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 31 毫秒
1.
Limited data regarding the susceptibility of Actinobacillus pleuropneumoniae to antimicrobials has been published during recent years. Accordingly, the aim of the present study was to investigate the distribution of MICs for the isolates of A. pleuropneumoniae from diseased pigs in the Czech Republic between 2007 and 2009. A total of 242 isolates were tested for susceptibility to 16 antimicrobial agents by a broth microdilution method. A low degree of resistance was observed for florfenicol (0.8%), amoxicillin and clavulanic acid (0.8%), tilmicosin (1.2%), tiamulin (1.7%) and ampicillin (3.3%), whereas resistance to tetracycline was detected more frequently, 23.9% of isolates. Interestingly, resistance to florfenicol has not yet been reported in any study investigating antimicrobial resistance of A. pleuropneumoniae. By PCR the presence of the floR gene was confirmed in all florfenicol resistant isolates.  相似文献   

2.
The aim of this retrospective study was to evaluate the antimicrobial resistance rates and the trend in resistance of Actinobacillus pleuropneumoniae isolated from pigs in Italy from 1994 to 2009. A total of 992 A. pleuropneumoniae isolates were tested for their susceptibility to a panel of antimicrobial agents in a disk diffusion method. Resistance to 7 drugs (amoxicillin, amoxicillin/clavulanic acid, ampicillin, cefquinome, cotrimoxazole, penicillin G and tilmicosin) showed a significant increasing trend over the time, while for 2 drugs (gentamycin and marbofloxacin) a significant decrease was observed. Resistance to the remaining 14 antimicrobial agents tested did not change significantly over the study period. Most of the isolates retained high susceptibility to antimicrobials usually effective against A. pleuropneumoniae such as amphenicols, fluoroquinolones and ceftiofur. However, high rates of resistance were observed for potentiated sulfa drugs, tetracyclines and penicillins which are currently recommended antimicrobials for pig pleuropneumonia therapy. Our results suggest the importance of continued monitoring of A. pleuropneumoniae clinical isolates in order to choose the most appropriate treatment of infections and to control the increase of resistance to currently used antimicrobials.  相似文献   

3.
A total of 83 Actinobacillus pleuropneumoniae and 58 Actinobacillus porcitonsillarum strains collected from slaughtered pigs in Switzerland were screened for susceptibility to 20 antimicrobial agents by MIC determinations. Resistance to sulfamethoxazole, the combination sulfamethoxazole-trimethoprim, tiamulin, tilmicosin, tetracycline, penicillin and ampicillin were found. A few A. porcitonsillarum isolates displayed decreased susceptibility to enrofloxacin. PCR analysis revealed the presence of the sul2 gene in approximately one-fifth of the sulfonamide-resistant A. pleuropneumoniae and A. porcitonsillarum isolates. The tetracycline-resistant A. pleuropneumoniae harbored tet(B) and tet(H), whereas the tetracycline-resistant A. porcitonsillarum isolates harbored the tet(B) gene. The penicillin and ampicillin-resistant A. pleuropneumoniae and A. porcitonsillarum harbored the bla(ROB-1) gene.  相似文献   

4.
Forty-five isolates of Actinobacillus pleuropneumoniae were tested for susceptibility to 12 antimicrobial agents using a microdilution method for the minimal inhibitory concentration determinations. These results confirmed the high prevalence of A. pleuropneumoniae strains resistant to antibiotics as reported earlier using the disc diffusion method (Kirby-Bauer method). While 36% of the isolates were resistant to the penicillins, 47% were resistant to chloramphenicol and 68% were resistant to tetracycline. Minimal inhibitory concentrations for the resistant isolates were approximately 32 times higher than those for the susceptible isolates to the above antibacterial agents. The isolates were in general weakly susceptible or resistant to spectinomycin, lincomycin, tiamulin and spiramycin whereas most of them were susceptible to gentamicin, trimethoprim and erythromycin. The susceptibility pattern was similar throughout the 1980 to 1984 period. The 14 serotype 5 isolates were more resistant to tetracycline but less resistant to chloramphenicol and the penicillins than the 28 serotype 1 isolates.  相似文献   

5.
Minimum inhibition concentrations (MICs) were determined for ampicillin, ceftiofur, cephalothin, chloramphenicol, enrofloxacin, gentamicin, lincomycin, lincospectin (lincomycin/spectinomycin), neomycin, premafloxacin, spectinomycin, sulfamethoxazole/trimethoprim, and tetracycline against a total of 180 isolates of Actinobacillus pleuropneumoniae, Escherichia coli, and Salmonella choleraesuis (60 each) clinically isolated from pigs on farms in Taiwan from 1994 to 1996. No more than 3 isolates per farm were used. Ceftiofur had the highest activity in vitro against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 0.03, 2, and 1 microg/ml, respectively. Premafloxacin was highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 2, 8, and 0.5 microg/ml, respectively, which were lower than those with enrofloxacin (MIC90 8, 32, and 2 microg/ml, respectively). Neomycin was moderately active against A. pleuropneumoniae and E. coli, with MIC90 values of 8 and 64 microg/ml, respectively, but was inactive with S. choleraesuis. Gentamicin showed high activity against A. pleuropneumoniae (MIC90 of 2 microg/ml) but was only moderately active with E. coli and S. choleraesuis (MIC90 of 64 and 32 microg/ml). Cephalothin was highly active against isolates of A. pleuropneumoniae (MIC90 of 1 microg/ml) but was inactive with E. coli (MIC90 of 128 microg/ml). Lincomycin had moderate activity (MIC90 of 32 microg/ml) against A. pleuropneumoniae. Chloramphenicol, lincomycin, and tetracycline were inactive with E. coli and S. choleraesuis (MIC90 > 128 microg/ml). In conclusion, ceftiofur and premafloxacin were highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, enrofloxacin and gentamicin were highly to moderately active; cephalothin was highly active against A. pleuropneumoniae and moderately active against S. cholearesuis; chloramphenicol, lincomycin, and tetracycline were active only with A. pleuropneumoniae; neomycin was moderately active against A. pleuropneumoniae and E. coli. The other antimicrobials tested were inactive.  相似文献   

6.
A total of 70 haemophili from Australia pigs was compared with a range of reference strains of porcine haemophili. Forty-eight of the isolates were identified as Actinobacillus pleuropneumoniae biovar 1 and the remaining 22 isolates as Haemophilus parasuis. Forty one of the A. pleuropneumoniae isolates were used in a study to determine to the minimal inhibitory concentration (MIC) of 12 antimicrobial agents, or combinations of agents. Penicillin, neomycin, trimethoprim, trimethoprim-sulphamethoxazole and tetracycline all showed low MIC values, indicating their potential for the treatment of porcine pleuropneumonia, although 2 isolates showed resistance to tetracycline. A wide range of MIC values was encountered with the sulphonamides.  相似文献   

7.
Antibiotic susceptibility of bacteria isolated from nasal swabs and lungs of pigs, to 16 commonly used antibiotics, was determined by disc diffusion test. beta-lactams showed the best activity against Streptococcus suis (S. suis) (> 99% of susceptible strains). The lowest sensitivity of S. suis was evidenced to: tylosin, tetracycline and neomycin (50%, 40% and 25%, respectively). Isolates of Escherichia coli (E. coli) demonstrated the highest susceptibility to cephalosporin (85% strains), gentamicin and norfloxacin (over 74%). The lowest susceptibility of E. coli was demonstrated to tiamulin and penicillin (11.3% and 1.9%, respectively). Over 80% of Actinobacillus pleuropneumoniae (App) strains were susceptible to all antibiotics tested. The highest resistance of App, but demonstrated by below 20% of tested isolates only, was evidenced to neomycin and LxS. Isolates of Pasteurella multocida (Pm), Haemophilus parasuis (Hps) and Arcanobacterium pyogenes (A. pyogenes) were highly susceptible to the most antibiotics included in the analysis. The comparison of the in vitro susceptibility of pathogens to the chemotherapeutics used on Polish farms for the therapy of bacterial infection of pigs within the last five years and the last 10 years, showed an increasing percent of E. coli and S. suis strains resistant to commonly used antibiotics. It is also shown that Pm, Hps, App and A. pyogenes isolates were continuously susceptible to the most chemotherapeutics applied.  相似文献   

8.
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   

9.
This study was conducted to compare the applicability of three different media in sensitivity testing of Actinobacillus pleuropneumoniae by means of MIC and tablet diffusion tests. The media used were: modified PPLO agar, chocolatized Mueller-Hinton-II and Columbia agar supplemented with NAD. Seven antimicrobial agents were tested: ceftiofur, enrofloxacin, penicillin, spectinomycin, tiamulin, trimethoprim + sulfadiazine and tylosin, against 40 randomly selected A. pleuropneumoniae isolates. In general, good agreement was found between results obtained with all combinations of media, most antimicrobials tested and the two-test systems. Some variations between media were observed for spectinomycin, tiamulin and tylosin. For ceftiofur and trimethoprim + sulfadiazine some isolates with low MIC-values were classified as resistant using tablet diffusion, indicating that the break points of resistance for these antimicrobials using the tablet diffusion tests need adjustment. Using current break points for resistance with MIC-determinations, all isolates tested susceptible to ceftiofur, enrofloxacin, penicillin, tiamulin and trimethoprim + sulfadiazine. A larger number of isolates tested resistant to spectinomycin and tylosin on all three media using both MIC determinations and tablet diffusion.  相似文献   

10.
"Actinobacillus porcitonsillarum" is a newly suggested commensal species colonizing porcine tonsils. In the diagnostic laboratory the sole difference to the porcine lung pathogen Actinobacillus pleuropneumoniae is a negative mannitol reaction. In order to substantiate and improve this important differentiation a PCR test was developed using the relevant reference strains including Actinobacillus minor. The practicability of the test was confirmed on 20 clinical isolates of Actinobacillus spp. cultured from 100 tonsil samples originating from 18 farms in Thailand. Applying the newly developed PCR test 10 isolates were identified as A. pleuropneumoniae, and 10 as "A. porcitonsillarum" with one of them being mannitol-positive in biochemical testing. Subsequent 16S rRNA sequencing confirmed classification of all 10 strains as "A. porcitonsillarum"/A. minor. These results emphasize that suspected A. pleuropneumoniae isolates, particularly from porcine tonsils, should be confirmed by PCR in order to prevent false positive diagnoses.  相似文献   

11.

Background

The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II) was funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003–05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility of pathogenic and indicator bacteria from food animals using validated and harmonised methodologies. In this report the first data on the occurrence of antimicrobial resistance among bacteria causing infections in pigs are reported.

Methods

Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were collected from fifteen European countries in 2002–2004.

Results

Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low frequency of resistance to tetracycline and trimethoprim – sulphonamide.Data for S. suis were obtained from six countries. In general, a high level of resistance to tetracycline (48.0 – 92.0%) and erythromycin (29.1 – 75.0%) was observed in all countries whereas the level of resistance to ciprofloxacin and penicillin differed between the reporting countries. Isolates from England (and Wales), France and The Netherlands were all susceptible to penicillin. In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004) and to penicillin from 8.1 – 13.0% (2004) in Poland and Portugal.Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas in healthy pigs the frequency of resistance was lower.

Conclusion

Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to several antimicrobial agents in different countries. The occurrence of resistance varied distinctly between isolates from healthy and diseased pigs, with the isolates from healthy pigs generally showing a lower level of resistance than those from diseased pigs.The study suggests that the choice of antimicrobials used for the treatment of diseased animals should preferably be based on knowledge of the local pattern of resistance.  相似文献   

12.
2014-2016年从广州市屠宰场分离沙门氏菌151株,鉴定出12种血清型,前3位优势血清型分别为德尔卑沙门氏菌、罗森氏沙门氏菌、鼠伤寒沙门氏菌。采用微量肉汤稀释法测定分离菌株对13种抗菌药物的敏感性。结果显示,沙门氏菌对四环素、多西环素、磺胺异恶唑、氨苄西林、大观霉素的耐药率都在60%以上,对奥格门丁、恩诺沙星、氧氟沙星、头孢噻呋、多粘菌素E敏感（耐药率≤16%）。多重耐药率为79.20%。研究表明,沙门氏菌对部分药物耐药性较严重,亟需加强养殖业抗菌药物的合理应用以控制耐药性的发展。  相似文献   

13.
A survey to estimate the prevalence of antimicrobial resistance in Escherichia coli was conducted in 7 Canadian federally inspected processing plants during 2001. Escherichia coli isolates were recovered during routine hazard analysis critical control point sampling from beef carcasses and trim and subsequently tested for their antimicrobial susceptibility by using susceptibility panels. Of the 2653 isolates analyzed, 68% were sensitive to all 18 antimicrobials tested. For 14 of the 18 antimicrobials evaluated, the percentage of resistant isolates was < or = 1. Twenty-five percent of the isolates were resistant to tetracycline, 9% to sulfamethoxazole, 7% to streptomycin, and 3% to ampicillin. Multiple resistance was found in 12% of the isolates, with 7% showing resistance to 2 antimicrobials, 2% to 3 antimicrobials, 2% to 4 antimicrobials, and 1% to 5 or more antimicrobials. Forty-five different antimicrobial resistance patterns were observed. The reasons for the development of the antimicrobial resistance were not investigated in this study. This study was useful as a pilot to help to develop a national antimicrobial resistance surveillance program in Canada. This study indicates that laboratory standardization is possible for consistent results across the country and that the indicator organism, E. coli, is fairly easy to obtain for surveillance but Salmonella are not, due to their low prevalence in beef.  相似文献   

14.
This study was conducted to determine the MIC values of historical and contemporary Streptoccocus suis (serotypes 2 and 7) from Denmark and S. suis (serotype 2) from Sweden. A total of 52 isolates originating from 1967 through 1981 and 156 isolates from 1992 through 1997 in Denmark and 13 isolates from Sweden were examined for their MICs against 20 different antimicrobial agents. Most antimicrobials were active against most isolates. A frequent occurrence of resistance to sulphamethoxazole was observed, with most resistance among historic isolates of serotype 7 and least resistance among isolates from Sweden. A large number of the isolates was resistant to macrolides. However, all historic serotype 2 isolates from Denmark were susceptible, whereas 20.4% of the contemporary isolates were resistant. Among serotype 7 isolates 23.3% of the historic isolates were resistant to macrolides, whereas resistance was found in 44.8% of the contemporary isolates. All isolates from Sweden were susceptible to macrolides. Time-associated frequency of resistance to tetracycline was also found. Only a single historic isolate of serotype 2 was resistant to tetracycline, whereas 43.9% of the contemporary serotype 2 isolates and 15.5% of the contemporary serotype 7 isolates were resistant. Only one (7.7%) of the isolates from Sweden was resistant. The differences in resistance between historic and contemporary isolates from Denmark were statistically significant. This study demonstrated a significant serotype-associated difference in the susceptibility to macrolides and tetracycline and demonstrated that an increase in resistance among S. suis isolates has taken place during the last 15 years to the two most commonly used antimicrobial agents (tylosin and tetracycline) in pig production in Denmark.  相似文献   

15.
Two unusual Actinobacillus isolates were recovered from pigs with no clinical signs, no lesions and no history of swine pleuropneumonia. Two representative strains (9953L55 and 0347) analyzed in this study were initially biochemically and antigenically identified as A. pleuropneumoniae serotypes 1 and 9, respectively, by traditional identification methods. Both strains presented, however, negative results with three A. pleuropneumoniae-specific PCR tests and revealed in particular the absence of the apxIV toxin genes. However, both strains produced and secreted ApxII toxin although they only harbored the toxin genes apxIICA, which is an uncommon feature for any of the known A. pleuropneumoniae serotypes. Upon experimental inoculation of pigs, these strains proved to be totally non-pathogenic. Animals infected with one of the strains produced antibodies that cross-react with A. pleuropneumoniae serotypes 1-9-11-specific LC-LPS ELISA. Phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that these strains form a separate phylogenetic group that is distinct from other Actinobacillus species and is particularly different from A. pleuropneumoniae.  相似文献   

16.
We isolated 56 Haemophilus (Actinobacillus) pleuropneumoniae strains from the pneumonic porcine lung tissues and tested them for antimicrobial susceptibility. Two drug-resistant strains were obtained. One, named KH-265, was resistant to streptomycin (SM) and sulfonamide (SA), and the other, named KH-195, was resistant to tetracycline (TC). The minimum inhibitory concentrations (MICs) of drugs for resistant strains were 100 micrograms/mliters for SM, 3200 micrograms/mliters for SA, and 12.5 micrograms/mliters for TC. KH-265 possessed a 8.3Kb nonconjugative plasmid, pMS260, encoding SM and SA resistance, which was transformable to E. coli strains. pMS260 belonged to none of 14 incompatibility groups including Inc. P and Inc. Q, so far tested. It was mobilizable to various causative strains for respiratory infections, Pseudomonas aeruginosa, Bordetella bronchiseptica, Pasteurella multocida and Haemophilus pleuropneumoniae, by RP4 (Inc. P) plasmid.  相似文献   

17.
目的建立可以同时检测猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速而可靠的PCR检测方法。方法和结果根据胸膜肺炎放线杆菌的Apx-VIA基因序列、多杀性巴氏杆菌和副猪嗜血杆菌的16SrRNA基因序列设计5条引物。猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌模板的PCR扩增产物大小分别为342bp,485bp和1258bp。复合PCR对1～12型猪胸膜肺炎放线杆菌标准株,6株多杀性巴氏杆菌标准株,1～15型副猪嗜血杆菌以及25株经生化鉴定确认为上述三种细菌的分离株的基因组DNA作为模板进行检测,均获得预期大小的扩增产物。以猪放线杆菌、吲哚放线杆菌等14种常见细菌作为阴性对照进行PCR检测,结果仅有支气管败血波氏杆菌产生了可以和上述三个特异性条带明显区分的PCR产物。复合PCR针对胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的敏感性分别为14pg、34pg和37pg。结论本研究建立的复合PCR特异性好,敏感性高,可以用于猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速检测。  相似文献   

18.
四环素类药物是在兽医临床中常用的一类抗生素,为了解胸膜肺炎放线杆菌(Actinobacillus pleuropneumoniae,APP)对四环素类抗生素的耐药情况,本研究对从临床分离鉴定的85株APP进行了四环素类抗生素临床耐药情况和相关基因的分析和检测。应用药敏纸片法进行药敏试验,结果:APP对四环素的耐药率较高为76.5%,其次为金霉素54.1%、美他环素48.2%、多西环素45.9%、土霉素28.2%、米诺霉素25.9%、替加环素22.3%。采用PCR方法对四环素类10种耐药基因tetA、tetB、tetC、tetD、tetE、tetG、tetH、tet1、tetL1和tetL2进行检测,结果:tetA、tetB、tetC、tetD、tetE、tetG、tetH、tet1、tetL2、tetL1耐药基因的扩增阳性率分别为78.8%、41.2%、15.3%、8.2%、21.2%、15.3%、43.5%、24.7%和30.6%,而tetL1扩增则全部阴性,未检出其耐药基因。本研究结果为四环素类抗生素在猪传染性胸膜肺炎临床上的应用和新药研发提供了一定的理论依据。  相似文献   

19.
A restriction analysis of PCR (PCR-REA) amplified apxIVA gene has been suggested as an alternative method for serotyping of Actinobacillus pleuropneumoniae by Jaglic et al. [Jaglic, Z., Svastova, P., Rychlik, I., Nedbalcova, K., Kucerova, Z., Pavlik, I., Bartos, M., 2004. Differentiation of Actinobacillus pleuropneumoniae by PCR-REA based on sequence variability of the apxIVA gene and by ribotyping. Vet. Microbiol. 103, 63-69]. The current study investigated whether this alternative method could distinguish between the reference strains of serovars 13-15 and the value of the method when applied to 47 field isolates representing serovars 1-3, 5, 7-9, 12 and 15 as well as non-typable isolates. The reference strains of serovars 13 and 14 had the same sized product after the apxIVA PCR, while the product for serovar 15 was of different size compared to all the other serovar reference strains. The CfoI digest profiles of the reference serovars 13 and 14 strains were different from each other and from all other serovars. The HpaII digest profiles of these two serovars were very similar to each other, but both were distinctively different from the other serovar profiles. The CfoI digest profile of serovar 15 strain was very similar to the serovars 3 and 12 strains except for two faint extra bands for serovar 15. The HpaII digest profiles of serovars 12 and 15 reference strains were identical. The PCR-REA method correctly recognized the serovar of 21 of 43 field isolates. It was concluded that the method was a useful additional tool to support, but could not replace, conventional serotyping.  相似文献   

20.
OBJECTIVE: To evaluate the antimicrobial susceptibility patterns of Salmonella isolates from feedlot cattle. DESIGN: Cross-sectional study. SAMPLE POPULATION: 263 Salmonella isolates. PROCEDURES: Fecal samples were collected from the floor of 2 pens in each of 100 feedlots. Two hundred eighty Salmonella isolates were recovered after bacteriologic culture from 38 pens. Of these, 263 isolates were available for antimicrobial susceptibility testing to 16 antimicrobials, using microbroth dilution breakpoint plates. RESULTS: Less than 5% of isolates were resistant to any of the antimicrobials tested, with the exception of sulfamethoxazole (15; 5.7%) and tetracycline (61; 23.2%). Most isolates (197; 74.9%) were susceptible to all antimicrobials tested, whereas 18 (6.8%) were resistant to 2 or more antimicrobials. The percentage of isolates with resistance to any antimicrobial varied by serotype. The percentage of isolates resistant to various antimicrobials was not related to concurrent use of antimicrobials in the feed. CONCLUSIONS AND CLINICAL RELEVANCE: With the exception of tetracycline and sulfamethoxazole, resistance of Salmonella isolates to any of the antimicrobials was uncommon. Most isolates were susceptible to all antimicrobials tested. Antimicrobial resistance was not related to the presence of antimicrobials in the ration being fed at the time of sample collection.  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