Antibiotic resistance pattern among biofilm producing and non producing Proteus strains isolated from hospitalized patients; Matter of hospital hygiene and antimicrobial stewardship

Abstract

A retrospective study on antimicrobial susceptibility and biofilm production were carried out for eighty eight strains of Proteus strains isolated from UTI and other hospital samples during April 2011-April 2012. The antibiotic susceptibility was carried out by Kirby-Bauer disk diffusion and MIC by E-test. Biofilm production was measured by microliter method and confirmed by Scanning electron microscopy. Plasmids from biofilm producing isolates were detected by alkaline lysis technique. From 88 patients infected by proteus species, 58% were female and 42% were mail. The most frequent age range was 20-29 (77.39%) and the least were 60-69 years old (3.4%) (p = 0.05). Eighty one isolates were identified as P. mirabilis while, 7 identified as P. vulgaris. 61.04% [n = 59] of the isolates showedMIC range (16-32+0.05 ugrnL1) to ceftriaxone, 46.59% [n= 41] exhibited least MIC range to chloramphenicol (8-64±0.08 ug mL1). 31% [n= 28] of the isolates also exhibited MIC range 1 -4 ug mL-1 to ciprofloxacin. 17% [n = 15] of the isolates exhibited strong biofilm while, 6% [n = 6] did not show any biofilm (p<0.05). Plasmid isolation from biofilm producing isolates revealed that stains number 19, 24 and 87' that produced strong biofilm carried similar high M. Wt. plasmid. From above results it can be concluded that the majority of Proteus isolated from UTI patients were belong to P. mirabilis. Ciprofloxacin was the most effective antibiotic for treatment of the infected patients. Limited number of the isolates could produce strong biofilm that were bearing plasmids. Majority of the biofilm producing isolates were also resistance at least to 4 antibiotics routinely prescribed in our hospital. © 2013 Asian Network for Scientific Information.