Association Between Levels of Radon And Bioaerosols (Bacteria And Fungi) By Living Conditions

This study aimed to measure the levels of airborne radon (Rn) and bioaerosols—culturable airborne bacteria (CAB) and culturable airborne fungi (CAF)—in South Korea’s residential environments, considering living conditions such as the number of ventilations, number of windows, floors, temperature, and relative humidity. These levels were evaluated for 32 houses of residents from the socially vulnerable class. Rn gas and bioaerosols were sampled twice: in fall and summer. A self-report survey gathered residents’ information on their general characteristics (daily residence time, heating and cooking type, cleaning and washing cycle, etc.) and health condition scores (0–100 points) on the day of sampling. The range of Rn levels was 0.43–7.439 pCi/L with a median of 0.70 pCi/L. The CAB levels were 239–488 colony-forming unit (CFU)/m3 with a median of 309 CFU/m3, and CAF levels were 174–366 CFU/m3 with a median of 233 CFU/m3. Thus, this study found that semi-basement residential indoor environments negatively affected Rn and bioaerosol levels, and living in such residences resulted in high health condition scores.

Microscopic Fungi in Big Cities: Biodiversity, Source, and Relation to Pollution by Potentially Toxic Metals

For the first time, a mycological analysis of outdoor urban environment (air, leaves, sealed surfaces) was carried in the cities of subarctic (Murmansk) and temperate (Moscow) climatic zones. The chemical composition of dust deposited on leaves of dominant tree species was taken as an indicator of the air quality. Assessment of the complex impact of factors (climate zone, type of substrate, anthropogenic load) on the quantitative and qualitative parameters of mycobiome was performed. Compared to Moscow, Murmansk was characterized by an increased number and concentrations of pollutants in the deposited dust. The number of culturable airborne fungi in Murmansk was substantially lower than in Moscow. Half of the species belonged to the opportunistic in both cities. Most dangerous opportunistic fungi were absent in the air of recreational zones but present on leaves surface and in road dust in all assessed zones of the cities. Dust chemical composition affected the diversity of fungi species. While the relationship of biological parameters with concentration of potentially toxic metals was generally negative, Cd increased the fraction of opportunistic fungi in road dust. The study revealed an importance of substrate in determining the sensitivity of outdoor mycobiome to pollution and highlighted its biological characteristics sensitive to climate.

On the nature of indoor airborne bioaerosols at a hospital in Iran

Introduction: Hospitals are sensitive places owing to the contagious nature of diseases transferred by patients to others such as health care workers and staff. Materials and methods: The aim of the present work is to evaluate the type and concentration of bacterial and fungal bio-aerosols in the indoor air of four operating rooms (ORs) and four wards in Khalkhal, Iran during 2019. A total of 192 bacterial and fungal samples were collected. Results: Mean total concentrations of airborne bacteria for ORs and wards were between 11±1.2 to 48±3.1 CFU/m3, respectively, while for airborne fungi values ranged from 95±5.6 to 51±1.2 CFU/m3, respectively. The predominant genera of airborne bacterial isolated (ORs vs. wards) were Staphylococcus epidermidis (72% vs. 58%), Group D Streptococcus (4% vs. 17%), Group A Streptococcus (13% vs. 3%), and Staphylococcus saprophyticus (6% vs. 4%). In addition, the main fungal species identified (ORs vs. wards) were Cladosporium sp. (37% vs. 38%), Penicillium sp. (28% vs. 22%), and Aspergillus Niger (21% vs. 12%). A statistically significant correlation was observed between the mean concentration of bio-aerosols and population density (p<0.05). Conclusion: Furthermore, a statistically significant difference was observed between the mean concentrations of bio-aerosols and the values recommended by WHO (p<0.05), linked presumably to inadequate disinfection, improper design and operation of standard central ventilation (SCV), and the high density of visitors and patients. Addressing such issues can help reduce airborne fungi and bacteria in hospital.

ISOLATION AND IDENTIFICATION OF VEGETABLE MARKET AEROMYCOFLORA FROM THE ENVIRONMENT OF WARDHA CITY

Airborne fungi behaves as an indicators of the levels of atmospheric biopollutants. The study was carried out during the period of March 2017- February 2018. The fungi were isolated from the area of vegetable market of Wardha city. The exposed petriplate method were used for the isolation of fungi from morning and evening hours and humidity and temperatures were recorded regularly. Total 835 and 800 fungal colonies were recorded during one-year study period and they were belonging to 95 fungal species. The fungus Cladosporium cladosporoides, C. herbarum, A.niger ,A. flavus, A. nidulans, A.fumigatus was the prevalent isolated types from vegetable market area of Wardha city from morning and evening hours. Maximum percentage contribution of fungal colonies was observed at morning and evening hours during rainy (41.43%), (40.05%) and winter season (39.64%), (41.16%) followed by summer season (18.92%), (18.03) respectively

RNA-Based Analysis Reveals High Diversity of Plant-Associated Active Fungi in the Atmosphere

Fungi are ubiquitous in nature; that is, they are present everywhere on the planet; understanding the active state and functional capacity of airborne microbes associated with health of human, animal, and plant is critical for biosafety management. Here, we firstly and directly proved that there were about 40% active fungi in the air via rRNA amplicon sequencing and imaging flow cytometry simultaneously. Amplicon sequencing analysis showed differences between structures of active and total fungal community; Ascomycota were dominant in the active community, while Basidiomycota have low transcriptional activity across all samples. Notably, plant pathogenic fungi were predominant in the air, and more than 50% were active, including not only several common plant pathogens but also biotrophic fungi (Erysiphe sp. and Microbotryum sp.) and host-specific pathogens, which were generally considered to be inactive after leaving the host. Putative plant pathogens of eight genera were found active across the sampling season, indicating their superior ability to obtain nutrients even in barren nutrient environments. Interestingly, we detected several potentially active unrecorded fungi in China (Diatrype prominens, Septofusidium herbarum, Pseudomicrostroma glucosiphilum, and Uromycladium tepperianum), which suggested that they spread over a long distance by air and may cause diseases under favorable conditions. Our results suggested that maintaining transmission in air is an essential feature of many fungi including plant pathogens regardless of being a biotrophic, hemibiotrophic, or necrotrophic group. Moreover, two potentially active human pathogens and one animal pathogen were captured, which indicated their potential risks. This study provided a new perspective for more comprehensive understanding of airborne fungi, including their multidimensional lifestyle, state, functioning, and potential pathogenic risk. It also laid the foundation for further prediction and management of airborne microbial communities, which would be of interest for public health and agriculture.

Evaluation of Antimicrobial Effect of Zinc Pyrithione against Airborne Fungi and Bacteria Growth Collected onto New and Loaded HVAC Fibrous Filters

Microbial growth onto HVAC filters was observed in real conditions with possible degradation of the indoor air quality. The filtration performance of marketed antimicrobial filters containing zinc pyrithione was tested under laboratory conditions and compared to that of similar filters with the same classification, F7 (EN779:2002). The filtration performance of the two tested filters during loading with PM10 particles was quantified in an experimental setup with filter pressure drop measurement and particle counting upstream and downstream of the filters. The microbial growth on the new and loaded filters, both contaminated with a microbial airborne consortium composed of two bacteria (Gram-positive and -negative) and fungi, was quantified by colony-forming units after conditioning the filters for a few days under controlled temperature (25 °C) and humidity (50% or 90% relative humidity). The results reveal that there was no degradation of the filtration performance of the filters treated with the antimicrobial agent. The efficiency of the antimicrobial treatment, i.e., the ability to inhibit the growth of microorganisms during the incubation period, was significant with the new filters regarding the fungal growth, but the results demonstrate that the antimicrobial treatment became inefficient with the loaded filters.

Airborne Fungi in Prison Indoor Environments of Nsukka and Enugu Metropolis, Nigeria

Air borne fungi are transmitted through the air which can cause respiratory infections in human leading to allergies, asthma and diseases of the respiratory tract. The study is to determine the prevalence of fungi isolates in Enugu and Nsukka indoor prison environments and the possible effects on the respiratory tracts of the prison inmates. Institutions that accommodate large number of people such as Prisons, schools and hospitals are prone to airborne diseases due to overcrowded and unhygienic environment. The study was carried out using convenience sampling method and health based questionnaires. One hundred and forty (140)samples were analyzed consisting prison offices(48),inmates cells (28),lavatory (16),furniture(8),nasal swabs(20) and hostels(20). AC single impactor with high vacuum pump was used for indoor air sample collection; thermometer was used in measuring the temperature of the room and hygrometer for measuring the humidity. Sterile swab was used in collection of nasal samples, walls, furniture, toilets and bathrooms. Sabouraund dextrose agar (0.05µg Chloramphenicol and 1µg of Streptomycin), Malt extract agar, Chromagar, Brain heart infusion agar, and Nutrient agar were used for culture media for isolation of fungi respectively. The data generated from this research was analyzed using SPSS statistical software version 23.The result obtained showed that the percentage distribution of fungi isolates in prison offices were 60.9%, 57.4% in Nsukka and Enugu respectively while the percentage distribution percentage distribution of fungi isolates in prison cells were 42.6% and 39.1% in Enugu and Nsukka respectively. There was a significant difference in the distribution of fungal isolates at P=0.042.The indoor temperature and humidity of Enugu and Nsukka were the same at P using ANOVA, when compared with the hostels that served as control. Considering the public health effects of these airborne fungi, appropriate measures should be put in place in prison indoor environment to prevent the growth of moulds and yeast and its dissemination.