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Biography

Okoh hold a Bsc (Hons), Msc and PhD degrees in Microbiology. He also hold 10 other diplomas and certificates in several aspects of Biotechnology and Molecular biology from reputable institutions on the continents of Africa, Asia, Europe and America. My academic career took a start as a graduate fellow in 1989 at the Obafemi Awolowo University in Nigeria, and in 1992 after obtaining his Master degree in Microbiology he was appointed Research Officer in the Biotechnology Unit of the Federal Institute of Industrial Research, Lagos, Nigeria. In 1993 he was appointed Assistant Lecturer at the Obafemi Awolowo University in Nigeria, and rose through the ranks to the post of Senior Lecturer in 2001, a post he held until I retired from the University to take up an appointment as Associate Professor of Microbiology at the University of Fort Hare, South Africa in 2006. In January 2008 he was promoted Full Professor of Microbiology in the same University, and in January 2009 he was appointed Head of the Department of Biochemistry and Microbiology to date. He have therefore garnered extensive experience not only in teaching and research but also in administration, having also served in numerous committees in the University system including the Appointment and Promotion Committee as well as elected for a two years term as President of Obafemi Awolowo University Staff Club in 2002

Abstract

Stenotrophomonas maltophilia is increasingly emerging as an opportunistic pathogen of global concern. Due to its inherent resistance to several classes of antibiotics including carbapenems and its ability to acquire moblile resitance elements, treatment of infections caused by S. maltophilia is a constant challenge for clinicians. Trimethoprim-sulphamethoxazole (TMP-SMX) is the generally accepted antibiotic of choice for the treatment of infections caused by this organism, but resistance to the drug is increasingly being reported; hence, the need for alternative therapeutic options. In this study, the antimicrobial susceptibility profile of one hundred and ten (110) commensal Stenotrophomonas maltophilia isolates obtained from Nkonkobe municipality, Eastern Cape Province was investigated. Twenty one antibiotics including trimethoprim-sulphamethoxazole and the newer fluoroquinolones; levofloxacin, gatifloxacin and moxifloxacin were included in the antibiotic panel. About 63.4% of the isolates were susceptible to trimethoprim-sulfamethoxazole with a resistance rate of 28.2%. The fluoroquinolones were more effective with susceptibilities ranging from 76% to 94.7%. Resistance to the fluoroquinolones ranged from 1.3% to 2.7%. Levofloxacin was the most effective fluoroquinolone tested. Phenotypic dectection of ESBLs showed double disc synergy test (DDST) positivity in 59.5% of the isolates. Cefepime was the most sensitive indicator cephalosporin in the DDST with 77.3% of suspected ESBL-producing isolates showing cefepime-clavulanic acid synergy. The isolates exhibited nine different ESBL phenotypes, however, PCR amplification of the bla genes revealed four isolates that possessed genes belonging to the CTX-M group (CTX-M-1 and CTX-M-8 groups). ESBL genes are usually carried on mobile elements such as plasmids and transposons which may also bear genes that mediate resistance to aminoglycosides, tetracyclines, trimethoprim-sulfamethoxazole and fluoroquinolones. ESBL positive isolates appeared more susceptible to the fluoroquinolones compared to TMP-SMX but there was no significant relationship between ESBL production and susceptibility to these drugs (p> 0.05). The newer fluoroquinolones are a possible alternative treatment option for S. maltophilia infections in this environment but further studies and clinical investigations are needed to determine the in vivo efficacy of these drugs.