Enterococcus faecalis OG1RF:pMV158 Survives and Proliferates in the House Fly Digestive Tract
Enterococcus faecalis OG1RF:pMV158 Survives and Proliferates in the House Fly Digestive Tract
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DOI：
10.1603/me11167
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发表时间：
2012-01-01
影响因子：
2.1
通讯作者：
Zurek, L.
中科院分区：
文献类型：
--
作者：
Doud, C. W.;Zurek, L.
粪肠球菌是一种重要的医院病原体，家蝇与这种细菌的传播有关。本研究以表达GFP的E.粪肠球菌OG1RF：pMV 158用于追踪细菌在家蝇消化道中的命运，以评估该昆虫作为E.粪便。菌落形成单位（CFU）计数来自活的荧光大肠杆菌。在细菌暴露后1、4、8、24、48、72和96 h，从口器和消化道区域（唇瓣、前肠、中肠和后肠）回收粪便。中肠中的细菌计数在1 h和4 h时显著最高，并在前24 h内下降。在唇瓣中，E.粪便浓度在前24小时内较低，然后大幅增加。在紫外线显微镜下对消化道进行细菌计数和直接观察。粪便在48小时后在作物中达到峰值，并保持高水平直到实验结束。浓度E.与消化道的其他部分相比，后肠中的粪便含量较低。显微镜和CFU计数表明E.粪便在中肠中被消化，但在作物中增殖。在测定结束时（96小时）取样的饮用水和饲料（玉米片）均被荧光E. faecalis，证明蝇类传播E.粪便。我们的数据支持这一观点，即家蝇可以作为细菌的生物增强载体。
Enterococcus faecalis is an important nosocomial pathogen and house flies have been implicated in the dissemination of this bacterium. In this study, GFP-expressing E. faecalis OG1RF:pMV158 was used to track the fate of the bacterium in the digestive tract of the house fly, Musca domestica (L) to assess the vector potential of this insect for E. faecalis. Colony forming unit (CFU) counts were obtained from viable fluorescing E. faecalis recovered from mouthparts and digestive tract regions (labelum, foregut, midgut, and hindgut) at 1, 4, 8, 24, 48, 72, and 96 h after the bacterial exposure. Bacterial counts were significantly highest in the midgut at 1 h and 4 h and declined during the first 24 h. In the labelum, E. faecalis concentrations were low within the first 24 h and then greatly increased. Bacterial counts and direct observations of the digestive tract under a dissecting microscope with ultra violet light revealed that E. faecalis peaked in the crop after 48 h and remained high until the end of the experiment. Concentrations of E. faecalis in the hindgut were low when compared with other parts of the digestive tract. Microscopy and CFU counts suggest that E. faecalis was digested in the midgut but proliferated in the crop. Both drinking water and feed (flaked corn) sampled at the end of the assay (96 h) were contaminated by fluorescing E. faecalis, demonstrating that the flies disseminated E. faecalis. Our data support the notion that house flies can act as a bioenhanced vector for bacteria.