The efficiency of electronic noses in detecting and identifying microorganisms has been proven by several studies. Since volatile compounds change with the growth of colonies, the identification of strains is highly dependent on the growing conditions. In this paper, the effects of growth were investigated with different species of Aspergillus, which is one of the most studied microorganisms because of its implications in environmental and food safety. For this purpose, we used an electronic nose previously utilized for volatilome detection applications and based on eight porphyrins-functionalized quartz microbalances. The volatile organic compounds (VOCs) released by cultured fungi were measured at 3, 5, and 10 days after the incubation. The signals from the sensors showed that the pattern of VOCs evolve with time. In particular, the separation between the three studied strains progressively decreases with time. The three strains could still be identified despite the influence of culture time. Linear Discriminant Analysis (LDA) showed an overall accuracy of 88% and 71% in the training and test sets, respectively. These results indicate that the presence of microorganisms is detectable with respect to background, however, the difference between the strains changes with the incubation time.
Even if slaughterhouses' workers handle large amounts of organic material and are potentially exposed to a wide range of biological agents, relatively little and not recent data are available. The main objective of this study was to characterize indoor concentrations of airborne bacteria, fungi, and endotoxin mod = Im (endotoxin∼Gram-negative*plant*filter) in two Italian poultry slaughterhouses. Air samples near air handling units inlets were also collected. Since there are not standardized protocols for endotoxin sampling and extraction procedures, an additional aim of the study was to compare the extraction efficiency of three different filter.. The study was also aimed at determining the correlation between concentrations of Gram-negative bacteria and endotoxin. In Plant A bacterial levels ranged from 17.5 to 2.6×10(3) CFU/m3. The highest concentrations were observed in evisceration area of chickens, between the automatic detachment of the neck and washing offal, and near birds coupling before hair-chilling. The highest mean value of Gram-negative (266.5 CFU/m3) was found near the washing offal of turkeys. In Plant B bacterial concentration ranged from 35 to 8×10(3) CFU/m3. The highest concentration. with the highest value of Gram-negative (248 CFU/m3), was found after defeathering. Fungal concentrations were overall lower than those found for bacteria (range: 0-205 CFU/m3 in Plant A and 0-146.2 CFU/m3 in Plant B). The microbial flora was dominated by Gram-negative and coagulase-negative staphylococci for bacteria and by species belonging to Cladosporium, Penicillium and Aspergillus genera for molds. The highest endotoxin concentrations were measured in washing offal for Plant A (range: 122.7-165.9 EU/m3) and after defeathering for Plant B (range: 0.83-38.85 EU/m3). In this study airborne microorganisms concentrations were lower than those found in similar occupational settings and below the occupational limits proposed by some authors. However, these microorganisms may exert adverse effects on exposed workers, in particular for those engaged in the early slaughtering stages, as evidenced by the presence of pathogenic species. The detection of pathogenic bacteria near AHU inlet may constitute a risk to public health and environmental pollution.
The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and characterization of airborne fungi, bacteria, endotoxin, (1,3)-β-d-glucan and animal allergens. Airborne microorganisms were collected with an air sampler and identified by microscopic and biochemical methods. Endotoxin, (1,3)-β-d-glucan, Mus m 1, Rat n 1, Can f 1, Fel d 1, Equ c 4 allergens were detected on inhalable dust samples by Kinetic LAL, Glucatell, and ELISA assays, respectively. Our data evidenced that changing cages is a determinant factor in increasing the concentration of the airborne biocontaminants; the preparation of bedding and distribution of feed, performed in the storage area, is another critical working task in terms of exposure to endotoxins (210.7 EU/m3) and (1,3)-β-d-glucans (4.3 ng/m3). The highest concentration of Mus m 1 allergen (61.5 ng/m3) was observed in the dirty washing area. The detection of expositive peaks at risk of sensitization (>2 μg/g) by Fel d 1 in animal rooms shows passive transport by operators themselves, highlighting their role as vehicle between occupational and living environments.
Nowadays only a few studies on biological and environmental risk among healthcare workers are available in literature. The present study aims to assess the health operator’s risk of contact with microorganisms during necropsy activities, to evaluate the efficiency of current protections, to identify possible new sources of contact, and to point out possible preventive measures. In addition, considering the current pandemic scenario, the risk of transmission of SARS-CoV-2 infection in the dissection room is assessed. The objectives were pursued through two distinct monitoring campaigns carried out in different periods through sampling performed both on the corpses and at the environmental level.
The peculiar characteristics of the greenhouses as confined spaces, microclimate and poor air exchange with the outside environment, encourage the development of a large number of biological agents. Endotoxin, is probably a major causative agent of occupational health problems. The objective of this study was to measure the concentrations of airborne endotoxin in greenhouses with different cultures. The influence of microclimate was studied in correlation with endotoxin levels and type of cultured vegetables. The data indicate that workers employed greenhouses are exposed to low levels of inhalable endotoxins; endotoxin concentrations do not correlate with the temperature and relative humidity values. A strong correlation between the leaf size and endotoxin concentration was observed. The mean concentration of endotoxins in the air of greenhouses is relatively low, however, there could be peaks of exposure during harvesting and eradication of broadleaf plants.
IntroductionResearchers and technicians who work with laboratory animals are exposed to animal allergens and endotoxin in the workplace. Inhalation of these bio-contaminants has been identified as a risk factor for respiratory and allergic diseases resulting in impaired lung function and laboratory animal allergy. The objective of this study was to assess the exposure to environmental endotoxin and rodent allergens to propose the control and preventive measures.MethodsThis study was conducted in an animal research facility. Stationary inhalable dust samples were collected using airChek2000 pumps equipped with IOM sampler and glass filter for endotoxin detection (Kinetic LAL assay) and with closed cassette and MCE filter for rat and mouse allergens ELISA analysis. Data were analysed by means of the statistical software R; the influence of changing cages on environmental contamination was assessed by multivariate statistical approaches (mixed effect linear regression models).ResultsThe concentration of endotoxin during changing cages increases significantly on average by a factor 1.8 with respect to the levels before or after this task (p=0.0414). Moreover, the highest concentration of endotoxin was measured during the preparation of bedding and distribution of feed. The level of Mus m 1 allergen was the most represented (mean=7.4 ng/m3, σ=16.5 ng/m3). During the changing cages was found a significant increasing of Rat n 1 and Mus m 1; Rat n 1 was also found in mouse rooms showing a contamination probably transported by the operators themselves.ConclusionThe environmental monitoring represents a powerful tool for assessing the determinant factors influencing the increase of endotoxin and animal allergen concentrations as well as underline the role of workers as passive sources of allergens. Furthermore, the identification of exposure peaks may represent an important information for the evaluation of appropriate engineering and preventive control measures particularly for workers employed in specific working tasks.
Assessment of occupational exposure to airborne endotoxins was studied for several years but still different procedures are used for sampling and analysis. Among analytical methods LAL test is the most used. A different approach is represented by chemical analyses, based on the detection of the β-hydroxy fatty acids, as markers of lipopolysaccharide (LPS). In this study an analytical method using HPLC-MS/MS was applied to quantify the content of β-hydroxy-dodecanoic (3-OH C 12 ) and β-hydroxytetradecanoic (3-OH C 14 ) acids in thirteen Gram-negative bacterial strains. In order to compare biological and chemical results cell suspensions were analyzed also by Kinetic Chromogenic LAL test. The results obtained by HPLC-MS/MS show that three samples did not contain 3-OH C 12 at all, while 3-OH C 14 was measured in a concentration range from 11.1 to 4007.5µg/L. Endotoxin concentration measured by LAL assay was in the range of 10 2 -10 3 µg/L. Pearson's test showed that the sum of fatty acids by HPLC-MS/MS correlates positively with the LAL Test (r= 0.79) confirming that it can be considered a reliable marker of endotoxin contamination. Principal Component Analysis (PCA) confirms above results and provides additional information grouping microorganisms related with each other on the basis of their biochemical features, habitat and disease spectra.
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