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1.
Acinetobacter spp. in food and drinking water - A review.
Carvalheira, A, Silva, J, Teixeira, P
Food microbiology. 2021;:103675
Abstract
Acinetobacter spp. has emerged as a pathogen of major public health concern due to their increased resistance to antibiotics and their association with a wide range of nosocomial infections, community-acquired infections and war and natural disaster-related infections. It is recognized as a ubiquitous organism however, information about the prevalence of different pathogenic species of this genus in food sources and drinking water is scarce. Since the implementation of molecular techniques, the role of foods as a source of several species, including the Acinetobacter baumannii group, has been elucidated. Multidrug resistance was also detected among Acinetobacter spp. isolated from food products. This highlights the importance of foods as potential sources of dissemination of Acinetobacter spp. between the community and clinical environments and reinforces the need for further investigations on the potential health risks of Acinetobacter spp. as foodborne pathogens. The aim of this review was to summarize the published data on the occurrence of Acinetobacter spp. in different food sources and drinking water. This information should be taken into consideration by those responsible for infection control in hospitals and other healthcare facilities.
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The role of biofilm in the development and dissemination of ubiquitous pathogens in drinking water distribution systems: an overview of surveillance, outbreaks, and prevention.
Hemdan, BA, El-Taweel, GE, Goswami, P, Pant, D, Sevda, S
World journal of microbiology & biotechnology. 2021;(2):36
Abstract
A variety of pathogenic microorganisms can survive in the drinking water distribution systems (DWDS) by forming stable biofilms and, thus, continually disseminating their population through the system's dynamic water bodies. The ingestion of the pathogen-contaminated water could trigger a broad spectrum of illnesses and well-being-related obstacles. These waterborne diseases are a significant concern for babies, pregnant women, and significantly low-immune individuals. This review highlights the recent advances in understanding the microbiological aspects of drinking water quality, biofilm formation and its dynamics, health issues caused by the emerging microbes in biofilm, and approaches for biofilm investigation its prevention and suppression in DWDS.
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3.
Arsenic exposure and non-carcinogenic health effects.
Martínez-Castillo, M, García-Montalvo, EA, Arellano-Mendoza, MG, Sánchez-Peña, LDC, Soria Jasso, LE, Izquierdo-Vega, JA, Valenzuela, OL, Hernández-Zavala, A
Human & experimental toxicology. 2021;(12_suppl):S826-S850
Abstract
Inorganic arsenic (iAs) exposure is a serious health problem that affects more than 140 million individuals worldwide, mainly, through contaminated drinking water. Acute iAs poisoning produces several symptoms such as nausea, vomiting, abdominal pain, and severe diarrhea, whereas prolonged iAs exposure increased the risk of several malignant disorders such as lung, urinary tract, and skin tumors. Another sensitive endpoint less described of chronic iAs exposure are the non-malignant health effects in hepatic, endocrine, renal, neurological, hematological, immune, and cardiovascular systems. The present review outlines epidemiology evidence and possible molecular mechanisms associated with iAs-toxicity in several non-carcinogenic disorders.
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4.
Fluoride in Drinking Water and Skeletal Fluorosis: a Review of the Global Impact.
Srivastava, S, Flora, SJS
Current environmental health reports. 2020;(2):140-146
Abstract
When safe and adequate exposure of an essential trace element is exceeded it becomes potentially toxic. Fluoride is one classic example of such a double edged sword which both plays a fundamental role in the normal growth and development of the body for example the consumption of levels between 0.5-1.0 ppm via drinking water is beneficial for prevention of dental caries but its excessive consumption leads to development of fluorosis. PURPOSE OF REVIEW The abundance of fluorine in the environment as well as in drinking water sources are the major contributors to fluorosis. It is a serious public health concern as it is a noteworthy medical problem in 24 nations including India yet the threat of fluorosis has not been rooted out. The review focuses on recent findings related to skeletal fluorosis and role of oxidative stress in its development. The fluoride mitigation strategies adopted in recent years are also discussed. RECENT FINDINGS BASED ON CASE STUDIES Recent findings revealed that consumption of fluoride at concentrations of 1.5 ppm is majorly responsible for skeletal fluorosis. The sampling from rural areas showed that 80% villages are having fluoride concentrations more than the WHO permissible limits and people residing in such areas are affected by the skeletal fluorosis and also in the regions of Africa and Asia endemic fluorosis have been accounted in the majority of the region affecting approximately 100 million people. Various mitigation programmes and strategies have been conducted all over the world using defluoridation. Fluorosis is a slow and progressive malady affecting our body and a serious concern to be taken into consideration and to be dealt with effectively. The fluoride toxicity although reversible, is a slow process and the side effects lack treatment options. The treatment options available are either not approachable or affordable in the rural areas commonly suffering from the fluoride toxicity. No specific treatments are available to date to treat skeletal fluorosis affectively; therefore, prevention is one of most safest and best approach to fight fluorosis. The current review lays emphasis on the skeletal fluorosis and its prevalence in recent years. It also includes the recent findings as well as the current strategies related to combat skeletal fluorosis and provides findings that might be helpful to promote the research in the field of effective treatment for fluorosis as well as development of easy and affordable methods of fluoride removal from water.
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5.
Evaluation of different culture media for detection and quantification of H. pylori in environmental and clinical samples.
Hortelano, I, Moreno, Y, Vesga, FJ, Ferrús, MA
International microbiology : the official journal of the Spanish Society for Microbiology. 2020;(4):481-487
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Abstract
The objective of the present study was to establish the most suitable culture medium for the isolation of H. pylori from environmental and clinical samples. Ten different culture media were compared and evaluated. Four of them had been previously described and were modified in this study. The rest of the media were designed de novo. Three different matrices, tap water, wastewater, and feces, were inoculated with serial dilutions of H. pylori NCTC 11637 strain at a final concentration of 104 and 103 CFU/ml and the recovery rates were calculated. From inoculated tap water and wastewater samples, H. pylori colonies were recovered from four out of the analyzed culture media. When fecal samples were analyzed, the isolation of the pathogen under study was only possible from two culture media. Different optimal media were observed for each type of sample, even for wastewater and stool samples. Nevertheless, our results indicated that the combination of Dent Agar with polymyxin B sulfate did not inhibit the growth of H. pylori and was highly selective for its recovery, regardless of the sample origin. Thus, we propose the use of this medium as a diagnostic tool for the isolation of H. pylori from environmental and clinical samples, as well as for epidemiological studies.
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6.
The effects of heavy metals on human metabolism.
Fu, Z, Xi, S
Toxicology mechanisms and methods. 2020;(3):167-176
Abstract
As technology continues to advance, heavy metals in drinking water have exceeded recommended limits from regulators around the world. The main source of human exposure to heavy metals is from contaminated drinking water. The effects of drinking water contaminated with heavy metals, such as arsenic, lead, nickel, cadmium and mercury, have gradually caught the attention of the relevant departments and personnel. It is well known that occupational exposure to heavy metals occurs as a result of using these metals in a variety of industrial processes in and/or a variety of materials, including color pigments and alloys. A series of adverse effects on human metabolism has resulted from exposure to heavy metal-contaminated drinking water, which has been recorded from around the world. The general mechanism of heavy metal toxicity is through the production of reactive oxygen species, the appearance of oxidative damage, and subsequent adverse effects on health. Therefore, water contaminated with heavy metals causes high morbidity and mortality worldwide. In order to address concern regarding the health effects of different heavy metals, this paper reviews its sources, distribution and effects of heavy metal on human metabolism.HIGHLIGHTSThe accumulation of heavy metals such as lead, arsenic, mercury, cadmium and nickel will destroy the main metabolic process of human body.Redox reactions in biological systems are caused by carcinogenic metal ions such as nickel and arsenic. The free radicals produced by these reactions cause oxidative damage to proteins and DNA.The accumulation of heavy metals eventually produces reactive oxygen species that can cause oxidative stress, which may lead to the production of various diseases.
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Microorganisms populating the water-related indoor biome.
Novak Babič, M, Gostinčar, C, Gunde-Cimerman, N
Applied microbiology and biotechnology. 2020;(15):6443-6462
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Abstract
Modernisation of our households created novel opportunities for microbial growth and thus changed the array of microorganisms we come in contact with. While many studies have investigated microorganisms in the air and dust, tap water, another major input of microbial propagules, has received far less attention. The quality of drinking water in developed world is strictly regulated to prevent immediate danger to human health. However, fungi, algae, protists and bacteria of less immediate concern are usually not screened for. These organisms can thus use water as a vector of transmission into the households, especially if they are resistant to various water treatment procedures. Good tolerance of unfavourable abiotic conditions is also important for survival once microbes enter the household. Limitation of water availability, high or low temperatures, application of antimicrobial chemicals and other measures are taken to prevent indoor microbial overgrowth. These conditions, together with a large number of novel chemicals in our homes, shape the diversity and abundance of indoor microbiota through constant selection of the most resilient species, resulting in a substantial overlap in diversity of indoor and natural extreme environments. At least in fungi, extremotolerance has been linked to human pathogenicity, explaining why many species found in novel indoor habitats (such as dishwasher) are notable opportunistic pathogens. As a result, microorganisms that often enter our households with water and are then enriched in novel indoor habitats might have a hitherto underestimated impact on the well-being of the increasingly indoor-bound human population. KEY POINTS Domestic environment harbours a large diversity of microorganisms. Microbiota of water-related indoor habitats mainly originates from tap water. Bathrooms, kitchens and household appliances select for polyextremotolerant species. Many household-related microorganisms are human opportunistic pathogens.
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Microcystin Incidence in the Drinking Water of Mozambique: Challenges for Public Health Protection.
Tamele, IJ, Vasconcelos, V
Toxins. 2020;(6)
Abstract
Microcystins (MCs) are cyanotoxins produced mainly by freshwater cyanobacteria, which constitute a threat to public health due to their negative effects on humans, such as gastroenteritis and related diseases, including death. In Mozambique, where only 50% of the people have access to safe drinking water, this hepatotoxin is not monitored, and consequently, the population may be exposed to MCs. The few studies done in Maputo and Gaza provinces indicated the occurrence of MC-LR, -YR, and -RR at a concentration ranging from 6.83 to 7.78 µg·L-1, which are very high, around 7 times above than the maximum limit (1 µg·L-1) recommended by WHO. The potential MCs-producing in the studied sites are mainly Microcystis species. These data from Mozambique and from surrounding countries (South Africa, Lesotho, Botswana, Malawi, Zambia, and Tanzania) evidence the need to implement an operational monitoring program of MCs in order to reduce or avoid the possible cases of intoxications since the drinking water quality control tests recommended by the Ministry of Health do not include an MC test. To date, no data of water poisoning episodes recorded were associated with MCs presence in the water. However, this might be underestimated due to a lack of monitoring facilities and/or a lack of public health staff trained for recognizing symptoms of MCs intoxication since the presence of high MCs concentration was reported in Maputo and Gaza provinces.
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Uranium in drinking water: a public health threat.
Bjørklund, G, Semenova, Y, Pivina, L, Dadar, M, Rahman, MM, Aaseth, J, Chirumbolo, S
Archives of toxicology. 2020;(5):1551-1560
Abstract
Uranium (U) has no known essential biological functions. Furthermore, it is well known for its toxicity, radioactivity, and carcinogenic potency. Impacts on human health due to U exposure have been studied extensively by many researchers. Chronic exposure to low-level U isotopes (radionuclides) may be interlinked with cancer etiology and at high exposure levels, also kidney disease. Other important issues covered U and fertilizers, and also U in soils or human tissues as an easily measurable indicator element in a pathophysiological examination. Furthermore, phosphate fertilization is known as the important source of contamination with U in the agricultural land, mainly due to contamination in the phosphate rock applied for fertilizer manufacture. Therefore, long-term usage of U-bearing fertilizers can substantially increase the concentration of U in fertilized soils. It should also be noted that U is an active redox catalyst for the reaction between DNA and H2O2. This review is aimed to highlight a series on various hydro-geochemical aspects in different water sources and focused on the comparison of different U contents in the drinking water sources and presentation of data in relation to health issues.
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A novel method: using an adenosine triphosphate (ATP) luminescence-based assay to rapidly assess the biological stability of drinking water.
Zhang, K, Pan, R, Zhang, T, Xu, J, Zhou, X, Yang, Y
Applied microbiology and biotechnology. 2019;(11):4269-4277
Abstract
The rapid and credible evaluations of the microbial stability of a drinking water distribution system (DWDS) are of great significance for ensuring the safety of drinking water and predicting microbial pollution. Conventional biostability assessment methods mainly focus on bacterial regrowth or evaluation of the level of nutrients that support bacterial regrowth. However, such methods are time-consuming and have many limitations. An adenosine triphosphate (ATP) assay can rapidly measure all active microorganisms and is known to be a useful method to assess the microbial activity of drinking water. The measurement of ATP has been used for more than a decade in the field of drinking water research. This article reviews the application of an ATP luminescence-based method to assess the biostability of drinking water and discusses the feasibility of ATP measurement as a parameter for quickly evaluating this criterion. ATP measurement will help researchers and water managers better monitor the biological stability of drinking water from the source to the consumer's tap. This review covers the: (1) principle and application of the ATP measurement in drinking water quality assessment; (2) comparison of the merits and demerits of several methods for evaluating the biostability of drinking water; (3) discussions on using ATP measurement in evaluating biostability; and (4) improvements in the use of ATP measurement in evaluating biostability. At the end of this review, recommendations were given for better application of the ATP measurement as a parameter for monitoring the microbial quality of drinking water.