Serovars and antimicrobial resistance profiles of Actinobacillus pleuropneumoniae isolates from clinical-case pigs in Taiwan
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Pleuropneumonia remains an important challenge to swine production worldwide. The causative agent, Actinobacillus pleuropneumoniae serovar prevalence in countries can change over time. Few Taiwanese A. pleuropneumoniae prevalence studies have been published, and recent large-scale investigations remain notably scarce. This study aimed to identify the serovars and antimicrobial sensitivity of 96 current Taiwanese A. pleuropneumoniae clinical isolates.
Results
Among the 99 A. pleuropneumoniae determinations, 40 (40.4%) were serovar 15, 29 (29.3%) were serovar 5, 15 (15.2%) were serovar 1, 11 (11.1%) were serovar 7, and 4 (4.0%) were serovar 2. Therefore serovar 15 was the most predominant between 2015 and 2022. Resistance of the isolates was minimal to ceftiofur (3.2%), cephalexin (5.2%), cephalothin (6.3%) and enrofloxacin (9.3%), moderate to gentamicin (28.4%), and high for florfenicol, amoxicillin and ampicillin (45.1–68.4%).
Conclusions
This study updates the serovar and antimicrobial sensitivity patterns of Taiwanese clinical A. pleuropneumoniae isolates, showing that serovars 15, 5, 1, 7, and 2 collectively predominate in clinical outbreaks. Local A. pleuropneumoniae isolates exhibited high resistance to antimicrobials currently used in the Taiwanese pig production, such as amoxicillin, ampicillin, and florfenicol. However, there was low resistance to cephalexin, cephalothin, tilmicosin and lincospectin (injectable only) which can be recommended for current use in Taiwan, considering both efficacy and public health risks. Notably, isolates of the same serovar collected from the same farm on the same day occasionally displayed distinct resistance patterns, emphasizing the complex dynamics of antimicrobial resistance. Our data will help veterinarians and producers refine vaccination and treatment protocols, highlighting the importance of ongoing surveillance to respond effectively to evolving resistance trends.
Pleuropneumonia remains an important challenge to swine production worldwide. The causative agent, Actinobacillus pleuropneumoniae serovar prevalence in countries can change over time. Few Taiwanese A. pleuropneumoniae prevalence studies have been published, and recent large-scale investigations remain notably scarce. This study aimed to identify the serovars and antimicrobial sensitivity of 96 current Taiwanese A. pleuropneumoniae clinical isolates.
Results
Among the 99 A. pleuropneumoniae determinations, 40 (40.4%) were serovar 15, 29 (29.3%) were serovar 5, 15 (15.2%) were serovar 1, 11 (11.1%) were serovar 7, and 4 (4.0%) were serovar 2. Therefore serovar 15 was the most predominant between 2015 and 2022. Resistance of the isolates was minimal to ceftiofur (3.2%), cephalexin (5.2%), cephalothin (6.3%) and enrofloxacin (9.3%), moderate to gentamicin (28.4%), and high for florfenicol, amoxicillin and ampicillin (45.1–68.4%).
Conclusions
This study updates the serovar and antimicrobial sensitivity patterns of Taiwanese clinical A. pleuropneumoniae isolates, showing that serovars 15, 5, 1, 7, and 2 collectively predominate in clinical outbreaks. Local A. pleuropneumoniae isolates exhibited high resistance to antimicrobials currently used in the Taiwanese pig production, such as amoxicillin, ampicillin, and florfenicol. However, there was low resistance to cephalexin, cephalothin, tilmicosin and lincospectin (injectable only) which can be recommended for current use in Taiwan, considering both efficacy and public health risks. Notably, isolates of the same serovar collected from the same farm on the same day occasionally displayed distinct resistance patterns, emphasizing the complex dynamics of antimicrobial resistance. Our data will help veterinarians and producers refine vaccination and treatment protocols, highlighting the importance of ongoing surveillance to respond effectively to evolving resistance trends.
Date Issued
2025-08-04
Date Acceptance
2025-06-13
Citation
BMC Veterinary Research, 2025, 21
ISSN
1746-6148
Publisher
BMC
Journal / Book Title
BMC Veterinary Research
Volume
21
Copyright Statement
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Publication Status
Published
Article Number
502
Date Publish Online
2025-08-04