RISK FACTORS FOR METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS COLONIZATION IN DONKEYS AND HUMAN CONTACTS IN EBONYI STATE

Abstract

Antimicrobial resistance has now become a world-wide problem. Methicillin-resistant Staphylococcus aureus which emerged as a hospital problem in the 1960's has spread from hospitals to the community and to livestock. Livestock-associated MRSA poses an occupational risk to abattoir workers and could lead to an increase in community-associated MRSA. Prevalence of MRSA at the animal-human interface has not been widely documented in Nigeria despite the evidence of the organism posing serious public health concern. The objective of this study was to determine the prevalence of MRSA colonizing donkeys for slaughter in Ehonyi State and the prevalence of MRSA in the humans in contact with them as well as the risk factors for colonization in the human subjects. A cross sectional study was conducted over a period of six months, in Ohaukwu Local Government Area of Ebonyi State. Selection was purposive. One hundred and ninety five donkeys were sampled using a cluster sampling technique. Fifty slaughter slab workers were also sampled using convenience sampling method. Nasal swabs were obtained and cultured to identify Staphylococcal organisms. Isolates that were resistant to cefoxitin on Mueller-Hinton agar were identified as methicillin-resistant Staphylococcus aureus. Antibiotic sensitivity tests using Kirby-Bauer disc diffusion method was carried out on the MRSA positive isolates to determine their resistance profiles. Interviewer administered questionnaires was used to obtain data on risk factors from the human subjects. Data was analyzed using descriptive statistics such as means, standard deviation and proportions as well as chi square test. The criterion for statistical significance wasp< 0.05. Four breeds were identified (Idabari, Fari, Duni and Auraki). Idabari was dominant at the slab 116 (59.5%). More jennies (female donkeys) 144 (73.9%) were slaughtered than jacks (male donkeys) 51 (26.2%). The prevalence of MRSA in donkeys meant for slaughter was 79.5%. Breed and sex were not significantly associated with MRSA colonization in donkeys ( x2 = 0.150, P = 0.698, x2 = 1.136, P = 0.286). The mean age of slaughter slab workers was 32.4 ± 9.7 years. Seventy-two percent were females. Eighty-four percent were also were married. Mean number of years of work at slaughter slab was 7.6 ± 6.6 years. Eighty-two percent did not use any personal protective equipment while at work. The prevalence of MRSA in donkeys was 79.49%. The prevalence of MRSA slaughter slab workers was 54%. None of the risk factors analyzed showed significant association. All donkey MRSA isolates were multidrug- resistant (100% to ampicillin, bacitracin, oxacillin and cefoxitin; 99% cloxacillin, and mupirocin; 96% vancomycin). Susceptibility to gentamicin was 96%. Drug resistance cut across antibacterial classes; both donkey and human isolated showed resistance to vancomycin but susceptibility to gentamicin. The study identified high prevalence of MRSA colonization in donkeys and human contacts and high resistance of donkey MRSA to antimicrobials drugs that are not routinely used in donkeys. Molecular characterization of MRSA at donkey-human interface is recommended in order to understand the direction of spread of MRSA at this interface.