Journal of Pure and Applied MicrobiologyVol. 3 No. 2

Study of Virulence Markers of E. coli Isolated from U.T.I.

Suvarna Joshi¹, Yagnesh Thakar²* and Ashok Gomashe¹

¹Shri Shivaji Science College, Congress nagar, Nagpur, India. ²Vishakha Clinical Microbiology Laboratory, 612, A-wing, Lokmat Bhawan, Wardha Road, Nagpur - 440 012, India.

Received on 05 March 2009 and accepted on 18 April 2009

 

ABSTRACT

A total of 40 urinary isolates of E.coli from patients of U.T.I. and 30 faecal isolates from healthy persons were studied for O serotyping; Haemolysin production; Haemagglutination; Congo red binding. Haemolysin was positive in 21 (52.5%) of urinary isolates as against only 9 (30%) of faecal isolates; Haemagglutination was positive in 23 (57.5 %) of which 18(45%) were mannose resistant Haemagglutinating while only 10 (33.3%) of faecal isolates were Haemagglutinating. All the 40 (100%) Urinary isolates and as many as 28(93.3%) out of 30 faecal E.coli were able to bind Congo red dye. O serotyping was possible in 65% of uropathogenic and 63.3% faecal E.coli strains. The early serogroups viz; O2; O4; O8; O23; O25 were commonest. Urinary isolates of E.coli were sensitive most to Nitrofurantoin (97.5%), followed by Amikacin (95%), Gentamicin (82.5%), Ceftazidime (82.5%) and Amoxycillin+Clavulanic acid (75%), while the sensitivity was even less than 50% to Cephotaxime (47.5%), Ceftriaxone (45%), Cefuroxime (37.5%), Cefixime (25%), Ciprofloxacin (22.5%), Cotrimoxazole (17.5 %), Norfloxacin (17.5%), Ampicillin (12.5%). Thus study shows haemolysin and haemagglutination are reliable markers of virulence in uropathogenic E.coli. Congo red binding is not good marker and there is prevalence of limited serogroups of uropathogenic E.coli in this region and the isolates are generally multidrug resistant.

Keywords : Uropathogenic E. coli, Urinary tract infections, Haemagglutination, Haemolysin, Congo red binding.