ABSTRACT
Introduction: Healthcare associated infections(HAI) bymulti-drug resistant organisms(MDRO) are major cause ofmortality and morbidity having significant impact on qualityof life and economic burden. HAI by carbapenem-resistantPseudomonas aeruginosa (CRPsA) and Acinetobacterbaumannii (CRAB) are emerging threat for their highantibiotic resistance and spread via mobile genetic elements.Objectives of this study were to detect prevalence of CRPsAand CRAB infections in a tertiary care hospital of EasternIndia and to determine their antimicrobial resistance profile.Material and methods: This observational study was done inDepartment of Microbiology from January 2018-June 2019.From HAI patients, different clinical samples were collected.Culture and identification by standard conventional methodsand antimicrobial susceptibility tests by modified KirbyBauer disc-diffusion method following CLSI guidelines wereperformed. CRPsA and CRAB cases were identified whenisolates were resistant to ≥1 carbapenem, 10µg imipenemdisc(zone diameter ≤15mm for P. aeruginosa or ≤18mm forA. baumanii) or meropenem disc (≤15mm for P. aeruginosa or≤14mm for A. baumanii).Result: From 27,043 clinical samples, 1785(6.6%)Acinetobacter baumannii and 777(2.87%) Pseudomonasaeruginosa were isolated. CRAB and CRPsA prevalencewere 74.17% and 62.29% respectively. Carbapenemresistance were further categorised into imipenem-resistantmeropenem-resistant (IRMR) (A. baumanii-63.19%, P.aeruginosa-51.61%), imipenem-resistant-meropenemsensitive (IRMS) (A. baumanii-10.48%, P. aeruginosa-9.13%), meropenem-resistant-imipenem-sensitive (MRIS)(A. baumanii -0.51%, P. aeruginosa -1.54%) phenotypes.Fourth category was imipenem-sensitive-meropenemsensitive (ISMS) (A. baumanii -25.82%, P. aeruginosa-37.71%). Carbapenem-resistant groups showed significantlyhigh resistance for all antibiotics excepting colistin.Conclusion: Carbapenems are often used for treatingMDRO. But high carbapenem-resistance in HAI is alarming,warranting judicious use of antibiotics.
ABSTRACT
Background and objective: Multidrug-resistant Acinetobacter baumannii has one of the most serious nosocomially acquired gram negative infection in Intensive Care Unit (ICU). The gradual increase in incidence of this pathogen reflects their de-novo selection due to antibiotic usages and its ability to spread between patients. This study was undertaken to detect resistance to carbapenems in clinical isolates of A.baumannii in our ICU set up and to assess the rate of carbapenemase and MBL production among the isolates with the therapeutic options available against them. Material and methods: A.baumannii was identified by conventional methodology and susceptibility profile was determined by disc diffusion method. Carbapenem resistant isolates were further checked for mettalo beta lactamases (MBL) assay by EDTA disc synergy test and Minimum inhibitory concentration determination by agar dilution method. Results: 71.87% (n=46) of isolates showed resistance to Imipenem by disc diffusion method. 82.6% (n=38) of isolates were MBL producer both by phenotypic EDTA disc synergy test and MIC determination test by agar dilution method. The susceptibility profiles of A.baumannii strains towards colistin, polymyxinB and tigecycline were 90.62%, 57.81% and 78.12% respectively.Conclusion: Detection as well as awareness of this MBL producing A.baumannii in a hospital set up, coupled with judicious antimicrobial therapy based on sensitivity profiles will help us fight against this deadly menace.