Clinically relevant fungi in water and on surfaces in an indoor swimming pool facility

[Medical clinical diagnostics for indoor mould exposure - Update 2023 (AWMF Register No. 161/001)]

This article is an abridged version of the updated AWMF mould guideline "Medical clinical diagnostics in case of indoor mould exposure - Update 2023", presented in July 2023 by the German Society of Hygiene, Environmental Medicine and Preventive Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin, GHUP), in collaboration with German and Austrian scientific medical societies, and experts. Indoor mould growth is a potential health risk, even if a quantitative and/or causal relationship between the occurrence of individual mould species and health problems has yet to be established. There is no evidence for a causal relationship between moisture/mould damage and human diseases, mainly because of the ubiquitous presence of fungi and hitherto inadequate diagnostic methods. Sufficient evidence for an association between moisture/mould damage and the following health effects has been established for: allergic respiratory diseases, allergic rhinitis, allergic rhino-conjunctivitis, allergic bronchopulmonary aspergillosis (ABPA), other allergic bronchopulmonary mycosis (ABPM), aspergilloma, Aspergillus bronchitis, asthma (manifestation, progression, exacerbation), bronchitis (acute, chronic), community-acquired Aspergillus pneumonia, hypersensitivity pneumonitis (HP; extrinsic allergic alveolitis (EEA)), invasive Aspergillosis, mycoses, organic dust toxic syndrome (ODTS) [workplace exposure], promotion of respiratory infections, pulmonary aspergillosis (subacute, chronic), and rhinosinusitis (acute, chronically invasive, or granulomatous, allergic). In this context the sensitizing potential of moulds is obviously low compared to other environmental allergens. Recent studies show a comparatively low sensitization prevalence of 3-22,5 % in the general population across Europe. Limited or suspected evidence for an association exist with respect to atopic eczema (atopic dermatitis, neurodermatitis; manifestation), chronic obstructive pulmonary disease (COPD), mood disorders, mucous membrane irritation (MMI), odor effects, and sarcoidosis. (iv) Inadequate or insufficient evidence for an association exist for acute idiopathic pulmonary hemorrhage in infants, airborne transmitted mycotoxicosis, arthritis, autoimmune diseases, cancer, chronic fatigue syndrome (CFS), endocrinopathies, gastrointestinal effects, multiple chemical sensitivity (MCS), multiple sclerosis, neuropsychological effects, neurotoxic effects, renal effects, reproductive disorders, rheumatism, sick building syndrome (SBS), sudden infant death syndrome, teratogenicity, thyroid diseases, and urticaria.The risk of infection posed by moulds regularly occurring indoors is low for healthy persons; most species are in risk group 1 and a few in risk group 2 (Aspergillus fumigatus, A. flavus) of the German Biological Agents Act (Biostoffverordnung). Only moulds that are potentially able to form toxins can be triggers of toxic reactions. Whether or not toxin formation occurs in individual cases is determined by environmental and growth conditions, water activity, temperature and above all the growth substrates.In case of indoor moisture/mould damage, everyone can be affected by odor effects and/or mood disorders.However, this is not an acute health hazard. Predisposing factors for odor effects can include genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for mood disorders may include environmental concerns, anxiety, condition, and attribution, as well as various diseases. Risk groups to be protected particularly regarding infection risk are immunocompromised persons according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch-Institute (RKI), persons suffering from severe influenza, persons suffering from severe COVID-19, and persons with cystic fibrosis (mucoviscidosis); with regard to allergic risk, persons with cystic fibrosis (mucoviscidosis) and patients with bronchial asthma must be protected. The rational diagnostics include the medical history, physical examination, and conventional allergy diagnostics including provocation tests if necessary; sometimes cellular test systems are indicated. In the case of mould infections, the reader is referred to the specific guidelines. Regarding mycotoxins, there are currently no useful and validated test procedures for clinical diagnostics. From a preventive medical point of view, it is important that indoor mould infestation in relevant magnitudes cannot be tolerated for precautionary reasons.For evaluation of mould damage in the indoor environment and appropriate remedial procedures, the reader is referred to the mould guideline issued by the German Federal Environment Agency (Umweltbundesamt, UBA).

Assessment of Portuguese fitness centers: Bridging the knowledge gap on harmful microbial contamination with focus on fungi

The lack of knowledge regarding the extent of microbial contamination in Portuguese fitness centers (FC) puts attendees and athletes at risk for bioaerosol exposure. This study intends to characterize microbial contamination in Portuguese FC by passive sampling methods: electrostatic dust collectors (EDC) (N = 39), settled dust (N = 8), vacuum filters (N = 8), and used cleaning mops (N = 12). The obtained extracts were plated in selective culture media for fungi and bacteria. Filters, EDC, and mop samples' extracts were also screened for antifungal resistance and used for the molecular detection of the selected Aspergillus sections. The detection of mycotoxins was conducted using a high-performance liquid chromatograph (HPLC) system and to determine the cytotoxicity of microbial contaminants recovered by passive sampling, HepG2 (human liver carcinoma) and A549 (human alveolar epithelial) cells were employed. The results reinforce the use of passive sampling methods to identify the most critical areas and identify environmental factors that influence microbial contamination, namely having a swimming pool. The cardio fitness area presented the highest median value of total bacteria (TSA: 9.69 × 102 CFU m-2.day-1) and Gram-negative bacteria (VRBA: 1.23 CFU m-2.day-1), while for fungi it was the open space area, with 1.86 × 101 CFU m-2.day-1. Aspergillus sp. was present in EDC and in filters used to collect settled dust. Reduced azole susceptibility was observed in filters and EDC (on ICZ and VCZ), and in mops (on ICZ). Fumonisin B2 was the only mycotoxin detected and it was present in all sampling matrixes except settled dust. High and moderate cytotoxicity was obtained, suggesting that A549 cells were more sensitive to samples' contaminants. The observed widespread of critical toxigenic fungal species with clinical relevance, such as Aspergillus section Fumigati, as well as Fumonisin B2 emphasizes the importance of frequent and effective cleaning procedures while using shared mops appeared as a vehicle of cross-contamination.

Waterborne disease outbreaks in treated recreational water facilities: a Socio-Ecological Model perspective

Treated recreational water facilities, including swimming pools and water play parks, have often been implicated in infectious disease outbreaks. Addressing this problem is complex due to the multiple and interrelated factors contributing to outbreaks in these settings. These factors may relate to inappropriate behaviours of users and operators, lack of and inconsistent regulation of these facilities, insufficient facility maintenance, and problems associated with the design of these facilities. Given the complexity of this issue, we argue that the Socio-Ecological Model (SEM) provides a useful framework to help identify the multi-level influences and factors that have implications for designing interventions to prevent this public health problem, whilst assisting in guiding future research in this area. We apply the SEM to the current literature to help identify the influences and factors contributing to infectious disease outbreaks in treated recreational water facilities to support this argument. We also identify several gaps in the existing research that would benefit from further examination to help prevent infectious disease outbreaks in treated recreational water facilities such as public swimming pools and water play parks.

Characterization and phylogeny of fungi isolated from industrial wastewater using multiple genes

The aim of this study was the isolation and molecular characterization of fungi from untreated refinery effluent by using multiple conserved genes. The Fungi isolated were characterized based on PCR amplification and genomic sequencing of the internal transcribed spacer region (ITS), partial β-tubulin (BenA), calmodulin (CaM), and RNA polymerase second large subunit (RPB2) genes, along with morphological characterization. The obtained sequences were subjected to BLAST analysis and the corresponding fungal isolates were assigned species names after comparison with representative sequences available in GenBank. Fifteen (15) Fungi species belonging to four genera of Aspergillus, Penicillium, Fusarium, and Trichoderma with Aspergillus as the predominant genus were identified. Therefore these genes should be used as molecular markers for species level identification of fungi (especially Aspergillus and Penicillium as proven in this study.

The occurrence of potentially pathogenic filamentous fungi in recreational surface water as a public health risk

Microfungi occurring in surface water may represent an important health risk. Recreational water reservoirs are a potential reservoir of pathogenic fungi. The aim of the study was to assess the diversity of mycobiota in selected artificial bathing reservoirs with regard to its biosafety for the human population. The studies were conducted during the summer of 2016 in three research seasons (June (I), July and August (II), and September (III)), taking into account the various periods of recreational activities. Filamentous fungi were isolated from water samples collected at five different ponds utilized for recreation. From 162 water samples, 149 fungal taxa of filamentous fungi were identified: 140 were classified to species level and only nine to genus level. Aspergillus fumigatus was the dominant species. The highest species richness (S) was noted in June, with 93 fungal taxa (Menhinick's index from 2.65 to 4.49). Additionally, in season I, the highest diversity of fungal species was revealed (Simpson's diversity index from 0.83 to 0.99). The average number of CFU/1 mL sample ranged between 0.4 and 4.6 depending on the time of sampling and ponds. Of all the isolated species, 128 were clinically relevant (11 from RG-2 and 117 from RG-1), highlighting the need to introduce seasonal mycological monitoring of such reservoirs.

Diversity, Co-occurrence and Implications of Fungal Communities in Wastewater Treatment Plants

Three wastewater treatment plants (WWTPs) located in Gauteng province in South Africa were investigated to determine the diversity, co-occurrence and implications of their fungal communities using illumina sequencing platform and network analysis. Phylogenetic taxonomy revealed that members of the fungal communities were assigned to 6 phyla and 361 genera. Basidiomycota and Ascomycota were the most abundant phyla, dominated by the genera Naumovozyma, Pseudotomentella, Derxomyces, Ophiocordyceps, Pulchromyces and Paecilomyces. Phylogenetic analysis revealed the existence of fungal OTUs related to class lineages such as Agaricomycetes, Eurotiomycetes and Sordariomycetes indicating new fungal diversity in WWTPs. Dominant and rare fungal genera that can potentially be used in bioremediation such as Trichoderma, Acremonium, Talaromyces, Paecilomyces, cladophialophora and Saccharomyces were detected. Conversely, genera whose members are known to be pathogenic to human and plant such as Olpidium, Paecilomyces, Aspergillus, Rhodotorula, Penicillium, Candida, Synchytrium, Phyllosticta and Mucor were also detected in all WWTPs. Phylotype analysis confirmed that some fungal phylotypes were highly similar to the reported fungal pathogens of concern. Co-occurrence network analysis revealed that the fungal genera such as Minimedusa, Glomus, Circinella, Coltricia, Caloplaca, Phylosticta, Peziza, Candida, and Hydnobolites were the major networking hub in the WWTPs. The overall results in this study highlighted that WWTPs represent a potential source of beneficial fungi for bioremediation of pollutants in the ecosystem and the need to consider human and plant fungal pathogens during safety evaluation of treated wastewater for reuse.

Maternal swimming pool exposure during pregnancy in relation to birth outcomes and cord blood DNA methylation among private well users

Swimming in pools during pregnancy may expose the fetus to water disinfection by-products (DBP). As yet, our understanding of the impacts on DBPs on the fetus is uncertain. Individuals with public water systems are typically exposed to DBPs through drinking, showering and bathing, whereas among those on private water systems, swimming in pools may be the primary exposure source. We analyzed the effects of maternal swimming on birth outcomes and cord blood epigenetic changes in the New Hampshire Birth Cohort Study, a cohort of pregnant women with households on private water systems. Information about swimming in pools during pregnancy was obtained from 1033 women via questionnaires. Swimming pool use and duration were modeled using linear regression with newborn weight, length, and head circumference (z-scores) and genome wide cord blood DNA methylation as the outcomes and with adjustment for potential confounders. Overall 19.7% of women reported swimming in a pool during pregnancy. Among swimmers, duration of swimming was inversely related to head circumference (-0.02 z-score per 10% increase in duration, P = 0.004). No associations were observed with birth weight, length or DNA methylation modifications. Our findings suggest swimming pool exposure may impact the developing fetus although longer-term studies are needed.

Potential transmission pathways of clinically relevant fungi in indoor swimming pool facilities

Possible transmission pathways of fungi in indoor swimming pool facilities were assessed through fungal counting in different areas of the facilities and typing of the collected fungal isolates. Air, water and surface samples were collected from seven different indoor swimming pool facilities. Fungal species were identified based on their internal transcribed spacer (ITS) sequences. Maximum fungal concentrations of 6.2 CFU/cm², 1.39 CFU/100 mL, and 202 CFU/m³ were found on surfaces, in water and air, respectively. In total, 458 isolates were obtained, belonging to 111 fungal species, of which 50 species were clinically relevant. Phialophora oxyspora (13.3%) and Trichosporon dohaense (5.0%) were the most frequently isolated species and were merely detected on floors, as were the dermatophytes, Trichophyton interdigitale and T. rubrum. Penicillium spp. and Aspergillus spp. were the dominant fungi in water and air. No typical patterns of fungal concentrations along the preferential pathways of pool visitors were observed, however, sites where pool visitors converge while moving from one room (e.g. dressing room) to another (e.g. shower room) and walking barefoot displayed the highest fungal concentrations thus posing the highest risk of contamination. The dispersal of fungi on floors is most likely facilitated by the pool visitors and cleaning tools. Clinically relevant fungi, including the ones rarely identified in nature, were widely detected on floors, in water and in air, as well as on cleaning tools and flexibeams. Preventive measures such as cleaning should minimize the prevalence of clinically relevant fungi in swimming pool facilities since these potentially pose health risks to those vulnerable for infections.

Opportunistic Water-Borne Human Pathogenic Filamentous Fungi Unreported from Food

Clean drinking water and sanitation are fundamental human rights recognized by the United Nations (UN) General Assembly and the Human Rights Council in 2010 (Resolution 64/292). In modern societies, water is not related only to drinking, it is also widely used for personal and home hygiene, and leisure. Ongoing human population and subsequent environmental stressors challenge the current standards on safe drinking and recreational water, requiring regular updating. Also, a changing Earth and its increasingly frequent extreme weather events and climatic changes underpin the necessity to adjust regulation to a risk-based approach. Although fungi were never introduced to water quality regulations, the incidence of fungal infections worldwide is growing, and changes in antimicrobial resistance patterns are taking place. The presence of fungi in different types of water has been thoroughly investigated during the past 30 years only in Europe, and more than 400 different species were reported from ground-, surface-, and tap-water. The most frequently reported fungi, however, were not waterborne, but are frequently related to soil, air, and food. This review focuses on waterborne filamentous fungi, unreported from food, that offer a pathogenic potential.

Phoma Infections: Classification, Potential Food Sources, and Its Clinical Impact

Phoma species are phytopathogens that are widely distributed in the environment, most commonly found in aquatic systems and soil. Phoma spp. have the potential to be pathogenic in plants, animals and humans; the latter is a rare occurrence. However, as our immunocompromised population increases, so do the reports of these infections. Medical advances have allowed for the increase in solid organ transplantation; chemotherapies to treat malignancies; and the use of other immunosuppressive agents, which have resulted in a greater population at risk when exposed to diverse fungi including Phoma spp. These fungi have been isolated from water sources, food, and crops; thus acting as opportunistic pathogens when the right host is exposed. Phoma spp. contaminates common food sources such as potatoes and maize, a common species isolated being Phoma sorghina. Though there is potential for causing infection via consumption of contaminated foods, there is insufficient data detailing what levels of organism can lead to an infection, and a regulated process for detecting the organism. The spectrum of disease is wide, depending on the host, ranging from cutaneous infections to invasive diseases. Mortality, however, remains low.