ABSTRACT
Aim: Vancomycin has been widely used in the treatment of infections caused by methicillinresistant Staphylococcus aureus (MRSA). The emergence of vancomycin- intermediate and - resistant Staphylococcus aureus (VISA and VRSA, respectively) in various parts of the world has been reported. The level of vancomycin resistance phenotypically and genotypically in clinical isolates of S. aureus with or without methicillin resistance from south western region of Nigeria was determined. Methods: A total of 116 non-duplicate S. aureus previously obtained from various clinical specimens were subjected to susceptibility testing using disc and microbroth dilution including polymerase chain reaction amplification of mecA and van genes. Results: The disc susceptibility testing results depict multiple drug resistance with 100% resistance to co-amoxyclav, erythromycin and gentamicin had intermediate of 39.1 and 65.2% respectively, no strain sensitive. Vancomycin showed 100% susceptibility. The minimum inhibitory concentrations, MICs of 116 S. aureus strains against vancomycin showed the isolates to have MIC50 of 1 μg/ml and MIC90 of 2 μg/ml. Five (4.3%) of the 116 clinical isolates had intermediate MIC of 4 μg/ml. These five strains were from methicillin resistant strains and were isolated from different clinical sites and hospitals. However, none of these strains demonstrated the presence of van genes, vanA; vanB; vanC and vanH by PCR. Conclusion: There is high level of multiple antibiotic resistance in S. aureus with some MRSA also showing reduced susceptibility to vancomycin resulting in VISA. However, the VISA strains have shown no van gene as their mechanism of acquiring reduced susceptibility.
ABSTRACT
Aim: To characterize clinical isolates of Candida species from a tertiary hospital in South West Nigeria and also to determine their susceptibility to antifungal agents in order to guide in the course of empirical treatment of patients visiting hospitals in Nigeria. Study Design: This was a cross sectional study. Place and Duration of Study: Medical Microbiology and Parasitology Laboratory, LAUTECH Teaching Hospital, Osogbo, Nigeria. Study duration was Five (5) months. Methods: One hundred and twenty-four Candida species obtained from various body sites were identified and speciated using conventional and analytical profile index (API) for Candida and the susceptibility to 5 antifungal agents was determined using disc and macrodilution methods. Results: Highest number of Candida was obtained from urine, 44 (35.5%); followed by High Vaginal Swabs (HVS), 32 (25.8%) and blood, 20 (16.1%). Highest frequencies were obtained from C. Krusei and C. tropicalis, 32 (25.8%) each, followed by C. Albicans and C. pseudotropicalis, 24 (19.4%) each, and C. gulliermondii,12 (9.7%). Susceptibility to amphotericin B was the highest (74%), followed by itraconazole (52%) while least susceptibility was found in ketoconazole (19.0%). Strains of C. krusei and C. guilliermondii demonstrated 100% resistance to fluconazole and clotrimazole, respectively. MIC50 in most cases were greater than clinical break points and MIC90 values ranged between 16 and >64 μg/ml for all antifungal agents except amphotericin B, 0.5 to 1 μg/ml. Conclusion: Majority of Candida isolates are resistant to azole drugs. Amphotericin B is a reasonable alternative drug for empirical treatment of candidiasis since routine drug susceptibility testing Candida does not exist yet in any hospital in Nigeria.
ABSTRACT
Purpose: Virulence genes play important roles in pathogenesis of infections caused by S. aureus. The aim of this study was to determine the prevalence of PVL, eta and mecA genes in S. aureus isolated from patients in South-Western Nigeria. Materials and Methods: In this study, a total of 116 S. aureus isolates from the clinical specimens submitted to laboratories in tertiary hospitals in the South Western Nigeria were used. Antibiotic susceptibility test was carried out to determine the susceptibility pattern of the isolates using multiple antibiotics disc. Minimum inhibitory concentration (MIC) was also carried out to determine the degree of resistant of the isolates to methicillin. PCR was used to screen for the presence of PVL, eta, and mecAgenes. Results:mecA gene was detected in 48 (41.4%) of 116 strains of S. aureus. The MIC 50 and MIC 90 for mecA negative strains were 1 and 8 μg/ml, respectively while the MIC 50 and MIC 90 for mecA positive were >256 μg/ml. Twenty eight (24.1%) of 116 isolates were PVL gene positive with none of them mecA+. The prevalence of community acquired MRSA (CA-MRSA) was estimated to be 6.9% using molecular techniques. No localization of mecA gene and PVL gene on the genome of the entire S. aureus strains studied. Site of isolation of organism /specimen type was found to be associated with the prevalence of PVL+ and mecA+ S. aureus (P< 0.01). Conclusion: This study concludes that the PVL+ MRSA is rare and the prevalence of CA-MRSA is low in South-Western, Nigeria.
ABSTRACT
BACKGROUND: The use of natural bioactive compounds in conventional chemotherapy is a new direction in cancer treatment that is gaining more research attention recently. Bioactive polysaccharides and polysaccharide-protein complexes from some fungi (edible mushrooms) have been identified as sources of effective and non-toxic antineoplastic agents. Selected oyster mushrooms (Pleurotus pulmonarius and P. ostreatus being local [Nigeria] and exotic strains, respectively) were cultured on a novel medium of yeast extract supplemented with an ethanolic extract of Annona senegalensis, and the antileukemic potential of their metabolites was studied. METHODS: Leukemia was successfully induced in Wister rats by intravenous injection (0.2 mL) of a benzene solution every 2 days for 3 consecutive weeks. The aqueous solution of fungal metabolites (20 mg/mL) produced by submerged fermentation was orally administered (0.2 mL) before, during, and after leukemia induction. Leukemia burden was assessed by comparing the hematological parameters at baseline and after leukemia induction. The immunomodulatory potential of the metabolites was assessed by using a phagocytic assay (carbon clearance method). The ability to enhance leukopoiesis was assessed by using the total leukocyte count. RESULTS: Leukemia induction resulted in significant anemia indices and leukocytosis (P<0.05) in the experimental rats. Both metabolites equally enhanced leukopoiesis and demonstrated phagocytic actions; P. ostreatus activity was significantly higher than that of P. pulmonarius (P<0.05). CONCLUSION: The metabolites exhibited profound antileukemic potential by suppressing leukemia and demonstrating immunotherapeutic activities on animals after oral administration in various experimental groups.