Abstract:

Objective: We investigated the expression of Extended Spectrum β-Lactamases (ESBLs), AmpC β lactamases and Carbapenemases in extraintestinal pathogenic Escherichia coli (ExPEC) isolates and correlated with treatment and outcome of the patients. Methods: Three hundred ExPEC infected patients were included in the study. Demographic data, antibiogram, treatment and outcome were collected. Production of ESBLs was detected by combination disk method; AmpC was detected by AmpC disk test. Carbapenemase production was detected by disk diffusion and confirmed by modified Hodge test. Identification of metallo- β-lactamase (MBL) activity was performed by the carbapenem-EDTA combined disk method and MBL E-test. Results: Out of 300 E. coli isolates, 212 (71%) were ESBL producers. AmpC β lactamase production was seen in 95 (32%) isolates; 16 (17%) isolates were pure AmpC producers whereas 79 (83%) were ESBL co-producers. Twenty nine (9.5%) isolates were carbapenemase producers of which 15 (5%) were MBL producers. For treatment, most widely prescribed antibiotics were β-lactam+β-lactamase inhibitor combinations (39%). Sixty seven percent patients improved; relapse/re-infection was seen in 18% of patients and 11% patients expired. Increased mortality was seen in patients with blood stream infection and more number of relapses was seen in urinary tract infection. Conclusion: ExPEC producing ESBL or AmpC along with carbapenemases are particularly challenging for clinicians and are a major threat worldwide. Early use of appropriate antibiotics like β-lactam+β-lactamase inhibitor combinations will probably reduce complications in these patients.

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