Species and drug susceptibility profiles of staphylococci isolated from healthy children in Eastern Uganda

Abstract

Staphylococci are a key component of the human microbiota, and they mainly colonize the skin and anterior nares. However, they can cause infection in hospitalized patients and healthy individuals in the community. Although majority of the Staphylococcus aureus strains are coagulase-positive, some do not produce coagulase, and the isolation of coagulase-positive non-S. aureus isolates in humans is increasingly being reported. Therefore, sound knowledge of the species and characteristics of staphylococci in a given setting is important, especially isolates from children and immunocompromised individuals. The spectrum of Staphylococcus species colonizing children in Uganda is poorly understood; here, we aimed to determine the species and characteristics of staphylococci isolated from children in Eastern Uganda. Seven hundred and sixty four healthy children less than 5 years residing in Iganga and Mayuge districts in Eastern Uganda were enrolled. A total of 513 staphylococci belonging to 13 species were isolated from 485 children (63.5%, 485/764), with S. aureus being the dominant species (37.6%, 193/513) followed by S. epidermidis (25.5%, 131/513), S. haemolyticus (2.3%, 12/513), S. hominis (0.8%, 4/513) and S. haemolyticus/lugdunensis (0.58%, 3/513). Twenty four (4.95%, 24/485) children were co-colonized by two or more Staphylococcus species. With the exception of penicillin, antimicrobial resistance (AMR) rates were low; all isolates were susceptible to vancomycin, teicoplanin, linezolid and daptomycin. The prevalence of methicillin resistance was 23.8% (122/513) and it was highest in S. haemolyticus (66.7%, 8/12) followed by S. aureus (28.5%, 55/193) and S. epidermidis (23.7%, 31/131). The prevalence of multidrug resistance was 20.3% (104/513), and 59% (72/122) of methicillin resistant staphylococci were multidrug resistant. Four methicillin susceptible S. aureus isolates and a methicillin resistant S. scuiri isolate were mupirocin resistant (high-level). The most frequent AMR genes were mecA, vanA, ant(4’)-Ia, and aac(6’)-Ie- aph(2’’)-Ia, pointing to presence of AMR drivers in the community.