Molecular Analysis of the Presence of Wolbachia in Indigenous Human Louse Populations in Iran

Introduction: Human lice infestation continues to be a public health challenge. Head lice not only cause physical irritation, but also lead to social and psychological problems. Body lice are vectors of several infectious diseases. While chemical control remains the mainstay of management, increasing insecticide resistance highlights the need for alternative strategies. Investigating endosymbiotic bacteria such as Wolbachia may provide new ways to control lice populations. Methods: Samples were collected from volunteers in four provinces of Iran. DNA extraction was performed according to the manufacturer’s instructions with minor adjustments to improve results. The presence of Wolbachia was assessed using PCR and nested-PCR methods targeting the Wolbachia surface protein (wsp), glutamyl-tRNA amidotransferase B subunit (gatB), and cytochrome oxidase subunit 1 (coxA) genes. DNA isolated from Wolbachia-infected Culex mosquitoes was used as a positive control to confirm the effectiveness of the assay. Distilled deionized water was also used as a negative control to ensure no contamination or false positives. Results: No Wolbachia DNA was found in any of the lice samples when the results were compared to the positive control. Amplification using the wsp, gatB, and coxA primer sets did not show any positive results in PCR or nested-PCR assays. Conclusion: The absence of detectable Wolbachia in the louse samples of this study may be due to genetic variation in the primer binding regions or low bacterial density. Further molecular investigations using other markers and optimized primers are recommended to clarify the possible presence of Wolbachia in Iranian louse populations.