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A molecular survey of Campylobacter jejuni and Campylobacter coli virulence and diversity
Mahdi Ghorbanalizadgan1, Bita Bakhshi1, Anoshirvan Kazemnejad Lili2
1Dept. of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Insights
This study investigated virulence genes in Campylobacter spp. from Iranian children with diarrhea. Most isolates carried flaA, cadF, and ciaB genes, with distinct genetic profiles correlating with location and virulence factors.
Area of Science:
- Microbiology
- Molecular Epidemiology
- Infectious Diseases
Background:
- Campylobacter species are a leading cause of bacterial gastroenteritis worldwide.
- Understanding the prevalence of virulence factors is crucial for diagnosing and managing Campylobacter infections in children.
- Limited molecular data exists on Campylobacter isolates from pediatric diarrhea cases in Iran.
Purpose of the Study:
- To determine the prevalence of key virulence-associated genes in Campylobacter spp.
- To analyze the genetic diversity of Campylobacter isolates using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR).
- To investigate the correlation between genetic profiles, virulence gene content, and geographic origin in Iranian children.
Main Methods:
- Stool specimens from 200 children under 5 years were analyzed.
- Campylobacter jejuni and Campylobacter coli were identified using standard biochemical and molecular techniques.
- Polymerase chain reaction (PCR) was employed to detect virulence genes (flaA, cadF, ciaB, virB11, pldA, CDT) and ERIC-PCR was used for genotyping.
Main Results:
- Twelve Campylobacter isolates (6%) were identified: 10 C. jejuni and 2 C. coli.
- The flaA, cadF, and ciaB genes were universally present (100%).
- Invasion-associated markers were found in all C. coli but not C. jejuni. pldA and CDT genes were present in 58.3% of C. jejuni. Seven distinct ERIC-PCR profiles were observed, showing correlation with geographic location and virulence gene profiles.
Conclusions:
- This is the first molecular study in Iran to assess Campylobacter genotyping and virulence gene content in pediatric diarrhea.
- ERIC-PCR demonstrated effective discriminatory power for clustering C. jejuni isolates with similar virulence gene profiles.
- Further research is necessary to elucidate the pathogenic roles of specific Campylobacter genotypes.
Background:
The aim of this study was to determine the prevalence of virulence-associated genes and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) analysis of Campylobacter spp. isolated from children with diarrhea in Iran.
Methods:
A total of 200 stool specimens were obtained from children under 5 years during July 2012 to July 2013. Detection of C. jejuni and C. coli was performed by standard biochemical and molecular methods. The presence of virulence-associated genes and genetic diversity of isolates was examined using PCR and ERIC-PCR analyses.
Results:
A total of 12 (6%) Campylobacter spp. were isolated from patients including 10 (4.5%) C. jejuni and 2 (1.5%) C.coli. The flaA, cadF and ciaB genes were present in 100% of isolates, while no plasmid of virB11 gene was present in their genome. The prevalence of invasion-associated marker was 100% among C. coli and was not detected in C. jejuni isolates. The distribution of both pldA and the genes associated with cytolethal distending toxin (CDT) was 58.3% in C. jejuni isolates. Seven distinct ERIC-PCR profiles were distinguished in three clusters using ERIC-PCR analysis. Genotyping analysis showed a relative correlation with geographic location of patients and virulence gene content of isolates.
Conclusion:
To our knowledge, this is the first molecular survey of Campylobacter spp. in Iran concerning genotyping and virulence gene content of both C. jejuni and C. coli. ERIC-PCR revealed appropriate discriminatory power for clustering C. jejuni isolates with identical virulence gene content. However, more studies are needed to clearly understand the pathogenesis properties of specific genotypes.