水环境中耐药菌污染与危害研究进展

细菌在抗菌药选择性压力下产生耐药性并可传代,通过质粒和整合子等可移动基因元件将耐药基因在相同或不同种属中广泛传播,导致细菌多重耐药,并可通过多种途径进入水体,水环境日益成为庞大的耐药基因库,为致病菌及条件致病菌提供获得大量耐药基因的机会,若多重耐药菌再次侵入人体,可能引发严重的公共卫生问题。     

Multiple antibiotic resistance of heterotrophic bacteria in the littoral zone of Lake Shira as an indicator of human impact on the ecosystem

Resistance to Ampicillin and Kanamycin displayed by heterotrophic bacteria isolated in Summer and in Spring from the littoral and the central parts of Lake Shira (a therapeutic lake in the Khakasia Republic, Russia) has been investigated. It has been found that in Summer, human and animal microflora featuring multiple antibiotic resistance (to Ampicillin and Kanamycin) predominates in all the studied stations of the littoral zone of the lake. In Spring, concentrations of bacteria featuring multiple antibiotic resistance decrease significantly and bacteria sensitive to antibiotics predominate in the lake. Emergence of multiple antibiotic resistance in bacteria of Lake Shira is caused by the input of allochthonous bacteria into the lake; this feature of heterotrophic bacteria of Lake Shira can be used to monitor the impact on the ecosystem made by health resorts.     

儿童细菌性腹泻病原菌分布及耐药性分析

目的 了解小儿细菌性腹泻的病原菌分布及耐药情况。方法 对773例临床上疑为细菌性腹泻病的患儿的粪便标本进行培养、鉴定及药物敏感试验、超广谱β-内酰胺酶（ESBLs）检测。结果 773例标本中分离出阳性菌株671株,总检出率为86．6％。其中埃希菌属、志贺菌属及耶尔森菌3种致病性细菌占阳性菌株的54．5％,肠杆菌属、非发酵菌群、酵母样真菌、肠球菌属、变形杆菌属、克雷伯菌属和枸橼酸杆菌属等条件致病菌占阳性菌株的45．5％。埃希菌属及志贺菌属对头孢他啶及氨曲南耐药率低（16．4％以下）,而肠杆菌属等条件致病菌对常用抗生素耐药率均较高。G^-杆菌中ESBLs的检出率为38．3％,其中大肠埃希菌占66．7％。结论 埃希菌属是儿童细菌性腹泻病的主要致病菌（50．2％）,且耐药率及ESBLs产生率高,但肠杆菌属等条件致病菌检出率也较高（45．5％）,且耐药率高,可能与抗生素广泛使用,肠杆菌群失调有关,应引起高度重视。     

重症监护病房常见病原菌的分布及耐药性分析

目的了解滨州市人民医院重症监护病房(ICU)常见病原菌种类及分布,并分析其耐药性的变迁,为临床合理应用抗菌药物提供依据。方法对2011年1月1日至2013年12月31日我院ICU住院患者各类标本分离的病原菌进行培养,应用BD PhoenixTM-100全自动微生物鉴定仪鉴定细菌菌种,K-B法进行药敏试验检测,WHONET 5.6软件进行统计分析。结果 3年共收集3 449份标本,检出非重复病原菌1 802株,阳性分离率为52.25%,其中革兰阴性菌1 399株占77.64%,以鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌为主;革兰阳性菌275株占15.26%,以葡萄球菌和肠球菌为主;真菌128株占7.10%,以白色假丝酵母菌为主。主要致病革兰阴性杆菌对亚胺培南和美罗培南敏感,而对替卡西林、头孢他啶及哌拉西林均耐药;革兰阳性菌对万古霉素、替考拉宁、呋喃妥因、利奈唑胺及氯霉素敏感,而对青霉素耐药率高达100.00%。鲍曼不动杆菌、大肠埃希菌、肺炎克雷伯菌的ESBLs检出率分别为81.47%、74.19%和56.26%。结论我院ICU病原菌以革兰阴性杆菌为主,对大多数常用抗生素的耐药率较高,应加强病原菌耐药性的监测,为临床医生合理应用抗菌药物提供依据。     

动物源细菌耐药性研究现状与对策

目前我国动物源细菌耐药现象十分普遍,多重耐药甚至泛耐药的菌株不断出现,给公共卫生和食品安全造成了重大威胁。文中从我国动物源耐药性研究的主要问题、细菌耐药性形成和传播机制以及耐药性防控策略等几个方面进行综述,以期为耐药性的研究和防控提供参考。     

Assessment of environmental enterococci: bacterial antagonism,pathogenic capacity and antibiotic resistance

The properties of 166 environmental strains belonging to the seven enterococcal species were studied. Enterococci originated mainly from surface- and waste-waters. They were screened for the presence of enterocins, virulence factors, and antibiotic resistance. The presence of different enterocin genes (entA, entB, entP, ent31, entL50AB) was frequently observed in our enterococcal isolates, 109 strains contained at least one enterocin gene. The distribution of enterocin genes varied according to the species, the genes were present mainly in E. hirae and E. faecium. By enterocin spot assay, 10 isolates inhibited the growth of Listeria strains. To evaluate the pathogenic ability of isolates, the distribution of selected virulence genes (cylA, gelE and esp) was investigated, eleven strains were positive in some of these genes, five of them belonged to E. faecalis. Regarding the antibiotic resistance of isolates, only two strains were multiresistant and two strains (E. hirae and E. casseliflavus) were resistant to vancomycin.     

Tolerance of pesticides and antibiotic resistance in bacteria isolated from wastewater-irrigated soil

A total of 64 bacterial isolates (40 Pseudomonas spp., 12 Azotobacter and 12 Rhizobium spp.) were characterized on the basis of morphological, cultural and biochemical characteristics. All the isolates were tested for their tolerance to the pesticides endosulfan, carbofuran, and malathion. 12.5% of the Pseudomonas isolates from soil tolerated concentrations of 1600 g malathion ml whereas 7.5% of isolates tolerated the same concentration of carbofuran. However, Pseudomonas isolates demonstrated a tolerance limit to endosulfan at a concentration of 800 g/ml. Asymbiotic N₂-fixers (Azotobacter) and symbiotic N₂-fixers (Rhizobium spp.) were also able to tolerate concentrations of pesticides up to 1600 g/ml. All the isolates were further tested for their antibiotic susceptibility against seven different antibiotics, nalidixic acid, cloxacillin, chloramphenicol, tetracycline, amoxycillin, methicillin, doxycycline. 100% of the Pseudomonas isolates were resistant to cloxacillin and 57.5% were resistant to methicillin. 7.5% of the isolates exhibited multiple resistance to five different antibiotics in three different combinations whereas 25% of the isolates showed multiple resistance to four different antibiotics in seven different combinations. Some of the resistant isolates were also screened for plasmid DNA and found to harbour a single plasmid.     

幽门螺杆菌抗生素耐药机制研究进展

幽门螺杆菌(Helicobacter pylori,H.pylori)感染可引起消化性溃疡、胃粘膜相关淋巴组织淋巴瘤和胃癌。随着抗生素耐药性的问题越来越严重,耐药机制的研究也不断深入。分子检测方法,尤其是核酸检测技术,可高效、快速、准确地检测幽门螺杆菌抗生素耐药基因及突变,对幽门螺杆菌感染的临床治疗发挥重要的指导作用,同时也可对幽门螺杆菌抗生素耐药性进行大规模及时有效监控。本文讨论了关于幽门螺杆菌抗生素耐药机制并着重总结了相关耐药基因及突变。     

Proteomics in antibiotic resistance and tolerance research: Mapping the resistome and the tolerome of bacterial pathogens

Antibiotic resistance, the ability of a microbial pathogen to evade the effects of antibiotics thereby allowing them to grow under elevated drug concentrations, is an alarming health problem worldwide and has attracted the attention of scientists for decades. On the other hand, the clinical importance of persistence and tolerance as alternative mechanisms for pathogens to survive prolonged lethal antibiotic doses has recently become increasingly appreciated. Persisters and high-tolerance populations are thought to cause the relapse of infectious diseases, and provide opportunities for the pathogens to evolve resistance during the course of antibiotic therapy. Although proteomics and other omics methodology have long been employed to study resistance, its applications in studying persistence and tolerance are still limited. However, due to the growing interest in the topic and recent progress in method developments to study them, there have been some proteomic studies that yield fresh insights into the phenomenon of persistence and tolerance. Combined with the studies on resistance, these collectively guide us to novel molecular targets for the potential drugs for the control of these dangerous pathogens. In this review, we surveyed previous proteomic studies to investigate resistance, persistence, and tolerance mechanisms, and discussed emerging experimental strategies for studying these phenotypes with a combination of adaptive laboratory evolution and high-throughput proteomics.     

尿培养中病原菌分布及耐药性分析

目的研究大连市中心医院2007年1月至2012年9月尿培养中常见病原菌（真菌除外）的分布及其耐药性,为临床治疗尿路感染提供诊断及用药依据。方法采用MicroScan—Walkaway40全自动微生物鉴定药敏分析仪和ATBExpression自动细菌鉴定仪及K—B纸片法药敏试验,应用WHONET5．4软件对结果进行回顾性统计分析。结果五年间尿培养中共分离出病原菌1012株（真菌除外）,其中革兰阴性菌802株（79．2％）,主要是大肠埃希菌538株（53．2％）、肺炎克雷伯菌95株（9．5％）、铜绿假单胞菌51株（5．1％）、奇异变形杆菌30株（2．9％）、鲍曼不动杆菌26株（2．6％）。革兰阳性菌210株（20．8％）,主要是粪肠球菌86株（8．6％）,屎肠球菌83株（8．2％）,凝固酶阴性葡萄球菌21株（2．1％）,金黄色葡萄球菌13株（1．3％）。抗生素敏感试验中碳青霉烯类（亚胺培南及美洛培南）对肠杆菌科细菌大肠埃希菌、肺炎克雷伯菌及奇异变形杆菌抗菌活性最强,无耐药菌株,对非发酵菌中铜绿假单胞菌和鲍曼不动杆菌耐药率为30％～40％,革兰阳性菌对糖肽类（万古霉素、替考拉宁）和利奈唑胺等抗菌药物高度敏感。结论应当根据主要易感菌种类及其抗生素敏感试验结果指导临床合理使用抗生素。     

Evolution of antibiotic resistance by human and bacterial niche construction

Antibiotic treatment by humans generates strong viability selection for antibiotic-resistant bacterial strains. The frequency of host antibiotic use often determines the strength of this selection, and changing patterns of antibiotic use can generate many types of behaviors in the population dynamics of resistant and sensitive bacterial populations. In this paper, we present a simple model of hosts dimorphic for their tendency to use/avoid antibiotics and bacterial pathogens dimorphic in their resistance/sensitivity to antibiotic treatment. When a constant fraction of hosts uses antibiotics, the two bacterial strain populations can coexist unless host use-frequency is above a critical value; this critical value is derived as the ratio of the fitness cost of resistance to the fitness cost of undergoing treatment. When strain frequencies can affect host behavior, the dynamics may be analyzed in the light of niche construction. We consider three models underlying changing host behavior: conformism, the avoidance of long infections, and adherence to the advice of public health officials. In the latter two, we find that the pathogen can have quite a strong effect on host behavior. In particular, if antibiotic use is discouraged when resistance levels are high, we observe a classic niche-construction phenomenon of maintaining strain polymorphism even in parameter regions where it would not be expected.     

上呼吸道感染患儿咽部病原菌分布及耐药性分析

目的了解天津滨海地区儿童上呼吸道感染病原菌情况及耐药性,以便指导临床合理用药。方法对2012年1月至2013年4月天津市滨海新区汉沽中医医院住院儿科1022例上呼吸道感染儿童咽拭子标本进行培养及鉴定。采用法国ATB自动细菌鉴定仪及MIC药敏板进行细菌鉴定和药敏试验,β-内酰胺酶试验采用头孢硝噻吩纸片法,耐甲氧西林金黄色葡萄球菌（MRSA）采用头孢西丁纸片法检测。结果检出病原菌296株,其中金黄色葡萄球菌、肺炎链球菌及流感嗜血杆菌检出率分别为13. 70%、5. 97% 、5. 19%,分列前三位。金黄色葡萄球菌对常用抗菌药物耐药率为苯唑西林30. 0%、青霉素95. 7%、红霉素80. 0%、左氧氟沙星4. 3%,MRSA占30. 0% （42/140）、;肺炎链球菌对常用抗菌药物耐药率为青霉素9. 84%、红霉素54. 1%、克林霉素52.5%、左氧氟沙星3. 3% ;流感嗜血杆菌对常用抗菌药物耐药率为氨苄西林34. 0%、阿奇霉素0%、左氧氟沙星0%,复方新诺明56. 6%、头孢呋辛3. 8%、阿莫西林/克拉维酸5. 7%。结论天津滨海地区儿童上呼吸道感染病原菌分布广泛,检出致病菌有一定的耐药率,临床应重视根据病原菌感染情况及药敏试验结果,进行耐药性监测和合理用药。     

Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources

This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole (25 μg), Nalixidic acid (30 μg), Trimethoprim (1.25 μg), Novobiocin (5 μg), Penicilin (10 μg) and Chloramphenicol (10 μg) was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%), Kanamycin (5.7%), Gentamicin (5.7%) and Oxytetracycline (24.5%). Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.     

Engineering antibiotic production and overcoming bacterial resistance

Progress in DNA technology, analytical methods and computational tools is leading to new developments in synthetic biology and metabolic engineering, enabling new ways to produce molecules of industrial and therapeutic interest. Here, we review recent progress in both antibiotic production and strategies to counteract bacterial resistance to antibiotics. Advances in sequencing and cloning are increasingly enabling the characterization of antibiotic biosynthesis pathways, and new systematic methods for de novo biosynthetic pathway prediction are allowing the exploration of the metabolic chemical space beyond metabolic engineering. Moreover, we survey the computer-assisted design of modular assembly lines in polyketide synthases and non-ribosomal peptide synthases for the development of tailor-made antibiotics. Nowadays, production of novel antibiotic can be tranferred into any chosen chassis by optimizing a host factory through specific strain modifications. These advances in metabolic engineering and synthetic biology are leading to novel strategies for engineering antimicrobial agents with desired specificities.     

Direction of aminoacylated transfer RNAs into antibiotic synthesis and peptidoglycan-mediated antibiotic resistance

Prokaryotic aminoacylated-transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated-tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross-linkage or change in membrane permeability is often a prerequisite for high-level antibiotic resistance. In Streptomycetes, aminoacylated-tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated-tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.     

A rapid method for the determination of antibiotic resistance in bacterial pathogens within diseased specimens

A technique was developed, which permitted the rapid determination of antibiotic resistance of bacterial pathogens in diseased material. The method involved use of an antibody-based antigen capturing system, exposure to antibiotic solutions, and thence the determination of viability by reduction of thiazolyl blue.     

不同时期肠杆菌科细菌产ESBLS及耐药性的监测

目的对不同时期肠杆菌科细菌产超广谱β-内酰胺酶（ESBLS）及耐药性进行监测。方法采用生物梅里埃ATB药敏试验板测定肠杆菌科细菌中大肠埃希菌和肺炎克雷伯菌对抗生素的敏感性,同时用表型确证法检测ESBLS。结果肠杆菌科细菌2006-2008年与2009-2011年两个时期相比,ESBLS的检出率增长近50%。对亚胺配南、头孢吡肟、头孢西丁耐药率较低,对哌拉西林/他唑巴坦、阿米卡星的耐药率次之,对其他β-内酰胺类、氨基糖苷类、喹诺酮类及磺胺类抗生素的耐药率较高,且两个时期相比耐药率增加明显,差异具有统计学意义（P〈0.05）。结论临床产ESBLS菌株不断增多,多重耐药现象越来越严重,临床实验室应当把ESBLS的检测作为常规监测工作,有效指导临床选用抗菌药物。     

Copper amendment of agricultural soil selects for bacterial antibiotic resistance in the field

AIMS: The objective of this study was to determine whether Cu-amendment of field plots affects the frequency of Cu resistance, and antibiotic resistance patterns in indigenous soil bacteria. METHODS AND RESULTS: Soil bacteria were isolated from untreated and Cu-amended field plots. Cu-amendment significantly increased the frequency of Cu-resistant isolates. A panel of isolates were characterized by Gram-reaction, amplified ribosomal DNA restriction analysis and resistance profiling against seven antibiotics. More than 95% of the Cu-resistant isolates were Gram-negative. Cu-resistant Gram-negative isolates had significantly higher incidence of resistance to ampicillin, sulphanilamide and multiple (> or =3) antibiotics than Cu-sensitive Gram-negative isolates. Furthermore, Cu-resistant Gram-negative isolates from Cu-contaminated plots had significantly higher incidence of resistance to chloramphenicol and multiple (> or =2) antibiotics than corresponding isolates from control plots. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this field experiment show that introduction of Cu to agricultural soil selects for Cu resistance, but also indirectly selects for antibiotic resistance in the Cu-resistant bacteria. Hence, the widespread accumulation of Cu in agricultural soils worldwide could have a significant effect on the environmental selection of antibiotic resistance.     

Hygienic quality and antibiotic resistance profile of sliced butchery

In order to investigate the microbiological quality of different meat products on the Greek market, 200 samples were collected from the following preparations: boiled turkey (n = 50), boiled pork ham (n = 50), smoked turkey (n = 50) and smoked pork ham (n = 50).In all cold meat preparations Clostridium perfringens vegetative and spore forms, Staphylococcus aureus, Escherichia coli and other Clostridium sp lec(-), as well as Lactobacillus, Bacillus sp. and Salmonella sp. were recovered. For instance Bacillus cereus was present in 6% of the samples.L. monocytogenes, Campylobacter jejuni and Campylobacter coli were rarely present (1–4%) while Yersinia enterocolitica and Campylobacter lari were absent. Differences in the occurrence of S. aureus, Salmonella sp., E. coli and spore forms of C. perfringens in boiled and smoked samples, reflects either the differences in the processing of the foods or could be associated to the extensive handling by the personnel during the purchasing (storage, slicing, wrapping).Antibiotic resistance on specific antibiotics for each pathogen was also studied. A multiresistance antibiotic profile was effective for most bacterial strains, and pronounced resistance profiles were observed for the commonly used antibiotics as ampicillin, penicillin, cephalothin, streptomycin followed by ceftriaxone and gentamycin. Albeit this high observed resistance profile, the tested strains generally conserved their susceptibility to amikacin, aztreonam, chloramphenicol and tylosin conserved an almost absent resistance. Antibiotics commonly used for therapeutic purposes, as well as antibiotics added to feed stuff of animals for increasing animal flesh production should contribute to the extensive spreading of antibiotic resistance in food and the environment.Systematically monitoring of the microbiological quality of cold butchery preparations must be done, in order to preserve food quality, optimizing the processing and elaboration methods of the product and safeguard the public health.     

237例新生儿败血症的病原分布及耐药性分析

目的了解近年本地区新生儿败血症病原学及细菌耐药状况,用以指导临床治疗。方法对2006年5月至2010年4月收治的237例病例的血液进行培养,并对分离的菌株进行鉴定和药敏试验。结果革兰阳性菌为主要病原菌,排名前3位的病原菌分别是:表皮葡萄球菌(48.52%)、人葡萄球菌(16.03%)、凝固酶阴性葡萄球菌(10.13%)。对培养出的革兰阳性菌最敏感的抗生素是万古毒素、阿米卡星,对培养出的革兰阴性菌最敏感的抗生素是丁胺卡那霉素、亚胺培南。结论本地区新生儿血培养病原菌以革兰阳性菌为主,耐药菌株较多,临床医师应根据细菌鉴定及药敏试验选择敏感药物治疗。