Year-long assessment of airborne endotoxin at a concentrated dairy operation

In this study, we monitored total airborne endotoxins at upwind and downwind sites at a large open-lot dairy each month for a year. At the upwind site, the average airborne concentration was 28.5 endotoxin units (EU) m⁻³, while at the downwind edge of the lot and 200 m from the lot edge, the average concentrations were 169 and 72 EU m⁻³, respectively. At the downwind edge of the lot, there was a significant correlation between the airborne endotoxin concentration and wind speed or air temperature. A comparison between total and inhalable airborne endotoxin concentrations, near the end of the study, revealed no significant differences between the two endotoxin collection methods. Our data suggest that endotoxin exposure can be reduced as one increases their distance from the open-lot dairy.     

Assessment of welfare indicators in dairy farms offering pasture at differing levels

In terms of animal welfare, farming systems of dairy cows are perceived positively by consumers when compared to pigs or poultry. A main reason is that the majority of consumers associate dairy farming with pasture, which in turn they relate with benefits for animal health and welfare. However, holistic scientific assessments of the effects of pasturing on animal welfare are rare. Hence, it was the aim to study the animal welfare level in 61 German loose housing dairy farms by using the measures of the Welfare Quality® protocol for dairy cattle (WQP). Data were collected twice per farm at the end of the pasture season (July to October) and approximately 6 months later at the end of the barn season (December to April). Farms were classified based on the duration cows had access to pasture per day during the pasture season: group 1 (G1)>10 h; group 2 (G2) 6 to 10 h; group 3 (G3)<6 h and group 4 (G4) without pasture access. The average herd size was 129 Holstein-Friesian or Red-Holstein cows (range 58 to 527). In addition to WQP data, performance data were gathered from routine herd data recordings. The indicators were aggregated to criteria applying the scoring system of the WQP. G4 received lower scores at the first than at the second visit for the criterion absence of hunger, while there were no differences between visits in the other groups (P=0.58 – group×farm visit effect). All pasturing groups were scored better at the end of the pasture season than G4 for the criterion comfort around resting (P<0.01). Compared with G1 for both farm visits and G2 for the end of the barn season, G4 reached inferior scores for the criterion absence of injuries, including indicators such as hairless patches, lesions, and swellings and lameness. At both assessments G2 was scored higher than the other groups for the criterion absence of diseases (P=0.04). In conclusion, pasture access had positive effects only on selected welfare indicators, however, these effects were not maintained throughout the barn season.     

Characterization of bioaerosols from dairy barns: reconstructing the puzzle of occupational respiratory diseases by using molecular approaches

To understand the etiology of exposure-related diseases and to establish standards for reducing the risks associated with working in contaminated environments, the exact nature of the bioaerosol components must be defined. Molecular biology tools were used to evaluate airborne bacterial and, for the first time, archaeal content of dairy barns. Three air samplers were tested in each of the 13 barns sampled. Up to 10(6) archaeal and 10(8) bacterial 16S rRNA genes per m(3) of air were detected. Archaeal methanogens, mainly Methanobrevibacter species, were represented. Saccharopolyspora rectivirgula, the causative agent of farmer's lung, was quantified to up to 10(7) 16S rRNA genes per m(3) of air. In addition, a wide variety of bacterial agents were present in our air samples within the high airborne bioaerosol concentration range. Despite recommendations regarding hay preservation and baling conditions, farmers still develop an S. rectivirgula-specific humoral immune response, suggesting intense and continuous exposure. Our results demonstrate the complexity of bioaerosol components in dairy barns which could play a role in occupational respiratory diseases.     

Assessment of a new utero-tubal junction insemination device in dairy cattle

A new artificial insemination device for semen deposition near the utero-tubal junction in cattle (Ghent device) has been developed at the Ghent University (Belgium). In this study, the effect of the new insemination device on sperm quality was evaluated. Moreover, in a field trial 4064 dairy cows were inseminated by 12 inseminators to examine the efficacy of the device under field conditions.The Ghent device is a disposable plastic catheter which can easily follow the curvature of the uterine horns and thus reach the utero-tubal junction (UTJ). After expulsion of the inseminate with 0.7 or 1.7 ml of air, 19.0% of the insemination dose remained in the insemination catheter. Sperm loss can be diminished to 9.0% of the original insemination dose when the insemination catheter is flushed with 0.1 ml of air, followed by 0.6 ml of physiological saline solution. No toxic effect of the insemination catheter on sperm quality or fertilizing capacity was found. In the field trial, sperm were inseminated in dairy cattle which were divided in three groups. The first group was inseminated in the uterine body with the conventional insemination device, the second group in the uterine body with the Ghent device, and the third group in the tip of both uterine horns with the Ghent device. Each insemination was performed with 10 x 10(6) to 15 x 10(6) frozen-thawed spermatozoa. The pregnancy rates (PRs) were significantly affected by the insemination technique (P = 0.02), by the inseminator (P = 0.01), by heifer or cow (P < 0.01), and by the insemination number (P < 0.01). Pregnancy rates obtained with the conventional insemination device (57.6%) were significantly better than those obtained with the Ghent device in the uterine body (52.7%) (P < 0.01), but did not differ significantly from those obtained after deep insemination into both uterine horns (53.8%) (P = 0.27). It can be concluded that the Ghent device is suitable for utero-tubal junction insemination of dairy cattle under field conditions. Whether the Ghent device is also suitable for insemination with lower insemination doses is at present under investigation.     

Unusual pathogenic bacterium isolated from microbial communities of bioaerosols at Chilean Patagonian lakes

Bioaerosols are transported from warm regions and lower latitudes of the planet to colder regions and higher latitudes, such as the Chilean Patagonia. The role of bioaerosols deposition in remote lake ecosystems is a potentially important process, but it has not yet been fully studied. The aim of this study was to detect and characterize potentially pathogenic viable microorganisms in bioaerosols in a pristine area. Samples were collected from the air, at three remote lakes in the Chilean Patagonia, using a sterile filtration system equipped with 0.2-μm-pore-size nitrocellulose filters. The bacterial community present in bioaerosols was studied using scanning electron microscopy (SEM) and denaturing gradient gel electrophoresis. Isolates were identified and characterized for phenotypic and 16S rDNA analysis and antibiotic resistance. SEM observations of samples from each lake showed the presence of bacteria with different morphologies, and after culturing, the identification results revealed that they were strains of Acinetobacter, Alcaligenes, Edwarsiella, Pseudomonas, Burklolderia, Moraxella, Sphingomonas and CDC NO-1. CDC NO-1, uncommonly isolated worldwide, stands out from the rest of the isolates because it is a rarely found bacterium so far associated with dog and cat bites and was found at two out of three pristine lakes studied (Alto and Verde). This work demonstrates, for the first time, the presence of CDC NO-1, a clinically important Gram-negative microorganism, in bioaerosols and first report of CDC-NO1 isolation in Chile. Besides its presence in remote lakes, its antibiotic resistance is worth mentioning.     

Polymerase chain reaction analysis of laboratory generated bioaerosols

The common methods for analyzing bioaerosols are based on maintaining organism viability and quantifying culturability which may result in the underestimation of microbial concentrations. The present study employed a well-developed technique that only requires cellular DNA to identify organisms. Polymerase chain reaction (PCR) was chosen to amplify specific DNA sequence from an organism, to detect and semi-quantify organisms. Suspensions ofFrancisella tularensis were aerosolized in a chamber, and air samples were collected using impingers. Samples were analyzed using limiting dilution PCR, and the results compared with those from a traditional plate counting. Results indicated that the limiting dilution PCR provides a new way to identify and quantify bioaerosols that does not rely on viability and culturability. Therefore, the method would provide a more reliable estimate of airborne bacterial concentrations compared to traditional plate counts.     

Size distributions of total airborne particles and bioaerosols in a municipal composting facility

Size distributions of total airborne particles and bioaerosols were measured in a full-scale composting facility, using an optical particle counter and an agar-inserted six-stage impactor, respectively. Higher concentrations of total airborne particles and bioaerosols were detected at a sampling location near the screening process preceded by the composting process than at sampling locations in the composting process. At the sampling location near the screening process, the concentrations of total airborne particles were approximately 10(8)particles/m3 at the size of 0.3 microm and 10(5)particles/m3 at 6.2 microm. The concentration of bioaerosols was about 10(4)CFU/m3 in each stage of 7.0 microm (1st stage), 7.0-4.7 microm (2nd), 4.7-3.3 microm (3rd), 3.3-2.1 microm (4th), 2.1-1.1 microm (5th) and 1.1-0.65 microm (6th). Most of submicron particles smaller than 1 microm among the total airborne particles were believed to originate from the ambient air.     

卫生填埋场微生物气溶胶的逸散及潜在风险

随着对微生物气溶胶认识的提高,其产生、来源、扩散及风险研究获得了越来越多的关注。卫生填埋场是微生物气溶胶的重要产生源之一。本文阐述了卫生填埋场气溶胶颗粒中微生物的浓度水平、粒径分布、种群结构,解析了微生物气溶胶的逸散特征及影响因素,介绍了微生物气溶胶对人体健康的潜在风险及评价方法,并展望了未来卫生填埋场逸散微生物的研究趋势及方向,为卫生填埋场微生物气溶胶的控制与削减提供了科学依据和参考。     

Immunogenic properties of archaeal species found in bioaerosols

The etiology of bioaerosol-related pulmonary diseases remains poorly understood. Recently, archaea emerged as prominent airborne components of agricultural environments, but the consequences of airway exposure to archaea remain unknown. Since subcomponents of archaea can be immunogenic, we used a murine model to study the pulmonary immune responses to two archaeal species found in agricultural facilities: Methanobrevibacter smithii (MBS) and Methanosphaera stadtmanae (MSS). Mice were administered intranasally with 6.25, 25 or 100 μg of MBS or MSS, once daily, 3 days a week, for 3 weeks. MSS induced more severe histopathological alterations than MBS with perivascular accumulation of granulocytes, pronounced thickening of the alveolar septa, alveolar macrophages accumulation and increased perivascular mononucleated cell accumulation. Analyses of bronchoalveolar lavage fluids revealed up to 3 times greater leukocyte accumulation with MSS compared to MBS. Instillation of 100 μg of MBS or MSS caused predominant accumulation of monocyte/macrophages (4.5×10(5) and 4.8×10(5) cells/ml respectively) followed by CD4(+) T cells (1.38×10(5) and 1.94×10(5) cells/ml respectively), B cells (0.73×10(5) and 1.28×10(5) cells/ml respectively), and CD8(+) T cells (0.20×10(5) and 0.31×10(5) cells/ml respectively) in the airways. Both archaeal species induced similar titers of antigen-specific IgGs in plasma. MSS but not MBS caused an accumulation of eosinophils and neutrophils in the lungs, which surprisingly, correlated inversely with the size of the inoculum. Stronger immunogenicity of MSS was confirmed by a 3 fold higher accumulation of myeloid dendritic cells in the airways, compared to MBS. Thus, the dose and species of archaea determine the magnitude and nature of the pulmonary immune response. This is the first report of an immunomodulatory role of archaeal species found in bioaerosols.     

微生物气溶胶采集技术的特点及应用

微生物气溶胶是悬浮于空气中粒径差异显著的生物粒子。污水处理、垃圾填埋等污水和固体废弃物的处理过程会产生大量的微生物气溶胶。近年来,随着对微生物气溶胶的不断认识,对其产生、逸散以及危害环境和人体的研究越来越多。在过去的150年,研究者们研发了多种微生物气溶胶采集技术和仪器设备,每种采集技术各有特点和适用条件。本文阐述沉降法、惯性采样法和过滤法3种典型微生物气溶胶采集技术的特点和原理,分析各种采样设备的适用性,为微生物气溶胶的采集和研究提供参考。     

Loss of blood at operation; a method for continuous measurement

A method for continuous measurement of surgical blood loss has been devised and has been used clinically in some 400 cases. The method combines volumetric measure of the suction loss and gravimetric measure of the sponge loss. The volumetric device automatically deducts the volume of rinse water used and thus measures the amount of blood collected in a metering cylinder. The suction loss scale shows continuously the amount of blood in the metering cylinder. The gravimetric device requires counting sponges into the weighing pan, and turning a dial scale to deduct the initial weight of the sponges. The volume of blood in the sponges is then read directly on the dial scale. Use of the instrument, which is under the supervision of the anesthesiologist, adds about two minutes per hour to the time normally required for counting the sponges; and about three minutes per hour is required for tending the volumetric instrument.In clinical use, knowing constantly the amount of blood loss permits the starting of transfusion before serious deficit develops, and then maintaining the patient's blood volume at a predetermined optimum level. In some 400 cases the continuous measurement of the blood loss served as a reliable guide for carrying out the loss-replacement plan within close limits of accuracy.     

Early cement damage around a femoral stem is concentrated at the cement/bone interface

This study aimed to improve understanding of the mechanical aspects of cemented implant loosening. After aggressive fatigue loading of stem/cement/femur constructs, micro-cracks and stem/bone micro-motions were quantified to answer three research questions: Are cracks preferentially associated with the stem/cement interface, the cement/bone interface or voids? Is cement damage dependent on axial position? Does cement damage correlate with micro-motion between the stem and the bone? Eight Charnley Cobra stems were implanted in cadaveric femora. Six stem/cement/femur constructs were subjected to "stair-climbing" loads for 300 kcycles at 2Hz. Loads were normalized by construct stiffness to avoid fracture. Two additional constructs were not loaded. Transverse sections were cut at 10mm intervals, stained with a fluorescent dye penetrant and examined using epi-fluorescence stereomicroscopy. Crack lengths and cement areas were recorded for 9 sections per specimen. Crack length-density was calculated by dividing summed crack length by cement mantle area. To isolate the effect of loading, length-density data were offset by the baseline length-density measured in the non-loaded specimens. Significantly more cracks were associated with the interdigitated area (35.1%+/-11.6%) and the cement/bone interface (31.0%+/-6.2%) than with the stem/cement interface (11.0%+/-5.2%) or voids (6.1%+/-4.8%) (p<0.05). Load-induced micro-crack length-density was significantly dependent on axial position, increasing proximally (p<0.001). Micro-motions were small, all stems rotated internally. Cement damage did not correlate with micro-motion.     

Generation of bioaerosols during manual mail unpacking and sorting

AIMS: The dynamics of bioaerosol generation in specific occupational environments where mail is manually unpacked and sorted was investigated. METHODS AND RESULTS: Total number of airborne particles was determined in four different size classes (0.3-0.5, 0.5-1, 1-5 and >5 microm) by laser particle counting. Time dependent formation of bioaerosols was monitored by culturing methods and by specific staining followed by flow cytometry. Besides handling of regular mail, specially prepared letters ('spiked letters') were added to the mailbags to deliberately release powdered materials from letters and to simulate high impact loads. These letters contained various dry powdered biological and nonbiological materials such as milk powder, mushrooms, herbs and cat litter. Regarding the four size classes, particulate aerosol composition before mail handling was determined as 83.2 +/- 1.0, 15.2 +/- 0.7, 1.7 +/- 0.4 and 0.04 +/- 0.02%, respectively, whereas the composition changed during sorting to 66.8 +/- 7.9, 22.3 +/- 3.6, 10.4 +/- 4.0 and 0.57 +/- 0.27%, respectively. Mail processing resulted in an increase in culturable airborne bacteria and fungi. Maximum concentrations of bacteria reached 450 CFU m(-3), whereas 270 CFU of fungi were detected. CONCLUSIONS: Indoor particle concentrations steadily increased during mail handling mostly associated with particles of diameters >1 microm. However, it was not possible to distinguish spiked letters from nonspiked by simple particle counting and CFU determinations. SIGNIFICANCE AND IMPACT OF STUDY: The dynamics of bioaerosol generation have to be addressed when monitoring specific occupational environments (such as mail sorting facilities) regarding the occurrence of biological particles.     

Immunogenicity of a chromatographically concentrated influenza vaccine

The immunogenicity of the Czechoslovak-made commercial vaccine Adinvira as well as that of the chromatographically concentrated vaccine Leningrad of Soviet origin was evaluated in an immunization project. The both vaccines were well tolerated after administration, the Soviet-made Leningrad brand featuring greater efficiency in eliciting an antibody response against influenza virus haemagglutinin.     

Microbial composition of bioaerosols in indoor wastewater treatment plants

Aerobiologia - Wastewater treatment is one of the major biotechnological processes used to treat municipal and industrial sewage. All the steps involved in the removal of contaminants from...     

Linking the conventional and emerging detection techniques for ambient bioaerosols: a review

Bioaerosols are biologically originated particles present in the atmosphere that can be formed from any process involving biological materials. They comprise of both living and non-living components including organisms, dispersal methods of organisms, and excretions. Bioaerosols such as airborne bacteria, fungal spores, pollen, and others possess diverse characteristics and effects. A large gap exists in the scientific understanding of the overall physical characteristics and measurement of bioaerosols. Consequently, this review aims to devise an appropriate approach to generate more scientific knowledge of bioaerosols. In addition to comparisons and discussions about the various factors affecting bioaerosols, sampling, handling, and the application of various devised analytical techniques, this review offers insight into the current state of bioaerosol research. The review focuses on instrumental and methodical strategies to understand bioaerosol measurement. Numerous studies have investigated conventional methods, advanced methods, and real-time methods that can be applied for bioaerosol monitoring. Each method is different in terms of working principle, characteristics, sensitivity, and efficiency. For the first time, this review explains and compares different methods of conventional, offline, online, and real-time detection methods of bioaerosols based on their working principles, sensitivity, and efficiency on a single platform. This will provide a clear concept and better options for selecting the appropriate method based on the research proposal. Furthermore, recent advances are summarized, and future outlooks are emphasized for bioaerosol identification and categorization. This study also encourages developing affordable and standardized methods to avoid the inter-laboratory and sampling variability to obtain a better understanding and comparison of bioaerosol measurements worldwide. Nevertheless, this work can assist researchers in selecting appropriate methods for bioaerosol measurement and investigation.

     

Improving the discrimination capability of bioaerosols using a dual-channel ultraviolet aerodynamic particle sizer spectrometer

We report on the results of laboratory evaluation of a dual-channel ultraviolet aerodynamic particle sizer spectrometer for real-time, continues monitoring of bio-aerosols. The detected fluorescence light was divided into two channels, simultaneously measuring the blue (400–500 nm) and green (500–600 nm) signal, which were corresponding to the fluorescence spectra of NAD(P)H and riboflavin, respectively. Primary results show the different fluorescence properties of the bacteria aerosols (Escherichia coli, Staphylococci and Bacillus subtilis var. niger spore) and the substrate (TSA eluate solutions, TSB and Nutrient broth). We demonstrated a promising method to improve the discrimination capability of bioaerosols from non-bioaerosol background components and to distinguish different types of bioaerosol particles.