Genetic Determinants of Antibiotic Resistance in Hospital and Community Isolates of Klebsiella pneumoniae and Escherichia coli

Background: Multi-drug resistant Escherichia coli and Klebsiella pneumoniae with various resistance determinants are a major concern in hospital and community acquired infections around the world. Objectives: To describe the presence of bla(CTX-M), bla(TEM), bla(PER), bla(VEB), and integrons class 1, 2, 3 and extended spectrum beta lactamase (ESBL) phenotype in E. coli and K. pneumoniae isolates from clinical samples of inpatients and outpatients. Methods: One hundred and eighty six E. coli and fifty-eight K. pneumoniae were collected. Antimicrobial susceptibility test was performed by disk diffusion method. Extended-spectrum beta-lactamase phenotype were screened by phenotypic confirmatory test. PCR assay was performed for bla(TEM), bla(CTX-M), bla(PER) and bla(VEB) and class 1, 2, 3 integrase genes. Statistical analysis was performed by chi-squared test. Results: Extended-spectrum beta-lactamase phenotype was detected in 49 (26.3%) E. coli and 19 (32.8%) K. pneumoniae isolates. Bla(VEB) gene in 32 (17.2%) E. coli and 5 (8.6%) K. pneumoniae isolates. Bla(PER) gene in 4 (2.1%) E. coli and 0 (0%) K. pneumoniae isolates. Bla(CTX-M) gene in 113 (60.7%) E. coli and 34 (58.6%) K. pneumoniae isolates. Bla(TEM) gene in 106 (57%) E. coli and 25 (43.1%) K. pneumoniae isolates. One hundred and nine (58.6%) of E. coli and 33 (56.9%) of K. pneumoniae were carrying Class 1 integron and 18 (9.7%) of E. coli and 3 (5.2%) of K. pneumoniae were carrying Class 2 integron. Class 3 integron was not detected. Conclusions: High prevalence of ESBLs in E. coli and K. pneumoniae isolated from the community and hospital acquired infections could lead to the wide spread of multi-drug resistance clones that also contain new mechanism of resistance.