Microbiological and chemical characteristics of beaches along the Taranto Gulf (Ionian Sea, Southern Italy).

Coastal habitats provide important ecosystem services, such as the maintenance of ecological sustainability, water quality regulation, nutrient recycling, and sandy beaches which are important areas for recreation and tourism. The quality of seawater is generally measured by determining the concentrations of Escherichia coli and intestinal Enterococci, which might be affected by the persistent populations of these bacteria in sand. Sand might thus be a significant source of pathogen exposure to beachgoers. The quality of coastal recreational waters can also be affected by eutrophication, water discoloration, and harmful algal blooms, which pose additional human health risks. Here, we conducted a monitoring of the beaches quality along the Taranto Gulf by determining the concentrations of fecal indicator organisms, as well as other parameters that are not traditionally measured (physicochemical parameters, Pseudomonas aeruginosa, and harmful microalgae), in shallow seawater and sand sampled from three beaches. The concentrations of bacteria were determined using both standard microbiological methods and the IDEXX system. Our results demonstrate the utility of measuring a greater number of parameters in addition to those conventionally measured, as well as the importance of assessing the health risks posed by the sand matrix. Additional work is needed to develop rapid analytical techniques that could be used to monitor the microbiological parameters of solid matrices.

The use of BCYE medium for the detection of Legionella in environmental water samples: an appropriate update to ISO 11731:2017 standard?

We evaluated the diagnostic performances of 2 media (BCYE, MWY) on 951 Legionella-positive hospital water samples. MWY allowed detecting Legionella in 89.2% of samples, but in 10.8% (103/951) Legionella was found on BCYE plates only. In samples where Legionella was isolated with other microorganisms (663/951), MWY was essential to detect the majority of positive samples (349/663, 52.6%), as fewer plates resulted unreadable; however, in those containing Legionella only, a higher frequency of positive samples was recorded with BCYE (94.8%, 273/288) compared to MWY (85.1%, 245/288). Considering the 484 concordant positive samples, overall Legionella counts were significantly higher on BCYE (P = 0.0029), with 47% of samples showing higher counts on BCYE compared to MWY plates. Furthermore, discordant samples (positive on only one medium) showed different relative proportions between Legionella pneumophila and non-pneumophila, the latter being found more frequently on BCYE only (P = 0.0296).Our findings confirm the appropriateness of the ISO 11731:2017 update.

Tertiary hospital sewage as reservoir of bacteria expressing MDR phenotype in Brazil / Esgoto de hospital terciário como reservatório de bactérias expressando o fenótipo MDR no Brasil

High doses of antibiotics used in hospitals can affect the microbial composition of sewers, selecting resistant bacteria. In this sense, we evaluated the antibiotic resistance profile and the multiresistant phenotype of bacteria isolated in sewage from a tertiary hospital in the interior São Paulo state, Brazil. For bacteria isolation, 10 µL of sewage samples were sown in selective culture media and the isolates were identified using VITEK-2 automatized system. The antibiotic sensitivity test was performed by disk diffusion. High percentages of resistance were found for amoxicillin, ampicillin, ceftazidime, clindamycin, vancomycin and the multidrug-resistant phenotype (MDR) was attributed to 60.7% of the isolates. Our results show bacteria classified as critical/high priority by WHO List of Priority Pathogens (Enterococcus and Staphylococcus aureus resistant to vancomycin and Enterobacteriaceae resistant to carbapenems) in hospital sewage. Therefore, the implementation of disinfection technologies for hospital sewage would reduce the bacterial load in the sewage that will reach urban wastewater treatment plants, minimizing superficial water contamination and bacterial resistance spread in the environment.

Altas doses de antibióticos utilizados em hospitais podem afetar a composição microbiana dos esgotos, selecionando bactérias resistentes. Nesse sentido, avaliamos o perfil de resistência a antibióticos e o fenótipo multirresistente de bactérias isoladas em esgoto de um hospital terciário no interior do estado de São Paulo, Brasil. Para o isolamento de bactérias, foram semeados 10 µL das amostras de esgoto em meios de cultura seletivos e os isolados foram identificados usando o sistema automatizado VITEK-2. O teste de sensibilidade aos antibióticos foi realizado por disco-difusão em ágar. Elevadas porcentagens de resistência foram encontradas para amoxicilina, ampicilina, ceftazidima, clindamicina, vancomicina e o fenótipo multirresistente (MDR) foi atribuído a 60,7% dos isolados. Nossos resultados mostram bactérias classificadas como prioridade crítica/alta pela Lista de Patógenos Prioritários da OMS (Enterococcus e Staphylococcus aureus resistentes à vancomicina e Enterobacteriaceae resistentes aos carbapenêmicos) no esgoto hospitalar. Sendo assim, implementação de tecnologias de desinfecção do esgoto hospitalar reduziriam a carga bacteriana no esgoto que chegará às estações de tratamento de esgoto urbanas, minimizando a contaminação dos ecossistemas hídricos receptores e a disseminação da resistência bacteriana no ambiente.

Assessment of Drinking Water Sources for Water Quality, Human Health Risks, and Pollution Sources: A Case Study of the District Bajaur, Pakistan.

The focus of the present study was to assess the quality of different drinking water sources, impacts of poor water quality on human health, and to apportion pollution source(s) of the district Bajaur, Pakistan. Drinking water samples (n = 331) were randomly collected from springs, hand pumps, open wells, and tube wells and analyzed for physicochemical parameters including toxic elements, and bacteriological contamination (i.e., Escherichia coli). Furthermore, a questionnaire survey was conducted to record the cases of waterborne diseases in the study area. The results showed that total suspended solids and bacteriological contamination exceeded the permissible limits of the WHO in all four of the water sources. Among the potentially toxic elements, Cd, Pb, and Mn were above the permissible limits of the WHO in some samples. The hazard index for spring water was found to exceed the toxicity level (i.e., HI > 1) set by US EPA for both adults and children, while the sources from hand pumps, open wells, and tube wells were within the safe limit. The order for the overall safety level for water quality in the study area was tube wells > open wells > hand pumps > springs. The pollution source apportionment statistics revealed that both geogenic and anthropogenic activities are the sources of drinking water contamination. The results of the questionnaire survey indicated that reports of waterborne diseases were highest in respondents who took their drinking water from springs, whereas reports of diseases were moderate in respondents taking their water from open wells and hand pumps and lowest in respondents taking their water from tube wells. Based on the findings of the study, the tube well source of water is recommended for drinking water purposes.

Phenotypic and genotypic profile of the antimicrobial resistance of bacterial isolates and evaluation of physical and chemical potability indicators in groundwater in Brazil.

The aquatic environment has received increasing attention regarding the evolution of bacterial resistance, either as a source of resistance genes or as a matrix for the dissemination of these genes. We evaluated the physicochemical, microbiological and antimicrobial resistance characteristics of 160 samples from alternative water well solutions. According to Ordinance 2914/2011 - MS, 44 (27.5%) samples were considered unsafe if at least one physicochemical parameter exceeded permissible limits. Escherichia coli were found in 30.6% of the unregistered housing estates (UHE) and 1.9% of the local sanitary surveillance system (RW). The total of 158 bacterial strains were isolated from 13 (25%) RW and 68 (63%) UHE, 132 of which (83.5%) were obtained from UHE samples. In the investigation of resistance genes, tetA, qnrS and qnrB genes were detected in three, one and eight isolates, respectively. Our results emphasize the importance of constant surveillance and control of the quality of water supplies.

Molecular characterization and antimicrobial resistance profiles of Mycobacterium tuberculosis complex in environmental substrates from three dairy farms in Eastern Cape, South Africa.

This study analysed 330 environmental substrates from three dairy farms for the occurrence, drug resistance and the genetic mutations of MTBC (Mycobacterium tuberculosis complex) in Eastern Cape, South Africa using PCR, while the Genotype MTBDRplus assay was used for drug susceptibility and genetic mutations analyses. About 17% (55/330) of the samples were positive for MTBC at 16.7% (water), 13.3% (soil) and 20% (hayfeed). Isoniazid resistance was detected in 47.3% (26/55) of the samples while 16.4% (9/55) were multidrug-resistant. Genetic mutations were detected on the rpoB gene (resistance to rifampicin) with frequencies ranging from 53.6% (D516V) to 21.4% (H526D), while mutations on the katG and inhA genes (resistance to isoniazid) ranged between 14.3% and 80%. Incidents of diverse genetic mutations in the environmental matrices suggest possible resistance to other anti-TB drugs not assayed in this study and emphasizes the need for continuous monitoring of drug resistance patterns for timely detection and control of new clonal groups of MTBC.

Sediment re-suspension as a potential mechanism for viral and bacterial contaminants.

Pathogenic enteric viruses and bacteria tend to occur in higher concentrations and survive longer in aquatic sediments than suspended in the water column. Re-suspension of these organisms can result in a significant degradation of overlying water quality. Additionally, the re-suspension of microbial pathogens in artificial irrigation canals could endanger the consumption of fresh and ready-to-eat produce. Irrigation water has been implicated in numerous fresh produce outbreaks over the last 30 years. This study aimed to quantify the proportions of bacterial and viral re-suspension from sediment in a recirculating flume with varying velocities. MS2 coliphage and Escherichia coli were found to re-suspend at rates that were not significantly different, despite organism size differences. However, E. coli re-suspension rates from sand and clay were significantly different. This suggests that likely sediment-associated particles were recovered with the organisms attached. Similar re-suspension rates are hypothesized to be due to the dynamics of sediment transport, rather than that of the organisms themselves. This study also indicated that the re-suspension of sediment at very low velocities (e.g., less than 10 cm/s), could impact the microbiological quality of the overlaying water. Results from this study conclude that sediment could be a viable mechanism for irrigation water contamination.

Swimming Pool safety and prevention at the time of Covid-19: a consensus document from GSMS-SItI.

Public health measures to cope with the Covid-19 pandemic, imposed also a shutdown of sports facilities and swimming pools. Safety issues related to recreational waters were emerging during the lockdown, rising concerns on how and when reopening pools and on how improve their management while SARS-CoV-2 is circulating in the population. The GSMS-SItI, Working Group on Movement Sciences for Health of the Italian Society of Hygiene Preventive Medicine and Public Health, discussed and summarized some indications for a suitable preventive approach. Several measures are highlighted, including social distancing, optimized water management, airflow and microclimatic parameters in the pool as well in the annexed rooms, verification of sanitation procedures. The GSMS-SItI underlines that prevention should be based on monitoring of the local epidemiological situation and on the constant collaboration with the local health authority and the national health service.

Marine Microbial Response to Heavy Metals: Mechanism, Implications and Future Prospect.

Growing levels of pollution in marine environment has been a matter of serious concern in recent years. Increased levels of heavy metals due to improper waste disposal has led to serious repercussions. This has increased occurrences of heavy metals in marine fauna. Marine microbes are large influencers of nutrient cycling and productivity in oceans. Marine bacteria show altered metabolism as a strategy against metal induced stress. Understanding these strategies used to avoid toxic effects of heavy metals can help in devising novel biotechnological applications for ocean clean-up. Using biological tools for remediation has advantages as it does not involve harmful chemicals and it shows greater flexibility to environmental fluctuations. This review provides a comprehensive insight on marine microbial response to heavy metals and sheds light on existing knowledge about and paves for new avenues in research for bioremediation strategies.

Rapid detection of Escherichia coli using bacteriophage-induced lysis and image analysis.

Rapid detection of bacterial pathogens is a critical unmet need for both food and environmental samples such as irrigation water. As a part of the Food safety Modernization Act (FSMA), The Produce Safety rule has established several requirements for testing for the presence of generic Escherichia coli in water, but the current method available for testing (EPA M1603) demands specified multiple colony verification and highly trained personnel to perform these tests. The purpose of the study was to assess a phage induced bacterial lysis using quantitative image analysis to achieve rapid detection of E. coli at low concentrations within 8 hours. This study aimed to develop a simple yet highly sensitive and specific approach to detect target bacteria in complex matrices. In the study, E. coli cells were first enriched in tryptic soy broth (TSB), followed by T7 phage induced lysis, concentration, staining and fluorescent imaging. Image analysis was conducted including image pre-processing, image segmentation and quantitatively analysis of cellular morphological features (area, eccentricity and full width at half maximum). Challenge experiments using realistic matrices, including simulated fresh produce wash water, coconut water and spinach wash water, demonstrated the method can be applied for use in situations that occur in food processing facilities. The results indicated E. coli cells that are lysed by T7 phages demonstrated significantly (P < 0.05) higher extracellular DNA release, altered cellular shape (from rod to circular) and diffused fluorescent signal intensity. Using this biosensing strategy, a sensitivity to detect Escherichia coli at 10 CFU/ml within 8 hours was achieved, both in laboratory medium and in complex matrices. The proposed phage based biosensing strategy enables rapid detection of bacteria and is applicable to analysis of food systems. Furthermore, the steps involved in this assay can be automated to enable detection of target bacteria in food facilities without extensive resources.

Validation and applicability of an alternative method for dialysis water and dialysate quality analysis / Validação e aplicabilidade de um método alternativo para análise da qualidade da água e do dialisato em diálise

ABSTRACT Introduction: In hemodialysis, patients are exposed to a large volume of water, which may lead to fatal risks if not meeting quality standards. This study aimed to validate an alternative method for monitoring microbiological quality of treated water and assess its applicability in dialysis and dialysate analysis, to allow corrective actions in real-time. Methods: Validation and applicability were analyzed by conventional and alternative methods. For validation, E. coli standard endotoxin was diluted with apyrogenic water in five concentrations. For the applicability analysis, treated water for dialysis was collected from different points in the treatment system (reverse osmosis, drainage canalization at the storage tank bottom, reuse, and loop), and dialysate was collected from four machines located in different rooms in the hemodialysis sector. Results: The validation results were in accordance with the Brazilian Pharmacopoeia acceptance criteria, except for the last two concentrations analyzed. In addition, the ruggedness criterion performed under the US Pharmacopoeia was in agreement with the results. Discussion: A limiting factor in the applicability analysis was the absence of the endotoxin maximum permitted level in dialysate by the Brazilian legislation. When comparing the analysis time, the alternative method was more time-consuming than the conventional one. This suggests that the alternative method is effective in the case of few analyses, that is, real-time analyses, favoring corrective actions promptly. On the other hand, it does not support the implementation of the alternative method in a laboratory routine due to the high demand for analyses.

RESUMO Introdução: Na hemodiálise, os pacientes são expostos a um grande volume de água, o que pode levar a riscos fatais se não cumprir com padrões de qualidade. Este estudo teve como objetivo validar um método alternativo para monitorar a qualidade microbiológica da água tratada e avaliar sua aplicabilidade em análises de diálise e dialisato, para permitir ações corretivas em tempo real. Métodos: A validação e aplicabilidade foram analisadas por métodos convencionais e alternativos. Para validação, a endotoxina padrão de E. coli foi diluída com água apirogênica em cinco concentrações. Para a análise de aplicabilidade, a água tratada para diálise foi coletada em diferentes pontos do sistema de tratamento (osmose reversa, canalização de drenagem no fundo do tanque de armazenamento, reutilização e circuito) e o dialisato foi coletado em quatro máquinas localizadas em diferentes salas do setor de hemodiálise. Resultados: Os resultados da validação obedeceram aos critérios de aceitação da Farmacopeia Brasileira, com exceção das duas últimas concentrações analisadas. Além disso, o critério de robustez realizado sob a Farmacopeia dos EUA estava de acordo com os resultados. Discussão: Um fator limitante na análise de aplicabilidade foi a ausência do nível máximo permitido de endotoxina no dialisato pela legislação brasileira. Ao comparar o tempo de análise, o método alternativo consumiu mais tempo que o convencional. Isso sugere que o método alternativo é eficaz no caso de poucas análises, ou seja, análises em tempo real, favorecendo ações corretivas imediatamente. Por outro lado, não suporta a implementação do método alternativo em uma rotina de laboratório devido à alta demanda por análises.

Monitoring and controlling bacteria in pharmaceutical industries water system.

AIM: This research aimed to monitor pharmaceutical water system by sampling water from all treatment stages, identify bacterial isolates from each phase and determine the most suitable methods to control them. METHODS AND RESULTS: Water samples were collected and examined from pharmaceutical water system in a pharmaceutical factory in Giza, Egypt during 12 months, once per month (from December 2017 to November 2018) from 15 points covering all stages of the treatment process starting from wells, pre-treatment points; treatment points ending with purified points which are the main source of water used in all pharmaceutical process. In all, 216 water samples were collected and examined, 156 isolates were selected according to morphological characteristics. VITEK system 2 (BioMérieux) was used for identification of all isolates resulting in 24 different identified bacteria. Antibiotic assay test using disc diffusion methods were carried out using seven antibiotics from different groups. Several disinfectants were also examined for efficacy against the isolates to control micro-organisms in water treatment stage and manufacturing area. The effect of different preservatives (parabens, acids and alcohols) in various pharmaceutical formulas was also tested on bacterial isolates, 63% of formulas were effective against all bacterial isolates. CONCLUSION: Ciprofloxacin was the most effective antibiotic, mixture of 0·45% peracetic acid plus 2·2% of hydrogen peroxide (Minncare 1%) was maximally effective disinfectant, and Cronobacter sakazakii was the most resistant micro-organism against 22·7% of tested preservatives. SIGNIFICANCE AND IMPACT OF THE STUDY: Controlling pharmaceutical manufacturing operation from pathogenic bacteria that affect the quality of drugs.

Validation and applicability of an alternative method for dialysis water and dialysate quality analysis.

INTRODUCTION: In hemodialysis, patients are exposed to a large volume of water, which may lead to fatal risks if not meeting quality standards. This study aimed to validate an alternative method for monitoring microbiological quality of treated water and assess its applicability in dialysis and dialysate analysis, to allow corrective actions in real-time. METHODS: Validation and applicability were analyzed by conventional and alternative methods. For validation, E. coli standard endotoxin was diluted with apyrogenic water in five concentrations. For the applicability analysis, treated water for dialysis was collected from different points in the treatment system (reverse osmosis, drainage canalization at the storage tank bottom, reuse, and loop), and dialysate was collected from four machines located in different rooms in the hemodialysis sector. RESULTS: The validation results were in accordance with the Brazilian Pharmacopoeia acceptance criteria, except for the last two concentrations analyzed. In addition, the ruggedness criterion performed under the US Pharmacopoeia was in agreement with the results. DISCUSSION: A limiting factor in the applicability analysis was the absence of the endotoxin maximum permitted level in dialysate by the Brazilian legislation. When comparing the analysis time, the alternative method was more time-consuming than the conventional one. This suggests that the alternative method is effective in the case of few analyses, that is, real-time analyses, favoring corrective actions promptly. On the other hand, it does not support the implementation of the alternative method in a laboratory routine due to the high demand for analyses.

Effects of industrial effluents on the quality of water in Namanve stream, Kampala Industrial and Business Park, Uganda.

OBJECTIVE: Kampala Industrial and Business Park (KIBP) is one of the premier and the most successful Ugandan industrial complexes that impact the inner Murchison bay of Lake Victoria. The current study aimed at evaluating the effect of industrial effluents on the physicochemical and microbiological quality of water taken from four different sites along Namanve stream in KIBP, Wakiso district, Uganda. RESULTS: All the water quality parameters were below WHO maximum permissible limits except turbidity, electrical conductivity and Escherichia coli count. Mean values of the monitored water quality parameters increased from the point of effluent discharge downstream of Namanve stream.

A Syringe-Based Biosensor to Rapidly Detect Low Levels of Escherichia Coli (ECOR13) in Drinking Water Using Engineered Bacteriophages.

A sanitized drinking water supply is an unconditional requirement for public health and the overall prosperity of humanity. Potential microbial and chemical contaminants of drinking water have been identified by a joint effort between the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), who together establish guidelines that define, in part, that the presence of Escherichia coli (E. coli) in drinking water is an indication of inadequate sanitation and a significant health risk. As E. coli is a nearly ubiquitous resident of mammalian gastrointestinal tracts, no detectable counts in 100 mL of drinking water is the standard used worldwide as an indicator of sanitation. The currently accepted EPA method relies on filtration, followed by growth on selective media, and requires 24-48 h from sample to results. In response, we developed a rapid bacteriophage-based detection assay with detection limit capabilities comparable to traditional methods in less than a quarter of the time. We coupled membrane filtration with selective enrichment using genetically engineered bacteriophages to identify less than 20 colony forming units (CFU) E. coli in 100 mL drinking water within 5 h. The combination of membrane filtration with phage infection produced a novel assay that demonstrated a rapid, selective, and sensitive detection of an indicator organism in large volumes of drinking water as recommended by the leading world regulatory authorities.

Variations in bacterial community structures during geothermal water recharge-induced bioclogging.

Characterizing bacterial communities is of great significance for targeted control of bacteria-induced clogging during geothermal water recharge. Based on a series of laboratory-scale percolation experiments, the variations in bacterial community diversity, composition, and structure were investigated during simulated geothermal water recharge using high-throughput sequencing technology. The Chao, Shannon, and Evenness indexes were used to quantify the richness, diversity, and evenness of the bacterial community, respectively. The results show that the richness of the bacterial community initially increased and then decreased in the sand columns during the experiments of geothermal water recharge, while the changes in bacterial diversity and evenness were not apparent. A variety of bacterial phyla were found, among which Proteobacteria was predominant (88.31%), followed by Actinobacteria, Bacteroidetes, and Firmicutes (4.23%, 3.44%, and 2.49%). For the non-Proteobacterial phyla, Actinobacteria gradually disappeared while Bacteroidetes and Firmicutes were detected during the percolation experiments. This study implies that, despite the variations in the bacterial community, a core group of bacteria persists during geothermal water recharge, and thus a targeted control of bacteria-induced clogging during geothermal water recharge should be feasible.

Effects of bathing intensity, rainfall events, and location on the recreational water quality of stream pools in southern Ecuador.

Bathing in natural waters is a highly demanded recreational activity in tropical countries because of climatic conditions and availability of bathing sites; but, do users know the water quality of these sites? We determined the physicochemical and microbiological water quality of a highly used bathing site in southern Ecuador. We assessed how bather attendance, rainfall events, and pool location alters the recreational water quality (RWQ). Most of the parameters measured in the stream pools did not accomplish the Ecuadorian and international regulations for recreational water quality. Microbiological water quality diminishes from upstream to downstream pools because of human activities and bathing intensity having potential effects on bather health and eco-touristic development. We found that an increase of bathers is strongly associated with a growing concentration of Escherichia coli. It is suggested better land-use practices and review thoroughly the Ecuadorian regulation to assure a healthy RWQ. Further efforts are needed to identify more risky bathing sites, determine pollution sources, and establish a long-term monitoring program to support the touristic development in countries looking for diversifying their economy.

Impact of substrate material and chlorine/chloramine on the composition and function of a young biofilm microbial community as revealed by high-throughput 16S rRNA sequencing.

The bacterial composition of biofilms in drinking water distribution systems is significantly impacted by the disinfection regime and substrate material. However, studies that have addressed the changes in the biofilm community during the early stage of formation (less than 10 weeks) were not yet adequate. Here, we explore the effects of the substrate materials (cast iron, stainless steel, copper, polyvinyl chloride, and high density polyethylene) and different disinfectants (chlorine and chloramine) on the community composition and function of young biofilm by using 16S rDNA sequencing. The results showed that Alphaproteobacteria (39.14%-80.87%) and Actinobacteria (5.90%-40.03%) were the dominant classes in chlorine-disinfection samples, while Alphaproteobacteria (17.46%-74.18%) and Betaproteobacteria (3.79%-68.50%) became dominant in a chloraminated group. The infrequently discussed genus Phreatobacter became predominant in the chlorinated samples, but it was inhibited by chloramine and copper ions. The key driver of the community composition was indicated as different disinfectants according to principle coordination analysis (PCoA) and Permutational multivariate analysis of variance (Adonis test), and the bacterial community changed significantly over time. Communities of biofilms grown on cast iron showed a great distance from the other materials according to Bray-Curtis dissimilarity, and they had a unique dominant genus, Dechloromonas. A metagenomics prediction based on 16S rDNA was used to detect the functional pathways of antibiotic biosynthesis and beta-lactam resistance, and it revealed that several pathways were significantly different in terms of their chlorinated and chloraminated groups.