AcrAB-TolC efflux pump system plays a role in carbapenem non-susceptibility in Escherichia coli

Abstract

Background Efflux pump mediated antibiotic resistance is an unnoticed and undetected mechanism in clinical microbiology laboratory. RND efflux systems are known for aminoglycoside and tetracycline resistance whereas their role in carbapenem non-susceptibility is not established. The study was undertaken to investigate the role of efflux pump in providing resistance against carbapenems and their response against concentration gradient carbapenem stress on the transcriptional level of the AcrAB gene in the clinical isolates of Escherichia coli from a tertiary referral hospital of Northeast India. Results Out of 298 non-susceptible Escherichia coli isolates 98 isolates were found to have efflux pump mediated carbapenem non-susceptibility. Among them thirty-five were non carbapenemase producers and their expressional levels were verified using qRT-PCR under concentration gradient carbapenem stress. In this study, a strong correlation between ertapenem resistance and AcrA overexpression was observed which has not been reported previously. Further, it was observed that imipenem stress increased AcrB expression in Escherichia coli which holds the novelty of this study. Additionally, the transcription of AcrR was insistently increased which is much higher than the transcriptional level of AcrA under concentration gradient carbapenem stress condition. Conclusion The study established that AcrAB pump is a relevant antibiotic resistance determinant in bacterial pathogen, has an important role in developing resistance against carbapenem group of antibiotics. Electronic supplementary material The online version of this article (10.1186/s12866-019-1589-1) contains supplementary material, which is available to authorized users.

Mapping the Role of AcrAB-TolC Efflux Pumps in the Evolution of Antibiotic Resistance Reveals Near-MIC Treatments Facilitate Resistance Acquisition

“…S2 in the supplemental material), which may be due to induction of efflux pump expression in the WT strain in the presence of chloramphenicol. Prior studies have shown that the presence of stress can increase pump expression by 4-fold ( 40 , 43 ), which is comparable to the impact of deleting acrR ( 40 – 42 ). We found that treatment with high concentrations of chloramphenicol repressed bacterial growth for multiple days.…”

Antimicrobial resistance and gene regulation in Enteroaggregative Escherichia coli from Egyptian children with diarrhoea: Similarities and differences

“…Interestingly, E36 was one of the few isolates resistant to the carbapenem antibiotics, imipenem and meropenem, ( Table 1 and S1), and yet we did not detect any obvious carbapenem resistance genes in its genome. As carbapenem resistance can be due to a variety of mechanisms [ 90 , 91 ], it is possible that we failed to detect such genes due to the draft nature of our genome assemblies. Further studies will be required to determine the mechanism of carbapenem resistance in this strain.…”

Post-Covid-19 Era: What is Next?

“…As per a study done by Chetri et al, 2019 a strong association between ertapenem resistance and AcrA over-expression was observed which has not been noticed earlier. Also, the over-expression of AcrB towards imipenem stress was noticed in this study is unique of its own [14]. AcrD, a transporter protein which belongs to RND superfamily of efflux pump was found to be associated with aminoglycosides resistance [15] did not show any role in carbapenem resistance in the above study [14].…”