首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
BackgroundThere are only narrow insights regarding the antimicrobial resistance of pathogens in poultry environment in India and its transmission to humans. The use of antimicrobials in food animal production is not properly regulated in India. So, many clinically important antimicrobials are used indiscriminately.ObjectiveOur aim was to do a comparative analysis of antibiotic resistance in Escherichia coli isolates from poultry environment and UTI patients.MethodologyTwo poultry farms each from six areas in Muvattupuzha region of the state of Kerala in India were selected for the study. From each farm, samples of fresh fecal matter, litter from inside the shed, litter from outside the shed, nearby agricultural soil and control soilwere collected. E. coli was isolated from each sample, and antimicrobial susceptibility testing of E. coli was done with fifteen antibiotics. Antibiograms of UTI patients were collected from the tertiary care hospital included in the study and those were compared with the antibiograms of poultrysamples.ResultAll samples were resistant to ampicillin, amoxicillin, meropenem and tetracycline. Similar resistance pattern in poultry environment and UTI patients was seen for antibiotics such as ampicillin, amoxicillin, amikacin, and ofloxacin. A statistically significant difference (p < .00601) was established in the total number of isolates resistant to various antibiotics from areas near to farms compared to those away from farms.ConclusionE. coli were resistant not only to extended spectrum beta lactams but also to carbapenems which might have disseminated to environment where litter was used as manure. This might be due to irrational use of antibiotics in chicken and poultry feed as growth promoter.  相似文献   

2.
Poultry feed is at the start of the food safety chain in the "farm-to-fork" model, and might serve as a source of antimicrobial resistant bacteria present in poultry meat. Antimicrobial resistance was investigated in 1137 enterococci and 163 Escherichia coli strains recovered from 23 samples of commercial broiler feed and 66 samples of raw feeding materials taken over half a year timespan. Enumeration of enterococci and E. coli were also performed using traditional plating and fluorescent in situ hybridisation methods. Viable enterococci were detected in all feed samples and in 66% of samples of separate feed ingredients, while E. coli was present in 50% and 32% of feed and raw feeding materials, respectively. The median values (50th percentile) for plate and FISH counts for feeds were, respectively, 2.70 log CFU/g and 5.52 log cells/g for enterococci, and 0.15 log CFU/g and 6.00 log cells/g for E. coli. Among enterococci recovered from feed ingredients, resistance to rifampicin, erythromycin, nitrofurantoin, tetracycline, and ciprofloxacin was found in 59.8%, 21.6%, 21.2%, 18.0% and 6.9% of the isolates, respectively. A considerable proportion of the enterococci isolates obtained from broiler feed displayed resistance to tetracycline (69.1%), rifampicin (58.5%), erythromycin (52.9%) and nitrofurantoin (36.2%). Lower percentage of resistance was observed to chloramphenicol (4.6%), ciprofloxacin (3.9%), vancomycin (1.9%) and ampicillin (1.2%). Among E. coli recovered from feed ingredients and poultry feeds, resistance to ampicillin, tetracycline and streptomycin was found in 22.9%, 27.6% and 19.0% and in 22.4%, 41.4% and 17.0% of the isolates, respectively. These data show that feedstuffs and poultry feeds are extensively contaminated by resistant enterococci and, in a lesser extent, by E. coli, thus leading to their introduction in the farm environment.  相似文献   

3.
The species population of enterococci isolated from four poultry houses for six grow-outs on one farm was determined. Two houses on the farm were control houses and did not use any antimicrobials, while two other houses on the farm used flavomycin, virginiamycin, and bacitracin during different poultry grow-outs. Litter, chick boxliners, feed, and poultry carcass rinses were obtained from each house and cultured for the presence of enterococci. Nine species of enterococci (Enterococcusfaecalis, E. faecium, E. avium, E. casselifiavus, E. cecorum, E. durans, E. gallinarum, E. hirae, and E. malodoratus) were identified from the study. Enterococcus faecalis was isolated more frequently from chick boxliners (n=176; 92%) and carcass rinses (n=491; 69%), whereas E. faecium was found more frequently in litter (n=361; 77%) and feed (n=67; 64%). Enterococcus faecalis (n=763; 52%) and E. faecium (n=578; 39%) were isolated most often from the farm and houses, regardless of antimicrobial treatment. Fifty-two percent of E. faecalis and 39% of E. faecium were isolated from both control (n=389 and 295, respectively) and treatment (n=374 and 283, respectively) samples. This study indicates that antimicrobial usage on this farm did not alter the resident population of enterococci.  相似文献   

4.
The aminoglycoside apramycin has been used widely in animal production in China since 1999. This study was aimed to investigate the resistance pattern of apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China during 2004–2007 and to determine whether resistance to apramycin was mediated by plasmid containing the aac(3)-IV gene and the mode for the transfer of genetic information between bacteria of farm animals and farm workers. Thirty six E. coli isolates of swine, chicken, and human origins, chosen randomly from 318 apramycin-resistant E. coli isolates of six farms in northeastern of China during 2004–2007, were multi-resistant and carried the aac(3)-IV gene encoding resistance to apramycin. Conjugation experiments demonstrated that in all 36 cases, the gene encoding resistance to apramycin was borne on a mobilisable plasmid. Homology analysis of the cloned aac(3)-IV gene with the sequence (accession no. X01385) in GenBank showed 99.3% identity at a nucleotide level, but only with a deletion of guanosine in position 813 of the gene in all 36 cases. The results indicted that resistance to apramycin in these isolates was closely related to aac(3)-IV gene. Therefore, the multi-resistance of E. coli could complicate therapeutic practices for enteric infections in both farm animals and human.  相似文献   

5.
The objective of this longitudinal ecological study was to examine the relationship between the prevalence of antibiotic-resistant (AR) commensal Escherichia coli isolates from both monthly human wastewater and composite swine fecal samples and the concurrent aggregated monthly antibiotic use recorded within each host species in multi-site vertically integrated swine and human populations. In addition, human vocation (swine worker versus non-swine worker), swine production group, and season were examined as potential confounding variables. Human and swine E. coli isolates (n = 2469 human and 2310 swine, respectively) were tested for antimicrobial susceptibility using a commercial broth microdilution system. In the human population, among swine workers the relative odds of tetracycline resistance were increased significantly for tetracycline (class) drug use at the third quartile and above of mean monthly dosage (MMD) (OR = 1.8) as compared to the referent category (non-use). The relative odds of ciprofloxacin resistance were significantly increased for ciprofloxacin use in non-swine workers (OR = 5.5) as compared to the referent (non-use). The relative odds of tetracycline resistance were increased significantly for chlortetracycline use in medicated feed for the upper tertile of MMD category (OR = 2.9) as compared to the referent category (no use) across all swine production groups. While high variability among seasonal samples over the 3-year period was observed, no common seasonal trends relating to antibiotic use and prevalence of resistance over the 3-year period were apparent. The overall effects of concurrent human and swine antibiotic use on AR E. coli levels were inconsistent and modest in this study.  相似文献   

6.
The prevalence of resistant bacteria in food products in Iceland is unknown, and little is known of the prevalence in production animals. The aim of this study was to investigate the prevalence and genetic relatedness of antimicrobial‐resistant Escherichia coli from healthy pigs and broiler chicken, pork, broiler meat, slaughterhouse personnel and outpatients in Iceland. A total of 419 E. coli isolates were tested for antimicrobial susceptibility using a microbroth dilution method (VetMIC), and resistant strains were compared using pulsed‐field gel electrophoresis (PFGE). All samples were screened for enrofloxacin‐resistant strains with selective agar plates. The resistance rates among E. coli isolates were moderate to high from caecal and meat samples of pigs (54.1% and 28%), broilers (33.6% and 52%) and slaughterhouse personnel (39.1%), whereas isolates from outpatients showed moderate resistance rates (23.1%). Of notice was resistance to quinolones (minimum inhibitory concentrations: nalidixic acid ≥ 32, ciprofloxacin ≥ 0.12 and enrofloxacin ≥ 0.5), particularly among broiler and broiler meat isolates (18.2% and 36%), as there is no known antimicrobial selection pressure in the broiler production in Iceland. The majority (78.6%) of the resistant E. coli isolates was genotypically different, based on PFGE fingerprint analyses and clustering was limited. However, the same resistance pattern and pulsotype were found among isolates from broiler meat and a slaughterhouse worker, indicating spread of antimicrobial‐resistant E. coli from animals to humans. Diverse resistance patterns and pulsotypes suggest the presence of a large population of resistant E. coli in production animals in Iceland. This study gives baseline information on the prevalence of antimicrobial‐resistant E. coli from production animals, and their food products in Iceland and the moderate to high resistance rates emphasize the need for continuing surveillance. Further studies on the origin of the resistant strains and the genetic relatedness of strains of different origin are needed.  相似文献   

7.
This study aims to investigate the genetic diversity of thermotolerant Campylobacter in commercial broiler flocks and in the environment of broiler farms in Belgium. Seven out of 18 investigated flocks became colonized during rearing. Fluorescent amplified fragment length polymorphism (FAFLP), pulsed field gel electrophoresis (PFGE), restriction fragment length polymorphism of the flagellin A gene (flaA-RFLP) and antimicrobial resistance profile (ARP) were used for typing of the isolates. By the combination of FAFLP and PFGE, 22 Campylobacter genotypes could be distinguished. Colonization was almost exclusively with Campylobacter jejuni and unique genotypes were found in each flock. Multiple genotypes were detected in the broilers of 3 flocks, either simultaneously or successively. In 5 flocks, strains that were resistant to at least one antibiotic (mostly tetracycline) were found. The presence of other broiler houses on the farm did not result in a higher probability of colonization. The nipple water was contaminated with the same genotype as the broilers, illustrating its importance for transmission of Campylobacter. The same genotype was detected in a water puddle and in the broiler flock during rearing in 3 flocks. Once, the same genotype was isolated from the ditch water shortly before it was detected in the broilers.  相似文献   

8.
Eleven cattle farms, 8 layer farms, 7 broiler farms and 30 broiler meat samples were investigated in south-eastern Italy throughout 2003 to evaluate the prevalence, the molecular type and antimicrobial resistance of thermophilic Campylobacters. A total of 398 samples were analysed. One Campylobacter isolate for each positive faecal swab and three isolates per positive broiler meat sample were selected for further analysis. Multiplex PCR was performed for species-level identification and PCR-RFLP of the flagellin A gene for genotyping. Resistance to 14 antimicrobials was studied in 188 Campylobacter isolates. Prevalence of campylobacters was high both on farms (100%) and in food samples (73%). On 4/11 cattle farms and on 10/15 poultry farms more than one species was isolated. The presence of more than one genotype was found on 8/11 cattle farms, on 10/15 poultry farms and in 8/22 Campylobacter-positive food samples. High rates of resistance to quinolone were observed: 9/31 (29%) C. jejuni bovine isolates, 4/22 (18%) C. jejuni poultry isolates, and 14/26 (54%) C. coli poultry isolates. Resistance to sulphamethoxazole-trimethoprim was also observed frequently: 18/26 (69%) of the avian C. coli strains, 25/31 (80%) of the C. jejuni strains isolated from poultry and 15/22 (68%) of those isolated from cattle were resistant. There was a significant difference between the rate of resistance to macrolides of C. coli and C. jejuni isolated in poultry, which amounted to 23% and 3%, respectively. This study provided data on the prevalence and antimicrobial resistance of thermophilic campylobacters in south-eastern Italy and confirmed that flaA-typing is an efficient tool to study the epidemiology of Campylobacter strains in short-term investigations.  相似文献   

9.
Fluoroquinolones are used to treat infections caused by Escherichia coli in canine and feline veterinary patients, particularly those infecting the urinary tract. The gyrA gene is a primary target causing fluoroquinolone resistance in Gram negative coliforms, with mutations in codons 83 and 87 generally associated with high-level of resistance E. coli clinical isolates. We have developed a fluorescence resonance energy transfer (FRET) quantitative PCR to identify enrofloxacin-resistance in clinical E. coli isolates that carry mutations in codons 83 and 87 of gyrA. This real-time quantitative PCR assay is rapid, economical, and sensitive compared with cultured antimicrobial susceptibility testing. The assay identified as few as four genome copies per reaction from culture and 19 genome copies in urine. For the 70 isolates tested, the sensitivity was 87.5% (95% CI = 75–95.3%) (n = 42/48), specificity was 100% (95% CI = 87.3–100%) (n = 22/22), whereas accuracy was 91.4% (95% CI = 82.3–97%) (n = 64/70). Furthermore, we were able to accurately differentiate between the wild type and mutants E. coli directly from infected canine urine samples (n = 5) within 2 h. These results were confirmed by sequence alignments of the PCR products and comparison with the susceptibility testing. The FRET-PCR assay appears to have promising clinical application as an early diagnostic tool for rapid and sensitive detection and differentiation of the level of fluoroquinolone resistance among clinical E. coli isolates that may facilitate design of the dosing regimen.  相似文献   

10.
The prevalence of antimicrobial resistant Escherichia coli was tested in symbovine flies and sympatric house martins (Delichon urbica) at a dairy farm. Antimicrobial resistant E. coli was detected in 89% (n = 147) of isolates from flies within a calf barn. Isolates with the same antimicrobial resistance phenotypes, genes, and pulsotypes were found between both fly and calf E. coli isolates, suggesting that the calves were the initial source of the antimicrobial resistant strains in fly isolates. Symbovine flies were considered as important reservoirs of antimicrobial resistant E. coli strains at a dairy farm, due to their intensive contact with cattle feces and manure. House martin fecal samples from the same farm contained 4.5% (n = 393) of antimicrobial resistant E. coli. House martin isolates displayed different macrorestriction profiles than fly isolates and the significance of house martins as a reservoir and vector of antimicrobial resistant E. coli appears low.  相似文献   

11.
An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.  相似文献   

12.
Four dietary factors (ad libitum versus feed restriction, control versus protein restriction at ad libitum feeding, control versus inclusion of lupin as a protein source at ad libitum feeding, and control versus extra vitamin E at ad libitum feeding) were tested in four separate experiments for the effect on diarrhoea. To introduce a diarrhoea-like condition, half of the piglets were challenged with an E. coli O 149 dose of 1 × 108 colony forming units on days one and two after weaning (day of weaning = day zero). All piglets were susceptible since the dams were tested mono-zygotic susceptible to the attachment site of E. coli O 149 in the intestines. Each of the four experiments included 32 piglets from 4 sows. The design was a 2 × 2 factorial with dietary factor and E. coli O 149 challenge as the two factors, each at two levels. The piglets were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. The daily recordings included feed intake, weight and faecal score (from 1 = solid and cloddy to 6 = watery and yellow). Faeces from days 1 to 4 were tested for E. coli strains. In addition, blood was sampled and serum was analysed for antibodies to E. coli, IgG and IgM. Generally the E. coli challenge had no effect on growth and feed intake whereas faecal score and number of faecal haemolytic bacteria increased and faecal dry matter decreased. Feed restriction decreased the weight gain while faecal characteristics were unaffected. An analysis including all four experiments revealed that a feed intake of less than 200 g during the first day after weaning seems to be associated with a relatively high incidence of a post-weaning diarrhoea-like condition. Protein restriction decreased faecal score and increased faecal dry matter while weight gain tended to decrease. Inclusion of lupin affected neither weight gain nor faecal characteristics. Extra vitamin E did not affect weight gain while faecal dry matter decreased, and faecal score and number of faecal haemolytic bacteria increased. The dietary treatments had no effect on the measured immunoglobulins. In conclusion, the studied dietary factors could not alleviate a diarrhoea-like condition and at the same time maintain the growth rate. Furthermore, the results indicate that performance can be improved if piglets achieve a daily feed intake of at least 200 g during the first day after weaning.  相似文献   

13.
Seventy-five 25-day-old broilers were divided into three groups: group I unmedicated and challenged with E coli 078:K80; group F infected and treated with 150 ppm of phosphomycin in their drinking water, and group C acted as a control. Their weights, feed intake, clinical signs, macroscopic lesions, E coli reisolation, and serum biochemistry were compared. Group F showed fewer symptoms and gross lesions than those from group I while the average daily gain, bodyweight, and feed intake were similar to the control group. E coli was reisolated in 32 per cent of the livers and spleens from group I, compared with 4 per cent of liver and 8 per cent of spleens from group F. There was an increase in the levels of total protein and globulins in group I but not in group F. These results provide evidence of the therapeutic efficacy of phosphomycin in the control of an experimental E coli infection in broiler chickens.  相似文献   

14.
Cellulitis caused by Escherichia coli in broilers results in substantial losses to the broiler industry in North America and Europe due to condemnations at slaughter. The objective of this study was to identify cellulitis in broilers in Sri Lanka and to characterize the E. coli from cellulitis and other colibacillosis lesions. Twenty-four farms from the low- and mid-country were selected and bacterial isolations were obtained from 241 birds. Two hundred and ninety-one gross lesions were observed in these 241 birds and 162 E. coli isolates were obtained. Cellulitis was observed in 21% of the birds. Twenty-one per cent of the birds had multiple lesions due to E. coli. The frequency of detection of other disease syndromes was 162 (67%) birds with pericarditis, 26 (11%) airsacculitis, 24 (10%) hepatitis, 12 (5%) perihepatitis, and 16 (7%) polyserositis (a combination of pericarditis, perihepatitis and airsacculitis). Serogroups O78, O2, O85 and O88 were distributed among the 32% of typable E. coli and 81% of isolates were assigned to three biotypes. Forty-four per cent of the E. coli isolates produced aerobactin and 88% demonstrated resistance to the bactericidal effect of normal chicken serum. The majority of the E. coli isolates were resistant to the antibiotics commonly used in poultry. All the E. coli isolates were non-haemolytic and 25% of the isolates produced K1 capsule. This study demonstrated the presence of cellulitis in Sri Lanka and this report describes some of the phenotypic characteristics of the E. coli isolates.  相似文献   

15.
Escherichia coli is a major pathogen of worldwide importance in commercially produced poultry, contributing significantly to economic losses in chickens and turkeys. One hundred thirty-five cases in broilers were examined and cultured for isolation and antimicrobial sensitivity evaluation of E. coli between January 2005 and December 2006. In 103 cases (76.3%) E. coli were isolated and in 32 cases (23.7%) no E. coli growth was observed. Multiple resistances were seen in all isolates. All isolates were uniformly resistant to Tiamuline, Tylosin, and Bacitracin. We observed low levels of resistance to Gentamicin (12%), Kanamycin (0%), and Florfenicol (39%). Percentages of resistance to Tiamuline, Bacitracin, Tylosin, Colistin, and Erythromycin (≥99%); Tetracycline (96%); Oxytetracycline (93%); Flomequine (87%); Neomycine (87%); Lincospectin (79%); Difloxacin (78%); Enrofloxacin (76%); Cotrimoxazole (72%); Chloramphenicol (52%); and Ampicillin (49%) were determined. Our data show high levels of multiresistance among Iranian E. coli isolates. It seems that the pattern of antibiotic resistance of bacteria that are clinically important for the poultry industry should be monitored.  相似文献   

16.
Seventy-six faecal samples were obtained from broilers at slaughterhouse level in Portugal. Samples were inoculated on cefotaxime-supplemented Levine agar plates. Cefotaxime-resistant Escherichia coli isolates were recovered from 32 samples (42.1%), obtaining a total of 34 E. coli isolates (one or two isolates per sample). Susceptibility to 16 antibiotics was studied by disk diffusion method, and 85% of the isolates presented a phenotype of multi-resistance that included antimicrobial agents of at least four different families. Extended-spectrum-beta-lactamases (ESBL) of the TEM and CTX-M groups were detected in 31 ESBL-positive E. coli isolates. Twenty-six isolates harboured the blaTEM-52 gene and two of them also harboured blaTEM-1b. The blaCTX-M-14 gene was identified in three isolates (in association with blaTEM-1b in one of them), and blaCTX-M-32 was demonstrated in two additional isolates. Three of the 34 cefotaxime-resistant isolates (9%) did not produce ESBLs, and two of them presented mutations at positions −42 (C → T), −18 (G → A), −1 (C → T), and +58(C → T) of the promoter/attenuator region of ampC gene. tet(A) and/or tet(B) genes were detected in all 34 tetracycline-resistant isolates, aadA in all 26 streptomycin-resistant isolates; cmlA in 3 of 6 chloramphenicol-resistant isolates, and aac(3)-II or aac(3)-I + aac(3)-IV genes in all 4 gentamicin-resistant isolates. Different combinations of sul1, sul2 and sul3 genes were demonstrated among the 22 trimethoprim–sulfamethoxazole-resistant isolates. Amino acid changes in GyrA and ParC proteins were identified in all 18 ciprofloxacin-resistant isolates. The results of this study indicate that the intestinal tract of healthy poultry is a reservoir of ESBL-positive E. coli isolates.  相似文献   

17.
Antimicrobial resistance (AMR) in the aquatic environment represents an important means of introduction and dissemination of resistance genes, and presence of resistant pathogens in surface waters may pose a public health concern to recreational and drinking water users. The purpose of this study was to explore antimicrobial resistance patterns in water samples collected from the Grand River watershed (southwestern Ontario, Canada) to describe the composition, trends and potential risks of AMR in the aquatic environment. As part of FoodNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), stream water samples were collected bi‐weekly from sampling sites within the Grand River watershed in the Waterloo, Ontario sentinel site and tested for the presence and antimicrobial susceptibility of Salmonella spp. (2005–2013) and generic Escherichia coli (2012–2013). Of all samples tested, 16% of Salmonella and 22% of E. coli isolates were resistant to at least one antimicrobial, including three Salmonella isolates and two E. coli isolates that were resistant to Category I antimicrobials, which are classified as very high importance for the treatment of serious bacterial infections in humans. The greatest proportion of resistant E. coli isolates were observed from the river site upstream of the drinking water intake, while the greatest proportion of resistant Salmonella isolates were from sites upstream in the watershed, and at one recreational water site. Salmonella resistance trends remained fairly stable between 2007 and 2013, with the exception of streptomycin and tetracycline which increased in 2010 and 2013. Continued surveillance of antimicrobial resistance patterns and exploration of risk factor data will allow for a better understanding of resistance transmission in the aquatic environment.  相似文献   

18.
We examined the antimicrobial susceptibility of 848 Escherichia coli isolates from 237 feces samples of wild sika deer (Cervus nippon) captured between 2016 and 2019 in 39 of the 47 prefectures of Japan. Five of the 237 wild sika deer (2.1%) carried E. coli with resistance to at least one antimicrobial, and all the resistant isolates showed resistance to tetracycline. The resistant isolates contained antimicrobial resistance genes that were similar to those in E. coli derived from humans and farm animals. Although wild sika deer are not currently likely to be a source for the transmission of antimicrobial resistance in Japan, they can potentially mediate antimicrobial resistance spread by coming into contact with humans, animals, and their surroundings.  相似文献   

19.
牛肉源大肠杆菌的耐药性检测及相关耐药基因分布   总被引：6，自引：3，他引：3  
为了解牛肉源大肠杆菌的耐药性并检测其相关耐药基因分布,本研究选取了117株牛肉源大肠杆菌,经药敏纸片法对11种抗菌药物进行了药敏检测,并根据耐药表型利用普通和(或)多重PCR技术对耐四环素菌中tet(A)、tet(B)和tet(C)基因,耐氨苄西林菌中blaTEM1、blaPSE1和blaOXA1基因,耐链霉素菌中strA-strB、aadA1基因,耐磺胺类药菌中sul1、sul2和sul3基因进行了调查分析。结果显示,117株大肠杆菌对四环素、氨苄西林、链霉素和磺胺异恶唑的耐药率较高,分别为89%、42%、38%和22%。tet(A)基因是所有四环素耐药基因中最为流行的一种基因(55%);在检测的3个β-内酰胺类药物耐药基因中,最流行的为blaTEM1基因(73%);链霉素的耐药性主要由strA-strB基因(38%)编码;sul2基因在耐磺胺异恶唑菌中的检出率最高(77%)。结果表明本次分离的牛肉源大肠杆菌耐药非常严重,进一步肯定了肉牛业生产中抗菌药的使用对大肠杆菌耐药性的产生和发展所发挥的重要作用,提示食品动物养殖应严格控制饲料中抗菌药的滥用。  相似文献   

20.
Escherichia coli play an important ecological role within resistant bacteria populations, and can be used as a bio-indicator of antimicrobial resistance. The aim of the present study was to use this feature of E. coli to investigate the prevalence of antimicrobial resistance and the degree of cross-species transmission of bacteria in pigs and poultry in China. A total of 592 E. coli strains, isolated from pigs and poultry (healthy and diseased animals), were tested for resistance to 22 antimicrobials representing eight antimicrobial drug types.E. coli isolates had high rates of resistance to ampicillin (99.5%), doxycycline (95.6%), tetracycline (93.4%), trimethoprim–sulfamethoxazole (74.3%), amoxicillin (65.1%), streptomycin (54.7%), and chloramphenicol (50.2%). Resistance to cephalosporins, quinolones, and aminoglycosides was also quite prevalent. The majority (81%) of isolates demonstrated multi-antimicrobial resistance, most commonly to 5–6 different antimicrobial types. One isolate was resistant to all 22 antimicrobials. Twenty-two cultures exhibiting multi-antimicrobial resistance were analysed by pulsed-field gel electrophoresis (PFGE) to assess their distribution between farms. Three distinct PFGE types were identified, indicating inter-farm transmission of multi-antimicrobial resistant bacteria. The study confirmed the presence and transmission of multi-antimicrobial-resistant E. coli strains amongst pigs and poultry in China and highlights the urgent need for appropriate monitoring programmes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号