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1.
The determination of minimum inhibitory concentrations by broth microdilution is recommended as method of choice for susceptibility testing of veterinary bacterial pathogens. Accordingly, broth microdilution is used in veterinary routine diagnostic laboratories at a progressive rate. To reduce the costs of susceptibility testing, it is reasonable to develop widely accepted uniform microtitre plate layouts that are produced in large quantities. Such microtitre plate layouts have already been developed and published for the susceptibility testing of pathogens from food-producing animals. However, a microtitre plate layout, especially designed for the testing of bacteria from dogs and cats, should be available, too. The choice of the antimicrobial agents or combinations of antimicrobial agents to be included in a suitable layout should be based on the following criteria: (1) the approval and availability of an antimicrobial agent or combination of agents, (2) known cross-resistances, and (3) availability of approved clinical breakpoints. The latter point is of particular importance for the choice of the numbers of concentrations per antimicrobial agent tested and the range of test concentrations. Taking into account these aspects, a science-based layout proposal for microtitre plates, which are suitable for routine testing of bacteria from dogs and cats, is presented and discussed.  相似文献   

2.
Besides their role as commensals on the skin and mucosal surfaces, staphylococci may be involved in a wide variety of diseases in animals. Staphylococcal infections in animals are mainly treated with antimicrobial agents and as a consequence, staphylococci from animal sources have developed and/or acquired resistance to the respective antimicrobial agents. Resistance statistics obtained from national monitoring programmes on staphylococci from cattle and pigs, but also from surveillance studies on staphylococci involved in diseases in dogs are reported and reviewed with regard to their comparability. This review mainly focusses on the genetic basis of antimicrobial resistance in staphylococci of animal origin. Particular attention is paid to resistance to those antimicrobial agents which are most frequently used in veterinary medicine, but also to antimicrobial agents, such as chloramphenicol and mupirocin, which are used in specific cases for the control of staphylococcal infections in pets and companion animals. In addition, plasmids and transposons associated with the respective resistance properties and their ways of spreading between members of the same or different staphylococcal species, but also between staphylococci and other gram-positive bacteria, are described.  相似文献   

3.
Large amounts of antimicrobial agents are in the production of food animals used for therapy and prophylactics of bacterial infections and in feed to promote growth. The use of antimicrobial agents causes problems in the therapy of infections through the selection for resistance among bacteria pathogenic for animals or humans. Current knowledge regarding the occurrence of antimicrobial resistance in food animals, the quantitative impact of the use of different antimicrobial agents on selection for resistance and the most appropriate treatment regimes to limit the development of resistance is incomplete. Programmes monitoring the occurrence and development of resistance are essential to determine the most important areas for intervention and to monitor the effects of interventions. When designing a monitoring programme it is important to decide on the purpose of the programme. Thus, there are major differences between programmes designed to detect changes in a national population, individual herds or groups of animals. In addition, programmes have to be designed differently according to whether the aim is to determine changes in resistance for all antimicrobial agents or only the antimicrobial agents considered most important in relation to treatment of humans. In 1995 a continuous surveillance for antimicrobial resistance among bacteria isolated from food animals was established in Denmark. Three categories of bacteria, indicator bacteria, zoonotic bacteria and animal pathogens are continuously isolated from broilers, cattle and pigs and tested for susceptibility to antimicrobial agents used for therapy and growth promotion by disc diffusion or minimal inhibitory concentration determinations. This programme will only detect changes on a national level. However, isolating the bacteria and testing for several antimicrobial agents will enable us to determine the effect of linkage of resistance. Since 1995 major differences in the consumption pattern of different antimicrobial agents have occurred in Denmark. The Danish monitoring programme has enabled us to determine the effect of these changes on the occurrence of resistance. The Danish monitoring is, however, not suited to determine changes on a herd level or to detect emergence of new types of resistance only occurring at a low level.  相似文献   

4.
To determine the current status of antimicrobial susceptibility of bacterial pathogens from animals in Germany, the Bff-GermVet monitoring program was initiated as a complementary program to the German national monitoring program GERM-Vet conducted by the Federal Office of Consumer Protection and Food Safety (BVL). In the Bff-GermVet program, a total of 1,626 bacterial strains, obtained during a 27-month period (01/2004-03/2006) from 31 indications, was screened for susceptibility against 22 antimicrobial agents and two combinations of antimicrobial agents. Selected bacteria were additionally tested for their susceptibility against additional three combinations of antimicrobial agents and the corresponding single substances.This paper describes the overall aims and the structure of the program with particular reference to the sampling strategy, the methodology for susceptibility testing and the interpretive criteria used for evaluation of the results.  相似文献   

5.
Mastitis is one of the most important diseases in dairy cattle of which Staphylococcus aureus is a major pathogen. Despite an apparently good antimicrobial susceptibility in vitro, the cure of diseased animals from this bacteriological infection is often disappointing, which results in cases of recurrent clinical- and chronic subclinical infections. It has been suggested that these recurrent and chronic Staphylococcus infections can be attributed to the growth of bacteria in biofilm. The objective of this study was to compare the susceptibility for antimicrobial agents of S. aureus isolates obtained from bovine mastitis growing under different conditions. These conditions include a conventional conventional microbroth dilution assay in which minimal inhibitory concentration values are determined, the MBEC assay which measures both the susceptibility in biofilm and the susceptibility of sequester cells released from the biofilm. A comparison of the susceptibility for antimicrobial agents of a number of representative S. aureus isolates grown in broth (representing in vitro growth conditions) or milk (representing in vivo growth conditions) is also made. The results indicate that S. aureus isolates obtained from bovine mastitis are highly resistant to antimicrobial agents when growing in biofilms.  相似文献   

6.
Antimicrobials are essential medicines for the treatment of many microbial infections in humans and animals. Only a small number of antimicrobial agents with new mechanisms of action have been authorized in recent years for use in either humans or animals. Antimicrobial resistance (AMR) arising from the use of antimicrobial agents in veterinary medicine is a concern for public health due to the detection of increasing levels of resistance in foodborne zoonotic bacteria, particularly gram‐negative bacteria, and due to the detection of determinants of resistance such as Extended‐spectrum beta‐lactamases (ESBL) in bacteria from animals and in foodstuffs of animal origin. The importance and the extent of the emergence and spread of AMR from animals to humans has yet to be quantified. Likewise, the relative contribution that the use of antimicrobial agents in animals makes to the overall risk to human from AMR is currently a subject of debate that can only be resolved through further research. Nevertheless, risk managers have agreed that the impact on public health of the use of antimicrobials in animals should be minimized as far as possible and a variety of measures have been introduced by different authorities in the EU to achieve this objective. This article reviews a range of measures that have been implemented within European countries to reduce the occurrence and the risk of transmission of AMR to humans following the use of antimicrobial agents in animals and briefly describes some of the alternatives to the use of antimicrobial agents that are being developed.  相似文献   

7.
In-vitro susceptibility testing provides valuable informations for choosing the most suitable antimicrobial agent for the control of bacterial infections in animals. Different diffusion and dilution methods, as conducted according to various approved performance standards, can be used to determine the in-vitro susceptibility of bacterial pathogens. In the present article, problems are discussed which arise from the use of different methods and the difficulty to interpret such results. While most approved performance standards were designed for testing of bacteria from human sources, the NCCLS document M31-A2 exclusively focusses on susceptibility testing of bacteria isolated from animals and--in contrast to all other standards--includes veterinary specific breakpoints for a number of antimicrobial agents used in veterinary medicine. Therefore, performance of in-vitro susceptibility testing of veterinary pathogens should follow the recommendations given in the NCCLS document M31-A2. The microdilution method is recommended as the method of choice for susceptibility testing. The result of a microdilution test is given as the minimum inhibitory concentration (MIC). This value provides a quantitative result which precisely indicates the degree of susceptibility of the tested bacterial strain and in return gives the veterinarian a clear guidance whether therapeutic intervention with the antibiotic in question will be successful.  相似文献   

8.
Antimicrobial agent usage data are essential for focusing efforts to reduce misuse and overuse of antimicrobial agents in food producing animals because these practices may select for resistance in bacteria of animals. Transfer of resistant bacteria from animals to humans can lead to human infection caused by resistant pathogens. Resistant infections can lead to treatment failures, resulting in prolonged or more severe illness. Multiple World Health Organization (WHO) reports have concluded that both antimicrobial resistance and antimicrobial usage should be monitored on the national level. The system for collecting antimicrobial usage data should be clear and transparent to facilitate trend analysis and comparison within and among countries. Therapeutic, prophylactic and growth promotion use should be recorded, along with route of administration and animal species and/or production class treated. The usage data should be compared to resistance data, and the comparison should be made available in a timely manner. In the United States, surveillance of antimicrobial resistance in foodborne bacteria is performed by the National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria, however, the United States still lacks a mechanism for collecting antimicrobial usage data. Combined with antimicrobial resistance information from NARMS, antimicrobial usage data will help to direct education efforts and policy decisions, minimizing the risk that people will develop antimicrobial resistant infections as a result of eating food of animal origin. Ultimately mitigation strategies guided by usage data will be more effective in maintaining antimicrobial drugs for appropriate veterinary use and in protecting human health.  相似文献   

9.
The bacterial and fungal flora of 1118 ears of dogs with otitis externa and 100 ears of healthy control dogs were studied in order to isolate the causative agents. The yeast Malassezia pachydermatis (56%) was by far the most common organism in otitic dogs followed by the bacteria Staphylococcus intermedius (23%), Pseudomonas aeruginosa (12%), Proteus spp. (6%) and Streptococcus canis (5%). A statistical analysis of observed results showed that the incidence of these organisms is significant in otitic dogs. Many strains of S.intermedius, P.aeruginosa and Proteus spp. are resistant to antimicrobial agents commonly used to treat otitis externa. Therefore an antimicrobial susceptibility testing was performed using "Cobas Bact" for these bacterias. Furthermore, 80 strains of M.pachydermatis were submitted to identification-kits (API 20 CAUX, API STAPH, Cobas Micro). The observed results showed that an identification with these tests was not possible.  相似文献   

10.
In Germany, the application of antimicrobial agents represents the method of choice to control infections of food-producing animals by bacteria of the genus Leptospira. However, only few data are available on the susceptibility of Leptospira spp. against antimicrobial agents and the in vivo efficacy of antimicrobial agents. Based on a modified broth microdilution method, a standardised in-vitro susceptibility testing system for Leptospira spp. was established which also included quality control aspects. Considering the minimum inhibitory concentrations determined in this study in-vivo efficacy is expected for the following classes of antimicrobial agents: penicillins, cephalosporins, macrolides, lincosamides, fluoroquinolones, phenicols, and in part also for aminoglycosides and tetracyclines. Clinical aspects and bioavailability of the drugs in the target tissues have to be taken into account. Penicillins and aminoglycosides as commonly used inhibitory supplements in semen extender seem to be effective against leptospires.  相似文献   

11.
《中国兽药杂志》2012,46(9):50-53
动物源细菌耐药性问题不仅关系到动物的用药安全,也与公共卫生安全密切相关,日益引起各国的关注。中国兽医药品监察所从事动物源细菌耐药性检测工作10余年,对我国动物源细菌的耐药性状况进行了系统的调查。本文从动物源细菌耐药性监测工作的重要性、我国动物源细菌的耐药性状况、存在的问题以及应对策略四个方面进行了综述,以期对我国的动物源细菌耐药性监测工作起一定的参考作用。  相似文献   

12.
The estimated prevalence and antimicrobial resistances of Salmonella spp. in non‐diarrhoeic dogs across Trinidad was determined. The serotypes of Salmonella spp. isolated were also identified. Of a total of 1391 dogs sampled, 50 (3.6%) were positive for Salmonella spp. with 28 different serotypes, the predominant serotypes were Javiana (12), Newport (6), Arechavaleta (5) and Heidelberg (5). Fifty‐seven (85.1%) of 67 isolates exhibited resistance to one or more antimicrobial agents. Of eight antimicrobial agents tested, resistance was exhibited to streptomycin (80.6%), cephalothin (37.3%), neomycin (38.8%) and gentamicin (9.0%). All isolates were sensitive to ampicillin, norfloxacin, choramphenicol and sulphamethoxazole/trimethoprim. It was concluded that the isolation of the Salmonella spp. from non‐diarrhoeic dogs could pose health hazard to their owners as most serotypes are known to be virulent. Furthermore, the prevalence of resistance to antimicrobial agents amongst the Salmonella isolates from these animals indicates susceptibility testing may influence chemotherapeutic choices when treating these isolates.  相似文献   

13.
The application of antimicrobial agents has proved to be the main risk factor for development, selection and spread of antimicrobial resistance. This link applies to the use of antimicrobial agents in human and in veterinary medicine. Furthermore, antimicrobial-resistant bacteria and resistant genes can be transmitted from animals to humans either by direct contact or via the food chain. In this context, risk management has to be discussed regarding prevention and control of the already existing antimicrobial resistance. One of the primary risk management measures in order to control the development and spread of antimicrobial resistances is by regulating the use of antimicrobial agents and subjecting their use to guidelines. Thereby, the occurrence of antimicrobial resistant bacteria in the human and veterinary habitat can be controlled to a certain degree. There is little information about past attempts to prevent the development of resistances or to control them, and even less is known about the effectiveness or the cost intensiveness of such efforts. Most of the strategies focus on preventing and controlling antimicrobial resistance by means of the reduction or limitation of the use of antimicrobial agents in food-producing animals.  相似文献   

14.
Bacteria with antimicrobial resistance can be transferred from animals to humans and may compromise antimicrobial treatment in case of infection. To determine the antimicrobial resistance situation in bacteria from Swiss veal calves, faecal samples from 500 randomly selected calves originating from 129 farms were collected at four big slaughterhouses. Samples were cultured for Escherichia coli, Enterococcus sp. and Campylobacter sp. and isolated strains were tested for antimicrobial susceptibility to selected antimicrobial agents by the minimal inhibitory concentration technique using the broth microdilution method. From 100 farms, data on farm management, animal husbandry and antimicrobial treatments of the calves were collected by questionnaire. Risk factors associated with antimicrobial resistance were identified by logistic regression. In total, 467 E. coli, 413 Enterococcus sp. and 202 Campylobacter sp. were isolated. Of those, 68.7%, 98.7% and 67.8%, respectively, were resistant to at least one of the tested antimicrobial agents. Resistance was mainly observed to antimicrobials frequently used in farm animals. Prevalence of resistance to antimicrobials important for human treatment was generally low. However, a rather high number of quinupristin/dalfopristin-resistant Enterococcus faecium and ciprofloxacin-resistant Campylobacter sp. were detected. External calf purchase, large finishing groups, feeding of milk by-products and administration of antimicrobials through feed upon arrival of the animals on the farm significantly increased the risk of antimicrobial resistance at farm level. Participation in a quality assurance programme and injection of a macrolide upon arrival of the animals on the farm had a protective effect. The present study showed that veal calves may serve as a reservoir for resistant bacteria. To ensure food safety, veal calves should be included in the national monitoring programme for antimicrobial resistance in farm animals. By improving farm management and calf husbandry the prevalence of resistance may be reduced.  相似文献   

15.
兽用抗菌药耐药性已经成为一个全球普遍关注的公共健康问题,各国际组织都积极采取相应的措施控制耐药性的产生和蔓延。介绍了国际组织世界动物卫生组织OIE制定的五个国际标准,包括协调抗菌药耐药性监督和检测程序指南、畜牧业抗菌药消耗量监测指南、兽用抗菌药慎用指南、抗菌药敏感性检测的实验室方法指南、动物源抗菌药耐药性对公共健康潜在影响的风险分析方法指南,以期为我国政策制定者和决策者参照国际标准制定出符合我国国情的耐药性相关指南。  相似文献   

16.
细菌耐药性产生的原因、机制及防治措施   总被引：6，自引：4，他引：2  
20世纪40年代青霉素的问世将人类带入了抗生素时代,抗感染治疗由此进入了新纪元,感染性疾病的病死率大大降低。半个世纪以来,人类一直把抗菌药物作为抗感染治疗最有力的武器。然而随着抗菌药物的广泛应用,感染性疾病的治疗又遇到了新的挑战——细菌对抗生素产生了耐药性,而此种耐药性表现为抗菌药物使用得越多耐药性亦变得越严重。目前已发现某些细菌对现有的几乎全部抗菌药物产生耐药,超级细菌的出现使人类有可能再次回到面临感染而无药可医的困境,控制细菌耐药性的增长已成为医学界乃至全人类的当务之急。正在逐渐建立自己的细菌耐药监测网络,监测细菌耐药的流行状况和规律,研究细菌产生耐药性的机制。  相似文献   

17.
Thein vitro synergistic effects of combinations of EDTA-tromethamine and five antimicrobial agents (ampicillin, cephalexin, oxytetracycline, streptomycin and sulphadimethoxine) on three clinically isolated Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis andStreptococcus faecium) were investigated. The bacteria had been isolated from three cases of canine otitis resistant to -lactam antibiotic therapy. The antimicrobial activity was evaluated by measuring the minimal inhibitory concentration for the antibiotics alone or in combination with EDTA-tromethamine. EDTA-tromethamine potentiated the activity of cefalexin againstS. aureus andS. hominis, of oxytetracycline againstS. aureus andS. faecium and of streptomycin againstS. faecium. No significant effects were noted on the activity of oxytetracycline againstS. hominis. The remaining combinations gave a slight synergistic effect. As previously shown for Gram-negative resistant bacteria, these data suggest that the association of EDTA-tromethamine and appropriate antibiotic therapy may be useful to overcome persistent infections of soft tissues in domestic animals.Abbreviations cfu colony forming units - EDTA ethylenediaminetetraacetic acid - MIC minimal inhibitory concentration - tromethamine tris(hydroxymethyl)- aminomethane Part of this paper was communicated at the XLVI Congress of the Italian Society of Veterinary Sciences, Venice, 30 September – 3 October 1992  相似文献   

18.
Flavobacterium columnare and F. psychrophilum are major fish pathogens that cause diseases that may require antimicrobial therapy. Choice of appropriate treatment is dependent upon determining the antimicrobial susceptibility of isolates. Therefore we optimized methods for broth microdilution testing of F. columnare and F. psychrophilum to facilitate standardizing an antimicrobial susceptibility test. We developed adaptations to make reproducible broth inoculums and confirmed the proper incubation time and media composition. We tested the stability of potential quality-control bacteria and compared test results between different operators. Log phase occurred at 48 h for F. columnare and 72–96 h for F. psychrophilum, confirming the test should be incubated at 28°C for approximately 48 h and at 18°C for approximately 96 h, respectively. The most consistent susceptibility results were achieved with plain, 4-g/L, dilute Mueller–Hinton broth supplemented with dilute calcium and magnesium. Supplementing the broth with horse serum did not improve growth. The quality-control strains, Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658, yielded stable minimal inhibitory concentrations (MIC) against all seven antimicrobials tested after 30 passes at 28°C and 15 passes at 18°C. In comparison tests, most MICs of the isolates agreed 100% within one drug dilution for ampicillin, florfenicol, and oxytetracycline. The agreement was lower with the ormetoprim–sulfdimethoxine combination, but there was at least 75% agreement for all but one isolate. These experiments have provided methods to help standardize antimicrobial susceptibility testing of these nutritionally fastidious aquatic bacteria.

Received June 24, 2015; accepted October 2, 2015.  相似文献   


19.
beta-Lactams are among the most clinically important antimicrobials in both human and veterinary medicine. Bacterial resistance to beta-lactams has been increasingly observed in bacteria, including those of animal origin. The mechanisms of beta-lactam resistance include inaccessibility of the drugs to their target, target alterations and/or inactivation of the drugs by beta-lactamases. The latter contributes predominantly to beta-lactam resistance in Gram-negative bacteria. A variety of beta-lactamases have been identified in bacteria derived from food-producing and companion animals and may further serve as a reservoir for beta-lactamase-producing bacteria in humans. While this review mainly describes beta-lactamases from animal-derived Escherichia coli and Salmonella spp., beta-lactamases from animal-derived Campylobacter spp., Enterococcus spp., Staphylococcus spp. and other pathogens are also discussed. Of particular concern are the increasingly-isolated plasmid-encoded AmpC-type CMY and extended-spectrum CTX-M beta-lactamases, which mediate acquired resistance to extended-spectrum beta-lactams. The genes encoding these enzymes often coexist with other antimicrobial resistance determinants and can also be associated with transposons/integrons, increasing the potential enrichment of multidrug resistant bacteria by multiple antimicrobial agents as well as dissemination of the resistance determinants among bacterial species. Characterization of beta-lactam-resistant animal-derived bacteria warrants further investigation of the type and distribution of beta-lactamases in bacteria of animal origin and their potential impact on human medicine.  相似文献   

20.
The determination of quantitative data (minimal inhibitory concentrations [MIC values]) using the broth microdilution method is considered the method of choice for in-vitro susceptibility testing of bacterial pathogens. For the inoculation of microtiter plates used in the broth microdilution method, an inoculation density of 5x10(5) CFU/ml has to be achieved according to the CLSI standard. In this study, it was shown that the requested CFU/ml corresponded to an optical density of 0.00027 of a bacterial suspension determined in a spectrophotometer at 625 nm (OD625).The comparison of susceptibility data of clinical isolates determined by agar disk diffusion and, in parallel, by broth microdilution confirmed the comparability of both methods. For most antibiotics the frequency of "very major errors" was below 10%. However, a higher frequency of errors was observed for combinations of antimicrobial agents and bacteria for which no valid breakpoints are available. The comparative testing of cephalothin showed a frequency of"very major errors" of 20.3% for staphylococci and 18.4% for Enterobacteriaceae; for apramycin the frequency of "major errors"was found to be 46.0% for Enterobacteriaceae. The reference strains as recommended in the CLSI Standard M31-S1 should be used for quality assurance.  相似文献   

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