摘要

苍蝇有能力在不同的环境中转移病原体，成为世界范围内人类疾病最重要的传播媒介之一。在这项研究中，我们在大学校园里捕获了苍蝇，并测试了它们针对粘菌素的移动抗性基因，这是人类药物中用于治疗由耐多药的革兰氏阴性细菌引起的临床感染的最后一种抗生素。我们开发的定量PCR检测表明，家蝇（86/252）和51.1％的原虫属terraenovae（23/45）分离株mcr-1基因阳性，家蝇占1.2％（3/252）和2.2％的P. terraenovae（2.2％，1/45）分离株mcr-2阳性，5.2％的家蝇（13/252）和44.4％的P. terraenovae（20/45）分离株阳性MCR-3。总体而言，从苍蝇中分离出的细菌的4.8％（9/189）对于mcr-1基因为阳性（大肠杆菌：8.3％，4/48;阴沟肠杆菌：12.5％，1/8;普罗威登斯alcalifaciens：11.8％ 2/17; Providencia stuartii：4.9％，2/41），而mcr-2和mcr-3都没有阳性。来自捕获在垃圾箱附近的吹蝇的四个mcr-1阳性分离株（两个P.startii和两个P.alcalifaciens）对粘菌素的MIC高于4mg / ml。这项研究报告了Providencia spp中的mcr-1运输。并在比利时和中国分别检测出mcr-2和mcr-3。这项研究表明，苍蝇可能会显着促进细菌的传播，将这些基因携带到各种各样的生态位。进一步的研究有必要探讨苍蝇在粘菌素耐药基因传播中可能发挥的作用。

Flies have the capacity to transfer pathogens between different environments, acting as one of the most important vectors of human diseases worldwide. In this study, we trapped flies on a university campus and tested them for mobile resistance genes against colistin, a last-resort antibiotic in human medicine for treating clinical infections caused by multidrug-resistant Gram-negative bacteria. Quantitative PCR assays we developed showed that 34.1% of Musca domestica(86/252) and 51.1% of Protophormia terraenovae (23/45) isolates were positive for the mcr-1 gene, 1.2% of M. domestica (3/252) and 2.2% of P. terraenovae (2.2%, 1/45) isolates were positive for mcr-2, and 5.2% of M. domestica (13/252) and 44.4% of P. terraenovae (20/45) isolates were positive for mcr-3. Overall, 4.8% (9/189) of bacteria isolated from the flies were positive for the mcr-1 gene (Escherichia coli: 8.3%, 4/48; Enterobacter cloacae: 12.5%, 1/8; Providencia alcalifaciens: 11.8%, 2/17; Providencia stuartii: 4.9%, 2/41), while none were positive for mcr-2 and mcr-3. Four mcr-1-positive isolates (two P. stuartii and twoP. alcalifaciens) from blow flies trapped near a dumpster had a MIC for colistin above 4 mg/ml. This study reports mcr-1 carriage in Providencia spp. and detection of mcr-2 and mcr-3 after their initial identification in Belgium and China, respectively. This study suggests that flies might contribute significantly to the dissemination of bacteria, carrying these genes into a large variety of ecological niches. Further studies are warranted to explore the roles that flies might play in the spread of colistin resistance genes.

http://aem.asm.org/content/84/1/e01736-17.short