Aeromonas caviae strain induces Th1 cytokine response in mouse intestinal tract.

Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus. Microarray profiling of murine small intestinal extracts, 24 h after oral infection with an A. caviae strain, provides evidence of a Th1 type immune response. A large number of gamma-interferon (gamma-IFN) induced genes are up-regulated as well as several tumor necrosis factor-alpha (TNF-alpha) transcripts. Aeromonas caviae has always been considered an opportunistic pathogen because it lacks obvious virulence factors. This current effort suggests that an A. caviae strain can colonize the murine intestinal tract and cause what has been described by others as a dysregulatory cytokine response. This response could explain why a number of diarrheal waterborne disease cases have been attributed to A. caviae even though it lacks obvious enteropathogenic properties.

Correlation between ERMI values and other moisture and mold assessments of homes in the American Healthy Homes Survey.

The main objective of this study was to evaluate the correlation between the Environmental Relative Moldiness Index (ERMI) values in the Department of Housing and Urban Development American Healthy Homes Survey (AHHS) homes and an alternative analysis frequently used in mold investigations, i.e., the inspector's "walk-through" assessment of visual or olfactory evidence of mold combined with occupant's answers to a questionnaire about mold odors and moisture. Homes in the highest ERMI quartile were in agreement with visual inspection and/or occupant assessment 48% of the time but failed to detect the mold in 52% of the fourth quartile homes. In about 7% of lowest ERMI quartile homes, the inspection and occupant assessments overestimated the mold problem. The ERMI analysis of dust from homes may be useful in finding hidden mold problems. An additional objective was to compare the ERMI values in inner city east-Baltimore homes, where childhood asthma is common, to the AHHS randomly selected homes.

Screening tools to estimate mold burdens in homes.

OBJECTIVE: The objective of this study was to develop screening tools that could be used to estimate the mold burden in a home which would indicate whether more detailed testing might be useful. METHODS: Two possible screening methods were considered for mold analysis: use of vacuum cleaner bag dust rather than the standard protocol dust samples and reducing the number of molds needed to be quantified resulting in the creation of an alternative mold burden scale. RESULTS: Vacuum bag dust analysis placed the estimate of mold burden into the upper or lower half of the Environmental Relative Moldiness Index scale. Mold burdens estimated by only 12 species produced an index, the American Relative Moldiness Index, with a correlation of rho = 0.80 with the Environmental Relative Moldiness Index. CONCLUSIONS: Two screening tools were developed for estimating the mold burden in homes.

Higher Environmental Relative Moldiness Index (ERMIsm) values measured in Detroit homes of severely asthmatic children.

Sieved vacuum bag dust from the homes of 143 children in Detroit was analyzed by mold specific quantitative PCR (MSQPCR) and the Environmental Relative Moldiness Index (ERMIsm) was calculated for each home. Children living in these homes were grouped as non-asthmatic (n=83), moderately asthmatic (n=28) and severely asthmatic (n=32) based on prescription medication usage for their asthma management (none, occasional and daily, respectively). The mean ERMI for each group of homes was 6.2 for non-asthmatic, 6.3 for moderately asthmatic and 8.2 for severely asthmatic children. The ERMI values in the homes of severely asthmatic children were significantly greater compared to the non-asthmatics (p=0.04 in Wilcoxon Rank-sum test). Aspergillus niger and Aspergillus unguis were the primary mold species that distinguished severely asthmatic children's homes and non-asthmatic children's homes (p<0.05; Wilcoxon Rank-sum test). The determination of the home's ERMI values may aid in prioritizing home remediation efforts, particularly in those children who are at increased risk for asthma exacerbation.

Quantifying fungal viability in air and water samples using quantitative PCR after treatment with propidium monoazide (PMA).

A method is described to discriminate between live and dead cells of the infectious fungi Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Mucor racemosus, Rhizopus stolonifer and Paecilomyces variotii. To test the method, conidial suspensions were heat inactivated at 85 degrees C or held at 5 degrees C (controls) for 1 h. Polycarbonate filters (25 mm diameter, 0.8 microm pore size) were placed on "welled" slides (14 mm diameter) and the filters treated with either PBS or PMA. Propidium monoazide (PMA), which enters dead cells but not live cells, was incubated with cell suspensions, exposed to blue wavelength light-emitting diodes (LED) to inactivate remaining PMA and secure intercalation of PMA with DNA of dead cells. Treated cells were extracted and the live and dead cells evaluated with quantitative PCR (QPCR). After heat treatment and DNA modification with PMA, all fungal species tested showed an approximate 100- to 1000-fold difference in cell viability estimated by QPCR analysis which was consistent with estimates of viability based on culturing.

Investigating freshwater periphyton community response to uranium with phospholipid fatty acid and denaturing gradient gel electrophoresis analyses.

Periphyton communities can be used as monitors of ecosystem health and as indicators of contamination in lotic systems. Measures of biomass, community structure, and genetic diversity were used to investigate impacts of uranium (U) exposure on periphyton. Laboratory exposures of periphyton in river water amended with 238U were performed for 5 days, followed by 2 days of U depuration in unamended river water. Productivity as measured by biomass was not affected by concentrations up to 100 microg238U L(-1). Phospholipid fatty acid (PLFA) profiles and denaturing gradient gel electrophoresis (DGGE) banding patterns revealed no changes in community or genetic structure related to U exposure. We suggest that the periphyton community as a whole was not significantly impacted by exposures of 238U up to a concentration of 100 microgL(-1). These findings have significance for the assessment and prediction of U impacts on aquatic ecosystems.

Quantitative PCR analysis of molds in the dust from homes of asthmatic children in North Carolina.

The vacuum bag (VB) dust from the homes of 19 asthmatic children in North Carolina (NC) was analyzed by mold specific quantitative PCR. These results were compared to the analysis of the VB dust from 176 homes in the HUD, American Healthy Home Survey of homes in the US. The Environmental Relative Moldiness Index (ERMI) was calculated for each of the homes. The mean and standard deviation (SD) of the ERMI values in the homes of the NC asthmatic children was 16.4 (6.77), compared to the HUD survey VB ERMI value mean and SD of 11.2 (6.72), and was significantly greater (t-test, p = 0.003) in the NC asthmatic children's homes. The molds Chaetomium globosum, Aspergillus fumigatus, and the Eurotium Group were the primary species in the NC homes of asthmatics, making the ERMI values significantly higher (p < 0.02 for each). Vacuum bag dust analysis may be a useful method for estimating the mold burden in a home.

Development of an Environmental Relative Moldiness index for US homes.

OBJECTIVE: The objective of this study was to establish a national relative moldiness index for homes in the United States. METHODS: As part of the Housing and Urban Development's American Healthy Homes Survey, dust samples were collected by vacuuming 2 m in the bedrooms plus 2 m in the living rooms from a nationally representative 1096 homes in the United States using the Mitest sampler. Five milligrams of sieved (300 mum pore, nylon mesh) dust was analyzed by mold-specific quantitative polymerase chain reaction for the 36 indicator species in 1096 samples. RESULTS: On the basis of this standardized national sampling and analysis, an "Environmental Relative Moldiness Index" was created with values ranging from about -10 to 20 or above (lowest to highest). CONCLUSIONS: The Environmental Relative Moldiness Index scale may be useful for home mold-burden estimates in epidemiological studies.

Comparison of mold concentrations quantified by MSQPCR in indoor and outdoor air sampled simultaneously.

Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of the 36 mold species in indoor and outdoor air samples that were taken simultaneously for 48 h in and around 17 homes in Cincinnati, Ohio. The total spore concentrations of 353 per m(3) of indoor air and 827 per m(3) of outdoor air samples were significantly different (por=0.5). These results suggest that interpretation of the meaning of short-term (<48 h) mold measurements in indoor and outdoor air samples must be made with caution.

Evaluation of early life stage fall chinook salmon exposed to hexavalent chromium from a contaminated groundwater source.

We conducted a laboratory evaluation to assess the risk to early life stage (i.e., eyed egg to swim up) fall Chinook salmon (Oncorhynchus tshawytscha) for exposure to hexavalent chromium from a contaminated groundwater source. Local populations of fall Chinook salmon were exposed to Hanford Site source groundwater that was diluted with Columbia River water. Specific endpoints included survival, development rate, and growth. Tissue burdens of fish were also measured to estimate uptake and elimination rates of chromium. Survival, development, and growth of early life stage fall Chinook salmon were not adversely affected by extended exposures (i.e., 98 day) to hexavalent chromium ranging from 0.79 to 260 microg/l. Survival for all treatment levels and controls exceeded 98% at termination of the test. In addition, there were no differences among the mean lengths and weights of fish among all treatment groups. Whole-body concentrations of chromium in early life stage fall Chinook salmon had a typical dose-response pattern; i.e., those subjected to highest exposure concentrations and longest exposure intervals had higher tissue concentrations. Given the spatial extent of chromium concentrations at the Hanford Site, and the dynamics of the groundwater-river water interface, the current cleanup criterion of 10 microg/l chromium appear adequate to protect early life stage fall Chinook salmon. These findings, together with previous research indicate low risk to these populations.

Relative moldiness index as predictor of childhood respiratory illness.

The results of a traditional visual mold inspection were compared to a mold evaluation based on the Relative Moldiness Index (RMI). The RMI is calculated from mold-specific quantitative PCR (MSQPCR) measurements of the concentration of 36 species of molds in floor dust samples. These two prospective mold evaluations were used to classify the mold condition in 271 homes of infants. Later, the development of respiratory illness was measured in the infants living in these homes and the predictive value of each classification system was evaluated. The binary classification of homes as either moldy or non-moldy by on-site visual home inspection was not predictive of the development of respiratory illness (wheeze and/or rhinitis) (P=0.27). Conversely, a method developed and validated in this paper, using the RMI index fit to a logistic function, can be used to predict the occurrence of illness in homes and allows stake-holders the choice among various levels of risk.

Specific molds associated with asthma in water-damaged homes.

OBJECTIVE: We sought to determine if specific molds were found in significantly higher concentrations in the water-damaged homes of asthmatic children compared with homes with no visible water damage. METHODS: The mold concentrations in the dust in asthmatic children's bedrooms in water-damaged homes (N = 60) and control homes (N = 22) were measured by mold-specific quantitative polymerase chain reaction. RESULTS: Two molds, Scopulariopsis brevicaulis and Trichoderma viride, had significantly (P < 0.05) higher concentrations in asthmatics' homes compared with control homes and three other molds (Penicillium crustosum group, Stachybotrys chartarum, and Wallemia sebi) had P values <0.1. CONCLUSIONS: A relative moldiness index was developed to predict the likely development of asthma in water-damaged homes in Cleveland.