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1.
The relationship between inhalable endotoxin, inhalable dust and airborne bacteria was studied in a hen house. Neither the concentration of inhalable dust nor the concentration of airborne bacteria are suitable to reflect the concentration of airborne endotoxin. Furthermore it was found that the endotoxic activity can persist over a long period of time in dust samples. Therefore an accumulation of endotoxin in different environments is possible. Airborne endotoxin seems to be a suitable marker to characterize exposure to airborne organic dust, since this toxin is responsible for different respiratory diseases (e.g. toxic pneumonitis, airway obstructions) and the toxic activity of endotoxin in dust samples is known to persist for a long time. 相似文献
2.
Duan H Chai T Müller W Zucker BA 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(1-2):40-44
Concentration of airborne endotoxins, airborne aerobic bacteria and airborne aerobic gram-negative bacteria were measured in 3 rabbit houses. Further, the species composition of the airborne gram-negative bacterial flora was investigated. The total amount of airborne endotoxin ranged from 22 to 774 EU/m3 (Endotoxin Units/m3). The number of total airborne aerobic bacteria varied between 780 and 20100 CFU/m3, the number of airborne aerobic gram-negative bacteria between 39 and 1030 CFU/m3. Most gram-negative bacterial isolates belonged to the family Enterobacteriaceae with E. coli as primary species. In two rabbit houses also airborne Pasteurella multocida spp. multocida, the most common respiratory pathogen of rabbits, was isolated. 相似文献
3.
Airborne gram-negative bacterial flora in animal houses 总被引：1，自引：0，他引：1
Zucker BA Trojan S Müller W 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2000,47(1):37-46
The concentration and the species composition of airborne gram-negative bacteria were studied in four cattle houses, one pig house and one poultry barn. On average only between 0.02 and 5.2% of the total number of culturable aerobic bacteria were identified as gram-negative bacteria. Obligate anaerobic gram-negative bacteria were not isolated at all. In the airborne gram-negative bacterial flora the following bacterial families dominated: the Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae. Within the family of the Enterobacteriaceae the species Escherichia coli and Enterobacter agglomerans were predominant. In animal houses using straw as bedding material Ent. agglomerans was most frequent, whereas in animal houses without litter E. coli was mainly found. Airborne Neisseriaceae were isolated very frequently in cow barns with Acinetobacter lowffii as the primary species. Airborne Pseudomonadaceae were found in high concentrations during periods of high air humidity. The results presented may also give some indications on the origin and sources of airborne endotoxins in animal housing. 相似文献
4.
Confined animal production systems produce increased bioaerosol concentrations, which are a potential respiratory health risk to individuals on site and downwind. In this longitudinal study, airborne endotoxin and microorganisms were collected during the spring, summer, and fall at a large, open-freestall dairy in southern Idaho. Compared with the background ambient atmosphere, both endotoxin and culturable heterotrophic bacteria concentrations were up to several-hundred-fold greater 50 m downwind from the facility, then decreased to near background concentrations at 200 m. However, downwind fungi concentrations were not increased above background concentrations. At 50 m downwind, the average inhalable endotoxin concentration ranged from 5 to 4,243 endotoxin units per m?3, whereas bacteria concentrations ranged from 102 to 10? cfu per m?3 of air. Although the bioaerosol concentrations did not follow a seasonal trend, they did significantly correlate with meteorological factors. Increasing temperature was found to be positively correlated with increasing bacteria (r = 0.15, P < 0.05), fungi (r = 0.14, P < 0.05), and inhalable endotoxin (r = 0.32, P < 0.001) concentrations, whereas an inverse relationship occurred between the concentration and solar radiation. The airborne concentrations at 50 m were also found to be greatest at night, which can likely be attributed to changes in animal activity and wind speed and reduced exposure of the airborne microorganisms to UV radiation. 相似文献
5.
Zucker BA Bonin H Müller W 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(5-6):224-228
In the study presented here the relationship between the hygienic condition and the concentration of different air contaminants in two pig fattening houses was investigated. Deficiencies in routine cleaning, which were characterized by an increased soiling of animals and stable surfaces with faeces, led to increased concentrations of airborne dust, airborne endotoxins as well as increased numbers of total airborne bacteria and airborne gram-negative bacteria. However these deficiencies were not reflected by the concentration of airborne Clostridium perfringens which were earlier postulated as an indicator of faecal pollution in the air of cattle barns. Furthermore the results of this study were used to discuss advantages and disadvantages of impingement and impaction for the sampling of airborne microorganisms in animal houses. 相似文献
6.
Salmonella in birds is a concern because of the human foodborne illness associated with the consumption of poultry meat and eggs. One of the methods of transmission of Salmonella within a flock can be by the air. Therefore, we used reduction of transmission of Salmonella to monitor the effectiveness of the electrostatic space charge system (ESCS). During the average broiler breeder laying cycle of 40 wk, a large amount of dust becomes airborne and accumulates on walls, ceiling, and equipment. Many microorganisms adhere to these dust particles, making dust an excellent vector for horizontal disease transmission between birds.We used two environmentally controlled rooms containing commercial broiler breeders to evaluate the effectiveness of an ESCS that produced a strong negative electrostatic charge to reduce airborne dust and, subsequently, microorganism levels. The ESCS caused the dust to become negatively charged, therefore moving to the grounded floor in the treatment room. The use of the ESCS resulted in a significant reduction (P < 0.0001, 61% reduction) in airborne dust concentration levels, which resulted in a significant reduction (P < 0.0001, 76% reduction) in total airborne bacteria and gram-negative bacteria (48% reduction) in the treatment room. Significant reductions (P < 0.05) of gram-negative bacteria (63% reduction) on the egg collection belts were also recorded in the treatment room, which resulted in a significant reduction (P < 0.0001) of gram-negative bacteria (28% reduction) on the eggshell surface. The ESCS treatment resulted in fewer Salmonella enteritidis-positive hens and their progeny from the treatment room due to reductions of dust and airborne bacteria. In addition, this significant reduction in bacteria on the eggshell surface should result in less bacteria in the day-old chicks, therefore better early chick livability. There was no significant difference (P > 0.05) in egg production, male or female body weights, mortality, or reproductive performance in the ESCS room compared with the control room. 相似文献
7.
The concentration and the species composition of airborne gram‐negative bacteria were studied in four cattle houses, one pig house and one poultry barn. On average only between 0.02 and 5.2 % of the total number of culturable aerobic bacteria were identified as gram‐negative bacteria. Obligate anaerobic gram‐negative bacteria were not isolated at all. In the airborne gram‐negative bacterial flora the following bacterial families dominated: the Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae. Within the family of the Enterobacteriaceae the species Escherichia coli and Enterobacter agglomerans were predominant. In animal houses using straw as bedding material Ent. agglomerans was most frequent, whereas in animal houses without litter E. coli was mainly found. Airborne Neisseriaceae were isolated very frequently in cow barns with Acinetobacter lowffii as the primary species. Airborne Pseudomonadaceae were found in high concentrations during periods of high air humidity. The results presented may also give some indications on the origin and sources of airborne endotoxins in animal housing. 相似文献
8.
High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing. 相似文献
9.
B Urbain J Mast D Beerens T Q N'Guyen B Goddeeris M Ansay P Gustin 《American journal of veterinary research》1999,60(9):1055-1060
OBJECTIVE: To assess the effects of inhalation of feed flour dust and dustborne endotoxin on respiratory tracts of pigs. ANIMALS: 29 healthy Belgian Landrace pigs. PROCEDURE: Pigs housed in an environmental chamber were exposed for 6 days to feed flour dust (1 to 15 mg/m3) and dustborne endotoxins (50 to 2,500 ng/m3). Effects were evaluated by measuring albumin concentration, lactate dehydrogenase (LDH) activity, cell composition of nasal lavage (NL) and bronchoalveolar lavage (BAL) fluids and blood, and percentages of CD4+ and CD8+ T lymphocytes in blood and lavage fluids. Dustborne endotoxin was obtained by mixing endotoxins from Escherichia coli (serotype O127:B8) with feed flour before spraying the flour in the environmental chamber. RESULTS: Exposure did not affect cell composition of NL fluid or blood. Total cell counts of BAL fluids were increased in all groups exposed to dust. Macrophage counts were increased in pigs exposed to inhalable dust concentrations as low as 4.4 mg/m3, and lymphocyte counts were increased in groups exposed to high dust concentrations. Percentages of CD4+ and CD8+ T lymphocytes in blood and lavage fluids were unchanged. In all dust-exposed groups, albumin content of BAL fluid was increased, whereas LDH activity was unaffected. Macrophage and lymphocyte infiltration and edema in the bronchi were identified by light microscopy. Effects attributable to E. coli endotoxin exposure were not identified. CONCLUSIONS: Inhalation of feed flour dust did not affect nasal mucosa but did induce bronchial airway inflammation. Dustborne endotoxins did not have effects attributable to endotoxin alone. 相似文献
10.
According to the present study the limulus amebocyte lysate test (LAL) seems to be a convenient test to detect endotoxin in milk from udder quarters with and without inflammation. The correlation between endotoxin concentration and the results from the bacteriological investigation of 79 milk samples was good (Table I). Determination of endotoxin in 20 milk samples from cases of acute clinical mastitis with high cell count and a negative bacteriological culture showed that all but one had an endotoxin concentration of greater than 1.0 ng/ml milk (Table II). By using a micromethod of the LAL it is possible to detect cases of mastitis caused by gram-negative bacteria about one hour after the sample has reached the laboratory. In a preliminary field study milk from 13 cases of acute clinical mastitis were tested by a modified limulus amebocyte lysate (LAL) test ("cowshed test"). A 100% correlation to bacteriological findings was observed (Table IV). By using the LAL test to detect mastitis cases caused by gram-negative bacteria great economic advantages and less risk for resistance problems can be achieved by using proper antibiotics. This is the fact in Sweden where the frequency of acute clinical mastitis caused by streptococci (100% of strains sensitive for penicillin) and Staphylococcus aureus (about 90% of strains sensitive for penicillin) is high (70-80%) and about 20% are caused by gram-negative bacteria, mostly E. coli. 相似文献
11.
The aim of the study was to evaluate the effects of microbial aerosols on ducks’ welfare and provide information on which to establish microbial aerosol concentration standards for poultry.
A total of 1800 1-d-old Cherry Valley ducks were randomly divided into 5 groups (A, B, C, D and E) with 360 ducks in each. To obtain objective data, each group had three replications. Different microbial aerosol concentrations in different groups were created by controlling ventilation and bedding cleaning frequency. Group A was the control group and hygienic conditions deteriorated progressively from group B to E.
A 6-stage Andersen impactor was used to detect the aerosol concentration of aerobes, fungi, gram-negative bacteria and an AGI-30 microbial air sampler detected endotoxins. Physiological stress was evaluated in the ducks by adrenocorticotropic hormone (ACTH) values in serum.
To assess the effects of bioaerosol factors, welfare indicators including fluctuating asymmetry (FA), appearance and gait as well as the Lactobacillus caecal concentration were evaluated.
The data showed group D had already reached the highest limit of concentration of airborne aerobic bacteria, airborne fungi, airborne gram-negative bacteria and airborne endotoxin. The ducks in this group had significantly increased serum ACTH values and significantly decreased caecal lactobacilli concentration. Furthermore, appearance and gait scores, wing length and overall FA and caecal Lactobacillus concentration in this group were significantly increased at 6 and 8 weeks of age.
In conclusion, high concentrations of microbial aerosol adversely affected the welfare of meat ducks. The microbial aerosol values in group D suggest a preliminary upper limit concentration of bioaerosols in ambient air for healthy meat ducks.
12.
Huneau-Salaün A Le Bouquin S Bex-Capelle V Huonnic D Balaine L Guillam MT Squizani F Segala C Michel V 《British poultry science》2011,52(5):523-530
1. Endotoxins as components of organic dust may have adverse effects on the respiratory health of workers in poultry buildings. The move towards more welfare-friendly housing systems for layers may increase worker exposure to air contaminants due to the use of litter.
2. The endotoxin concentrations in the inhalable fraction of airborne dust (below 100?µm) from cage and alternative system houses (on-floor, free range and aviaries) were compared under both experimental and commercial conditions.
3. The endotoxin concentration was higher in experimental aviaries (median: 565?EU/m3, range: 362-1491?EU/m3) than in cage housing (98?EU/m3 (51-470)).
4. In field conditions, the endotoxin concentration in the air of 13 alternative houses was higher (35 to 3156?EU/m3) than in cage system buildings (n?=?8, 78-576?EU/m3). It was correlated to the respirable dust concentration (fraction below 5?µm) and to the temperature inside the hen house but no seasonal variation was observed.
5. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems. 相似文献
13.
Commercial hatcheries typically infuse hydrogen peroxide or formaldehyde gas into hatching cabinets to reduce airborne pathogens that may lead to disease transmission during the hatch. A nonchemical option, an electrostatic space charge system (ESCS), was customized for full-sized commercial hatching cabinets and was tested extensively in broiler hatcheries. The ESCS cleans air by transferring a strong negative electrostatic charge to dust and microorganisms that are aerosolized during the hatch and collecting the charged particles on grounded plates or surfaces. In studies with three poultry companies, the ESCS resulted in significant (P < 0.0001) reductions of airborne dust of 77%-79%, in Enterobacteriaceae and fungus levels not significantly different (P > or = 0.05) from those with formaldehyde, and in 93%-96% lower Enterobacteriaceae than with no treatment or with hydrogen peroxide treatment (P < 0.01). The ESCS significantly (P < 0.05) reduced airborne Salmonella by 33%-83% compared with no treatment or hydrogen peroxide treatment. Results of this study suggest that the ESCS is a viable alternative to chemical treatment for reducing airborne pathogens in full-sized commercial hatchers, and it also provides dust control and containment, which should be helpful in reducing cross contamination and loading of ventilation ducts within different areas of the hatchery. 相似文献
14.
Blood culture of the canine patient 总被引：2，自引：0，他引：2
D C Hirsh S S Jang E L Biberstein 《Journal of the American Veterinary Medical Association》1984,184(2):175-178
Blood for bacteriologic culture was obtained from 581 sick dogs. Of these, 134 (23%) were considered to have bacteremia. The conditions most frequently associated with bacteremia were malignant neoplasms and infections of the skeletal, cardiovascular, and urogenital systems. The most frequently isolated bacteria were members of the family Enterobacteriaceae and coagulase-positive staphylococci, in sum accounting for more than 50% of the 150 isolates. Most of the dogs with bacteremia had high proportions of immature neutrophils, segmented neutrophils, and monocytes in blood. Dogs with bacteremia and osteomyelitis due to staphylococci had normal hemograms. Blood from dogs with bacteremia due to gram-negative bacteria was more likely to have a high proportion of immature and segmented neutrophil leukocytes than was blood from dogs with bacteremia due to a gram-positive species. Toxic neutrophils were observed more often in blood obtained from patients with bacteremia due to gram-negative bacteria. The development of fever correlated with the bacteremic state regardless of the species of bacteria in the blood. 相似文献
15.
16.
232 isolates of gram-negative, oxidase-negative bacteria, isolated from various samples of different animal species, were tested with help of RAPIDEC coli for the production of beta-glucuronidase, beta-galactosidase and indole. The test correctly identified 164 of 175 E. coli strains (sensitivity 93.7%) and correctly indicated that 57 of 57 isolates of the family Enterobacteriaceae (7 Citrobacter sp., 18 Enterobacter sp., 16 Klebsiella sp., 10 Proteus sp., 2 Providencia sp. and 4 Salmonella sp.) were not E. coli (specificity 100%). 相似文献
17.
Purdy CW Straus DC Parker DB Wilson SC Clark RN 《American journal of veterinary research》2004,65(1):45-52
OBJECTIVES: To determine the bacterial, fungal, and endotoxin concentrations in aerosolized ambient air during the winter and summer in feedyards located in the Southern High Plains, identify aerosolized microbial pathogens, and determine the size of microbial and dust components. SAMPLE POPULATION: Aerosol samples were obtained from 7 feedyards. PROCEDURE: Aerosol samples were collected upwind, on-site, and downwind from each feedyard at a point 1 m above the ground by use of biological 2- and 6-stage cascade impactors. RESULTS: Significantly more microbes were cultured from on-site and downwind samples than upwind samples. There were significantly more microbes during the summer than during the winter. However, mean endotoxin concentration was significantly higher during the winter (8.37 ng/m3) than the summer (2.63 ng/m3). Among 7 feedyards, mean +/- SE number of mesophilic bacteria (1,441 +/- 195 colony-forming units [CFUs]/m3) was significantly higher than mean number of anaerobic bacteria (751 +/- 133 CFUs/m3) or thermophilic bacteria (54 +/- 10 CFUs/m3) in feedyard air. Feedyard aerosol samples contained more mesophilic fungi (78 +/- 7 CFUs/m3) than thermophilic fungi (2 +/- 0.2 CFUs/m3). Eighteen genera of bacteria were identified by use of an automated identification system. CONCLUSIONS AND CLINICAL RELEVANCE: It appeared that gram-negative enteric pathogens offered little risk to remote calves or humans via ambient aerosols and that gram-positive pathogens of the Bacillus, Corynebacterium, and Staphylococcus spp can be spread by aerosols in and around feedyards. It was common to detect concentrations of endotoxin in the ambient air of 7 feedyards. 相似文献
18.
Whyte RT 《British poultry science》2002,43(3):364-373
1. The occupational exposure to inhalable dust and ammonia of 12 stockmen working in barn systems conforming to the UK Royal Society for the Prevention of Cruelty to Animals (RSPCA) Freedom Foods requirements was measured and compared with established limits for occupational exposure. The influence of the type of task upon the daily exposure was assessed and comparisons of daily exposure were made with that of battery cage system stockmen. 2. The mean inhalable dust exposures experienced by poultry stockmen working in barn systems was 10.8 mg/m3 (9.5 mg/m3, time-weighted average), for a complete working day. This was greater (P < 0.01) than the mean dust exposure measured in current cage systems of 4.8 mg/m3 (4.4 mg/m3, time-weighted average). The individual values of dust exposure for 4 of the 12 barn stockmen exceeded the occupational exposure standard (OES) of 10.0 mg/m3 for inhalable dust, whereas that of all of the individual cage stockmen taking part in this study did not. 3. The mean ammonia exposure experienced by poultry stockmen working in barn systems was 14 ppm (11 ppm, time-weighted average), for a complete working day. This also was greater (P < 0.01) than the mean ammonia exposure measured in current cage systems of 8 ppm (7 ppm, time-weighted average). None of the individual values of ammonia exposures for both barn and cage system stockmen taking part in this study exceeded the OESs of 25 ppm, although the short-term limit of 35 ppm for 15 min was exceeded on a number of occasions. 4. Current methods for assessing the combined effects of dust and ammonia indicated that 8 of the 12 barn stockmen were at risk compared with 1 of the 8 cage system stockmen. 5. The average dust burden in daily common tasks such as maintenance and collecting floor eggs ranged from 5 to 15 mg/m3, while intermittent common tasks such as nest box checks and litter spreading ranged from 13 to 35 mg/m3. Tasks that had the highest exposure values included sweeping and partition removal, ranging from 63.3 to 70.7 mg/m3. 6. Designs of the typical barn systems investigated offer little scope for reducing airborne dust for common daily tasks. Personal respiratory protection while carrying out tasks that result in high dust concentrations in barns is advisable. 相似文献
19.
Schulz J Runge M Schröder C Ganter M Hartung J 《DTW. Deutsche tier?rztliche Wochenschrift》2005,112(12):470-472
Local epidemics of Q fever occur sporadically in Germany, mainly in rural residential communities. There is increasing evidence that these outbreaks, which are caused by Coxiella burnetii, are related particularly to the lambing season and shearing periods of nearby sheep holdings. It is assumed that this zoonotic agent is massively emitted from the placenta of infected ewes at birth and during shearing of wool contaminated with infected faeces of ticks. However, little is known about the airborne transmission and travel distance of this infectious agent, and only few attempts have been made to isolate it directly from the air. This paper describes for the first time the isolation and detection of C. burnetii in the air of an enclosed sheep barn during shearing of a herd which had tested positive for C. burnetii serologically and by PCR. Samples of inhalable dust samples were taken using I.O.M. samplers with glass fibre and polycarbonate filters at a flow rate of 2.5 l/min. The sampling time was nearly 4.5 h. Two sampling positions were set up on both sides of the shearing place at a distance of 3 m and 1.5 m above the ground. A third position with the same sampling equipment was not activated and served as a sampling and transport control. In the laboratory, the glass fibre filters were used to determine the dust concentration. The polycarbonate filters were treated in a specific breakdown procedure which inactivates PCR inhibitors, followed by amplification and sequencing of a specific DNA section of C. burnetii, which was found in the dust from both active sampling positions. The investigation clearly shows that the sampling and detection methods used in this small field study are suitable for the detection of C. burnetii in the air of sheep barns. The results confirm experimentally the high risk of airborne transmission of C. burnetii from sero-positive sheep herds during shearing. However, little is known about the effective travel distance of infective airborne C. burnetii particles. There is an urgent need for more detailed investigations on the emission and airborne dispersion of infectious C. burnetii particles in order to improve our understanding of the health risks caused by this zoonotic agent originating from sheep herds. 相似文献
20.
Biofilters and bioscrubbers are ultimate tools to control odour emissions from animal houses in pig and poultry production. Little is known about the efficiency of these devices to remove airborne particulate pollutants such as dust, microorganisms and endotoxins from the exhaust air of animal houses. Preliminary results of a one year field campaign in two piggeries show that the biofilter reduces the number of particles in the exhaust air by 79 to 96%. The efficiency of the bioscrubber was 22% only. The biofilter reduced the amount of mesophilic bacteria by 11% and 71%, respectively, the amount of thermotolerant fungi by 71%. The concentration of endotoxin and mesophilic fungi in the clean air after the bioscrubber was 3.8 times resp. 2.7 times higher than in the air of the piggery. The washing water which is regularly recirculated in both systems was highly contaminated with varying amounts of air contaminants. It seems that the quality of the washing water distinctly influences the reduction efficiency of both systems. 相似文献