Transferable drug resistance in bacteria of coastal canal water and sediment

This study was undertaken to determine the comparative incidence of drug-resistant coliforms and salmonellae in the water and bottom sediments of six coastal canal communities which are used heavily for recreational activities. Of a total of 423 coliforms, 300 fecal coliforms and 100 salmonella isolates examined, 74.9% coliforms, 61.3% fecal coliforms and 71.0% salmonellae were resistant to one or more of the 12 antibiotics tested. Multiple resistance occurred in 48.9% coliforms, 32.7% fecal coliforms and 68.0% salmonella strains. A total of 178 coliforms, 137 fecal coliforms and 51 salmonella isolates were tested for the presence of resistance transfer factors, and 53.9%, 53.3% and 56.9% isolates, respectively, were capable of transferring their resistance patterns to Escherichia coli and/or Salmonella choleraesuis recipient strains. A significantly higher number of drug-resistant bacteria carrying R-factors (R⁺) was found to occur in sediment than in surface water.     

In situ persistence of indicator bacteria in streams polluted with acid mine drainage

Persistence of indicator organisms (total coliforms, fecal coliforms, and fecal streptococci) associated with natural samples of raw sewage was studied following in situ exposure to five aquatic environments. Three of these streams contained significant amounts of acid mine water (AMW) while the other two were relatively uncontaminated. Indicator organisms were rapidly killed upon exposure to the acid mine systems, whereas little reduction in numbers was observed in the uncontaminated streams. Seasonal changes affected survival of indicators as reflected by prolonged persistence at colder in situ water temperatures. The fecal coliform group was most susceptible to the AMW stress, while the fecal streptococci were most persistent. An enrichment technique resulted in substantially enhanced recovery of certain species of sublethally injured survivors of acid stress. Enrichment was particularly beneficial for recovery of AMW-injured fecal coliforms. Relatively little improvement in recovery of fecal streptococci was afforded by the enrichment technique.     

Microbial pollution indicators in Brazilian tropical and subtropical marine surface waters

The specificity of indicators that depend on elevated incubation temperature as a selective factor for their enumeration was questioned because of the possibility of interference from autochthonous microorganisms adapted to high ambient temperatures. Lactose-fermenting cultures isolated from fecal coliform tests of tropical marine surface waters were identified as consisting of about 70% Escherichia coli, and most of the remaining cultures being Klebsiella, Enterobacter or Citrobacter species. This confirmed the taxonomic specificity of fecal coliform tests for these waters. Fecal and total coliforms, fecal streptococcus, heterotrophic bacteria and yeast counts had correlations of above 99% confidence levels with most other microbial and chemical parameters studied. Waters with fecal coliform counts above 1000 per 100 ml had increased incidence of presumptive pathogenic yeasts, Pseudomonas aeruginosa and Salmonella. Our data support the use of coliforms or fecal streptococci as indicators of recent fecal pollution in tropical marine waters and yeast or heterotrophic bacteria counts as complementary indicator methods for these waters.     

Antimicrobial resistance of fecal bacteria in waters of the Seine river watershed (France)

We studied the prevalences of antimicrobial resistance (AR) and multiple antimicrobial resistance (MAR) among the fecal bacteria found in the rivers of a large watershed under strong anthropogenic pressures, the Seine river watershed (France). Two groups of fecal indicator bacteria, Escherichia coli and intestinal enterococci, were tested for their susceptibility to 16 and 10 antimicrobials respectively, using the disk diffusion method. We found that 42% of the 214 E. coli river isolates were AR (resistant to at least one antimicrobial) and 35% were MAR (resistant to at least two antimicrobials). Among the 148 intestinal enterococci isolates from rivers, 83% were AR and 49% were MAR. We also investigated the sources of AR fecal bacteria found in the rivers of the watershed. A total of 715 E. coli isolates and 476 intestinal enterococci isolates were collected in point sources (municipal and hospital wastewaters) and non-point sources (surface runoff and soil leaching waters from agricultural or forest areas). For E. coli, the prevalence of AR differed widely from source to source and ranked in this order: hospital wastewaters (71%) > municipal wastewaters (44%) > agricultural non-point sources (16%) > forest non-point sources (2%). The prevalence of MAR ranked similarly, and the same trend was observed for intestinal enterococci. The AR level of fecal bacteria in the sources was related to their expected exposure level to antimicrobials before their release into the environment. A MAR index was calculated for every source and a good discrimination between them was thus obtained. At the global scale of the Seine river watershed, domestic wastewaters seemed more likely to be the predominant source of the AR fecal bacteria found in the rivers. This was corroborated by the similarity of the MAR indices from river and municipal wastewater isolates for both fecal indicators.     

北京协和医院外科住院患者细菌耐药性监测

【摘要】 目的 了解北京协和医院外科住院患者临床分离细菌分布及对抗菌药物的耐药性。方法 收集2012年1月1日?至2013年12月31日北京协和医院外科住院患者临床分离的3084株非重复细菌，采用纸片扩散法或自动化仪器法进行药敏试验，按美国临床和实验室标准化协会(Clinical and Laboratory Standards Institute，CLSI)2013年版标准判读药敏结果，采用WHONET5.6软件进行数据分析。结果 3084株非重复细菌中10个最常见的细菌依次为鲍曼不动杆菌（14.1％）、大肠埃希菌（12.4％）、铜绿假单胞菌（12.4％）、肺炎克雷伯菌（11.8％）、金黄色葡萄球菌（8.9％）、粪肠球菌（5.4％）、凝固酶阴性葡萄球菌（5.3％）、阴沟肠杆菌（3.7％）、嗜麦芽窄食单胞菌（3.6％）和屎肠球菌（3.2％），其中革兰阴性菌占71.6％（2208株），革兰阳性菌占28.4％（876株）。耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus，MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（methicillin-resistant coagulase negative Staphylococcus，MRCNS）的检出率分别为42.7％（117/274）和77.3％（119/154）。MRS葡萄球菌（MRSA和MRCNS）对β内酰胺类和其他抗菌药物的耐药率明显高于MSS葡萄球菌（MSSA和MSCNS）。MRSA中80.3%菌株对磺胺甲噁唑-甲氧苄啶敏感，MRCNS中95%菌株对利福平敏感。未发现对万古霉素，替考拉宁和利奈唑胺耐药的葡萄球菌。粪肠球菌对大多数抗菌药物的耐药率明显低于屎肠球菌，后者对氯霉素的耐药率仅为4.3%。分别发现1株和5株万古霉素耐药的粪肠球菌和屎肠球菌，根据表型推测为VanA 型耐药；未发现对利奈唑胺耐药的肠球菌。产超广谱β-内酰胺酶（extended spectrum β-lactamases, ESBLs）的大肠埃希菌、克雷伯菌属细菌（肺炎克雷伯菌和产酸克雷伯菌）和奇异变形杆菌的检出率分别为56.7％、23.8％和22.8%。产ESBLs菌株的耐药率明显高于非产ESBLs菌株。肠杆菌科细菌对碳青霉烯类抗菌药物仍高度敏感，总耐药率1.6%～3.3%。泛耐药肺炎克雷伯菌的检出率为0.8%（3/363）。铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为19.5％和15.0％，对阿米卡星的耐药率最低（8.6％）；鲍曼不动杆菌对上述两种抗菌药物的耐药率分别为74.1％和74.0％，对头孢哌酮－舒巴坦和米诺环素的耐药率最低(51.5％和28.9％)。泛耐药鲍曼不动杆菌和铜绿假单胞菌的检出率分别为44.3％和0.8%。结论 定期进行耐药性监测有助于了解细菌耐药性变迁，为临床经验用药提供依据。     

Quantification of fecal coliform inputs to aquatic systems through soil leaching

In order to assess the fecal contamination of rivers in the Seine watershed through soil leaching, 78 small streams located in rural areas were sampled upstream from any wastewater outfall. Culturable fecal coliforms (FC) and beta-D-glucuronidase activity (specific of Escherichia coli) were measured in the samples. Data showed a significant correlation between both estimates of fecal contamination. In the two different areas of the Seine river watershed investigated, most of the small streams were significantly contaminated by fecal bacteria. In general, the streams flowing through areas partly or fully covered with pastures were more contaminated than those flowing through forest and cultivated areas. Rainfall increased the suspended solid content of small streams as well as their fecal contamination, as an important fraction of FC was adsorbed on particles. Calculations showed that, at a large watershed scale, the input of FC in rivers through soil leaching was very low when compared to the input through the discharge of treated domestic wastewater but this could not be true at local scale.     

Incidence of yeasts in coastal sea water of the Attica Peninsula, Greece

Coastal sea water from 15 locations around the Attica peninsula, Greece were collected and analysed for the presence of yeasts on three occasions during 1984. Yeast cell densities ranged from 30 to 1020 CFU 50 ml⁻¹. There was a marked increase in yeast cell densities during the summer months. A total of 30 yeast species were recorded, single sampling stations yielding from 8 to 27 species. Qualitative differences between sites were consistent throughout the sampling period. Potentially pathogenic species, often in high numbers, were recorded from many stations, the most common being Rhodotorula spp, Candida spp, and Torulopsis glabrata. Among isolates of Candida albicans, serotype B occurred significantly more frequently than serotype A.     

Some effects of shoreline cottage development on lake bacteriological water quality

Eighteen cottaged lakes and one uncottaged lake in Southern Ontario, and their inflowing streams were surveyed for bacterial indicators of pollution by membrane filter techniques. Water samples were taken on 5 consecutive days in the spring, summer, and fall of the year. Inputs of fecal indicator bacteria were determined through an analysis of variance. Fecal coliform and fecal streptococcus levels in lakewater varied in a seemingly erratic manner. When the bacterial densities at different points on the lake were examined by an analysis of variance, the locations with significantly higher densities of fecal coliforms and fecal streptococci were most often found along the cottaged shoreline. Total coliform densities did not show this relationship with the cottaged shoreline. In addition, after rainfall, a large increase in numbers of fecal coliforms were found in the cottaged lakes but not in the uncottaged lake. These findings indicated that the cottaged shoreline was a greater source of fecal indicator bacteria than the uncottaged shoreline. However, the highest concentrations of fecal indicator bacteria in these lakes were found in the inflowing streams. The bacteria in these streams arose from stormwater from undeveloped forested watersheds and were probably, therefore, of soil or animal origin.     

Identification of the sources of fecal coliforms in an urban watershed using antibiotic resistance analysis

Bacteria such as fecal coliforms are used as indicators of fecal pollution in natural waters. These bacteria are found in the feces of most wild and domestic animals and thus provide no information as to the source of fecal contamination, yet identification of indicator bacteria sources allows improved risk assessment, remediation, and total daily maximum load (TDML) assessment of environmental waters. This bacterial source tracking study was initiated in order to identify the dominant source(s) of fecal contamination in the urban watershed of Stevenson Creek in Clearwater, Florida. Five sites that represent areas where routine monitoring has previously shown high levels of fecal coliforms were sampled over 7 months. Fecal coliforms were enumerated by membrane filtration, and antibiotic resistance analysis was used to "fingerprint" a subset of randomly selected isolates and statistically match them to fingerprints of fecal coliforms from known sources (the library). A field test of the classification accuracy of the library was carried out by isolating fecal coliforms from the soil and waters surrounding a failing onsite wastewater treatment and disposal system (OSTDS). The vast majority of the isolates were classified into the human category. The major sources of fecal pollution in Stevenson Creek over the course of the study were wild animal, human, and, to a lesser extent, dog. Overall, wild animal feces were identified as the dominant source when fecal coliform levels were high, but when fecal coliform levels were low, the dominant source was identified as human. The results of this study demonstrate that the sources of fecal indicator bacteria within one urban watershed can vary substantially over temporal and spatial distances.     

Behaviour in a river and dam of coliform bacteria with transferable or non-transferable drug resistance

The water in a river and the dam into which it flows was assayed for total coliforms and coliforms with transferable (R⁺) or non-transferable (R^-) resistance to five antimicrobial drugs. The effluent of a sewage works is discharged into the river 10 km upstream of the dam. The ratio of resistant to total coliforms decreased between the sewage works and the dam, but increased between the influent and effluent of the dam. This ratio was higher in the dam effluent than in the river upstream of the sewage works. No difference was detected in the survival of drug-sensitive and known R⁺ and R^- strains in distilled water or saline, or in dialysis bags immersed in the river or dam. Selection of those R⁺ strains resistant to a wide spectrum of drugs occurred in the river and dam. Immersed dialysis bags containing donor and recipient strains were used to demonstrate R factor transfer in the waters concerned. Three out of ten R⁺ strains isolated from the effluent of the dam yielded positive results. These donors were resistant to a wide spectrum of drugs but all determinants were transmitted at a relatively low frequency in the water. One donor had a higher frequency of transfer at 20 than at 37°C. The water pollution significance of these findings is discussed.     

The ecology of "fecal indicator" bacteria commonly found in pulp and paper mill water systems

Coliform bacteria have long been used to indicate fecal contamination of water and thus a health hazard. In this study, the in-mill water and external effluent treatment systems of seven typical Canadian pulp and paper mills were all shown to support the growth of numerous coliforms, especially Klebsiella Spp., Escherichia coli. Enterobacter spp., and Citrobacter spp. In all mills and most sampled locations, klebsiellas were the predominant coliforms. Although all but one of the mills had no sewage input and most disinfected their feed (input) water, all contained the most typical fecal indicator bacterium, E. coli. Many of the mill coliforms were classified as fecal coliforms by standard "MPN" and metabolic tests, but this was shown to be due to their thermotolerance, not their origin. Mill coliforms were shown not to be just simple transients from feedwater or furnish (wood), but to be continuously growing, especially in some of the primary clarifiers. Isolated mill coliforms grew very well on a sterilized raw combined mill effluent. The fecal streptococci (enterococci), alternative indicators of fecal health hazards, were common in all mills in the absence of sewage. Ten strains of E. coli isolated from four mills were all shown to be non-toxigenic strains of harmless serotypes. No salmonellas were found. Therefore, the use of total coliform, fecal coliform, enterococci, or E. coli counts as indicators of fecal contamination, and thus of health hazard in pulp and paper mill effluents or biosolids (sludges) known to be free of fecal input is invalid.     

全国27所医院多重耐药鲍曼不动杆菌及铜绿假单胞菌对12种抗菌药物的敏感性

目的　研究医院感染相关多重耐药鲍曼不动杆菌（multi-drug resistant Acinetobacter baumannii,MDR-AB）及多重耐药铜绿假单胞菌（multi-drug resistant Pseudomonas aeruginosa, MDR-PA）对12种抗菌药物的敏感性。方法　收集2011年8月至2012年7月全国27所教学医院分离的医院感染相关MDR-AB及MDR-PA菌株。所有菌株均分离自有明确感染意义的临床标本，严格排除痰及筛查性拭子。菌株收集后统一在微生物实验室采用微量肉汤稀释法，测定其对12种抗菌药物的最小抑菌浓度（minimum inhibitory concentration，MIC），并同时用CLSI M100-S24及M100-S23/S21鲍曼不动杆菌和铜绿假单胞菌的碳青霉烯类新旧折点进行对比分析。结果　本研究共收集到MDR-AB 664株，未发现全耐药鲍曼不动杆菌；收集到MDR-PA 268株，其中有4株全耐药铜绿假单胞菌。外科病房及ICU病房是多重耐药菌株的主要来源。MDR-AB对黏菌素的敏感率最高，为96.8%；替加环素的敏感率为72.6%，其余药物的敏感率均低于55%。MDR-PA对黏菌素的敏感率仅为72.4%，但对阿米卡星的敏感率（64.2%）明显高于MDR-AB（16.7%）。在CLSI折点改变后，MDR-AB对亚胺培南及美罗培南的敏感率仅分别下降了1.3%和0.6%，但MDR-PA对亚胺培南及美罗培南的敏感率分别下降了5.5%和8.6%。ICU病房来源的MDR-AB及MDR-PA对碳青霉烯酶类药物敏感率都明显低于外科及其他病房。不同地域来源多重耐药菌株的耐药谱有所差异。结论　黏菌素和替加环素对MDR-AB有良好的抗菌活性，黏菌素及阿米卡星对MDR-PA抗菌活性较好。     

2016年北京协和医院细菌耐药性监测

目的了解2016年北京协和医院临床分离细菌对抗菌药物的耐药性。方法收集2016年1月1日至12月31日北京协和医院临床分离的11 721株非重复细菌,采用纸片扩散法或自动化仪器法进行药敏试验,按美国临床实验室标准化协会2016年版标准判读药敏结果,采用WHONET 5.6软件进行数据分析。结果 11 721株非重复细菌中,10种最常见细菌分别为:大肠埃希菌(16.3%)、肺炎克雷伯菌(11.4%)、铜绿假单胞菌(9.3%)、鲍曼不动杆菌(9.0%)、金黄色葡萄球菌(7.4%)、凝固酶阴性葡萄球菌(7.3%)、粪肠球菌(6.1%)、屎肠球菌(3.9%)、B群链球菌(3.4%)、阴沟肠杆菌(3.3%)。其中革兰阴性菌占62.7%,革兰阳性菌占37.3%。耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(methicillin-resistant coagulase-negative Staphylococcus,MRCNS)的检出率分别为27.0%和68.9%。MRSA和MRCNS菌株对β内酰胺类和其他抗菌药物的耐药率明显高于甲氧西林敏感金黄色葡萄球菌(methicillin-susceptible Staphylococcus aureus,MSSA)和甲氧西林敏感凝固酶阴性葡萄球菌(methicillin-susceptive coagulase-negative Staphylococcus,MSCNS)菌株。仍有93.9%的MRSA对磺胺甲噁唑-甲氧苄啶敏感。MRCNS中有85.0%的菌株对利福平敏感。未发现对万古霉素、替考拉宁和利奈唑胺耐药的葡萄球菌。粪肠球菌对大多数抗菌药物(除氯霉素外)的耐药率明显低于屎肠球菌。两者中均有少数万古霉素耐药株。β溶血链球菌对青霉素的敏感率为97.4%。产超广谱β-内酰胺酶的大肠埃希菌、克雷伯菌属(肺炎克雷伯菌和产酸克雷伯菌)和奇异变形杆菌的检出率分别为50.7%(969/1913)、33.9%(488/1439)和32.1%(59/184)。肠杆菌科细菌对碳青霉烯类仍高度敏感,总耐药率≤7.3%。泛耐药肺炎克雷伯菌的检出率为6.5%(87/1331),肺炎克雷伯菌对亚胺培南和美罗培南的耐药率分别为18.0%和16.6%。鲍曼不动杆菌对亚胺培南和美罗培南的耐药率分别为76.7%和74.4%,对替加环素和米诺环素的耐药率最低,分别为9.3%和26.9%。铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为26.3%和18.5%,对阿米卡星的耐药率最低(8.2%)。泛耐药鲍曼不动杆菌和铜绿假单胞菌的检出率分别为24.8%(260/1049)和3.1%(34/1095)。结论肺炎克雷伯菌对碳青霉烯类的耐药率仍较高,给临床抗感染治疗带来极大挑战。     

Antimicrobial resistance of fecal indicators in municipal wastewater treatment plant

Antimicrobial resistance of fecal coliforms (n = 153) and enterococci (n = 199) isolates was investigated in municipal wastewater treatment plant (WWTP) based on activated sludge system. The number of fecal indicators (in influent and effluent as well as in the aeration chamber and in return activated sludge mixture) was determined using selective media. Susceptibility of selected strains was tested against 19 (aminoglycosides, aztreonam, carbapenems, cephalosporins, β-lactam/β-lactamase inhibitors, fluoroquinolones, penicillines, tetracycline and trimethoprim/sulfamethoxazole) and 17 (high-level aminoglycosides, ampicillin, chloramphenicol, erythromycin, fluoroquinolones, glycopeptides, linezolid, lincosamides, nitrofuration, streptogramins, tetracycline) antimicrobial agents respectively. Among enterococci the predominant species were Enterococcus faecium (60.8%) and Enterococcus faecalis (22.1%), while remaining isolates belonged to Enterococcus hirae (12.1%), Enterococcus casseliflavus/gallinarum (4.5%), and Enterococcus durans (0.5%). Resistance to nitrofuration and erythromycin was common among enterococci (53% and 44%, respectively), and followed by resistance to ciprofloxacin (29%) and tetracycline (20%). The resistance phenotypes related to glycopeptides (up to 3.2%) and high-level aminoglycosides (up to 5.4%) were also observed. Most frequently, among Escherichia coli isolates the resistance patterns were found for ampicillin (34%), piperacillin (24%) and tetracycline (23%). Extended-spectrum β-lactamase producing E. coli was detected once, in the aeration chamber. In the study the applied wastewater treatment processes considerably reduced the number of fecal indicators. Nevertheless their number in the WWTP effluent was higher than 10⁴ CFU per 100 ml and periodically contained 90% of bacteria with antimicrobial resistance patterns. The positive selection of isolates with antimicrobial resistance patterns was observed during the treatment processes. Substantial concern should be paid to the isolates resistant to 3 or more chemical classes of antimicrobials (MAR). In treated wastewater MAR E. coli and MAR enterococci constituted respectively 9% and 29% of tested isolates.     

Genetic diversity of Escherichia coli isolates in irrigation water and associated sediments: implications for source tracking

Identifying the sources of fecal contaminants in surface water bodies such as rivers and lakes is of significant importance for environmental quality, food safety and regulatory purposes. Current DNA library-based source tracking approaches rely on the comparison of the genetic relatedness among the fecal contaminants. The objective of this study was to determine the genetic relatedness of Escherichia coli isolated from irrigation water and associated sediments using pulse field gel electrophoresis (PFGE) and to evaluate the genetic stability of the E. coli PFGE patterns. The isolates were obtained over a 4-month period from specific locations within irrigation canals and sediments associated with the Rio Grande River along the Texas-Mexico border. Fifty E. coli isolates were genotyped using PFGE. Different E. coli genotypes were identified among samples collected in 11 different locations. Some isolates obtained over successive months showed similar genotypic patterns. In the laboratory experiment, the PFGE pattern of one E. coli strain changed during survival in irrigation water. The genetic relatedness of this strain changed from >95% to <83% over 8-week survival. These results imply that PFGE is of such extreme resolution that it may be a challenging task to rely solely on a PFGE-based source tracking DNA fingerprint library for large watersheds.     

婴幼儿呼吸道多重耐药菌87株分析

目的探讨婴幼儿呼吸道多重耐药菌菌株分布及耐药特点。方法对2014年1—4月深圳市儿童医院收治的83例呼吸道感染患儿痰（33份）、咽拭子（48份）及肺泡灌洗液（2份）标本培养出87株多重耐药菌菌株的临床资料进行回顾性分析,统计菌株的分布及对药物敏感情况。结果 83例患儿3种标本共分离出多重耐药菌株87株：革兰阳性菌54株（62.07%）,其中耐甲氧西林金黄色葡萄球菌24株、甲氧西林敏感的金黄色葡萄球菌14株、肺炎链球菌16株,革兰阴性菌33株（37.93%）,其中大肠埃希菌产超广谱β-内酰胺酶[ESBLs（＋）]11株、大肠埃希菌不产超广谱β-内酰胺酶[ESBLs（-）]8株、肺炎克雷伯杆菌12株、铜绿假单胞菌2株。48份咽拭子培养分离出48株细菌,33份痰培养分离出37株细菌,2份肺泡灌洗液培养分离出2株细菌。革兰阳性菌敏感药物为万古霉素、利奈唑胺和氧氟沙星等不良反应较大的药物,对青霉素、红霉素和氨苄西林等常用药物耐药;革兰阴性菌敏感药物为头孢他啶、美罗培南及亚胺培南等贵重药物,对氨苄西林、头孢呋辛、头孢唑林等常用药物耐药。分离出69株菌株（79.31%）的66例患儿未使用相应抗生素治疗后均痊愈出院,结合临床考虑定植菌株;分离出18株菌株（20.69%）的17例患儿根据药敏试验使用相应抗生素治疗后痊愈出院,结合临床综合考虑为感染菌株,感染发病率为20.48%。结论婴幼儿呼吸道多重耐药菌株多为革兰阳性菌,以定植菌为主,仅小部分为感染菌株致病;在结合临床考虑定植菌株时应避免滥用抗生素。     

Survival of bacterial indicator organisms and enteric viruses in the Mediterranean coastal waters off Tel-Aviv

Field and laboratory studies were initiated on the die-away kinetics of coliforms and enteric viruses in coastal waters off Tel-Aviv. Samples were taken from the sewage boil located approx. 880 m out to sea and from three main Tel-Aviv beaches designated as sampling stations, ranging 3 km to the north and 2 km to the south. Routine bacteriological tests were made from these stations; in addition, approx. 50% of the samples were also examined for enteroviral content and occasionally, samples were taken from most of the other Tel-Aviv beaches for comparison of bacterial and viral content.The concentrations of total coliforms, fecal coliforms and fecal streptococci were correlated with the concentrations of enteroviruses. In general, the data suggests that the number of enteric bacteria in the sea was reduced relatively more rapidly than that of the enteroviruses, while fecal streptococci displayed a die-away rate similar to that of enteroviruses. The percentage of samples positive for enteroviruses was found to be lower during the summer months of the year than in the remaining months. The concentration of coliforms was also significantly lower during the summer months. This suggests that the decreased microbial level is associated with increased summertime daylight and solar radiation which affect the micro-organisms' die-away rate. About 76% of the positive enteroviral samples were found at beaches with a fecal coliform bacterial level considered safe for bathing beaches.     

2013年北京协和医院细菌耐药性监测

摘要：目的 了解本院2013年临床分离细菌对抗菌药物的耐药性。方法 共收集7236株非重复的细菌，采用纸片扩散法或自动化仪器法进行药敏试验，结果按CLSI2013年版标准判读药敏结果，采用WHONET5.6软件进行数据分析。结果 7236株非重复的细菌中，革兰阴性菌占71.1％，革兰阳性菌占28.9％。耐甲氧西林金黄色葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）的检出率分别为34.9％和67.2％。未发现对万古霉素，替考拉宁和利奈唑胺耐药的葡萄球菌。发现少数万古霉素和替考拉宁耐药的屎肠球菌，未发现对利奈唑胺耐药的肠球菌。产ESBLs的大肠埃希菌，克雷伯菌属细菌（肺炎克雷伯菌和产酸克雷伯菌）和奇异变形杆菌的检出率分别为49.5％，25.4％和22.6％。肠杆菌科细菌对碳青霉烯类抗菌药物仍高度敏感，总耐药率1.1%-2.6%。铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为19.4％和15.6％。鲍曼不动杆菌对上述两种抗菌药物的耐药率分别为70.9％和72.0％。泛耐药鲍曼不动杆菌的检出率为42.9％。结论 细菌耐药性仍是临床重要问题，特别是泛耐药的鲍曼不动杆菌（42.9%，306/714），应采取有效的医院感染控制措施和抗菌药物的合理使用。     

The limitation of the ratio of fecal coliforms to total coliphage as a water pollution index

The fecal coliform populations of raw sewage, sewage lagoon effluent, and river water were determined using the most probable number technique. The total coliphage populations of the three water sources were determined using Escherichia coli B (ATCC 11303-1) host cells. The ratios of fecal coliforms to coliphage in the three water samples were 87:1, 4.2:1, and 0.15:1, respectively. The ratio of fecal coliforms to coliphage in stored raw sewage decreased from 87:1 to about 1:1 within 7 days at 20°C and within 28 days at 4°C. These changing ratios resulted from the greater longevity of the coliphage compared with that of the coliform bacteria. The use of the ratio of fecal coliforms to coliphage is not considered reliable as an index of when a fecal pollution event occurred because the ratio is influenced by prior contamination, presence of sediment, chlorination, and temperature.     

Compositions of first flush and composite storm water runoff in small urban and rural watersheds,north-central Texas

The objective of this study was to evaluate chemical compositions of first flush and composite storm water runoff in four small, mixed land use watersheds in north-central Texas. The watersheds range from urban to rural, all discharging to a local lake providing aquatic habitat, recreation, flood control and drinking water. Automated devices near watershed outlets collected samples from seven storm events, from April 2001 to September 2003. Samples were analyzed for suspended solids, pesticides (diazinon, triazine and chlorpyrifos), nutrients (nitrogen and phosphorus), fecal coliforms and metals. Observed concentrations of most parameters were low relative to drinking water maximum contaminant levels (MCLs) and aquatic life criteria. Fecal coliforms and lead were detected in most samples, with highest lead concentrations in the most developed watershed, likely influenced by building material and automobile traffic. Pesticide concentrations were higher in an initial spring storm event following applications to control weeds and insects. Typical of urban runoff, most ammonia and phosphorus observations exceeded freshwater criteria for streams draining to lakes. Treated wastewater effluent accounted for the highest nitrogen and phosphorus observations. For most constituents, composite concentrations exceeded first flush concentrations, though differences were significant only for fecal coliforms.