Asymptomatic Carriage of C. botulinum Type D/C in Broiler Flocks as the Source of Contamination of a Massive Botulism Outbreak on a Dairy Cattle Farm.

In winter 2018, a massive type D/C cattle botulism outbreak occurred on a mixed dairy and broiler farm in France. An investigation was conducted based on the hypothesis of asymptomatic carriage in poultry. We set out to identify the source of contamination of the dairy cattle and to monitor the contamination of broilers over time, including the hatchery delivering chicks to the farm. Environmental samples were collected on the farm during the cattle outbreak (n = 40), after the outbreak for three successive broiler flocks (n = 128), and once in the hatchery delivering the chicks (n = 58). These samples were analyzed using real-time PCR after an enrichment step to detect Clostridium botulinum type D/C. The results showed contamination in the manure from the broilers raised just before the onset of the cattle outbreak (5 + /5), as well as in some of the components of the cattle ration (3 + /17). This latter contamination is likely due to the use of the same tractor bucket to remove litter from the poultry house and to prepare the cattle ration on the same day. Contamination monitoring over several months revealed continuous asymptomatic carriage in the broilers (4 + /20 and 17 + /20 cloacal swabs in 2 successive flocks), a persistence of C. botulinum type D/C in the ventilation system of the poultry house (8 + /14), and contamination of the equipment coming from the hatchery used for delivering the chicks (3 + /18). Further investigations conducted in the hatchery demonstrated contamination in the hatchery by C. botulinum type D/C (6 + /58). Comparison of samples using a multilocus variable number tandem repeat analysis showed the same profile for samples collected on broilers, cattle and in the hatchery. This study highlighted the crucial role of the implementation of biosecurity measures in mixed farms to avoid cross-contamination between production units given the potential asymptomatic carriage of poultry. This study also revealed the contamination of the poultry hatchery. Further investigations are required to better understand the role of hatcheries in the epidemiology of animal botulism.

Managing irritable bowel syndrome: The impact of micro-physiotherapy.

Background Irritable bowel syndrome (IBS) has a complex pathology, high prevalence and large impact on patients' quality of life. As conventional therapy may yield unsatisfactory results, a more holistic approach may be desirable. The current study assessed the effect of micro-physiotherapy on the severity of IBS symptoms. Methods In a double-blind study, 61 recurrent IBS patients were randomised to two sessions of micro-physiotherapy or sham micro-physiotherapy. Inclusion criteria were the presence of ≥1 IBS symptom from abdominal pain, constipation, diarrhoea or bloating. Exclusion criteria were previous major intestinal surgery and the presence of chronic diseases. The mean patient age was 53.5±15.3 years. Micro-physiotherapy consisted of micro-palpatory examination to identify osteopathic lesions, followed by micro-massage to stimulate self-healing. The control group underwent a sham procedure. The presence and severity of symptoms was assessed at baseline and at 1-month follow-up by the same gastroenterologist. Results Two patients did not complete the study. There was a significant difference in percentage of patients that improved after the first session, at 74 % for the micro-physiotherapy group and 38 % for the sham group, respectively (p=0.005). After the second session, the initial improvement was maintained in both groups, although with no further gains, and the differences between the study groups remained significant (p=0.007). Conclusions Micro-physiotherapy significantly improves IBS symptoms and should be explored further for use in mainstream healthcare.

Carbonyl and nitrogen dioxide emissions from gasoline- and diesel-powered motor vehicles.

Carbonyls can be toxic and highly reactive in the atmosphere. To quantify trends in carbonyl emissions from light-duty (LD) vehicles, measurements were made in a San Francisco Bay area highwaytunnel bore containing essentially all LD vehicles during the summers of 1999, 2001, and 2006. The LD vehicle emission factor for formaldehyde, the most abundant carbonyl, did not change between 1999 and 2001, then decreased by 61 +/- 7% between 2001 and 2006. This reduction was due to fleet turnover and the removal of MTBE from gasoline. Acetaldehyde emissions decreased by 19 +/- 2% between 1999 and 2001 and by the same amount between 2001 and 2006. Absent the increased use of ethanol in gasoline after 2003, acetaldehyde emissions would have further decreased by 2006. Carbonyl emission factors for medium- (MD) and heavy-duty (HD) diesel trucks were measured in 2006 in a separate mixed-traffic bore of the tunnel. Emission factors for diesel trucks were higher than those for LD vehicles for all reported carbonyls. Diesel engine exhaust dominates over gasoline engines as a direct source of carbonyl emissions in California. Carbonyl concentrations were also measured in liquid-gasoline samples and were found to be low (< 20 ppm). The gasoline brands that contained ethanol showed higher concentrations of acetaldehyde in unburned fuel versus gasoline that was formulated without ethanol. Measurements of NO2 showed a yearly rate of decrease for LD vehicle emissions similar to that of total NOx in this study. The observed NO2/NOx ratio was 1.2 +/- 0.3% and 3.7 +/- 0.3% for LD vehicles and diesel trucks, respectively.

Speciated ambient carbonyls in Rio de Janeiro, Brazil.

Carbonyls in urban air continue to receive scientific and regulatory attention as toxic air contaminants and for their important role in photochemical smog. However, few data are available for speciated carbonyls in urban air. Ambient concentrations of up to 61 carbonyls have been measured in Rio de Janeiro, Brazil. The most abundant carbonyls were formaldehyde and acetaldehyde (study-averaged concentrations of 10.8 +/- 4.1 and 10.4 +/- 4.6 microg m(-3), respectively, in samples of 3-h duration collected from May to November 2000 at a downtown location during the morning vehicle commute) followed by acetone, 2-butanone, and benzaldehyde. Ambient concentrations of other carbonyls (except acetophenone) correlated well with those of acetaldehyde and of formaldehyde. This study examines the ambient acetaldehyde/ambient formaldehyde concentration ratio in Brazilian cities since the mid-1980s in the context of changes in Brazil's reliance on ethanol as a vehicle fuel. This ratio has begun to decrease in recent years due to fleet turnover and is likely to decrease further as older cars fueled with ethanol are replaced by lower-emitting models that run on a gasoline-ethanol blend. The carbonyls measured are ranked with respect to ozone formation potential (using MIR coefficients) and reaction with OH (using carbonyl-OH reaction rate constants). Ozone formation is dominated by formaldehyde (43% of total) followed by acetaldehyde (32%) and methylglyoxal (8%); other carbonyls each contributed < or = 4% of total. For reaction with OH, acetaldehyde ranks first closely followed by formaldehyde.

Airborne carbonyls from motor vehicle emissions in two highway tunnels.

Carbonyls (aldehydes and ketones) continue to receive scientific and regulatory attention as toxic air contaminants, mutagens, and carcinogens. Vehicle emissions are a major source of carbonyls in outdoor air, but information about the nature and magnitude of carbonyl emissions by motor vehicles is limited. The objective of this study was to identify speciated carbonyls emitted by motor vehicles under real-world, on-road conditions and to calculate on-road carbonyl emission factors. We collected air samples at the inlet and outlet of two highway tunnels, the Caldecott Tunnel near San Francisco and the Tuscarora Mountain Tunnel in Pennsylvania. At the Caldecott Tunnel, the fleet consisted almost entirely of light-duty (LD) vehicles that used California phase 2 reformulated gasoline. Vehicle count, speed and other parameters relevant to carbonyl emissions were nearly the same from one assessment to the next. At the Tuscarora Mountain Tunnel, the fleet included LD vehicles and heavy-duty (HD) diesel trucks. This part of the study was designed to capture differences in percentage of LD and HD vehicles from one assessment to the next. Air downstream of KI oxidant scrubbers was sampled on silica gel cartridges coated with 2,4-dinitrophenylhydrazine (DNPH). Carbonyls were identified as their DNPH derivatives by liquid chromatography (LC) with detection by diode-array, UV-visible spectroscopy and by atmospheric pressure negative-ion chemical ionization mass spectrometry (MS). About 100 carbonyls were identified. For about 30 of these carbonyls, concentrations were measured at the inlet and outlet of both tunnels. This information was used to calculate on-road carbonyl emission factors for LD vehicles (Caldecott Tunnel) and for the overall fleet (Tuscarora Mountain Tunnel). At the Tuscarora Mountain Tunnel, data for the fleet were used to calculate carbonyl emission factors for LD vehicles and for HD diesel trucks, the majority of which were weight class 7-8 trucks. Carbonyl emission factors at the Caldecott Tunnel were calculated as milligrams of emissions per liter of fuel consumed. Those at the Tuscarora Mountain Tunnel were calculated as milligrams of emissions per distance traveled and then converted to milligrams per liter using the fuel economy reported by Gertler et al (2000) for this tunnel (14.75 km/L for LD vehicles and 3.15 km/L for HD vehicles). At the Caldecott Tunnel, the LD vehicles emission factor was 68.4 mg/L for total measured carbonyls; the ten most abundant carbonyls were, in decreasing order, formaldehyde, acetaldehyde, benzaldehyde, acetone, m-tolualdehyde, p-tolualdehyde, methacrolein, o-tolualdehyde, 2,5-dimethylbenzaldehyde, and crotonaldehyde. At the Tuscarora Mountain Tunnel, the LD emission factor was 94.9 mg/L for total measured carbonyls; the ten most abundant carbonyls were formaldehyde, acetone, acetaldehyde, heptanal, crotonaldehyde, 2-butanone, propanal, acrolein, methacrolein, and benzaldehyde. The weight class HD 7-8 vehicle emission factor at the Tuscarora Mountain Tunnel was 82.1 mg/L for total measured carbonyls; the ten most abundant carbonyls were formaldehyde, acetaldehyde, acetone, crotonaldehyde, m-tolualdehyde, 2-pentanone, a C5 saturated aliphatic carbonyl, 2-butanone, benzaldehyde, and methacrolein. The most abundant carbonyl was formaldehyde, which accounted for 45.4% (Caldecott, LD vehicles), 40.1% (Tuscarora Mountain, LD vehicles), and 25.8% (Tuscarora Mountain, HD vehicles) of total measured carbonyl emissions. The three most abundant carbonyls, formaldehyde, acetaldehyde, and acetone, together accounted for 63.0% (Caldecott, LD vehicles), 76.5% (Tuscarora Mountain, LD vehicles), and 50.5% (Tuscarora Mountain, HD vehicles) of total carbonyl emissions. At the Tuscarora Mountain Tunnel, HD vehicles emitted more unsaturated carbonyls, aromatic carbonyls, and dicarbonyls (as a percentage of total carbonyl emissions) than did LD vehicles. For LD vehicles, less acetone and more aromatic carbonyls (as a percentage of total carbonyl emissions) were emitted at the Caldecott Tunnel than at the Tuscarora Mountain Tunnel. The highway tunnel studies described in the main body of the report also offered an opportunity to examine the role of the sampling substrate, a critical aspect of the carbonyl sampling protocol. The results are described in Appendix A. Co-located samples, one collected using a DNPH-coated silica gel cartridge and the other using a DNPH-coated C18 cartridge, were collected downstream of KI oxidant scrubbers at the inlet and outlet of the Caldecott Tunnel. Statistical comparisons of the concentrations measured for about 30 carbonyls indicated good agreement between silica gel cartridges and C18 cartridges for about 25 carbonyls, including formaldehyde and acetaldehyde. Concentrations of acetone and 2-butanone measured using C18 cartridges were lower than those measured using silica gel cartridges.

Peroxyacetyl Nitrate in Atlanta, Georgia: Comparison and Analysis of Ambient Data for Suburban and Downtown Locations.

Peroxyacetyl nitrate (PAN) concentrations were measured at downtown and suburban locations in Atlanta, GA, in July and August 1992 as part of the SOS-SORP/ONA (Southern Oxidants Study-Southern Oxidants Research Program on Ozone Non-Attainment). PAN concentrations were generally higher at the downtown location than at the suburban location, but on days when the O3 concentration exceeded 80 ppbv, PAN concentrations were similar at both locations. On days when O3 did not exceed 80 ppbv, suburban PAN concentrations were much lower than downtown concentrations and resembled those reported for rural areas in the eastern United States. Regression analysis of PAN and O3 on NOx and total non-methane hydrocarbons (TNMHC) showed PAN to be most strongly dependent on morning NOx concentrations, while O3 was most dependent on morning TNMHC concentrations. NOx, PAN, and meteorological data from the suburban site were used in a one-dimensional transport model to estimate the accumulation rate of PAN to be ~1.5 x 106 molecules cm-3 sec-1. A simple kinetic model estimated peroxyacetyl radical concentrations to be ~0.5 pptv at the suburban location.