Kaczorek Edyta, Małaczewska Joanna, Wójcik Roman, Siwicki Andrzej Krzysztof
Department of Microbiology and Clinical Immunology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland.
BMC Vet Res. 2017 Dec 28;13(1):398. doi: 10.1186/s12917-017-1322-y.
Mastitis is a common disease in dairy cattle throughout the world and causes considerable economic losses each year. An important aetiological agent of this disease is bacteria of the genus Streptococcus; hence, exploring the mechanisms of virulence in these bacteria is an extremely important step for the development of effective prevention programmes. The purpose of our study was to determine the ability to produce biofilm and the occurrence of selected invasiveness factors among bacteria of the genus Streptococcus isolated from cattle with the clinical form of mastitis in northeastern Poland.
Most of the isolates analysed demonstrated an ability to produce biofilm (over 70%). Virulence genes were searched for in the three most common streptococci in our experiment: S. agalactiae, S. uberis and S. dysgalactiae. For S. agalactiae, only four genes were confirmed: rib (33%), cylE (78%), bca (37%), and cfb (100%). The genes pavA, scpB, bac and lmb were not present in any of the tested strains. The dominant serotypes of the species were Ia (n = 8) and II (n = 8), in addition to some strains that were not classified in any of the groups (n = 6). Out of the eight selected genes for S. uberis (sua, pauA/skc, gapC, cfu, lbp, hasA, hasB, hasC), only one was not found (lbp). Finally, two genes were chosen for S. dysgalactiae (eno and napr), and their presence was confirmed in 76% and 86% of the strains, respectively.
The experiment showed that strains of Streptococcus spp. isolated from dairy cattle with clinical cases of mastitis in the northeastern part of Poland possess several invasiveness factors that can substantially affect the course of the disease, and this should be considered when developing targeted prevention programmes.
乳腺炎是全球奶牛的常见疾病，每年造成相当大的经济损失。该疾病的一个重要病原体是链球菌属细菌；因此，探索这些细菌的毒力机制是制定有效预防方案的极其重要的一步。我们研究的目的是确定从波兰东北部患有临床型乳腺炎的奶牛中分离出的链球菌属细菌产生生物膜的能力以及所选侵袭性因子的出现情况。
分析的大多数分离株显示出产生生物膜的能力（超过70%）。在我们实验中三种最常见的链球菌中搜索毒力基因：无乳链球菌、乳房链球菌和停乳链球菌。对于无乳链球菌，仅确认了四个基因：rib（33%）、cylE（78%）、bca（37%）和cfb（100%）。pavA、scpB、bac和lmb基因在任何测试菌株中均未出现。该物种的主要血清型为Ia（n = 8）和II（n = 8），此外还有一些未归入任何组别的菌株（n = 6）。在为乳房链球菌选择的八个基因（sua、pauA/skc、gapC、cfu、lbp、hasA、hasB、hasC）中，仅未发现一个基因（lbp）。最后，为停乳链球菌选择了两个基因（eno和napr），分别在76%和86%的菌株中确认了它们的存在。
实验表明，从波兰东北部患有乳腺炎临床病例的奶牛中分离出的链球菌属菌株具有几种侵袭性因子，这些因子可显著影响疾病进程，在制定针对性预防方案时应予以考虑。
