Background: Escherichia coli (E. coli) is the most common enteric organism causing extra-intestinal infections in man, particularly of urinary tract infection.
Objective: To find out the incidence of haemolytic E. coli among different clinical samples and to study their antibiogram.
Methods: All the 23,007 specimens submitted in the department of Microbiology for culture and sensitivity testing were subjected to study. The samples were processed on MacConkey agar and blood agar by conventional methods. Haemolytic E. coli were identified on the basis of colony morphology and confirmed by their biochemical characters. These haemolytic strains were further subjected to antibiotic sensitivity by Kirby-Bauer disc diffusion technique.
Results: Out of 23,007 samples, 6,209 bacterial isolates were obtained. Of these, 2,001 were identified as E. coli. Amongst these, 205 strains were haemolytic. In urine, the most frequently processed sample, 46.85% of the isolates were E. coli. Out of these, 13.97% were haemolytic E. coli. The incidence of these strains were found to be 10.10%, 4.29%, 1.68%, and 1.36% from other samples viz vaginal/cervical discharge, faeces, pus and others respectively. A total of 85 (80.18%) haemolytic E.coli strains were isolated from females of age group 21 to 40 years. Marked resistance to ampicillin (84.39%), co-trimoxazole (76.09%) and nalidixic acid (53.65%) was observed among these strains.
Conclusion: Haemolytic E. coli showed a considerable degree of multiple drug resistance. These organisms are endowed with extra virulence factor, so there is need to have greater awareness to this effect and such cases should be treated more energetically.