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.
ABSTRACT
Background: Nonfermentative gram-negative bacilli (NFGB) have emerged as a major cause of nosocomial infections.This study was undertaken to know the prevalence of nonfermenters isolated from different clinical samples along with their susceptibility profile. Material and methods: Conventional bacteriological methods were used for identification and susceptibility testing of nonfermenters. Susceptibility testing was performed by methods as recommended by Clinical Laboratory Standard Institute (CLSI). Results: Out of the total 1,650 clinical samples received NFGB were found in 201 samples with an isolation rate of 12.18%. Nonfermenters isolated were Pseudomonas aeruginosa (50.24%), Acinetobacter baumannii (24.87%), Acinetobacter lowffii (5.47%), Pseudomonas fluorescens (1.49%), Pseudomonas stutzeri (1.99%), Burkholderia cepacia (6.96%), Stenotrophomonas maltophilia (2.98%), Achromobacter xylosoxidan (3.98%) and Shewanella putrefaciens (1.99%). Most of the isolated organisms were multidrugresistant (MDR). P. aerurginosa showed good sensitivity to imipenem (91.08%), cefoperazone sulbactum (68.31%) combination, amikacin (69.30%) and colistin (100%). A. baumannii showed 90% sensitivity to imipenem and 94% to colistin. Conclusion: Our study showed that prevalence of NFGB amongst different clinical isolates is significantly high especially in this part of the world and these organisms are often MDR. In this scenario, we propose all laboratory samples should be screened for NFGB even in clinically unsuspected cases. P. aeruginosa showed good sensitivity to colistin, imipenem, amikacin and cefoperazone sulbactum combination while A. baumannii showed good sensitivity to imipenem and colistin.