Multi-drug resistance traits of methicillin-resistant Staphylococcus aureus and other Staphylococcal species from clinical and environmental sources Adegboyega O. Oladipo, Oluwatosin G. Oladipo and Cornelius C. Bezuidenhout ABSTRACT Multi-drug resistance traits of Staphylococcus species especially methicillin-resistant Staphylococcus aureus (MRSA) in the clinical settings are well established. Of environmental concern is hospital effluents discharging into wastewaters. This article investigated the prevalence and detection of antibiotic resistance genes in Staphylococcus species from clinical and environmental sources in Ile- Ife, Nigeria. Standard culture-based and molecular protocols were used. Seventy-six (27 clinical, 14 hospital effluent and 35 environmental) Staphylococcus isolates were recovered: 56.58% were coagulase-negative and 43.42% coagulase-positive (S. aureus). For the clinical isolates, 10, 6, 4, 4 and 1 were isolated from urine, skin, wounds, blood and pus, respectively. Isolates were resistant to methicillin and amoxycillin (91.7%), cloxacillin (88.0%), ciprofloxacin (84.0%), ofloxacin (83.3%), azithromycin (78.0%), ceftazidime (76.0%), gentamycin (75.0%), cefuroxime (75.0%) and erythromycin (72.0%). Nearly, all isolates (90.8%) had multiple antibiotic resistance (MAR) index >0.2. Overall MAR indices for Staphylococcus species isolated from the clinical, hospital effluent and environmental wastewaters were relatively similar (0.482; 0.500; 0.435). mecA, nuc and luk-pvl genes were detected in S. aureus, while mecA was detected in S. arlettae, S. sciuri, S. cohnii, S. epidermidis and S. saprophyticus. This study informs on the potential contamination of environmental waters downstream from hospitals and possible impacts that this could have on human and animal health. Adegboyega O. Oladipo Oluwatosin G. Oladipo Cornelius C. Bezuidenhout (corresponding author) Unit for Environmental Sciences and Management: Microbiology, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa E-mail: carlos.bezuidenhout@nwu.ac.za Adegboyega O. Oladipo Department of Medical Microbiology and Parasitology, Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), P.M.B 5538, Ile-Ife, Nigeria Key words | antibiotic resistance genes, coagulase-negative Staphylococcus species (CoNS), hospital effluents, MRSA, receiving wastewaters, Staphylococcus species INTRODUCTION Currently in human medicine, antibiotics are the most effec- tive antimicrobials used for combatting bacterial infections. However, the uncontrolled, excessive and misuse of anti- biotics has played a key role in the selection of antibiotic- resistant bacteria (ARB) (Finley et al. ; Tripathi & Tripathi ; Jensen et al. ). Hospital effluents have been identified as a major reservoir for pollutants such as pharmaceutical wastes (antibiotics) and pathogenic microorganisms (Huang et al. ). Studies have reported that the discharge of hospital wastewaters is a highly selective route for the dissemination of ARB into natural environments (receiving water bodies) (Yilmaz et al. ; Kumar et al. ). However, the effect of antibiotics as environmental pollutants has been largely overlooked (Moges et al. ; Sabri et al. ). According to Finley et al. () and Burgmann et al. (), there are no regulations guiding the release of antibiotic residues into wastewaters from hospital effluents. It is documented 930 © IWA Publishing 2019 Journal of Water and Health | 17.6 | 2019 doi: 10.2166/wh.2019.177 Downloaded from http://iwaponline.com/jwh/article-pdf/17/6/930/637370/jwh0170930.pdf by guest on 04 June 2024