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This study was conducted to evaluate the effect of aerosol generation, relative humidity, and method of sampling on the culturability of the vegetative bacteria Pantoea agglomerans (P. agglomerans) formerly known as Erwinia herbicola. This research has relevance both for the use of this organism as a biowarfare simulant and for bioaerosol exposure assessment and public health. The culturability of P. agglomerans was tested using a test chamber against two generating systems (Collison and Bubble nebulizers), two sampling systems (the all-glass impinger (AGI-30), and the BioSampler), three collection media (water, TSB, and PBS) and across a range of humidities. Results indicated that the Bubble nebulizer was 15% more efficient in generating viable P. agglomerans counts (p ≤ 0.05). No difference was observed in overall efficiency between sampling methods (p > 0.05). However, as a collection media, PBS was observed to yield higher (p ≤ 0.01) viable counts compared to sterile deionized water. Relative humidity was found to strongly influence airborne P. agglomerans culturability. Culturable P. agglomerans was below the limit of detection for RH < 15% and then increased in a log-linear fashion to humidities of 75%. This research will help identify optimal means for evaluation of environmentally sensitive airborne bacteria for purposes of exposure assessment and public health as well as homeland security. [ABSTRACT FROM AUTHOR]

Examines the association of the foodborne outbreak of gastroenteritis with norwalk-like viruses (NLV) in Texas. Etiology of acute gastroenteritis; Development of the reverse-transcriptase polymerase chain reaction; Identification of NLV by immune electron microscopy.

Abstract: As a result of the widespread use of antibiotics in large-scale U.S. poultry production, a significant proportion of Salmonella strains recovered from conventional poultry farms and retail poultry products express antibiotic resistance. We evaluated whether large-scale poultry farms that transitioned from conventional to organic practices and discontinued antibiotic use were characterized by differences in the prevalence of antibiotic-resistant Salmonella compared to farms that maintained conventional practices. We collected poultry litter, water and feed samples from 10 newly organic and 10 conventional poultry houses. Samples were analyzed for Salmonella using standard enrichment methods. Isolates were confirmed using standard biochemical tests and the Vitek®2 Compact System. Antimicrobial susceptibility testing was performed by Sensititre® microbroth dilution. Data were analyzed using Fisher's exact test and generalized linear mixed models. We detected Salmonella in both conventional and newly organic poultry houses. Salmonella Kentucky was the predominant serovar identified, followed by S. Orion, S. Enteritidis, S. Gostrup and S. Infantis. Among S. Kentucky isolates (n=41), percent resistance was statistically significantly lower among isolates recovered from newly organic versus conventional poultry houses for: amoxicillin–clavulanate (p =0.049), ampicillin (p =0.042), cefoxitin (p =0.042), ceftiofur (p =0.043) and ceftriaxone (p =0.042). Percent multidrug resistance (resistance to ≥3 antimicrobial classes) was also statistically significantly lower among S. Kentucky isolates recovered from newly organic poultry houses (6%) compared to those recovered from conventional houses (44%) (p =0.015). To our knowledge, these are the first U.S. data to show immediate, on-farm changes in the prevalence of antibiotic-resistant Salmonella when antibiotics are voluntarily withdrawn from large-scale poultry facilities in the United States. [Copyright &y& Elsevier]

• First large-scale peer-reviewed investigation of PFAS in U.S. bottled water. • PFAS were detected in 39/101 uniquely labelled bottled water products. • Ultrashort-chain perfluoropropanoic acid (PFPrA) comprised 42% of detected PFAS mass. • Reverse osmosis-treated water contained less PFAS than other bottled water products. Per- and polyfluoroalkyl substances (PFAS) are compounds of emerging concern due to their persistence in the global water cycle and detection in drinking water sources. However, PFAS have been poorly studied in bottled water, especially in the United States. This study investigated the occurrence of PFAS and related factors in 101 uniquely labelled bottled water products for sale in the U.S. Products were screened for 32 target PFAS by solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). Fifteen of 32 measured analytes were detected, consisting primarily of C3-C10 perfluorocarboxylic acids (PFCA) and C3-C6 and C8 perfluorosulfonic acids (PFSA). PFAS were detected above method detection limits in 39/101 tested products. The Σ 32 PFAS concentrations detected were 0.17–18.87 ng/L with a median of 0.98 ng/L; 97% of samples were below 5 ng/L. PFCA (83%) and short-chain perfluoroalkyl acids (PFAA) containing 5 or less CF 2 groups (67%) were more prevalent on a mass basis than PFSA and longer-chain PFAA, respectively. Ultrashort-chain PFPrA, measured for the first time in bottled water, accounted for the greatest individual fraction of detected PFAS mass (42%) and was found almost exclusively in products labeled as Spring water. Purified water products contained significantly less PFAS than Spring water products, which was attributed to the use of reverse osmosis (RO) treatment in the majority of Purified waters (25/35) compared to Spring waters (1/45). RO-treated products contained significantly lower Σ 32 PFAS, long-chain, short-chain, and PFPrA concentrations than products without RO. Although no enforceable PFAS regulations exist for bottled water in the U.S., the finding that some products approach levels of concern justify a framework for monitoring PFAS in bottled water production. [Display omitted] [ABSTRACT FROM AUTHOR]

Organoarsenicals are commonly used for growth promotion in U.S. poultry production. Susceptibilities to arsenite, arsenate, and the organoarsenical roxarsone were measured in 251 Campylobacter isolates from conventional and antimicrobial-free retail poultry products. Isolates from conventional poultry products had significantly higher roxarsone MICs (z = 8.22; P < 0.0001). [ABSTRACT FROM AUTHOR]

Over the past two decades, the incidence of legionellosis has been steadily increasing in the United States though there is noclear explanation for the main factors driving the increase. While legionellosis is the leading cause of waterborne outbreaks in the US, most cases are sporadic and acquired in community settings where the environmental source is never identified. This scoping review aimed to summarise the drivers of infections in the USA and determine the magnitude of impact each potential driver may have. A total of 1,738 titles were screened, and 18 articles were identified that met the inclusion criteria. Strong evidence was found for precipitation as a major driver, and both temperature and relative humidity were found to be moderate drivers of incidence. Increased testing and improved diagnostic methods were classified as moderate drivers, and the ageing U.S. population was a minor driver of increasing incidence. Racial and socioeconomic inequities and water and housing infrastructure were found to be potential factors explaining the increasing incidence though they were largely understudied in the context of non-outbreak cases. Understanding the complex relationships between environmental, infrastructure, and population factors driving legionellosis incidence is important to optimise mitigation strategies and public policy.

Purpose of Review: This review examines the effectiveness of drinking water regulations to inform public health during extreme precipitation events. This paper estimates the vulnerability of specific populations to flooding in their public water system, reviews the literature linking precipitation to waterborne outbreaks, examines the role that Safe Drinking Water Act and Public Notification (PN) Rule have in public health emergencies, and reviews the effectiveness of the PN Rule during the 2017 Hurricane Maria in Puerto Rico., Recent Findings: Public water systems in large metropolitan areas have substantial portions of their customer base at risk for a waterborne outbreak during a flooding event. The PN Rule are ambiguous for who is responsible for declaring a "waterborne emergency" following a natural disaster like Hurricane Maria. Revisions to the current PN Rule that mandate public notification and water quality sampling during extreme precipitation events are necessary to ensure the public is aware of their drinking water quality following these events.

Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches - Fairhope Beach, AL and Goddard Beach, RI - with nearby publicly-owned treatment works (POTWs) outfalls. F(+) coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand-water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand. The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Traveler's diarrhea (TD) is the most common infectious illness acquired by visitors to developing nations. The purpose of this study was to utilize molecular diagnostic techniques to determine the prevalence of norovirus (NoV) in TD occurring among visitors from the United States to Guatemala and Mexico. Stool samples (n = 54) were collected from 34 TD cases and analyzed for NoV by reverse transcription-PCR and oligoprobe confirmation. The overall prevalence of NoV was 65%. Interestingly, all NoV-positive stool samples were identified as genogroup I NoVs, and time spent at travel destinations was found to be an important factor in determining the frequency of infection (P = 0.003). Eleven NoV-positive stool samples also tested positive for enterotoxigenic Escherichia coli, indicating that dual infections with this leading bacterial cause of TD were very common. Results of this study suggest that NoV infection is a frequent occurrence among travelers to Mexico and Guatemala who experience episodes of TD. In addition, the simple molecular detection method utilized here will serve to facilitate more in-depth epidemiological studies of this emergent viral pathogen in travelers and other at-risk populations.