Valkovska Linda, Mališevs Artjoms, Kovaļenko Kaspars, Bērziņš Aivars, Grantiņa-Ieviņa Lelde
Faculty of Veterinary Medicine, Latvia University of Life Sciences and Technologies, Jelgava, LV-3004, Latvia.
Institute of Food Safety, Animal Health and Environment "BIOR", Riga, Jelgava LV-1076, Latvia.
J Vet Res. 2021 Oct 20;65(4):441-447. doi: 10.2478/jvetres-2021-0055. eCollection 2021 Dec.
Q fever in dairy cattle has been investigated in Latvia since 2012. In 2015, 10.7% of farms tested positive for the DNA of , its aetiological agent, in bulk tank milk. The presence of DNA and infectious bacteria in dairy products has been assessed in several countries, and because Latvian milk may contain them, parallel assessment in this country is recommended. Accordingly, the present study tested shop and farm retail dairy products from Latvia and included foreign products for comparison.
Investigation was carried out of 187 samples of a diverse range of dairy products from 41 Latvian milk producers. Twenty-six comparable samples pooled from Estonia, France, Germany, Greece, Italy, Lithuania, the Netherlands, Poland and Spain were also included. The all-countries total number of fermented milk products was 160. Special attention was paid to products that could be more attractive to children because of their added chocolate, cacao, berry and fruit content. DNA was extracted and amplification of was performed using a commercial PCR kit.
Overall positivity was 60.56%. Domestic products were positive more often (60.96%) than foreign ones (57.69%). Only 26.67% of unpasteurised Latvian cow's milk samples were positive whereas 76.47% of pasteurised equivalents and 63.13% of fermented milk products were. Sweetened and fruit-containing samples were 71.43% positive.
The shedding of milk should be monitored and only milk from healthy animals allowed for sale for direct human consumption without pasteurisation. Raw milk quality and the effectiveness of industrial heat treatment and pasteurisation methods in Latvia and other countries should be carefully assessed to ensure adequate consumer health protection.
自2012年以来，拉脱维亚一直在对奶牛中的Q热进行调查。2015年，10.7%的农场的大罐牛奶中检测到其病原体伯氏考克斯氏体的DNA呈阳性。几个国家已经对乳制品中伯氏考克斯氏体DNA和传染性细菌的存在情况进行了评估，由于拉脱维亚的牛奶可能含有这些物质，因此建议在该国进行平行评估。因此，本研究对来自拉脱维亚的商店和农场零售乳制品进行了检测，并纳入了外国产品进行比较。
对来自41家拉脱维亚牛奶生产商的187份各类乳制品样本进行了调查。还纳入了从爱沙尼亚、法国、德国、希腊、意大利、立陶宛、荷兰、波兰和西班牙收集的26份可比样本。所有国家的发酵乳制品总数为160份。特别关注那些因添加了巧克力、可可、浆果和水果成分而可能对儿童更具吸引力的产品。提取DNA并使用商业PCR试剂盒进行伯氏考克斯氏体的扩增。
总体阳性率为60.56%。国内产品的阳性率（60.96%）高于国外产品（57.69%）。拉脱维亚未经过巴氏杀菌的牛奶样本中只有26.67%呈阳性，而经过巴氏杀菌的同类样本中有76.47%呈阳性，发酵乳制品中有63.13%呈阳性。加糖和含水果的样本阳性率为71.43%。
应监测牛奶中伯氏考克斯氏体的脱落情况，只有来自健康动物的牛奶未经巴氏杀菌即可直接供人类食用。应仔细评估拉脱维亚和其他国家的生牛奶质量以及工业热处理和巴氏杀菌方法的有效性，以确保充分保护消费者健康。
