我国动物源细菌耐药状况、存在问题和对策

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。     

细菌耐药性基因与食品卫生安全

动物致病性细菌耐药性的发生和扩散不仅使许多常规抗生素在治疗动物细菌性疫病中失去了疗效,而且还引发了人们盲目投药、过量用药、应用新开发药的错误的治疗行为。这种错误的治疗行为反过来进一步促进了细菌耐药性的发生、传播和扩散。这种耐药性增加的恶性循环有其根本的物质基础,即细菌耐药性决定因子———细菌耐药性基因。细菌耐药性基因增多和扩散机制的存在,可使动物源性食品所携带的无害常在菌,譬如普通的大肠杆菌会从致病菌那儿传递上耐药性基因。这种耐药性基因可通过人类食用此类食品传递给人体内的细菌,而使许多抗生素在治疗人…     

我国动物源细菌耐药性监测系统简介

本文介绍了我国动物源细菌耐药性监测网络的组成和主要内容,详细阐述了其过程控制,包括采样、细菌分离鉴定和耐药性检测、耐药性检测结果汇总分析等,并介绍了我国取得的成就,如建立了动物源细菌耐药性监测技术平台和耐药性细菌资源库、创建了具有自主知识产权的动物源细菌耐药性数据库、摸清了我国动物源细菌的耐药性状况等。针对我国动物源细菌的耐药现状,提出了应对措施,包括规范我国兽用抗菌药物饲料添加剂的使用、加强动物处方药的管理并建立治疗用抗菌药物的分级管理制度、持续开展畜禽细菌耐药性动态监测等。     

我国动物源细菌耐药性数据库的建立与应用

为加强全国动物源细菌耐药性监测数据统一管理,实时掌握我国动物源细菌耐药性的流行动态,中国兽医药品监察所联合多家国内细菌耐药性监测单位,开发了我国的动物源细菌耐药性监测数据库。该数据库为B/S架构,全国不同地区动物源细菌耐药性监测实验室均可通过网页浏览器连接服务器,实现了监测数据即时储存、统计分析和上报,为我国兽医临床细菌耐药性监测提供了重要的技术支持。     

要闻

农业部印发《2013年动物源细菌耐药性监测计划》根据《兽药管理条例》规定,为做好2013年度动物源细菌耐药性监测工作,进一步提高我国细菌耐药性监测能力,农业部特制定《2013年动物源细菌耐药性监测计划》。各监测任务承担单位的采样、细菌分离和鉴定、耐药性检测和结果上报等活动要按照《动物源细菌耐药性检测采样、检测技术要点》;样品应从畜禽养殖场、屠宰     

一个值得高度关注的问题——动物源细菌耐药性

由于动物源细菌耐药性关乎到人类健康,使得畜禽疾病防控和公共卫生安全日益受到全世界的普遍关注。本文就动物源细菌耐药性的危害、我国动物源细菌的耐药性状况、发展趋势及应对策略进行了综述,以期对我国开展动物源细菌耐药性检测和制定预防对策提供参考。     

兽药

正农业部印发《2017年动物源细菌耐药性监测计划》2月9日,农业部印发《2017年动物源细菌耐药性监测计划》(以下简称《监测计划》),至此动物源细菌耐药性监测工作正式展开。此次公布的动物源细菌耐药性监测计划中就要求各地兽医行政管理部门对辖区内动物肠道菌群血清     

我国动物源细菌耐药性监测及预警的研究进展

利用调查和数据统计报道我国近年来的兽用抗生素使用、养殖业用药背景、抗菌药物耐药、动物源细菌耐药性监测、动物源细菌耐药监测数据库研究及国家制定的相关政策等现状,并针对我国动物源细菌的耐药和监测现状,提出了我国政府与各地区相关部门应科学评估分析动物源细菌耐药性监测数据及变化趋势;借鉴发达国家的经验和方法,完善我国动物源细菌耐药性监测网络和监测体系;加强教育和宣传等应对措施,为解决全球动物源细菌耐药性问题作出贡献。     

2020年动物源细菌耐药性监测工作总结会在京召开

近日,中国兽医药品监察所在北京召开2020年动物源细菌耐药性监测工作总结会。中国兽医药品监察所副所长高光、农业农村部畜牧兽医局药政药械处副处长冯华兵及相关专家出席会议。会议总结了2020年全国动物源细菌耐药性监测工作情况,全面分析了我国动物源细菌耐药性变化趋势,讨论了耐药性监测工作中存在的问题及改进措施,研究制定了2021年动物源细菌耐药性监测计划。     

动物源细菌耐药性监测与流行病学研究

全面分析了开展动物源细菌耐药性监测与流行病学研究的必要性和紧迫性,介绍了动物源细菌耐药性监测与流行病学研究的国外概况和国内现状,指出当前我国在该领域内存在的问题,提出6点建议以期做好动物源细菌耐药性的防控工作。     

黄酮类化合物抗菌作用及机制的研究进展

随着抗菌药物在临床预防与治疗中的广泛应用,细菌耐药性问题日趋严重,泛耐药菌株及多重耐药菌株显著增多。中草药因其特殊的抗菌机制而不易产生耐药性,使得抗耐药菌中草药的研发及其抗菌机制的研究越来越受到人们的关注。天然存在的黄酮类化合物具有一定的抗菌活性,其中大部分种类对金黄色葡萄球菌、链球菌和枯草杆菌等革兰氏阳性菌的抑制作用较明显,不良反应相对较轻,且不易出现耐药性。文章就黄酮类化合物的抗菌作用及机制作一综述。     

Associations among antimicrobial drug treatments and antimicrobial resistance of fecal Escherichia coli of swine on 34 farrow-to-finish farms in Ontario, Canada

Logistic regression was used to model associations between antimicrobial treatment and resistance among fecal Escherichia coli of finisher pigs at the farm level. Four sets of potential risk factors representing different levels of refinement of antimicrobial use on farms were modelled on resistance to antimicrobials. Final models for each antimicrobial were constructed from treatment and management variables significant on initial screening, and corrections for overdispersion were made. In general, in-feed antimicrobial treatment of pigs was more consistently associated with an increased risk of resistance than individual-animal treatment. Antimicrobial treatment in starter rations was significant in final models of resistance to ampicillin, carbadox, nitrofurantoin, sulfisoxizole, and tetracycline. Treatment in grower–finisher rations was significantly associated with resistance to ampicillin, spectinomycin, sulfisoxizole, and tetracycline. There was little evidence that in-feed antimicrobials increased the risk of resistance to gentamicin, which is a drug used only for individual-pig treatment in this study population. These results suggest that antimicrobial medication of rations of post-weaning pigs selects for and maintains antimicrobial resistance among E. coli of finisher pigs. Although resistance was common on farms that did not medicate rations of post-weaning pigs, the results indicate that antimicrobial use does increase the risk of resistance to the antimicrobials studied.     

Antimicrobial resistance in Salmonella enterica serovar Dublin isolates from beef and dairy sources

Salmonella enterica serovar Dublin (S. Dublin) is a cattle-adapted Salmonella serovar, so if antimicrobial resistance in S. Dublin arises as a result of antimicrobial use this most likely occurs within the cattle reservoir without impact from antimicrobial use in humans. We tested the antimicrobial resistance of bovine-origin S. Dublin isolates from 1986 through 2004 using a standard disk diffusion method. High proportions of isolates throughout the time period were resistant to one or more antimicrobials, and a marked increase in resistance to ceftazidime occurred between 2000 and 2004. Dairy-origin isolates were more likely to be resistant to several antibiotics than were isolates from beef operations where exposure to antimicrobials is likely to be less frequent. Plasmid analysis of a subset of isolates also supported the hypothesis that antimicrobial resistance traits in the cattle-adapted serovar Dublin were acquired within the bovine host environment.     

山东省部分地区禽源致病性大肠杆菌的血清流行病学调查与耐药性检测

为调查山东省禽源致病性大肠杆菌流行的血清型及耐药性,从山东部分地区的45家养禽场分离到致病性大肠杆菌96株,应用微量平板凝集试验进行了血清型鉴定,共鉴定出18种血清型,其中优势血清型6种,分别为O78、O2、O15、O18、O143、O88,占定型致病性菌株的64％。抗菌药物敏感性试验发现,96株大肠杆菌对20种药物有不同程度的耐药性。75％以上的菌株对氨苄青霉素、阿莫西林、土霉素等5种抗菌药耐药,50％以上的菌株对卡那霉素、多西环素、环丙沙星等7种抗菌药表现为耐药;所有分离株存在多重耐药现象,75％的受检菌对9种或9种以上的被测药物耐药。结果表明,O78、O2、O15、O18、O143、O886种血清型是山东省部分地区近年来禽源致病性大肠杆菌的优势血清型,且禽源致病性大肠杆菌的耐药现象严重,有必要加强耐药性检测,以指导兽医临床合理使用抗菌药物。     

全基因组测序技术在猪源沙门氏菌血清分型和耐药性分析中的应用

【目的】为研究全基因组测序技术在猪源沙门氏菌血清型和耐药性检测方面的应用能力。【方法】以60株猪源沙门氏菌为研究对象,应用传统玻片凝集法和微量肉汤稀释法对其进行血清分型和耐药性检测,并提取所有菌株核酸进行全基因组测序组装,利用SeqSero2和ResFinder4在线预测每株菌的血清型和耐药基因,然后与传统方法进行比较分析。【结果】血清凝集试验共鉴定出8种沙门氏菌血清型,而全基因组测序鉴定出9种血清型,二者分型结果的符合率为90.0%;对11种抗菌药物的药敏试验显示：沙门氏菌对四环素（73.3%）的耐药率最高,其次为氨苄西林（66.7%）、磺胺异噁唑（66.7%）和复方新诺明（53.3%）,基于全基因组预测的恩诺沙星、美罗培南、头孢噻呋和阿奇霉素的耐药性与药敏试验结果完全一致,对氨苄西林、磺胺异噁唑、四环素预测的结果符合率也均大于90.0%。【结论】全基因组测序分析的沙门氏菌血清型和耐药性与常规检测方法的符合率较高,且具有操作简便的优势,可以作为分析沙门氏菌血清型和耐药性的有效方法。     

Veterinary use of antimicrobials and emergence of resistance in zoonotic and sentinel bacteria in the EU

Antimicrobials are essential for treatment of sick animals, but even if used correctly, may eventually lead to antimicrobial resistance. While this represents a potential hazard to humans, the great majority of resistant human pathogens, especially the more important ones, are unrelated to animal sources. A survey of informed medical opinion suggested that of the human antimicrobial resistance problem, <4% was seen as potentially linked to animal sources. This proportion related largely to zoonotic bacteria which by definition have the capacity to carry resistance between species, although the evidence for resulting harm remains limited. A recent study compared resistance among chicken, pig and cattle isolates of Salmonella spp., Campylobacter spp. and Escherichia coli from a series of EU countries. When tested against antimicrobial agents, this survey showed variation of resistance between countries, between hosts and between organisms. Such variation may give insight into preferred methods of antimicrobial administration or disease control, but it is clear that the epidemiology of antimicrobial resistance induction and dissemination in animals remains complex and is yet to be fully understood.     

Public health and policy

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.     

Cross-resistance between antimicrobial agents used in veterinary medicine: molecular background and practical consequences for susceptibility testing

Phenotypic resistance of veterinary pathogens to more than one antimicrobial agent (multi-resistance) may be caused by intrinsic resistance to the antimicrobial agents, acquired cross-resistance, or acquired co-resistance. Known cross-resistances allow to select so-called "representative substances" which are tested and the results of which can also be regarded as being valid for other members of the same class of antimicrobial agents. In general, a limitation in the number of antimicrobial agents to be tested in routine diagnostics is necessary because of capacity and cost efficiency. This is of particular relevance when the broth microdilution method - recommended as the method of choice - with 96-well microtiter plates is used. The knowledge about the relationship between different resistance phenotypes and the corresponding resistance mechanisms is of major value for both, the laboratory personnel and the veterinary practitioner. This review explains how "representative substances" for the most relevant classes of antimicrobial agents used in veterinary medicine are chosen on the basis of known cross-resistances.     

Impact of hospitalization and antimicrobial drug administration on antimicrobial susceptibility patterns of commensal Escherichia coli isolated from the feces of horses

Objective-To evaluate antimicrobial susceptibility of commensal Escherichia coli strains isolated from the feces of horses and investigate relationships with hospitalization and antimicrobial drug (AMD) administration. Design-Observational study. Animals-68 hospitalized horses that had been treated with AMDs for at least 3 days (HOSP-AMD group), 63 hospitalized horses that had not received AMDs for at least 4 days (HOSP-NOAMD group), and 85 healthy horses that had not been hospitalized or treated with AMDs (community group). Procedures-Fecal samples were submitted for bacterial culture, and up to 3 E coli colonies were recovered from each sample. Antimicrobial susceptibility of 724 isolates was evaluated. Prevalence of resistance was compared among groups by use of log-linear modeling. Results-For 12 of the 15 AMDs evaluated, prevalence of antimicrobial resistance differed significantly among groups, with prevalence being highest among isolates from the HOSP-AMD group and lowest among isolates from the community group. Isolates recovered from the HOSP-AMD and HOSP-NOAMD groups were also significantly more likely to be resistant to multiple AMDs. Resistance to sulfamethoxazole and resistance to trimethoprim-sulfamethoxazole were most common, followed by resistance to gentamicin and resistance to tetracycline. Use of a potentiated sulfonamide, aminoglycosides, cephalosporins, or metronidazole was positively associated with resistance to 1 or more AMDs, but use of penicillins was not associated with increased risk of resistance to AMDs. Conclusion and Clinical Relevance-Results suggest that both hospitalization and AMD administration were associated with prevalence of antimicrobial resistance among E coli strains isolated from the feces of horses.