广东省广州市猪禽屠宰场环境沙门氏菌血清分型与耐药性分析

为了解广东省广州市屠宰环节环境中沙门氏菌血清型分布及其耐药性,对广州市大型生猪、家禽屠宰企业环境进行监控,对比分析猪禽屠宰场污染的沙门氏菌主要血清型和耐药谱.采集屠宰场的空气、土壤、污泥样品,以及运输车辆、待宰圈/舍、屠宰车间等环境拭子样品,利用沙门氏菌特异性引物进行PCR扩增和测序鉴定;通过玻片凝集法,对PCR鉴定阳...     

广东省零售市场鸡肉中肯塔基沙门菌的流行情况及耐药性分析

本研究旨在了解广东省零售市场鸡肉中肯塔基沙门菌的流行情况、耐药水平与耐药基因携带情况。对2016年从广东省五个地级市采集的鸡肉样品进行沙门菌分离鉴定、血清型鉴定、药敏试验、耐药基因的检测和分子分型。结果显示,245份鸡肉样品中沙门菌阳性率为62.04%（152/245）,共鉴定出19种血清型,其中主要血清型有阿贡纳（Salmonella Agona,29/152,19.08%）、科瓦利斯（S.Corvallis,25/152,16.45%）以及肯塔基（S.Kentucky,20/152,13.16%）。肯塔基沙门菌药敏试验结果显示对磺胺异噁唑（100%）、萘啶酸（90%）、四环素（75%）、氨苄西林（65%）、头孢他啶（55%）、环丙沙星（55%）的耐药率较高,有85%（17/20）的菌株对3种及3种以上的抗菌药物耐药。对喹诺酮耐药基因的检测结果显示,95%（19/20）的菌株具有gyrA突变（Ser83Phe、Asp87Asn、Asp87Gly）,其中有57.89%（11/19）的菌株发生gyrA双突变（Ser83Phe与Asp87Asr、Ser83Phe与Asp87Gly）,5.26%（1/19）发生gyrA三突变（Ser83Phe、Asp87Asn、Asp87Gly）;100%（20/20）的菌株具有parC突变（Tyr62Ser、Ser85Ile）。45%（9/20）分离株携带质粒介导的喹诺酮抗性（PMQR）基因（aac（6'）-Ib-cr、qnrB、qnrS、oqxAB）,最常见的是aac（6'）-Ib-cr耐药基因。β-内酰胺类耐药基因bla_TEM-1、bla_OXA-1和bla_CTX-M-55的检出率分别为25%、10%和5%。PFGE图谱的聚类分析结果显示,肯塔基沙门菌之间具有不同的亲缘关系与遗传多样性,部分菌株具有高度同源性。肯塔基沙门菌在广东省零售市场鸡肉中是主要的流行血清型之一。其对传统药物磺胺异噁唑、萘啶酸、四环素和氨苄西林耐药较严重,对环丙沙星以及头孢他啶耐药尤其严重,具有多种多重耐药表型。肯塔基沙门菌其喹诺酮耐药决定区突变率高。分子分型揭示了菌株间跨地区传播的可能,为肯塔基沙门菌溯源提供一定的依据。     

Mitogenic Equine Isolates of Streptococcus zooepidemicus From North America Host Superantigen Genes Similar to Those Hosted in Europe

Streptococcus equi subsp. zooepidemicus (Sz) is an important opportunist pathogen of the equine respiratory and reproductive tracts. It is highly variable with respect to sequence type and virulence factors including SzP and SzM. Recent studies in the UK have shown that many Sz strains host genes for mitogenic superantigens including szeF, szeN, szeP, seeI, seeL, and seeM. The aims of the present study were to estimate the prevalence of mitogenicity in equine Sz in North America and establish whether mitogenicity is more likely to be associated with isolates from a specific site of infection. Twenty-six percent (23/90) of strains randomly selected from over 600 Sz isolated in the United States from 1969 to 1994 were mitogenic for equine peripheral blood mononuclear cells. All but five of these mitogenic Sz encoded one or more of the superantigen genes szeF, szeN, szeP, seeI, seeL, and seeM. Homologues of seeH in S. equi were not detected in any Sz strain. Polymerase chain reaction analysis revealed the presence of seeI, szeF, szeN, or szeP in 91% (10/11) of isolates from lymph node abscesses confirming earlier reports of a significant association of superantigens with lymph node abscessation in the UK. In contrast, only 24% (4/17) of Sz isolates from the reproductive tract were mitogenic and/or hosted seeL, seeM, szeF, szeP, or szeN.     

鱼塘生态体系中大肠埃希菌和沙门菌的耐药性研究

为了解鱼塘生态体系大肠埃希菌和沙门菌的耐药情况,从广东省佛山某鱼塘随机采集草鱼及生活圈的水土样品中(包括鱼肠内容物、鱼塘底泥、鱼塘水)分离出47株大肠埃希菌和23株沙门菌.采用纸片扩散法(Kirby-bauer,KB)对分离菌株进行了15种抗生素的敏感性试验,结果显示100%的菌株均耐1种及1种以上的抗生素多表现出对氨...     

鸡白痢沙门菌的分离鉴定与耐药性分析

本研究采集某鸡场疑似感染鸡白痢的病死鸡组织,进行了沙门菌的分离、鉴定,以及对10种常见抗生素的药物敏感性试验.结果显示:分离株均为鸡白痢沙门菌,对阿米卡星(0％)、庆大霉素(0％)、头孢噻肟(3.70％)的耐药率较低,对链霉素(88.89％)、四环素(62.96％)、阿莫西林(51.85％)的耐药率较高;分离株至少可对...     

广州市农贸市场猪肉源伦敦沙门菌的流行情况及耐药性分析

本研究旨在探究广州市2016年5-10月农贸市场猪肉源伦敦沙门菌的流行和耐药情况.从广州市农贸市场采集样品198份,分离得到28株猪肉源伦敦沙门菌,用K-B法测定其对18种抗菌药物的耐药性,用PCR方法鉴定其所携带的耐药基因.结果表明,市场猪肉样品中沙门菌的阳性率为74.2％(147/198),伦敦沙门菌的分离率为19...     

Prevalence and Antimicrobial Resistance of Salmonella enterica Serovar Indiana in China (1984–2016)

Salmonella enterica serovar Indiana, first described in 1955, is generally regarded as having a low frequency worldwide with outbreaks of gastroenteritis and abortions described in North America and Europe. In China, S. Indiana was first reported in 1984 and in the subsequent 71 surveys in 35 cities/municipalities from 18 provinces, 70% of which were after 2012, S. Indiana has been shown to have become widely prevalent in people, animals, food and the environment around abattoirs and meat processing facilities. The organism is now one of the most common serovars found in livestock and raw meat in China with S. Indiana isolates having high levels of drug resistance, especially against tetracyclines, quinolones, folate pathway inhibitors, phenicols, penicillins, monobactams and nitrofurans. Further, S. Indiana isolates that are concurrently resistant to ciprofloxacin and ceftriaxone/cefotaxime have emerged. Studies have suggested the high levels of multidrug resistance of S. Indiana might be associated with the presence of class 1 integrons and plasmids. Unfortunately, information on the high prevalence of S. Indiana and its extensive drug resistance in China has largely escaped international recognition as it largely appears in local reports written in Chinese. To address this situation, we reviewed all the available local Chinese and international publications on the organism in China and report our findings in this review.     

Epidemiology of Subclinical Salmonellosis in Wild Birds from an Area of High Prevalence of Pig Salmonellosis: Phenotypic and Genetic Profiles of Salmonella Isolates

The epidemiology of subclinical salmonellosis in wild birds in a region of high Salmonella prevalence in pigs was studied. Three hundred and seventy‐nine faecal samples from 921 birds trapped in 31 locations nearby pig premises, and 431 samples from 581 birds of 10 natural settings far from pig farms were analysed for the presence of Salmonella spp. Positive samples were serotyped and analysed for antimicrobial resistance (AR). Phage typing and pulsed‐field gel electrophoresis (PFGE) on Salmonella Typhimurium isolates were also carried out. The overall proportion of Salmonella‐positive samples was 1.85% (95% CI = 0.93, 2.77). Salmonella isolation was positively associated with samples collected from birds in the proximity of a pig operation (OR = 16.5; 95% CI = 5.17, 52.65), and from non‐migratory (or short‐distance migration) birds (OR = 7.6; 95% CI = 1.20, 48.04) and negatively related to mostly granivorous birds (OR = 0.4; 95% CI = 0.15, 1.13). Salmonella Typhimurium was the most prevalent serotype and four different XbaI PFGE patterns were observed that matched the four phage types identified (U310, U311, DT164 and DT56). Only 20% of the strains showed multi‐AR. In three farms, a high degree of homogeneity among isolates from different birds was observed. These findings suggested that pig farms may act as amplifiers of this infection among wild birds, and the degree of bird density may have much to do on this transmission. Some of the Salmonella serotypes isolated from bird faeces were of potential zoonotic transmission and associated with AR. Monitoring salmonellosis in wild bird is advised.     

Characterization of Salmonella Dublin and Salmonella Typhimurium (Copenhagen) Isolates from Cattle

Brackelsberg, C.A., Nolan, L.K. and Brown, J., 1997. Characterization of Salmonella dublin and Salmonella typhimurium (Copenhagen) isolates from cattle. Veterinary Research Communications, 21 (6), 409-420Eight Salmonella typhimurium (Copenhagen) and eight Salmonella dublin isolates from cattle were compared by their antibiotic resistance patterns, by their production of colicin, aerobactin, haemolysin and capsule, by their possession of transmissible R plasmids and the spvC gene, and by their ability to invade and replicate within cultured epithelial cells. The two groups differed in their antibiotic resistance profiles, with more of the host-adapted S. dublin isolates resistant to tetracycline than were the non-host-adapted S. typhimurium (Copenhagen) group, but more of the S. typhimurium (Copenhagen) isolates resistant to the other antibiotics tested. None of the isolates produced colicin, but all produced aerobactin. One isolate in each group was encapsulated. All of the S. typhimurium (Copenhagen) and S. dublin isolates contained plasmids, and all of them contained the spvC-homologous sequences. Four of the S. typhimurium (Copenhagen) isolates were able to transfer an R plasmid to a recipient organism by conjugation. One of the five S. dublin isolates, which showed resistance to some of the antibiotics tested, was able to transfer an R plasmid by conjugation. Both groups of isolates invaded cultured epithelial cells to a similar degree after 1 h, but the S. dublin isolates reached significantly higher levels within the cells than did S. typhimurium (Copenhagen) after 9 h. This ability may, in part, explain the association of S. dublin with more severe forms of salmonellosis and prolonged carrier states. Further study of the intracellular growth of these isolates seems warranted.     

禽源沙门菌对四环素的耐药性及耐药基因调查分析

为了更好地了解禽源沙门菌对四环素的耐药性及耐药基因分布,从不同来源的家禽样品中分离沙门菌,调查其对四环素的耐药性以及耐药菌株中8种四环素耐药基因[tet(A)、tet(B)、tet(C)、tet(W)、tet(M)、tet(D)、tet(K)和tet(L)]的携带情况.结果表明,18.8%的沙门菌分离株对四环素耐药,健康成鸡分离株对四环素的耐药性明显高于雏鸡、死胚或病禽分离株;四环素耐药株中tet(A)、tet(B)和tet(M)基因的携带比例分别为73.1%、11.5%和3.8%,说明沙门菌对四环素的耐药机制以tet(A)和tet(B)基因介导的主动外排为主.本研究首次在对四环素耐药的沙门菌中检测到tet(M)基因,说明tet(M)基因在沙门菌对四环素的耐药性方面也具有潜在的作用.     

Phenotypic and Genotypic Characterization of Salmonella enterica in Captive Wildlife and Exotic Animal Species in Ohio,USA

The purpose of this study was to investigate the occurrence, antimicrobial resistance patterns, phenotypic and genotypic relatedness of Salmonella enterica recovered from captive wildlife host species and in the environment in Ohio, USA. A total of 319 samples including faecal (n = 225), feed (n = 38) and environmental (n = 56) were collected from 32 different wild and exotic animal species in captivity and their environment in Ohio. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby–Bauer disc diffusion method. Salmonella isolates were serotyped, and genotyping was performed using the pulsed‐field gel electrophoresis (PFGE). Salmonella was detected in 56 of 225 (24.9%) faecal samples; six of 56 (10.7%) environmental samples and six of 38 (15.8%) feed samples. Salmonella was more commonly isolated in faecal samples from giraffes (78.2%; 36/46), cranes (75%; 3/4) and raccoons (75%; 3/4). Salmonella enterica serotypes of known public health significance including S. Typhimurium (64.3%), S. Newport (32.1%) and S. Heidelberg (5.3%) were identified. While the majority of the Salmonella isolates were pan‐susceptible (88.2%; 60 of 68), multidrug‐resistant strains including penta‐resistant type, AmStTeKmGm (8.8%; six of 68) were detected. Genotypic diversity was found among S. Typhimurium isolates. The identification of clonally related Salmonella isolates from environment and faeces suggests that indirect transmission of Salmonella among hosts via environmental contamination is an important concern to workers, visitors and other wildlife. Results of this study show the diversity of Salmonella serovars and public health implications of human exposure from wildlife reservoirs.     

动物源大肠杆菌及沙门氏菌抗药性的快速检测

利用本室自主研制的新型96点阵药敏检测盒检测山东地区动物源大肠杆菌、沙门氏菌的药物敏感性,试验结果表明,大肠杆菌对氨苄西林和喹诺酮类药物的抗药率达98%以上,禽源大肠杆菌的抗药率高于猪源大肠杆菌,猪源大肠杆菌的抗药谱广于禽源大肠杆菌;沙门氏菌抗药率略低于大肠杆菌,但同样呈现多重抗药,主要集中在5抗-7抗和13抗-14抗两个范围。96点阵抗生素药敏检测盒是适合于试验室进行大规模抗药性监测的新工具,具有简易、准确、快速、大通量、节约的优点,为临床治疗中抗生素的使用、细菌病的治疗提供了技术保障,从而达到避免盲目使用抗生素,降低细菌抗药率的目的。     

食品动物源沙门氏菌质粒介导喹诺酮类耐药基因的检测与分析

为了解食品动物源沙门氏菌质粒介导喹诺酮类耐药性(Plasmid-mediated quinolone resistance,PMQR),采用微量肉汤稀释法和PCR方法,检测了316株食品动物源沙门氏菌对20种抗菌药物的敏感性,以及菌株中PMQR基因的携带率.结果显示:316株沙门氏菌对20种抗菌药物呈不同程度的耐药性,95.57％菌株为多重耐药菌;316株菌中未检出qnrA、qnrC、qnrD、qnrS和qepA基因,7.91％菌株检出qnrB基因,15.19％菌株检出aac(6 ′ )-Ib-cr基因,7.91％菌株检出oqxA基因,8.86％菌株检出oqxB基因,这是首次在沙门氏菌中发现oqxAB基因;98.11％PMQR阳性菌同时携带2种及以上的耐药基因,呈8～17耐的多重耐药性,其中以qnrB和aac(6′)-Ibcr基因型为主;53株PMQR阳性菌分属于5种不同的基因型,耐药表型或耐药基因型不同的菌株却有相同的PFGE谱型.本次检测的316株食品动物源沙门氏菌耐药较为严重;菌株主要携带qnrB、aac(6 ′ )-Ib-cr及oqxAB基因;不同来源菌株存在同一耐药克隆株的流行.     

宏基因组测序分析野生林麝瘤胃、小肠和大肠微生物组成和抗生素抗性基因

本试验旨在研究野生林麝(Moschus berezovskii)瘤胃、小肠和大肠微生物组成和抗生素抗性基因.采集野生林麝消化道3个区段(瘤胃、小肠和大肠)的内容物进行宏基因组测序,并进行常规物种注释和抗生素抗性基因功能注释.结果表明:3个区段共有优势菌门为厚壁菌门(Firmicutes)和变形菌门(Proteobact...     

Campylobacter spp., Salmonella spp., Verocytotoxic Escherichia coli,and Antibiotic Resistance in Indicator Organisms in Wild Cervids

Faecal samples were collected, as part of the National Health Surveillance Program for Cervids (HOP) in Norway, from wild red deer, roe deer, moose and reindeer during ordinary hunting seasons from 2001 to 2003. Samples from a total of 618 animals were examined for verocytotoxic E. coli (VTEC); 611 animals for Salmonella and 324 animals for Campylobacter. A total of 50 samples were cultivated from each cervid species in order to isolate the indicator bacterial species E. coli and Enterococcus faecalis/E. faecium for antibiotic resistance pattern studies. Salmonella and the potentially human pathogenic verocytotoxic E. coli were not isolated, while Campylobacter jejuni jejuni was found in one roe deer sample only. Antibiotic resistance was found in 13 (7.3%) of the 179 E. coli isolates tested, eight of these being resistant against one type of antibiotic only. The proportion of resistant E. coli isolates was higher in wild reindeer (24%) than in the other cervids (2.2%). E. faecalis or E. faecium were isolated from 19 of the samples, none of these being reindeer. All the strains isolated were resistant against one (84%) or more (16%) antibiotics. A total of 14 E. faecalis-strains were resistant to virginiamycin only. The results indicate that the cervid species studied do not constitute an important infectious reservoir for either the human pathogens or the antibiotic resistant microorganisms included in the study.     

欧美大麦种质资源在甘肃的生态适应性评价

以20世纪80年代以来甘肃农垦系统从欧洲和北美洲引进的524份大麦种质或品种资源为试验材料,对供试品种(系)的生育期、幼苗习性、抗逆性等进行了多年的观察记载,对株高、穗长、穗粒数、千粒重等性状进行了考种观察,系统地研究了不同品种的生长发育规律、农艺性状特点、产量性状等,并对部分品种的品质指标进行了测定.研究发现:从欧美等国引进的优质大麦资源和品种,在甘肃一年一熟地区表现出综合农艺性状好,适应性和抗逆性强,优质丰产,千粒重高,籽粒饱满,筛选率、发芽率、浸出率高,蛋白质含量较低,符合啤酒酿造的品质要求;北美洲品种植株较高,茎秆细软,易倒伏;欧洲品种表现株矮,茎秆中粗,抗倒伏性较强,德国品种中有30%的品种易感条纹病;欧美品种普遍表现较早熟,有利于抵抗甘肃河西产区大麦生育后期干热风造成的危害;欧美品种分蘖力强,穗大粒多,千粒重较高,均与原生态条件下的表现一致,适合在甘肃河西走廊、引黄灌区及同类型生态区直接栽培推广,且表现出产量较高,适应性、抗逆性强,也可作为杂交亲本材料加以利用,如Harrington、B1202、Steffi、Riviera等.     

Identification of a Plasmid‐Mediated Quinolone Resistance Gene in Salmonella Isolates from Texas Dairy Farm Environmental Samples

A recent increase in plasmid‐mediated quinolone resistance (PMQR) has been detected among Salmonella isolated from humans in the United States, and it is necessary to determine the sources of human infection. We had previously isolated Salmonella from dairy farm environmental samples collected in Texas, and isolates were tested for anti‐microbial susceptibility. Two isolates, serotyped as Salmonella Muenster, showed the discordant pattern of nalidixic acid susceptibility and intermediate susceptibility to ciprofloxacin. For this project, whole‐genome sequencing of both isolates was performed to detect genes associated with quinolone resistance. The plasmid‐mediated qnrB19 gene and IncR plasmid type were identified in both isolates. To our knowledge, this is the first report of PMQR in Salmonella isolated from food animals or agricultural environments in the United States.     

屠宰猪肠道沙门氏菌的分离鉴定、耐药性分析及致病性试验

为了解广西南宁市猪源沙门氏菌的污染状况、耐药状况及致病力情况,在南宁市某生猪屠宰场随机直接从131头屠宰猪的肠道采集样品,采用鉴别培养基分离,生化鉴定的方法对样品中的沙门氏菌进行分离鉴定,并采用标准K-B纸片法对分离菌株进行25种抗生素敏感试验,最后对分离株进行小白鼠致病性试验。结果从131份屠宰猪的肠道中共分离到沙门氏菌45株,检出率为34.35%;其中鼠伤寒沙门氏菌14株,甲型副伤寒杆菌2株,肠炎沙门氏菌3株。45株分离菌株全部耐药,耐药率高达100%,其中44株为多重耐药菌株,占97.78%。45株沙门氏菌中有40株对小白鼠具有致病性,致病率达88.89%。这表明南宁市的屠宰猪存在一定程度的沙门氏菌污染,并且分离菌株存在较严重的耐药现象以及具有较强的致病性。应采取有效措施控制沙门氏菌在猪群中的污染和限制抗生素在养猪过程中的使用并严格遵守休药期,以减少细菌耐药性的产生,保障猪肉及猪肉制品的食品安全。     

内蒙古地区奶牛源致病性沙门氏菌耐药性分析及ESBLs基因检测

为研究内蒙古地区奶牛源致病性沙门氏菌的耐药特性及ESBLs基因流行特征,试验采用微量肉汤稀释法测定了22种兽医临床常用抗菌药物对临床分离沙门氏菌的最低抑菌浓度(MICs),并对其多重耐药特性进行了分析;采用PCR法对具有β-内酰胺类药物耐药表型的菌株进行了8种动物源沙门氏菌常见ESBLs基因的检测。结果显示,内蒙古地区奶牛源致病性沙门氏菌对甲氧苄啶(97.4%)及磺胺甲基噁唑(94.7%)的耐药率最高,对多数β-内酰胺类、氨基糖甙类、氯霉素类及四环素类药物的耐药性也较为严重(耐药率为40%~80%),所有菌株对氟喹诺酮类药物均敏感;菌株的多重耐药率为94.7%,有29株菌(76.3%)同时对6类抗菌药物具有耐药性;35株对β-内酰胺类药物耐药的菌株中,有30株(85.7%)为ESBLs基因阳性,共检出6种ESBLs基因,其中CTX-M型基因检出率最高(40.0%),未检出SHV和PSE型基因;共发现15种ESBLs基因型,9种ESBLs基因型组合,有16株菌(45.7%)同时携带两种或两种以上ESBLs基因。结果表明,内蒙古地区奶牛源致病性沙门氏菌对兽医临床常用抗菌药物的耐药性较为严重,且ESBLs基因的流行模式较为复杂,提示兽医临床抗菌药物不合理使用可能是造成该地区奶牛源沙门氏菌耐药性产生的原因。     

Analysis of Antimicrobial Resistance and Detection of ESBLs Genes of Pathogenic Salmonella Isolates from Dairy Cows in Inner Mongolia

The aim of the present study was to investigate the characteristics of antimicrobial resistance and prevalence of ESBLs genes of Salmonella isolates from dairy cows in Inner Mongolia.Micro-dilution broth method recommended by CLSI was used to determine the MICs of 22 antimicrobial agents commonly employed in veterinary clinic against the 38 Salmonella isolates.PCR analysis was carried out to detect the presence of 8 ESBLs genes mostly observed in animal origin Salmonella in the isolates with resistance to at least one β-lactam antibiotics, and the features of multi-resistance of the isolates were also analyzed.The results showed that most Salmonella isolates were resistant to trimethoprim(97.4%), sulfamethoxazole(94.7%), and to most of the β-lactam, aminoglycosides, chloramphenicol and tetracycline antibiotics with the resistance rate ranging from 40% to 80%, however, all of the isolates were sensitive to fluoroquinolone drugs.76.3%(n＝29) of the isolates were simultaneously resistant to 6 categories antibiotics and the multi-resistance rate was 94.7%. 85.7%(n＝30) of the β-lactam antibiotics resistant isolates were ESBLs genes positive.Of the six genotype of ESBLs genes found in this study, CTX-M (40.0%) was the mostly encountered ESBLs gene, however, the SHV and PSE types gene were absent in the isolates.A total of fifteen genotypes of the ESBLs genes and nine ESBLs genes combinations were observed in this study, and 16 isolates (45.7%) simultaneously contained two or more than two ESBLs genes.It was indicated that the current situation of the resistance of the Salmonella isolates from dairy cows in Inner Mongolia to the commonly used antimicrobial agents in veterinary clinic was serious, and the prevalence pattern of the ESBLs genes in the isolates was complex, suggesting that the irrational employment of the antibiotic in the treatment of animal infectious diseases was the crucial reason causing the antimicrobial resistance of the isolates.