The present study describes an outbreak of Pseudomonas (P.) aeruginosa mastitis in a 20-cow dairy herd where throughout genotyping of isolates reusable udder towels were identified as the source of infection. Sampling of cows during three herd surveys and bacteriological culturing showed that P. aeruginosa was isolated from nine cows with a total of 13 infected quarters. Mastitis occurred as mild clinical or subclinical infection. P. aeruginosa was additionally isolated from a teat disinfectant solution, containing N-(3-aminopropyl)-N-dodécylpropane-1,3-diamine 1 as active component, and microfiber towels used for pre-milking teat preparation. Disc diffusion antimicrobial resistance testing revealed that all isolates were susceptible to piperacillin, piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, tobramycin, amikacin, and ciprofloxacin. Thirty-two isolates of milk samples and 22 randomly selected isolates of one udder towel and of the teat disinfectant solution were confirmed as P. aeruginosa with matrix-assisted laser desorption, ionization time-of-flight mass spectrometry (MALDI Tof MS). Isolates were further characterized with rep-PCR and randomly amplified polymorphic DNA (RAPD) as well as with multiple locus variable-number tandem repeat analysis (MLVA). Results obtained in this study suggested that one single strain was responsible for the whole outbreak. The transmission occurred throughout a contaminated teat cleaning solution as a source of infection. The farmer was advised to change udder-preparing routine and to cull infected cows.

中文翻译：

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追踪乳腺炎的病原体—奥地利奶牛群中铜绿假单胞菌乳腺炎暴发的流行病学调查

本研究描述了在20头牛群中的铜绿假单胞菌（P.）铜绿假单胞菌乳腺炎的暴发，在该菌的基因型分型中，可重复使用的乳房毛巾被确定为感染源。在三个牛群调查和细菌培养中对牛进行了抽样调查，结果表明，铜绿假单胞菌是从9头母牛中分离出来的，总共感染了13个季度。乳腺炎发生为轻度临床或亚临床感染。铜绿假单胞菌另外，从包含N-（3-氨基丙基）-N-十二烷基丙烷-1,3-二胺1作为活性成分的乳头消毒液中分离出尿素，并用超细纤维毛巾预挤乳头。椎间盘扩散抗药性测试表明，所有分离株均对哌拉西林，哌拉西林-他唑巴坦，头孢他啶，头孢吡肟，氨曲南，亚胺培南，美罗培南，妥布霉素，阿米卡星和环丙沙星敏感。确认了32份牛奶样品分离株和22份随机选择的1条乳房毛巾和乳头消毒液分离株被鉴定为铜绿假单胞菌。基质辅助激光解吸，电离飞行时间质谱（MALDI Tof MS）。分离株用rep-PCR和随机扩增的多态性DNA（RAPD）以及多基因座可变数串联重复分析（MLVA）进一步表征。这项研究获得的结果表明，一个单独的毒株是整个暴发的原因。传播发生在整个被污染的奶头清洁液中，作为感染源。建议该农场主改变准备乳房的常规，并剔除被感染的母牛。