low-birthweight infants. MATERIALS AND METHODS The study sample comprised 443 pregnant women with a mean (± standard deviation) age of 24.13 (±5.30) years. At first visit, maternal oral health status was assessed by the measurement of probing pocket depth and clinical attachment loss, and periodontal status was graded as absent, mild, moderate or severe. An association was sought between pregnancy outcomes and maternal periodontal status. RESULTS While controlling for other factors, significant associations were found between pregnancy outcomes and maternal periodontal index scores. CONCLUSION This study provides further evidence that periodontal disease is a risk indicator for adverse pregnancy outcomes.
International Journal of Dentistry | 2012
Cathy Nisha John; Lawrence Xavier Stephen; Charlene W.J. Africa
Background. The “red complex” microorganisms, namely, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia are considered as potential pathogens causing HIV-associated periodontal diseases. Moreover, it has been recognized that an association exists between CD4+ T cell counts and periodontal disease progression. Objective. To establish whether CD4+ T cell counts or oral hygiene plays a greater role in producing BANA-positive results in HIV-associated periodontal disease. Materials and Methods. One hundred and twenty HIV-positive patients participated in the study, and their CD4+ T cell counts were obtained from their medical records. The six Ramfjord teeth were used for evaluating periodontal clinical indices and subgingival plaque sampling. BANA test was used for the detection and prevalence of the “red complex” bacteria in plaque samples. Results. A majority of 69.17% HIV-positive patients were BANA-positive. No significant associations were found between BANA and CD4+ T cell counts. A highly significant association was found between BANA with probing depth and clinical attachment level (P ≤ 0.0001) and between BANA and the use of interdental aids (P = 0.0168). Conclusion. HIV-associated periodontal diseases are strongly related to oral hygiene practices rather than the effect of CD4+ T cell counts, and the use of interdental aids was marked as a significant predictor of BANA-negative plaque samples.
Frontiers in Public Health | 2018
Evelyn Kaambo; Charlene W.J. Africa; Ramadhani Chambuso; Jo-Ann S. Passmore
A healthy vaginal microbiota is considered to be significant for maintaining vaginal health and preventing infections. However, certain vaginal bacterial commensal species serve an important first line of defense of the body. Any disruption of this microbial barrier might result in a number of urogenital conditions including aerobic vaginitis (AV) and bacterial vaginosis (BV). The health of the vagina is closely associated with inhabitant microbiota. Furthermore, these microbes maintain a low vaginal pH, prevent the acquisition of pathogens, stimulate or moderate the local innate immune system, and further protect against complications during pregnancies. Therefore, this review will focus on vaginal microbial “health” in the lower reproductive tract of women and on the physiological characteristics that determine the well-being of reproductive health. In addition, we explore the distinct versus shared characteristics of BV and AV, which are commonly associated with increased risk for preterm delivery.
Biomarkers | 2017
Mervyn Turton; Charlene W.J. Africa; Ralf Henkel; Charlene W. J. Africa
Abstract Introduction: Although the association between periodontal disease (PD) and adverse pregnancy outcomes has gained recognition amongst antenatal healthcare workers, not much has changed in practice to address it. This prospective study tested the hypothesis that BANA (N-benzoyl-DL-arginine-2-naphthylamide), a diagnostic test for PD, may inform obstetricians and other antenatal healthcare practitioners, of the risk of adverse pregnancy outcomes in mothers attending antenatal clinics. Methods: At first visit, the presence of suspected periodontopathogens was assessed by BANA testing of dental plaque from 443 mothers attending antenatal clinics in KwaZulu-Natal, South Africa and an association later sought with pregnancy outcomes. The accuracy of BANA to predict adverse pregnancy outcomes was evaluated by the calculation of likelihood ratios. The study complied with the Declaration of Helsinki. Results: Significant differences were found between pregnancy outcomes of BANA-negative and BANA-positive mothers (p < 0.0001). BANA showed sensitivity and negative predictive values of 87% and 91%; 75% and 78%; 87% and 94% in detecting low birth weight, preterm delivery, and preterm low birth weight delivery respectively. Conclusion: This study confirms that BANA may indicate the need for periodontal therapy to reduce the risk of adverse pregnancy outcomes and could form part of the routine antenatal examination.
BDJ Open | 2017
Kim Smeda-Pienaar; Eveline Kaambo; Charlene W.J. Africa
Background:Listgarten and Hellden (1978) used darkfield microscopy of wet mounts to differentiate between healthy and periodontally diseased sites in the mouth by expressing the different bacterial morphotypes observed as a percentage of the total number of bacteria counted. This method of periodontal disease assessment gained favour as a diagnostic tool but presented with the limitation of immediate examination to determine the number of motile rods present and an inability to distinguish between gingivitis and periodontitis. Grading of bacterial morphotypes into several distinct categories of health or disease (Ison and Hay, 2002), simplified the scoring system of Gram-stained smears for the diagnosis of bacterial vaginosis (Nugent et al. 1991). The application of a similar grading system using stained smears rather than wet mounts could be advantageous to the diagnosis of periodontal disease.Objectives/aims:This study tested the hypothesis that stained smears of dental plaque collected from the gingival crevice of individuals with varying probing pocket depths (PD) may provide a grading system for periodontal disease assessment.Materials and methods:Subgingival plaque samples were collected from 49 patients, stained with a silver stain and the proportions of each bacterial morphotype graded relative to their respective PD measurements.Results:This technique allowed for a grading system of I–IV, with grade I indicating health and grade IV indicating severe periodontal disease.Discussion:Stained smear examination eliminates the time restriction for motile rod enumeration and allows for storage of smears for future reference.Conclusion:Standardization of the microscopic areas to be evaluated or examined will facilitate the agreement of cut-off values for the diagnosis of periodontal disease.
F1000Research | 2016
Charlene W.J. Africa; Pedro Miguel dos Santos Abrantes
Background: Candida infections are responsible for increased morbidity and mortality rates in at-risk patients, especially in developing countries where there is limited access to antifungal drugs and a high burden of HIV co-infection. Objectives: This study aimed to identify antifungal drug resistance patterns within the subcontinent of Africa. Methods: A literature search was conducted on published studies that employed antifungal susceptibility testing on clinical Candida isolates from sub-Saharan African countries using Pubmed and Google Scholar. Results: A total of 21 studies from 8 countries constituted this review. Only studies conducted in sub-Saharan Africa and employing antifungal drug susceptibility testing were included. Regional differences in Candida species prevalence and resistance patterns were identified. Discussion: The outcomes of this review highlight the need for a revision of antifungal therapy guidelines in regions most affected by Candida drug resistance. Better controls in antimicrobial drug distribution and the implementation of regional antimicrobial susceptibility surveillance programmes are required in order to reduce the high Candida drug resistance levels seen to be emerging in sub-Saharan Africa.