Related Experiment Video
Updated: Apr 27, 2026
Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
Emergence of multidrug-resistant Campylobacter species isolates with a horizontally acquired rRNA methylase
Yang Wang1, Maojun Zhang2, Fengru Deng1
1National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, China.
Abstract:
Antibiotic-resistant Campylobacter constitutes a serious threat to public health, and resistance to macrolides is of particular concern, as this class of antibiotics is the drug of choice for clinical therapy of campylobacteriosis. Very recently, a horizontally transferrable macrolide resistance mediated by the rRNA methylase gene erm(B) was reported in a Campylobacter coli isolate, but little is known about the dissemination of erm(B) among Campylobacter isolates and the association of erm(B)-carrying isolates with clinical disease. To address this question and facilitate the control of antibiotic-resistant Campylobacter, we determined the distribution of erm(B) in 1,554 C. coli and Campylobacter jejuni isolates derived from food-producing animals and clinically confirmed human diarrheal cases. The results revealed that 58 of the examined isolates harbored erm(B) and exhibited high-level resistance to macrolides, and most were recent isolates, derived in 2011-2012. In addition, the erm(B)-positive isolates were all resistant to fluoroquinolones, another clinically important antibiotic used for treating campylobacteriosis. The erm(B) gene is found to be associated with chromosomal multidrug resistance genomic islands (MDRGIs) of Gram-positive origin or with plasmids of various sizes. All MDRGIs were transferrable to macrolide-susceptible C. jejuni by natural transformation under laboratory conditions. Molecular typing of the erm(B)-carrying isolates by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) identified diverse genotypes and outbreak-associated diarrheal isolates. Molecular typing also suggested zoonotic transmission of erm(B)-positive Campylobacter. These findings reveal an emerging and alarming trend of dissemination of erm(B) and MDRGIs in Campylobacter and underscore the need for heightened efforts to control their further spread.
Insights
Antibiotic-resistant Campylobacter is a growing public health threat. The spread of the macrolide resistance gene erm(B) in Campylobacter, linked to genomic islands and plasmids, is alarming and requires urgent control measures.
Area of Science:
- Microbiology
- Genetics
- Public Health
Background:
- Antibiotic-resistant Campylobacter poses a significant public health risk.
- Macrolide resistance in Campylobacter is a major clinical concern, as macrolides are the primary treatment for campylobacteriosis.
- The rRNA methylase gene erm(B) confers macrolide resistance and has been identified in transferable elements within Campylobacter.
Purpose of the Study:
- To investigate the prevalence and dissemination of the erm(B) gene in Campylobacter isolates.
- To determine the association of erm(B)-carrying isolates with clinical disease and food-producing animals.
- To understand the genetic context and transferability of erm(B) in Campylobacter.
Main Methods:
- Screening of 1,554 Campylobacter coli and Campylobacter jejuni isolates from animals and human cases for the erm(B) gene.
- Phenotypic testing for macrolide and fluoroquinolone resistance.
- Analysis of the genetic location of erm(B) (genomic islands or plasmids).
- Assessing the transferability of erm(B)-carrying genomic islands via natural transformation.
- Molecular typing (PFGE and MLST) of erm(B)-positive isolates.
Main Results:
- Fifty-eight Campylobacter isolates harbored the erm(B) gene, exhibiting high-level macrolide resistance.
- All erm(B)-positive isolates were also resistant to fluoroquinolones.
- The erm(B) gene was located on mobile genetic elements, including multidrug resistance genomic islands (MDRGIs) and plasmids.
- MDRGIs carrying erm(B) were successfully transferred to susceptible Campylobacter strains.
- Molecular typing revealed diverse genotypes and identified outbreak-associated isolates, suggesting zoonotic transmission.
Conclusions:
- The erm(B) gene is emerging and spreading rapidly within Campylobacter populations, often linked to MDRGIs.
- Co-resistance to fluoroquinolones is a significant characteristic of erm(B)-positive isolates.
- The transferability of erm(B) via genomic islands and plasmids facilitates its dissemination.
- Findings highlight the urgent need for enhanced surveillance and control strategies to curb the spread of antibiotic-resistant Campylobacter.
Related Concept Videos
01:25Mechanism of Antibiotic Resistance in MRSA
01:25Clinical Significance of Antibiotic Resistance
01:30Development of Antibiotic Resistance
01:19Conjugation