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1.
为调查犬源大肠杆菌氨基糖苷类药物4种耐药基因的携带情况,探讨氨基糖苷类耐药表型与耐药基因的相关性,本试验选用氨基糖苷类代表药物庆大霉素、阿米卡星、大观霉素和妥布霉素进行药敏试验,参照相关文献用已建立的检测氨基糖苷类4种主要耐药基因的PCR方法对分离鉴定的156株犬源大肠杆菌进行分子检测。随机选取4种耐药基因阳性进行克隆测序并对药敏试验结果和耐药基因检测结果进行比较分析。结果显示,犬源大肠杆菌对庆大霉素、妥布霉素、大观霉素和阿米卡星的耐药率分别为55.8%、32.7%、25.0%和20.5%;所检大肠杆菌4种耐药基因aacC2、aphA3、aadA和aacC4的检出率依次为55.8%、26.3%、23.1%和9.0%。两株携带4种耐药基因,8株携带了3种耐药基因,携带两种或两种以上耐药基因菌株数占总菌株的40.4%(63/156)。序列分析结果表明,犬源大肠杆菌扩增产物与GenBank中的相应序列同源性较高。犬源大肠杆菌氨基糖苷类耐药基因以aacC2为主,耐药率与耐药基因的符合率基本呈正相关。 相似文献
2.
山东地区禽源致病性大肠杆菌氨基糖苷类药物耐药性及耐药基因的检测 总被引：3，自引：0，他引：3
采用K-B纸片法对224株大肠杆菌进行5种氨基糖苷类药物的药敏试验,采用微量肉汤稀释法进行庆大霉素和阿米卡星最低抑菌浓度（MIC）的测定,三重PCR法检测全部菌株氨基糖苷类钝化酶基因ant（3’’）-Ia、aac（6’）-Ib和aph（3’）-Ⅱa,普通PCR法检测16S甲基化酶基因。结果显示：山东省禽源大肠杆菌对链霉素、庆大霉素、卡那霉素、新霉素和阿米卡星的耐药率分别为84.4%、57.1%、55.8%、46.9%和40.2%;3种钝化酶基因ant（3’’）-Ia、aac（6’）和Ib、aph（3’）-Ⅱa的检出率依次为49.6%、25.0%和22.8%,介导高水平耐药的16S甲基化酶基因RmtB的检出率为11.6%（26/224）,只有1株大肠杆菌检测到armA基因,没有检测到rmtA,且3种甲基化酶基因在低度耐药菌中检出率均为0;所检大肠杆菌中携带2种及2种以上耐药基因的菌株占33.5%（75/224）,有1株大肠杆菌同时携带4种耐药基因。结果表明,氨基糖苷类钝化酶及16S甲基化酶广泛存在于禽源大肠杆菌菌中,其耐药性与相关耐药基因的检出率基本呈正相关,部分菌株的耐药性与耐药基因的检出率不一致,表明还存在其他耐药机制。 相似文献
3.
猪源大肠埃希菌药敏试验及耐药基因检测 总被引：2，自引：0，他引：2
为调查云南省某规模化猪场大肠埃希菌(E.coli)对氨基糖苷类药物的耐药性及耐药基因aadA1和aph(3′)的携带情况,采用K-B(Kirby-Bauer)法检测51株E.coli对6种氨基糖苷类抗生素的耐药性,同时对2个目的基因片段aph(3′)和aadA1进行PCR扩增。结果显示,51株猪E.coli对链霉素、新霉素、妥布霉素、庆大霉素、阿米卡星、卡那霉素的耐药率分别为49.0%、35.3%、47.1%、43.1%、15.7%及70.6%;利用PCR技术检测氨基糖苷类药物的相关耐药基因,其阳性检出率依次为aph(3′)(86.27%)和aadA1(54.90%)。结果表明,云南楚雄某猪场撒坝猪E.coli耐药性普遍存在,对氨基糖苷类抗生素存在多重耐药,其中以二重耐药为主,2个耐药基因检出率偏高。因此,猪场应该针对性选择用药,规范使用抗生素,从而延缓和减少耐药性的产生,促进社会公共卫生的发展。 相似文献
4.
为指导临床合理用药,根据耐药表型和基因型研究耐氨基糖苷类药物猪源大肠杆菌的流行情况,采用K—B法检测大肠杆菌对氨基糖苷类药物的耐药性,同时用PCR技术扩增氨基糖苷类药物的耐药基因以明确其基因型。结果显示,60株临床分离菌中,耐氨基糖苷类抗生素菌株54株,耐药率为90％;aac（3）-Ⅰ基因PCR扩增均为阴性;aac（3）-Ⅱ基因检出阳性28例,阳性率为46．7％;aac（6’）-Ⅰ基因检出阳性54例,阳性率为90％。结果表明,耐氨基糖苷类药物的大肠杆菌比较普遍,氨基糖苷类耐药基因以aac（3）-Ⅱ和aac（6’）-Ⅰ为主。 相似文献
5.
为了明确禽大肠埃希菌的耐药情况和氨基糖苷抗性基因的流行情况,用K-B纸片扩散法检测了27株致病性大肠杆菌对19种常用抗生素的耐药谱,用PCR方法检测了耐氨基糖苷抗生素分离株的4种氨基糖苷抗性基因,包括腺苷转移酶基因aadA1和aadB、乙酰转移酶基因aacA4 和磷酸转移酶基因apH(3')-Ⅱ.结果表明,氨苄青霉素、安灭菌、青霉素G和四环素的耐药菌株率高达100%,利福平的耐药菌株率达96.3%,氯霉素、红霉素的耐药菌株为70.4%,卡那霉素、环丙沙星、氟哌酸的耐药菌株率为59.3%, 链霉素的耐药菌株达到63.0%.氨苄西林/舒巴坦复方制剂、复达欣、庆大霉素和磷霉素的高敏菌株率分别为100%、 77. 8%、74.1%和51.9%.氨基糖苷抗性基因aadA1、aacA4 和apH(3')-Ⅱ的阳性率分别是44.4%、27.8%和55.6%,aadB未捡出.这些数据提示禽致病性大肠埃希菌存在广泛的耐药谱,氨基糖苷抗性基因aadA1和apH-(3')-Ⅱ是主要流行基因. 相似文献
6.
旨在调查鸭致病性大肠杆菌氨基糖苷修饰酶耐药基因(AMEs基因)的携带情况,探讨耐药基因与氨基糖苷类抗生素耐药表型的相关性。对98株鸭致病性大肠杆菌采用了K-B法,选用氨基糖苷类抗生素链霉素、新霉素、庆大霉素、阿米卡星、大观霉素和卡那霉素进行药敏试验,用建立的检测氨基糖苷类AMEs主要基因的四重PCR方法对上述菌株进行分子检测,并随机选取耐药基因ant(3″)-Ⅰa、aac(3)-Ⅱa和aph(3′)-Ⅱa各3个阳性扩增进行克隆测序,对药敏试验结果和基因检测结果进行比较分析。结果表明,98株鸭致病性大肠杆菌有67株对上述氨基糖苷类药物中的一种或多种耐药,耐药率为68.4%(67/98);有49株扩增出AMEs基因,AMEs基因的检出率为50%(49/98),其中ant(3″)-Ⅰa的检出率为30.6%(30/98),aac(3)-Ⅱa为13.3%(13/98),aph(3′)-Ⅱa为3.1%(3/98),ant(3″)-Ⅰa+aac(3)-Ⅱa为2.0%(2/98)、aac(3)-Ⅱa+aph(3′)-Ⅱa为1.0%(1/98),未检出aac(6′)-Ⅰb基因;序列分析结果表明,扩增产物与GenBank中的相应序列有很高的同源性(99%);AMEs耐药基因与耐药表型的符合率为73.1%(49/67),符合率从高到低依次为大观霉素60%(3/5)、庆大霉素55%(11/20)、链霉素33.3%(22/66)、卡那霉素19%(4/21)、新霉素12.5%(1/8)、阿米卡星0%(0/3)。另外有4株细菌检测到相关耐药基因但耐药表型为敏感,而有22株耐药表型为耐药却未检测到相关耐药基因。鸭致病性大肠杆菌氨基糖苷类耐药基因以ant(3″)-Ⅰa和aac(3)-Ⅱa两种为主,耐药性与相关耐药基因的检出率基本呈正相关。 相似文献
7.
目的为了解猪源大肠杆菌中Ⅰ型整合子的流行情况,探讨Ⅰ型整合子与大肠杆菌耐药表型的相关性。方法采用微量肉汤稀释法测定119株猪源大肠杆菌对8类14种抗菌药物的耐药性,并采用PCR法检测猪源大肠杆菌Ⅰ型整合酶基因(int I1)并扩增其可变区,对PCR产物进行酶切分析,测序分析整合子可变区携带的耐药基因盒。结果 119株大肠杆菌耐药现象十分严重,对四环素、磺胺异恶唑、新诺明全部耐药,所有菌株均呈多重耐药。119株猪源大肠杆菌中有92株含Ⅰ型整合子,检出率77.31%。扩增出7类大小不同的基因盒插入区片段,范围为1008bp～3149bp。7类Ⅰ型整合子在119株猪源大肠杆菌中存在13种流行组合。78.15%大肠杆菌菌株的Ⅰ型整合子携带2种或2种以上的基因盒,其中以携带编码氨基糖苷类药物耐药基因(aadA1、aadA2、aadA5、aadA22、aadB)最多,其次为编码磺胺类药物耐药基因(dfrA1、dfrA12、dfrA17、dfrA27),此外还携带编码利福平、林可霉素和氯霉素的基因lnuF、cmlA6、aar-3、orf。结论Ⅰ型整合子普遍存在于大肠杆菌中,且呈流行上升趋势;Ⅰ型整合子参与耐药及多重耐药,但单株细菌携带的耐药基因盒与其耐药表型无对应关系。 相似文献
8.
食品动物源大肠杆菌多重耐药菌株整合子-基因盒的分子特征 总被引：1，自引：0，他引：1
为研究分离自四川省食品动物源大肠杆菌多重耐药菌株整合子-基因盒分布及分子特征,采用多重PCR方法检测327株多重耐药菌株中I、Ⅱ、Ⅲ型整合酶基因,用PCR-测序法对整合子阳性菌进行基因盒序列分析.结果表明327株Escherichia coli中294株(89.91%)检出有I型整合子,未检出Ⅱ、Ⅲ型整合子.在随机选取的81株l型整合子阳性菌中,67株(82.72%)能扩增出800～3000 bp的耐药基因盒插入区.基因盒以编码对甲氧磺胺嘧啶类和氨基糖苷类药物耐药的dfrA、dhfrI和aadA基因家族为主,尤其以dfrA17+aadA5为优势基因盒.分别在2株菌中检出aacA4+catB3+dfrA1和aadA22基因盒.aadA22是四川分离菌株中首次报道,介导氨基糖苷类耐药.结果表明I型整合子普遍存在于大肠杆菌临床菌株中.尽管菌株携带的整合子-基因盒与其多重耐药谱间不存在对应关系,但不同来源菌株中检测出相同的耐药基因盒片段,说明了通过整合机制耐药基因可在不同菌株问水平传递. 相似文献
9.
广东水禽源大肠埃希菌耐药性及氨基糖苷类耐药基因研究 总被引：1，自引：0，他引：1
为了调查广东地区水禽源大肠埃希菌对氨基糖苷类药物耐药现状和耐药基因的流行情况,探索大肠埃希菌的氨基糖苷类耐药基因型与耐药表型之间的关系,本研究采用琼脂梯度稀释法测定251株广东地区水禽源大肠埃希菌对氨基糖苷类药物的耐药性和采用PCR方法检测耐药基因。药敏试验结果显示,大肠埃希菌对链霉素耐药较严重,鸭源和鹅源的耐药率分别为81.58%和75.43%,对庆大霉素和卡那霉素较敏感,耐药率分别为25%和54.86%,对阿米卡星最为敏感,其中鸭源的菌株耐药率仅为1.32%。PCR方法检测显示,aadA1和aph(3′)-1检出率较高,为84.6%和91.9%,表明携带aadA1和aph(3′)-1耐药基因的水禽源大肠埃希菌在广东地区呈流行趋势。耐药基因型与耐药表型相关性分析结果显示,耐药基因rmtB的携带与4种药物(庆大霉素、阿米卡星、卡那霉素和壮观霉素)耐药株的产生具有显著相关性,表明耐药基因rmtB对大肠埃希菌耐药株的产生起重要的作用。本试验结果可为指导广东地区水禽大肠埃希菌病的临床用药提供理论基础和研究大肠埃希菌的耐药基因提供相关的数据。 相似文献
10.
猪源大肠杆菌耐药性与I型整合子关系研究 总被引：1，自引：0，他引：1
目的为了解猪源大肠杆菌中I型整合子的流行情况,探讨I型整合子与大肠杆菌耐药表型的相关性。方法采用微量肉汤稀释法测定119株猪源大肠杆菌对8类14种抗菌药物的耐药性,并采用PCR法检测猪源大肠杆菌I型整合酶基因（int11）并扩增其可变区,对PCR产物进行酶切分析,测序分析整合子可变区携带的耐药基因盒。结果119株大肠杆菌耐药现象十分严重,对四环素、磺胺异恶唑、新诺明全部耐药,所有菌株均呈多重耐药。119株猪源大肠杆菌中有92株含I型整合子,检出率77．31％。扩增出7类大小不同的基因盒插入区片段,范围为1008bp-3149bp。7类I型整合子在119株猪源大肠杆菌中存在13种流行组合。78．15％大肠杆菌菌株的I型整合子携带2种或2种以上的基因盒,其中以携带编码氨基糖苷类药物耐药基因（aadA1、aadA2、aadA5、aadA22、aadB）最多,其次为编码磺胺类药物耐药基因（dfrA1、dfrA12、dfrA17、dfrA27）,此外还携带编码利福平、林可霉素和氯霉素的基因1nuF、cm1A6、aar-3、off.结论I型整合子普遍存在于大肠杆菌中,且呈流行上升趋势;I型整合子参与耐药及多重耐药,但单株细菌携带的耐药基因盒与其耐药表型无对应关系。 相似文献
11.
Fifty six Danish streptomycin (Sm) resistant isolates of Salmonella enterica serotype Typhimurium from pigs (n=34), calves (n=3) and humans (n=19) were characterised with respect to co-resistances (14 drugs), transferability of Sm-resistance by conjugation, genetic determinants encoding Sm-resistance and diversity with respect to localisation of genes in the genome and DNA-sequences. Forty-six strains carried resistance(s) other than Sm-resistance. Nineteen different co-resistance patterns were observed and tetracycline was the most commonly observed resistance in these patterns. In 22 of the strains, Sm-resistance was transferred by conjugation. Eleven strains contained the gene aadA only, six strains contained aadA+strA+strB, and 35 strains contained strA+strB. Partial sequences of aadA were obtained from four strains. Three strains showed identical sequences to a published aadA sequence from the transposon Tn7, and in one strain the sequence showed one synonymous substitution compared to this sequence. Partial sequences were obtained of strA and strB in seven strains. The sequence of strB was identical to the published sequence of the plasmid RSF1010 in all strains. All seven sequences of strA were identical and differed from the sequence of strA in RSF1010 by two non-synonymous substitutions. 相似文献
12.
新疆北疆地区猪源粪肠球菌的耐药性分析 总被引：1，自引：1，他引：0
为了解新疆北疆地区猪源粪肠球菌的耐药性及相关耐药基因型的分布情况,本试验采用K-B（Kirby-Baller）琼脂扩散法检测了49株猪源粪肠球菌对8种抗菌药物的敏感性,并采用PCR法对9种相关耐药基因进行检测并测序,测序结果与GenBank中的相应基因序列比对。药敏试验结果显示,分离菌对链霉素耐药率最高,其次为青霉素和红霉素,对呋喃妥因、氨苄西林高度敏感。PCR检测结果显示,β-内酰胺类耐药基因tem的检出率最高,为93.88%,其次是四环素类耐药基因tetM,为85.71%,喹诺酮类基因gyrA和parC检出率均为42.86%,氨基糖苷类耐药基因aph（3'）-Ⅲ、aac（6'）/aph2″和ant（6'）-Ⅰ的检出率分别为36.73%、16.33%和16.33%,未检出mefA和ermB基因。本试验从表型与基因型分析发现,北疆地区猪源粪肠球菌的多重耐药现象非常严重,且其耐药表型与基因型并不完全一致。 相似文献
13.
1. The aim of this study was to investigate the occurrence of aminoglycoside resistance and the prevalence of 6 important modifying enzyme genes, i.e. (strA, strB, aph(3?′)-IIa, aac(3)-IIa, aac(6?′)-Ib and ant(3?″)-Ia), in Escherichia coli strains in broilers with septicaemia in Hebei, China.2. A total of 111 clinical isolates of E. coli were collected from 46 large-scale farms. Antimicrobial susceptibility tests, using the Kirby–Bauer disc diffusion method, were performed on all 111 isolates. In addition, all were screened for the presence of modifying enzyme genes using the polymerase chain reaction (PCR).3. The results show that the rates of resistance were as follows: streptomycin: 97.3%, kanamycin: 97.0%, gentamicin: 95.5%, neomycin: 50.5%, amikacin: 46.0%, spectinomycin: 22.5%. Of the genes examined, strB (73.9%) was the most frequently identified gene in the phenotypic resistant isolates, followed in order by: ant(3?″)-Ia, aac(3)-IIa, aac(6?′)-Ib, aph(3?′)-IIa and strA.4. It is concluded that aminoglycoside resistance in E. coli from broilers with septicaemia remains a serious problem in Hebei, China. This emphasises the need to ban the non-therapeutic use of antibiotics, discourage their misuse and to be continually vigilant by providing appropriate scientific and technological support for the poultry industry. 相似文献
14.
为指导临床合理用药并为治疗患病水貂提供依据,本试验对山东省某水貂养殖场送检的7只疑似患有沙门氏菌病的病死水貂的肝脏和脾脏样品进行细菌分离鉴定及药物敏感性分析,通过分离纯化方法从样品中分离菌株,并采用革兰氏染色、生化鉴定和PCR方法对分离菌株进行鉴定。运用K-B药敏法检测菌株对临床常用药物的敏感性,并通过PCR方法检测菌株耐药基因及Ⅰ类整合子的携带情况。结果显示,本试验分离得到的7株菌均为革兰氏阴性、短小的杆菌;生化反应检测显示,分离菌株葡萄糖、麦芽糖、甘露醇、MR试验、枸橼酸盐、硫化氢试验均表现为阳性,初步鉴定分离菌株为沙门氏菌;PCR产物测序结果进一步表明7株分离菌均为沙门氏菌;药敏试验结果显示,7株沙门氏菌对头孢曲松、左氧氟沙星、氟苯尼考和多黏菌素较敏感,对氨基糖苷类药物、四环素和氨苄西林表现为耐药;耐药基因检测结果显示,7株沙门氏菌共检测出8种耐药基因blaTEM-1、blaCTX-M-1G、aadA1、aac(3′)-Ⅳ、aac(3′)-Ⅱc、aph(4′)-Ⅰa、aph(3′)-Ⅶ和oqxAB,以及基因盒为aadA1、arr-3-aacA4和blaPSE-1的Ⅰ类整合子。综上可知,本试验在送检的7只患病水貂的肝脏和脾脏样品中分离到7株沙门氏菌,分离菌株均为耐药菌株,且主要表现为多重耐药现象;耐药基因呈多样性,且存在位于质粒上的耐药基因扩大了耐药基因的传播范围,增加了细菌的耐药性,为临床用药治疗带来困难。 相似文献
15.
LIU Zheng-ming LI Jin-quan HUANG De-hao HAO Xin-wei HAO Pu-guo WU Li-qin WU Ye-ting YANG Qi-miao ZHAO Hong-xia 《中国畜牧兽医》2017,44(3):839-846
In order to determine the drug resistance phenotype and prevalence of drug resistance genes in Escherichia coli (E.coli) isolated from sheep in Inner Mongolia, the minimum inhibitory concentrations (MICs) of the isolates to antibiotics commonly used in veterinary clinical were detected by micro-dilution method in vitro. The results showed that the highest resistance rates of the isolates to amoxicillin,cephalothin,sulfamethoxazole and polymyxin were up to 100.0%,respectively.To amoxicillin-clavulanic, tetracycline and ciprofloxacin were 50% to 80%. These isolates were sensitive to cefotaxime, meropenem trihydrate, neomycin, and their resistance rates were all less than 10%. Among the 108 strains of E.coli from sheep, 94.4% of them were resistant to more than 7 antimicrobial agents,15.6% of them were resistant to 13 antimicrobial agents, only one strain was sensitive to all antimicrobial agents. Six kinds of resistance genes among the 108 E.coli isolates were detected by PCR method.The results showed that detection rates of 4 kinds of drug resistance genes including blaTEM, proP-2, sul-Ⅰ and ampG were all over 50%,the detection rate of resistance gene aph (3')-Ⅰ was up to 40%, only resistance gene aac(3)-Ⅱ detection rate was 5.5%. Thus, the sheep E.coli isolates in Inner Mongolia produced various degrees of resistance to 13 kinds of antibiotics, and their multi-drug resistances were very serious. They carried aph(3')-Ⅰ, sul-Ⅰ, ampG, blaTEM, proP-2 and aac(3)-Ⅱ resistance genes. 相似文献
16.
为确定内蒙古地区羊源大肠杆菌的耐药表型及其耐药基因的流行情况,本研究采用微量稀释法测定了内蒙古地区108株羊源大肠杆菌对13种临床常用抗菌药物的最小抑菌浓度。结果显示,分离菌株对阿莫西林、头孢噻吩、磺胺甲唑、黏菌素的耐药率最高,均达100.0%,对阿莫西林/克拉维酸、四环素、环丙沙星的耐药率在50%~80%之间,对头孢噻肟、美洛培南、新霉素的耐药率均低于10%,较为敏感。108株羊源大肠杆菌中耐7种以上药物的菌株占94.4%,其中15.6%菌株对13种抗菌药物耐药,只有1株菌对所有抗菌药物敏感。采用PCR方法对羊源大肠杆菌分离株所携带的6种相关耐药基因进行检测,结果显示,6种耐药基因中的4种耐药基因blaTEM、proP-2、sul-Ⅰ、ampG检出率超过50%,耐药基因aph（3'）-Ⅰ携带率达40%,只有耐药基因aac（3）-Ⅱ检出率仅为5.5%。由此可见,内蒙古地区羊源大肠杆菌对13种抗菌药物产生了不同程度的耐药性,且存在严重的多重耐药情况,羊源大肠杆菌分离株携带aph（3'）-Ⅰ、sul-Ⅰ、ampG、blaTEM、proP-2、aac（3）-Ⅱ耐药基因。 相似文献
17.
在胶东地区119株多重耐药大肠杆菌中,共92株菌有I型整合子整合酶基因,检出率达77．31％。92株I型整合子携带大肠杆菌共扩增出7类不同大小的基因盒插入区片段,大小分别为1008bp、1318bp、1586bp、1663bp、1913bp、1945bp、3149bp,其中以大小为1008bp的插入区片段的检出率最高,为31．67％。而检出率最低的为长度为1318bp的基因盒插入区。将基因盒插入区扩增片段的测序结果与Genebank中的相关序列进行比对,得出I型整合子携带的耐药基因盒种类分别为aadA1、aadA2、aadA5、aadA22、aadB、dfrA1、dfrA12、dfrA17、dfrA27、1nuF、cmLA6、aar-3、orff分别编码对相应药物的耐药性。 相似文献
18.
Characterization of antimicrobial resistance of Salmonella Newport isolated from animals, the environment, and animal food products in Canada 
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下载免费PDF全文 Cornelius Poppe Laura Martin Anne Muckle Marie Archambault Scott McEwen Emily Weir 《Canadian journal of veterinary research》2006,70(2):105-114
Multi-drug-resistant (MDR) Salmonella enterica serovar Newport strains are increasingly isolated from animals and food products of animal origin and have caused septicemic illness in animals and humans. The purpose of this study was to determine the occurrence and the epidemiologic, phenotypic, and genotypic characteristics of S. Newport of animal origin that may infect humans, either via the food chain or directly. During the 1993-2002 period, the Office International des Epizooties Reference Laboratory for Salmonellosis in Guelph, Ontario, received 36 841 Salmonella strains for serotyping that had been isolated from animals, environmental sources, and food of animal origin in Canada. Of these, 119 (0.3%) were S. Newport. Before 2000, none of 49 S. Newport strains was resistant to more than 3 antimicrobials. In contrast, between January 2000 and December 2002, 35 of 70 isolates, primarily of bovine origin, were resistant to at least 11 antimicrobials, including the extended-spectrum cephalosporins. The blaCMY-2', flo(st'), strA, strB, sulII, and tetA resistance genes were located on plasmids of 80 to 90 MDa that were self-transmissible in 25% of the strains. Conserved segments of the integron 1 gene were found on the large MDR-encoding plasmids in 3 of 35 strains additionally resistant to gentamicin and spectinomycin or to spectinomycin, sulfamethoxazole-trimethoprim, and trimethoprim. Resistance to kanamycin and neomycin was encoded by the aphA-1 gene, located on small plasmids (2.3 to 6 MDa). The increase in bovine-associated MDR S. Newport infections is cause for concern since it indicates an increased risk of human acquisition of the infection via the food chain. 相似文献
19.
11株新城疫病毒广西分离株NP基因的克隆和序列分析 总被引：4，自引：0，他引：4
根据基因库中新城疫病毒(NDV)的NP基因序列设计了1对特异性引物,应用RT-PCR技术对广西在2000～2003年暴发新城疫的鸡群中分离的11株NDV毒株NP基因进行RT-PCR扩增和序列测定,拼接出11个NDV广西分离株的NP基因的全序列,10个NDV广西分离株的NP基因阅读框的核苷酸序列全长均为1470 bp,编码489个氨基酸,它们的NP基因核苷酸全序列及推导的氨基酸全序列与10个已发表的NDV参考株的NP基因全序列比较分析结果表明:核苷酸序列同源性为84.8%～98.2%,氨基酸同源性为89.8%～99.4%. 相似文献
20.
QU Su-jie ZOU Lian-bin HU Jie SU Yan-qiong MO Sheng-lan SHI Kai-chuang YIN Yan-wen LI Jun ZHANG Bu-xian 《中国畜牧兽医》2016,43(1):45-49
To investigate genetic variation of Marek's disease virus(MDV) in Guangxi province, three isolates of MDV were isolated from infected chicken.One pair of primers for amplifying Meq gene of MDV was designed according to nucleotide sequence in GenBank, Meq gene of the isolates were amplified by PCR, and then cloned, sequenced and compared with reference MDV strains published in GenBank.The results showed that Meq gene from all of the MDV isolates consisted of 1020 bp, coding for 339 amino acids.Compared with reference strains published in GenBank, the sequences of Meq gene in different isolates were relatively conserved and the homologies of nucleotide and amino acid sequence of the isolates were 83.8% to 99.9% and 88.4% to 99.6%, respectively.The proline-rich repeats of Meq gene of the MDV isolates had site mutations, and it was related to MDV's virulence.The isolate were nearly related to YL and GXY2, and far away from RB1B, GA, Md5, 648A and the immune strain phylogenetically.The study would provide research materials for the prevalence, genetic variation, protection and control of MDV in China. 相似文献