Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks

Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential.     

The impact of on-site hospital wastewater treatment on the downstream communal wastewater system in terms of antibiotics and antibiotic resistance genes

This study quantified antibiotic and antibiotic resistance gene (ARG) concentrations in hospital and communal wastewaters as well as the influents and effluents of the receiving urban wastewater treatment plants (UWWTP) in two Dutch cities. In only one city, hospital wastewater was treated on-site using advanced technologies, including membrane bioreactor treatment (MBR), ozonation, granulated activated carbon (GAC) and UV-treatment.On-site hospital wastewater (HWW) treatment reduced gene presence of hospital-related antibiotic resistance genes and antibiotic concentrations in the receiving urban wastewater treatment plant. These findings support the need for on-site treatment of high-risk point sources of antibiotic resistance genes.13 antibiotic resistance genes, Integrase Class 1 and 16S rRNA concentrations were quantified using multiplex quantitative real-time PCR (qPCR) assays and the presence and/or concentration of 711 antibiotics were analyzed.Hospital wastewater contained approximately 25% more antibiotics and gene concentrations between 0.4 log to 1.8-fold higher than communal wastewater (CWW). bla_KPC and vanA could be identified as hospital-related genes and were reduced to under the limit of detection (LOD) during on-site treatment. Advanced on-site treatment removed between 0.5 and 3.6-fold more genes than conventional biological urban wastewater treatment (activated sludge). Advanced on-site treatment was able to eliminate 12 out of 19 detected antibiotics, while urban waste water treatment eliminated up to 1 (out of 21 detected). Different advanced treatment technologies were able to target different pollutants to varying extents, making sequential alignment more effective. MBR treatment was most efficient in antibiotic resistance gene reduction and ozonation in antibiotic reduction.bla_KPC could only be detected in the influent of the urban wastewater treatment plant receiving untreated hospital wastewater. Similarly, vanA was only consistently detected in this treatment plant. These results indicate a positive effect of on-site treatment of hospital wastewater on the communal sewage system.     

常见非发酵革兰阴性杆菌的体外抗菌活性分析

目的　调查常用抗生素对临床常见非发酵革兰阴性杆菌的体外抗菌活性 ,为临床用药提供参考。方法　分析 2 0 0 1年 1月～ 2 0 0 2年 12月本院临床标本中分离出的铜绿假单胞菌、鲍氏不动杆菌和嗜麦芽寡养单胞菌对常用抗生素的耐药性 ,细菌鉴定及药敏试验采用VITEK 6 0全自动微生物鉴定仪。结果　检出非发酵菌6 99株 ,居前 3位的是铜绿假单胞菌 (36 5株 )、鲍氏不动杆菌 (14 1株 )和嗜麦芽寡养单胞菌 (76株 ) ,三者占非发酵菌的 83% ,对哌拉西林 /他唑巴坦的抗菌活性最强 ,敏感率 70 0 % ,其次是头孢他啶、亚胺培南、左氧氟沙星、环丙沙星和替卡西林 /克拉维酸 ,敏感率分别是 5 7 8%、5 5 4 %、5 5 0 %、5 2 0 %和 5 0 0 % ,其余抗生素敏感率都<5 0 0 % ,一代头孢菌素对常见非发酵菌无效 ,嗜麦芽寡养单胞菌对亚胺培南天然耐药。结论　常见非发酵菌是一类多重耐药且耐药性较高的细菌 ,治疗上最好根据药敏选用抗生素 ,并结合其耐药特点联合应用具有协同作用的不同类型抗生素。     

Carotenoid Uptake by Human Triacylglycerol-Rich Lipoproteins from the Green Leafy Vegetable Eruca sativa

Carotenoid absorbability from arugula (Eruca sativa) was estimated from the contents of the triacylglycerol-rich lipoproteins (TRL) of 15 women over a 6 h time interval, yielding an average apparent absorption of 0.27 μmole of β-carotene (5.6 μmole intake), whereas a similar intake of standard β-carotene resulted in the absorption of 0.59 μmole. The corresponding rates for the raw and cooked leaves were 18.2 ± 7 and 22.9 ± 13nmole·L^?1h^?1 (P < 0.05), against 37.1 ± 12nmole·L^?1h^?1 for β-carotene capsules. For lutein, the apparent mean uptakes were 5.6 ± 4 and 6.7 ± 4nmole·L^?1h^?1, for the raw and cooked, respectively. It was concluded that the relative loading of β-carotene onto TRLs is favored over that of lutein and that absorbability of these arugula carotenoids by normal adults is substantial.     

医院非发酵革兰阴性杆菌耐药谱变化分析

目的 了解我院医院感染主要病原菌耐药谱的变化，指导临床合理用药。方法 应用回顾性调查分析方法对我院自l999～2002年上半年临床标本中分离的铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽寡养单胞菌的药敏试验进行统计分折。结果 病原菌仍以革兰阴性杆菌为主，占51．5％；铜绿假单胞菌对阿米卡星、庆大霉素、环丙沙星、头孢哌酮、头孢哌酮／舒巴坦、头孢他啶，鲍曼不动杆菌对阿米卡星、氧氟沙星、氨节西林／舒巴坦、头孢呋辛、头抱吡肟，嗜麦芽寡养单胞菌对氨苄西林／舒巴坦的耐药率已发生显著性变化(P＜0.05)；与未加酶抑制剂抗菌药物相比，几种常见医院感染革兰阴性杆菌对加酶抑制剂抗菌药物耐药率均有不同程度的下降。结论 临床细菌耐药性日趋严重，应在医院开展细菌耐药性监测；指导临床合理应用抗菌药物。     

抗生素耐药性全球治理的发展历程及对中国的启示

目的:归纳总结抗生素耐药性全球治理的发展历程和每个阶段的特点,并为中国参与抗生素耐药性的全球治理提供启示。方法:采用范围综述的方法在ISI Web of Science、Pubmed、Medline等外文期刊数据库中搜索并筛选有关抗生素耐药性全球治理的相关文献,同时收集世界卫生组织、联合国、联合国粮农组织以及世界动物卫生组织等发布的相关资料。结果:抗生素耐药性全球治理的发展历程大致可分为三个阶段:以临床监测为主要策略、由发达国家主导的萌芽阶段;从卫生领域到卫生、农业、环境等多领域共同治理的快速发展阶段;多国家参与并且多领域共同治理的全面覆盖阶段。结论:全世界对于抗生素耐药性全球治理的关注度日益提升,我国应借鉴世界各国采取的有效行动,鼓励多领域协同治理抗生素耐药性问题,以更加积极主动的姿态参与全球治理,并逐步提高社会公众对抗生素耐药性的重视。     

抗菌药物在产科的预防性应用及管理

目的：探讨产科力药物的合理性应用及经济学意义。方法：回顾性调查分析抗菌药物管理前后的临床效果及经济学效果。结果：在加强抗菌药物管理后，正常分娩产妇产后抗生素使用率、抗生素住院日使用率、不合理用药率、联合用药率、围手术期抗生素使用率及经济学指标均优于管理前组；剖宫产产妇不合理用药率、联合用药率及围手术期预防用药等指标优于管理前组。结论：加强产科抗生素管理有助于产科抗生素合理应用及经济学效益的改善。     

Toxicity and Genotoxicity of Three Antimicrobials Commonly Used in Veterinary Medicine

The toxicity of chlortetracycline (CTC), oxytetracycline (OTC) and enrofloxacin (ENF) was tested on two green algal species: the international standard Pseudokirchneriella subcapitata and the native Argentine species Ankistrodesmus fusiformis. All three antibiotics inhibited the algal growth. The most sensitive species was P. subcapitata, for which the EC₅₀ for CTC, OTC and ENF were 1.19?±?0.53, 0.92?±?0.30 and 5.18?±?3.80 mg L^?1, respectively. The EC₅₀ for A. fusiformis, were 3.23?±?0.53, 7.15?±?2.69 and 10.6?±?1.28 mg L^?1, respectively. The genotoxicity of these veterinary antibiotics was also assessed using chromosome aberration (CA) and micronuclei (MN) induction in Allium cepa roots. Three concentrations were tested (0.1, 1 and 10 mg L^?1). Only ENF at 1 and 10 mg L^?1 showed any significant MN induction. These data revealed that CTC, OTC and ENF could cause toxicity on green algae, whereas ENF could cause genotoxicity on A. cepa plants.     

Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review

Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics. Regardless of the growing concerns related to antibiotics in the environment, there are still evident knowledge gaps related to antibiotics, as there is only limited or no ecotoxicological data on many potentially harmful antibiotics.     

Comparative removal of antibiotic resistance genes during chlorination,ozonation, and UV treatment

Efficient treatment methods for the removal of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from drinking water are needed to reduce health risks. However, there is a lack of empirical data on ARB and ARG removal during conventional water disinfection processes. In this study, the removal of ARB and ARGs by three disinfection processes (chlorination, ozonation, and UV treatment) was investigated on a laboratory scale using Escherichia coli and Enterococcus faecium carrying ARGs. Bacterial inactivation was determined by plate count methods, and ARG damage was quantified using real-time PCR. Only for ozone treatment, similar inactivation rates for bacterial cells and ARGs were observed when 1 mg*L^?1 of ozone, with a contact time of 5 min, was used, which resulted in a 5.0 log reduction of bacterial cells and a 4.3–4.6 log reduction of ARGs. For chlorine and UV, inactivation of bacterial cells was observed at lower doses than those needed for the decrease of ARG copy numbers. The use of 0.5 mg*L^?1 free chlorine (30 min contact time) led to a 3.8–5.6 log reduction of the bacterial numbers and to a 0.8–2.8 log reduction of ARGs. Ultraviolet light irradiation with 600 J*m^?2 resulted in a 4.8–5.5 log reduction of bacterial cells, but in a negligible reduction (0–1.0 log) of ARGs. Although UV and chlorine treatments were effective in the inactivation of bacterial cells, incomplete degradation of ARGs was observed. Therefore, plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection process. Our results provide important insights into the fate of ARGs during drinking water disinfection processes.     

抗菌药物在产科的预防性应用及管理

目的 :探讨产科抗菌药物的合理性应用及经济学意义。方法 :回顾性调查分析抗菌药物管理前后的临床效果及经济学效果。结果 :在加强抗菌药物管理后 ,正常分娩产妇产后抗生素使用率、抗生素住院日使用率、不合理用药率、联合用药率、围手术期抗生素使用率及经济学指标均优于管理前组 ;剖宫产产妇不合理用药率、联合用药率及围手术期预防用药等指标优于管理前组。结论 :加强产科抗生素管理有助于产科抗生素合理应用及经济学效益的改善     

Influence of water and food consumption on inadvertent antibiotics intake among general population

Antibiotic entry into the water environment has been of growing concern. However, few investigations have been performed to examine the potential for indirect human exposure to environmental antibiotic residues. We evaluated the contribution of drinking water and major food consumption to inadvertent intake of antibiotic residues among general human population in Korea. We estimated daily human intake of six antibiotics, i.e., sulfamethazine (SMZ), sulfamethoxazole (SMX), sulfathiazole (STZ), trimethoprim (TMP), enrofloxacin (EFX), and roxithromycin (RTM), by measuring the concentrations of the antibiotics and their major metabolites in urine from general population in Korea (n=541). In addition, we measured antibiotics from source water of drinking water as well as in tap water samples, and surveyed water consumption rates among the study population. To assess the contribution of dietary factor, we also surveyed consumption pattern for several major foods which are suspected of antibiotics residue. SMZ, Sulfamethazine-N4-acetyl (SMZ-N4), TMP, EFX, ciprofloxacin (CFX), and RTM were detected up to 448, 6210, 11,900, 6970, 32,400, and 151 pg/ml in the urine samples, respectively. Estimates of daily intake of major antibiotics did not appear to be related with consumption of drinking water although antibiotics were frequently detected in source waters (10-67 ng/l). Consumption of several foods correlated significantly with urinary excretion of several antibiotics. Daily intake estimates of EFX and CFX were associated with consumption of beef, pork, and dairy products; those of SMZ and TMP associated with pork and dairy products; and that of TMP related with raw fish. Daily antibiotics intake estimates however did not exceed the acceptable daily intake levels.     

2007年-2009年山东省生肉中单增李斯特菌的耐药性及分子分型分析

目的:了解山东省生肉中单增李斯特菌的耐药及分子分型特点。方法:药敏实验采用微量肉汤稀释法对15种抗生素进行了耐药检测,分子分型采用脉冲场凝胶电泳(PFGE)的方法。结果:药敏实验显示14.08%的菌株产生耐药,其中对红霉素、左氧氟沙星、复方新诺明的耐药率较高(2.82%);71株菌用PFGE方法分为17个带型,以3型为主。结论:山东省生肉中单增李斯特菌存在较为严重的耐药现象,应加强菌株的耐药性监测;相同来源的单增李斯特菌来自不同的克隆株,但部分菌株有不同程度的相关性;耐药试验和PFGE分型可以相结合,以更好地预防和控制细菌性传染性疾病的发生。     

漯河地区病原菌分布与耐药性分析

目的 了解漯河地区病原菌的分布及常见病原菌耐药性,为临床用药提供科学依据.方法 采用Compact全自动微生物鉴定系统进行鉴定及药敏试验.结果 2007-2010年共分离病原菌5502株,阳性率24.9％;革兰阳性球菌1059株占19.2％,以金黄色葡萄球菌为主,MRSA检出率为48.4％,未发现耐万古霉素菌株;革兰阴性杆菌4345株,占79.0％,其中大肠埃希菌占17.3％、铜绿假单胞菌占13.7％、肺炎克雷伯菌占13.5％、阴沟肠杆菌占5.2％,葡萄球菌属对万古霉素、替考拉宁、呋喃妥因、左氧氟沙星、利福平敏感;对青霉素、克拉霉素、阿奇霉素、红霉素、耐药率＞80.0％.结论 及时监测病原菌变化及耐药趋势,对临床合理用药非常重要.     

贝(甲)壳类海产品中检出致病性气单胞菌的耐药性分析

目的了解源自贝(甲)壳类海产品的致病性气单胞菌体外抗菌药物活性,发现、分析耐药性强弱,为合理使用抗生素提供科学依据。方法药敏试验采用Kirby-Bauer纸片扩散法,药敏评价判断参照2005年版NCCLS微生物药物敏感性试验标准。结果8种1034株致病性气单胞菌对大多抗菌药物敏感,耐药率最高的是氨苄西林抗生素,达91.9%,哌拉西林次之,为77.9%,土霉素和磺胺类也有较高的耐药率,分别为62.4%和56.9%;检出具有产AmpC酶能力的致病性气单胞菌127株,占12.3%,多重耐药性菌株45株,占4.4%。各类致病性气单胞菌对被检测的15种抗菌药物在耐药程度上存在一定差异,以嗜水、温和及豚鼠气单胞菌的耐药性较高。结论试验证实8种致病性气单胞菌对抗菌药物的耐药现象较为普遍,并有产AmpC酶和多重耐药性菌株存在,说明该类细菌具有多渠道获得耐药性的能力,应引起我们的关注。分析其耐药性高的原因可能与水产养殖业在防治疾病中的广泛应用抗菌药物有关,可选择氨基糖甙类、头孢类和氟喹诺酮类等抗菌药物治疗气单胞菌感染。     

2012-2016年山东省抗菌药物消耗抽样调查

目的 分析山东省抗菌药物的消耗和变动趋势,为促进抗菌药物的有效管理与合理应用提供依据。方法 基于山东省39家不同等级医疗机构2012-2016年的药品销售数据,采用解剖学治疗学及化学分类系统(ATC)和限定日剂量值(DDD)方法对抗菌药物进行编码,并对其消耗水平和结构进行计算分析。结果 2012-2016年抗菌药物消耗金额占药品消耗总金额比重从16.23%下降到12.3%。抗菌药物消耗量从2012年的856.09万DDDs缓慢增长到2015年的958.47万DDDs后开始明显下降,至2016年消耗量为754.29万DDDs。注射用抗菌药的消耗由423.21万DDDs降低到281.42万DDDs。各年度中,二三级机构抗菌药物的日均费用均高于基层机构,头孢菌素类消耗量一直居于首位。五年间四环素类、青霉素复方类和碳青霉烯类消耗增长较快。结论 近五年山东省抗菌药物的使用有所改善,其中广谱抗菌药的大量使用和碳青霉烯类消耗量增长较快的趋势应当引起重视,二级及以上机构可作为药品费用控制的关键。     

2013年泰州市健康从业人员携带的沙门氏菌耐药状况以及分子分型研究

目的 了解泰州市健康从业人员携带的沙门氏菌血清型分布、耐药状况以及分子分型特性,为食源性沙门氏菌病的防治提供检测依据。方法 将2013年泰州市健康从业人员分离的58株沙门氏菌进行生化鉴定、血清学分型、药敏试验以及脉冲场凝胶电泳(Pulsed Field Gel Electrophoresis,PFGE)分子分型,并运用BioNumeries软件分析菌株之间的流行病学关系。结果 58株沙门氏菌分为8种血清型,主要以蒙德维的亚沙门氏菌、鼠伤寒沙门氏菌、德尔卑沙门氏菌为主。药敏试验表明,58株沙门氏菌对四环素和萘定酸耐药性最高;多重耐药谱显示耐2种抗生素及以上占39.66%,最高耐10种抗生素。PFGE结果表明,同一血清型的沙门氏菌有多个PFGE带型,相似度大于50.00%,且均有带型100.00%一致的菌株存在。结论 泰州市健康从业人员携带的沙门氏菌耐药谱广,耐药性较强;基因型呈多态分布,但具有流行相关性;各血清型都有100.00%同源菌株,应结合流行病学调查,做好预防控制工作。     

Antibiotic resistance in wastewater: origins,fate, and risks

Antimicrobial resistance is increasing worldwide and threatens our capacity to treat infectious diseases. Recently, special attention has been given to the environment in the cycling of antibiotic resistance from and to humans. In urban areas, wastewater treatment plants represent a critical point of resistance propagation, since the discharge of domestic, hospital, and industrial effluents into municipal collectors mixes together human commensal, pathogenic, and environmental bacteria and high loads of antibiotic residues. Today we observe that wastewater bacteria have a high prevalence of resistance to antibiotics used in the last few decades. In parallel, resistance determinants recently detected in clinical settings are regularly observed in wastewater, suggesting a rapid propagation to the environment. The residues of antimicrobial compounds and some heavy metals play an important role in the propagation of resistance, not only during wastewater treatment but also after the discharge into the environment. Currently, it is not possible to estimate the probability of resistant bacteria or genes reaching humans, but direct transmission seems highly unlikely. However, the contamination of surface water and soil may represent a source of transmission to humans, via the food chain, drinking water, or leisure activities.     

Save antibiotics. What can be done to prevent a forecasted disaster! Suggestions to promote the development of new antibiotics

New antibiotics are needed because of the increasing resistance of bacteria but they will be available in years to come only if drastic changes are implemented in development strategies, evaluation, use, and financing. Over the last decade, various opinions were stated and limited action was undertaken. Optimizing antibiotic use (as the “antibiotic plan” in France) was indispensable, but the process is still on going, and this is only part of the problem. Major questions are recurrently raised such as improvement of development procedures for new antibiotics, optimizing diagnostic methods, innovating financing modalities, or rescue of “old” antibiotics at risk of being withdrawn from the market. The symposium organized in September 2009 by the Swedish EU presidency helped to support previous recommendations. But conclusions remain unspecific. The propositions which are made here, after a work session, have for aim to be more detailed and innovating, even if they can be discussed, or even provocative.     

Nasal carrier rates and antibiotic resistance of Staphylococcus aureus isolates from hospital and non-hospital populations,Addis Ababa

Surgical staff of five different hospitals and university biology students were screened for nasal carriage of Staphylococcus aureus: 32·4% of the surgical staff and 21·6% of the students were carriers. The rate for the hospital staff was significantly higher (χ² = 9·2, P<0·01). The carrier rates among the surgical staff varied between 59·1% for surgeons and 22·7% for other surgical staff.195 S. aureus strains were isolated: 109 from surgical staff and 86 from students. All were tested for their resistance to antibiotics. Resistance to penicillin was 86·2% and 74·4%, respectively, for hospital and non-hospital isolates. Resistance to erythromycin, gentamicin, kanamycin or co-trimoxazole was not detected among the non-hospital isolates. All isolates were sensitive to vancomycin, cephalothin and clindamycin. Over 96% and 88% of hospital and non-hospital isolates, respectively, were resistant to at least one antibiotic. About 45% of the hospital isolates and 2·3% of the non-hospital isolates showed multiple resistance.The rate of multiple resistance among the hospital staff isolates was considered high and indicative of still higher rates among clinical isolates. Further studies are suggested in order to take appropriate measures against bacterial resistance to antibiotics.