Bacterial Contamination Of Water Research Articles

Rapid detection of bactericidal efficacy of nanoparticles coated polyurethane foam by synchronous fluorescence spectroscopy

The ability of right-angled synchronous fluorescence spectroscopy (SFS) was explored to analyse the bacterial load in water treated with green synthesized silver nanoparticles (AgNPs) coated polyurethane foam (PUF). Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus) bacteria cultured in nutrient broth were diluted in autoclaved water containing NPs-coated PUF. The survival rate of S. aureus and E. coli lowered after ten minutes as compared to P. aeruginosa; however, after thirty minutes, the percentage viability dropped and recorded as 3.4%, 0.9%, and 0.1% for E. coli, P. aeruginosa and S. aureus respectively in the treated suspensions. No spectral change was observed in the fluorescence emission from the positive control and treated bacterial suspension owing to the masking effect of the emission from nutrient broth. In parallel, SF spectra recorded for directly picked bacterial colony dissolved in water showed remarkable drop in tryptophan emission after treatment with NPs-coated PUF. The SF data changes were assisted by hierarchical cluster analysis, which also made it possible to distinguish between positive control and treated bacterial suspensions. SFS has shown to be a reliable substitute for the culture plate approach for the quick identification of bacterial contamination in water.

Numerical analysis of a single channel exposed core elliptical shaped PCF based highly sensitive SPR sensor for wide RI sensing

This study presents a numerical study of a highly sensitive photonic crystal fiber (PCF) surface plasmon resonance (SPR) sensor capable of detecting five types of cancer and bacterial contamination in water. By precisely arranging only two air holes in a single channel of an elliptical-shaped PCF, the sensor maximizes interaction between core-guided modes and surface plasmon polaritons (SPP) along the fiber. Evaluation using COMSOL Multiphysics simulation software, based on finite element method (FEM), demonstrates outstanding sensor performance across a wide refractive index (RI) range (1.33 to 1.43). With a maximum wavelength sensitivity (WS) of 188,000 nm/RIU and amplitude sensitivity (AS) of -22,377.99 RIU−1, the sensor achieveStructural Design and Methodologys a sensor resolution (SR) of 5.3191 × 10−7 RIU and figure of merit (FOM) of 854.55 RIU−1. Notably, it exhibits AS and WS values tailored for specific cancer cell types and water contamination. These results endorse the sensor’s potential in diverse biological and molecular analyte RI detection applications within the visible to near-infrared (VNIR) range (0.55 to 4 µm), offering high sensitivity, affordability, wide sensing range, good linearity, low propagation loss, and simplicity in construction.

The effect of various drugs on the survival of sterlet fry in bacterial contamination of water

Currently, aquaculture is a reliable source of increasing the volume of fish food products and serves as a guarantor of food security. The sterlet Acipenser ruthenus L. is one of the main objects of freshwater aquaculture. Feeding with artificial feed, high planting densities and other negative factors of industrial fish farming inevitably lead to increased stress loads. This affects the physiological state of fish. Disturbances in the functioning of the immune system leads to outbreaks of infectious diseases and epizootic disadvantage of pond fish farms. In modern aquaculture, various antibiotics, probiotics and plant preparations are used to treat and prevent bacterial diseases. In this paper, the effect of different feed additives on the survival rate of sterlet fry to infectious agents was investigated. For this purpose, 150 individuals each were seeded into separate pools with high content of myxobacteria and aeromonads in the water microflora. Studies were conducted in 5 separate pools: control group with feed and 4 experimental pools with different feed additives. The duration of the experiment was 75 days. During the experiment, the number of surviving fries was recorded, and at the end, survival rate was calculated as a percentage of the total number of fish initially planted in each pool. Differences in the effect of different feed additives on the survival rate of fry were found. The highest escapement was recorded in the control group and the least in the group with Antibac-100. In the other experimental groups, the percentage of surviving fry was higher than in the control.

Rapid measurement of bacterial contamination in water: A catalase responsive-electrochemical sensor

The present study describes the development of a potentiometric sensor for microbial monitoring in water based on catalase activity. The sensor comprises a MnO2-modified electrode that responds linearly to hydrogen peroxide (H2O2) from 0.16 M to 3.26 M. The electrode potential drops when the H2O2 solution is spiked with catalase or catalase-producing microorganisms that decompose H2O2. The sensor is responsive to different bacteria and their catalase activities. The electrochemical sensor exhibits a lower limit of detection (LOD) for Escherichia coli at 11 CFU/ml, Citrobacter youngae at 12 CFU/ml, and Pseudomonas aeruginosa at 23 CFU/ml. The sensor shows high sensitivity at 3.49, 3.02, and 4.24 mV/cm2dec for E. coli, C. youngae, and P. aeruginosa, respectively. The abiotic sensing electrode can be used multiple times without changing the response potential (up to 100 readings) with a shelf-life of over six months. The response time is a few seconds, with a total test time of 5 min. Additionally, the sensor effectively tested actual samples (drinking and grey water), which makes it a quick and reliable sensing tool. Therefore, the study offers a promising water monitoring tool with high sensitivity, stability, good detection limit, and minimum interference from other water contaminants.

Peroxidase-mimetic colloidal nanozyme from ozone-oxidized lignocellulosic biomass for biosensing of H2O2 and bacterial contamination in water

Peroxidase-mimetic colloidal nanozyme from ozone-oxidized lignocellulosic biomass for biosensing of H2O2 and bacterial contamination in water

Risk Factors Affecting the Bacterial Contamination in Water of Thailand’s Upper South 2020 - 2022

Bacterial contamination in water is an important cause of human health problems. Water-borne infections are among the top 10 reasons for illness in Thailand and accounted for 40 % of all infections necessitating surveillance. The purpose of this study was to identify environmental factors influencing bacterial contamination in water in the upper southern region of Thailand. Secondary data on water quality were obtained from 2 Regional Medical Sciences Centers, and environmental data were collected from the National Statistical Office’s annual reports for 2020 - 2022. A multiple logistic regression model was used to investigate the factors influencing bacterial contamination to exceed the standard. There were 674 water samples contaminated with bacteria, which implied 10.97 % of the total number of samples. The factors that were significantly associated with greater bacterial contamination than standard were provinces and years of production, water types, bacterial types and rainfall levels. Bacteria were more likely to contaminate the water generated in Chumphon province. The quantity contamination for consumption water varied by years of production, with Total Coliform Bacteria (TCB) being the most contaminated bacterial strain as rainfall increases. High precipitation deteriorated biological water quality, which was the origin of water-borne diseases. Entrepreneurs and other connected organizations must constantly watch for bacterial contamination when there is a change in a manufacturing site or when the season changes from hot to rainy. HIGHLIGHTS Environmental changes have an influence on the bacterial contamination of water in Thailand’s upper southern region Rainfall, production location, year of production, types of bacteria, and kinds of water are risk factors related to the presence of bacteria contaminants in water There is greater bacterial contamination in the water as the amount of rainfall increases or rains more Indicator bacteria are more easily detected in water than disease bacteria Bacteria are more likely to be detected in processed water and household water than in drinking water and ice for consumption GRAPHICAL ABSTRACT

A Simple Biosensor Based on Streptavidin-HRP for the Detection of Bacteria Exploiting HRPs Molecular Surface Properties

Bacterial contamination of water and food sources is still a major source of diseases. Early detection of potential pathogens is key to prevent their spreading and severe health risks. Here, we describe a fast, low-cost detection assay based on horseradish peroxidase (HRP) conjugated to streptavidin for the direct identification of bacteria. Streptavidin can bind to bacterial cells due to its high affinity for biotin, a natural component of microbial cell surfaces. Upon binding to bacteria, the HRP converts a chromogenic substrate, resulting in a visible color change. In the present study, we evaluated different detection platforms regarding their compatibility with the detection principle. To reduce background signals and increase the sensitivity of HRP-based assays, the binding of HRP to surfaces and biomolecules was intensively investigated. The final assay successfully detected the most relevant bacterial strains in drinking water, such as Escherichia coli, Klebsiella pneumonia, and Enterobacter cloacae.

Bacterial contamination of water used as thermal transfer fluid in fluid-warming devices

Recent reports implied heater-cooler units (HCU), which are used for warming of infusions, blood or in ECMO devices, as possible origin of healthcare-associated infections (HAIs) with potentially pathogenic bacteria like nontuberculous mycobacteria [1]. This represents a source of contamination in a usually sterile setting. Aim of this study is to analyse water from infusion heating devices (IHDs) for bacterial contamination and to raise the question if IHDs act as a possible source in the transmission of HAIs. 300-500 ml of thermal transfer fluid (TTF) derived from the reservoirs of 22 independent IHDs were collected and processed on different selective and non-selective media for colony count and identification of bacteria. Strains of Mycobacterium species (spp.) were further analysed by whole genome sequencing. Bacterial growth was observed in each of the 22 collected TTFs after cultivation at 22°C and 36°C. Pseudomonas aeruginosa was the most frequent pathogen identified, being present in 13.64% (3/22) at > 100 CFU/100mL. Colonization with Mycobacterium chimaera, Ralstonia pickettii and Ralstonia mannitolilytica was detectable in 9.09% (2/22) of the isolates. Primary sequencing of the detected M. chimaera suggests a close relationship to a M. chimaera strain detected in an outbreak in Switzerland, which led to the death of two patients. A contamination of the TTF represents a germ reservoir in a sensitive setting. Handling errors of the IHD may lead to distribution of opportunistic or facultative bacterial pathogens, increasing the risk of nosocomial infection transmission.

Nanosecond bacteria inactivation realized by locally enhanced electric field treatment

Bacterial contamination in water is still a critical threat to public health; seeking efficient water disinfection approaches is of great significance. Here we show that locally enhanced electric field treatment (LEEFT) by electrodes modified with nanoscale tip structures can induce ultrafast bacteria inactivation with nanosecond electrical pulses. A lab-on-a-chip device with gold nanowedges on the electrodes is developed for an operando investigation. Attributed to the lightning-rod effect, the bacteria at the nanowedge tips are inactivated by electroporation. A single 20 ns pulse at 55 kV cm−1 has achieved 26.6% bacteria inactivation, with ten pulses at 40 kV cm−1 resulting in 95.1% inactivation. LEEFT lowers the applied electric field by about 8 fold or shortens the treatment time by at least 106 fold, compared with the system without nanowedges. Both Gram-positive and Gram-negative bacteria, including antibiotic-resistant bacteria, are inactivated with nanosecond pulses by LEEFT. According to simulation, when the membrane of the cell located at the nanowedge tip is directly charged by the concentrated charges at the tip, it is charged much faster and to a much higher level, leading to instant electroporation and cell inactivation. Efficient ways to disinfect water from bacterial contamination are essential for public health. Locally enhanced electric field treatment can be used to induce ultrafast bacteria inactivation with nanosecond electrical pulses.

Recyclable ferroferric oxide@titanium dioxide@molybdenum disulfide with enhanced enzyme-like activity under visible light for effectively inhibiting the growth of drug-resistant bacteria in sewage.

With the development of social industry and the increase in domestic sewage discharge, pathogenic bacterial contamination in water has become a serious health and environmental problem. It is important to design sewage treatment reagents with effective pathogenic bacterial removal and recyclability. In this work, we developed a nanocomposite, Fe3O4@TiO2@MoS2, with once-for-all effects of photocatalytic, magnetic, and peroxidase-like activities for solving the above-mentioned problems. The loading of MoS2 may cause the band gap of Fe3O4@TiO2 to decrease from 3.11 eV to 2.85 eV, demonstrating increased photocatalytic activity under visible light, based on the synergistic impact of Fe3O4@TiO2 and MoS2. In return, the peroxidase-like activity of Fe3O4@TiO2@MoS2 was significantly higher than that of Fe3O4 and MoS2 alone, resulting in the generation of more hydroxyl radicals (˙OH) for combating the drug-resistant broad-spectrum β-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus. The antibacterial mechanism study showed that Fe3O4@TiO2@MoS2 could effectively inhibit bacterial growth by destroying the bacterial biofilm and genome via the peroxidase-like activity as well as photocatalytic activity. In addition, Fe3O4@TiO2@MoS2 has excellent paramagnetic properties, which can achieve magnetic recovery after wastewater treatment. Even after three times of recycling, its antibacterial effect can remain above 98.8%.

A glass matrices-assisted quantum dots-based biosensor for selective capturing and detection of Escherichia coli.

Bacterial contamination of water and food is a grave health concern rendering humans quite vulnerable to disease(s), and proving, at times, fatal too. Exploration of the novel diagnostic tools is, accordingly, highly called for to ensure rapid detection of the pathogenic bacteria, particularly Escherichia coli. The current manuscript, accordingly, reports the use of silane-functionalized glass matrices and antibody-conjugated cadmium telluride (CdTe) quantum dots (QDs) for efficient detection of E. coli. Synthesis of QDs (size: 5.4-6.8 nm) using mercaptopropionic acid (MPA) stabilizer yielded stable photoluminescence (∼62%), corroborating superior fluorescent characteristics. A test sample, when added to antibody-conjugated matrices, followed by antibody-conjugated CdTe-MPA QDs, formed a pathogen-antibody QDs complex. The latter, during confocal microscopy, demonstrated rapid detection of the selectively captured pathogenic bacteria (10 microorganism cells/10 μL) with enhanced sensitivity and specificity. The work, overall, encompasses establishment and design of an innovative detection platform in microbial diagnostics for rapid capturing of pathogens in water and food samples.

Increased morbidity of children with sickle cell disease facing bacterial contamination of water in some areas of the Province of Kenitra (Morocco)

Introduction. Sickle cell disease is the most common genetic disease in the world. It is manifested by painful crises, chronic hemolytic anemia and severe infectious episodes leading to multiple hospitalizations. Our work aimed to study repetitive childhood sickle cell crises that can potentially be linked to socioeconomic characteristics and environmental children in hospital at the University Hospital of Kenitra. Methods: This study focuses on children with sickle cell disease (N=28) hospitalized during 2021 at the University Hospital of Kenitra, as well as the bacteriological analysis of monitoring wells located in the residential areas of these patients, all from the province of Kenitra. Results: The mean age of the patients was 8.83 years; the age group under 6 represents 35.71%. The results show that 60.72% of these children come from rural areas, and the reasons for admission were dominated by infections (60.71%). Our results show that the bacteriological analysis of well water highlights the presence of some pathogens; the average concentration of total germs at 22˚C reaches 761 CFU/ml, and that of streptococci faeces is 4 CFU/ml especially in samples from rural areas (Mnasra, Sidi Taibi, Moulay Boussellham) inhabited by these children, which greatly exceeds international standards.

Goalpara and bacterial water contamination

The current world is fighting with several issues like Covid- 19, Poverty, Malnutrition and many more. But there are some other issues which are still ignored by considering as less important. Among these least concern issues death due to drinking of contaminated water or ingestion of food come in contact with polluted water holds a major percentage. The study was conducted to determine the quality of water contamination trend in Goalpara district of Assam. The presence of fecal and total coliform were tested by Most Probable Number as well as Membrane filtration tests (MF) to rule out any chance of missing out any positive sample. During the study we identified the causative agent which contaminates the water in the targeted district of Assam, India. Water samples were collected from drinking water supplies and from routine household chores. During the study, evidence of microorganisms such as Escherichia coli, Streptococci, Staphylococci and Klebsiella were found. Escherichia coli were isolated from most numbers of samples, whereas Shigella spp. has the lowest contamination rate. The water with highest contamination rate was from Rangjuli development block and Lakhipur development block gave the lowest water contamination rate. The most prevalent bacteria were Escherichia coli.

Analisis Kandungan Cemaran Bakteri Coliform Pada Air Rendaman Tahu di Pabrik Tahu Wilayah Kalideres Jakarta Barat

Tofu is a food source containing high vegetable protein. Tofu is in great demand by most of the Indonesian people because it contains high nutrition and the price is relatively cheap and affordable. To produce tofu requires good hygiene and sanitation, such as providing clean raw materials and water sources that are free from contamination. To determine whether the water source has been contaminated with microbes or not, the Coliform bacteria indicator in the water sample is used. In testing Coliform bacterial contamination in water or raw materials, the Most Probable Number (MPN) method is used to calculate the amount or level of microbial contamination in determining the quality or quality of water and raw materials by referring to the MPN table. This study aims to determine the level of Coliform bacteria contamination in tofu soaking water in a tofu factory in the Kalideres area of ??West Jakarta. The design of this research is a descriptive laboratory type which was carried out in March-June 2020 at the Indonesian Social Solidarity STIKes Laboratory. Based on the results of the research on the presumptive test, it was found that 1 positive tube was contaminated with Coliform in the KR tofu factory and 3 positive tubes at the DN factory. The presumptive test was continued to confirmatory test and found 5 positive tubes polluted at the DD factory, 2 positive tubes at the KR factory and 3 positive tubes at the DN factory. The positive tube from the confirmation test was calculated for the contamination index value (MPN) and obtained 21000 mpn/ml for the DD factory, 4000 mpn/ml for the KR factory and 9000 mpn/ml for the DN factory. It can be concluded that there is Coliform bacterial contamination in all tofu soaking water samples in 3 tofu factories with the MPN index value having passed the contamination threshold.

MXene–laden bacteriophage: A new antibacterial candidate to control bacterial contamination in water

In this study, Ti3C2 MXene nanofragments with a size distribution of about 20 nm were laden on the well-characterized bacteriophages via electrostatic bonding, introducing a new antibacterial agent as a modified virus vector to be used in high-risk bacterial environment. At > MIC of MXene, the MXene-functionalized bacteriophage would be much more active in attacking the bacteria because of the high specificity for host receptors’ recognition and targeting ability of bacteriophage and bacterial surface negative charge when comparing to the phage alone. Also, the induced positive surface moieties drive MXene nanofragments toward the negative surface charge of bacteria. The main mechanisms are the specific targeting capacity of bacteriophages, often by lysing the host and bursting out, and the physical interaction of MXene nanofragments with the bacterial cell membrane, which may rupture the cell wall in microbial death. The results described that the Ti3C2 MXene significantly enhanced the bacteriophage adsorption rate and stability over long-standing cultivation in aquatic environments providing superior antibacterial efficacy against the bacterial cells target. The Ti3C2 MXene-laden bacteriophage demonstrated a fast, efficient attaching to bacterial host cells, high antibacterial potential, and reduced 99.99% of the artificial contamination in water samples. Interestingly, no re-growth of target bacteria was observed in the samples during the experiment period, and the count of bacteria constantly remained below the detection threshold. This research raises attention in proposing a novel antibacterial agent to be synthesized through a simple one-step technique devoid of shortcomings of post-treatments in conventional antibacterial treatments.

Bringing Light to Science Undergraduate Students: A Successful Laboratory Experiment Illustrating the Principles and Applications of Bioluminescence

Although many laboratory experiments are available to illustrate spectrophotometric or fluorometric methods, few of them introduce the use of luminometry to students. Bioluminescence, a subtype of chemiluminescence, is produced when an enzyme-catalyzed chemical reaction gives rise to light emission. Despite the advantages of bioluminescent methods, including sensitivity and specificity, and their increasing use in experimental sciences and biomedical laboratories, their presence in courses is almost nonexistent. The luciferase-catalyzed enzymatic reaction has generated a myriad of practical applications, including those derived from the measurement of the ATP consumed in the reaction. In particular, the measurement of ATP levels in drinking or stored waters directly correlates with their bacteria content, facilitating the development of rapid methods for detecting bacterial contamination. This avoids the long waiting time associated with traditional microbiological methods, based on the growth of the microorganisms in a suitable culture medium. Over the past two years at the University of Malaga, we have implemented a new laboratory experiment for undergraduate chemistry and biochemistry students. In this experiment, students detected bacterial contamination in water by quantifying ATP with the luciferase-catalyzed reaction. The experiment was successfully implemented in two different formats, either as a full project developed by students throughout the entire duration of the academic course, or as a short protocol, carried out in a single laboratory session. Between them, a whole range of intermediate options could be arranged by educators to suit their course requirements and the learning objectives to be achieved by students.

Food-Borne Bacteria Associated with Contaminated Fishes: A Brief Review

Fish is considered a good source of protein and is consumed in many countries. Fish is a source of high protein giving approximately 16% of animal protein taken up by world’s population. Fish consist of high nutritional values like essential fatty acids, low saturated fat and omega-3 fatty acid which cannot be produced by human body. Majority of fish species resides in water, some burry themselves in mud and carry bacteria from into gut and skin. Microbiological contamination of fish is dependent on condition of water source. The normal flora of fish is constantly affected by bacterial contamination of water, contamination from wastewater and from sediments. The ingestion of contaminated fish and its products leads to foodborne infections, hence the occurrence of fish pathogens increase alarm about the product safety issue. These foodborne infections may arise from other sources like improper handling, storage, packaging and consumption of raw fish. Many people acquire infection by contact during handling of water, and by contact with other elements of fish living environment.

Safety Analysis of Freshwater Fish

The results presented in this paper demonstrate that the microbial population in the hydroecosystem has seasonal variations. The bacterial contamination of water and fish in November was 140 and 11 times less than in July respectively. It was found that fish caught in natural reservoirs in the autumn-winter period had different dynamics in the development of postmortem changes in comparison with those caught in the summer period. Postmortem secretion of mucus was not as pronounced in autumn-winter as in summer. Postmortem rigidity on the contrary was pronounced; gill covers were tightly fitting; and spinal muscles were tensed and of dense texture. Storing fresh river fish at a temperature of 3-5°C for 24 hours did not lead to a change in sensory evaluation. Physic-chemical indicators corresponded to the values characterizing fresh, healthy fish. During storage, the bacterial contamination of fish increased by more than 100 times, while the maximum permissible number of microorganisms (5.0 × 104 CFU / g) was not exceeded.
 Keywords: fish, microbiological control, organoleptic and physic-chemical indicators

Detection of Bacterial Contamination in Dental Unit Water Lines and Testing the Effectiveness of Disinfectants against these Contaminants

Aim: Contaminated dental unit water lines (DUWLs) are a possible source for spreading microorganisms in dental practices. The aim of this study was to detect the bacterial contamination of dental unit water and investigate the effectiveness of the disinfectants.
 Methodology: Bacterial contamination was detected by a) using bacterial culture of heterotrophic bacteria, total coliforms and Pseudomonas aeruginosa and b) Scanning electron microscopy (SEM) of DUWLs tube. Subsequently, dentists were suggested to treat the DUWLs with disinfectants to eradicate bacterial contaminants and its effectiveness was tested after three months.
 Results: Bacterial contamination of the water samples ranged from not detected to 2.38×106 CFU/mL. Out of 34 DUWLs water samples tested, 30 (88.24%) samples exceeded the Centers for Disease Control and Prevention (CDC) and Environmental Protection Agency (EPA) recommended threshold of ≤500 CFU /mL, whereas only 4 (11.76%) samples met the standards. Contamination by total coliforms and P. aeruginosa was detected in 52.94% and 64.7% of samples respectively. SEM displayed a dense biofilm on DUWLs tubing confirming the bacterial contamination. The intervention for disinfection of DUWLs resulted more than 50% samples with acceptable bacterial count in test performed after three months.
 Conclusion: The high rate of bacterial contamination of dental unit water highlights the need to disinfect and monitor the quality of DUWLs periodically.

A Whole-Cell Biosensor for Point-of-Care Detection of Waterborne Bacterial Pathogens.

Water contamination by pathogenic bacteria is a major public health concern globally. Monitoring bacterial contamination in water is critically important to protect human health, but this remains a critical challenge. Engineered whole-cell biosensors created through synthetic biology hold great promise for rapid and cost-effective detection of waterborne pathogens. In this study, we created a novel whole-cell biosensor to detect water contamination by Pseudomonas aeruginosa and Burkholderia pseudomallei, which are two critical bacterial pathogens and are recognized as common causative agents for waterborne diseases. The biosensor detects the target bacterial pathogens by responding to the relevant quorum sensing signal molecules. Particularly, this study constructed and characterized the biosensor on the basis of the QscR quorum sensing signal system for the first time. We first designed and constructed a QscR on the basis of the sensing module in the E.coli host cell and integrated the QscR sensing module with a reporting module that expressed an enhanced green fluorescent protein (EGFP). The results demonstrated that the biosensor had high sensitivity in response to the quorum sensing signals of the target bacterial pathogens. We further engineered a biosensor that expressed a red pigment lycopene in the reporting module to produce a visible signal readout for the pathogen detection. Additionally, we investigated the feasibility of a paper-based assay by immobilizing the lycopene-based whole-cell biosensor on paper with the aim to build a prototype for developing portable detection devices. The biosensor would provide a simple and inexpensive alternative for timely and point-of-care detection of water contamination and protect human health.