Nasopharyngeal carriage, spa types and antibiotic susceptibility profiles of Staphylococcus aureus from healthy children less than 5 years in Eastern Uganda

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.

Bacterial Tonsillitis and Antimicrobial Resistance Profiles Among Children Within Five Years of Age At Hargeisa Group of Hospital, Somaliland: A Cross-Sectional Study

“…The percentage of S. pyogenes resistant to gentamicin (42.3%) and o oxacin (43.6%) in the present study was comparable to studies done in Iran (32.2%) [44]. The resistance of Streptococcus pyogenes to the above drugs might be due to the enzymatic inactivation mediated by aminoglycoside-modifying enzymes (AMEs), and point mutations in the quinolones resistance-determining region (QRDR).…”

Assessment of Door Handles as Potential Reservoirs of Multidrug Resistant Staphylococcus aureus in Rivers State, Nigeria

“…MDR S. aureus has however been linked with a worse prognosis, increased hospital stay and mortality. Nasal carriage of MDR strains of S. aureus has however been widely reported in apparently healthy individuals (Arali et al, 2016;Kadariya et al, 2019;Kateete et al, 2019;Onanuga et al, 2021). Considering the key role door handles play as fomites, there therefore exists the potential that they play a role as possible reservoirs of MDR S. aureus.…”

Antibiotic resistance profiles and population structure of disease-associated Staphylococcus aureus infecting patients in Fort Portal Regional Referral Hospital, Western Uganda

“…Investigation into the genetic basis of antibiotic resistance and the molecular epidemiology of antibiotic resistant bacteria is needed to gain a deeper understanding of the drivers of resistance spread. PCR-based assays have been used to explore of presence/absence of AMR-and virulence-associated genes among Ugandan S. aureus isolates [9,13,19], while spa (and SCCmec for MRSA) typing has been used to provide an epidemiological context [9,10,13,[19][20][21]. These tools, however, have limited sensitivity; meanwhile advancements in rapid and affordable DNA sequencing technologies, and concurrent improvements of tools to predict AMR in silico, have led to improvements in diagnostic microbiology and studies of AMR [22].…”