PDF(Pubmed)
Abstract：
BACKGROUND: Acinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The bacteria is a zoonotic and opportunistic pathogen that causes various infections, including nosocomial infections. The aim of this study was to identify A. lwoffii strains isolated from bovine milk with subclinical mastitis in China and get a better understanding of its antimicrobial susceptibility and resistance profile. This is the first study to analyze the drug resistance spectrum and corresponding mechanisms of A. lwoffii isolated in raw milk.
RESULTS: Four A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol.
CONCLUSIONS: These findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.
RESULTS: Four A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol.
CONCLUSIONS: These findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.
摘要：
背景：不动杆菌（A.lwoffii)是环境中常见的革兰氏阴性细菌，它是人体呼吸道和消化道中的正常菌群。这种细菌是一种人畜共患和机会性病原体，会导致各种感染，包括医院感染。本研究的目的是鉴定从中国患有亚临床乳腺炎的牛乳中分离的A.lwoffii菌株，并更好地了解其抗菌敏感性和耐药性。这是首次分析原料乳中分离的A.lwoffii的耐药谱和相应机制的研究。
结果：通过PCR方法分离出4株A.lwoffii菌株。使用邻居连接方法进行的遗传进化分析表明，这四个菌株与不动杆菌具有很高的同源性。这些菌株对几种抗生素具有抗性，并在它们身上携带17种耐药基因。具体来说,在23种抗生素中，这些菌株对6种抗生素完全敏感，包括强力霉素,红霉素,多粘菌素,克林霉素,亚胺培南,还有美罗培南.此外,菌株表现出可变的抗性模式。共有17个抗性基因，包括质粒介导的抗性基因，在四个菌株中检测到。这些基因介导了对5类抗微生物药物的抗性，包括β-内酰胺,氨基糖苷类,氟喹诺酮类药物,四环素,磺胺类药物,和氯霉素.
结论：这些发现表明，患有亚临床乳腺炎的牛的原料乳中存在多药耐药的鲍氏不动杆菌菌株。不动杆菌广泛存在于自然环境样本中,包括水,土壤,浴缸,肥皂盒,皮肤,咽部,结膜,唾液,胃肠道,还有阴道分泌物.菌株在移动遗传元件中携带抗性基因以增强这些基因的传播。因此,应更加重视流行病学监测和耐药A.lwoffii。
结果：通过PCR方法分离出4株A.lwoffii菌株。使用邻居连接方法进行的遗传进化分析表明，这四个菌株与不动杆菌具有很高的同源性。这些菌株对几种抗生素具有抗性，并在它们身上携带17种耐药基因。具体来说,在23种抗生素中，这些菌株对6种抗生素完全敏感，包括强力霉素,红霉素,多粘菌素,克林霉素,亚胺培南,还有美罗培南.此外,菌株表现出可变的抗性模式。共有17个抗性基因，包括质粒介导的抗性基因，在四个菌株中检测到。这些基因介导了对5类抗微生物药物的抗性，包括β-内酰胺,氨基糖苷类,氟喹诺酮类药物,四环素,磺胺类药物,和氯霉素.
结论：这些发现表明，患有亚临床乳腺炎的牛的原料乳中存在多药耐药的鲍氏不动杆菌菌株。不动杆菌广泛存在于自然环境样本中,包括水,土壤,浴缸,肥皂盒,皮肤,咽部,结膜,唾液,胃肠道,还有阴道分泌物.菌株在移动遗传元件中携带抗性基因以增强这些基因的传播。因此,应更加重视流行病学监测和耐药A.lwoffii。
