Antimicrobial Resistance Patterns and Molecular Characterization of Klebsiella pneumoniae in Clinical Isolates at Mbarara Regional Referral Hospital

Abstract

Background: Klebsiella pneumoniae is one of the most frequent opportunistic pathogens causing a range of infections and being resistant for beta-lactamases (ESBL) and Carbapenemases. Aim: The aim of the present study was to determine the antimicrobial resistance patterns and molecular characterization establishing the phenotypes and genotypes associated with drug resistance, an antibiogram of genotypically positive isolates for resistance of Klebsiella pneumoniae in clinical isolates at MRRH. Materials and Methods: A laboratory-based descriptive cross-sectional study that was conducted from September 2018 to May 2019 at MRRH. Klebsiella pneumoniae was identified by cultural and biochemical methods. Antibiotic sensitivity test was performed by modified Kirby-Bauer disc diffusion technique. ESBL production in Klebsiella pneumoniae was tested by double-disc synergy test, Carbapenemase production by MHT, Boronic Acid or EDTA test using Meropenem phenotypically and both resistance confirmed genotypically by Multiplex PCR. Results: Out of 1055 clinical isolates, 298 (28.2%) were found positive for Klebsiella.spp, 175 isolates were subcultured among which 22 (12.57%) were K. pneumoniae based on API 20E. Overall Sensitivity patterns of these Klebsiella pneumoniae isolates to Ceftriaxone, (Amoxicillin/Clavulanate), Gentamicin, Cefepime, Ciprofloxacin, Cefoxitin, Nitrofurantoin, Cefuroxime, piperacillin/tazobactam, Meropenem, Ceftazidime and cefotaxime were 72.7%, 63.7%, 54.5%, 45.5%, 31.8%, 31.8%, 27.3%, 27.3%, 22.7%, 22.7%, 18.2%, 9.1%, 9.1% respectively. ESBL producing K. pneumoniae was found at 68.18% (15/22) phenotypically. Genotypically; the ESBL genes were blaCTX-M (100%), blaSHV (80%) and blaTEM (100; 47%); 8/15 (73.3%) had CTX-M, SHV, TEM, 4/15 (26.67%) CTX-M, TEM, 3/15 (20.00%) CTX-M and SHV. Carbapenemase producing K. pneumoniae was found at 31.82% (7/22) phenotypically; 1/7 (14.28%) by MHT, 4/7 (57.14%) Boronic acid test and 2/7 (28.58%) EDTA test. Genotypically; 3/4 [(75%) 42.86%] had OXA-48, 1/4 [(25%) 14.28%] OXA-48 and KPC gene, 1/2 [(50%) 14.28%] KPC and VIM, 1/2 [(50%) 14.28%] KPC and KPC gene [(100%) 14.28%]. Conclusion/Recommendations: DDS to be used for ESBL production, MHT, Boronic Acid test and EDTA tests using Meropenem/or Imipenem for Carbapenemase-production routinely.