Multilocus Sequence Types of Campylobacter jejuni Isolates from Different Sources in Eastern China

Area of Science:

• Microbiology
• Genetics
• Food Safety

Background:

• Campylobacter jejuni is a significant food-borne pathogen causing human gastroenteritis globally.
• Understanding its genetic diversity is crucial for effective control strategies.

Purpose of the Study:

• To investigate the genetic diversity of Campylobacter jejuni isolates from various sources in Eastern China.
• To identify novel sequence types and clonal complexes within C. jejuni populations.

Main Methods:

• Applied multilocus sequence typing (MLST) to 167 C. jejuni isolates.
• Analyzed sequence data to define sequence types (STs) and clonal complexes (CCs).
• Compared findings with existing international databases.

Main Results:

• Identified 94 STs and 18 CCs among the isolates.
• Discovered 45 novel STs (36%) and 22 novel alleles not previously documented.
• Found that eight major CCs comprised 61.1% of all isolates and were prevalent across different sources.
• ST-353 was common in human and food isolates, while ST-354 dominated chicken and food isolates.
• Fifteen of 21 multi-source STs included human isolates, suggesting broad host/source adaptability.

Conclusions:

• The study highlights significant genetic diversity in C. jejuni from Eastern China, including novel lineages.
• Identified common clonal complexes and sequence types associated with human illness and food sources.
• Findings suggest that pathogenic C. jejuni strains are not confined to specific genetic lineages, posing a broad public health risk.