Hindawi International Journal of Microbiology Volume 2019, Article ID 2965490, 9 pages https://doi.org/10.1155/2019/2965490 Research Article Methicillin- and Inducible Clindamycin-Resistant Staphylococcus aureus among Patients with Wound Infection Attending Arba Minch Hospital, South Ethiopia Mohammedaman Mama ,1 Addis Aklilu,2 Kassahun Misgna,3 Molla Tadesse,4 and Eyerusalem Alemayehu5 1Department of Medical Laboratory Sciences, Madda Walabu University Goba Referral Hospital, Bale-Goba, Ethiopia 2Department of Medical Laboratory Sciences, Arba Minch University, Arba Minch, Ethiopia 3Black Lion Specialized Hospital, Addis Ababa University, Addis Ababa, Ethiopia 4Kebridehar Primary Hospital, Ethio-Somale, Ethiopia 5Arba Minch Hospital, Arba Minch, Ethiopia Correspondence should be addressed to Mohammedaman Mama; [email protected] Received 5 December 2018; Accepted 11 March 2019; Published 1 April 2019 Academic Editor: Barbara H. Iglewski Copyright © 2019 Mohammedaman Mama et al. *is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Wound infection is one of the most common hospital-acquired infections. Different bacteria cause infection, of which Staphylococcus aureus is one of the known bacteria in causing infection with increased drug-resistant isolates. Objective. To assess the prevalence and antimicrobial susceptibility pattern of methicillin and inducible clindamycin-resistant Staphylococcus aureus among patients with wound infections attending Arba Minch Hospital. Methods. A facility-based cross-sectional study was conducted from April to June 2017. A pretested questionnaire was used to collect demographic data and clinical characteristics. Wound swabs were cultured and identified by standard techniques. Antibiotic susceptibility tests were performed by the Kirby–Bauer disc diffusion method. Methicillin resistance was detected using the cefoxitin (30 μg) antibiotic disc while inducible clindamycin resistance was detected by the D-zone test. *e data were analyzed using Statistical Package for Social Science, version 20. p value <0.05 was considered statistically significant. Results. A total of 161 patients were enrolled and a majority of them were female (90, 50.9%). Among the collected samples, 79 (49.7%) were positive for S. aureus; of this, methicillin resistance accounted for 65 (82.3%). Out of 22 (27.8%) erythromycin-resistant isolates, 19 (24.1%) showed inducible clindamycin resistance. Methicillin-resistant S. aureus showed higher resistance against tetracycline (72.3%) followed by cotrimoxazole (43.1%) and 100% sensitivity to vancomycin. *e overall prevalence of inducible clindamycin resistance among methicillin-resistant isolates was 16 (24.6%). Conclusion. *e increasing prevalence of methicillin-resistant S. aureus and the coresistance against other therapeutic options like clindamycin is becoming an obstacle in the treatment of infections which need attention from concerned bodies. 1. Introduction aureus is a Gram-positive bacterium which is a major causative agent of different skin infections such as surgical Wound infection is one of the known hospital-acquired site infections, burns, and wounds [6, 7]. infections responsible for significant human mortality and Methicillin-resistant S. aureus (MRSA) is a highly in- morbidity worldwide [1]. Wound infection results in sepsis, fectious strain of the ordinary S. aureus bacteria that is able disfiguring, amputation, limb loss, long hospital stays, and to withstand the curative ability of commonly used anti- higher costs [2, 3]. Infections of wounds can be caused by biotics. Methicillin resistance of S. aureus is due to the different microorganisms, like Staphylococcus aureus (S. acquisition of mecA gene that encodes for penicillin-binding aureus), Pseudomonas aeruginosa (P. aeruginosa), Escher- protein 2a, which has low affinity to methicillin. Methicillin- ichia coli (E. coli), and Enterococcus [4, 5]. Staphylococcus resistant S. aureus is a serious concern not only because of 2 International Journal of Microbiology resistant to methicillin but also because of developing re- moistened sterile gauze and sterile normal saline solution. sistant to other commonly used antibiotics in the hospitals Dressed wounds were cleansed with sterile normal saline that limited therapeutic options to few expensive drugs like after removing the dressing. *e specimen was collected on vancomycin [7–9]. sterile cotton swab by rotating with sufficient pressure. *e *e increasing incidence of methicillin resistance among samples were transported to Medical Microbiology and Staphylococci has led to renewed interest in the usage of Parasitology Laboratory of Arba Minch University within macrolide-lincosamide-streptogramin B (MLSB) antibiotics thirty minutes after collection using Amies transport media. to treat S. aureus infections, with clindamycin being the preferable agent due to its excellent pharmacokinetic properties [10, 11]. However, widespread use of MLSB 2.4. Inoculation and Identification. *e collected samples antibiotics has led to an increase in the number of Staph- were immediately processed for bacteriological analysis. ylococcal strains acquiring resistance to MLSB antibiotics Swabs collected were streaked on Mannitol salt agar by using [12–14]. a swab containing the sample on one-sixth of the media and Methicillin-resistant S. aureus is found worldwide with then spread throughout the media by sterile inoculation an estimated colonization rate ranging from 11 to 40% in loop. *e plates were incubated at 37°C for 24–48 hours. specific populations with more than 50% of these estimated Preliminary identification of bacteria was based on colony to develop the infection [8, 15, 16]. Methicillin-resistant S. characteristics of the organisms like growth on Mannitol salt aureus infection kills more Americans each year than HIV/ agar, gram reaction, and catalase and slide coagulase and test AIDS, Parkinson’s disease, emphysema, and homicide tube coagulase for slide coagulase-negative test results. combined in USA [15]. Despite the advances in modern medicine, wound infection still poses a risk of increased morbidity and mortality to patients. Even though many 2.5. Detection of MRSA. Methicillin-resistant S. aureus was studies have analyzed the prevalence and antimicrobial identified phenotypically based on its resistance to oxacillin susceptibility pattern of MRSA, there is still an increasing (1 μg) and cefoxitin (30 μg) (Oxoid, Basingstoke, UK) by the prevalence of MRSA [17]. *erefore, this study was aimed to disc diffusion method performed on modified Muller- assess the prevalence and antimicrobial susceptibility pat- Hinton agar (Oxoid, Basingstoke, UK). Based on the tern of methicillin and induced clindamycin-resistant S. CLSI, 2016 guideline, the zone of inhibition is interpreted aureus among patients with wound infection attending Arba and grouped into methicillin-sensitive and methicillin- Minch Hospital. resistant S. aureus [18]. 2. Materials and Methods 2.6. Detection of Inducible Clindamycin Resistance. A lawn 2.1. Study Design, Area, and Period. A hospital-based cross- culture of the isolates adjusted to 0.5 McFarland’s turbidity sectional study was conducted at Arba Minch Hospital, from was made on a Mueller-Hinton agar plate, and discs of April to June 2017. Arba Minch Hospital in Arba Minch clindamycin (2 μg) and erythromycin (15 μg) (Oxoid, town, Gamo Gofa Zone, is situated 505 km south of Addis Basingstoke, UK) were placed at a distance of 15 mm apart as Ababa at an elevation of 1285 meters above sea level. *e per the Clinical Laboratory Standard Institute (CLSI, 2016) hospital gives service for more than 100 thousand people in recommendations, along with routine antibiotic suscepti- Arba Minch and surrounding woredas. bility testing. *is interpretation was done only for erythromycin-resistant S. aureus strains. Induction test re- sults were read at 16 to 18 h. 2.2. Sample Size Determination and Sampling Technique. D phenotype (inducible MLSB) erythromycin (ERY) *e sample size was obtained using sample size de- resistant (R), clindamycin (CLI) sensitive (S) (blunted, termination formula for the estimation of the single pop- D-shaped clear zone around CLI disk proximal to the ERY ulation proportion. p value of 0.12 for MRSA was taken from disk); D+ the previous study [10] with 95% confidence interval phenotype (inducible MLSB) ERY R, CLI S (z � 1.96) and 5% marginal error (d � 0.05). *e final sample (blunted, D-shaped zone around CLI disk proximal to the size was 180 which includes 10% nonresponse rate. Sys- ERY disk and small colonies growing to CLI disk in oth- tematic sampling technique was used to select patients with erwise clear zone); Neg phenotype (MSB) ERY R, CLI S th (clear zone around CLI disk); HD phenotype (constitutive wound infection during the study period using K interval. *e first patient was selected by the lottery method from the MLSB) ERY R, CLI R (two zones of growth appear around first three patients, and the rest of the study participants were CLI disk: one zone is light, hazy growth extending from the CLI disk to the second zone where the growth is much selected in every 3 patients. heavier; the inner, hazy zone is blunted proximal to the ERY disk as in phenotype D; R phenotype (constitutive MSB): no 2.3. Data Collection, Sample Collection, and Transportation. hazy zone, growth up to CLI