Comparative Genomics of Escherichia coli Isolated from Skin and Soft Tissue and Other Extraintestinal Infections

• Published in: mBio 2017-08, Vol.8 (4)
• Main Authors: Ranjan, Amit, Shaik, Sabiha, Nandanwar, Nishant, Hussain, Arif, Tiwari, Sumeet K, Semmler, Torsten, Jadhav, Savita, Wieler, Lothar H, Alam, Munirul, Colwell, Rita R, Ahmed, Niyaz
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; beta-Lactamases - genetics; Biofilms; Drug Resistance, Multiple, Bacterial - genetics; Escherichia coli - drug effects; Escherichia coli - genetics; Escherichia coli - isolation & purification; Escherichia coli - pathogenicity; Escherichia coli Infections - microbiology; Extraintestinal Pathogenic Escherichia coli - genetics; Genes, Bacterial; Genomics; Genotype; Humans; India - epidemiology; Phenotype; Phylogeny; Pyelonephritis - microbiology; Sepsis - microbiology; Sequence Analysis, DNA; Skin - microbiology; Skin Diseases, Bacterial - microbiology; Soft Tissue Infections - microbiology; Virulence Factors
• ISSN: 2161-2129; 2150-7511
• DOI: 10.1128/mBio.01070-17

, an intestinal Gram-negative bacterium, has been shown to be associated with a variety of diseases in addition to intestinal infections, such as urinary tract infections (UTIs), meningitis in neonates, septicemia, skin and soft tissue infections (SSTIs), and colisepticemia. Thus, for nonintestinal infections, it is categorized as extraintestinal pathogenic (ExPEC). It is also an opportunistic pathogen, causing cross infections, notably as an agent of zoonotic diseases. However, comparative genomic data providing functional and genetic coordinates for ExPEC strains associated with these different types of infections have not proven conclusive. In the study reported here, ExPEC isolated from SSTIs was characterized, including virulence and drug resistance profiles, and compared with isolates from patients suffering either pyelonephritis or septicemia. Results revealed that the majority of the isolates belonged to two pathogenic phylogroups, B2 and D. Approximately 67% of the isolates were multidrug resistant (MDR), with 85% producing extended-spectrum beta-lactamase (ESBL) and 6% producing metallo-beta-lactamase (MBL). The genotype was observed in at least 70% of the isolates in each category, conferring resistance to an extended range of beta-lactam antibiotics. Whole-genome sequencing and comparative genomics of the ExPEC isolates revealed that two of the four isolates from SSTIs, NA633 and NA643, belong to pandemic sequence type ST131, whereas functional characteristics of three of the ExPEC pathotypes revealed that they had equal capabilities to form biofilm and were resistant to human serum. Overall, the isolates from a variety of ExPEC infections demonstrated similar resistomes and virulomes and did not display any disease-specific functional or genetic coordinates. Infections caused by extraintestinal pathogenic (ExPEC) are of global concern as they result in significant costs to health care facilities management. The recent emergence of a multidrug-resistant pandemic clone, ST131, is of primary concern as a global threat. In developing countries, such as India, skin and soft tissue infections (SSTIs) associated with are marginally addressed. In this study, we employed both genomic analysis and phenotypic assays to determine relationships, if any, among the ExPEC pathotypes. Similarity between antibiotic resistance and virulence profiles was observed, ST131 isolates from SSTIs were reported, and genomic similarities among strains isolated from differ