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1.
The in vitro susceptibilities of 50 field isolates of Riemerella anatipestifer from ducks to ceftiofur and 16 other commonly used antimicrobials were determined. The MIC90 values (MIC refers to minimum inhibitory concentrations) for the antimicrobials used in this study are as follows: penicillin was 16 microg/ml; ceftiofur was 32 microg/ml; cephalothin, chloramphenicol, flumequine, and kanamycin were 64 microg/ml; nalidixic acid, nitrofurantoin, and sulfamethoxazole were 128 microg/ml; amikacin, ampicillin, gentamicin, lincomycin, spectinomycin, streptomycin, tetracycline, and trimethoprim were > or = 256 microg/ml. The therapeutic efficacy of ceftiofur against a highly lethal experimental R. anatipestifer infection in ducks was also evaluated. All experimental ducks were infected through the infraorbital sinus with 1 ml of 9 x 10(9) CFU of R. anatipestifer. Ceftiofur (0, 0.25, 0.5, 1, and 2 mg/kg) was injected subcutaneously 5 hours after infection. A single dose of 2 mg/kg resulted in 73% survival as compared with 10% survival in the infected, but untreated controls.  相似文献   

2.
This study was undertaken to determine the antimicrobial resistance patterns of Salmonella enterica subspecies enterica recovered from human, food, water, and animal samples collected in Khartoum State, Sudan. A total of 64 Salmonella isolates belonging to 28 different serovars were tested for their susceptibility to 13 antimicrobial agents. The majority of isolates (98.4 %) were resistant to at least one antimicrobial agent. Isolates were frequently resistant to ampicillin (90.6 %), cephalexin (50.0 %), nalidixic acid (25.0 %), streptomycin (21.9 %), kanamycin (18.8 %), gentamicin (17.2 %), and co-trimoxazole and trimethoprim (12.5 %). The most common pattern of multiple drug resistance included resistance to ampicillin and cephalexin. Most isolates were sensitive to chloramphenicol (98.4 %), ciprofloxacin (93.8 %), and norfloxacin (90.6 %). Two chicken- and the two human-origin S. Kentucky isolates were resistant to both ciprofloxacin and norfloxacin. All S. Kentucky isolates and the one S. Rissen isolate demonstrated multi-drug resistance. The results indicate the significance of multi-drug-resistant Salmonella serovars isolated from chickens and other animals and foods as sources for multi-drug-resistant Salmonella in humans in Sudan.  相似文献   

3.
M Y Lin 《Avian diseases》1987,31(4):705-712
Twenty-nine antibiotics or drugs were incorporated individually into mycoplasma agar to evaluate their inhibitory activity against avian mycoplasmas: 100 recent Taiwan isolates of 7 serotypes and 10 standard strains of 7 serotypes were tested. All of the standard strains were very sensitive to erythromycin, chlorotetracycline, doxycycline, minocycline, and tetracycline, but the local isolates were highly resistant to these antibiotics. The drugs or antibiotics that possessed an MIC90 of 50 micrograms/ml or less against the local isolates were tiamulin (less than 0.4 micrograms/ml), lincospectin (2.7), josamycin (2.7), lincomycin (3.0), spectinomycin (4.8), tylosin (6.0), kanamycin (6.0), chloramphenicol (6.0), gentamicin (7.5), apramycin (24.5), doxycycline (27.4), minocycline (29.0), spiramycin (30.0), colistin (44.3), leucomycin (45.0), and streptomycin (50.0). The MIC90 of the other antibiotics or drugs was greater than 50 micrograms/ml. None of the isolates or strains were sensitive to nalidixic acid, ronidazole, penicillin, ampicillin, cephalexin, carbadox, or four sulfa drugs at a concentration about 5 times the therapeutic level.  相似文献   

4.
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   

5.
Minimal concentrations of penicillin, ampicillin, cephalothin, chloramphenicol, tetracycline, erythromycin, nitrofurantoin, kanamycin and gentamicin inhibitory to Pasteurella haemolytica biotypes A and T were determined. They were found to be significantly higher for T than for A type strains in the case of all the antimicrobial drugs tested except the two aminoglycosides kanamycin and gentamicin, for which no differences were observed. In the case of penicillin the differences were so marked that they may be useful as a basis for biotyping P haemolytica isolates. The emergence of antibiotic-resistant strains observed in recent years, however, may limit such application.  相似文献   

6.
The objective of this study was to determine the prevalence of antimicrobial resistance among Salmonella isolated from dairy herds in New York, Minnesota, Michigan, and Wisconsin, USA. Serogroup and antimicrobial susceptibility characteristics were determined for Salmonella from cattle and environmental samples collected during August 2000–October 2001 as part of a longitudinal study where 129 herds were visited at 2-month intervals. Salmonella isolates were tested (using a broth microdilution method) for susceptibility to amoxicillin/clavulanic acid, ampicillin, ceftiofur, ceftriaxone, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim/sulfamethoxazole. Of the 1506 isolates tested for minimum inhibitory concentrations to these 14 antimicrobial agents, 81.2% were pan-susceptible and for most herds (81.6%) the predominant antimicrobial resistance pattern was pan-susceptible. At least 1 Salmonella isolate resistant to 5 or more antimicrobial agents was found on 23.6% of herds. This resistance phenotype was most common among serogroups B and E1 and among samples from calves and farmer-designated sick cows. Resistant samples most frequently exhibited resistance to tetracycline, streptomycin, and/or ampicillin. No samples were resistant to ceftriaxone (though 13 were in the intermediate range), and very few samples were resistant to ciprofloxacin (n = 1), nalidixic acid (n = 5), or trimethoprim/sulfamethoxazole (n = 7).  相似文献   

7.
Over a 2 1/2-year period (January 1981 to June 1983), 177 Escherichia coli isolates were obtained from 145 field-reared broiler flocks in the Delmarva peninsula, and 20 were obtained from clinically normal day-old hatchery chickens representing an additional 17 flocks in Delmarva. Ninety-one isolates obtained from the field-reared birds between 2 and 8 weeks of age were associated with complicated air-sac disease. Serotyping efforts demonstrated a predominance of O2, O35, and O78 serogroups and a large number of untypable isolates. More than 50% of the isolates in each of the three dominant serogroups were collected from broilers with colibacillosis, but they were never detected in the yolk-sac samples of clinically normal day-old hatchery chickens. In vitro biochemical characterization of the E. coli isolates revealed variable rates of carbohydrate fermentation and amino acid decarboxylation. No common characteristics appeared to be shared by the predominant serogroups isolated from clinically affected birds, although several serogroup-specific reactions were noted. The majority of the isolates were sensitive to chloramphenicol, gentamicin, nalidixic acid, ormethoprim-sulfadimethoxine, spectinomycin, neomycin, and ampicillin. About half of the isolates were sensitive to nitrofurantoin and the sulfa compounds. Less than 25% of the isolates were sensitive to streptomycin, erythromycin, tetracyclines, novobiocin, penicillin, bacitracin, and lincomycin.  相似文献   

8.
The prevalence and antimicrobial sensitivity of Salmonella spp. in stray dogs in Bursa province, Turkey were determined from a total of 82 faecal samples by bacteriological methods. Of the dogs, nine (11%) were positive for salmonellae-carrying. All Salmonella isolates were serotyped as S. Corvallis, and were sensitive to amoxycillin/clavulanic acid, ampicillin, cephalothin, chloramphenicol, enrofloxacin, gentamicin, kanamycin, nalidixic acid, neomycin, oxytetracycline and trimethoprim/sulphamethoxazole, while 66.7% of them were resistant to streptomycin. It was concluded that stray dogs could be an important carrier of salmonellae as well as a source of human salmonellosis in Turkey. Additional studies are needed to clarify the epidemiological relationship between S. Corvallis isolated from dogs and humans with regard to public health. This is the first report on the isolation of S. Corvallis from dogs in the country.  相似文献   

9.
Staphylococcus intermedius isolates (n=106), including 44 dog isolates and 62 pigeon isolates, were examined for their susceptibility to ampicillin, cephalexin, erythromycin, gentamicin, kanamycin, lincomycin, norfloxacin, oxacillin, tetracycline, and vancomycin by standard disk-diffusion test. The frequencies of resistance to ampicillin, kanamycin, and tetracycline were significantly higher in dog isolates than pigeon isolates (95.5% vs. 0%, 31.8% vs. 0%, and 45.5% vs. 9.7%, respectively; P<0.01). Antimicrobial resistance patterns of dog isolates and pigeon isolates were categorized respectively into nine and five distinct profiles. Significantly higher occurrence of resistance to two or more antimicrobials was observed in dog isolates than pigeon isolates (54.5% vs. 12.9%; P<0.01) and also in domesticated pigeon isolates than non-domesticated pigeon isolates (53.3% vs. 0%; P<0.01).  相似文献   

10.
Ninety-nine isolates of obligate anaerobic bacteria obtained from clinical material were tested for susceptibility to ten antimicrobial agents. Regardless of the species of animal from which the isolates were obtained 90–95% were inhibited by ≤4 μg of ampicillin/ml, ≤4 μg of chloramphenicol/ml, ≤1 μg clindamycin/ml, ≤2 μg metronidazole/ml, ≤8 μg minocycline/ml, ≤16 μg penicillin Gyml, and ≤16 μg tetracycline/ml. All the aminoglycoside antibiotics tested (gentamicin, kanamycin, neomycin, and streptomycin) were shown to be relatively ineffective requiring ≥128 μg/ml for the inhibition of >50%of the isolates. The minimal inhibitory concentration of penicillin G and tetracycline tended to be higher for isolates from non-human primates (penicillin G) and ruminants (tetracycline).  相似文献   

11.
In vitro antimicrobial sensitivity of 12 Hungarian isolates and the type strain ATCC 33144 of Actinobaculum suis to different antimicrobial compounds was determined both by the agar dilution and by the disc diffusion method. By agar dilution, MIC50 values in the range of 0.05-3.125 micrograms/ml were determined for penicillin, ampicillin, ceftiofur, doxycycline, tylosin, pleuromutilins, chloramphenicol, florfenicol, enrofloxacin and lincomycin. The MIC50 value of oxytetracycline and spectinomycin was 6.25 and 12.5 micrograms/ml, respectively. For ofloxacin, flumequine, neomycin, streptomycin, gentamicin, nalidixic acid, nitrofurantoin and sulphamethoxazole + trimethoprim MIC50 values were in the range of 25-100 micrograms/ml. With the disc diffusion method, all strains were sensitive to penicillin, cephalosporins examined, chloramphenicol and florfenicol, tetracyclines examined, pleuromutilins, lincomycin and tylosin. Variable sensitivity was observed for fluoroquinolones (flumequine, enrofloxacin, ofloxacin), most of the strains were susceptible to marbofloxacin. Almost all strains were resistant to aminoglycosides but most of them were sensitive to spectinomycin. A strong correlation was determined for disc diffusion and MIC results (Spearman's rho 0.789, p < 0001). MIC values of the type strain and MIC50 values of other tested strains did not differ significantly. Few strains showed a partially distinct resistance pattern for erythromycin, lincomycin and ampicillin in both methods.  相似文献   

12.
The antimicrobial susceptibility of 201 Listeria monocytogenes isolates from foods, environments, animals and human patients in Japan was determined. All isolates were susceptible to ampicillin, the first choice of drug for listeriosis treatment, chloramphenicol, dihydrostreptomycin, erythromycin, enrofloxacin, gentamicin, kanamycin, lincomycin, nosiheptide, salinomycin, vancomycin, and virginiamycin. A human strain was resistant to oxytetracycline. The Minimum Inhibitory Concentration (MIC) for 50% of the strains and the MIC for 90% of the strains were comparable in all the isolates. This is the first investigation to compare antibiotic resistances between isolates from foods and isolates from human patients in Japan. The result showed that most of the isolates were susceptible to antibiotics used in this study.  相似文献   

13.
2017年1月,在昆明滇池越冬的红嘴鸥排黄色、白色水样稀便,本研究无菌采集红嘴鸥粪便在实验室进行细菌分离培养、染色镜检、提取分离到的菌株核酸进行鉴定、生化鉴定,从10份腹泻红嘴鸥粪便中共分离到70株细菌,根据菌落形态可分为6类细菌,分别从每一类细菌中挑出1株代表性菌株进行鉴定,结果鉴定出这6株细菌分别为大肠杆菌埃希菌、金黄色葡萄球菌、屎肠球菌、志贺氏菌、粘质沙雷氏菌、产酸克雷伯菌。选取氨苄西林、头孢氨苄、头孢拉啶、庆大霉素、卡那霉素、阿米卡星、四环素、氯霉素、环丙沙星、恩诺沙星、磺胺异恶唑、头孢曲松钠药敏纸片,对分离菌株进行耐药性分析,发现细菌对各种抗生素成不同程度敏感性。野鸟携带的条件致病菌,可能会对野生动物健康造成威胁,本研究对腹泻红嘴鸥粪便中携带的条件致病菌及其耐药性进行研究,以期为野鸟携带的细菌的耐药机制提供研究理论依据,同时对野生动物疫病的监测与防控提供指导。  相似文献   

14.
Flumequine (1 g/l) was administered to healthy young chickens in the drinking water for 5 days. A transient increase in the incidence of resistance to flumequine (4 micrograms/ml) was recorded in faecal coliform isolates after administration. Cross-resistance with nalidixic acid was demonstrated, but there was no evidence of cross-resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, sulphadiazide, tetracycline and trimethoprim.  相似文献   

15.
A total of 35 Escherichia coli isolates obtained from necropsy materials of hens with septicemia in the Konya region of Turkey were examined for hemagglutination (HA), cell-surface hydrophobicity, enterotoxigenicity, and drug resistance. HA tests were performed on live cultures with human (group A), bovine, avian (chicken), and guinea pig erythrocytes with and without mannose. Nine HA patterns were observed. Of the 35 isolates, 62.8% exhibited mannose sensitive hemagglutination (MSHA), 8.6% exhibited mannose resistant hemagglutination (MRHA), and 28.6% did not hemagglutinate. Of the isolates, 85.7% were hydrophobic by a salt aggregation test (SAT). Only three isolates were enterotoxigenic by a suckling mouse assay. The majority of the isolates were resistant to chloramphenicol, tetracycline, streptomycin, ampicillin, erythromycin, and trimethoprim + sulfamethoxazole but were highly sensitive to gentamicin and nalidixic acid.  相似文献   

16.
Pseudomonas mallei was isolated from pus samples obtained from 34 mallein-positive horses. The isolates were subjected to in vitro sensitivity test using 16 different antimicrobial discs. All isolates (34) were sensitive to sulfamethizole, gentamycin, tetracycline, sulfathiazole, kanamycin, tobramycin, streptomycin and a combination of trimethoprim and sulfamethoxazole while none of them were sensitive to cephalothin, colistin, ampicillin, penicillin and nitrofurantoin. Rifapicin, chloramphenicol and carbenicillin were effective against 32, 26 and 18 isolates respectively. The minimum inhibitory concentrations (MICs) of gentamycin, tetracycline, tobramycin, sulfamethizole, streptomycin, rifampicin and a combination of trimethoprim and sulfamethoxazole were 0.28, 0.38, 0.67, 1.40, 3.40, 5.86 and 5.30 micrograms/ml, respectively.  相似文献   

17.
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   

18.
Forty-four isolates of Bacillus anthracis made from carcasses and soil in different localities of an endemic anthrax area in the Kruger National Park, South Africa, were tested by standard disc diffusion for their susceptibility to 18 different antibiotics. These were ampicillin, penicillin G, sulphatriad, streptomycin, clindamycin, gentamicin, fusidic acid, trimethoprim, sulphamethoxazole, chloramphenicol, erythromycin, methicillin, tetracycline (2 different concentrations), novobiocin, cefotaxime, netilmicin, cefamandole and cefoxitin. All the isolates were susceptible to ampicillin, streptomycin, chloramphenicol, erythromycin, tetracycline, methicillin and netilmicin. More than 90% of the isolates were sensitive to clindamycin, gentamicin and cefoxitin, whereas only 84.1% of the isolates were sensitive to penicillin G, 86.4% to novobiocin and 68.18% to cefamandole. Complete resistance in 100% of the isolates was encountered with trimethoprim and sulphamethoxazole, with 95.45% for sulphatriad. Moderate sensitivity occurred with penicillin G (15.9% of the isolates), clindamycin (6.8%), novobiocin (13.6%), fusidic acid (84.1%), cefotaxime (100%), cefamandole (31.8%) and cefoxitin (6.8%). The relevance of the findings to the therapeutic uses of different types of antibiotic in human clinical cases referred to in the literature is discussed.  相似文献   

19.
Litter was collected from four turkey farms (eight houses) with a history of fluoroquinolone (FQ) treatment failure, 10 adult broiler breeder chicken farms (43 houses) with one having a history of FQ treatment, and 30 broiler chicken farms (110 houses) with 24 having a history of FQ treatment. In the turkey litter, the percentage of nalidixic acid-resistant (at 100 microg/ml) coliforms/total number of coliforms ranged from 0.6% to 61.9%. Two of the four farms had houses containing coliforms resistant to the two FQs, enrofloxacin (1 microg/ml) and sarafloxacin (1 microg/ml). There was also multiple resistance to other antimicrobials on all four turkey farms (ampicillin, tetracycline, chloramphenicol, kanamycin). The level of total coliforms from the adult broiler breeder litter was low, and there were no nalidixic acid-resistant isolates from any of the 10 farms. In the broiler chickens, 7 of 91 houses with a history of FQ usage contained coliforms resistant to nalidixic acid; however, 2 of the 19 houses on farms with no history of FQ usage had nalidixic acid-resistant coliforms. All of the broiler farms with nalidixic acid-resistant isolates were also resistant to the FQ sarafloxacin, whereas only 3 of the 24 treatment history farms and 1 of the no-treatment history farms exhibited enrofloxacin-resistant coliforms in the litter.  相似文献   

20.
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   

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