| 摘要: |
| 【目的】了解宁夏地区奶牛正常乳汁和患乳腺炎乳汁中肠球菌的分布规律及其耐药特征，为宁夏地区奶牛乳腺炎疾病的抗菌药物合理使用提供参考。【方法】对宁夏地区16个规模化奶牛养殖场近3年来1 154份乳汁样品（正常乳汁383份，患乳腺炎乳汁771份）进行肠球菌分离，采用形态学观察和生化试验对分离所获的496株肠球菌进行鉴定，通过K-B药敏纸片扩散法测定分离肠球菌菌株对青霉素（PG）、头孢唑林（CFZ）、庆大霉素（GEN）、四环素（TET）、红霉素（EM）、林可霉素（LCM）、链霉素（SM）和万古霉素（VCA）等8种药物的敏感性，并使用PCR方法对分离肠球菌菌株进行四环素类药物耐药基因（tetA、tetB、tetC、tetM）、大环内酯类药物耐药基因（mecA、ermA、ermB、ermC）以及林可胺类药物耐药基因（lsaA、lsaE、lnuG、lnuA）检测。【结果】从1 154份乳样中共分离得到496株肠球菌，经鉴定分属6种肠球菌，分别是屎肠球菌、海氏肠球菌、粪肠球菌、蒙氏肠球菌、耐久肠球菌和鹑鸡肠球菌。其中屎肠球菌305株，占分离菌株总数的61.5%；海氏肠球菌124株，占分离菌株总数的25.0%；粪肠球菌27株，占分离菌株总数的5.4%；蒙氏肠球菌21株，占分离菌株总数的4.2%；耐久肠球菌15株，占分离菌株总数的3.0%；鹑鸡肠球菌4株，占分离菌株总数的0.8%。临床分离菌株对林可霉素、四环素、红霉素的耐药率分别达到95.8%，82.7%和80.2%，尤以耐7种药物的菌株为主，达230株 (占耐药菌株的46.4%) ，最常见的耐药谱为PG+CFZ+GEN+TET+EM+LCM+SM。正常乳汁中分离的菌株主要为海氏肠球菌(检出率为73.8%)，对林可霉素的耐药率最高（94.5%）；患乳腺炎乳汁中分离的菌株主要为屎肠球菌(检出率为89.5%)，对四环素的耐药率最高（97.0%）。496株临床肠球菌中有488株检测出携带耐药基因，检出率为98.4%；检测出乳源肠球菌不携带tetA、tetB、tetC、mecA、lnuG和lnuA耐药基因；携带ermA、ermB、ermC、tetM、lsaA和lsaE耐药基因，其携带率分别为51.0%，80.3%，33.2%，88.1%，41.6%和74.4%；最常见耐药基因谱为ermA+ermB+tetM+lsaE+lsaA。【结论】宁夏地区奶牛乳汁中肠球菌耐药性严重，且具有多重耐药性特征，给公共卫生带来潜在危害，应引起高度重视。 |
| 关键词: 肠球菌 奶牛乳汁 耐药性分析 耐药基因 宁夏地区 |
| DOI：10.13207/j.cnki.jnwafu.2024.08.001 |
| 分类号: |
| 基金项目:宁夏回族自治区科技攻关（支撑）计划项目(2021BEF02021)；宁夏回族自治区科技创新领军人才培育项目（2021G-KLRLX10）；国家自然科学基金地区科学基金项目（32060816） |
|
| Antibiotic resistance of bovine milk derived Enterococcus in Ningxia |
|
QIAO Yarui1,2, YANG Jiangliu1,2, GAO Dengjun3, FU Nana1,2, ZHOU Xuezhang1,2
|
|
1.College of Life Sciences,Ningxia University,Yinchuan，Ningxia 750021，China;2 Key Laboratory of Conservation and Utilization of Biological Resources with Western Characteristics,Ministry of Education,Yinchuan,Ningxia 750021,China;3.Inner Mongolia Autonomous Region Center for Animal Disease Prevention and Control,Huhhot,Inner Mongolia 750300,China
|
| Abstract: |
| 【Objective】This study investigated the dissemination and resistance patterns of Enterococcus in milk of both regular and mastitic cow in Ningxia to offer guidance for the judicious administration of antibiotics in cow mastitis treatment.【Method】In the past three years,1 154 milk samples (383 normal milk and 771 mastitic milk) from 16 large-scale dairy farms in Ningxia were isolated,and the obtained 496 Enterococcus isolates were identified by morphological observation and biochemical experiments.The K-B susceptibility paper method was used to identify the sensitivity to penicillin (PG),cefazolin (CFZ),gentamicin (GEN),tetracycline (TET),erythromycin (EM),lincomycin (LCM),streptomycin (SM) and vancomycin (VCA),and PCR was used to detect resistance genes including tetracycline (tetA,tetB,tetC,and tetM),macrolide (mecA,ermA,ermB,and ermC),and lincomamide (lsaA, lsaE,lnuG,and lnuA).【Result】A total of 496 strains of enterococci were isolated from 1 154 milk samples,and they were identified as 6 species including Enterococcus faecium,Enterococcus hirae,Enterococcus faecalis,Enterococcus mundtii,Enterococcus durans and Enterococcus gallinarum.Among them,305 Enterococcus faeciums strains accounted for 61.5% of total isolated strains,124 Enterococcus hiraes strains accounted for 25.0%,27 Enterococcus faecalis strains accounted for 5.4%,21 Enterococcus mundtii strains accounted for 4.2%,15 Enterococcus durans strains accounted for 3.0%,and 4 Enterococcus gallinarum strains accounted for 0.8%.The resistance rates of clinically isolated strains to lincomycin,tetracycline and erythromycin were 95.8%,82.7% and 80.2%,respectively.The number of 7 resistant strains was 230 (46.4% of resistant strains),and the most common resistance spectrum was PG+CFZ+GEN+TET+EM+LCM+SM.The main isolated strain in normal milk was Enterococcus hiraes with detection rate of 73.8%,and it had the highest resistance rate to linkamides (94.5%).The main isolated strain from mastitis milk was Enterococcus faeciums (detection rate of 89.5%),with the highest resistance rate to tetracycline (97.0%).Among the 496 clinical enterococci strains,488 were detected with drug resistant genes,with a detection rate of 98.4%.It was found that lactogenic Enterococcus did not carry tetA,tetB,tetC,mecA,lnuG and lnuA resistance genes.Their carrying rates were 51.0%,80.3%,33.2%,88.1%,41.6% and 74.4%,respectively,and the most common resistance gene profile was ermA+ermB+tetM+lsaE+lsaA.【Conclusion】The antibiotic resistance of Enterococcus in milk of dairy cows in Ningxia was high with the characteristic of multi-drug resistance.More attention should be paid to the potential harm to the public. |
| Key words: Enterococcus bovine milk antimicrobial resistance analysis drug resistance genes Ningxia area |
