scholarly journals Transcriptional response of Mar, Sox and Rob regulon against concentration gradient carbapenem stress within Escherichia coli isolated from hospital acquired infection

2020 ◽  
Author(s):  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Deepshikha Bhowmik ◽  
Debadatta Dhar Chanda ◽  
Atanu Chakravarty ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Concentration Gradient ◽  
Efflux Pump ◽  
Transcriptional Response ◽  
Multiple Antibiotic Resistance ◽  
Pump System ◽  
Hospital Acquired Infection ◽  
Outer Membrane Porin ◽  
Hospital Acquired

Abstract Objective The present study was carried out to investigate the transcriptional response of marA (Multiple antibiotic resistance A gene), soxS (Superoxide S gene) and rob (Right-origin-binding gene) under carbapenem stress. Results 12 isolates over-expressing AcrAB-TolC efflux pump system and showing reduced expression of OmpF (Outer membrane porin) gene were selected for further study. Among them, overexpression of marA and rob was observed in 7 isolates. Increasing pattern of expression of marA and rob against meropenem was observed. The clones of marA and rob showed reduced susceptibility towards carbapenems.

scholarly journals Transcriptional response of Mar, Sox and Rob regulon against concentration gradient carbapenem stress within Escherichia coli isolated from hospital acquired infection

2020 ◽  
Author(s):  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Deepshikha Bhowmik ◽  
Debadatta Dhar Chanda ◽  
Atanu Chakravarty ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Concentration Gradient ◽  
Efflux Pump ◽  
Transcriptional Response ◽  
Multiple Antibiotic Resistance ◽  
Pump System ◽  
Hospital Acquired Infection ◽  
Outer Membrane Porin ◽  
Hospital Acquired

Abstract Objective The present study was carried out to investigate the transcriptional response of marA (Multiple antibiotic resistance A gene), soxS (Superoxide S gene) and rob (Right-origin-binding gene) under carbapenem stress. Results 12 isolates over-expressing AcrAB-TolC efflux pump system and showing reduced expression of OmpF (Outer membrane porin) gene were selected for further study. Among them, overexpression of marA and rob was observed in 7 isolates. Increasing pattern of expression of marA and rob against meropenem was observed. The clones of marA and rob showed reduced susceptibility towards carbapenems.

The Escherichia coli multiple antibiotic resistance activator protein represses transcription of the lac operon

2019 ◽  
Vol 47 (2) ◽  
pp. 671-677
Author(s):  
Anna Lankester ◽  
Shafayeth Ahmed ◽  
Lisa E. Lamberte ◽  
Rachel A. Kettles ◽  
David C. Grainger
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Regulatory Region ◽  
Lac Operon ◽  
Multiple Antibiotic Resistance ◽  
E Coli ◽  
Genes Encoding ◽  
Response Systems ◽  
A Site

AbstractIn Escherichia coli, the marRAB operon is a determinant for antibiotic resistance. Such phenotypes require the encoded transcription factor MarA that activates efflux pump expression. To better understand all genes controlled by MarA, we recently mapped binding of the regulator across the E. coli genome. As expected, many MarA targets were adjacent to genes encoding stress response systems. Surprisingly, one MarA-binding site overlapped the lac operon regulatory region. Here, we show that MarA specifically targets this locus and can block transcription of the lac genes. Repression is mediated by binding of MarA to a site overlapping the lacP1 promoter −35 element. Control of the lac operon by MarA does not impact antibiotic resistance.

scholarly journals Association of Efflux Pump and OMPs with Antibiotic Susceptibility Among ESBL-Producing Klebsiella Pneumoniae Clinical Strains in Malaysia

2021 ◽  
Author(s):  
Golnaz Mobasseri ◽  
Thong Kwai Lin ◽  
Cindy Shuan Ju Teh
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Antibiotic Susceptibility ◽  
Efflux Pump ◽  
Outer Membrane Proteins ◽  
Multidrug Resistant ◽  
Efflux Pump Inhibitor ◽  
Pump System ◽  
Extended Spectrum Beta Lactamases ◽  
Amoxicillin Clavulanate

Abstract Multidrug-resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) poses a serious public health threat. K. pneumoniae strains that produce extended-spectrum beta-lactamases (ESBL) are becoming increasingly reported in nosocomial and community-acquired infections. Besides resistance genes, integrons, and plasmids, altered membrane permeability caused by porin loss and energy-dependent efflux have also contributed to antibiotic resistance in K. pneumoniae. The objective of this study was to determine the correlation between the reduction of antibiotic susceptibility and overexpression of efflux pump as well as the lack of outer membrane proteins (OMPs) among clinical ESBLs resistant K. pneumoniae. The expression levels of ramA, acrA, ompK35 and ompK36 in 12 MDR K. pneumoniae strains with varying MICs levels were analyzed using quantitative real time-Polymerase Chain Reaction (qRT-PCR). The role of efflux pump on antibiotic resistance was also studied by using minimum inhibitory concentration (MICs) method with//without efflux pump inhibitor. The result indicated that the strains with highest resistance to cefotaxime showed the lowest level of ompK35 and ompK36 genes expression while the strains with lowest MIC level of resistance to cefotaxime showed the highest level of expression of acrA and ramA. Our finding also revealed the effect of efflux pump inhibitor phenyl-arginine-b-naphthylamide (PAβN) on the MIC levels of ceftazidime, amoxicillin-clavulanate and cefotaxime which were significantly reduced around 1–7 folds MIC levels. These results suggest that Efflux pump system and deficiently of OMPs contributing role in antibiotic susceptibility which should be taken seriously to prevent the treatment failure due to antimicrobial resistance.

scholarly journals Inhibition of the multiple antibiotic resistance (mar) operon in Escherichia coli by antisense DNA analogs.

1997 ◽  
Vol 41 (12) ◽  
pp. 2699-2704 ◽  
Author(s):  
D G White ◽  
K Maneewannakul ◽  
E von Hofe ◽  
M Zillman ◽  
W Eisenberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Antisense Oligonucleotides ◽  
Multiple Antibiotic Resistance ◽  
Wild Type ◽  
Lacz Expression ◽  
E Coli ◽  
Plasmid Construct ◽  
Dna Analogs ◽  
Susceptibility And Resistance

The multiple antibiotic resistance operon (marORAB) in Escherichia coli controls intrinsic susceptibility and resistance to multiple, structurally different antibiotics and other noxious agents. A plasmid construct with marA cloned in the antisense direction reduced LacZ expression from a constitutively expressed marA::lacZ translational fusion and inhibited the induced expression of LacZ in cells bearing the wild-type repressed fusion. The marA antisense construction also decreased the multiple antibiotic resistance of a Mar mutant. Two antisense phosphorothioate oligonucleotides, one targeted to marO and the other targeted to marA of the mar operon, introduced by heat shock or electroporation reduced LacZ expression in the strain having the marA::lacZ fusion. One antisense oligonucleotide, tested against a Mar mutant of E. coli ML308-225, increased the bactericidal activity of norfloxacin. These studies demonstrate the efficacy of exogenously delivered antisense oligonucleotides targeted to the marRAB operon in inhibiting expression of this chromosomal regulatory locus.

The association of acetylacetate (Acr AB-Tol C) and QepA genes with multiple antibiotic resistance among Escherichia coli clinical isolates

2019 ◽  
Vol 31 (3) ◽  
pp. 159-164
Author(s):  
Yaqdhan Alnomani ◽  
Abdolmajid Ghasemian ◽  
Mojtaba Memariani ◽  
Majid Eslami ◽  
Abdolreza Sabokrouh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Clinical Isolates ◽  
Multiple Antibiotic Resistance
Sign in / Sign up

Export Citation Format

Share Document