Institute of Microbiology and Epizootics, Freie Universität Berlin, Germany; Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut (FLI), Neustadt-Mariensee, Germany.
Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Germany.
Vet Microbiol. 2018 Jun;219:165-170. doi: 10.1016/j.vetmic.2018.03.030. Epub 2018 Apr 4.
The collaboration project VASIB aims at reducing the antibiotic consumption in pig production by integrating information from consulting expertise in clinical inspection, hygiene, epidemiology, microbiology and pharmacology. In this VASIB subproject, we investigated the antimicrobial susceptibility and relatedness of porcine respiratory tract pathogens. Bordetella bronchiseptica (n = 47), Pasteurella multocida (n = 18) and Streptococcus suis (n = 58) were obtained from weaner pigs at two farms. Antimicrobial susceptibility testing was performed by broth microdilution according to CLSI standards. Resistance genes were detected via specific PCR assays. Macrorestriction analysis was conducted to determine the relatedness of the isolates and to identify clones. The B. bronchiseptica isolates showed indistinguishable (farm 1) or two closely related XbaI-patterns (farm 2). Different SmaI-PFGE patterns of P. multocida isolates were obtained at three different time points. In contrast, PFGE analysis of S. suis indicated more than one fragment pattern per pig and time point. Isolates exhibiting indistinguishable PFGE patterns were considered to represent the same clone. This study showed that only two closely related B. bronchiseptica clones were present in both farms, which had low MICs to all antimicrobials, except to β-lactams. Different P. multocida clones were present at the three time points. They showed overall low MIC values, with two clones being resistant and one intermediate to tetracycline. S. suis clones were resistant to tetracycline (n = 19) and/or erythromycin/clindamycin (n = 16). They harboured the tetracycline resistance genes tet(O), tet(M) or tet(L) and/or the macrolide/lincosamide/streptogramin B resistance gene erm(B). Five penicillin-resistant S. suis clones were also detected.
合作项目 VASIB 旨在通过整合临床检查、卫生、流行病学、微生物学和药理学方面的咨询专业知识，减少猪生产中的抗生素使用。在这个 VASIB 子项目中，我们研究了猪呼吸道病原体的抗菌敏感性和相关性。从两个农场的断奶猪中获得了支气管败血波氏杆菌（n=47）、多杀性巴氏杆菌（n=18）和猪链球菌（n=58）。根据 CLSI 标准，通过肉汤微量稀释法进行抗菌敏感性测试。通过特异性 PCR 检测来检测耐药基因。通过宏限制分析来确定分离株的相关性并鉴定克隆。支气管败血波氏杆菌分离株在农场 1 表现出无法区分的（农场 1）或两种密切相关的 XbaI 模式（农场 2）。在三个不同的时间点获得了多杀性巴氏杆菌分离株的不同 SmaI-PFGE 模式。相比之下，猪链球菌的 PFGE 分析表明，每个猪和时间点都有不止一种片段模式。表现出无法区分的 PFGE 模式的分离株被认为代表相同的克隆。本研究表明，只有两个密切相关的支气管败血波氏杆菌克隆存在于两个农场中，它们对所有抗生素的 MIC 均较低，除了β-内酰胺类抗生素。在三个时间点都存在不同的多杀性巴氏杆菌克隆。它们总体上 MIC 值较低，有两个克隆对四环素耐药，一个中间耐药。猪链球菌克隆对四环素（n=19）和/或红霉素/克林霉素耐药（n=16）。它们携带四环素耐药基因 tet(O)、tet(M)或 tet(L)和/或大环内酯/林可酰胺/链阳性菌素 B 耐药基因 erm(B)。还检测到五个青霉素耐药的猪链球菌克隆。
