Moro Claire Valiente, Fravalo Philippe, Amelot Michel, Chauve Claude, Zenner Lionel, Salvat Gilles
UMR 958 ENVL/INRA Protozoaires Entéricoles et Parasites des Volailles, Ecole Nationale Vétérinaire de Lyon, Marcy l'Etoile, France.
Avian Pathol. 2007 Aug;36(4):307-11. doi: 10.1080/03079450701460484.
The poultry red mite (Dermanyssus gallinae) is the most important and common ectoparasite of laying hens in Europe. This haematophagous mite has been experimentally demonstrated to be a vector of Salmonella Enteritidis by acquiring bacteria through the blood meal or cuticular contact. We have evaluated another route of infection by orally inoculating chicks with mites previously infected by S. Enteritidis. Two methods of infecting the mites were tested: mites contaminated by cuticular contact or during the blood meal. After the washing of mites with paraformaldehyde, groups of 10 Salmonella-contaminated mites were inoculated individually into 1-day-old chicks. The titre of the inoculum suspension was evaluated by crushing mites and followed by bacteriological counting. It was 3x10(4) colony-forming units/chick and 2.7x10(6) colony-forming units/chick, respectively, for cuticular contact and orally mediated contamination of mites. Each bird was found to be positive 12 days post-inoculation. Salmonella colonized the intestinal tracts and invaded the livers and spleens. The caecal content concentration reached a mean level of S. Enteritidis of 8.5x10(4) most probable number (MPN) Salmonella/g. This experiment demonstrated the ability of mites to orally infect 1-day-old chicks with subsequent colonization and multiplication of Salmonella. Consequently, mites infected by S. Enteritidis constitute potential reservoir hosts of this bacterium, allowing it to persist in the poultry house as a source of infection for newly introduced animals. If contaminated mites are found in poultry facilities, effective red mite control should be performed before new batches are introduced into the facility.
禽刺螨（Dermanyssus gallinae）是欧洲产蛋母鸡最重要且最常见的体外寄生虫。这种吸血螨已通过实验证明，可通过血餐或表皮接触获取细菌，从而成为肠炎沙门氏菌的传播媒介。我们通过给雏鸡口服先前感染了肠炎沙门氏菌的螨，评估了另一种感染途径。测试了两种感染螨的方法：表皮接触污染螨或在血餐期间污染螨。在用多聚甲醛清洗螨后，将每组10只受沙门氏菌污染的螨分别接种到1日龄雏鸡体内。通过碾碎螨并随后进行细菌计数来评估接种物悬液的滴度。对于表皮接触污染螨和经口介导污染螨，滴度分别为3×10⁴菌落形成单位/只雏鸡和2.7×10⁶菌落形成单位/只雏鸡。在接种后12天发现每只鸡均呈阳性。沙门氏菌在肠道定植并侵入肝脏和脾脏。盲肠内容物中肠炎沙门氏菌的浓度平均达到8.5×10⁴最可能数（MPN）沙门氏菌/克。该实验证明螨能够经口感染1日龄雏鸡，并使沙门氏菌随后定植和繁殖。因此，感染了肠炎沙门氏菌的螨构成了这种细菌的潜在储存宿主，使其能够在家禽舍中持续存在，作为新引入动物的感染源。如果在家禽设施中发现受污染的螨，在新一批家禽引入该设施之前应进行有效的红螨控制。
