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1.
Salmonella isolates (n = 209) obtained from food animals and foods in Alberta during 1996 through 1999 were tested for sensitivity to 17 antimicrobials. Of the 3553 antimicrobial susceptibility tests on Salmonella isolates, 11.8% were positive for resistance. These isolates were commonly resistant to tetracycline (35.4%), streptomycin (32.5%), sulfamethoxazole (28.7%), ticarcillin (27.3%), and ampicillin (26.8%). Resistance to at least 1 antimicrobial was observed in 112 isolates (53.6%). Salmonella Typhimurium, S. Typhimurium var. Copenhagen, and S. Heidelberg were the most common serovars among isolates resistant to individual antimicrobials and multiple antimicrobials. The most common profile of multiple-antimicrobial resistance was that which included resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline, and ticarcillin. The proportions of isolates that were resistant to antimicrobials were greater among bovine isolates of Salmonella than among poultry isolates, and this difference was greater among isolates from veterinary diagnostic sources than among those from monitoring sources.  相似文献   

2.
Antibiotics are used in food animal production to treat diseases and also to improve performance. Antibiotics are not used on all farms, and antibiotic resistance is occasionally found on farms that do not use antibiotics. Rendered animal protein products are often included in poultry feeds and could potentially serve as a source of antibiotic-resistant bacteria. One hundred sixty-five rendered animal protein products from cattle, poultry, and fish were aseptically collected from poultry feed mills. Fifty-five percent of the poultry meal samples had detectable levels of gram-negative bacteria ranging from 40 to 10,440 colony-forming units/g of sample. Poultry meal and meat and bone meal had the greatest number of samples with bacteria resistant to five or more antibiotics. A high percentage of feed samples (85%) contained bacteria resistant to amoxicillin, ampicillin, clavulanic acid, or cephalothin, whereas few samples contained bacteria resistant to ciprofloxacin, kanamycin, or trimethoprim/sulfamethoxazole. Acinetobacter calcoaceticus, Citrobacter freundii, and Enterobacter cloacae were the most commonly isolated antibiotic-resistant bacteria. Isolation for Salmonella was also performed, with 14% of the meat and bone meal samples containing Salmonella sp. Only one of the meat and bone meal isolates, Salmonella livingstone, was resistant to five or more antibiotics. Many of the antibiotic-resistant bacteria contained integrons, genetic elements that mediate multiple drug resistance.  相似文献   

3.
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鉴定阳性菌落进行沙门氏菌血清分型;同时,对鉴定出的沙门氏菌进行12种抗生素耐药性分析。结果显示:55个样品池中,沙门氏菌阳性检出率为18.18%;猪禽屠宰场之间沙门氏菌污染率无显著差异(P>0.05),而不同类型样品之间差异显著(P<0.05),其中排污池污泥(75.00%)、土壤(33.33%)和屠宰车间(23.53%)污染率较高;猪屠宰场沙门氏菌优势血清型为鼠伤寒沙门氏菌(S.typhimurium),而禽屠宰场为肠炎沙门氏菌(S.enteritis);所有分离菌株对阿莫西林、氨苄西林2种抗生素完全抗药,对亚胺培南完全敏感,对头孢曲松、头孢他啶、头孢噻吩、氨曲南4种抗生素高度敏感。结果表明:猪禽屠宰场环境中,沙门氏菌污染较为严重,污泥、土壤和屠宰车间是沙门氏菌污染扩散的主要环节;猪禽屠宰场污染的沙门氏菌优势血清型并不同,且环境中污染的沙门氏菌都对部分常用抗生素产生了完全抗药。结果提示:应加强猪禽屠宰环节的沙门氏菌污染控制,将污泥、土壤、屠宰车间作为日常消毒的重点;基层应针对猪禽各自的优势血清型菌株,选用高度敏感抗生素进行沙门氏菌病防治。  相似文献   

4.
By investigating the prevalence and resistance characteristics of Gram-negative bacteria from organic and conventional kept laying hens against 31 (Campylobacter: 29) different antibiotics using the microdilution method, we determined to what extent different keeping systems influence bacterial resistance patterns. For this purpose, samples from 10 organic and 10 conventional flocks in Bavaria (Germany) were investigated four times between January 2004 and April 2005. Altogether, 799 cloacal swabs and 800 eggs (contents and shells) were examined. The bacterial investigation performed with standardized cultural methods showed prevalence for all bacteria groups in about the same order of magnitude in the two different keeping systems: Salmonella spp. 3.5% (organic ([org])) versus 1.8% (conventional ([con])); Campylobacter spp. 34.8%(org) versus 29.0%(con) and E. coli 64.4%(org) versus 69.0%(con). Coliforms (Citrobacter, Enterobacter, Pantoea) were only isolated in single cases. In eggs, generally less bacteria were detected, predominantly Escherichia; Salmonella and Campylobacter were only scarcely isolated. Salmonella enterica ssp. enterica serovar Typhimurium (n=10) were resistant to up to nine, S. of the serogroup B (n=4) up to six antibiotics. All tested Salmonella (n=23) proved to be resistant to spectinomycin. Escherichia coli (n=257(org) and 276(con)) from organic layers showed significant lower resistance rates and higher rates of susceptible isolates to nine agents, namely amoxicillin/clavulanic acid, ampicillin, cefaclor, cefoxitin, cefuroxime, doxycycline, mezlocillin, neomycin and piperacillin. In contrast, only two antibiotics turned out to be more effective in conventional isolates (gentamicin and tobramycin). In the case of Campylobacter jejuni (n=118(org) and 99(con)), statistically significantly better rates were observed for isolates from organic flocks concerning imipenem and amoxicillin/clavulanic acid, whereas fosfomycin was more potent in strains from conventional flocks. Results of this study indicate that both resistance rates and mean minimum inhibitory concentrations of bacteria isolated from organic keeping systems have lower values than those from conventional ones, particularly recognizable for E. coli. Thus, organic livestock farming with its restrictions and additional requirements contributes to further effectiveness of antibiotics.  相似文献   

5.
The study objective was to describe and evaluate antimicrobial resistance profiles in Salmonella isolated from Alberta swine finishing farms. Salmonella isolates (n = 322) were obtained from 192 fecal and 84 environmental samples of the 60 Salmonella-positive swine finishing farms. Isolates were classified susceptible, intermediate or resistant based on NCCLS guidelines. More than half of the isolates (53.4%) were susceptible to all of the 18 antimicrobials in the testing panel. No resistance was observed to amikacin, amoxicillin/clavulanic acid, cefoxitin, ceftiofur, ceftriaxone, cephalothin, ciprofloxacin, imipenem or nalidixic acid. Less than 1% of isolates were resistant to apramycin, gentamicin and trimethoprim/sulfamethoxazole. Higher frequencies of resistance were observed for chloramphenicol (4.7%), ampicillin (7.8%), kanamycin (11.8%), sulfamethoxazole (21.1%), streptomycin (25.5%) and tetracycline (38.8%). Eleven Salmonella serovars had isolates with resistance to > or =3 antimicrobials. The most frequently resistant serovar was Salmonella Derby, with 27 (38.0%) isolates resistant to > or =3 antimicrobials, including resistance to five and six antimicrobials. An absence of resistance to cephalosporins and fluoroquniolones and a low proportion of isolates resistant to amikacin, amoxicillin/clavulanic acid, apramycin, gentamicin and trimethoprim/sulfamethoxazole are encouraging findings from public health and animal health perspectives. Frequent resistance observed for ampicillin, kanamycin, sulfamethoxazole, streptomycin and tetracycline, antimicrobials commonly used in veterinary medicine for decades, indicates an urgent need to utilize these antimicrobials more prudently if their benefits are to be preserved.  相似文献   

6.
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.  相似文献   

7.
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...  相似文献   

8.
Salmonella isolates from random-source cats designated for use in research were examined for antibiotic susceptibilities and the presence of plasmids containing R factors. The serotypes studied were Salmonella derby, S typhimurium, S anatum, S enteritidis, and S bredeney. Eighty percent of the isolates were resistant to one or more antibiotics. The greatest frequency of resistance was to streptomycin. The majority of the salmonella isolates transferred all or a part of their antibiotic resistance to an Escherichia coli K-12 recipient. Thermosensitive R factors were found in two S typhimurium isolates.  相似文献   

9.
The purpose of this study was to investigate the molecular types and antimicrobial resistance of Salmonella isolated from pigeon in Shanghai from 2011 to 2014. A total of 92 fecal samples were collected from markets. XLD plate and Salmonella chromogenic medium were used to isolate suspected Salmonella colonies, and then determined the number of Salmonella through gram staining and biochemical tests. Among them, 24(26.1%) were positive for Salmonella. Kauffmann-White method and the K-B method were used respectively for serotype identification and susceptibility testing. In result, serological identification showed that 24 isolates from pigeon could be divided into 3 serotypes including S.typhimurium (66.7%), S.agona (25.0%) and S.corvallis (8.3%). Drug susceptibility test showed that 75.0% of the isolates were resistant to one antibiotic at least. The highest level resistance were found for tetracycline as well as sulfisoxazole (62.5%), followed by streptomycin (58.3%), nalidixic acid (50.0%) and ampicillin (20.8%). Multi-drug resistant strains accounted for 62.5% (15), in which the largest number of strains (7, 16.7%) were resistant to four drugs. In addition, isolates were 100.0% susceptible to cefepime, cefotaxime, ceftazidime, imipenem and ofloxacin, but 12.5% were moderately sensitive to the amoxicillin/clavulanic acid and ciprofloxacin. The study showed that Salmonella had a high separation rate of pigeon in Shanghai farmers market and performed serious multidrug resistance, which would bring great challenges and risks to the prevention and control of Salmonella in food, so that the prevalence and drug resistance of Salmonella in pigeon deserved close attention.  相似文献   

10.
为了解上海市农贸市场肉鸽群体中沙门氏菌流行血清型和耐药情况,本试验于2011-2014年间从上海市各区农贸市场采集肉鸽新鲜粪便样本92份,用XLD平板和沙门氏菌属显色培养基分离疑似沙门氏菌,革兰氏染色镜检并进行生化试验,共获得沙门氏菌24株,分离率为26.1%。采用Kauffmann-White法和K-B纸片法对24株沙门氏菌进行血清型鉴定和16种抗生素的药敏试验。血清型鉴定显示,24株沙门氏菌可分为鼠伤寒（66.7%）、阿贡纳（25.0%）和科瓦利斯（8.3%）3种血清型。药敏试验结果显示,有75.0%（18株）的分离株表现出不同程度耐药,其中分离株对四环素和磺胺异唑耐药率最高,均达到62.5%,其次为链霉素（58.3%）、萘啶酸（50.0%）、氨苄西林（20.8%）。多重耐药菌株15株（62.5%）,耐4种抗菌药物的菌株最多,占16.7%（7株）。另外,分离菌株对头孢吡肟、头孢噻肟、头孢噻甲羧肟、亚胺培南、氧氟沙星等5种药物的敏感率为100.0%,对奥格门丁和环丙沙星有12.5%的中介敏感率。本研究结果表明,上海市肉鸽中沙门氏菌的携带率较高,且菌株多重耐药现象较严重,这为食品中沙门氏菌的防控工作带来较大的挑战和风险,肉鸽沙门氏菌的流行和耐药情况应值得密切关注。  相似文献   

11.
Antibacterial drug resistance among 219 salmonella isolates recovered during 1974 from poultry and poultry environments at the various production stages of broiler chickens in three integrated Ontario companies are recorded. All isolates were susceptible to ampicillin, trimethroprim-sulfamethoxazole complex, furazolidone, cephaloridine and amoxicillin. A relative increase in resistance to tetracycline and streptomycin with an accompanying decrease in resistance to triple sulfa compound was recorded when compared to a previous investigation of avian salmonella isolates in Ontario. The percentage and patterns of antimicrobial resistance were comparable at the various stages of production. Resistance to tetracycline and streptomycin was the most common pattern found among both Salmonella typhimurium and other serotypes. A notably high prevalence of resistance was found among Salmonella enteritidis isolates including some isolates with R factors for chloramphenicol resistance. This latter finding is of particular concern because of the high prevalence of this serotype in poultry and in human salmonellosis.  相似文献   

12.
Resistance to 20 antibiotics of 128 Salmonella and 97 Escherichia coli isolates from various registrable farm feeds was determined. A high frequency of comparatively low levels of resistance was found in both the Salmonella and E. coli isolates. This, together with an elevated frequency of multiple resistance, indicates that problems related to an effective transfer in bacterial populations of resistance to certain antibiotics are a distinct possibility. The addition of antibiotics, such as penicillin and tetracyclines, to animal feeds can create conditions for rapid selection amongst bacteria resistant to antibiotics. The numbers of resistant bacteria in the animal environment may be increased and may lead to the development of veterinary and human health problems from the possible transfer of antimicrobial resistance from animal pathogens to human pathogens or spreading in the human population of animal pathogens resistant to antibiotics. There is a need for caution in the use of antibiotics, particularly in animal feeds. Extended survey of, and epidemiological research on, farm feeds, manufacturing mills and animal production units are emphasized.  相似文献   

13.
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...  相似文献   

14.
This study investigated the occurrence and antimicrobial resistance profiles of Escherichia coli and Salmonella sp. isolated from swine samples submitted to the Minnesota Veterinary Diagnostic Laboratory (MVDL) in Saint Paul, Minnesota from 1995 to 2004. During this time period, a total of 5072 E. coli and 2793 Salmonella sp. was isolated. Most of these isolates were found to be resistant to the tetracycline and beta-lactam group of antibiotics. Resistance to spectinomycin was also frequently observed. An increasing trend in ampicillin resistance and a decreasing trend in apramycin resistance were seen in both pathogens, although ampicillin resistance was relatively higher in E. coli than in Salmonella. Aminoglycoside (amikacin) and quinolone (enrofloxacin) were the only antimicrobials to which minimum or no resistance was observed. The resistance of pig pathogens to several antibiotics indicates the need to routinely monitor the use of these antimicrobials and their associated resistance in pig populations.  相似文献   

15.
The objective of this study was to compare Salmonella prevalence and antimicrobial resistance between pasture and conventional poultry farms. We collected the first Salmonella prevalence and antimicrobial resistance data on pasture poultry farms. Fecal droppings were collected from 31 farms from Wisconsin (nine farms from each production type) and the Southeast (North Carolina, Virginia, and South Carolina; five conventional and 10 pasture poultry farms) in a 1-yr period. The specimens were cultured for Salmonella and tested for resistance to 12 antimicrobials. A univariate analysis was conducted to determine the significant differences in prevalence and resistance. At the farm level, no significant difference in Salmonella prevalence was found on 33% pasture and 47% conventional poultry farms (P= 0.4928). On an individual specimen level, flocks reared conventionally had higher prevalence than in pasture (P < 0.0001). Of all the isolates found to have resistance, 80% were from the Southeast. Of all the pasture isolates tested, 5% (8 of 162) were resistant to ceftriaxone, which is higher than previously reported from any production setting. None of the isolates from conventional flocks showed resistance to ceftriaxone. Multidrug resistance (resistance to three or more classes of antimicrobials) was found in 69% of the isolates from conventional farms and 11% on pasture farms in the Southeast (P < 0.0001), with the predominant resistance type of AmCSSuTeAx (ampicillin, chloramphenicol, streptomycin, sulfasoxazole, tetracycline, amoxicillin/clavulanic acid; 62%). About 5% of the pasture isolates from the Southeast showed the AmAxCFCRO (ampicillin, amoxicillin/clavulanic acid, cephalothin, ceftriaxone) multidrug resistance pattern. None of the isolates from Wisconsin were found to be multidrug resistant.  相似文献   

16.
Salmonella belonging to 47 serotypes was isolated from animals at the University of California Veterinary Medical Teaching Hospital during the years 1974 to 1983. Salmonella belonging to 12 serotypes accounted for 89% of the 725 isolates. Salmonella typhimurium (including var copenhagen) was the most commonly isolated serotype, but during 1981 to 1983, S krefeld and S saint-paul were predominant. Certain serotypes seemed to be isolated more frequently from extraintestinal sources (S typhi-suis, S dublin). Although resistance to ampicillin, kanamycin, neomycin, streptomycin, and sulfonamides was common (greater than 60% of the isolates were resistant), resistance to chloramphenicol, gentamicin, and trimethoprim-sulfonamides was infrequent, except for isolates of S krefeld and S saint-paul.  相似文献   

17.
Between May and September 2004, fecal samples from various wildlife species admitted to two rehabilitation centers in Ohio were cultured for Salmonella enterica and Escherichia coli O157:H7. Eight of 71 (11%) samples, including specimens from three opossums (Didelphis virginiana), two gray squirrels (Sciurus carolinensis), a woodchuck (Marmota monax), a Harris hawk (Parabuteo unicinctus), and a screech owl (Otus asio) tested positive for Salmonella serovars Braenderup, Senftenberg, Oranienburg, and Kentucky. The Salmonella Oranienburg isolates were indistinguishable by pulsed-field gel electrophoresis. Most isolates were susceptible to commonly used antibiotics; however, the Salmonella Kentucky isolate was resistant to multiple beta-lactam antibiotics (amoxicillin/clavulanic acid and ampicillin), cefoxitin, and ceftiofur, a third-generation cephalosporin. Escherichia coli O157:H7 was not isolated from any sample. Transmission of Salmonella from wildlife may occur between animals at rehabilitation centers.  相似文献   

18.
The aim of the study was to isolate gram-positive cocci from cows with mastitis and to determine their resistance to beta-lactamic antibiotics. Eight hundred and nine strains were isolated and identified as staphylococci (n=516), streptococci (n=199) and enterococci (n=94) from sub-clinical and clinical cases of bovine mastitis in Lithuania. The most common causative agents of udder disease included: S. epidermidis (n=176), S. aureus (n=176), S. agalactiae (n=134), S. hyicus (136) and E. hirae (n=68). Isolates were analysed for antimicrobial resistance to penicillin, ampicillin, amoxicillin, cephalothin, cephalexin, amoxicillin + clavulanate. The susceptibility patterns were analysed using the agar disk diffusion method. S. aureus showed the highest level of resistance to amoxicillin (81.3%), penicillin (76.7%) and ampicillin (78.4%). The corresponding values for CNS strains were 59.7%, 59.7% and 50.6% against penicillin, ampicillin and amoxicillin respectively. Streptococci were the most frequently resistant to amoxicillin (29.3%), and enterococci to penicillin (27%), amoxicillin (27.5%) and amoxicillin/clavulanic acid (23.8%). The resistance of all tested mastitis pathogens to aminopenicillins and penicillin highly correlated (r=0.83). Compared with other antibiotics, amoxicillin and clavulanic acid combination tended to be more effective (p<0.05) against all tested bacteria in vitro. However, S. aureus, in 38.1% of cases, was resistant to this combination of antimicrobials. This study demonstrates that S. epidermidis, S. aureus, S. hyicus, S. agalactiae and E. hirae remain the most frequent mastitis causative agents on Lithuanian cattle farms. The highest resistance in vitro to penicillins was demonstrated by S. aureus, S. hyicus and S. intermedius. Resistance to cephalosporins remains low, irrespective of bacterial species of gram-positive cocci.  相似文献   

19.
Salmonella typhimurium-associated conjunctivitis in an adult female cat was characterized by epiphora and blepharospasm. The cat also harbored intestinal S typhimurium, as did one other cat in the same shipment of 7 cats obtained from a commercial cat dealer. The 3 isolates were resistant to ampicillin, cephaloridine, cephalothin, streptomycin, triple sulfonamides, and tetracycline. All 3 isolates were capable of transferring a part of the antibiotic resistance pattern to an Escherichia coli K-12 recipient. Salmonella were not recovered from the conjunctiva or fecal flora of either cat after 10 days of therapy with chloramphenicol.  相似文献   

20.
为掌握上海市沙门氏菌在农贸市场和超市禽肉制品和活禽中的污染状况、流行血清型和耐药情况,本试验从320份2012年采集的禽肉样本(240份)和活禽泄殖腔棉试子(80份)中共分离鉴定出沙门氏菌70株,阳性率为21.9%。血清型鉴定结果表明,共鉴定出11种不同的血清型,其中肠炎沙门氏菌占47.1%、印第安纳沙门氏菌占17.1%、鼠伤寒沙门氏菌和德尔卑沙门氏菌均占8.6%。通过纸片法对这70株沙门氏菌进行了16种常用抗菌药物的药敏试验,结果表明,沙门氏菌对奈啶酸耐药率最高,达75.7%,对磺胺异唑、链霉素和氨苄西林耐药率较高,分别为60.0%、60.0%和51.4%。除亚胺培南外,其他药物均有不同程度的耐药菌株。有40株(57.1%)沙门氏菌呈多重耐药表型,耐药性最强的菌株可以对14种抗菌药产生耐药性。本研究对沙门氏菌病的防控及指导临床合理用药具有重要的现实意义。  相似文献   

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