Phenotypic characterization of Methicillin-resistant Staphylococci isolated from wounds and nasal swabs in selected hospitals across some Northwestern States, Nigeria

Abstract

Methicillin-resistant Staphylococci (MRS) remain important opportunistic pathogens most frequently identified worldwide. The study aimed to determine the phenotypic characteristics of Methicillin-resistant Staphylococci, their antibiotic susceptibility patterns, and the sociodemographic characteristics of the isolates from wounds and nasal swabs in selected hospitals across some states in Northwestern Nigeria. A total of 806 wounds and nasal swabs were collected from patients admitted at nine facilities in 4 states of Northwestern Nigeria. All samples underwent analysis using standard bacteriological techniques. Antibiotic susceptibility testing (AST) was conducted using the Kirby-Bauer technique. Out of 806 samples, 652 (80.3%) were culture positive, while 154 (19.1%) were culture negative. A total of 704 (87.3%) isolates were obtained, out of which 418 (59.4%) were identified as Staphylococci isolates, comprising 144 (17.7%) Methicillin-resistant Staphylococcus aureus (MRSA), 124 (15.4%) Methicillin-susceptible Staphylococcus aureus (MSSA), 89 (11%) Methicillin-resistant coagulase-negative Staphylococci (MRCoNS), and 61 (7.6%) Methicillin susceptible coagulase-negative Staphylococci (MSCoNS). The Staphylococci isolates showed the highest susceptibility to Vancomycin 408 (97.6%), while the lowest was penicillin 24 (5.7%). The isolation rate of MRS was highest among patients aged 11-30, while the 71-90 age group had the lowest rate. The occurrence was higher (37%) in male patients than in female patients (18.6%). Moreover, there was no statistically significant association found between the distribution of MRS among different age groups, gender, and occupational affiliations, but it exists in the educational levels, and economic statuses of the research participants. The occurrence of MRS was lower among patients with a high level of formal education but higher among those without or with a low level of education. These findings will aid healthcare workers in establishing policies for antibiotic usage, surveillance, and infection prevention and control measures.