Jacques B J, Bourret T J, Shaffer J J
Department of Biology, University of Nebraska at Kearney, 2401 11th Ave., Kearney, NE 68849.
Department of Medical Microbiology and Immunology, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178.
J Med Entomol. 2017 Nov 7;54(6):1712-1717. doi: 10.1093/jme/tjx124.
Flies are known to be mechanical vectors of bacterial, viral, and parasitic diseases. Although flies are known to transmit disease, the effects of cleaning behavior have not been well studied. This study quantified the cleaning effectiveness and behavior of three fly species: Sarcophaga bullata, Musca domestica L., and Drosophila virilis. Flies were transferred to plates of Escherichia coli or Pseudomonas aeruginosa and allowed to walk on the bacteria for a total of 5 min. After the flies were contaminated, they were either immediately collected to quantify bacteria or were placed onto sterile plates to clean for 5 or 10 min. After cleaning, flies were placed into tubes with 1 ml of sterile 0.85% saline and were gently shaken for 1 min to remove bacteria. A serial dilution was made and 50-µl spot titers were plated. Cleaning behavior was also monitored and scored for a period of 5 min. Results demonstrate a bacterial reduction for both bacteria on all three fly species. Sarcophaga bullata and D. virilis both showed a significant reduction of both bacteria within 10 min, whereas M. domestica only showed a significant reduction in P. aeruginosa. Cleaning behavior increased significantly in flies that were exposed to bacteria compared to flies that were not exposed to bacteria. This study is important, as it demonstrates that fly cleaning could affect mechanical transmission of disease, and additional studies should look at flies' abilities to remove other types of microorganisms.
众所周知，苍蝇是细菌、病毒和寄生虫病的机械传播媒介。尽管苍蝇会传播疾病，但清洁行为的影响尚未得到充分研究。本研究量化了三种苍蝇的清洁效果和行为：肉蝇、家蝇和果蝇。将苍蝇转移到含有大肠杆菌或铜绿假单胞菌的平板上，让它们在细菌上行走总共5分钟。苍蝇被污染后，要么立即收集以量化细菌数量，要么放在无菌平板上清洁5或10分钟。清洁后，将苍蝇放入装有1毫升无菌0.85%生理盐水的试管中，轻轻摇晃1分钟以去除细菌。进行连续稀释，并接种50微升的点滴效价。还对清洁行为进行了5分钟的监测和评分。结果表明，所有三种苍蝇携带的两种细菌数量都有所减少。肉蝇和果蝇在10分钟内两种细菌数量均显著减少，而家蝇仅在铜绿假单胞菌数量上显著减少。与未接触细菌的苍蝇相比，接触细菌的苍蝇清洁行为显著增加。这项研究很重要，因为它表明苍蝇的清洁行为可能会影响疾病的机械传播，并且更多研究应该关注苍蝇清除其他类型微生物的能力。
