Horizontal Distribution and Annual Variations of Fecal Coliform Bacteria in Luoyuan Bay

Fecal Coliform Bacteria （FCB） of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection （ 〈2 cfu/100 mL） to 540 cfu/100 mL in Luoyuan Bay. Values of FCB during August to October were significantly higher than those during January to April during three year period. Monthly changes of FCB values at each year period were mainly due to monthly precipitation. In addition, compared with FCB values in difference sample sites, values of FCB in Bay-heed were significantly higher than those in middle of bay and Bay-mouth, Luoyuan Bay. However, values of FCB in Bay-mouth were significantly less than those in middle of bay. The ratios to the par of FCB in 2003, 2004, and 2005 years were 100%, 98.0%, and 97.9%, respectively. Therefore, we considered that the pollution of FCB of surface marine water in Luoyuan Bay was not serious.

Environmental factors influencing the distribution of total and fecal coliform bacteria in six water storage reservoirs in the Pearl River Delta Region,China

The Pearl River Delta （PRD） is one of the most developed and densely populated regions in China.Quantifying the amount of pathogens in the source of drinking water is important for improving water quality.We collected water samples from six major water storage reservoirs in the PRD region in both wet and dry seasons in 2006.Results showed that external environmental factors,such as precipitation,location,as well as the internal environmental factors,i.e.,physicochemical properties of the water,were closely related with the distribution of coliforms.Seasonally,the coliform bacterial concentrations in wet season were one to two orders of magnitude greater than those in dry season.Spatially,coliform bacterial levels in reservoirs near urban and industrial areas were significantly higher （p 〈 0.05） than those in remote areas.Correlation analyses showed that the levels of coliforms had close relationships with pH,temperature,suspended solid,organic and inorganic nutrients in water.Principal components analysis further demonstrated that total coliforms in the reservoirs were closely related with water physicochemical properties,while fecal coliforms were more associated with external input brought in by seasonal runoff.

Assessing the East Bay of Galveston Bay, Texas for Coliform Bacteria in Recreational Water

The Galveston Bay beach is a widely used recreational area that remains a concern in terms of water quality. There are many factors that contribute to its pollution such as fecal matter entering the bay due to overflow of the sewage system and run offs. Thus, evaluating the water quality for fecal matter and other pollutants is continuously monitored by citizen scientists and research groups throughout the Galveston Bay. The investigation utilizes the colorimetric response of coliform at three test sites along the East Bay of Galveston. Each response is positive for coliform that may indicate the presence of fecal matter. Other scientists have denoted the presence of fecal matter in the Galveston Bay at two sites using enterococci indicator which may be more associated with human fecal matter. The analyses show that the recreational water is likely not a threat since its levels were low. However, the need for analyses based on EPA protocols and standards is necessary to better access water pollution due to fecal matter in the Galveston Bay area.

Changes of composition and antibiotic resistance of fecal coliform bacteria in municipal wastewater treatment plant

The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria(FCB)in a typical wastewater treatment plant(WWTP)were investigated concerning the seasonal changes.Results showed that WWTP could remove the FCB concentration by 3∼5 logs within the effluent of 10^(4)∼10^(5)CFU/L,but the antibiotic resistant rate of FCB species increased significantly after WWTP.The dominant FCB changed from Escherichia coli in the influent(∼73.0%)to Klebsiella pneumoniae in the effluent(∼53.3%)after WWTP,where the Escherichia coli was removed the most,while Klebsiella pneumoniae was the most persistent.The secondary tank removed the most of FCB(by 3∼4 logs)compared to other processes,but increased all the concerned antibiotic resistant rate.The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP.The FCB showed the highest multiple antibiotic resistance(92.9%)in total which even increased to 100%in the effluent.Klebsiella has the highest antibiotic resistant rate in FCB,with a multiple antibiotic resistance rate of 98.4%.These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.

Prevalence and Antimicrobial Susceptibility Status of Gram-Negative and Gram-Positive Bacteria on Handheld Shopping Trolleys and Baskets in Supermarkets in Ndola, Zambia

Background: Supermarkets are a place visited by individuals with different health conditions daily where microbiological contaminants through touch onto fomites such as trolleys and baskets can be passed on to other people hence potentially spreading infectious diseases. This study aimed to investigate the presence of Gram-negative and Gram-positive bacteria on handheld shopping trolleys and baskets and their antimicrobial susceptibility status against commonly used antibiotics in Zambia. Methods: A cross-sectional study was conducted. Trolleys and basket handles were swabbed and standard microbiological methods were used to identify the bacteria and disc diffusion to determine their antimicrobial susceptibility status. Data was collected from December 2021 to April 2022. Data was analysed using IBM Statistical Package for Social Sciences (SPSS) Version 22. Results: Twenty-eight percent of the 200 total samples were found to be culture-positive and predominant isolates were Staphylococcus aureus (17.3%), Pseudomonas species (4.5%), Escherichia coli (2%), Corynebacterium species (2%), Staphylococcus species (1.5%) and Enterobacter aerogenes (0.5%). Staphylococcus aureus showed the most resistance to azithromycin (17%) followed by ciprofloxacin (2.8%), nitrofurantoin (2.8%) and chloramphenicol (2.8%). Escherichia coli showed 100% resistance to amoxicillin, cloxacillin and ampicillin, 75% resistance to ciprofloxacin and the least resistance to azithromycin (25%) while it was susceptible to nitrofurantoin. Staphylococcus species, Corynebacterium species, Enterobacter aerogenes and Pseudomonas species showed no resistance to any antibiotics. Conclusion: The study showed the presence of microorganisms with considerable antimicrobial resistance to antibiotics in Zambia on trolley and basket handles indicating the need for more initiatives to address proper hygiene in public environmental sites for better infection prevention and control.

Nutrient-Induced Growth of Coliform and HPC Bacteria in Drinking-Water Pipes

We conducted a study on a model drinking water distribution system to evaluate the impact of nutrient in the form of sodium acetate on the growth and survival of coliform and heterotrophic plate count (HPC) bacteria for a maximum of 21 days residence time of water in pipes. Our results show that, besides the nutrient added and the absence of any additional source of contamination and additional supply of nutrient, there was significant growth of the above mentioned bacteria in the pipes and bottles for a couple of days, after which the bacterial population began to decrease. The results indicate that the bacteria used the nutrient to grow and multiply until the nutrient was totally consumed and became depleted in the bulk water phase, after which the bacterial population reached a near stationary level and subsequently declined. This suggests the death of some of the bacteria and their dead cells were used by other bacteria for growth and survival. Using a detection limit of 3.3 CFU/100 mL for the coliforms, the study shows that after sometime, no bacteria were found in the water phase of the pipe, however, the biofilm in the pipes still harbored some of the bacteria. The results have revealed that the bacteria also have the tendency to move from the water phase to the biofilm since the latter provides a more suitable environment for bacteria to thrive on and grow, thus prolonging their survival in the system.

Microbial Load (Bacteria, Coliform and Mould Count/Flora) of Some Common Hot Smoked Freshwater Fish Species Using Different Packaging Materials

Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e. 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load). Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 104 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 104, while C. gariepinus slightly increased from (12.4 - 12.6) × 104. After hot smoking, highest TVC of 8.6 × 104 (OMPBC), 8.3 × 104 (SPBC) and 8.2 × 104 (STPBC) were recorded in C. gariepinus among the 9 packag- ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 104), 7.6 × 104 (OMPBO) and 6.6 × 104 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 104 was recorded in M. rume as against 0.2 × 104 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 104. Packaging did not limit the existence of micro-organisms. Six bacteria species (Micrococcus (acidiophilus, luteus), Bacillus (subtilis, cereus, aureus), Staphylococcus aureus, Streptococcus lactis, Proteus (vulgaricus, morganii), Pseudomonas aureginosa) and three fungi species (Aspergillus (niger, tamari), Rhizopusnigricans, fusariumoxysporum) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species.

松花江干流粪大肠菌群时空变化研究

粪大肠菌群普遍存在于人类和温血动物的粪便中,在水环境和水处理过程中与病原体具有相似的稳定性,水质监测中一般选择粪大肠菌群来表征水体微生物安全状况。对2012年-2019年松花江干流开展粪大肠菌群分布特征的研究,结果表明,粪大肠菌群的数量在2.0×10^(2)~2.4×10^(5)MPN/L之间,月达标率69.1%,2012年-2018年达标率呈现上升趋势,2019年略有下降。各断面年际变化规律不一致,总体上2018年和2019年粪大肠菌群数量明显下降。不同水期数量变化规律不同,沿程数量变化呈现“M”型,表现出粪大肠菌群指标受城市生活污水影响明显。存在一定的季节因素影响,自然衰减不明显,人为因素是污染主要原因。2018年后微生物安全基本得到保证,水体的卫生学状况明显改善。

海藻颗粒面膜类化妆品微生物检验结果分析

为全面了解海藻颗粒面膜类化妆品的微生物污染情况,按《化妆品安全技术规范》(2015年版)方法和参考国内外标准自建的探索性检验方法进行检验。结果显示,海藻颗粒面膜的菌落总数不合格率达40.0%,霉菌和酵母菌数不合格率达30.0%,梭状芽孢杆菌问题率达52.0%,洋葱伯克霍尔德菌群问题发现率为2.0%,不合格率及问题率远高于其他类别化妆品。建议有关部门有针对性地加强对该类化妆品的卫生监督,并完善相应标准修订。

食品中菌落总数和大肠菌群测试片法检验效果分析

目的:探究食品中菌落总数与大肠菌群检验方法的差异,选取最佳检验方法,为食品质量检验方法选择提供参考。方法:选择中国工业微生物菌种保藏管理中心样品,采用常规培养基检测和测试片检测两种检测方法对样品进行检验,分析不同检测方法是否存在差异。结果:两种检测方法均能准确检验菌落总数与大肠菌群,均满足质控样品的结果范围要求。结论:食品检验机构及生产企业可结合实际情况选择恰当的检验方法。

水中粪大肠菌群的测定——多管发酵法与酶底物法的比较

采用多管发酵法和酶底物法,同步测定30个平行样品中的粪大肠菌群。比较数据结果表明,2种方法测定的实验结果具有相关性,且在统计学上没有显著差异。多管发酵法虽作为经典的粪大肠菌群检测方法,需要的试剂和器材比较多,分析步骤多,检测周期长,样品检测结果的相对偏差明显高于酶底物法。酶底物法检测周期短,操作方便,对试验环境条件要求低,弥补了多管发酵法的不足能更好满足环境监测要求。

Comparative analysis of bacterial contamination in tap and groundwater: A case study on water quality of Quetta City, an arid zone in Pakistan

Water is an essential element on earth,which provides human a variety of services in domestic use,agriculture,or industries.However,some serious health risks of drinking water are associated with microbial contamination,particularly with fecal matter.Therefore,microbial quality assessment is considered to be a necessary component of water quality assessment.This study investigates microbial contamination of water distributary system around the city by comparing groundwater(GW)and tap water(TW)quality in Quetta city.31 GW samples and 31 TW samples were collected in the study area during the months of September,October,and November.Fecal coliform test was carried out in laboratory and their average total coliform contamination was computed.Results showed that the TW sample were all contaminated by coliform except for Chiltan town,hence are not considered suitable for drinking without any treatment according to WHO drinking water quality standards.The average coliform concentrations were 12 in Quetta main city,11.6 in Jinnah town,5.3 in Satallite town,10 in Shahbaz town and 5 in Brewery town(0/100 mL CFU)and the TW samples from the three towns were even more contaminated with E.coli.Whereas among the GW,average microbial concentrations were 1.8 in Quetta main city,2 in Satallite town,1.4 in Shahbaz town,and 0.4 in Chiltan town(0/100 mL CFU),respectively,which shows that the contamination is occurring within the water distributary pipeline system when the water flows through the pipelines.Moreover,this research will be valuable for researchers and administrative authorities to conduct elaborative studies,and develop new policies to prevent further deterioration of drinking water in the water distribution system by pathogenic microorganisms and ensure safe drinking water to the public of Quetta city.

食品分析中菌落总数和大肠菌群的测定与控制论述

在食品微生物检测中,菌落总数和大肠菌群被视为关键指标,揭示了食品的卫生状况和安全性。本文通过介绍菌落总数与大肠菌群的定义及差异,对其影响因素及测定方法进行分析说明,并提出防治策略,旨在为食品微生物的检测与防治工作提供借鉴。

DISTRIBUTION OF BACTERIA IN SHELLFISH CULTURE AREA AROUND QINGDAO

Bacteria numbers in water of coastal shellfish culture area around Qingdao were examined in April, August and October 1998 respectively. The results showed that the total numbers of heterotrophic and coliform bacteria in waters of the area and the specific geographical area varied with seasons. The highest populations were recorded during summer, i.e. 1 0×10 4～4 5×10 6cell/ml and 3 0×10 0～2 4×10 3cell/100ml, and with average values of 1 61×10 5cell/ml and 1 24×10 2cell/100ml respectively. The second highest populations occurred in autumn, and the lowest were in spring. The numbers of coliform bacteria were relatively low in waters near the mouths of bays and open part of the shellfish culture area, while those in waters near the estuaries of big rivers, wharves, navigation routes or the area in front of downtown areas were much higher than other areas. Single index assessment of the environment quality of shellfish culture was made to indicate that the water sanitary quality in most of these areas are very good, however, some parts were serious polluted by the faeces of warm blood animals. These results provided theoretical reference for the programming and organizing of shellfish culture.

Zinc phosphate-based nanoparticles as a novel antibacterial agent: in vivo study on rats after dietary exposure

Background: Development of new nanomaterials that inhibit or kil bacteria is an important and timely research topic. For example, financial losses due to infectious diseases, such as diarrhea, are a major concern in livestock productions around the world. Antimicrobial nanoparticles(NPs) represent a promising alternative to antibiotics and may lower antibiotic use and consequently spread of antibiotic resistance traits among bacteria, including pathogens.Results: Four formulations of zinc nanoparticles(Zn A, Zn B, Zn C, and Zn D) based on phosphates with spherical(Zn A, Zn B)or irregular(Zn C, Zn D) morphology were prepared. The highest in vitro inhibitory effect of our NPs was observed against Staphylococcus aureus(inhibitory concentration values, IC50, ranged from 0.5 to 1.6 mmol/L), fol owed by Escherichia coli(IC500.8–1.5 mmol/L). In contrast, methicil in resistant S. aureus(IC501.2–4.7 mmol/L) was least affected and this was similar to inhibitory patterns of commercial Zn O-based NPs and Zn O. After the successful in vitro testing, the in vivo study with rats based on dietary supplementation with zinc NPs was conducted. Four groups of rats were treated by 2,000 mg Zn/kg diet of Zn A, Zn B, Zn C, and Zn D, for comparison two groups were supplemented by 2,000 mg Zn/kg diet of Zn O-N and Zn O, and one group(control) was fed only by basal diet. The significantly higher(P < 0.05) Zn level in liver and kidney of al treated groups was found, nevertheless Zn NPs did not greatly influence antioxidant status of rats. However,the total aerobic and coliform bacterial population in rat feces significantly decreased(P < 0.05) in al zinc groups after 30 d of the treatment. Furthermore, when compared to the Zn O group, Zn A and Zn C nanoparticles reduced coliforms significantly more(P < 0.05).Conclusions: Our results demonstrate that phosphate-based zinc nanoparticles have the potential to act as antibiotic agents.

厦门市2020—2022年上半年复用餐饮具安全风险评估分析

目的:了解福建省厦门市复用餐饮具的卫生质量状况。方法:依据GB 14934—2016对辖区内各业态的复用餐饮具随机抽样,通过检测阴离子合成洗涤剂和大肠菌群等指标,对厦门市2020—2022年上半年复用餐饮具的风险项目及风险业态等抽检数据进行分析。结果:复用餐饮具合格率逐年下降,由2020年的91.8%下降至2022年的65.6%,不合格批次抽检场所主要为小吃店和中小型餐馆,其中不合格项目阴离子合成洗涤剂(以十二烷基苯磺酸钠计)问题检出率较大肠菌群更为严重,约占60%。结论:厦门市复用餐饮具存在一定的食品安全隐患,需持续加强监督管理,以维护食品安全“全域全年”稳定。

温度、时间对不同方法检测地下水中总大肠菌群的影响

分别以温度和时间为变量,比较了滤膜法、酶底物法检测地下水中总大肠菌群的数量。研究表明,2种方法的检测结果随温度变化趋势基本一致,在35、36、37℃时,大肠菌群生长最快,3个温度下的检测结果基本无差异(P<0.05),而与28、32、40℃下的检测结果相比差异明显。滤膜法和酶底物法的培养时间在22、24、28 h时总大肠菌群基本无差异(P<0.05),而16、18、20、32 h的总大肠菌群数差异明显。因此为保证实验数据真实准确,2种检测方法都应严格控制培养温度和时间。培养温度为36±1℃,培养时间为22~28 h。

城乡生活饮用水水质检测结果分析

目的:探究罗定市城乡生活饮用水的水质情况。方法:按《生活饮用水标准检验方法》(GB/T 5750.2—2006)规定,从2020年5月下旬到2022年11月初,收集罗定市城镇与乡镇的出厂水、末梢水共842份进行检测,分析该地区的城乡生活饮用水水质。结果:2020—2022年城乡生活饮用水总合格率为78.03%(657/842),2020年城乡生活饮用水合格率为90.38%(216/239),2021年城乡生活饮用水合格率为68.09%(224/329),2022年城乡生活饮用水合格率为79.20%(217/274);城镇生活饮用水合格率为92.14%(129/140),乡镇生活饮用水合格率为75.21%(528/702);出厂水的合格率为80.71%(251/311),末梢水的合格率为76.46%(406/531)。2021年罗定市城乡生活饮用水的水质检测合格率低于2020年与2022年,城镇的水质检测合格率高于乡镇,差异有统计学意义(P<0.05);不同水样类型的水质检测合格率相当,差异无统计学意义(P>0.05);2020—2022年,微生物指标不合格率最为严重,其中细菌总数不合格率为5.70%,总大肠菌群不合格率为6.77%。结论:罗定市城乡生活饮用水合格率较低,微生物指标超标严重,需给予高度重视。

基于整体法的食品中大肠菌群测量不确定度评定

本文采用平板计数法,以人工污染大肠菌群羊肉样品为例,测量了不确定度,并评定了数据的离散型。结果表明,试验不确定度来源为样品制备的均质性、标准菌株的接种量波动、培养基制备与pH调节的精确度、恒温培养条件的一致性、菌落数计数的人为误差,以及仪器的校准误差。

河南省市场销售冷冻鸡胸肉理化指标及微生物污染情况抽样调查

为了解河南省市场销售冷冻鸡胸肉的品质及卫生状况,从农贸市场和规模化超市抽取冷冻保存40~110d的鸡胸肉样品126份,进行沙门氏菌、大肠菌群、致泻性大肠埃希氏菌、菌落总数以及挥发性盐基氮检验。结果显示:共检出沙门氏菌阳性样品8份,阳性率为6.3%;大肠菌群阳性样品111份,阳性率为88.1%;未检出致泻性大肠埃希氏菌阳性样品;菌落总数范围为1.1×10^(4)~4.0×10^(5)CFU/g,挥发性盐基氮含量范围为9.6~13.4 mg/100 g,均未超出国家标准和相关规定。结果表明,河南省市场销售冷冻鸡胸肉在保存期110 d内品质良好,但大肠菌群污染较为普遍,也存在沙门氏菌污染风险。提示鸡屠宰、加工企业应严格控制微生物污染,消费者应购买距生产日期较近的冷冻鸡胸肉产品,加工过程中注意防护,且须彻底煮熟食用。