Supplementary Material for: Detection of Antibiotic Resistance Determinants and Their Transmissibility among Clinically Isolated Carbapenem-Resistant <b><i>Escherichia coli</i></b> from South India

<b><i>Objectives:</i></b> The aim of this study was to analyze the prevalence of the CTX-M, TEM, SHV, VIM, NDM, and OXA genes in carbapenemase-producing <i>Escherichia coli</i> and their transmissibility at a tertiary care hospital in south India. <b><i>Materials and Methods:</i></b> Twenty-one carbapenem-resistant <i>E. coli</i> (carbapenem-resistant Enterobacteriaceae; CRE) were collected from the Sri Sathya Sai Institute of Higher Medical Sciences (Puttaparthi India). Resistance to antibiotics was analyzed by Vitek-2, and the identity of the isolates was confirmed by 16S rDNA sequencing. RAPD and enterobacterial repetitive intergenic consensus (ERIC)-PCR were performed for molecular typing. Metallo-β-lactamase production was confirmed by a double disc synergy test. The presence of the extended-spectrum β-lactamases CTX-M, TEM, and SHV and of the carbapenemases NDM, VIM, and OXA was determined by PCR. Carbapenemase variants were further confirmed by sequencing. The transmissibility of the genes was tested by conjugation. <b><i>Results:</i></b> Twelve of the 21 (57%) carbapenem-resistant <i>E. coli</i> isolates were community acquired, indicating the spread of CRE in environmental samples. TEM and NDM-5 were found to be the major β-lactamases produced by the pathogens. OXA-181 was found in 5 of the isolates. All 21 isolates were found to harbor more than one of the tested β-lactamases, and all of the isolates were found to have the capacity to participate in conjugation; 15 of the transconjugants were found to have acquired the tested β-lactamases, substantiating their ability to be transferred to other strains of bacteria. <b><i>Conclusion:</i></b> Monitoring of community-acquired carbapenem-resistant bacteria is very important as the association of resistance determinants with mobile genetic elements would present a serious clinical challenge.