Genomic Detection of Coxiella Burnetii in Raw Cow, Sheep and Goat Milk Samples Using PCR Assay and Two Types of Primers in Mazandaran Province, Iran: A Preliminary Study

The aim of this study was to investigate prevalence of Coxiella burnetii in milk samples of dairy cow, sheep and goats using PCR method in Mazandaran Province, Iran.

From May 2018 to December 2018, a total of 200 raw milk samples of cows, sheep and goats were randomly collected from Mazandaran Province. These samples were tested for Coxiella burnetii using polymerase chain reaction assay with two various primers.

In this study, the aim was to investigate the prevalence of Coxiella burnetii using polymerase chain reaction by comparing two types of primers. Using Trans primer, a total of 19 samples [17 sheep milk samples (17.52%) and two cow milk samples (2.70%)] were positive for Coxiella burnetii while none of the goat milk samples were positive. Using the OMP primers, none of the samples were positive and the results showed that the Trans primer included a further ability to detect Coxiella burnetii. Prevalence of Coxiella burnetii was higher in autumn and winter than in other seasons (p < 0.05). The highest frequency of positive samples was linked to Joybar City with eight samples (66.67%) and the lowest frequency was linked to Mahmoud Abad with one sample (11.11%). The number of positive samples detected by Trans primers was 16 (8.60%) in the traditional unit and two (20%) in the semi-industrial unit. However, no positive samples were detected in industrial units. Moreover, the number of positive samples by Trans primers was 12 (12.90%) from the bulk tanks and seven (6.55%) from individual samples. Studying prevalence of contamination and risk factors reveals importance of the infection for health officials.

Results of this study showed that Trans- polymerase chain reaction method included a further ability to detect Coxiella burnetii infection. Prevalence of Coxiella burnetii varied in various seasons; hence, prevalence of Coxiella burnetii was higher in autumn and winter than in other seasons. For control and prevention, further studies on epidemiology of Coxiella burnetii from raw milks and prevalence of Q fever in the society are necessary.