【摘要】：鴨疫里氏桿菌感染具有發(fā)病率高、死亡率高的特點(diǎn),是目前引起世界范圍內(nèi)水禽感染的重要疾病,同時(shí)也是造成養(yǎng)鴨業(yè)經(jīng)濟(jì)損失的主要疾病之一。由于鴨疫里氏桿菌極易產(chǎn)生耐藥性,因此給臨床治療帶來(lái)了極大的困擾。目前關(guān)于鴨疫里氏桿菌耐藥性的研究報(bào)道還比較少,尤其是關(guān)于分子耐藥機(jī)制和傳播機(jī)制的研究鮮有報(bào)道。2013年2月至2015年7月,從廣東省9個(gè)地區(qū)收集具有典型鴨疫里氏桿菌病癥狀的病(死)鴨和鵝的腦、肝組織樣品,分離培養(yǎng)鴨疫里氏桿菌。采用特異性PCR方法進(jìn)行分子學(xué)鑒定,同時(shí)采用全自動(dòng)微生物鑒定儀來(lái)鑒定疑似菌株,共分離得到115株鴨疫里氏桿菌,其中鴨源54株,鵝源61株。用瓊脂二倍稀釋法測(cè)定32種抗菌藥物的敏感性。藥敏結(jié)果顯示,分離株有很高的耐藥性,有103株(89.6%)鴨疫里氏桿菌分離株存在多重耐藥現(xiàn)象。采用PCR和測(cè)序方法對(duì)115株分離菌進(jìn)行了耐藥基因和整合子類(lèi)型檢測(cè)和分析。結(jié)果顯示:共有5大類(lèi)抗生素的25種耐藥基因被檢測(cè)出來(lái)。在鴨疫里氏桿菌分離株中首次檢測(cè)出三種氨基糖苷磷酸轉(zhuǎn)移酶基因aph(3’)-Ⅱ、aph(3’)-Ⅳ、aph(4’)-Ⅰa,氨基糖苷轉(zhuǎn)移酶基因aad B,紅霉素耐藥基因erm B、erm C和磺胺類(lèi)抗菌藥物耐藥的sul3。9株鴨疫里氏桿菌株含有1類(lèi)整合子,其中6株攜帶978bp大小的aad A2基因盒和3株攜帶2287bp大小的aac(6’)-Ⅱ-cat B3-aad A1基因盒。對(duì)分離得到的菌株進(jìn)行Sma I-PFGE分子分型,共有58株分型成功,得到16種不同的Sma I-PFGE型(以相似度≥90%為判定標(biāo)準(zhǔn)),包括11個(gè)簇和5個(gè)單一型。本研究中的鴨疫里氏桿菌分離株存在廣泛的克隆傳播,且克隆傳播存在于不同種屬的宿主動(dòng)物(鴨和鵝)間及相同、不同地區(qū)間分離到的菌株中。為探究抗生素耐藥性與生物膜的相關(guān)性,用結(jié)晶紫染色的方法定量測(cè)定生物膜形成能力。結(jié)果表明,有95(82.6%)株鴨疫里氏桿菌分離株具有產(chǎn)膜能力,其中40(34.8%)株是強(qiáng)產(chǎn)膜菌株,且對(duì)12~23種抗菌藥物具有抗藥性;25(21.7%)中等產(chǎn)膜株和30(26.1%)弱產(chǎn)膜菌株可對(duì)7~12種種抗菌藥物耐藥。20(17.4%)株沒(méi)有產(chǎn)膜能力,耐藥種數(shù)小于等于6種。可以看出生物膜形成能力與耐藥譜的種數(shù)之間存在一定的關(guān)系。此外,通過(guò)S1-PFGE和雜交的方法確定鴨疫里氏桿菌中flo R基因既位于染色體上也位于質(zhì)粒上,發(fā)現(xiàn)在13株鴨疫里氏桿菌中存在一個(gè)新型攜帶flo R基因的質(zhì)粒,其大小23kb,與之前的報(bào)道的質(zhì)粒不同。通過(guò)接合轉(zhuǎn)移和質(zhì)粒穩(wěn)定性實(shí)驗(yàn)等方法證明這個(gè)新型質(zhì)�？梢赞D(zhuǎn)移到與之不同種屬的大腸桿菌工程菌C600中,轉(zhuǎn)移頻率為10~(-6)~10~(-9),但是穩(wěn)定性很差。
[Abstract]:Richter Duck infection is an important disease that causes worldwide waterfowl infection with high incidence and high mortality. It is also one of the major diseases that cause economic losses in duck industry. It is very difficult for the clinical treatment because of the resistance of Ribrella canalicus to drug resistance. At present, there are few reports on drug resistance of Rim Duck, especially on the mechanism of molecular resistance and transmission. From February 2013 to July 2015, The brain and liver tissue samples of dead ducks and geese with typical symptoms of Ribrella duck were collected from 9 regions of Guangdong Province and isolated and cultured. The molecular identification was carried out by specific PCR, and the suspected strains were identified by automatic microbiological identification instrument. A total of 115 strains of Riemiella Duck were isolated, of which 54 were from ducks and 61 from geese. The sensitivity of 32 antimicrobial agents was determined by Agar double dilution method. The results of antimicrobial susceptibility showed that the isolates had high drug resistance and 103 strains (89.6%) had multiple drug resistance. The resistance genes and integron types of 115 isolates were detected and analyzed by PCR and sequencing. The results showed that a total of 25 resistant genes of 5 major antibiotics were detected. Three aminoglycoside phosphotransferase gene aph (3')-鈪，

本文編號(hào)：2131153