Distribution and antibiogram of Staphylococci from pigs and contact humans in Abia State

Abstract

Staphylococcus species are among the dominant groups of saprophytic bacteria; however, lately, they are globally known for being opportunistic pathogens and prime cause of community-associated and hospital-acquired infections in humans and animals. This study was conducted to determine the phenotypic characteristics of Staphylococcus isolated from pigs and in-contact humans in Abia Central Senatorial Zone, Nigeria. Using standard microbiological methods 1084 nasal swab samples were collected from 968 pigs and 116 in-contact humans. Kirby-Bauer's disc diffusion method was used to determine the antibiogram of the isolates, and the findings were interpreted using CLSI interpretive values. Staphylococcus species were recovered from 38 (3.9%) of the 968 pigs screened and 2 (1.7%) of the 116 humans. The recovered species distributions were S. aureus (1), S. intermedius (10), S. hyicus (21), S. chromogens (1), S. haemolyticus (5), S. warneri (1) and S. xylosus (1). Most of the isolates were resistant to at least one antimicrobial agent. Resistance to ampicillin in 33(86.8%) of the isolates while 31(81.6%), 30(78.9%), 24(63.2%) and 23(60.5%) were resistant to vancomycin, oxacillin, penicillin and tetracycline, respectively. Thirty one unique resistance patterns were identified among the staphylococci isolates. The multiple antibiotics resistance index (MARI) for all the isolates was greater than 0.2 indicating that the isolates may have originated from an environment where antibiotics were frequently used. All the staphylococcal isolates that were resistant to vancomycin by disc