Detection of Coxiella burnetii by Real-Time PCR in Raw Milk and Traditional Cheese Distributed in Tehran Province

Abstract

Coxiella burnetii is common causative agent of Q fever in humans and animals. Although the main route of human infection is through inhalation of contaminated aerosols (dust), but oral transmission through contaminated raw milk and dairy products are also possible routes of infection. The aim of this study was to identify and determine the extent of contamination and prevalence of Coxiella burnetii in raw milk and traditional unpacked cheese collected from distribution centers of Tehran province. In this study, 100 samples of raw milk and 40 samples of traditional unpacked cheese were collected from 4 districts of Tehran randomly and then the presence of Coxiella burnetii was assessed using Real–Time PCR method. Our findings indicated that 10 of 100 samples of raw milk were positive for Coxiella burnetii (10 percent) and the rest of them were negative and also 3 of 40 samples of traditional unpacked cheese were positive for Coxiella burnetii (7.5 percent) and the remaining samples were negative. The results of this study showed that bovine milk is one of the potential reservoirs of Coxiella burnetii. Regarding the expand distribution of raw milk all over Tehran, the control of the bacterium in these products for human health should be considered. In traditional unpacked cheeses with high rates of bacterial contamination, the products are another risk (hazard) factor for consumers. According to the results of this study, distribution of raw milk and traditional dairy products is high risk for human health. Therefore, it is important to inform consumers about the potential risks of unprocessed milk and advise them to avoid consumption of traditional milk products.