Abstract

Coagulase-negative staphylococci (CNS) are a major cause of nosocomial infection, especially in critically ill and immunocompromised patients. CNS is usually a multi-drug resistant and glycopeptide antibiotics that have been considered to date, the drug of choice for treatment. The aim of this study was to characterize CNS with reduced susceptibility to glycopeptides isolated from the respiratory tract of HIV positive patients from the Limpopo Province in South Africa between 2007 and November 2008. A total of 185 sputum samples were collected from HIV positive drug naive patients and analyzed for antibiotics resistant profiles of the coagulase-negative staphylococci isolates. The isolates were tested for susceptibility to extracts from five medicinal plants commonly used in the Venda region of Limpopo Province. Of a total of 185 sputum samples investigated, 88 were positive for CNS and all of this displayed reduced susceptibility to glycopeptides. Species distribution was as follows: Staphylococcus auricularis(5), Staphylococcus capitis (6), Staphylococcus hominis (23), Staphylococcus epidermidis(36) and Staphylococcus saprophyticus (18). The incidence of oxacillin, linezolid, daptomycin, imipenem and meropenem resistance was 100%. Evaluation of plant extracts against representative of the isolates showed all the extracts from the bark of medicinal plants to have inhibitory effect on their growth. There is high prevalence of vancomycin resistant CNS among HIV positive patients who participated in this study. This prevalence is quite alarming as this is the only drug of choice since methicillin resistance among this group of organisms is equally quite common. The plant extracts demonstrated antibacterial activity as they inhibited the growth of the isolates they were tested for. Surveillance by anti-biotyping with attention to multi-resistant profile, and warning to clinicians, is necessary. Similarly, further investigation is needed to identify the chemical composition of the active antibacterial compounds in the plant extracts.

Key words: Coagulase-negative staphylococci, vancomycin, antibiotic resistance, plant extracts, HIV