PCR-RFLP of Coxiella burnetii Plasmids Isolated from Raw Milk Samples in Iran

Background and Aim: Several methods have been employed to identify Coxiella burnetii isolates based on the specific Coxiella burnetii QpH۱ plasmid to distinguish the acute form from the chronic form of Q fever disease in humans and animals owing to the presence of unique gene sequences in this plasmid. Therefore, the present study aimed to investigate the panel of nucleic acid fragments resulting from the enzymatic cleavage in the QpH۱ plasmid isolated from cow and buffalo milk by nested polymerase chain reaction (Nested-PCR). Materials and Methods: A total of ۸۶ isolates of Coxiella burnetii QpH۱ plasmid, which were confirmed by the Nested-PCR method in ۲۰۱۸, were used to determine the RFLP panel of the QpH۱ plasmid. Plasmids were first extracted with the kit and were then affected by the Hph۱ restriction enzyme. Additionally, ۴ nucleic acid samples were sent to Pishgam Company for sequencing with the IS۱۱۱۱ gene primer. Results: Based on the results of the PCR-RFLP test, all plasmid samples showed a similar two-fragment pattern under the influence of Hph۱. The results of the nucleic acid sequencing of all ۴ samples indicated that they had a Coxiella burnetii type (Nine Mile RSA۴۹۳ strain). Conclusion: RFLP patterns exhibited no difference on the Coxiella burnetii QpH۱ plasmid isolated from cow and buffalo milk. Hence, all isolates were genetically identical, and the infection in animals could originate from one Coxiella burnetii strain (Nine Mile RSA۴۹۳ strain).

کلیدواژه ها:

Buffalo ، Cattle ، Coxiell burnetii ، plasmid ، PCR-RFLP ، گاومیش ،  گاو ،  PCR-RFLP ،  کوکسیلا بورنتی ،  پلاسمید