Objectives: This study was conducted to examine the genetic variation occurring in the cmeB gene encoding the transporter component of the CmeABC efflux pump.
Methods: Expression of the CmeABC pump in 21 strains of Campylobacter jejuni and Campylobacter coli was studied by western-blot analysis. MIC determination was conducted in the presence or absence of an efflux pump inhibitor (EPI). Inactivation of the cmeB gene and sequencing of the cmeABC operon were performed for a single strain. The remaining strains were compared by RFLP analysis of the cmeB-specific PCR amplicon. The cmeB genes of two C. coli strains with different RFLP patterns were sequenced completely.
Results: Conflicting results were obtained in the western-blot analysis with anti-CmeB and anti-CmeC antibodies for one strain, whereas MIC determinations with EPI and cmeB gene inactivation confirmed the efflux pump's activity. The cmeB gene of this isolate showed only 78% nucleotide sequence identity with the sequence of reference strains. PCR-RFLP analysis identified 4 different patterns among the 5 C. jejuni and 14 different patterns among the 16 C. coli strains investigated. At the amino acid sequence level, variation was higher in the periplasmic loops of the transporter.
Conclusions: A total of 18 different cmeB-specific PCR-RFLP patterns were detected among the 21 C. jejuni and C. coli strains. These sequence variations might have an impact on the function and substrate recognition of this transporter. The sequence data obtained in this study will help to design suitable tools to study the presence or the expression of the gene cmeB.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1093/jac/dkl212 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sharing of alleles between and associated with extensive drug resistance in isolates from infants and poultry in the Peruvian Amazon.
mBio
December 2024
Division of Infectious Diseases and International Health, School of Medicine, University of Virginia, Charlottsville, Virginia, USA.
is a serious health threat because of the rapid progressive evolution of antimicrobial resistance and efficient transmission from zoonotic as well as human sources. Resistance to fluoroquinolones and macrolides is particularly concerning as this compromises the two most effective oral antibiotic agents currently available for human campylobacteriosis. Here, we report on the prevalence and worldwide distribution of the operon , which encodes an efflux pump conferring high levels of combined resistance to fluoroquinolones and macrolides in strains isolated from poultry ( = 75) and children ( = 177).
View Article and Find Full Text PDFMutation-based mechanism and evolution of the potent multidrug efflux pump RE-CmeABC in .
Proc Natl Acad Sci U S A
December 2024
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011.
Article Synopsis
- The RND superfamily of multidrug efflux systems is crucial for antibiotic resistance in gram-negative pathogens, specifically highlighting how the CmeABC system in a major enteric pathogen extrudes antibiotics.
- A new variant, RE-CmeABC, has emerged in clinical isolates, showing enhanced resistance due to specific amino acid changes in RE-CmeB and a promoter mutation, though the exact molecular mechanisms for its improvements are still unclear.
- RE-CmeABC is spreading globally among diverse strains, particularly associated with human infections, suggesting the variant's clinical significance, while evolutionary evidence hints at its origin and expansion driven by antibiotic selection pressure.
Gene profile of virulence, antimicrobial resistance and action of enterocins in Campylobacter species isolated from broiler carcasses.
Braz J Microbiol
November 2024
Department of Veterinary Medicine, Federal Rural University of Pernambuco, Av. Dom Manoel de Medeiros, s/n, Dois Irmãos, Recife, Pernambuco, CP 52171-900, Brazil.
Article Synopsis
- * This study aimed to assess the levels of Campylobacter contamination in chilled and frozen chicken carcasses sold in Northeast Brazil, identifying virulence genes and antibiotic resistance, as well as testing the antimicrobial effectiveness of a probiotic extract from Enterococcus faecium.
- * Out of 376 isolates, 26 (7.0%) were identified as C. jejuni, predominantly from chilled carcasses (88.5%), while no C.
Isolation, characterization, and antimicrobial resistance profiles of and from raw meat of large livestock in Shahrekord, Iran.
Arch Razi Inst
February 2024
Research Center of Nutrition and Organic Products, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
spp. genera is one of the most common causes of microbial enteritis worldwide. This study aimed to find out how common Campylobacter organisms were in raw meat from large livestock in Iran, as well as to determine their antibiotic susceptibility profiles.
View Article and Find Full Text PDFMetagenomic analysis reveals the mechanisms of biochar supported nano zero-valent iron in two-phase anaerobic digestion of food waste: microbial community, CAZmey, functional genes and antibiotic resistance genes.
J Environ Manage
August 2024
Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China; Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing, 100048, China.
The mechanisms of biochar supported nano zero-valent iron (BC/nZVI) on two-phase anaerobic digestion of food waste were investigated. Results indicated that the performance of both acidogenic phase and methanogenic phase was effectively facilitated. BC/nZVI with the amount of 120 mg/L increased methane production by 32.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!