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Aims Carbapenem-resistant Escherichia coli has been categorized as a pathogen of critical priority by the World Health Organization as it is highly infectious with high mortality and morbidity rates and widespread transmission potential. Carbapenem resistance is primarily mediated by carbapenemase-encoding genes and, additionally, through intrinsic factors. In India, over the years, carbapenemase-encoding genes have been reported from diverse clinically significant pathogens. The present study identifies E. coli of clinical origin that harbours bla OXA-144. Methods and results The study isolate was obtained from a tertiary referral hospital in northeast India. Carbapenemase production was investigated through culture on chromogenic agar and Rapidec Carba NP test as per manufacturer's instructions. Susceptibility of the isolate was performed by the Kirby–Bauer disc diffusion method and agar dilution method following CLSI guidelines. PCR targeting carbapenemase-encoding genes was performed, followed by transformation and conjugation experiments. Whole-genome sequencing of the isolate was done through the Illumina sequencing platform and the data were analysed using the Centre for Genomic Epidemiology database. BJD_EC180 is 6 919 180 bp in length and consists of six rRNA operons, 111 tRNA, and 6849 predicted protein-coding sequences. BJD_EC180 belonged to ST2437 and harboured the carbapenemase-encoding gene bla OXA-144 with ISAba1 upstream, along with multiple antibiotic resistance genes conferring clinical resistance towards beta-lactams, aminoglycosides, amphenicols, sulphonamides, tetracyclines, trimethoprim, and rifampin. Conclusions Carbapenem-resistant E. coli harbouring bla OXA-144 associated with insertion sequence pose a serious health threat as their mobilization into carbapenem non-susceptible strains that will contribute to the resistance burden and therefore, needs urgent monitoring. [ABSTRACT FROM AUTHOR]

Background: Carbapenem-Resistant Enterobacterales (CRE) has been categorized as pathogens of critical priority by World Health organization (WHO) as they pose significant threat to global public health. Carbapenemase production considered as the principal resistance mechanism against carbapenems and with the recent surge and expansion of carbapenemases and its variants among clinically significant bacteria in India, the present study reports expansion blaOXA−78 and blaOXA−58 of in CRE of clinical origin. Methods: Bacterial isolates were collected from a tertiary referral hospital and identified through VITEK® 2 Compact automated System (Biomerieux, France). Rapidec® Carba NP (Biomerieux, France) was used to investigate carbapenemase production followed by antibiotic susceptibility testing through Kirby-Bauer Disc Diffusion method and agar dilution method. Class D carbapenemase genes were targeted through PCR assay followed by investigation of horizontal transmission of blaOXA−58 and blaOXA−78. Whole genome sequencing was carried out using Illumina platform to investigate the genetic context of blaOXA−58 and blaOXA−78 genes and further characterization of the CRE isolates. Results: The carbapenem-resistant Escherichia coli (BJD_EC456) and Serratia marcescens (BJD_SM81) received during the study from the tertiary referral hospital were isolated from sputum and blood samples respectively. PCR assay followed by whole genome sequencing revealed that the isolates co-harbor blaOXA−58 and blaOXA−78, a variant of blaOXA−51. Horizontal transfer of blaOXA−58 and blaOXA−78 genes were unsuccessful as these genes were located on the chromosome of the study isolates. Transposon Tn6080 was linked to blaOXA−78 in the upstream region while the insertion sequences ISAba26 and ISCfr1 were identified in the upstream and downstream region of blaOXA−58 gene respectively. In addition, both the isolates were co-harboring multiple antibiotic resistance genes conferring clinical resistance towards beta-lactams, aminoglycosides, fluroquinolones, sulphonamides, tetracyclines. BJD_EC180 belonged to ST2437 while BJD_SM81 was of an unknown sequence type. The nucleotide sequences of blaOXA−78 (OQ533021) and blaOXA−58 (OQ533022) have been deposited in GenBank. Conclusions: The study provides a local epidemiological information regarding carbapenem resistance aided by transposon and insertion sequences associated blaOXA−78 and blaOXA−58 genes associated and warrants continuous monitoring to prevent their further dissemination into carbapenem non-susceptible strains thereby contributing to carbapenem resistance burden which is currently a global concern. [ABSTRACT FROM AUTHOR]

Background: Foodborne illness is a global concern and identification of pathogens that cause foodborne disease is a public health priority. Serratia marcescens is an opportunistic pathogen responsible for food poisoning due to its ability to colonize the gastrointestinal surfaces. Serratia marcescens is also responsible for causing a wide range of extraintestinal infections such as pneumonia, urinary tract infection, and keratitis. Aim: The current study investigated the presence of antibiotic-resistant virulent S. marcescens from street food samples. Methods: Two pigmented S. marcescens were recovered from panipuri samples which were then identified using VITEK® GN cards. The virulence genes and the antibiotic resistance genes harbored by the S. marcescens isolates were investigated and further transformation assay was conducted to check the horizontal transferability of the plasmid carrying the antimicrobial resistance genes. Incompatibility typing of the transformants was also assessed and enterobacterial repetitive intergenic consensus polymerase chain reaction was performed to check the heterogeneity of the S. marcescens isolates. Results: Two S. marcescens isolates harboring virulence genes as well as antibiotic resistance genes were detected in this study and it was observed that Inc FIB type plasmid was carrying the resistance genes. Conclusion: The co-existence of both the virulence and antibiotic resistance genes in the two S. marcescens isolates warrants proper surveillance in order to prevent the spread of such pathogenic strains in the environment as well as the community through food samples. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Escherichia coli pose a significant threat to global public health due to the dearth of available treatment options, resulting in infections with high mortality and morbidity. The study aimed to investigate the mechanism of carbapenem resistance in a carbapenem non-susceptible E. coli isolate recovered from an urinary tract infection patient admitted to a tertiary referral hospital, through whole-genome sequencing using Illumina NovaSeq 6000 platform. Carbapenemase production followed by antibiotic susceptibility testing were performed following Clinical Laboratory Standard Institute guidelines. Polymerase chain reaction targeting carbapenemase genes was performed followed by an investigation of horizontal transferability. The Center for Genomic Epidemiology database was used to analyze the sequenced data. ST2519 E. coli BJD_EC1808 with a genome size of 5.8 Mb harbored Col440I plasmid and a chromosomally located bla OXA-116 gene with an IS18 element upstream, along with multiple antibiotic resistance genes conferring clinical resistance toward beta-lactams, aminoglycosides, amphenicols, sulfonamides, tetracyclines, trimethoprim, rifampin, macrolide, and streptogramin antibiotics and antiseptics. E. coli ST2519 harboring bla OXA-116 associated with a mobile genetic element exhibiting carbapenem resistance is a public health threat due to its limiting effect on the therapeutic usage of carbapenem and their dissemination into carbapenem non-susceptible phenotypes will contribute to carbapenem resistance burden and, therefore, warrants urgent monitoring and clinical intervention.

Acquired carbapenemases pose a significant role in the dissemination of antimicrobial-resistant Enterobacteriaceae and in this study we have identified the occurrence of bla IMP-4 in E. coli isolate from a sewage outfall located nearby a secondary health Centre. It was found to co-existed with bla CTX-M-15 located within a self-conjugable plasmid of IncF type. The current study underscores environment as a potential reservoir of carbapenem resistance and the need of the hour is to track and check dissemination of resistance in environment, human and agricultural settings., (Copyright © 2021 Indian Association of Medical Microbiologists. Published by Elsevier B.V. All rights reserved.)