Antimicrobial Susceptibility of Human Pasteurella multocida Isolates in Korea, 2022-2025
Hye Gyung Bae1, Jae Han Sohn2, Hochan Seo2
1Department of Laboratory Medicine, Seoul Clinical Laboratories, Yongin, Korea. hyegyung_bae2@scllab.co.kr.
Background:
Pasteurella multocida is an important zoonotic pathogen that causes soft-tissue infections in humans; however, recent antimicrobial susceptibility data in Korea remain limited.
Materials And Methods:
A total of 70 clinical P. multocida isolates collected at a nationwide commercial laboratory in Korea between November 2022 and July 2025 were analyzed. Antimicrobial susceptibility testing was performed using the disk diffusion method on Mueller-Hinton agar supplemented with 5% sheep blood. Five clinically relevant antimicrobial agents were tested: penicillin, amoxicillin-clavulanic acid (AMC), levofloxacin, tetracycline, and trimethoprim-sulfamethoxazole (TMP-SMX). For isolates classified as penicillin non-susceptible by disk diffusion, minimum inhibitory concentration (MIC) testing was performed using E-test and β-lactamase production was assessed using a phenotypic method.
Results:
All tested isolates were susceptible to tetracycline and TMP-SMX by disk diffusion. Susceptibility rates by disk diffusion were 97.1% for AMC, 91.4% for levofloxacin, and 85.7% for penicillin. All 10 isolates initially classified as penicillin non-susceptible by disk diffusion were confirmed to be susceptible to penicillin by MIC testing and were β-lactamase negative. The 2 isolates classified as non-susceptible to AMC by disk diffusion were also β-lactamase negative and susceptible to penicillin by MIC testing.
Conclusion:
No β-lactam resistance was identified among the 70 clinical P. multocida isolates analyzed. These findings support current recommendations that β-lactams and other first-line agents remain active against P. multocida isolates in Korea.
Insights
This study found no beta-lactam resistance in Pasteurella multocida isolates from Korea. Penicillin and amoxicillin-clavulanic acid remain effective treatments for soft-tissue infections caused by this pathogen.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Pasteurella multocida is a significant zoonotic pathogen causing human soft-tissue infections.
- Limited recent antimicrobial susceptibility data exists for P. multocida in Korea.
Purpose of the Study:
- To assess the antimicrobial susceptibility of clinical P. multocida isolates in Korea.
- To provide updated data on resistance patterns for key antimicrobial agents.
Main Methods:
- Analyzed 70 clinical P. multocida isolates from Korea (Nov 2022-Jul 2025).
- Performed disk diffusion testing for penicillin, amoxicillin-clavulanic acid (AMC), levofloxacin, tetracycline, and trimethoprim-sulfamethoxazole (TMP-SMX).
- Conducted MIC testing and beta-lactamase assays for non-susceptible isolates.
Main Results:
- All isolates were susceptible to tetracycline and TMP-SMX.
- High susceptibility rates observed for AMC (97.1%), levofloxacin (91.4%), and penicillin (85.7%).
- No beta-lactamase production detected; penicillin and AMC non-susceptibility by disk diffusion was not confirmed by MIC.
Conclusions:
- No beta-lactam resistance was identified in the analyzed P. multocida isolates.
- Current recommendations for using beta-lactams and other first-line agents against P. multocida in Korea are supported.
- Findings contribute crucial data for managing P. multocida infections in the region.
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