Antimicrobial Resistance and Virulence Genes of Invasive from Children with Bacteremia in North-central Nigeria

Objectives: Bacteremia due to invasive has been reported earlier in children in Nigeria. This study aimed to detect the virulence and antibiotic resistance genes of invasive from children with bacteremia in north-central Nigeria.

Method: From June 2015 to June 2018, 4163 blood cultures yielded 83 isolates. This is a secondary cross-sectional analysis of the isolates. The were isolated and identified using standard bacteriology protocol. Biochemical identifications of the were made by Phoenix MD 50 identification system. Further identification and confirmation were done with polyvalent antisera O and A gene. Antimicrobial susceptibility testing was done following clinical and laboratory standard institute guidelines. Resistant genes and virulence genes were determined using a real-time polymerase chain reaction.

Result: 51 (61.4%) was the most prevalent serovar, followed by species 13 (15.7%), 8 (9.6%), 6 (7.2%), and 5 (6.1%). Fifty-one (61.4%) of 83 were typhoidal, while 32 (38.6%) were not. Sixty-five (78.3%) of the 83 isolates were resistant to ampicillin and trimethoprim-sulfamethoxazole, followed by chloramphenicol 39 (46.7%), tetracycline 41 (41.4%), piperacillin 33 (33.9%), amoxicillin-clavulanate, and streptomycin 21 (25.3%), while cephalothin was 19 (22.9%). Thirty-nine (46.9%) of the 83 isolates were multi-drug resistant, and none were extensive drug resistant or pan-drug resistant. A 42 (50.6%), R 32 (38.6%), A 24 (28.9%), B 20 (20.1%), A 10 (10.0%), and G 5 (6.0%) were the antibiotic resistance genes detected. There were perfect agreement between phenotypic and genotypic detection of antimicrobial resistance in tetracycline, ciprofloxacin, and chloramphenicol, while beta-lactam showed κ = 0.60 agreement. All of the isolates had the virulence genes A, B, C, and 4D, while 33 (39.8%), 45 (51.8%), and 2 (2.4%) had Q, C, and GI-1, respectively.

Conclusion: Our findings showed multi-drug resistant in children with bacteremia in northern Nigeria. In addition, significant virulence and antimicrobial resistance genes were found in invasive in northern Nigeria. Thus, our study emphasizes the need to monitor antimicrobial resistance in from invasive sources in Nigeria and supports antibiotic prudence.