Fungal pollution of indoor environments and its management

In silico approaches for the identification of potential allergens among hypothetical proteins from Alternaria alternata and its functional annotation

Direct exposure to the fungal species Alternaria alternata is a major risk factor for the development of asthma, allergic rhinitis, and inflammation. As of November 23rd 2020, the NCBI protein database showed 11,227 proteins from A. alternata genome as hypothetical proteins (HPs). Allergens are the main causative of several life-threatening diseases, especially in fungal infections. Therefore, the main aim of the study is to identify the potentially allergenic inducible proteins from the HPs in A. alternata and their associated functional assignment for the complete understanding of the complex biological systems at the molecular level. AlgPred and Structural Database of Allergenic Proteins (SDAP) were used for the prediction of potential allergens from the HPs of A. alternata. While analyzing the proteome data, 29 potential allergens were predicted by AlgPred and further screening in SDAP confirmed the allergic response of 10 proteins. Extensive bioinformatics tools including protein family classification, sequence-function relationship, protein motif discovery, pathway interactions, and intrinsic features from the amino acid sequence were used to successfully predict the probable functions of the 10 HPs. The functions of the HPs are characterized as chitin-binding, ribosomal protein P1, thaumatin, glycosyl hydrolase, and NOB1 proteins. The subcellular localization and signal peptide prediction of these 10 proteins has further provided additional information on localization and function. The allergens prediction and functional annotation of the 10 proteins may facilitate a better understanding of the allergenic mechanism of A. alternata in asthma and other diseases. The functional domain level insights and predicted structural features of the allergenic proteins help to understand the pathogenesis and host immune tolerance. The outcomes of the study would aid in the development of specific drugs to combat A. alternata infections.

A Scoping Review on Fungus and Mycotoxin Studies in the Building's Environment: Mycotoxin Analysis by Mass Spectrometry

It has been well-established that mycotoxins are poisonous chemical metabolites secreted by certain molds. Some of them significantly affect the health of humans and livestock. Increasing attention is now being paid to uncovering and identifying mycotoxins' presence in the building's environment. However, the main challenge remains in suitable and reliable analytical methods for their identification and detection in infected structures. GC-MS and LC-MS/MS techniques have been used extensively for mycotoxin analysis, and advancement in these techniques enabled a more comprehensive range of mycotoxins to be detected. As such, this study aimed to address a brief overview of various phenomena of existing sample collection, preparation, and analysis to detect mycotoxins in the building's environment. This scoping review includes articles from 2010 to 2020 available from PubMed, Scopus, Cochrane, Wiley, Google Scholar, and ScienceDirect. Duplicate articles were removed, and exclusion criteria were applied to eliminate unrelated studies, resulting in 14 eligible articles. The present study provides an overview of mycotoxin analysis by GC-MS and LC-MS/MS in buildings. Many techniques are available for analyzing and detecting multiple mycotoxins using these methods. Future efforts would focus on rapid assays and tools enabling measuring a broader range of mycotoxins in a single matrix and lower detection limits. In addition, it would assist future findings on new techniques and mycotoxins that existed in the building's environment.

A comprehensive review of microbial contamination in the indoor environment: sources, sampling, health risks, and mitigation strategies

The quality of the indoor environment significantly impacts human health and productivity, especially given the amount of time individuals spend indoors globally. While chemical pollutants have been a focus of indoor air quality research, microbial contaminants also have a significant bearing on indoor air quality. This review provides a comprehensive overview of microbial contamination in built environments, covering sources, sampling strategies, and analysis methods. Microbial contamination has various origins, including human occupants, pets, and the outdoor environment. Sampling strategies for indoor microbial contamination include air, surface, and dust sampling, and various analysis methods are used to assess microbial diversity and complexity in indoor environments. The review also discusses the health risks associated with microbial contaminants, including bacteria, fungi, and viruses, and their products in indoor air, highlighting the need for evidence-based studies that can relate to specific health conditions. The importance of indoor air quality is emphasized from the perspective of the COVID-19 pandemic. A section of the review highlights the knowledge gap related to microbiological burden in indoor environments in developing countries, using India as a representative example. Finally, potential mitigation strategies to improve microbiological indoor air quality are briefly reviewed.

Relationship Between Airborne Fungi Presence and the Position of the High Efficiency Particulate Air Filter in the Heating, Ventilation, and Air Conditioning System

AIM

Establish the influence of the terminal or nonterminal position of High Efficiency Particulate Air (HEPA) filters in the Heating, Ventilation, and Air Conditioning (HVAC) system on the presence of airborne fungi in controlled environment rooms.

BACKGROUND

Fungal infections are an important cause of morbidity and mortality in hospitalized patients.

METHODS

This study was realized from 2010 to 2017, in rooms with terminal and nonterminal HEPA filters, in eight Spanish hospitals. In rooms with terminal HEPA filters, 2,053 and 2,049 samples were recollected, and in rooms with nonterminal HEPA filters, 430 and 428 samples were recollected in the air discharge outlet (Point 1) and in the center of the room (Point 2), respectively. Temperature, relative humidity, air changes per hour, and differential pressure were recollected.

RESULTS

Multivariable analysis showed higher odds ratio (OR) of airborne fungi presence when HEPA filters were in nonterminal position (OR: 6.78; 95% CI [3.77, 12.20]) in Point 1 and (OR: 4.43; 95% CI [2.65, 7.40]) in Point 2. Other parameters influenced airborne fungi presence, such as temperature (OR: 1.23; 95% CI [1.06, 1.41]) in Point 2 differential pressure (OR: 0.86; 95% CI [0.84, 0.90]) and (OR: 0.88; 95% CI [0.86, 0.91]) in Points 1 and 2, respectively.

CONCLUSIONS

HEPA filter in terminal position of the HVAC system reduces the presence of airborne fungi. To decrease the presence of airborne fungi, adequate maintenance of the environmental and design parameters is necessary in addition to the terminal position of the HEPA filter.

Research on Thermal Insulation Performance and Impact on Indoor Air Quality of Cellulose-Based Thermal Insulation Materials

Worldwide, the need for thermal insulation materials used to increase the energy performance of buildings and ensure indoor thermal comfort is constantly growing. There are several traditional, well-known and frequently used thermal insulation materials on the building materials market, but there is a growing trend towards innovative materials based on agro-industrial waste. This paper analyses the performance of 10 such innovative thermal insulation materials obtained by recycling cellulosic and/or animal waste, using standardised testing methods. More precisely, thermal insulation materials based on the following raw materials were analysed: cellulose acetate, cigarette filter manufacturing waste; cellulose acetate, cigarette filter manufacturing waste and cigarette paper waste; cellulose acetate, waste from cigarette filter manufacturing, waste cigarette paper and waste aluminised paper; cellulose from waste paper (two types made by two independent manufacturers); wood fibres; cellulose from cardboard waste; cellulose from waste cardboard, poor processing, inhomogeneous product; rice husk waste and composite based on sheep wool, recycled PET fibres and cellulosic fibres for the textile industry. The analysis followed the performance in terms of thermal insulating quality, evidenced by the thermal conductivity coefficient (used as a measurable indicator) determined for both dry and conditioned material at 50% RH, in several density variants, simulating the subsidence under its own weight or under various possible stresses arising in use. The results showed in most cases that an increase in material density has beneficial effects by reducing the coefficient of thermal conductivity, but exceptions were also reported. In conjunction with this parameter, the analysis of the 10 types of materials also looked at their moisture sorption/desorption capacity (using as a measurable indicator the amount of water stored by the material), concluding that, although they have a capacity to regulate the humidity of the indoor air, under low RH conditions the water loss is not complete, leaving a residual quantity of material that could favour the development of mould. Therefore, the impact on indoor air quality was also analysed by assessing the risk of mould growth (using as a measurable indicator the class and performance category of the material in terms of nutrient content conducive to the growth of microorganisms) under high humidity conditions but also the resistance to the action of two commonly encountered moulds, Aspergillus niger and Penicillium notatum. The results showed a relative resistance to the action of microbiological factors, indicating however the need for intensified biocidal treatment.

Study on the Possibilities of Developing Cementitious or Geopolymer Composite Materials with Specific Performances by Exploiting the Photocatalytic Properties of TiO2 Nanoparticles

Starting from the context of the principles of Sustainable Development and Circular Economy concepts, the paper presents a synthesis of research in the field of the development of materials of interest, such as cementitious composites or alkali-activated geopolymers. Based on the reviewed literature, the influence of compositional or technological factors on the physical-mechanical performance, self-healing capacity and biocidal capacity obtained was analyzed. The inclusion of TiO₂ nanoparticles in the matrix increase the performances of cementitious composites, producing a self-cleaning capacity and an anti-microbial biocidal mechanism. As an alternative, the self-cleaning capacity can be achieved through geopolymerization, which provides a similar biocidal mechanism. The results of the research carried out indicate the real and growing interest for the development of these materials but also the existence of some elements still controversial or insufficiently analyzed, therefore concluding the need for further research in these areas. The scientific contribution of this study consists of bringing together two apparently distinct research directions in order to identify convergent points, to create a favorable framework for the development of an area of research little addressed so far, namely, the development of innovative building materials by combining improved performance with the possibility of reducing environmental impact, awareness and implementation of the concept of a Circular Economy.

Critical review on emerging health effects associated with the indoor air quality and its sustainable management

Indoor air quality (IAQ) is one of the fundamental elements affecting people's health and well-being. Currently, there is a lack of awareness among people about the quantification, identification, and possible health effects of IAQ. Airborne pollutants such as volatile organic compounds (VOCs), particulate matter (PM), sulfur dioxide (SO2), carbon monoxide (CO), nitrous oxide (NO), polycyclic aromatic hydrocarbons (PAHs) microbial spores, pollen, allergens, etc. primarily contribute to IAQ deterioration. This review discusses the sources of major indoor air pollutants, molecular toxicity mechanisms, and their effects on cardiovascular, ocular, neurological, women, and foetal health. Additionally, contemporary strategies and sustainable methods for regulating and reducing pollutant concentrations are emphasized, and current initiatives to address and enhance IAQ are explored, along with their unique advantages and potentials. Due to their longer exposure times and particular physical characteristics, women and children are more at risk for poor indoor air quality. By triggering many toxicity mechanisms, including oxidative stress, DNA methylation, epigenetic modifications, and gene activation, indoor air pollution can cause a range of health issues. Low birth weight, acute lower respiratory tract infections, Sick building syndromes (SBS), and early death are more prevalent in exposed residents. On the other hand, the main causes of incapacity and early mortality are lung cancer, chronic obstructive pulmonary disease, and cardiovascular disorders. It's crucial to acknowledge anticipated research needs and implemented efficient interventions and policies to lower health hazards.

Fungal Contamination of Building Materials and the Aerosolization of Particles and Toxins in Indoor Air and Their Associated Risks to Health: A Review

It is now well established that biological pollution is a major cause of the degradation of indoor air quality. It has been shown that microbial communities from the outdoors may significantly impact the communities detected indoors. One can reasonably assume that the fungal contamination of the surfaces of building materials and their release into indoor air may also significantly impact indoor air quality. Fungi are well known as common contaminants of the indoor environment with the ability to grow on many types of building materials and to subsequently release biological particles into the indoor air. The aerosolization of allergenic compounds or mycotoxins borne by fungal particles or vehiculated by dust may have a direct impact on the occupant’s health. However, to date, very few studies have investigated such an impact. The present paper reviewed the available data on indoor fungal contamination in different types of buildings with the aim of highlighting the direct connections between the growth on indoor building materials and the degradation of indoor air quality through the aerosolization of mycotoxins. Some studies showed that average airborne fungal spore concentrations were higher in buildings where mould was a contaminant than in normal buildings and that there was a strong association between fungal contamination and health problems for occupants. In addition, the most frequent fungal species on surfaces are also those most commonly identified in indoor air, regardless the geographical location in Europe or the USA. Some fungal species contaminating the indoors may be dangerous for human health as they produce mycotoxins. These contaminants, when aerosolized with fungal particles, can be inhaled and may endanger human health. However, it appears that more work is needed to characterize the direct impact of surface contamination on the airborne fungal particle concentration. In addition, fungal species growing in buildings and their known mycotoxins are different from those contaminating foods. This is why further in situ studies to identify fungal contaminants at the species level and to quantify their average concentration on both surfaces and in the air are needed to be better predict health risks due to mycotoxin aerosolization.

Emissions of Fungal Volatile Organic Compounds in Residential Environments and Temporal Emission Patterns: Implications for Sampling Methods

Currently, little is known about the occurrences of fungi-derived microbial volatile organic compounds (mVOCs) in various indoor materials and their detection in residential environments, despite mVOCs being linked to several acute health effects. We identified various mVOCs emitted from fungi grown on PVC wallpaper, silicone rubber, and malt extract agar. We also investigated mVOCs temporal emission and whether fungi-derived VOCs concentration can be used to estimate fungal concentration in the air using active and passive air sampling methods. Among the three fungal growth media included in this study, silicone rubber produced the most variety of mVOCs: 106 compounds (from Aspergillus niger), 35 compounds (from Alternaria alternata), and 85 compounds (from Penicillium chrysogenum). We also found the emission patterns of eight chemical classes (i.e., aromatics, ethers, aliphatics, alcohols, ketones, aldehydes, chlorides, and nitrides) from the three different fungi. From the results of our field experiments in 11 residential environments, passive air samplers led to higher correlations coefficients (0.08 to 0.86) between mVOCs' air concentrations and airborne fungal concentrations, compared with active air samplers, which showed negative correlation coefficients (-0.99 to -0.02) for most compounds. This study elucidated the occurrence and temporal emission patterns of fungal VOCs in residential environments.

Impact of Cellulolytic Fungi on Biodegradation of Hemp Shives and Corn Starch-Based Composites with Different Flame-Retardants

Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulating or structural building materials. Therefore, they must be stable during exploitation. However, BcBs are exposed to microorganisms present in the environment, and it is of great interest to investigate the biodegradation behaviour of these materials. This work identified microorganisms growing on BcBs that contain either Flovan CGN or expandable graphite as flame retardants and selected fungi such as Rhizopus oryzae and Aspergillus fumigatus to test the way they affect the materials of interest. For this purpose, the enzymatic activity of cellulases and amylases produced by these organisms were determined. In addition, the apparent density as well as compressive strength of the affected boards were evaluated. The results showed that apparent density and compressive strength deteriorated in BcB composition with the Flovan CGN flame retardant. At the same time, the level of deterioration was lower when the expandable graphite was used, suggesting that it also acts as an antimicrobial agent. A scanning electronic microscopy analysis was employed to monitor the growth of microorganisms in the BcBs. Such analysis demonstrated that, regardless of BcB composition, fungi easily penetrate into the middle layers of the material.

CORRELATION BETWEEN FARMER'S RESPIRATORY HEALTH AND INDOOR AIR QUALITY IN PULOKERTO AND SUNGAI REBO WETLAND AREA

Wetland areas have humid temperatures and residential development will have a major effect on the air quality in the room which becomes humid and humid room air can cause several symptoms of respiratory disorders caused by airborne. This research was conducted in 35 farmer's houses which aims to determine the relationship between the respiratory health of farmers with air quality in the farmhouse and obtained results that are not related to the respiratory health of farmers with air quality in the room, where P>0.05 and there is one house that has good quality. high physical conditions such as humid temperatures and high chemical quality of the air due to storing tools and plowing fields at home with a fairly high number of bacteria and fungi.

Assessment of Microbial Load in Regional Hospitals in Albania

Background Contaminated hospital indoor environments can expose patients to microorganisms and different infections. The aimed study was to assess the microbial load in hospital facilities inside Albania Regional Hospitals during the period 2017-2019. Methods A cross-sectional study was conducted during the period 2017-2019 for the assessment of microbial contamination in operating rooms, resuscitation, and delivery rooms in 12 regional hospitals in Albania. One thousand and three hundred microbiological specimens were collected from air and surfaces using 5% sheep blood agar (Oxoid, UK) and processed at IPH microbiology laboratory following the standard bacteriological procedures Data were analyzed using Statistical Software Package for Social Sciences (SPSS) version 23. Results Out of the total number of samples, 1148 (88.3%) were collected from surfaces and 152 (11.7%) were from the air. Bacterial growth was identified in 314 (24.2%) out of 1300 samples (95% CI 21.89–26.62). From the total site samples processed during the study period, bacterial growth showed 282 (89.8%) samples from surfaces and 32 (10.2%) air samples. There was found a significant association p-value =0.035. Regarding the sampling place collection, the largest number were collected in operating rooms (60.3%) followed by emergency rooms (28.2%), ICUs (7.7%), and maternity units (3.8%). Gram-negative isolates were predominant at 235 (74.8%), while the Gram-positive were at 60 (19.1%). E. coli was the most frequent bacterial isolate (50%) followed by Pseudomonas aeruginosa (23.6%), Staphylococcus aureus (19.1%), and Klebsiella pneumoniae (1.3%). Also, we found a fungal agent such as Aspergillus in 19 (6.1%) samples. The isolated bacteria's overall drug resistance profile revealed that 66.8% of gram-positive bacteria were resistant to two or more antimicrobial drugs tested. Conclusion This study revealed that the surface and air and air within different wards of the hospitals studied were contaminated with different types of bacteria. Bacterial loads on the surface and air exceeded normal limits. Additionally, the study pointed out high levels of antimicrobial resistance to the drugs commonly prescribed for isolates. Therefore, intervention strategies need to be strengthened to expand infection prevention practices in hospitals. Continuous monitoring and monitoring of in-hospital pathogen types and susceptibility patterns should be performed on a very regular basis.

Indoor Air Quality in Elderly Centers: Pollutants Emission and Health Effects

The world population is ageing, in particular in the developed world, with a significant increase in the percentage of people above 60 years old. They represent a segment of the population that is more vulnerable to adverse environmental conditions. Among them, indoor air quality is one of the most relevant, as elders spend comparatively more time indoors than younger generations. Furthermore, the recent COVID-19 pandemic contributed immensely to raising awareness of the importance of breathing air quality for human health and of the fact that indoor air is a vector for airborne infections and poisoning. Hence, this work reviews the state of the art regarding indoor air quality in elderly centers, considering the type of pollutants involved, their emission sources, and their health effects. Moreover, the influence of ventilation on air quality is also addressed. Notwithstanding the potential health problems with the corresponding costs and morbidity effects, only a few studies have considered explicitly indoor air quality and its impacts on elderly health. More studies are, therefore, necessary to objectively identify what are the impacts on the health of elderly people due to the quality of indoor air and how it can be improved, either by reducing the pollutants emission sources or by more adequate ventilation and thermal comfort strategies.

ITS1 amplicon sequencing of feline gut mycobiome of Malaysian local breeds using Nanopore Flongle

The gut mycobiome exhibits major influence on the gastrointestinal health and disease but received less attention due to low abundance. This study characterizes the fungal community and compares the microbial diversity between indoor and outdoor cats. Genomic DNA was extracted and sequenced by targeting the Internal Transcribed Spacer 1 (ITS1) region using Flongle flow cell on MinION™ sequencing platform. Results show the phylum Ascomycota and genus Peniophorella were numerous in indoor cats, whereas the Basidiomycota and Pichia were abundant in outdoor cats. Peniophorella formed the core mycobiome in both feline populations. Furthermore, alpha (p value = 0.0207) and beta diversities (p value = 0.009) results showed significant differences between the two groups. Overall, indoor cats have greater amounts of Peniophorella, whereas outdoor cats have higher Trichosporon and unclassified Sordariaceae. The study also suggests that keeping a cat indoors or left as a stray will affect their respective gut mycobiome.

Aerosolization of fungal spores in indoor environments

Fungi in indoor environments can cause adverse health effects through inhalation and epidermal exposure. The risk of fungal exposure originates from the aerosolization of fungal spores. However, spore aerosolization is still not well understood. This paper provides a review of indoor fungal contamination, especially the aerosolization of fungal spores. We attempted to summarize what is known today and to identify what more information is needed to predict the aerosolization of fungal spores. This paper first reviews fungal contamination in indoor environments and HVAC systems. The detachment of fungal spores from colonies and the spore aerosolization principle are then summarized. Based on the above discussion, prediction methods for spore aerosolization are discussed. This review further clarifies the current situation and future efforts required to accurately predict spore aerosolization. This information is useful for forecasting and controlling the aerosolization of fungal spores.

Comprehensive health risk assessment of microbial indoor air quality in microenvironments

The higher airborne microbial concentration in indoor areas might be responsible for the adverse indoor air quality, which relates well with poor respiratory and general health effects in the form of Sick building syndromes. The current study aimed to isolate and characterize the seasonal (winter and spring) levels of culturable bio-aerosols from indoor air, implicating human health by using an epidemiological health survey. Microorganisms were identified by standard macro and microbiological methods, followed by biochemical testing and molecular techniques. Sampling results revealed the bacterial and fungal aerosol concentrations ranging between (300–3650 CFU/m³) and (300–4150 CFU/m³) respectively, in different microenvironments during the winter season (December-February). However, in spring (March-May), bacterial and fungal aerosol concentrations were monitored, ranging between (450–5150 CFU/m³) and (350–5070 CFU/m³) respectively. Interestingly, Aspergillus and Cladosporium were the majorly recorded fungi whereas, Staphylococcus, Streptobacillus, and Micrococcus found predominant bacterial genera among all the sites. Taken together, the elevated levels of bioaerosols are the foremost risk factor that can lead to various respiratory and general health issues in additional analysis, the questionnaire survey indicated the headache (28%) and allergy (20%) were significant indoor health concerns. This type of approach will serve as a foundation for assisting residents in taking preventative measures to avoid exposure to dangerous bioaerosols.

Storm of a rare opportunistic life threatening mucormycosis among post COVID-19 patients: A tale of two pathogens

Mucormycosis is a rare but life-threatening opportunistic fungal infection caused by a group of molds that belong to Zygomycetes of the order Mucorales. These fungi are found in the environment such as soil, decaying vegetation, and organic matters. Sporangiospores present in the environment enter the human body through inhalation or direct skin inoculation by trauma or ingestion and result in pulmonary, cutaneous, and gastrointestinal mucormycosis, respectively, in immunocompromised hosts. Patients with uncontrolled diabetes, hematological malignancies, high-dose glucocorticoid therapy, iron overload, and organ transplantation are at high risk of acquiring mucormycosis. The second wave of severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] affected India severely with the highest number of cases and deaths compared to all other countries. Additionally, the country was affected by emergence of rare but life-threatening mucormycosis. Currently, many coronavirus disease 2019 patients with underlying risk factors such as uncontrolled diabetes, high-dose steroid therapy, and exposure to mechanical ventilation have developed mucormycosis. Inhalation is the most common mode of transmission that results in colonization of sporangiospores in the nose. In immunocompromised host, sporangiospores germinate, and subsequently form hyphae. These hyphae invade into tissues, and produce tissue infarction, necrosis, and thrombosis. Angioinvasion causes hematogenous dissemination to many organs, predominantly to brain, that result in rhino-orbital-cerebral mucormycosis. Clinical characteristics, radio imaging, fungal culture, histopathology, and molecular techniques are the key diagnostic methods. Surgical intervention and aggressive antifungal therapy are the main management strategies. Amphotericin B is the drug of choice for treatment of mucormycosis, whereas posaconazole or isavuconazole is used for step-down therapy and salvage therapy.

Systematic study on the relationship between particulate matter and microbial counts in hospital operating rooms

In this study, a systematic procedure for establishing the relationship between particulate matter (PM) and microbial counts in four operating rooms (ORs) was developed. The ORs are located in a private hospital on the western coast of Peninsular Malaysia. The objective of developing the systematic procedure is to ensure that the correlation between the PMs and microbial counts are valid. Each of the procedures is conducted based on the ISO, IEST, and NEBB standards. The procedures involved verifying the operating parameters are air change rate, room differential pressure, relative humidity, and air temperature. Upon verifying that the OR parameters are in the recommended operating range, the measurements of the PMs and sampling of the microbes were conducted. The TSI 9510-02 particle counter was used to measure three different sizes of PMs: PM 0.5, PM 5, and PM 10. The MAS-100ECO air sampler was used to quantify the microbial counts. The present study confirms that PM 0.5 does not have an apparent positive correlation with the microbial count. However, the evident correlation of 7% and 15% were identified for both PM 5 and PM 10, respectively. Therefore, it is suggested that frequent monitoring of both PM 5 and PM 10 should be practised in an OR before each surgical procedure. This correlation approach could provide an instantaneous estimation of the microbial counts present in the OR.

Awareness Toward Mucormycosis Attack for COVID Patients

Risk groups for mucormycosis include persons with immunosuppressed immune system and uncontrolled diabetes. The patients suffering from corona virus or post covid patients have been found to be entrapped with this fungal infection due to suppression in the immune system. Also the major attack was reported in those patients who were in Intensive Care units. It arises due to the fungal infection of various species and can occur simultaneously with covid. The development of black fungus mostly affects lungs, eyes, brain, and skin and is not at all contagious. Proper diagnostic can only predict that the patient is in invasive attack of which mucor species. It is better to take prevention by wearing medicated masks, hand gloves, wearing glasses, avoid dusty and damp places.

Development of an indoor air purification system to improve ventilation and air quality

Novel types of an air purification system for improving indoor air quality (IAQ) and ventilation by reducing carbon dioxide (CO₂) concentration were assessed in office buildings in India. This study provides an evaluation of a control system that reduces toxic gases in indoor spaces using the synthesized filter media. The reduction potential of CO₂ levels of the control system, for different air handling unit (AHU) capacities, were compared. Experimental studies and in-situ evaluation has been done using the air purification system. Ventilation rates and CO₂ concentration are monitored before and after the installation of the purification system. The results of the investigation indicated CO₂ concentrations were reduced by more than 40% with the purification system. Fresh air intake to maintain the desired ventilation rates has been reduced to more than 50%, further reduce heat load. Ventilation flow rates were achieved with this air purification system. This system has the potential aspiration in controlling the CO₂ levels in mechanically ventilated buildings. CO₂ concentrations were brought down to permissible limits and maintained further without introducing fresh air into the system. Based on the results, assessment of the air purification system is a crucial and wide range of applicability in indoor environments to reduce cooling costs.

Elemental and microbiota content in indoor and outdoor air using recuperation unit filters

This paper presents the results of a twelve-month measurement campaign conducted at a rural single-family house in Poland. The external and internal filters of a recuperator used to mechanically ventilate the building were used to separate the total suspended particles (TSPs), and the concentrations of fifteen elements and abundance of fungi and bacteria were determined. Lower annual mean concentrations were observed indoors, and the concentrations of most elements did not significantly change between seasons. There were some differences between winter and summer, which may have resulted from changes in the ventilation regimes in the house. The number of bacteria was similar outdoors and indoors, while the amounts of fungi were higher indoors (p < 0.05). The order of metal concentrations outdoors agreed well with observations in other countries, while indoors the metal concentrations order indicated the individual characteristics of the building. The species diversity of fungi was higher than that of bacteria, and different species were found indoors and outdoors, while bacteria were typically present both indoors and outdoors. Different TSP sources were identified indoors and outdoors, suggesting limited penetration between the two environments. However, both environments were affected by traffic. Mechanical ventilation systems with built-in filters (such as recuperators) were useful in assessing the air quality within the building, and the changeable recuperation filters offer an approach to assess the air quality in several houses without any additional cost or discomfort to the residents.

An assessment of the air quality in apple warehouses: new records of Aspergillus europaeus, Aspergillus pulverulentus, Penicillium allii and Penicillium sumatraense as decay agents

Airborne fungi are one of the major components of aeromycobiota known to produce several fungal diseases in fruits. Their presence in indoor environment of warehouses may limit the storage period of apples. Qualitative and quantitative analyses of airborne fungal spores were conducted using gravity settling techniques to detect fungal airspora present in the atmosphere of two apple warehouses in Tunisia. In this study, 375 fungal isolates were obtained and purified. Phylogenetic analysis of calmodulin, beta-tubulin and ITS regions coupled with phenotypic characterization helped to identify 15 fungal species. Penicillium exhibited the highest diversity with ten species detected (Penicillium allii, P. chrysogenum, P. citrinum, P. expansum, P. italicum, P. polonicum, P. solitum, P. steckii, P. sumatraense and P. viridicatum), followed by four species of Aspergillus genus (Aspergillus europaeus, A. flavus, A. niger and A. pulverulentus) and Alternaria alternata. In vivo experiments confirmed the pathogenicity of 13 species at room temperature and under cold-storage conditions. Among them, A. europaeus, A. pulverulentus, P. allii and P. sumatraense were described for the first time as pathogens on apples. The present study identified the major airborne fungi associated with postharvest rot in apple storage facilities in Tunisia and may help in efficient control of postharvest and storage fruit diseases.

Contribution of Visible Surface Mold to Airborne Fungal Concentration as Assessed by Digital Image Quantification

The rapid monitoring of total fungi, including air and surface fungal profiling, is an important issue. Here, we applied air and surface sampling, combined with digital image quantification of surface mold spots, to evaluate the contribution of surface fungi to airborne fungal concentrations. Cladosporium, Penicillium, Aspergillus, and yeast often appeared in the air or on wall surfaces during sampling. The indoor/outdoor concentration ratios (I/O ratios) demonstrated that the airborne concentrations of commonly found fungal genera outdoors were higher than those indoors (median I/O ratio = 0.65–0.91), excluding those of Penicillium and yeast. Additionally, the surface density (fungal concentration/area) of individual fungi showed no significant correlation with the airborne concentration, excluding that of Geotrichum. However, if a higher surface ratio (>0.00031) of mold spots appeared in the total area of an indoor environment, then the concentrations of Aspergillus and Geotrichum in the air increased significantly. Our results demonstrated that the airborne concentration of indoor fungi is significantly correlated with the outdoor concentration. A higher density of surface fungi does not necessarily contribute to a high fungal concentration in the air. In contrast to fungal density, quantification of the surface fungal area is recommended to assess the risk of surface fungi propelling into the air.

Influence of TiO2 Nanoparticles on the Resistance of Cementitious Composite Materials to the Action of Fungal Species

The development of mold films on the cement surfaces of buildings is a health and safety problem for the population, aesthetic but also in terms of their durability. The use of specific performance of cementitious composites containing TiO₂ nanoparticles, photoactivated by UV radiation, can be a viable solution to mitigate to eliminate these problems. The experimental studies presented aim to analyze the capacity to inhibit the development of mold type Aspergillus and Penicillium on the surface of composite materials with nano-TiO₂ content and the identification of the optimal range of nanomaterial addition. The identification and analysis of the inhibition halo (zone with a biological load of maximum 1–10 colonies of microorganisms) confirmed the biocidal capacity of the cementitious composites, but also indicated the possibility that an excess of TiO₂ nanoparticles in the mixture could induce a development of cell resistance, which would be unfavorable both in terms of behavior and in terms of cost.

Seasonal variation and size distribution in the airborne indoor microbial concentration of residential houses in Delhi and its impact on health

Exposure of microbial agents in the air of indoor dwellings is associated with effects on respiratory and general health. The current study was conducted in the urban area of Delhi Metropolis for the seasonal quantitative assessment of viable microbial indoor air quality. Bioaerosol measurement was conducted by using Anderson six stage impactor with cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1, and 0.65 µm) throughout the all the seasons (April 2019 to March 2020). Meteorological parameters such as temperature and relative humidity were measured to check their effect on microbial survival. Air quality index data of the sampling area were recorded by DPCC air quality monitoring system, Ashok Vihar, Delhi. The highest (1654 ± 876.87 CFU/m3) and lowest (738 ± 443.59 CFU/m3) mean bacterial concentration in houses was recorded in August and December, respectively. Similarly, the highest fungal concentration (1275 ± 645.22 CFU/m3) was found in August and the lowest in (776 ± 462.46 CFU/m3) in January. Bacterial respirable fraction shows an irregular pattern in different seasons. In the case of fungi, the respirable fraction of 2.1 and 1.1 contributes more than 60% of total culturable bioaerosols in all seasons. Bacterial genera including Staphylococcus, Micrococcus, and Streptobacillus were most dominant, and Cladosporium, Aspergillus, Penicillium, and Alternaria were the most dominant fungal genera observed indoors. The results of this study suggest that higher respirable fungal fraction might penetrate deeper into the lungs and cause various health effects. A higher concentration of bioaerosols in outdoor areas than indoor shows that the source of indoor bioaerosols is outdoor air.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10453-021-09718-3.

Influence of TiO2 Nanoparticles on the Resistance of Cementitious Composite Materials to the Action of Bacteria

The formation of biofilms on cementitious building surfaces can cause visible discoloration and premature deterioration, and it can also represent a potential health threat to building occupants. The use of embedded biofilm-resistant photoactivated TiO₂ nanoparticles at low concentrations in the cementitious composite matrix is an effective method to increase material durability and reduce maintenance costs. Zone of inhibition studies of TiO₂-infused cementitious samples showed efficacy toward both Gram-negative and Gram-positive bacteria.

Microbiological analysis of bacterial and fungal bioaerosols from burn hospital of Yazd (Iran) in 2019

INTRODUCTION

Bioaerosols play an important role in incidence of infections in indoor and outdoor air of hospitals. Microorganisms play a critical role in the health of human beings and they are found everywhere in the environment, including different wards of a hospital. So, quantitative and qualitative analysis of microorganisms is highly important in hospital air. The aim of this study was to evaluate the diversity and density of bacteria and fungi in the air of Shohadaye Mehrab Hospital in Yazd City, Iran.

MATERIALS AND METHODS

Sampling was performed using a single-stage pump (Quick Take30) at a flow rate of 28.3 l per minute for five minutes. As a result, 288 indoor and outdoor hospital air samples were collected. Numbers and types of bacterial and fungal colonies were identified using colony morphology, gram staining, and standard microbial tests. Chi-square test, PCA and linear mixed model were run by SPSS version 24.0 for data analysis.

RESULTS

The highest bacterial contaminations were found in the burns ward (294 CFU/m³), operating theater (147 CFU/m³), and emergency department (124 CFU/m³), respectively. Fungal contamination was higher in the derm ward (110 CFU/m³) than other sampling sites. The dominant genus of gram-positive bacteria was Staphylococcus epidermidis (n = 60, 62.5%) and the dominant genus of gram-negative bacteria was Citrobacter freundi (n = 11, 11.5%). The most fungal gens isolated from the hospital air samples were Penicillium (n = 73, 76%), Alternaria (n = 51, 53.1%), Aspergillus niger (n = 40, 41.7%), and Aspergillus flavus (n = 34, 35.4%), respectively.

CONCLUSION

Considering that the burn wounds represent a susceptible site for opportunistic microorganisms, even low concentration of fungi/bacteria in air can be considered as a risk factor that facilitates transmission of the infectious agents in the hospital. Therefore, control measures should be taken to reduce the infection hazard in health staff and patients. These measures include ensuring effective ventilation, cleaning and decontaminating surfaces and equipment, restricting the personnel and patient companions' movement across the wards.

Application of Nanotechnology in Wood-Based Products Industry: A Review

Wood-based industry is one of the main drivers of economic growth in Malaysia. Forest being the source of various lignocellulosic materials has many untapped potentials that could be exploited to produce sustainable and biodegradable nanosized material that possesses very interesting features for use in wood-based industry itself or across many different application fields. Wood-based products sector could also utilise various readily available nanomaterials to enhance the performance of existing products or to create new value added products from the forest. This review highlights recent developments in nanotechnology application in the wood-based products industry.

Air pollution and its impact on the concentration of airborne fungi in the megacity of São Paulo, Brazil

In the context of megacities in an urban environment, air quality is an important issue, due to the direct correlation to population's health. The biomonitoring of pollutants can indicate subtle environmental alterations, for that, anemophilous fungi can be monitored for changes in atmospheric conditions related to pollution. In the present study, the concentration of fungi and bacteria in the atmosphere was measured during a specific vehicle fleet reduction in the city of São Paulo, Brazil, from May 24 to 30, 2018, using impactor air samplers. The number of isolated developed colonies was related to atmospheric conditions and the concentration of other air pollutants constantly monitored. Aspergillus, Curvularia, Penicillium, Neurospora, Rhizopus and Trichoderma were identified. The number of colony-forming units increased by approximately 80% during the sampling period in response to environmental changes favored by the fleet reduction. This result implies the relation between fuel emissions, concentration of atmospheric pollutants, and the presence of viable fungal spores in the urban environment, which highlights the importance of combined public policies for air quality in large cities.

Detection of Airborne Biological Particles in Indoor Air Using a Real-Time Advanced Morphological Parameter UV-LIF Spectrometer and Gradient Boosting Ensemble Decision Tree Classifiers

We present results from a study evaluating the utility of supervised machine learning to classify single particle ultraviolet laser-induced fluorescence (UV-LIF) signatures to investigate airborne primary biological aerosol particle (PBAP) concentrations in a busy, multifunctional building using a Multiparameter Bioaerosol Spectrometer. First we introduce and demonstrate a gradient boosting ensemble decision tree algorithm’s ability to accurately classify laboratory generated PBAP samples into broad taxonomic classes with a high level of accuracy. We then develop a framework to appraise the classification accuracy and performance using the Hellinger distance metric to compare product parameter probability density function similarity; this framework showed that key training classes were sufficiently different in terms of particle fluorescence and morphology to facilitate classification. We also demonstrate the utility of including advanced morphological parameters to minimise inter-class conflation and improve classification confidence, where relying on the fluorescent spectra alone would likely result in misattribution. Finally, we apply these methods to ambient data collected within a large multi-functional building where ambient bacterial- and fungal-like classes were identified to display trends corresponding to human activity; fungal-like classes displayed a consistent diurnal trend with a maximum at midday and hourly peaks correlating to movements within the building; bacteria-like aerosol displayed complex, episodic events during opening hours. All PBAP classes fell to low baseline concentrations when the building was unoccupied overnight and at weekends.

Advances in Methods for Recovery of Ferrous, Alumina, and Silica Nanoparticles from Fly Ash Waste

Fly ash or coal fly ash causes major global pollution in the form of solid waste and is classified as a “hazardous waste”, which is a by-product of thermal power plants produced during electricity production. Si, Al, Fe Ca, and Mg alone form more than 85% of the chemical compounds and glasses of most fly ashes. Fly ash has a chemical composition of 70–90%, as well as glasses of ferrous, alumina, silica, and CaO. Therefore, fly ash could act as a reliable and alternative source for ferrous, alumina, and silica. The ferrous fractions can be recovered by a simple magnetic separation method, while alumina and silica can be extracted by chemical or biological approaches. Alumina extraction is possible using both alkali- and acid-based methods, while silica is extracted by strong alkali, such as NaOH. Chemical extraction has a higher yield than the biological approaches, but the bio-based approaches are more environmentally friendly. Fly ash can also be used for the synthesis of zeolites by NaOH treatment of variable types, as fly ash is rich in alumino-silicates. The present review work deals with the recent advances in the field of the recovery and synthesis of ferrous, alumina, and silica micro and nanoparticles from fly ash.

Modeling microbial growth in carpet dust exposed to diurnal variations in relative humidity using the "Time-of-Wetness" framework

Resuspension of microbes in floor dust and subsequent inhalation by human occupants is an important source of human microbial exposure. Microbes in carpet dust grow at elevated levels of relative humidity, but rates of this growth are not well established, especially under changing conditions. The goal of this study was to model fungal growth in carpet dust based on indoor diurnal variations in relative humidity utilizing the time-of-wetness framework. A chamber study was conducted on carpet and dust collected from 19 homes in Ohio, USA and exposed to varying moisture conditions of 50%, 85%, and 100% relative humidity. Fungal growth followed the two activation regime model, while bacterial growth could not be evaluated using the framework. Collection site was a stronger driver of species composition (P = 0.001, R2  = 0.461) than moisture conditions (P = 0.001, R2  = 0.021). Maximum moisture condition was associated with species composition within some individual sites (P = 0.001-0.02, R2  = 0.1-0.33). Aspergillus, Penicillium, and Wallemia were common fungal genera found among samples at elevated moisture conditions. These findings can inform future studies of associations between dampness/mold in homes and health outcomes and allow for prediction of microbial growth in the indoor environment.

Metabolomic Analysis of Aspergillus niger Isolated From the International Space Station Reveals Enhanced Production Levels of the Antioxidant Pyranonigrin A

Secondary metabolite (SM) production in Aspergillus niger JSC-093350089, isolated from the International Space Station (ISS), is reported, along with a comparison to the experimentally established strain ATCC 1015. The analysis revealed enhanced production levels of naphtho-γ-pyrones and therapeutically relevant SMs, including bicoumanigrin A, aurasperones A and B, and the antioxidant pyranonigrin A. Genetic variants that may be responsible for increased SM production levels in JSC-093350089 were identified. These findings include INDELs within the predicted promoter region of flbA, which encodes a developmental regulator that modulates pyranonigrin A production via regulation of Fum21. The pyranonigrin A biosynthetic gene cluster was confirmed in A. niger, which revealed the involvement of a previously undescribed gene, pyrE, in its biosynthesis. UVC sensitivity assays enabled characterization of pyranonigrin A as a UV resistance agent in the ISS isolate.

Morphology and quantification of fungal growth in residential dust and carpets

Mold growth indoors is associated with negative human health effects, and this growth is limited by moisture availability. Dust deposited in carpet is an important source of human exposure due to potential elevated resuspension compared to hard floors. However, we need an improved understanding of fungal growth in dust and carpet to better estimate human exposure. The goal of this study was to compare fungal growth quantity and morphology in residential carpet under different environmental conditions, including equilibrium relative humidity (ERH) (50%, 85%, 90%, 95%, 100%), carpet fiber material (nylon, olefin, wool) and presence/absence of dust. We analyzed incubated carpet and dust samples from three Ohio homes for total fungal DNA, fungal allergen Alt a 1, and fungal morphology. Dust presence and elevated ERH (≥85%) were the most important variables that increased fungal growth. Elevated ERH increased mean fungal DNA concentration (P < 0.0001), for instance by approximately 1000 times at 100% compared to 50% ERH after two weeks. Microscopy also revealed more fungal growth at higher ERH. Fungal concentrations were up to 100 times higher in samples containing house dust compared to no dust. For fiber type, olefin had the least total fungal growth, and nylon had the most total fungi and A. alternata growth in unaltered dust. Increased ERH conditions were associated with increased Alt a 1 allergen concentration. The results of this study demonstrate that ERH, presence/absence of house dust, and carpet fiber type influence fungal growth and allergen production in residential carpet, which has implications for human exposure.

Indoor Culturable Fungal Load and Associated Factors among Public Primary School Classrooms in Gondar City, Northwest Ethiopia, 2018: A Cross-sectional Study

Background

Fungi are heavy threats to public health in indoor environments, particularly in residential buildings, offices, and schools where people spend a lot of time indoors. This study was conducted to investigate the load of culturable fungi and associated factors in a school indoor environment.

Methods

Institutional based cross-sectional study was conducted in eight public primary school classrooms in Gondar City from March to April 2018. Settle plate technique was used to determine the culturable fungal load. Log transformed linear regression analysis was employed. The beta-coefficient with a 95% confidence interval was used to determine the degree and direction of the association with a p-value less than 0.05.

Results

The highest and the lowest mean culturable fungal loads recorded were 1140.29 CFU/m³ and 211.25 CFU/m³, respectively. Aspergillus, Mucor, Penicillium, Candida, Microsporum, Trichophyton, Rhizopus, Alternaria and Fusarium species were isolated. Age of buildings (β= -0.122, 95%CI -0.238,-0.007), area of classroom (β= 0.639, 95% CI 0.285, 0.993), temperature (β= -0.189, 95% CI -0.325,-0.047), humidity (β= -0.023, 95% CI -0.043, -0.002) and PM10 (β= -0.01, 95% CI -0.015,-0.005) were associated with culturable fungal load.

Conclusions

High culturable fungal load was found in school classrooms in Gondar City. Age of buildings, area of classrooms, temperature, humidity, and PM10 were predictors of the culturable fungal load. Therefore, proficient corrective methods are needed to combat the problem of indoor air quality in a school indoor environment by controlling factors contributing to growth of fungi.

Gas-phase removal of indoor volatile organic compounds and airborne microorganisms over mono- and bimetal-modified (Pt, Cu, Ag) titanium(IV) oxide nanocomposites

The photocatalytic deactivation of volatile organic compounds and mold fungi using TiO₂ modified with mono- and bimetallic (Pt, Cu, Ag) particles is reported in this study. The mono- and bimetal-modified (Pt, Cu, Ag) titanium(IV) oxide photocatalysts were prepared by chemical reduction method and characterized using XRD, XPS, DR/UV-Vis, BET, and TEM analysis. The effect of incident light, type and content of mono- and bimetallic nanoparticles deposited on titanium(IV) oxide was studied. Photocatalytic activity of as-prepared nanocomposites was examined in the gas phase using LEDs array. High photocatalytic activity of Ag/Pt-TiO₂ and Cu/Pt-TiO₂ in the reaction of toluene degradation resulted from improved efficiency of interfacial charge transfer process, which was consistent with the fluorescence quenching effect revealed by photoluminescence (PL) emission spectra. The photocatalytic deactivation of Penicillium chrysogenum, a pathogenic fungi present in the indoor environment, especially in a damp or water-damaged building using mono- and bimetal-modified (Pt, Cu, Ag) titanium(IV) oxide was evaluated for the first time. TiO₂ modified with mono- and bimetallic NPs of Ag/Pt, Cu, and Ag deposited on TiO₂ exhibited improved fungicidal activity under LEDs illumination than pure TiO₂ .

Developement of health risk rating scale for indoor airborne fungal exposure

This paper aims to quantify airborne fungal load in air-conditioned rooms and develop a health risk rating scale for different indoor environments. Five sampling locations in Kolkata frequented by a heterogeneous human population, containing various types of fungal growth-promoting substances (FGPS) like old documents, food items, waste hair, etc. were chosen as sampling locations where an Andersen Two-Stage Cascade Impactor was ran using Rose Bengal agar and Potato Dextrose agar media plates. Total spore load (CFU/m³), species diversity, species dominance, human exposure time, susceptible age and FGPS were considered the risk factors for this study. A risk rating scale was developed after evaluating the relative importance of these different factors in relation to human health. The most dominant genera were Aspergillus, followed by Penicillium. Maximum CFU was observed at library, followed by computer room.

Environmental factors influencing fungal growth on gypsum boards and their structural biodeterioration: A university campus case study

The new era in the design of modern healthy buildings necessitates multidisciplinary research efforts that link principles of engineering and material sciences with those of building biology, in order to better comprehend and apply underlying interactions among design criteria. As part of this effort, there have been an array of studies in relation to the effects of building characteristics on indoor microbiota and their propensity to cause health issues. Despite the abundance of scientific inquiries, limited studies have been dedicated to concomitantly link these effects to the deterioration of 'structural integrity' in the building materials. This study focuses on the observed biodeteriorative capabilities of indoor fungi upon the ubiquitous gypsum board material as a function of building age and room functionality within a university campus. We observed that the fungal growth significantly affected the physical (weight loss) and mechanical (tensile strength) properties of moisture-exposed gypsum board samples; in some cases, tensile strength and weight decreased by more than 80%. Such intertwined associations between the biodeterioration of building material properties due to viable indoor fungi, and as a function of building characteristics, would suggest a critical need towards multi-criteria design and optimization of next-generation healthy buildings. Next to structural integrity measures, with a better understanding of what factors and environmental conditions trigger fungal growth in built environment materials, we can also optimize the design of indoor living spaces, cleaning strategies, as well as emergency management measures during probable events such as flooding or water damage.

The effect of temperature on airborne filamentous fungi in the indoor and outdoor space of a hospital

Fungi are one of the bioaerosols in indoor air of hospitals. They have adverse effects on staff and patients. The aim of this study was to investigate the effects of three incubation temperature on the density and composition of airborne fungi in an indoor and outdoor space of hospital. Sabouraud dextrose agar was used for culture the fungi. For improvement of aseptic properties, chloramphenicol was added to this medium. The density of airborne fungi was less than 282 CFU/m³. The highest density was detected in emergency room and the lowest of them was in neonatal intensive care unit (NICU) and operation room (OR). Results showed that fungi levels at 25 °C were higher than 37 and 15 °C (p = 0.006). In addition, ten different genera of fungi were identified in all departments. The predominant fungi were Fusarium spp., Penicillium spp., Paecilomyces spp., and Aspergillus niger. Moreover, the density and trend of distribution of Fusaruim spp. in the indoor space was directivity to outdoor space by ventilation system. The present study has provided that incubation temperature had effect on airborne fungi remarkably. We are suggested that more studies would be conducted on incubation temperature and other ambient factors on airborne fungi.

Environmental characteristics and taxonomy of microscopic fungi isolated from washing machines

Washing machines (WMs) are convenient places for fungal colonization. This study is focused on fungal diversity of WMs, and investigates relationships between habits of WM users and colonising species. Housekeeping conditions and habits were assessed in Hungary with a questionnaire. Several fungal species were identified by microscopy and sequence analysis of diagnostic loci. Based on the results, 32 % of the sampled WMs were highly polluted with various species of fungi. Forty six percent of them were colonised also by opportunistically human pathogenic species. In total, 32 yeast and 39 filamentous fungal strains were isolated. Growth tests were conducted with five selected taxa (Cutaneotrichosporon dermatis, Cystobasidium slooffiae, Meyerozyma guilliermondii, Candida parapsilosis and the Fusarium oxysporum species complex (FOSC)) to ascertain their tolerance ranges. None of the examined isolates were able to grow >50 °C, 4.10 < pH < 10.88. FOSC could grow at high salinity. More species were detected in WMs operated in rooms without heating systems (p = 0.0025). The number of species was higher in WMs located in the kitchen than the ones kept in bathroom or in other rooms (p = 0.0205). WMs may serve as a reservoir of pathogenic fungi, the presence of which may depend on the usage of these devices.

Diversity and abundance of airborne fungal spores in a rural cold dry desert environment in Argentinean Patagonia

This work describes a longitudinal study of three consecutive years carried out in the air of agricultural environments located in Northern Patagonia with cold dry desert climate (Köppen: Bwk). This study area comprises a rural valley with unique geographical and climatological conditions. Therefore, the aim of this work is to quantify and determine its fungal diversity, so this knowledge will contribute to detect potential pathogenic and toxic fungi that has been adapted to this type of environment and may overcome the incipient climate change. Samplings were conducted in two geographical zones of the study area and a microflow air sampler was used to isolate fungal taxa. The annual mean fungal counts were found in the order of E+03 CFU/m³ of air. The aerial mycoflora revealed a wide biodiversity of at least 28 genera and 50 fungal species. Cladosporium was the most abundant genus (76.97%), followed by Alternaria (12.48%), Epicoccum (4.41%) and Botrytis (1.81%). The rest of the genera were found in relative densities lower than 1%. In terms of species, C. cladosporioides (34.82%), C. limoniforme (21.72%), A. tenuissima (10.94%) and C. asperulatum predominated (9.01%). This is the first report of the air mycoflora of rural environments with cold dry desert climate which provides useful information to take preventive measures to avoid biological damage.

Fungal aerosols at dairy farms using molecular and culture techniques

Occupational exposure to harmful bioaerosols in industrial environments is a real threat to the workers. In particular, dairy-farm workers are exposed to high levels of fungal bioaerosols on a daily basis. Associating bioaerosol exposure and health problems is challenging and adequate exposure monitoring is a top priority for aerosol scientists. Using only culture-based tools does not express the overall microbial diversity and underestimate the large spectrum of microbes in bioaerosols and therefore the extended fungal profile that farmers are exposed to. The aim of this study was to provide an in-depth characterization of fungal exposure at Eastern Canadian dairy farms using qPCR and high-throughput sequencing methods. Specific primers were used for the quantification of Penicillium/Aspergillus and Aspergillus fumigatus in dairy farms air samples. Illumina Miseq sequencing of the ITS1 region provided sequences for the diversity analyses. The minimum and maximum concentration of Penicillium/Aspergillus ranged from 4.6 × 10⁶ to 9.4 × 10⁶ gene copies/m³ and from 1 × 10⁴ gene copies/m³ to 4.8 × 10⁵ gene copies/m³ for Aspergillus fumigatus, respectively. Differences in the diversity profiles of the five dairy farms support the idea that the novel approach identifies a large number of fungal taxa. The most striking differences include Microascus, Piptoporus, Parastagonospora, Dissoconium, Microdochium, Tubilicrinis, Ganoderma, Ustilago, Phlebia and Wickerhamomyces. The presence of a diverse portrait of fungi in air may represent a health risk for workers who are exposed on a daily basis. The broad spectrum of fungi detected in this study includes many known pathogens like Aspergillus, Acremonium, Alternaria and Fusarium. Adequate monitoring of bioaerosol exposure is necessary to evaluate and minimize risks.