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result(s) for
"Sinclair, Ryan G."
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Microbial contamination analysis of drinking water from bulk dispensers and fast-food restaurants in the Eastern Coachella Valley, California
by
Hile, Thomas Dama
,
Sinclair, Ryan G.
,
Dunbar, Stephen G.
in
Bacteria
,
Beverages
,
Biological contamination
2023
Safe drinking water is a fundamental requirement for human life. The deterioration of water quality primarily involves microbiological hazards, since most evident water-related health problems are the result of microbial contamination. The aim of this study was to evaluate the microbial contamination of drinking water from three sources: water vending machines (WVMs), soda fountains (SFs), and tap water (TW) in the Eastern Coachella Valley (ECV) using physico-chemical parameters, conventional cultivable methods, including IDEXX technology and molecular methods. A total of 72 samples were analyzed and results indicated heterotrophic plate counts (HPCs) bacteria in 20% of samples from WVMs, 25% of samples from SFs, 33.3% of TW samples, and 76% of swab samples. Results also demonstrated 20% of WVM, 88% of swab samples, 41% of SF, and 50% of TW samples had total coliforms. Our qPCR indicated the presence of genetic materials of all six selected microorganisms (Salmonella spp, Listeria monocytogenes, Pseudomonas aeruginosa, Campylobacter jejuni, Escherichia coli, Enterococcus faecalis) used as indicators of pathogenic microorganisms in water from WVMs, SFs, and TW, and were represented at different concentrations and predominance.
Journal Article
Microbial contamination of drinking water from vending machines of Eastern Coachella Valley
by
Sinclair, Ryan G.
,
Hile, Thomas D.
,
Dunbar, Stephen G.
in
Biological contamination
,
Chemical contaminants
,
Chlorine
2021
Drinking water quality from sources other than tap water is increasingly becoming a source of concern in many communities. Communities in the Eastern Coachella Valley (ECV), Riverside County, California, USA have raised concerns regarding bulk drinking water from water vending machines (WVMs) found in public vendors. To address concerns, we conducted microbiological contamination assessments of drinking water from WVMs in the ECV using heterotrophic plate counts (HPC), the presence of total coliforms using IDEXX technology, and real-time PCR (qPCR). We also measured temperature, pH, electrical conductivity, and free chlorine concentration. Twenty-five WVMs were sampled by using positively charged NanoCeram® filters in the field. Results indicated 32% of WVMs had total coliforms, and 21% had HPC above Environmental Protection Agency (EPA) requirements. Through qPCR, we found 81% of WVMs had Salmonella spp., Listeria monocytogenes, and Campylobacter jejuni, 76% had Enterococcus faecalis, and 90% had Pseudomonas aeruginosa. Results indicated most WVM samples we collected contained genetic material of pathogenic microorganisms and therefore, did not meet EPA drinking water standards. There is an urgency to enforce WVM maintenance through drain flushing, spigot cleaning, rust removal, filter replacement, and limits to physico-chemical parameters.
Journal Article
Microbiological quality of drinking water from water dispensers
by
Dunbar, Stephen G
,
Leal, Raeann
,
Sinclair, Ryan G
in
Bottled water
,
Chemical contaminants
,
Compliance
2025
The consumption of drinking water from sources other than tap water, such as bottled water or water dispenser (WD) machines, is increasing worldwide, driven by consumer preferences for health, convenience, and taste. This trend raises concerns about potential microbial contamination and associated public health risks. In this review, we aimed to comprehensively analyze the scientific literature on microbial contamination in water dispenser machines, evaluate the quality of dispensed water, identify sources of contamination and potential health implications, and propose solutions to mitigate these risks. We conducted a comprehensive search of scientific databases, including PubMed, EBSCO, and Google Scholar, using relevant keywords related to water dispenser contamination. Abstracts and methods of identified studies were critically appraised to ensure rigorous assessment of microbial contamination. Our analysis of approximately 70 studies revealed that despite consumer perceptions of health benefits, water dispenser machines can harbor higher levels of microbial contamination than the tap water sources supplying them. This review underscores the potential public health risks associated with water dispenser use, and highlights the need for increased vigilance, regular maintenance, and further research to ensure the safety of dispensed water.
Journal Article
Assessment of tap water quality in mobile homes in the Eastern Coachella Valley, California
2022
Very few studies have been undertaken on water quality from mobile homes, with most information coming from press and policy reports suggesting that people living in mobile homes in the US have poor water quality. Our goal was to evaluate resident exposure to microbes at the point of use of tap water sourced from the Oasis Mobile Homes Park (OMHP), using physico-chemical parameters, concentrations of target cultivatable microbes, and quantitative polymerase chain reaction (qPCR) analyses. In this study, we sampled 15 mobile homes (MHs) and found arsenic concentrations to be 4–8 times above the acceptable EPA standard of 10 ppm. Our qPCR demonstrated high concentrations of gene targets for Salmonella spp., L . monocytogenes , P . aeruginosa , C . jejuni , E . faecalis , and E . coli in one or more of our sampled mobile homes. Except for MH4, which had the highest concentration of L . monocytogenes and E . faecalis , all MHs had different predominant microorganisms. Based on the physico-chemical parameters and our microbiological analysis, we conclude that drinking water from MH taps in the OMHP is unsafe for consumption.
Journal Article
Pathogens and Indicators in United States Class B Biosolids: National and Historic Distributions
by
Pepper, Ian L
,
Brooks, John P
,
Gurian, Patrick L
in
Adenoviruses
,
anaerobic digestion
,
Arizona
2010
This paper reports on a major study of the incidence of indicator organisms and pathogens found within Class B biosolids within 21 samplings from 18 wastewater treatment plants across the United States. This is the first major study of its kind since the promulgation of the USEPA Part 503 Rule in 1993, and includes samples before and after the Part 503 Rule was promulgated. National distributions collected between 2005 and 2008 show that the incidence of bacterial and viral pathogens in Class B mesophilic, anaerobically digested biosolids were generally low with the exception of adenoviruses, which were more prevalent than enteric viruses. No Ascaris ova were detected in any sample. In contrast, indicator organism numbers were uniformly high, regardless of whether they were bacteria (fecal coliforms) or viruses (phage). Indicators were not correlated with pathogen loads. Historic distributions were collected between 1988 and 2006 at one location in Tucson, AZ. By comparing data collected before and after 1993, the influence of the USEPA Part 503 Rule on indicator and pathogen levels within Class B biosolids can be inferred. In general, the bacterial indicators total and fecal coliforms decreased from the 1980s to present. Enteric virus concentrations after 1993 are much lower than those reported in other studies in the 1980s, although our values from 1988 to 1993 are not significantly different from our values obtained from 1994 to 2006. Presumably this is due to better and more consistent treatment of the wastewater, illustrating that the Part 503 Rule has been effective in reducing public exposure to pathogens relative to 17 yr ago. The percent reduction of both indicators and pathogens during anaerobic mesophilic digestion was between 94 and 99% for all organisms, illustrating that such treatment is effective in reducing pathogen loads.
Journal Article
Assessment of the Potential for Cross-contamination of Food Products by Reusable Shopping Bags
2011
The purpose of this study was to assess the potential for cross-contamination of food products by reusable bags used to carry groceries. Reusable bags were collected at random from consumers as they entered grocery stores in California and Arizona. In interviews, it was found that reusable bags are seldom if ever washed and often used for multiple purposes. Large numbers of bacteria were found in almost all bags and coliform bacteria in half. Escherichia coli were identified in 8% of the bags, as well as a wide range of enteric bacteria, including several opportunistic pathogens. When meat juices were added to bags and stored in the trunks of cars for two hours, the number of bacteria increased 10-fold, indicating the potential for bacterial growth in the bags. Hand or machine washing was found to reduce the bacteria in bags by > 99.9%. These results indicate that reusable bags, if not properly washed on a regular basis, can play a role in the cross-contamination of foods. It is recommended that the public be educated about the proper care of reusable bags by means of printed instructions on the bags or through public service announcements. [PUBLICATION ABSTRACT]
Trade Publication Article
Efficacy of Treatment of Reusable Grocery Bags with Antimicrobial Silver to Reduce Enteric Bacteria
by
Sifuentes, Laura Y
,
Gerba, Charles P
,
Sinclair, Ryan G
in
Antimicrobial agents
,
Bacteria
,
Coliforms
2016
Reusable grocery bags are seldom washed in homes and can become contaminated with enteric bacteria during use in grocery shopping. The goal of this study was to evaluate the efficacy of a cloth fiber grocery bag impregnated with silver in controlling enteric bacteria and viruses in three different settings. The reusable grocery bags were evaluated for bacterial survival in the laboratory, for bacterial growth in the trunk of a car, and for bacterial contamination when used by volunteers over 4 months. In the laboratory, the treatment was found to reduce Escherichia coli, Salmonella Choleraesuis, and Staphylococcus aureus counts by more than 99.9% within two hours and the MS2 virus and murine norovirus by 99.5%. When placed in a car trunk during warm weather, the silver treatment was capable of reducing bacterial counts in bags containing meat juices even under conditions that ordinarily promoted growth of bacteria. After being distributed to 38 households in Southern California for use over 4 months, the bags were found to have significantly fewer coliforms than non-treated canvas bags. The major significance of these findings is that the broad antimicrobial properties of silver make it a useful component of commercially available reusable grocery bags.
Magazine Article
Liberal or Restrictive Transfusion Strategy in Aneurysmal Subarachnoid Hemorrhage
2025
In a trial involving patients with subarachnoid hemorrhage and anemia, liberal transfusion of red cells did not result in a lower risk of an unfavorable neurologic outcome than a more restrictive strategy.
Journal Article
11βHSD1 Inhibition with AZD4017 Improves Lipid Profiles and Lean Muscle Mass in Idiopathic Intracranial Hypertension
by
Hardy, Rowan S
,
Gilligan, Lorna C
,
Botfield, Hannah
in
11-beta-Hydroxysteroid Dehydrogenase Type 1 - antagonists & inhibitors
,
11β-Hydroxysteroid dehydrogenase
,
Adolescent
2021
Abstract
Background
The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) determines prereceptor metabolism and activation of glucocorticoids within peripheral tissues. Its dysregulation has been implicated in a wide array of metabolic diseases, leading to the development of selective 11β-HSD1 inhibitors. We examined the impact of the reversible competitive 11β-HSD1 inhibitor, AZD4017, on the metabolic profile in an overweight female cohort with idiopathic intracranial hypertension (IIH).
Methods
We conducted a UK multicenter phase II randomized, double-blind, placebo-controlled trial of 12-week treatment with AZD4017. Serum markers of glucose homeostasis, lipid metabolism, renal and hepatic function, inflammation and androgen profiles were determined and examined in relation to changes in fat and lean mass by dual-energy X-ray absorptiometry.
Results
Patients receiving AZD4017 showed significant improvements in lipid profiles (decreased cholesterol, increased high-density lipoprotein [HDL] and cholesterol/HDL ratio), markers of hepatic function (decreased alkaline phosphatase and gamma-glutamyl transferase), and increased lean muscle mass (1.8%, P < .001). No changes in body mass index, fat mass, and markers of glucose metabolism or inflammation were observed. Patients receiving AZD4017 demonstrated increased levels of circulating androgens, positively correlated with changes in total lean muscle mass.
Conclusions
These beneficial metabolic changes represent a reduction in risk factors associated with raised intracranial pressure and represent further beneficial therapeutic outcomes of 11β-HSD1 inhibition by AZD4017 in this overweight IIH cohort. In particular, beneficial changes in lean muscle mass associated with AZD4017 may reflect new applications for this nature of inhibitor in the management of conditions such as sarcopenia.
Journal Article
Demonstration of sub-3 ps temporal resolution with a superconducting nanowire single-photon detector
by
Xie Si
,
Shaw, Matthew D
,
Sinclair, Neil
in
Biomedical materials
,
Chemical compounds
,
Communications systems
2020
Improvements in temporal resolution of single-photon detectors enable increased data rates and transmission distances for both classical and quantum optical communication systems, higher spatial resolution in laser ranging, and observation of shorter-lived fluorophores in biomedical imaging. In recent years, superconducting nanowire single-photon detectors (SNSPDs) have emerged as the most efficient time-resolving single-photon-counting detectors available in the near-infrared, but understanding of the fundamental limits of timing resolution in these devices has been limited due to a lack of investigations into the timescales involved in the detection process. We introduce an experimental technique to probe the detection latency in SNSPDs and show that the key to achieving low timing jitter is the use of materials with low latency. By using a specialized niobium nitride SNSPD we demonstrate that the system temporal resolution can be as good as 2.6 ± 0.2 ps for visible wavelengths and 4.3 ± 0.2 ps at 1,550 nm.Knowledge about detection latency provides a guideline to reduce the timing jitter of niobium nitride superconducting nanowire single-photon detectors. A timing jitter of 2.6 ps at visible wavelength and 4.3 ps at 1,550 nm is achieved.
Journal Article