Presence of Coxiella burnetii in blood, milk, and cheese samples from sheep farms in Northeast Anatolia, Turkey
Abstract
Coxiella burnetii is a zoonotic bacterial pathogen responsible for causing Q fever in humans. It is commonly found in livestock, particularly sheep, posing a potential risk of transmission to humans through various sources. Understanding the prevalence of C. burnetii in different matrices, such as blood, milk, and cheese, is essential for evaluating the potential public health implications. This study aimed to determine the prevalence of C. burnetii in blood, milk, and cheese samples obtained from sheep farms in Northeast Anatolia, Turkey, and investigated the effects of C. burnetii-positive cheese samples on pH, water activity (aw), and fat and salt percentages. A total of 271 blood, 271 milk, and 90 cheese samples were collected from 23 sheep farms in the study region. The presence of C. burnetii was assessed using serological and molecular techniques. Antibodies against C. burnetii were detected in 24.3% (66/271) of blood samples and 12.2% (33/271) of milk samples, indicating exposure to the pathogen. However, the DNA of C. burnetii was not detected in either the blood or milk samples. In contrast, 5.6% (5/90) of the Turkish white brined cheese samples tested positive for C. burnetii. The pH values of the positive and negative samples did not significantly differ (p > 0.05), with mean values of 5.07 ± 0.38 and 5.18 ± 0.79, respectively. However, a statistically significant difference (p < 0.05) was observed in the fat percentages between positive (22.4 ± 3.44%) and negative (28.5 ± 11.57%) cheese samples. No significant differences were found in the aw and salt percentages between the positive and negative cheese samples. This study presents the first molecular evidence of C. burnetii in Turkish white brined cheese, highlighting the potential contamination of this popular dairy product. These findings underscore the importance of implementing effective control measures in sheep farming and dairy production to minimize the risk of C. burnetii transmission to humans. Further studies are warranted to investigate the sources, routes, and potential public health implications of C. burnetii in dairy products and its role in the epidemiology of Q fever in Turkey.
