Abstract
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Abstract; Background:; Staphylococcus aureus carriage is a known risk factor for staphylococcal disease. However, the carriage rates vary by country, demographic group and profession. This study aimed to determine the S. aureus carriage rate in children in Eastern Uganda, and identify S. aureus lineages that cause infection in Uganda.; ; Methods:; Nasopharyngeal samples from 742 healthy children less than 5 years residing in the Iganga/Mayuge Health & Demographic Surveillance Site in Eastern Uganda were processed for isolation of S. aureus. Antibiotic susceptibility testing based on minimum inhibitory concentrations (MICs) was determined by the BD PhoenixTM system. Genotyping was performed by spa typing.; ; Results:; The processed samples yielded 144 S. aureus isolates (one per child) therefore, the S. aureus carriage rate in children was 19.4% (144/742). Thirty one percent (45/144) of the isolates were methicillin resistant (MRSA) yielding a carriage rate of 6.1% (45/742). All isolates were susceptible to rifampicin, vancomycin and linezolid. Moreover, all MRSA were susceptible to vancomycin, linezolid and clindamycin. Compared to methicillin susceptible S. aureus (MSSA) isolates (68.8%, 99/144), MRSA isolates were more resistant to non-beta-lactam antimicrobials –trimethoprim/sulfamethoxazole 73.3% (33/45) vs. 27.3% (27/99) [P<0.0001]; erythromycin 75.6% (34/45) vs. 24.2% (24/99) [P<0.0001]; chloramphenicol 60% (27/45) vs. 19.2% (19/99) [P<0.0001]; gentamicin 55.6% (25/45) vs. 25.3% (25/99) [P=0.0004]; and ciprofloxacin 35.6% (16/45) vs. 2% (2/99) [P<0.0001]. Furthermore, 42 MRSA (93.3%) were multidrug resistant (MDR) and one exhibited high-level resistance to mupirocin. Overall, 61 MSSA (61.6%) were MDR, including three mupirocin and clindamycin resistant isolates. Seven spa types were detected in MRSA, of which t037 & t064 were predominant and associated with SCCmec types I & IV, respectively. Fourteen spa types were detected in MSSA, of which t645 & t4353 were predominant.; ; Conclusions:; S. aureus carriage rate in healthy children in Eastern Uganda is high and comparable to rates for hospitalized patients in Kampala. The detection of mupirocin resistance is worrying as it could rapidly increase if mupirocin is administered in a low-income setting. S. aureus strains of spa types t064, t037 (MRSA) and t645, t4353 (MSSA) are prevalent and could be responsible for majority of staphylococcal infections in Uganda.