S-Space College of Veterinary Medicine (수의과대학) Dept. of Veterinary Medicine (수의학과) Theses (Master's Degree_수의학과)
The difference on the third generation cephalosporin resistance in Escherichia coli from raw milk
Ceftiofur의 사용에 따른 국내 원유 분리 Escherichia coli의 3세대 세팔로스포린계 항생제에 대한 내성 차이
- 수의과대학 수의학과
- Issue Date
- 서울대학교 대학원
- 학위논문 (석사)-- 서울대학교 대학원 : 수의과대학 수의학과, 2018. 8. 박용호.
- The antimicrobial resistance to the third-generation cephalosporins (3G-Ceph) in gram negative bacteria is an emerging concern worldwide. The prevalence of 3G-Ceph resistant bacteria in livestock has also increased in the past a few years in Korea. It is important to elucidate the relatedness between the use of 3G-Ceph and the increased antimicrobial resistance to these antimicrobials in local farms. The current study was performed to evaluate the effect of 3G-Ceph (ceftiofur) use on the increase of antimicrobial resistance by comparing the antimicrobial resistant rates between 3G-Ceph (ceftiofur) using and non-using farms. A total of 160 Escherichia coli (123 from using and 37 from non-using farms) were isolated from raw milk. The antimicrobial resistant rate to 3G-Ceph was significantly higher in 3G-Ceph using farms (9.8%) than in non-using farms (2.7%). The MICs of Ceftriaxone, Cefotaxime were measured as less than 4 ug/ml in isolates from non-using farms while 64-1024 ug/ml from using farms. All the resistant isolates from using farms harbored a CTX-M gene, whereas none from non-using farms. Contaminated raw milk can be a vehicle for transmission of antimicrobial resistant bacteria from dairy to humans. The current study indicates the overuse of 3G-Ceph in dairy farms could increase the risk of transmission of 3G-Ceph resistant bacteria to a human community. Therefore, prudent use of this category of antimicrobials in dairy farms is warranted to prevent the dissemination of 3G-Ceph bacteria from animals to humans.