Microbiological evaluation of ten French archives and link to occupational symptoms

Unveiling the Occupational Exposure to Microbial Contamination in Conservation–Restoration Settings

Assuring a proper environment for the fulfillment of professional activities is one of the Sustainable Development Goals and is contemplated in the One Health approach assumed by the World Health Organization. This particular study is applied to an often neglected sector of our society—the conservators/restorers—despite the many health issues reported by these professionals. Three different specialties (textiles, paintings and wood sculpture) and locations were selected for evaluation by placement of electrostatic dust cloths. After treatment of the samples, bacterial and fungal contamination were assessed, as well as mycotoxin determination, the presence of azole-resistant strains and cytotoxicity of the microorganisms encountered. Bacteria were only present in one of medias used and showed relatively low numbers. The highest level of contamination by fungi was identified in one of the textiles settings. The textile area also showed the highest variability for fungi. Aspergillus sp. are one indicator of possible environmental issues, and A. sections Fumigati and Circumdati were particularly relevant in two of the settings and identified in all of them. No mycotoxins were detected and the large majority of the fungi identified were non-cytotoxic. Overall, these can be considered low-contaminated environments but attention should be given to the Aspergillus sp. contamination. Additional studies are needed not only to make these results more robust, but also to test if the environmental sampling alone is the best approach in a setting where there is very little movement and dust displacement and where professionals are in very close proximity to the artefacts being treated, which may suggest the existence of a micro-atmosphere worth evaluating and comparing to the obtained results.

Air- and dustborne fungi in repositories of the National Archive of the Republic of Cuba

This study has as objectives to determine the concentration and diversity of the air- and dustborne mycobiota in seven National Archive of the Republic of Cuba repositories, and to assess the potential risk of biodeterioration that isolated taxa may have. In the indoor and outdoor environmental microbiological samplings a SAS biocollector was used and the indoor/outdoor (I/O) ratio was determined for each repository. The settled dust was collected during six months. Sørensen's coefficient of similarity (QS) was calculated to compare the isolated taxa among the three studied niches (indoor air, dust, outdoor air). The biodegradation potential of the isolated taxa was determined by semi-quantitative tests. The concentrations in the air of repositories with natural cross-ventilation ranged from 225.2-750.3 CFU m-3, while in the Map library with air-conditioning the concentration was significantly lower. The I/O ratios ranged from 0.1-1.7 revealing different environmental qualities. The maximum settled dust load was 22.8 mg/m2/day with a top fungal concentration of 6000 CFU g-1. 14 and eleven genera were detected in the air and dust respectively with predominance of the genera Aspergillus, Cladosporium and Penicillium. A QS of 0.8 was obtained between the indoor and the outdoor environments with eleven taxa similar evidencing the incidence of outdoors on the indoor mycobiota. The isolated taxa showed several biodeteriogenic attributes highlighting twelve and 14 taxa from indoor air and dust respectively with positive results for the five tests performed. This demonstrates the potential risk that fungal environmental represent for the preserved documentary heritage.

Survey of 1012 moldy dwellings by culture fungal analysis: Threshold proposal for asthmatic patient management

Different countries have tried to define guidelines to quantify what levels of fungi are considered as inappropriate for housing. This retrospective study analyzes indoor fungi by cultures of airborne samples from 1012 dwellings. Altogether, 908 patients suffering from rhinitis, conjunctivitis, and asthma were compared to 104 controls free of allergies. Portuguese decree law no 118/2013 (PDL118), ANSES (a French environmental and health agency) recommendations, and health regulations of Besançon University Hospital were applied to determine the rates of non-conforming dwellings, which were respectively 55.2%, 5.2%, and 19%. Environmental microbiological results and medical data were compared. The whole number of colonies per cubic meter of air was correlated with asthma (P < 0.001) and rhinitis (P = 0.002). Sixty-seven genera and species were detected in bedrooms. Asthma was correlated to Aspergillus versicolor (P = 0.004) and Cladosporium spp. (P = 0.02). Thresholds of 300 cfu/m³ for A. versicolor or 495 cfu/m³ for Cladosporium spp. are able to discriminate 90% of the asthmatic dwellings. We propose a new protocol to obtain an optimal cost for indoor fungi surveys, excluding surface analyses, and a new guideline to interpret the results based on >1000 cfu/m³ of whole colonies and/or above threshold levels for A. versicolor or Cladosporium spp.

Seasonal diversity of biodeteriogenic, pathogenic, and toxigenic constituents of airborne mycobiota in a sacral environment

The main purpose of this study was to isolate airborne fungi and assess seasonal variations in air contamination with their particulates by determining the levels of their propagules in the nave and exonarthex of a church. We also monitored indoor microclimate as a determining factor for fungal proliferation on wall paintings, spore release, and transmission through the air. The temperature and relative humidity of the nave favoured fungal growth. A total of 33 fungi were isolated, mainly of the phylum Ascomycota, and to the lesser extent of the phyla Zygomycota and Basidiomycota. The most common were the fungi of the genera Penicillium and Aspergillus (23.55 % and 20.58 %, respectively). Sørensen's quotient of similarity (0.37) suggests moderate species overlap and constant exchange of fungal propagules between the nave and exonarthex. The autumn had the highest diversity, with 17 documented taxa, followed by the summer and the winter. The spring had only eight taxa. Quantitative analysis of the airborne mycobiota in the nave (430±84.85 to 1880±106.07 CFU m-3) and exonarthex (715±59.62 to 2295±91.92 CFU m-3) showed very high contamination throughout the year, with values exceeding the maximum permissible concentrations by most standards. Many of the fungi determined in this study are known for their biodeteriogenic, toxigenic, and allergenic properties, and are a threat not only to occasional visitors and staff, but also to valuable works of art decorating nave walls.

Lack of evidence of IgE allergic sensitisation from working with lactic acid bacteria in the dairy foods industry

This research communication aimed to evaluate the level of immunoglobulin E from lactic acid bacteria (LAB) that are used in dairy industries. Previous studies have demonstrated that workers report symptoms of irritation and are frequently IgG-sensitised to LAB. Workers (n = 44) from a probiotic production unity and the control lab were seen by a medical practitioner and responded to an occupational questionnaire. Specific IgE by the DELFIA® technique against 6 strains of LAB were measured on 44 exposed workers and 31 controls sera. Levels of specific IgE were low and no difference was observed between the two groups. This lack of IgE response could be explained by a healthy worker effect, an efficient implementation of personal protective equipment or by an absence of allergic mechanisms to account for the self-reported irritative symptoms. Despite the high concentrations of LAB, preventive measures are effective enough to guarantee no allergic effect and to prevent other adverse health effects. The implementation of preventive measures to avoid or reduce exposure to dust of LAB, and more generally to milk powder, is recommended in all dairy industry.

Bulk isolation of basidiospores from wild mushrooms by electrostatic attraction with low risk of microbial contaminations

The basidiospores of most Agaricomycetes are ballistospores. They are propelled off from their basidia at maturity when Buller's drop develops at high humidity at the hilar spore appendix and fuses with a liquid film formed on the adaxial side of the spore. Spores are catapulted into the free air space between hymenia and fall then out of the mushroom's cap by gravity. Here we show for 66 different species that ballistospores from mushrooms can be attracted against gravity to electrostatic charged plastic surfaces. Charges on basidiospores can influence this effect. We used this feature to selectively collect basidiospores in sterile plastic Petri-dish lids from mushrooms which were positioned upside-down onto wet paper tissues for spore release into the air. Bulks of 10⁴ to >10⁷ spores were obtained overnight in the plastic lids above the reversed fruiting bodies, between 10⁴ and 10⁶ spores already after 2-4 h incubation. In plating tests on agar medium, we rarely observed in the harvested spore solutions contaminations by other fungi (mostly none to up to in 10% of samples in different test series) and infrequently by bacteria (in between 0 and 22% of samples of test series) which could mostly be suppressed by bactericides. We thus show that it is possible to obtain clean basidiospore samples from wild mushrooms. The technique of spore collection through electrostatic attraction in plastic lids is applicable to fresh lamellate and poroid fruiting bodies from the wild, to short-lived deliquescent mushrooms, to older and dehydrating fleshy fruiting bodies, even to animal-infested mushrooms and also to dry specimens of long-lasting tough species such as Schizophyllum commune.

Endotoxin, ergosterol, muramic acid and fungal DNA in dust from schools in Johor Bahru, Malaysia--Associations with rhinitis and sick building syndrome (SBS) in junior high school students

This paper studied associations between ocular symptoms, rhinitis, throat and dermal symptoms, headache and fatigue in students by ethnicity and in relation to exposure to chemical microbial markers and fungal DNA in vacuumed dust in schools in Malaysia. A total of 462 students from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated (96% response rate). Dust was vacuumed from 32 classrooms and analysed for levels of five types of endotoxin as 3-hydroxy fatty acids (C10, C12, C14, C16 and C18 3-OH), muramic acid, ergosterol and five sequences of fungal DNA. Multiple logistic regression was applied. Totally 11.9% reported weekly ocular symptoms, 18.8% rhinitis, 15.6% throat and 11.1% dermal symptoms, 20.6% headache and 22.1% tiredness. Totally 21.1% reported pollen or furry pet allergy (atopy) and 22.0% parental asthma or allergy. Chinese students had less headache than Malay and Indian had less rhinitis and less tiredness than Malay. Parental asthma/allergy was a risk factor for ocular (odds ratio=3.79) and rhinitis symptoms (OR=3.48). Atopy was a risk factor for throat symptoms (OR=2.66), headache (OR=2.13) and tiredness (OR=2.02). There were positive associations between amount of fine dust in the dust samples and ocular symptoms (p<0.001) and rhinitis (p=0.006). There were positive associations between C14 3-OH and rhinitis (p<0.001) and between C18 3-OH and dermal symptoms (p=0.007). There were negative (protective) associations between levels of total endotoxin (LPS) (p=0.004) and levels of ergosterol (p=0.03) and rhinitis and between C12 3-OH and throat symptoms (p=0.004). In conclusion, the amount of fine dust in the classroom was associated with rhinitis and other SBS symptoms and improved cleaning of the schools is important. Endotoxin in the school dust seems to be mainly protective for rhinitis and throat symptoms but different types of endotoxin could have different effects. The ethnic differences in symptoms among the students deserve further attention.

Rhinitis, Ocular, Throat and Dermal Symptoms, Headache and Tiredness among Students in Schools from Johor Bahru, Malaysia: Associations with Fungal DNA and Mycotoxins in Classroom Dust

There are few studies on rhinitis and sick building syndrome (SBS) among students in tropical countries. We studied associations between levels of five fungal DNA sequences, two mycotoxins (sterigmatocystin and verrucarol) and cat allergen (Fel d 1) levels in schools and rhinitis and other weekly SBS symptoms in the students. Fungal DNA was measured by quantitative PCR and cat allergen by ELISA. Pupils (N = 462) from eight randomly selected schools in Johor Bahru, Malaysia participated (96%). Dust samples were collected by cotton swabs and Petri dishes exposed for one week. None of the schools had a mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures and indoor CO2 levels were low (mean 492 ppm; range 380-690 ppm). Weekly nasal symptoms (rhinitis) (18.8%), ocular (11.6%), throat (11.1%), dermal symptoms, headache (20.6%) and tiredness (22.1%) were common. Total fungal DNA in swab samples was associated with rhinitis (p = 0.02), ocular symptoms (p = 0.009) and tiredness (p = 0.001). There were positive associations between Aspergillus versicolor DNA in Petri dish samples, ocular symptoms (p = 0.02) and tiredness (p = 0.001). The level of the mycotoxin verrucarol (produced by Stachybotrys chartarum) in swab samples was positively associated with tiredness (p = 0.04). Streptomyces DNA in swab samples (p = 0.03) and Petri dish samples (p = 0.03) were negatively associated with tiredness. In conclusion, total fungal contamination, measured as total fungal DNA) in the classrooms, Aspergillus versicolor and verrucarol can be risk factors for rhinitis and SBS symptoms among students in the tropical country Malaysia.

Airborne microorganisms cultivable on naturally ventilated document repositories of the National Archive of Cuba

The quality of the indoor air can provide very useful information for the artwork conservation. The aim of the study was to evaluate the microbial concentration inside six document repositories of the National Archive of the Republic of Cuba in two months of 1 year. The repositories are large, high, and have a natural cross-ventilation system. The microbial sampling was done in July 2010 (summer or rainy month) and February 2011 (winter or dry month) using the SAS Super 100 biocollector at 100 L/min. An appropriate selective culture media were used to isolate fungi and bacteria. A high total microbial concentration on the north side of the building in two studied months was observed. The fungal concentrations were significantly higher in July 2010 in all repositories, while the bacterial concentrations were significantly higher mostly in February 2011 only in repositories located on the first and second floor of the building. Eight fungal genera in the indoor air of all environments were isolated. Regardless of the side of the analyzed building, Penicillium, Aspergillus, and Cladosporium were the predominant genera. Aspergillus flavus and Aspergillus niger were the species isolated in almost all of the analyzed repositories in the studied months. Gram-positive bacteria prevailed among bacterial groups isolated from indoor air repositories, and some percentages corresponded to the genera Bacillus and Streptomyces. In Cuba, the temperature and relative humidity are high during the whole year but the natural ventilation plays an important role in retarding microbial growth on materials.