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《中国家禽》2021,(12)
为研究肉鸡生产链中弯曲杆菌的流行规律,从广东省广州市、佛山市的家禽养殖场、屠宰场和市场中采集了1 414份样本,通过分离细菌、检测耐药性及耐药基因等方法分析该病的流行规律。结果显示:共分离出201株弯曲杆菌,阳性率为14.21%,且养殖场(25.1%)到屠宰场(11.9%)到市场(7.1%)的弯曲杆菌污染率呈现递减趋势;弯曲杆菌分离株对喹诺酮类和磺胺类药物具有高耐药率且喹诺酮类药物耐药菌株的gyrA基因QRDR区域发生了C257T的突变,突变率为100%;大环内酯类药物耐药菌株的23 S rRNA基因均发生了A2075G点突变。此外,大环内酯类耐药株的甲基化酶耐药基因ermB的携带率为52.38%,四环素类药物耐药株的tet(O)基因的携带率为97.37%。研究表明广东省部分地区禽源弯曲杆菌对喹诺酮类耐药率高且多重耐药情况普遍,提示加强禽源弯曲杆菌耐药基因的监测。 相似文献
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《中国预防兽医学报》2020,(8)
为了解江苏某肉鸡屠宰场弯曲菌分离株耐药性及氨基糖苷类耐药基因簇aadE-sat4-aphA-3的分布特点,本研究采用药敏纸片法对肉鸡屠宰场117株弯曲菌分离株进行9大类26种抗生素的耐药性检测。结果显示,117株菌对链霉素和卡那霉素耐药的菌株占93.2%(109/117),对头孢氨苄耐药菌株占96.6%(113/117),对氟喹诺酮类药物耐药菌株占比均大于89.7%(105/117),对碳青霉烯类及氯霉素类药物较为敏感,且94%(110/117)的菌株表现出多重耐药性。采用PCR方法检测氨基糖苷类耐药基因簇aadE-sat4-aphA-3的分布情况。结果显示,有90株弯曲菌(空肠弯曲菌17、结肠弯曲菌73)检出了aadE-sat4-aphA-3耐药基因簇。进一步采用琼脂稀释法测定了其中20株aadEsat4-aphA-3阳性菌对氨基糖苷类5种药物的最小抑菌浓度(MIC)。结果显示,20株aadE-sat4-aphA-3基因簇阳性弯曲菌中共有12株对庆大霉素耐药,MIC值最高为256μg/mL,共有11株对受试的5种氨基糖苷类药物均耐药,且大部分菌株对阿米卡星、妥布霉素的MIC值≥256μg/mL。表明aadE-sat4-aphA-3基因簇阳性弯曲菌对氨基糖苷类药物有较强的耐药性。综上所述,江苏某肉鸡屠宰场弯曲菌对氟喹诺酮类及氨基糖苷类部分药物耐药性较高且多重耐药现象严重,空肠弯曲菌与结肠弯曲菌中均有aadE-sat4-aphA-3耐药基因簇分布,且部分该耐药基因簇阳性菌株对氨基糖苷类药物耐药性较强。本研究为畜禽养殖临床用药指导提供了参考依据,并为弯曲菌氨基糖苷类药物耐药机理的进一步研究奠定基础。 相似文献
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为了解禽肉结肠弯曲杆菌的耐药表型和分子型,采用琼脂平板稀释法和多位点序列分型(Multilocus Se-quence Typing,MLST)技术分别对54株禽肉结肠弯曲杆菌进行耐药性及分子分型研究。耐药性试验结果得到单重耐药菌株有41株(75.9%),分别是对环丙沙星耐药有9株(16.7%)、对强力霉素耐药有23株(42.6%)和对红霉素耐药有9株(16.7%);多重耐药菌株有10株(18.5%),其中4株(7.4%)对环丙沙星和强力霉素耐药,1株(1.9%)对环丙沙星和红霉素耐药,4株(7.4%)对红霉素和强力霉素耐药,1株(1.9%)对环丙沙星、红霉素和强力霉素耐药;所有菌株对硫酸庆大霉素敏感。MLST得到了38个(含1个新的)等位基因(allele);26个(含8个新的)序列型(Sequence type,ST);2个已知序列型克隆系(ST clonal complexes),ST-828克隆系(45株,83.3%)和ST-1150克隆系(3株,5.6%),以及5个(6株,11.1%)没有序列型克隆系。耐药性与序列型和序列克隆系相关性比较,相关性不大。结果提示,禽肉结肠弯曲杆菌出现了对环丙沙星、红霉素和强力霉素的单重及多重耐药菌株;禽肉中结肠弯曲杆菌主要流行ST-828克隆系;耐药性与序列型及序列克隆系相关性差,揭示耐药菌株来源广泛。 相似文献
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动物源性空肠弯曲杆菌耐药性地域差异性分析 总被引：1，自引：0，他引：1
从上海家禽批发市场采集鸡盲肠内容物样品,分离到47株空肠弯曲杆菌,从上海屠宰场采集猪盲肠内容物样品,分离到99株空肠弯曲杆菌,分别测定分析了这些空肠弯曲杆菌耐药性;
通过对不同产地鸡源空肠弯曲杆菌耐药性状况比较结果显示,江苏南通、江苏海门和浙江金华分离到的鸡源空肠弯曲杆菌对9种抗生素(见表1)都有不同程度的耐药性,对万古霉素、红霉素和氨苄青霉素的耐药性达到100%。江苏海门、上海崇明和浙江温岭、金华等地的菌株分别对克林霉素和氨苄青霉素显示了高耐药性,分别达到90%、100%;通过对不同产地猪源空肠弯曲杆菌耐药性状况比较结果显示,山东莘县分离到的猪源空肠弯曲杆菌对9种抗生素都有不同程度的耐药性,对万古霉素、红霉素、克林霉素和氨苄青霉素的耐药性达到80%以上。河南孟津和安徽淮北分离到的猪源空肠弯曲杆菌对除头孢拉定之外的8种抗生素都有不同程度的耐药性,对氨苄青霉素的耐药性达到100%。结果显示动物源性空肠弯曲杆菌耐药性存在明显的地域差异性。 相似文献
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为了解新疆维吾尔自治区阿克苏地区新和县规模化养殖场及散养户中不同阶段的牛细菌性腹泻病原菌的分布情况及耐药性情况。对2020—2021年采集新疆维吾尔自治区阿克苏地区新和县规模化养殖场及散养户中不同阶段的患腹泻牛粪便、肛拭子及内脏病料358份,采用细菌分离鉴定、形态学观察、生化鉴定等方法对大肠杆菌、沙门菌、奇异变形杆菌、空肠弯曲杆菌等细菌性病原菌进行分离鉴定,采用K-B药敏纸片法检测临床分离菌株对临床中常用的药物耐药情况。结果显示：从358份病料样品中分离到大肠杆菌62株、沙门菌52株、空肠弯曲杆菌29株、奇异变形杆菌28株,检出率分别为17.3%、14.5%、8.1%、7.8%;分离的菌株对临床中常用的药物产生不同的耐药性,其中大肠杆菌、沙门菌、空肠弯曲杆菌及奇异变形杆菌均对头孢噻呋、头孢喹肟、氟苯尼考、恩诺沙星、环丙沙星、林可霉素、硫酸黏菌素等药物敏感,对其他药物耐药。为该牛细菌性腹泻病防治及合理指导临床用药提供参考。 相似文献
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DNA旋转酶基因gyrA中喹诺酮耐药决定区碱基变换在大肠杆菌对喹诺酮的耐药性方面起着十分重要的作用.采用PCR-SSCP(PCR-单链构象多态性)技术可对大肠杆菌gyrA基因QRDR的突变进行有效检测.本文以142株猪源致病性大肠杆菌氟喹诺酮药物敏感菌株为样本,测定了细菌对喹诺酮药的MIC值,结果表明142株猪源大肠杆菌对环丙沙星、恩诺沙星、诺氟沙星、氧氟沙星的耐药率分别为78.8%,56.3%,65.5%,76.8%.猪源大肠杆菌对氟喹诺酮药物的耐药率高,且耐药菌株MIC值较大.菌株WJPE2-1(对环丙沙星的NIC为0.5μg/mL)的诱导耐药试验,结果表明,在通过药物浓度梯度连续诱导过程中获得了MIC为2,8,64,128μg/mL的四株诱导菌株,诱导菌株4对ENR、NOR、OFL、CIP的MIC值分别增加到诱导前的32,128,128,256倍,且4株诱导菌株对CIP、ENR、NOR、OFL的MIC值均呈现递增.根据GenBank注册的大肠杆菌gyrA序列设计引物,横跨gyrA的第40和118密码子位置,包含完整的QRDR,从27株不同MIC值的大肠杆菌株、ATCC25922、4株诱导耐药菌株均获得约300bp的PCR产物.采用291的交联度、12%的聚烯酰胺浓度,1×TBE,凝胶中添加5%的甘油的条件,对诱导菌株、药物敏感菌株及不同耐药水平的分离菌株进行SSCP分析,结果表明,诱导菌株的谱型与敏感对照菌不同,低MIC值菌株SSCP谱型与敏感对照与敏感对照一致性高;耐药菌株的谱型多数与敏感对照不同.四株诱导大肠杆菌PCR产物的SSCP谱型均与对照不一致,检出率为100%;27株不同耐药性的猪源大肠杆菌中,7株敏感大肠杆菌共有6株的SSCP谱型与标准敏感菌株对照一致,符合率为85.7%;20株耐药大肠杆菌其谱型与标准敏感对照一致的菌株为2株,检出率为90.0%.序列比较结果表明,敏感菌株WJPE2-1的PCR产物与敏感对照有2个碱基(第91,111位氨基酸残基位置)的差异,序列同源率为99.16%(236/238).诱导菌株1与2表现在第83位氨基酸编码序列由tcg突变为ttg,菌株3、4与菌株1、2的差异表现在第87位氨基酸编码序列由gac突变为tac.进一步分析发现,菌株WJPE2-1在第91位及111位的突变均为同义突变,即密码子的变换没有引起氨基酸残基的改变.在诱导菌株中,1与2的gyrase的第83位氨基酸残基由Ser→Leu,菌株3、4的gyrase还在第87位氨基酸残基由Asp→Tyr.表明由于QRDR内碱基的改变,引起DNA旋转酶氨基酸的变化,导致大肠杆菌产生氟喹诺酮药物的耐药性. 相似文献
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【目的】掌握浙江省德清县驯养朱鹮大肠杆菌的耐药性、耐药基因与分子特征,为治疗朱鹮大肠杆菌感染提供基础数据。【方法】采集该地驯养朱鹮新鲜粪便样本,采用分离培养、形态观察、生化鉴定及16S rDNA序列分析鉴定大肠杆菌;进而采用肉汤稀释法检测环丙沙星、庆大霉素、丁胺卡那等7种抗菌药对源自不同朱鹮的大肠杆菌分离株菌株的最小抑菌浓度(minimal inhibitory concentration, MIC);选择代表性菌株,通过PCR和测序鉴定其携带qnrS1、gyrA、gyrB等9种喹诺酮类耐药基因的情况,并分析其蛋白关键氨基酸位点突变与耐药性的关系,采用接合转移分析耐药质粒水平转移情况及其与耐药性的关系,应用卡方检验(Chi-square test)和费歇尔精确检验(Fisher exact test)分析分离株耐药表型与朱鹮年龄、耐药基因的相关性。【结果】本研究共采集了98只朱鹮的粪便,经分离鉴定均获得了大肠杆菌;源自不同朱鹮的98株大肠杆菌对喹诺酮类环丙沙星呈现高度耐药(耐药率为65.3%,64/98),对其余6种药物高度敏感(敏感率均>90%),朱鹮年龄与环丙沙星耐药性极显著... 相似文献
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Chuma T Maeda T Niwa H Okamoto K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(2):155-160
A dramatic rise in the number of resistant Campylobacter to quinolones has been documented in human patients and domestic animals. In this study, the mechanism of acquisition of quinolone resistance was studied by detecting point mutations in the gyrA gene of Campylobacter strains obtained from broilers and strains with in vitro-induced resistance. The minimal inhibitory concentrations (MICs) of norfloxacin (NFLX) and ofloxacin (OFLX) for the strains that had no point mutation were slightly increased from the source strain (Campylobacter jejuni ATCC 33560). The MICs of nalidixic acid (NA), NFLX, and OFLX for the strains that had the point mutation at Thr-86 were 100 or 200 microg/ml, 50 microg/ml, and 25 microg/ml, respectively. The MIC of NA for the strain that had a point mutation at Asp-90 higher than those for the strains that had the point mutation at Thr-86, but the MICs of NFLX and OFLX were relatively lower than those for the strains that had point mutation at Thr-86. These findings suggest that the degree of antimicrobial resistance against NA, NFLX, and OFLX in the in vitro-induced C. jejuni strains was associated with the location of the point mutation in gyrA. On the other hand, a point mutation in all seven resistant strains isolated from broilers was located only at Thr-86, while the MICs of the three quinolones varied in each wild strain. This suggests that another mechanism might also be involved in the acquisition of quinolone resistance in C. jejuni wild strains. 相似文献
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探讨不同禽源大肠埃希菌中喹诺酮类药物的耐药情况及耐药基因gyrA的分布和突变特征。采用K-B药敏纸片法、gyrA基因的PCR扩增,对9株大肠埃希菌进行喹诺酮类药物试验,并将gyrA基因的PCR产物测序,对测序结果采用DNA MAN、DNA Star、MEGA6等软件分析。药敏试验结果表明,C1、C2、C3菌株对左氧沙星、氧氟沙星、环丙沙星、诺氟沙星敏感,D1、D2、D3、B1、B2和B3菌株对左氧沙星、氧氟沙星、环丙沙星、诺氟沙星均表现为耐药和中介;gyrA基因的测序结果表明,除B1菌株有1处核苷酸突变位点和B2菌株有14处核苷酸突变位点;B2菌株gyrA基因的氨基酸突变发生在87位Ile→Val替代、101位Leu→Met替代、102位Ala→Ser替代、129位Lys→Gln替代。9株禽源大肠埃希菌的同源性和进化树分析表明,不同禽源耐氟喹诺酮类药物的大肠埃希菌菌株中B2菌株gyrA基因与其他9株菌株相比,同源性在90%左右,进化树不在一个分支上,研究中的B2菌株将为大肠埃希菌的氟喹诺酮类耐药机制的研究提供候选菌株。 相似文献
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Antimicrobial resistance of thermophilic Campylobacter spp. isolated from cattle in Poland 总被引：1，自引：0，他引：1
Campylobacter species are among the most frequently identified bacterial causes of human gastroenteritis. Because Campylobacter spp. harbored by cattle can be transmitted to humans, in this study we investigated antimicrobial resistance of thermophilic Campylobacter isolated from cows. Our study included 150 strains of Campylobacter (143 strains of C. jejuni and 7 strains of C. coli) isolated from cows in South-Western Poland. The minimal inhibitory concentration (MIC) to ciprofloxacin, erythromycin, gentamicin and tetracycline were determined using the agar dilution methodology. All strains of C. coli were susceptible to all four drugs studied. The most frequently detected resistance of C. jejuni was to ciprofloxacin (26 strains 18.2%). Resistance to tetracycline was observed in 5 strains (3.5%). All strains of C. jejuni were susceptible to erythromycin and gentamicin. 相似文献
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The genetic diversity of 115 Campylobacter coli strains, isolated from pigs of 59 geographical distant farms in Switzerland, were characterized on the basis of their DNA fingerprints and resistance to macrolides and fluoroquinolones. Sequence analysis showed that the macrolide-resistant isolates had a point mutation in the 23S ribosomal RNA (rRNA) genes (A2075G) and that the fluoroquinolone-resistant isolates had a point mutation in the gyrase gene gyrA (C257T). One fluoroquinolone-resistant strain had an additional transition mutation in the gyrB gene (A1471C). The flaA restriction fragment length polymorphism (RFLP) genotyping revealed that 57% of the isolates were genetically different. Point mutations in the 23S rRNA and gyrA genes could be found in both genetically distant and genetically related isolates. Additionally, isolates with and without point mutations were found within individual farms and on different farms. This study showed that the ciprofloxacin and erythromycin-resistant C. coli population present on the pig farms is not issued from a common ancestral clone, but individual Campylobacter strains have most likely mutated independently to acquire resistances under the selective pressure of an antibiotic. 相似文献
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Thermotolerant Campylobacter spp. are frequent causes of diarrhoea in humans worldwide mostly originating from poultry. It has been suggested that extensive veterinary use of antibiotics is largely responsible for resistance in human isolates. During a 4-month period from January to April 2004, 192 Campylobacter spp. were isolated from fecal samples of 485 healthy food animals. The in vitro susceptibility to 12 antibiotics was determined by the agar disk diffusion method. Among the 192 Campylobacter spp. isolated, 135 (70.3%) were identified to be C. jejuni, 51 (26.6%) were C. coli and 6 (3.1%) were C. lari. C. jejuni was the most prevalent species in chickens (80.8%) versus 16.2% C. coli and 3.0% C. lari. All isolates found in pigs were C. coli. All strains were sensitive to chloramphenicol and ciprofloxacin and all were resistant to cephalothin. More than 90% of the strains were sensitive to clindamycin, erythromycin, gentamicin, nalidixic acid, norfloxacin, streptomycin and tetracycline. Resistance was found against ampicillin in 20% and trimethoprim-sulphamethoxazole in 37.5%. Resistance was not statistically different among C. jejuni, C. coli and C. lari (p>0.05). Multidrug resistance to two or more drugs was detected in 14.5% of strains. In conclusion, the study showed that antimicrobial resistance is found only at relatively low frequencies for most antimicrobial agents tested except for ampicillin and trimethoprim-sulphamethoxazole. The low percentages of resistance to most antimicrobial agents tested in this study may be the result of low/no usage of these agents as a growth promoters or treatment in the Ethiopian animal farm setting. The detection of multidrug resistant isolates may pose a threat to humans and further limits therapeutic options. 相似文献
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本研究旨在探讨不同血清型沙门氏菌在环丙沙星抗生素压力下突变频率及在耐药发展过程中靶位基因突变、外排泵及调控基因表达的差异。选取临床分离的印第安纳型、肠炎型和鼠伤寒型沙门氏菌的敏感菌株,在环丙沙星压力下诱导耐药突变,分别获得一系列不同程度的耐药突变株。分别检测不同血清型沙门氏菌突变株的突变频率、靶位基因喹诺酮耐药决定区(QRDRs)和外排泵调控基因ramR-ramA突变及外排泵相关基因的表达水平;同时检测了母株在羰基氰化物间氯苯腙(CCCP)存在情况下环丙沙星药物的蓄积浓度,以确定母株是否存在外排泵的作用。结果表明,在环丙沙星压力下,印第安纳型沙门氏菌较肠炎型和鼠伤寒型有更高的突变频率,易获得耐药株;印第安纳血清型菌株耐药性的获得主要是由于靶位基因gyrA发生单突变,协同外排泵外排作用增强而获得高水平耐药;肠炎型沙门氏菌耐药性获得主要是由于靶位基因gyrA发生83和87位双位点突变,并随着gyrB和parC基因的多位点同时突变而获得高水平耐药,耐药性的发展过程中没有外排泵作用参与;而鼠伤寒沙门氏菌在抗生素压力下不易发展成耐药菌,耐药性发生主要是由于靶位基因gyrB发生突变,而伴随parC基因突变及微弱的外排泵作用导致耐药水平增加。 相似文献
17.
取临床分离的、对5种氟喹诺酮类药物（环丙沙星、氧氟沙星、恩诺沙星、单诺沙星和沙拉沙星）均耐药的9株鸡源性沙门氏菌耐药株,提取其染色体DNA。设计引物gyrAF和gyrAR、gyrBF和gyrBR,分别扩增菌株DNA旋转酶gyrA基因和gyrB基因的氟喹诺酮类耐药决定区（QRDR）,对PCR扩增产物进行测序及序列分析。与质控菌株相比,9株临床分离耐药株中只有菌株38和60的gyrA基因发生单碱基突变,菌株38的gyrA基因第371位碱基发生C→T突变,菌株60的gyrA基因第350位碱基发生A→C突变,两处突变均位于QRDR内,其余菌株的核苷酸未发生任何突变。菌株38的碱基突变导致gyrA基因第99位氨基酸发生R→C取代,即Arg→Cys;菌株60的碱基突变导致gyrA基因第92位氨基酸发生M→L取代,即Met→Leu。9株临床分离鸡源性沙门氏菌氟喹诺酮类耐药株gyrB基因QRDR的核苷酸序列与质控菌株完全相同;只有菌株42的gyrB基因第1592位碱基发生C→A突变,但其位于gyrB基因QRDR之外,且菌株42的gyrB基因的碱基突变并没有导致相应氨基酸的改变。上述结果提示,DNA旋转酶gyrA基因和gyrB基因QRDR突变可能并非沙门氏菌耐药性产生的主要原因。 相似文献
18.
Minihan D Whyte P O'mahony M Cowley D O'halloran F Corcoran D Fanning S Collins JD 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2006,53(4):181-187
Anti-microbial resistance is an emerging public health issue. Farmed animals may act as reservoirs and potential sources of anti-microbial resistant Campylobacters. The aim of this study was to investigate the anti-microbial resistance profile of cattle and environmental Campylobacter isolates from normal untreated feedlot cattle, the role of the gyrA Thr-86-Ile mutation in ciprofloxacin-resistant Campylobacter jejuni isolates and the involvement of the tripartite CmeABC efflux system for multi-resistant C. jejuni isolates. The phenotypic anti-microbial resistance testing was carried out on 500 Campylobacter isolates (445 cattle isolates and 55 environmental isolates). In general, there was a higher level of anti-microbial resistance for the environmental isolates compared with the animal isolates, 45% of the animal isolates were resistant to one or more of the seven anti-microbials compared with 84% of the environmental isolates. The combined cattle and environmental Campylobacters had 34 (6.8%) isolates resistant to three or more of the seven anti-microbials tested on all isolates and 11 (2.2%) isolates were resistant to the seven anti-microbials. There was a substantial level of ciprofloxacin-resistant Campylobacters in both animal (8.5%) and environmental (21.8%) isolates. The gyrA Thr-86-Ile mutation was only present in five of 22 ciprofloxacin-resistant C. jejuni isolates investigated. No multi-drug-resistant associated mutation was detected in the CmeB or the CmeR regions investigated. In conclusion, our study observed a substantial level of Campylobacter anti-microbial resistance, highlighting the need for an active anti-microbial surveillance program for food animals in Ireland and the importance of the chosen sampling point can have on the findings of such a program. 相似文献
19.
Lukkana M Wongtavatchai J Chuanchuen R 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(4):435-440
The aim of this study was to determine antimicrobial resistance of Aeromonas hydrophila isolated from farmed Nile Tilapia. A total of 50 A. hydrophila isolates from clinical cases were screened for the presence of class 1, 2 and 3 integrons and all the strains resistant to enrofloxacin and/or ciprofloxacin (n=19) examined for mutation in the quinolone resistance-determining regions (QRDRs) of gyrA and parC. The intI1 gene was detected in 23 A. hydrophila strains (46%) but no intl2 and intl3 were detected. Among these, 14 isolates (60.8%) carried gene cassettes inserted in variable regions i.e., partial aadA2, aadA2, dfrA1-orfC and dfrA12-aadA2, of which the most common gene cassette array was dfrA12-aadA2 (26.09%). Conjugal transfer of class 1 integrons with resistance gene array was detected. All the A. hydrophila strains resistant to enrofloxacin and/or ciprofloxacin possessed mutations in the QRDRs of gyrA and parC. Only a Ser-83-Ile substitution was identified in GyrA and only a Ser-80-Ile amino change was found in ParC. The data confirms that A. hydrophila from farm-raised Nile Telapia serve as a reservoir for antimicrobial resistance determinants. 相似文献