Extra-intestinal β-lactamase Producing Escherichia coli Infection-an Emerging InfectionÂ in a South Indian Tertiary Care Hospital
Department of Medicine, Kasturba Medical College,
Manipal University, Mangalore -575001
Introduction: In the recent years, extra-intestinal Escherichia coli infection has been a very important cause of mortality and morbidity. However, only a limited number of literatures are available on the clinical presentation and the outcome of the extra-intestinal pathogenic E.coli (ExPEC) infections. We investigated the prevalence, risk factors, anti-biogram and the outcome of the antibiotic treatment of the extra-intestinal infections caused by E.coli among hospitalized patients. This descriptive study was carried out in a multispeciality, tertiary care hospital.
Methods and Material: Two hundred ExPEC infected patients were included in the study. The demographic data, risk factors, details of the organ failure, anti-biogram, treatment and the outcome were collected in a structured pro forma. The severity was assessed by the APACHE II Score. The E.coli isolates were microbiologically characterized as Extended Spectrum β lactamase (ESBL) producers if they were found to be resistant to penicillin and the cephalosporins.
Statistical analysis: The proportions were expressed as percentages. The categorical data between the infection with the ESBL producers and the non-ESBL producers were compared by using the Chi-square test. The statistical analysis was performed by using SPSS, version 17.0.
Results: Out of the 200 E.coli isolates, 132(66%) were extended spectrum beta lactamase producers. Diabetes mellitus (DM) was the most important risk factor for the ExPEC infection. In the anti-biogram, a high degree of resistance was seen against ampicillin (84%), the fluoroquinolones (71%), the 3rd generation cephalosporins (66%), the sulfonamides (58.5%), and the aminoglycosides (41%). Carbapenam resistance was seen in 8% of the isolates. For the treatment, the most widely prescribed antibiotics were the β-lactam+β-lactamase inhibitor combinations (39%) and the 3rd generation cephalosporins (18.5%). 65.15% patients improved with proper treatment, 15.9% patients expired (p=0.02) and 16.5% patients relapsed. There was no correlation between the risk factors, ages of the patients, the APACHE II score, organ failure and the ESBL producers. However, an increased mortality was seen in patients with blood stream infections and lung infections which were caused by E. coli.
Conclusions: The ExPEC Infection is associated with a high level of drug resistance, mortality, morbidity and relapse. The early use of the appropriate empirical antibiotics will probably reduce the mortality and the morbidity in these patients. The 8% carbapenam resistance implies that the organisms which produce carbapenemase (superbug) also infect our patients and this may emerge as a major cause of morbidity and mortality among the patients with ExPEC in the future.