Molecular characterization of CTX-M type Extended Spectrum Beta Lactamase producing E. coli isolated from humans and the environment.

PURPOSE

Escherichia coli is a common pathogen causing community- and hospital-acquired infections. The infections caused by the Extended Spectrum Beta Lactamase (ESBL) enzymes-producing E. coli hinder antibiotic treatment.

MATERIALS AND METHODS

Plasmid DNA samples were subjected to PCR specific for TEM, SHV and CTX-M genes obtained from 110 E. coli strains isolated from hospitalized patients, healthy individuals and environment in Vellore, South India .

RESULTS

Among the 110 isolates tested, 21.8% were positive for TEM and 2.7% positive for SHV and 91.8% positive for CTX-M. The proportion of CTX-M positive E. coli was not statistically different between the study groups. Nineteen of 20 strains were CTX-M-15 type and the other was CTX-M-14 type. The phylogenetic analysis of 19 strains clustered with the pandemic CTX-M-15-ST131 strain, indicating this as an evolving global problem for antibiotic therapy. The geomapping of samples indicated 'hotspot' areas of healthy individuals, patients and the environmental samples.

CONCLUSION

The spatial presentation of GIS mapping allowed identification of clustering among patients and healthy individuals and contaminated environmental points.