短螺旋体是革兰氏阴性的,在许多动物的肠道中定居的厌氧细菌,包括家禽。在家禽中,短螺旋体物种可以是共生的(B.无辜的人,B.murdochii,\'B.pulli\')或致病性(B.pilosicoli,B.中间媒体,B.alvinipulli或很少见B.hyodysenteriae),后者引起禽肠螺旋体病(AIS)。抗菌治疗的选择是有限的,经常涉及截短侧耳素的管理,tiamulin,在水中。在这项研究中,来自英国鸡的38个短螺旋体分离株,代表共生和致病物种,进行全基因组测序以鉴定抗菌素耐药性(AMR)机制,并确定对许多抗菌素的最低抑制浓度(MIC)。我们在pilosicoli和pulli分离株中鉴定了blaOXA的几种新变体,和tva的变化导致了B.murdochii和B.pulli的两个新的tva变体。许多分离株还具有已知在16S和23SrRNA基因中编码AMR的突变。基因型多药耐药(MDR)的分离株百分比为16%,最常见的耐药性是:四环素,截短侧耳素和β-内酰胺,在三B中发现的pulli\'和一个B.pilosicoli。与基因型和相应的抗生素MIC表型有良好的相关性:胸膜木素(tiamulin和valnemulin),大环内酯类(泰乐菌素和tylvalosin),林可霉素和多西环素.在致病性短螺旋体中,本研究中确定的抗性决定因素的发生,尤其是那些MDR,可能会影响AIS的治疗和农场感染的清除。
Brachyspira species are Gram negative, anaerobic bacteria that colonise the gut of many animals, including poultry. In poultry, Brachyspira species can be commensal (B. innocens, B. murdochii, \'B. pulli\') or pathogenic (B. pilosicoli, B. intermedia, B. alvinipulli or rarely B. hyodysenteriae), the latter causing avian intestinal spirochaetosis (AIS). Antimicrobial therapy options for treatment is limited, frequently involving administration of the pleuromutilin, tiamulin, in water. In this study 38 Brachyspira isolates from chickens in the UK, representing both commensal and pathogenic species, were whole genome sequenced to identify antimicrobial resistance (AMR) mechanisms and the minimum inhibitory concentration (MIC) to a number of antimicrobials was also determined. We identified several new variants of blaOXA in B. pilosicoli and B. pulli isolates, and variations in tva which led to two new tva variants in B.murdochii and B.pulli. A number of isolates also harboured mutations known to encode AMR in the 16S and 23S rRNA genes. The percentage of isolates that were genotypically multi-drug resistance (MDR) was 16%, with the most common resistance profile being: tetracycline, pleuromutilin and beta-lactam, which were found in three \'B. pulli\' and one B. pilosicoli. There was good correlation with the genotype and the corresponding antibiotic MIC phenotypes:
pleuromutilins (tiamulin and valnemulin), macrolides (tylosin and tylvalosin), lincomycin and doxycycline. The occurrence of resistance determinants identified in this study in pathogenic Brachyspira, especially those which were MDR, is likely to impact treatment of AIS and clearance of infections on farm.