전남지역 발생 사례별 단상편모 살모넬라균의 특성 분석

고은별, 강보라, 임형우, 나혜영, 양혜린, 박숙

미생물과

Molecular Characteristics of Salmonella I 4,[5],12:i:- Isolates from Jeollanam-do, South Korea

E. B. Go, B. R. Kang, H. W. Lim, H. Y. Na, H. R. Yang. S. Park

Microbiology Division

Abstract

Salmonella is a major foodborne pathogen and one of the leading causes of food poisoning and antimicrobial resistance(AMR) dissemination, making its study critical for public health and food safety. This study aimed to compare the distribution of virulence genes, antimicrobial resistance genes(ARGs), and plasmid types among Salmonella enterica serovar I 4,[5],12:i:- isolates obtained from various sources in Jeollanam-do Province, South Korea. A total of 44 S. I 4,[5],12:i:- isolates collected between 2021 and 2023 were analyzed using pulsed-field gel electrophoresis(PFGE) and whole-genome sequencing(WGS). In silico analyses were performed using the Center for Genomic Epidemiology(CGE) web tools, and the results were visualized using R software. The distribution of Salmonella pathogenicity islands(SPIs), ARGs, and plasmid types was compared according to MLST type.

PFGE results showed that the isolates were grouped into two major clusters, which corresponded to distinct sequence types(ST). Analysis of Salmonella pathogenicity island revealed that C63PI was frequently detected in ST34 isolates, which also harbored various ARGs. In contrast, plasmid analysis revealed that ST19 isolates carried a broader range of Inc-type plasmids, including IncFIB, IncFII, and IncI1-I(α).

Although no clear genetic clustering was observed based on isolation source, the genetic characteristics of the isolates were strongly associated with MLST types. Further experimental studies are needed to clarify the relationship between these genetic traits and phenotypic resistance or transmissibility.

Key words : Salmonella I 4,[5],12:i:-, Molecular epidemiology, PFGE, WGS

1. 본 연구에서는 전라남도에서 분리된 Salmonella enterica serovar I 4,[5],12:i:- 균주 44주를 대상으로 PFGE와 전장유전체분석(WGS)을 통해 병원성 유전자, 항생제 내성 유전자, 플라스미드 보유 양상을 분석하였다.

2. 분석 결과, 균주의 유전적 특성은 분리원보다는 MLST 유형에 따라 구분되었으며, ST34는 다양한 항생제 내성 유전자를, ST19는 다양한 Inc-type 플라스미드를 보유한 것으로 확인되었다.

3. 이 결과는 Salmonella I 4,[5],12:i:- 균주의 특성이 분리원보다 유전적 계통에 의해 결정된다는 점을 시사하며, 실제 내성 표현형과의 상관성을 확인하기 위한 후속 연구가 필요하다.

4. 본 연구는 살모넬라균의 전파 특성 이해와 공중보건 및 식품안전 관점에서의 감시체계 수립에 기여할 수 있는 기초자료를 제공한다.