The objective of our study was to evaluate prevalence of selected bacterial and fungal pathogens of mastitis in dairy cattle in north-eastern Poland. Our study was conducted from 2013 to 2019 in 1,665 clinically and sub-clinically infected quarter milk samples (2013, n = 368; 2014, n = 350; 2015, n = 290; 2016, n = 170; 2017, n = 173; 2018, n = 224; and 2019, n = 90). The isolation and identification of the pathogens were performed in keeping with generally accepted microbiological procedures. In 2013, mastitis was most commonly caused by Staphylococcus aureus (24%), Streptococcus spp. (22%), Streptococcus agalactiae (12%) and coagulase-negative staphylococci (11%). In 2014, the most common pathogens were Streptococcus spp. (25%), Staphylococcus aureus (18%) and coagulase-negative staphylococci (10%); in 2015, 2016, 2017, 2018 and 2019, Streptococcus spp. (from 39–49%) were the most frequent strains isolated from the quarter milk samples. Other pathogens were isolated occasionally (below 15% in all years). In conclusion, the role of environmental bacteria has been gradually increasing in the Warmia Province. The importance of infectious pathogens has been decreasing, indicating the efficacy of the applied preventive programmes and a need for the development of new programmes targeting environmental pathogens.

中文翻译：

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链球菌作为波兰东北部奶牛乳腺炎的新主要病因：2013-2019 年结果分析

我们研究的目的是评估波兰东北部奶牛乳腺炎的特定细菌和真菌病原体的流行情况。我们的研究从 2013 年到 2019 年在 1,665 个临床和亚临床感染的四分之一牛奶样本中进行（2013 年，n = 368；2014 年，n = 350；2015 年，n = 290；2016 年，n = 170；2017 年，n = 173； 2018 年，n = 224；和 2019 年，n = 90）。按照普遍接受的微生物程序进行病原体的分离和鉴定。2013 年，乳腺炎最常见的原因是金黄色葡萄球菌 (24%)、链球菌属。(22%)、无乳链球菌 (12%) 和凝固酶阴性葡萄球菌 (11%)。2014 年，最常见的病原体是链球菌属。(25%)、金黄色葡萄球菌 (18%) 和凝固酶阴性葡萄球菌 (10%)；在 2015 年、2016 年、2017 年、2018 年和 2019 年，链球菌属 （从 39% 到 49%）是从四分之一牛奶样品中分离出的最常见菌株。偶尔会分离出其他病原体（所有年份均低于 15%）。总之，环境细菌的作用在瓦尔米亚省逐渐增加。传染性病原体的重要性一直在下降，这表明所应用的预防计划的有效性以及需要开发针对环境病原体的新计划。