Browsing by Author "McArthur, Carole P."

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    Antimicrobial resistant Gram-positive cocci in pregnant mothers with aerobic vaginitis
    (Infection Control Africa Network (ICAN), 2016) Kaambo, Eveline; Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
    The vaginal microbiota of a healthy asymptomatic woman consists of an extensive diversity of anaerobic and aerobic bacterial genera and species dominated by the microaerophilic genus Lactobacillus , known to inhibit the growth of potentially pathogenic non-acid tolerant microorganisms. An imbalance of species within this biofilm may result in endogenous opportunistic infections such as aerobic vaginitis (AV) caused by S. agalactiae and E. faecalis, which have been implicated in neonatal and obstetric sepsis. The prevalence and antimicrobial susceptibility of E. faecalis and S. agalactiae in pregnant women with AV in the Western Cape, South Africa was determined using standard microbiological culture methods and the Sensititre TREK system. AV was detected in 26.13% of the 199 tested pregnant women, with S. agalactiae and E. faecalis isolated from 32 and 20 mothers respectively. S. agalactiae and E. faecalis showed resistance to 12 of the 17 antibiotics tested, including those recommended for prophylaxis according to the CDC guidelines. The resistance of S. agalactiae and E. faecalis to commonly administered antimicrobials highlights the need for alternative treatment regimens for AV during pregnancy to reduce the risk of AV-associated negative pregnancy outcomes.
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    A comparison of susceptibility patterns of oral Candida isolates from South African and Cameroonian HIV- positive populations
    (The International Association for Dental Research (IADR), 2012) Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
    METHOD: In this study, Candida isolates were collected from the oral mucosa of 128 South African and 126 Cameroonian HIV-positive patients, by scraping the mouths of consenting patients using sterile cotton swabs. Ethics clearance for this project was granted by the University of the Western Cape. Confirmation of Candida species was done by growth on differential media, Gram staining and microscopy. The isolates were grown on selective media and differentiated using two commercial chromogenic agars and Tomato (V8) agar. Changes in colony colour, morphology and pseudohyphae/chlamydospore expression could then be observed, allowing for species differentiation. Isolates were also examined for antifungal susceptibility patterns using the TREK system. RESULT: The results from this study suggest that the prevalence of Candida species varies according to geographical region and HIV-subtype. Discrepancies in antifungal drug susceptibility patterns were also observed in the two populations. CONCLUSION: The emerging drug-resistance raises the need for increased species prevalence surveillance, as this information can have clinical implications in the choice of more appropriate and effective patient treatment.
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    Drug susceptibility profiles of Candida species isolated from the oral mucosa of HIV-positive West African patients using the TREK Sensititre system
    (2013) McArthur, Carole P.; Abrantes, Pedro Miguel dos Santos; Awasom, Charles; Ayuk, L.; Africa, Charlene W.J.
    BACKGROUND: Candida infections are a common cause of death in immunocompromised patients. The prevalence and anti-mycotic drug susceptibility profiles of Candida species from Cameroon in Africa are unavailable. This study was prompted by an increasing incidence of treatment failure. Drug susceptibility profiles, necessary to improve treatment outcomes, is particularly important in countries where the sale of antimicrobials and antifungals is uncontrolled and resistance may emerge due to the indiscriminate use. OBJECTIVE: The goal of this study was to characterize and determine drug susceptibility of oral Candida species in Cameroonian patients with HIV/AIDS. MATERIALS AND METHODS: Candida species were isolated from the oral cavity of 126 HIV-positive patients attending a local HIV/AIDS clinic in the Cameroon. Drug susceptibility to azoles and echinocandins was determined using the commercial TREK Sensititre® YeastOne™ platform that provides the minimal inhibitory concentration of amphotericin B, 5-flucytosine, anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole, and voriconazole. RESULTS: Ninety two isolates identified were Candida albicans. Remaining isolates were C. glabrata (24), C. tropicalis (4), C. krusei (3), C. parapsilopsis/lusitanreae/keyfr (2), and one isolate was C. dubliniensis. More than 50% of C. albicans isolated were resistant to azoles but 115 Candida species (87%) were susceptible to amphotericin B. Twenty one of the twenty four C.glabrata identified (88%) were resistant to micafungin. The majority of Cameroonian Candida species were sensitive to flucytosine (5-FC) (95%) and echinocandins (79%). CONCLUSIONS: The report of azole resistance in all Candida species isolated from immunocompromised patients in Cameroon is a new and important observation. We found the approach using a broad screening platform an effective means to obtain data rapidly. We propose confirmation of these data and regional surveillance of Candida species in other areas in Cameroon and surrounding countries to develop an effective public health management and treatment strategy.
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    Multi-drug resistant (MDR) oral Candida species isolated from HIV-positive patients in South Africa and Cameroon
    (Elsevier, 2014) Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
    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 nine antifungal drugs tested using the TREK™ YeastOne9 drug panel (Thermo Scientific). Eighty three percent (82.8%) of South African isolates were C. albicans (106 isolates), 9.4% were C. glabrata (12 isolates) and 7.8% were C. dubliniensis (10 isolates). Of the Cameroonian isolates, 73.02% were C. albicans (92 isolates); 19.05% C. glabrata (24 isolates); 3.2% C. tropicalis (4 isolates); 2.4% C. krusei (3 isolates); 1.59% either C. kefyr, C. parapsilopsis or C. 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 (MDR) 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 two countries. Regional surveillance of Candida species drug susceptibility should be undertaken to ensure effective treatment for HIV-positive patients.