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1.
Prevalence and characterization of Staphylococcus aureus in young goats   总被引：2，自引：0，他引：2  
Thirty-six Staphylococcus aureus isolates recovered from 35 of 204 young goats at slaughter were characterized. All isolates were susceptible to cephalothin, clindamycin, chloramphenicol, gentamicin, kanamycin, and amikacin. All but 2 were susceptible to erythromycin and tetracycline, and 19 and 20 were susceptible to penicillin and ampicillin, respectively. Thirteen isolates were classified as biotype A, 9 isolates were classified as biotype B, 8 isolates were classified as biotype C, and 6 isolates were classified as intermediate between B and C or were not biotypable. Six biotype A isolates were enterotoxigenic; 4 produced enterotoxin B, 1 produced enterotoxin C, and 1 produced enterotoxin D. Two biotype B strains produced enterotoxin B, and all 8 biotype C isolates produced enterotoxin C and the toxic shock syndrome toxin-1.  相似文献   

2.
Eighty-seven Streptococcus suis isolates recovered in 1999-2000 from diseased pigs, all from different farms, were screened for resistance against macrolide and lincosamide antibiotics by the disk diffusion and agar dilution test and a PCR assay, amplifying the ermB gene and the mefA/E gene. Seventy-one percent of the isolates showed constitutive resistance to macrolide and lincosamide antibiotics (MLS(B)-phenotype). All these isolates were positive for the ermB gene in the PCR, but negative for the mefA/E gene. For all strains minimum inhibitory concentrations (MIC) against five other antimicrobial agents were determined. All strains were susceptible to penicillin. Ninety-nine percent of the isolates were susceptible to enrofloxacin and tiamulin. Eighty-five percent of the strains were resistant to doxycycline. A 540bp fragment of the ermB genes of eight S. suis strains was sequenced and compared with ermB genes of five S. pneumoniae and five S. pyogenes strains of human origin. A 100% homology was found between these fragments in seven S. suis, one S. pneumoniae and three of the S. pyogenes isolates. This study demonstrates that resistance against macrolides, lincosamides and streptogramin B is widespread in S. suis and mediated by ribosome methylation, encoded by the ermB gene.  相似文献   

3.
Mycobacteria were isolated and characterised from 49 cats with extensive infections of the subcutis and skin. Cats were generally between 3 and 10 years of age, and female cats were markedly over-represented. All isolates were rapid-growers and identified as either Mycobacteria smegmatis (40 strains) or M fortuitum (nine strains). On the basis of Etest for minimum inhibitory concentration and/or disc diffusion susceptibility testing, all strains of M smegmatis were susceptible to trimethoprim while all strains of M fortuitum were resistant. M smegmatis strains were typically susceptible to doxycycline, gentamicin and fluoroquinolones but not clarithromycin. All M fortuitum strains were susceptible to fluoroquinolones, and often also susceptible to gentamicin, doxycycline and clarithromycin. Generally, M smegmatis strains were more susceptible to antimicrobial agents than M fortuitum strains. Treatment of mycobacterial panniculitis involves long courses of antimicrobial agents, typically of 3-6 months, chosen on the basis of in vitro susceptibility testing and often combined with extensive surgical debridement and wound reconstruction. These therapies will result in effective cure of the disease. One or a combination of doxycycline, ciprofloxacin/enrofloxacin or clarithromycin are the drugs of choice for long-term oral therapy.  相似文献   

4.
The minimal inhibitory concentrations of fifteen antibacterial agents were determined by agar-dilution method against 121 strains of Clostridium perfringens isolated from pigs, cattle and poultry. All strains, regardless of host of origin, were susceptible to avoparcin, furazolidone, monensin, nitrovin, penicillin G, ronidazole and tiamulin and resistant to flavomycin. Poultry strains were also susceptible to carbadox, chloramphenicol, erythromycin and virginiamycin. Bacitracin-resistant poultry strains were susceptible to all tested antibacterial agents except tetracycline, but the bacitracin-resistant cattle strains were polyresistant. Porcine strains were susceptible to bacitracin and bovine strains to carbadox. Carbadox-resistant porcine strains were resistant to erythromycin, lincomycin and tetracycline and susceptible to chloramphenicol. Resistance to erythromycin was associated with resistance to lincomycin. High level erythromycin-lincomycin-resistant strains were susceptible to virginiamycin, but the intermediate level erythromycin-lincomycin-resistant cattle strains were resistant to virginiamycin. Resistance to chloramphenicol or erythromycin-lincomycin was always associated with resistance to tetracycline but the reverse was not always true.  相似文献   

5.
探索苜蓿苔螨(Bryobia praetions)抗阿维菌素品系(R)与敏感品系(S)生物适合度变化,为延缓苜蓿苔螨抗性发展及其抗性治理提供依据。在室内26℃条件下,系统观察了苜蓿苔螨抗阿维菌素品系试验种群的发育和生殖力参数。结果表明,抗阿维菌素品系的发育历期和寿命缩短,产卵量下降。抗性品系(R)平均寿命为21.9 d,平均每雌产卵量为28.2粒;敏感品系分别为27.9 d和40.9粒。抗阿维菌素品系的净生殖率(R0=28.17)显著低于敏感品系(R0=45.70)(P<0.05)。抗阿维菌素品系周限增长率(λ)和种群加倍时间(p.b.t)分别为1.159 2和2.978 8,均显著低于敏感品系的周限增长率和种群加倍时间(P<0.05)。对苜蓿苔螨的抗性品系与敏感品系进行比较,抗性品系存在着生殖力的不利性。另外,抗性品系的相对适合度(Rf)约为敏感品系的0.49,也存在着明显的相对适合度缺陷。本研究结论有助于解释苜蓿苔螨抗阿维菌素品系存在生物适合度不利的现象,并为苜蓿苔螨抗性治理提供参考。  相似文献   

6.
Brucella are resistant to polymyxin B (PB), but their relative susceptibility to PB and its derivative, colistin (COL) has not been rigorously or systematically studied. Comparative susceptibility of Brucella reference strains, vaccine strain RB51, and Brucella isolates from marine mammals to these two cationic peptides were determined by Etest. Vast differences among Brucella species were found in susceptibility to both PB and COL. Brucella demonstrated similar pattern of relative susceptibility to PB as that of COL, but they were less susceptible to COL. Both B. melitensis and B. suis were the least susceptible to polymyxins and rough strains were more susceptible to both PB and COL than the smooth except for the BvrR mutant. Strains were generally less susceptible to PB when cultured in CO(2) rather than ambient air; some became more susceptible in acidified medium. Results show that environment cultural conditions must be considered when selecting for CO(2)-independent strains of Brucella especially the vaccine strain RB51 on selective media containing PB. Our observations extend basic knowledge of the differential resistance of Brucella to polymyxins.  相似文献   

7.
Campylobacter species are among the most frequently identified bacterial causes of human gastroenteritis. Because Campylobacter spp. harbored by cattle can be transmitted to humans, in this study we investigated antimicrobial resistance of thermophilic Campylobacter isolated from cows. Our study included 150 strains of Campylobacter (143 strains of C. jejuni and 7 strains of C. coli) isolated from cows in South-Western Poland. The minimal inhibitory concentration (MIC) to ciprofloxacin, erythromycin, gentamicin and tetracycline were determined using the agar dilution methodology. All strains of C. coli were susceptible to all four drugs studied. The most frequently detected resistance of C. jejuni was to ciprofloxacin (26 strains 18.2%). Resistance to tetracycline was observed in 5 strains (3.5%). All strains of C. jejuni were susceptible to erythromycin and gentamicin.  相似文献   

8.
江西地区鸭疫里氏杆菌的鉴定及药敏试验   总被引：4，自引：0，他引：4  
杨建远  张良慧  过七根  张炳火  何后军 《中国家禽》2006,28(24):110-111,115
从江西部分地区的25份临床疑似鸭疫里氏杆菌(RA)病例中分离到19株RA。生化特性测定结果表明,19个RA菌株的过氧化氢酶、尿素酶均为阳性,除1株发酵葡萄糖、1株发酵麦芽糖外均不发酵各种糖类,5个RA菌株能液化明胶,15个RA菌株氧化酶阳性,不产生H2S,不还原硝酸盐,吲哚试验、MR试验、VP试验均阴性;80%的菌株对头孢曲松、头孢哌酮、头孢唑啉、罗红霉素等高度敏感,而对阿米卡星、庆大霉素、复方新诺明、卡那霉素、青霉素等耐药。  相似文献   

9.
100 strains of Pseudomonas aeruginosa (P.a.) from birds and reptiles were compared by determination of their O-serovars and their resistance to chemotherapeutic agents. A great number of isolates (birds 17.4%, reptiles 29.6%) were serologically untypable using 17 O-antisera by slide-agglutination-technique. The prevalence of O-serovar 0:6 was found in birds (39%) and reptiles (18.5%), followed by bird-isolates 0:1 and 0:3 (each 13%) and reptile-isolates 0:16 (14.8%). The serological distribution was different among bird- and reptile-isolates and also among the human and animal strains. All strains were resistant to penicillin G and ampicillin, more than 90% to nitrofurantoin, sulfamethoxazole-trimethoprim, chloramphenicol and erythromycin. Resistance to tetracycline was found to be 87%, resistance to sulfonamide 81%, respectively. 32% of all isolates were resistant to streptomycin, 61% to kanamycin. All isolates were susceptible to genta- and neomycin. Also all isolates, except one reptile-strain, were susceptible to gyrase-blocker (Bay VP 2674). 2 isolates were resistant to polymyxin B.  相似文献   

10.
Using different typing methods (MLST, spa‐, SCCmec‐ and agr‐typing), PFGE and DNA microarray‐based chip analysis, we characterized 20 MRSA strains isolated from livestock and veterinarians. PFGE analysis after macrorestriction with EagI provided seven different band patterns, which could be grouped into four clusters. One cluster consisted of all MRSA ST398 strains isolated from pigs, calves, mastitis milk and two veterinarians. One strain of ST398 from a veterinarian and the two strains of ST1 and ST8 formed the three other clusters. Antimicrobial susceptibility testing showed that 15 of 20 strains were resistant to ampicillin, cefoxitin, clindamycin, erythromycin, oxacillin, penicillin and tetracycline. All strains were susceptible to rifampin and vancomycin, 19 were susceptible to ciprofloxacin and 18 were susceptible to sulphamethoxazole/trimethoprim. Genes encoding different enterotoxins, leukotoxins and haemolysins were found in certain strains.  相似文献   

11.
Twenty three susceptible crossbred calves were inoculated with five Indian strains of Theileria annulata, collected from natural cases of tropical theileriosis at Ludhiana, Hissar, Jaipur, Uruli-Kanchan and Bangalore. All the strains produced clinical disease with typical symptoms and lesions of acute theileriosis. The strains were considered highly virulent and equally pathogenic.  相似文献   

12.
将两株鸡传染性法氏囊病病毒（IBDV）弱毒株在SPF鸡体内连续传代至第5、第6代时,出现明显的法氏囊萎缩和B：B指数下降,表明IBDV弱毒株在鸡体内连续传代后毒力增强。为进一步阐释哪些基因位点导致了上述毒力的变化,本试验测定了基础弱毒株及其在鸡体内传代后各个代次毒的基因组序列,比对分析后发现VP2蛋白253位氨基酸发生了由H到Q或N的变异,表明VP2蛋白253位氨基酸的替换可能会增强传染性法氏囊病病毒在鸡体内的致病性。  相似文献   

13.
A total of 221 SIG strains were isolated from clinical samples of canine origin submitted to the Diagnostic Laboratory of the Division of Bacteriology and Molecular Biology at the Warsaw University of Life Sciences in Warsaw during the period 2006-2010. The aim of the study was to investigate the frequency of prevalence of methicillin-resistant SIG strains and to determine the MIC values of cephalotin, amoxicillin/clavulanic acid, ciprofloxacin, clindamycin, gentamicin, chloramphenicol, mupirocin for a collection of randomly selected 79 strains belonging to Staphylococcus intermedius group (SIG), including 23 mecA-positive and 56 mecA-negative strains. All isolates were identified as belonging to SIG based on their phenotypic properties and PCR amplification of S. intermedius-specific fragment of the 16S rRNA gene. The mecA gene was detected in 26 (12%) of 221 SIG strains. All tested mecA-negative SIG strains were susceptible to amoxicillin/clavulanic acid and cephalotin. One of the 56 mecA-negative SIG strains was resistant to ciprofloxacin, six (11%) to gentamicin. It was found that sixteen (29%) of 56 mecA-negative SIG strains were resistant to clindamycin. Most of the mecA-positive SIG strains were resistant to ciprofloxacin (96%), clindamycin (96%), and gentamicin (96%). Only one MRSIG strain was resistant to chloramphenicol. All examined mecA-positive SIG strains were found to be susceptible to mupirocin. Our results imply that staphylococcal multidrug resistance has become more prevalent, which could lead to difficulties in effective treatment. With some resistant strains the only therapeutic possibility are antimicrobial agents important in human medicine. New regulations for veterinary medicine concerning appropriate therapy of infections caused by multidrug-resistat staphylococci are needed.  相似文献   

14.
A total of 229 Spanish Actinobacillus pleuropneumoniae isolates recovered from diseased pigs with pleuropneumonia from 1997 to 2004 was tested for their susceptibility to 11 antimicrobials in a broth microdilution method. All the isolates were susceptible to florfenicol and most of them to cephalothin; however, a high rate of resistance was observed to tetracycline. A bimodal or multimodal distribution of isolates over the MIC range were observed for penicillins, tetracycline, trimethoprim, sulfisoxazole and nalidixic acid, suggesting the development of acquired resistance. Eight resistance patterns were established, and 21.1% of the isolates were resistant to at least two antimicrobials. In addition, a considerable increase in the resistance to tetracyclines was observed during the last decade in Spain, when compared with other A. pleuropneumoniae strains isolated during 1987-1988 (Gutiérrez, C.B., Píriz, S., Vadillo, S., Rodríguez Ferri, E.F., 1993. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents. Am. J. Vet. Res. 54, 546-550); this finding was also observed for gentamicin in minor percentage.  相似文献   

15.
Staphylococcus pseudintermedius strains were isolated from healthy dogs and dogs with pyoderma in 2000-2002 and 2009. All the isolates from dogs with pyoderma in 1999-2000 and from healthy dogs in 2000-2002 and 2009 were susceptible to cefalexin and/or other cephalosporins and oxacillin. However, 7.1-12.5 and 11.4% of S. pseudintermedius isolates from dogs with pyoderma in 2009 were resistant to cephalosporins and oxacillin, respectively. All S. pseudintermedius isolates from dogs with pyoderma in 1999-2000 and those from healthy dogs in 2000-2002 were susceptible to fluoroquinolones; however, 50% of the S. pseudintermedius strains isolated from dogs with pyoderma in 2009 and 30% of the S. pseudintermedius strains isolated from healthy dogs in 2009 were resistant to fluoroquinolones. Of the 21 oxacillin-resistant S. pseudintermedius (MRSP) isolates, 11 carried SCCmec type V and 10 carried hybrid SCCmec types II-III. Staphylococcus pseudintermedius strains that were resistant to only one of three fluoroquinolones had a mutation in the quinolone resistance determination region of grlA, whereas S. pseudintermedius strains that were resistant to two or more fluoroquinolones had mutations in the quinolone resistance determination regions of both grlA and gyrA.  相似文献   

16.
Variation in virulence among different strains of Serpulina hyodysenteriae was studied by oral inoculation of specific pathogen free piglets and CD-1 mice. Piglets infected with serotype 2 reference strain B204 and an untypable field strain LHV-90-9-I had severe diarrhea tainted intermittently with mucus and fresh blood. The piglets inoculated with B169, B8044, B6933, and ACK300-8 reference strains representing serotypes 3, 5, 6, and 7 respectively developed moderate diarrhea. However, reference strains B234 and A-1 of serotypes 1 and 4, respectively, failed to cause any diarrhea. None of the S. hyodysenteriae strains caused diarrhea in mice. The results indicate a great variation in virulence among strains of different serotypes of S. hyodysenteriae. Mice were less susceptible to infection with S. hyodysenteriae.  相似文献   

17.
The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimethoprim. All strains were susceptible to erythromycin and rifampicin. The strains isolated from humans showed somewhat higher rate of antibiotic resistance to penicillin, cefotaxime, kanamycin, streptomycin, lincomycin, and oxytetracycline. The overwhelming majority (96%) of the equine isolates belonged to serotype 1 in Prescott's serotyping system, while the human isolates could not be serotyped.  相似文献   

18.
A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).  相似文献   

19.
Anthrax, which is caused by the bacterium Bacillus anthracis, is one of the oldest documented infectious diseases in both livestock and humans. The differentiation of B. anthracis strains is difficult because of their highly homogeneous genomes. We used multiple-locus variable-number tandem repeat analysis (MLVA) with 25 markers to genotype 55 B. anthracis isolates from 16 distinct regions of Turkey. The antimicrobial susceptibility of the isolates was investigated using the agar dilution method. An eight-loci MLVA assay revealed six unique genotypes (G(K)13, G(K)27, G(K)35, G(K)43, G(K)44, and G(K)61). However, the 25-loci MLVA was more discriminatory, revealing the presence of ten genotypes instead of six. The additional genotypes resulted from the split of four subtypes: G(K)35 (b and c), G(K)43 (a and f), G(K)44 (d and e), and G(K)61 (i and j). All of the Turkish B. anthracis isolates were susceptible to ciprofloxacin, levofloxacin, tigecycline, linezolid, and vancomycin. One isolate was resistant to penicillin and to doxycycline. A total of 34 isolates were susceptible, 20 isolates were partially susceptible, and one isolate was resistant to erythromycin. None of the isolates exhibited susceptibility to cefotaxime. A total of 53 isolates were susceptible to gentamicin, and two were resistant. The genotypes G(K)35 (n=24), G(K)44 (n=13), and G(K)43 (n=10) were the most prevalent in 10, 6, and 5 regions, respectively, of the total 16 provinces. The B. anthracis isolates collected from these regions implied that the movement of B. anthracis is a result of the increased transportation of livestock and the resultant cross contamination.  相似文献   

20.
Summary

Twenty three susceptible crossbred calves were inoculated with five Indian strains of Theileria annulata, collected from natural cases of tropical theileriosis at Ludhiana, Hissar, Jaipur, Uruli‐Kanchan and Bangalore. All the strains produced clinical disease with typical symptoms and lesions of acute theileriosis. The strains were considered highly virulent and equally pathogenic.  相似文献   

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