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1.
J Environ Sci (China) ; 146: 241-250, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38969452

RESUMO

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 104∼105 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.


Assuntos
Escherichia coli , Fezes , Eliminação de Resíduos Líquidos , Águas Residuárias , Águas Residuárias/microbiologia , Eliminação de Resíduos Líquidos/métodos , Fezes/microbiologia , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Farmacorresistência Bacteriana , Microbiologia da Água , Klebsiella pneumoniae/efeitos dos fármacos
2.
J Water Health ; 22(6): 1111-1124, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38935461

RESUMO

Diarrhoea is one of the major waterborne diseases spread through the faecal-oral route causing over 10 million cases and over 1,000 deaths per year in India. This study critically evaluates the interlinkage between bacteriological water quality, i.e. faecal coliforms and diarrhoea cases for the three pre-pandemic years 2017, 2018 and 2019 based on multiple sources. With around 17% of households tap water connectivity as of August 2019, the majority of the Indian population depends on raw groundwater (GW) and surface water sources. For this, faecal coliform (FC) levels in surface and GW have been mapped at district levels using data from India's National Water Quality Monitoring Programme. Health Management Information System's data on diarrhoea have been used to understand the monthly and district-wise variation of diarrhoea. The trends of FC, diarrhoea inpatient cases, and diarrhoea inpatient rates have been discussed. The analysis showed issues associated with the reliability and usefulness of these datasets with 43% of total India districts with no reported FC values for the study period. This study reveals a clear gap in the interlinkage between diarrhoea and bacteriological water quality with the unavailability of granular water quality data as a major challenge.


Assuntos
Diarreia , Água Potável , Fezes , Microbiologia da Água , Diarreia/microbiologia , Diarreia/epidemiologia , Índia/epidemiologia , Água Potável/microbiologia , Humanos , Fezes/microbiologia , Qualidade da Água , Enterobacteriaceae/isolamento & purificação , Abastecimento de Água
3.
Poult Sci ; 103(7): 103847, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38776858

RESUMO

Organic acids are applied to poultry carcasses during processing to reduce foodborne pathogens and spoilage microorganisms. Scald water surfactant agents employed to improve feather removal may enhance the efficacy of organic acids during processing. This study investigated the effects of concurrent application of a scald water surfactant and organic acid dip on microbial contamination of carcasses processed in a small-scale production model. Broilers were reared in litter floor pens to 47 d of age and slaughtered using standard practices. Carcasses were scalded in either control or surfactant scald water initially and dipped in either a 2% organic acid blend or water after feather removal to complete a 2 × 2 factorial arrangement with n = 15 carcasses per treatment group. The commercially available scald water additive was a slightly alkaline surfactant solution labelled as a feather removal aid. The organic acid dip consisting of lactic and citric acid was maintained at pH of 2.5. Approximately 10 g of neck skin was collected 1-min postdipping and placed in buffered peptone water with an added neutralizing agent, sodium thiosulfate. Serial dilutions were performed to determine general coliform (GC), E. coli (EC), and aerobic plate (APC) counts as CFU per gram of skin sample. A significant 0.61, 0.76, and 1.6 log reduction of GC, EC, and APC, respectively, was attributed to use of the organic acid carcass dip (P ≤ 0.01). There were no significant differences in carcass microbial reduction due to surfactant scald water alone. A 0.69, 0.73 (P ≤ 0.05), and 1.96 log reduction of GC, EC, and APC, respectively, was observed in surfactant-scalded, acid-dipped carcasses compared to water-scalded, water-dipped control groups. These data demonstrated that a surfactant scald water additive and an organic acid carcass dip can have beneficial effects of microbial reduction when employed simultaneously during broiler processing.


Assuntos
Galinhas , Manipulação de Alimentos , Microbiologia de Alimentos , Tensoativos , Animais , Tensoativos/farmacologia , Tensoativos/administração & dosagem , Manipulação de Alimentos/métodos , Carne/análise , Carne/microbiologia , Ácido Cítrico/farmacologia , Ácido Cítrico/administração & dosagem , Matadouros , Ácido Láctico/farmacologia
4.
Environ Geochem Health ; 46(6): 209, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38814487

RESUMO

A comprehensive understanding of water quality is essential for assessing the complex relationship between surface water and sources of pollution. Primarily, surface water pollution is linked to human and animal waste discharges. This study aimed to investigate the physico-chemical characteristics of drinking water under both dry and wet conditions, assess the extent of bacterial contamination in samples collected from various locations in District Shangla, and evaluate potential health risks associated with consuming contaminated water within local communities. For this purpose, 120 groundwater and surface water samples were randomly collected from various sources such as storage tanks, user sites, streams, ponds and rivers in the study area. The results revealed that in Bisham, lakes had the highest fecal coliform levels among seven tested sources, followed by protected wells, reservoirs, downstream sources, springs, rivers, and ditches; while in Alpuri, nearly 80% of samples from five sources contained fecal coliform bacteria. Similarly, it was observed that the turbidity level, total dissolved solids, electrical conductivity, biological oxygen demand, and dissolved oxygen in the surface drinking water sources of Bisham were significantly higher than those in the surface drinking water sources of Alpuri. Furthermore, the results showed that in the Alpuri region, 14% of the population suffers from dysentery, 27% from diarrhea, 22% from cholera, 13% from hepatitis A, and 16% and 8% from typhoid and kidney problems, respectively, while in the Bisham area, 24% of residents are affected by diarrhea, 17% by cholera and typhoid, 15% by hepatitis A, 14% by dysentery, and 13% by kidney problems. These findings underscore the urgent need for improved water quality management practices and public health interventions to mitigate the risks associated with contaminated drinking water. It is recommended to implement regular water quality monitoring programs, enhance sanitation infrastructure, and raise awareness among local communities about the importance of safe drinking water practices to safeguard public health.


Assuntos
Água Potável , Microbiologia da Água , Qualidade da Água , Paquistão , Água Potável/microbiologia , Água Potável/química , Humanos , Monitoramento Ambiental/métodos , Água Subterrânea/microbiologia , Água Subterrânea/química , Fezes/microbiologia , Bactérias/isolamento & purificação
5.
Heliyon ; 10(7): e27924, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38586413

RESUMO

Open-surfaced water sources have been used to irrigate vegetable farms in cities. Open-surface water often contains unmonitored concentrations of health-threatening contaminants that pose health risks, especially when used to produce vegetables for human consumption. However, information on levels of heavy metals and faecal coliform bacteria in such vegetables in selected sites, especially in Greater Accra Metropolitan Area (GAMA) of Ghana is rare. This study examines the levels of heavy metals and faecal coliform in two vegetables-lettuce and bell pepper - that were cultivated using open-surface wastewater from drains and constructed reservoirs at different locations of the GAMA. Using concurrent mixed methods, questionnaires were administered to 67 vegetable farmers, followed by the collection of vegetable samples from three urban farm sites, Haatso and Dzorwulu and Weija irrigation scheme site (WISS) for laboratory analysis. The concentrations of Lead (Pb), Mercury (Hg) and Cadmium (Cd) were determined using atomic absorption spectroscopy after microwave digestion of the vegetables while total faecal coliform was quantified using MacConkey-Endo broth method. The results from all three sites showed that the concentrations of Cd (=0.001 µg/mg) and Pb (=0.005 µg/mg) in lettuce were within the World Health Organization's (WHO) permissible levels. However, the Hg (≥0.309 µg/mg) and faecal coliform (>5 count/100 ml) in the vegetables from all three sites exceeded the WHO permissible limits. Therefore, consumers of vegetables from such urban farms are exposed to health risks associated with Hg and faecal coliforms. There is the need to intensify education on the health risks of consuming vegetables produced from open-surface water sources from the observed sites. The enforcement of existing phytosanitary standards to enhance food safety and the quality of urban vegetables is also recommended.

6.
Environ Monit Assess ; 196(5): 483, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38683410

RESUMO

This study rigorously assesses the physicochemical, heavy metal concentrations, and bacteriological parameters of celery and its irrigation water across three rural areas of Sulaymaniyah city, Iraq. The investigation revealed that irrigation water's pH ranged significantly from 6.9 to 8.9. Notably, phosphate concentrations (PO43-) exceeded permissible levels in Tanjaro and Kanaswra across all seasons, with the highest recorded concentration being 10.4 mg L-1 during autumn in Kanaswra. Conversely, sulfate (SO42-) and sodium (Na+) concentrations remained within standard limits, with SO42- peaking at 115.1 mg L-1 in Tanjaro during summer. Celery samples reflected high Na+ concentrations in some seasons, with values exceeding 570 mg·kg in Kanaswra during summer. Heavy metal analysis indicated remarkably low levels in irrigation water, yet celery samples from Tanjaro and Aziz Awa exhibited Pb concentrations above the safety threshold of 0.3 mg·kg in all seasons. Furthermore, bacterial contamination, including total aerobic count and coliform in both water and celery, surpassed standard limits, highlighting significant health risks. This study underscores the imperative need for stringent water treatment processes to mitigate contamination and safeguard agricultural productivity and human health.


Assuntos
Irrigação Agrícola , Monitoramento Ambiental , Metais Pesados , Poluentes Químicos da Água , Iraque , Metais Pesados/análise , Poluentes Químicos da Água/análise , Apium , Cidades , Microbiologia da Água
7.
Mar Pollut Bull ; 201: 116189, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38430680

RESUMO

The Negombo Lagoon is a coastal lagoon influenced by local communities that introduce waste into its ecosystem. This study examined seven sewage entry points, out of which five sites were chosen for oyster sampling based on availability. Physicochemical and microbiological parameters of water (measured in triplicate at each site, n = 84) and oyster samples (total length, TL > 6 cm, n = 30) were assessed. Variation in regional coliform contamination was analyzed employing a one-way analysis of variance (ANOVA). Results indicated that the northern part of the lagoon exceeded recommended coliform thresholds for swimming (total coliform concentration (TCC) < 126 most probable number (MPN)) and seafood consumption (TCC < 100 MPN/g), indicating the presence of Escherichia coli. Water quality indices affirmed fecal pollution, except in the southern part of the lagoon. Furthermore, the study found high oyster consumption (76.7 %), elucidating that oysters from the northern part of Negombo Lagoon pose health risks.


Assuntos
Crassostrea , Humanos , Animais , Sri Lanka , Ecossistema , Natação , Alimentos Marinhos
8.
Int J Food Microbiol ; 416: 110665, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38457887

RESUMO

Romaine lettuce in the U.S. is primarily grown in California or Arizona and either processed near the growing regions (source processing) or transported long distance for processing in facilities serving distant markets (forward processing). Recurring outbreaks of Escherichia coli O157:H7 implicating romaine lettuce in recent years, which sometimes exhibited patterns of case clustering in Northeast and Midwest, have raised industry concerns over the potential impact of forward processing on romaine lettuce food safety and quality. In this study, freshly harvested romaine lettuce from a commercial field destined for both forward and source processing channels was tracked from farm to processing facility in two separate trials. Whole-head romaine lettuce and packaged fresh-cut products were collected from both forward and source facilities for microbiological and product quality analyses. High-throughput amplicon sequencing targeting16S rRNA gene was performed to describe shifts in lettuce microbiota. Total aerobic bacteria and coliform counts on whole-head lettuce and on fresh-cut lettuce at different storage times were significantly (p < 0.05) higher for those from the forward processing facility than those from the source processing facility. Microbiota on whole-head lettuce and on fresh-cut lettuce showed differential shifting after lettuce being subjected to source or forward processing, and after product storage. Consistent with the length of pre-processing delays between harvest and processing, the lettuce quality scores of source-processed romaine lettuce, especially at late stages of 2-week storage, was significantly higher than of forward-processed product (p < 0.05).


Assuntos
Escherichia coli O157 , Microbiota , Microbiologia de Alimentos , Lactuca , Escherichia coli O157/genética , Inocuidade dos Alimentos , Contagem de Colônia Microbiana , Manipulação de Alimentos , Contaminação de Alimentos/análise
9.
Food Sci Technol Int ; 30(3): 282-289, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36632027

RESUMO

In recent years, ultraviolet and ultrasound treatments are gaining attraction as promising green decontamination technologies to ensure microbial safety in food industry. Decontamination by ultraviolet light is a physical process defined by the transfer of electromagnetic energy from a light source to an organism's cellular material and depended on the emission of radiation in the ultraviolet region (100-400 nm), specifically the UV-C region (200-280 nm) which has been demonstrated to be germicidal. Ultrasound technology is defined as sound waves with high and low frequency beyond the limit of human hearing and shows a decontamination effect that occurs as a consequence of cavitation at high power (low frequency) in general. In the present study, it was aimed to determine the effectiveness of ultraviolet light (254 nm, 10 min) and high frequency ultrasound techniques (40 kHz, 10 min) in reducing total aerobic mesophilic bacteria, yeast and mold, Esherichia coli/coliform and Salmonella spp. on the equipment surfaces used in the catering facility. For this purpose, the equipment (cutting knife, meat grinder knife, knife sharpener, cut-proof glove) used in the meat preparation department of catering facility were selected for the treatments. According to the results, appreciable reductions were achieved in total aerobic mesophilic bacterial counts of the ultraviolet treated samples (maximum difference 2.61 log cfu/cm2) and the ultrasound treated samples (maximum difference 4.07 log cfu/cm2). After ultraviolet treatment, Salmonella spp. were totally inhibited on the contaminated surfaces. Furthermore, Escherichia coli/coliform was not detected in the samples after both treatments whereas it was detected before the treatments. It has been concluded that the techniques are effective in reducing microbiological load and also ultraviolet treatment is effective on pathogenic microorganisms on food contact surfaces. As a result, the ultraviolet and ultrasound techniques are effective treatments for equipment disinfection in the catering sector and can be used industrially as it gives successful results.


Assuntos
Desinfecção , Raios Ultravioleta , Humanos , Desinfecção/métodos , Contagem de Colônia Microbiana , Carne/microbiologia , Carga Bacteriana , Indústria de Processamento de Alimentos , Escherichia coli , Bactérias Aeróbias , Microbiologia de Alimentos
10.
Sci Total Environ ; 912: 169506, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123084

RESUMO

This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).


Assuntos
Antibacterianos , Ozônio , Ozônio/química , Esgotos/química , Tetraciclina , Bactérias
11.
Environ Health Insights ; 17: 11786302231216864, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38089526

RESUMO

We investigated the bacteriological quality of drinking water and antimicrobial resistance of bacterial isolates in food and drinking establishments in Shashemane town, Ethiopia. A cross-sectional study was conducted from July to August 2022. One hundred water samples were collected from the tap water and storage containers of 50 selected establishments. All the collected samples were analyzed for bacteriological and antimicrobial susceptibility tests using standard procedures. The study found approximately 80% of water samples from the tap and all water samples (100%) from storage containers were contaminated with total coliforms. E. coli was detected in 20% and 26% of water samples from the tap and storage containers, respectively. A total of 68 bacterial isolates were identified, including E. coli (33.8%), Staphylococcus (25%), Salmonella (17.64%), Klebsiella (11.76%), Shigella (10.29%), and Pseudomonas (1.4%). The highest resistance by the isolates was observed against ampicillin (96%), followed by amoxicillin (94%), cotrimoxazole (76.8%), chloramphenicol (36%), gentamycin (23%), ciprofloxacin (23%), and ceftriaxone (12%). The study concluded that drinking water in food and drinking establishments was found vulnerable to microbiological contamination and it is a health risk to consumers. The level of contamination in stored water was found higher than tap water. In addition, antimicrobial-resistant bacteria such as E. coli, Salmonella, Shigella, Klebsiella, and Staphylococcus aureus were detected in both tap water and stored water. Therefore, awareness should be given to food handlers and owners of the establishments on hygienic water handling practices by the regulatory bodies of Shashemane town and stakeholders.

12.
J Microorg Control ; 28(3): 109-116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37866892

RESUMO

Shredded cabbage treated with either tap water or electrolyzed water was stored in an active modified atmosphere packaging (MAP) of 10% CO2 for 5 d at 10℃, 7 d at 5℃, and 8 d at 1℃ to evaluate the occurrence and viability of sublethally injured coliform bacteria. The CO2 and O2 concentrations in the packages approached an equilibrium of 10% CO2 and 10% O2 during storage at all temperatures tested. Coliforms in shredded cabbage increased during storage at all three temperatures, with the increase being greater at 10℃. Sublethal injury at 65% to 69% for the coliforms was detected only on cabbage samples treated with electrolyzed water and stored at 5℃ for 4 and 7 d. Enterobacter cloacae was one of the injured species of coliform bacteria in shredded cabbage. Shredded cabbage was inoculated with chlorine-injured Escherichia coli O157:H7 and stored at 5℃ for 6 d in an active MAP of 10% CO2. Counts of E. coli O157:H7 remained almost constant during storage, and injured E. coli O157:H7 ranging from 50% to 70% were found on shredded cabbage throughout the storage period. These results indicate that sublethally injured indicator and pathogenic bacteria would be found on fresh-cut cabbage in the realistic MAP storage at 5℃.


Assuntos
Brassica , Brassica/microbiologia , Dióxido de Carbono/farmacologia , Microbiologia de Alimentos , Contagem de Colônia Microbiana , Escherichia coli , Embalagem de Alimentos/métodos , Água
13.
Environ Sci Pollut Res Int ; 30(47): 103836-103850, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37691063

RESUMO

The Edwards Aquifer is the primary water resource for over 2 million people in Texas and faces challenges including fecal contamination of water recharging the aquifer, while effectiveness of best management practices (BMPs) such as detention basins in mitigating fecal pollution remains poorly understood. For this study, the inlet and outlet of a detention basin overlying the aquifer's recharge zone were sampled following storm events using automated samplers. Microbial source tracking and culture-based methods were used to determine the occurrence and removal of fecal genetic markers and fecal coliform bacteria in collected water samples. Markers included E. coli (EC23S857), Enterococcus (Entero1), human (HF183), canine (BacCan), and bird (GFD). Fecal coliforms, EC23S857, and Entero1 were detected following each storm event. GFD was the most frequent host-associated marker detected (91% of samples), followed by BacCan (46%), and HF183 (17%). Wilcoxon signed rank tests indicated significantly lower outlet concentrations for fecal coliforms, EC23S857, and Entero1, but not for HF183, GFD, and BacCan. Higher GFD and BacCan outlet concentrations may be due to factors independent of basin design, such as the non-point source nature of bird fecal contamination and domestic dog care practices in neighborhoods contributing to the basin. Mann-Whitney tests showed marker concentrations were not significantly higher during instances of fecal coliform water quality criterion exceedance, except for E. coli, and that fecal coliform concentrations were not significantly different based on marker detection. Overall, results suggest that the detention basin is effective in attenuating fecal contamination associated with fecal coliforms and the general markers, but not for host-associated markers. Consequently, management efforts should focus on mitigating dog and bird-associated fecal pollution in the study region.


Assuntos
Água Subterrânea , Poluição da Água , Animais , Cães , Humanos , Poluição da Água/análise , Monitoramento Ambiental/métodos , Texas , Escherichia coli , Microbiologia da Água , Bactérias/genética , Enterococcus , Fezes/microbiologia , Aves
14.
Water Res ; 244: 120494, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37611356

RESUMO

Microbial water quality is routinely examined using the fecal indicator bacteria Escherichia coli, coliform bacteria and enterococci. Several practical cases in German drinking water distribution systems indicated invertebrates such as insects or gastropods as a source for the microbiological deterioration. Therefore, we examined three genera of Gastropoda (Arion, Helix and Cepaea) for the presence of fecal indictor bacteria in excreta using standard methods. Enterococci and coliform bacteria were detected in high concentrations (mean values of 1.5 × 106 and 6.3 × 106 per gram feces, respectively). E. coli was also detected, still specification revealed that what was assigned by standard ISO-methods to be E. coli was indeed a novel species of Buttiauxella, exhibiting ß-D-glucuronidase activity, thus, explaining the false-positive results. Microbiome analyses confirmed the cultural results. Enterobacteriaceae were dominant in the samples, yet only very few sequences could be assigned to Escherichia. Our study suggests, that enterococci and coliform bacteria are an integral component in the gastropod microbiome, whereas E. coli might be derived from other sources with gastropods being a vector. The results further indicate, that the current concept of fecal indicator bacteria needs to be extended, as not only humans and homeothermic animals could be a source for fecal indictor bacteria, but also gastropods need to be taken into consideration.


Assuntos
Água Potável , Escherichia coli , Animais , Humanos , Microbiologia da Água , Bactérias , Enterobacteriaceae , Enterococcus , Fezes/microbiologia , Monitoramento Ambiental
15.
Mar Pollut Bull ; 193: 115220, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37390625

RESUMO

Modeling fecal contamination in water bodies is of importance for microbiological risk assessment and management. This study investigated the transport of fecal coliform (e.g., up to 2.1 × 106 CFU/100 ml at the Zhongshan Bridge due to the main point source from the Xinhai Bridge) in the Danshuei River estuarine system, Taiwan with the main focus on assessing model uncertainty due to three relevant parameters for the microbial decay process. First, a 3D hydrodynamic-fecal coliform model (i.e., SCHISM-FC) was developed and rigorously validated against the available data of water level, velocity, salinity, suspended sediment and fecal coliform measured in 2019. Subsequently, the variation ranges of decay reaction parameters were considered from several previous studies and properly determined using the Monte Carlo simulations. Our analysis showed that the constant ratio of solar radiation (α) as well as the settling velocity (vs) had the normally-distributed variations while the attachment fraction of fecal coliform bacteria (Fp) was best fitted by the Weibull distribution. The modeled fecal coliform concentrations near the upstream (or downstream) stations were less sensitive to those parameter variations (see the smallest width of confidence interval about 1660 CFU/100 ml at the Zhongzheng Bridge station) due to the dominant effects of inflow discharge (or tides). On the other hand, for the middle parts of Danshuei River where complicated hydrodynamic circulation and decay reaction occurred, the variations of parameters led to much larger uncertainty in modeled fecal coliform concentration (see a wider confidence interval about 117,000 CFU/100 ml at the Bailing Bridge station). Overall, more detailed information revealed in this study would be helpful while the environmental authority needs to develop a proper strategy for water quality assessment and management. Owing to the uncertain decay parameters, for instance, the modeled fecal coliform impacts at Bailing Bridge over the study period showed a 25 % difference between the lowest and highest concentrations at several moments. For the detection of pollution occurrence, the highest to lowest probabilities for a required fecal coliform concentration (e.g., 260,000 CFU/100 ml over the environmental regulation) at Bailing Bridge was possibly greater than three.


Assuntos
Monitoramento Ambiental , Hidrodinâmica , Monitoramento Ambiental/métodos , Incerteza , Enterobacteriaceae , Rios/microbiologia , Bactérias Gram-Negativas , Fezes/microbiologia , Microbiologia da Água
16.
Front Public Health ; 11: 1199314, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37361152

RESUMO

Objective: More than half of the 700 million people worldwide who lack access to a safe water supply live in sub-Saharan Africa, including Ethiopia. Globally, approximately 2 billion people use drinking water sources that are contaminated with fecal matter. However, little is known about the relationship between fecal coliforms and determinants in drinking water. Therefore, the objective of this study was to investigate the potential for contamination of drinking water and its associated factors in households with children under 5 years of age in Dessie Zuria district in northeastern Ethiopia. Methods: The water laboratory was conducted based on the American Public Health Association guidelines for water and wastewater assessment using a membrane filtration technique. A structured and pre-tested questionnaire was used to identify factors associated with the potential for contamination of drinking water in 412 selected households. A binary logistic regression analysis was performed to determine the factors associated with the presence or absence of fecal coliforms in drinking water, with a 95% confidence interval (CI) and a value of p ≤ 0.05. The overall goodness of the model was tested using the Hosmer-Lemeshow test, and the model was fit. Results: A total of 241 (58.5%) households relied on unimproved water supply sources. In addition, approximately two-thirds 272 (66.0%) of the household water samples were positive for fecal coliform bacteria. Water storage duration ≥3 days (AOR = 4.632; 95% CI: 1.529-14.034), dipping method of water withdrawal from a water storage tank (AOR = 4.377; 95% CI: 1.382-7.171), uncovered water storage tank at control (AOR = 5.700; 95% CI: 2.017-31.189), lack of home-based water treatment (AOR = 4.822; 95% CI: 1.730-13.442), and unsafe household liquid waste disposal methods (AOR = 3.066; 95% CI: 1.706-8.735) were factors significantly associated with the presence of fecal contamination in drinking water. Conclusion: Fecal contamination of water was high. The duration of water storage, the method of water withdrawal from the storage container, covering of the water storage container, the presence of home-based water treatment, and the method of liquid waste disposal were factors for fecal contamination in drinking water. Therefore, health professionals should continuously educate the public on proper water use and water quality assessment.


Assuntos
Água Potável , Humanos , Criança , Pré-Escolar , Etiópia , População Rural , Abastecimento de Água , Inquéritos e Questionários
17.
Heliyon ; 9(4): e15072, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37151633

RESUMO

Globally, the deterioration of drinking water quality is a major public health problem that contributes to the spread of disease and causes death. Therefore, it is important to have regular quality control monitoring. This study aimed to assess the level of physicochemical and bacteriological quality of household drinking water and its contributing factors in flood-prone settlements of South Gondar Zone, Ethiopia. A community-based cross-sectional study was conducted in flood-prone settings of Northwest Ethiopia from January 17 to March 30, 2021. Structured questionnaires were used to gather the sociodemographic, environmental, and behavioral data. A total of 675 drinking water samples were collected from water storage containers of selected households. Logistic regression models were used for both univariate and multivariable studies. The survey included a total of 675 households. The mean values of pH (5.9 ± 1.03), turbidity (6.7 ± 2.21 NTU), and free residual chlorine (0.02 ± 0.01 mg/l) did not meet the WHO recommended limits for drinking water. The prevalence of fecal contamination of drinking water in the study area was 62.2% with [95% CI (53-60%)]. Family size [AOR = 2.205, 95% CI (1.375-3.536), absence of latrine [AOR = 3.449, 95% CI (1.349-8.823)], and lack of a separate container to draw water from its storage [AOR = 0.454, 95% CI (0.249-0.827)] were significant predictors for fecal contamination of household drinking water. In conclusion, the water quality in terms of pH, turbidity, residual chlorine, and bacteriological parameters was poor and not suitable for consumption. High prevalence of fecal contamination of water was found, and it was significantly associated with family size, the absence of a latrine, and the lack of a separate cap to take water from the storage. Therefore, continuous chlorination and monitoring its concentration, educating the community on how to use stored water, educating the advantage of having a latrine, and promoting point-of-use treatments such as filtration and boiling are needed.

18.
Anal Chim Acta ; 1265: 341282, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37230579

RESUMO

Food safety has emerged as a major global issue. Detecting foodborne pathogenic microorganisms and controlling them is vital to guard against foodborne diseases caused by microorganisms. However, the current detection methods need to meet the demand for real-time detection on the spot after a simple operation. Considering unresolved challenges, we developed an Intelligent Modular Fluorescent Photoelectric Microbe (IMFP) system containing a special detection reagent. This IMFP system can automatically monitor microbial growth in which the photoelectric detection, temperature control, fluorescent probe, and bioinformatics screen are integrated into one platform and employed to detect pathogenic microorganisms. Moreover, a specific culture medium was also developed, which matched the system platform for Coliform bacteria and Salmonella typhi. The developed IMFP system could attain a limit of detection (LOD) of about 1 CFU/mL for both bacteria, while the selectivity could reach 99%. In addition, the IMFP system was applied to detect 256 bacterial samples simultaneously. This platform reflects the high-throughput needs of fields for microbial identification and related requirements, such as the development of pathogenic microbial diagnostic reagents, antibacterial sterilization performance tests, and microbial growth kinetics. The IMFP system also confirmed the other merits, such as high sensitivity, high-throughput, and operation simplicity compared to conventional methods, and it has a high potential as a tool for application in the health and food security fields.


Assuntos
Contaminação de Alimentos , Inocuidade dos Alimentos , Contaminação de Alimentos/análise , Limite de Detecção , Meios de Cultura , Bactérias , Corantes Fluorescentes , Microbiologia de Alimentos
19.
Microorganisms ; 11(4)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37110497

RESUMO

High counts of bacteria are present in beach sand, and human health threats attributable to contact with sand have been reported. In this study, we investigated fecal indicator bacteria in the top surface sand of coastal beaches. Monitoring investigations were performed during a monsoon when rainfall occurs randomly, and the composition of the coliforms was analyzed. The coliform count in the top surface sand (depth < 1 cm) increased by approximately 100 fold (26-2.23 × 103 CFU/100 g) with increasing water content because of precipitation. The composition of the coliforms in the top surface sand changed within 24 h of rainfall, with Enterobacter comprising more than 40% of the coliforms. Estimation of factors that changed the bacterial counts and composition revealed that coliform counts tended to increase with increasing water content in the top surface sand. However, the abundance of Enterobacter was independent of the sand surface temperature and water content. Coliform counts in the top surface sand rapidly increased and the composition showed remarkable variations because of the supply of water to the beach following rainfall. Among them, some bacteria with suspected pathogenicity were present. Controlling bacteria in coastal beaches is important for improving public health for beachgoers.

20.
Heliyon ; 9(4): e14839, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37025863

RESUMO

Background: Two common techniques used in canteen hygiene supervision, are the coliform paper assay, which is the standard method, and the adenosine triphosphate (ATP) bioluminescence method. The coliform paper assay requires the incubation of the sample, which is time-consuming and does not provide a real-time assessment. Meanwhile, the ATP bioluminescence assay can provide real-time kitchenware cleanliness data. Objective: This study aimed to compare these two methods for evaluating the sanitary condition of kitchenware and explore whether the ATP bioluminescence assay can be used as a standard method in sanitary inspection. Methods: In this study, the cluster random sampling method was used to sample kitchenware from six canteens in the Hebei province, China. Samples were, assessed through the coliform paper test and ATP bioluminescence assay. Results: Kitchenware negative rates for the coliform paper method and the ATP test were 64.39% and 49.07%, respectively. The Escherichia coli positive detection rate grew steadily as the relative light units (RLU) value for the ATP technique increased. The kappa coefficient for the two methods was 0.549, indicating that the two methods yield relatively consistent results. Conclusion: Although currently not considered a standard method, simply using ATP detection is advantageous for quick on-site detection in catering unit hygiene supervision.

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