Antibiotic resistance, a significant public health hazard, is predicted to cause 10 million deaths worldwide by 2050. The study aimed to identify culturable bioaerosols in the indoor air of dental units in Lahore and assess their antibiotic resistance. Air samples were collected from 10 dental unit locations at different distances, with average concentrations of fungi and bacteria falling within intermediate ranges, per the Global Index of Microbial Contamination (GIMC/m3) index. The study found higher antibiotic-resistant strains in hospital dental units, particularly during winter. The most vigorous strain, S.aureus-NAJIH18, exhibited 70% resistance to ceftazidime. The research highlights the importance of quantifying microbial pollutants for evaluating their source and complexity. It suggests proactive mitigation techniques, such as focused cleaning and air filtration, to improve indoor air quality can mitigate the spread of antibiotic-resistant strains. These insights offer hope in combating the growing public health threat of antibiotic resistance.

In this study, we investigated the concentration of airborne influenza virus in daycare centers and influencing factors, such as common cold prevalence, air pollutants, and meteorological factors. A total of 209 air samples were collected from daycare centers in Kaohsiung and the influenza virus was analyzed using real-time quantitative polymerase chain reaction. Air pollutants and metrological factors were measured using real-time monitoring equipment. Winter had the highest positive rates of airborne influenza virus and the highest prevalence of the common cold, followed by summer and autumn. The concentration of CO was significantly positively correlated with airborne influenza virus. Daycare center A, with natural ventilation and air condition systems, had a higher concentration of airborne influenza A virus, airborne fungi, and airborne bacteria, as well as a higher prevalence of the common cold, than daycare center B, with a mechanical ventilation system and air purifiers, while the concentrations of CO2, CO, and UFPs in daycare center A were lower than those in daycare center B. We successfully detected airborne influenza virus in daycare centers, demonstrating that aerosol sampling for influenza can provide novel epidemiological insights and inform the management of influenza in daycare centers.

Human activities are a significant contributor to the spread of antibiotic resistance genes (ARGs), which pose a serious threat to human health. These ARGs can be transmitted through various pathways, including air, within the context of One Health. This study used metagenomics to monitor the resistomes in urban air from two critical locations: a wastewater treatment plant and a hospital, both indoor and outdoor. The presence of cell-like structures was confirmed through fluorescence microscopy. The metagenomic analysis revealed a wide variety of ARGs and a high diversity of antibiotic-resistant bacteria in the airborne particles collected. The wastewater treatment plant showed higher relative abundances with 32 ARG hits per Gb and m3, followed by the main entrance of the hospital (indoor) with ≈5 ARG hits per Gb and m3. The hospital entrance exhibited the highest ARG richness, with a total of 152 different ARGs classified into nine categories of antibiotic resistance. Common commensal and pathogenic bacteria carrying ARGs, such as Moraxella, Staphylococcus and Micrococcus, were detected in the indoor airborne particles of the hospital. Interestingly, no ARGs were shared among all the samples analysed, indicating a highly variable dynamic of airborne resistomes. Furthermore, the study found no ARGs in the airborne viral fractions analysed, suggesting that airborne viruses play a negligible role in the dissemination of ARGs.

The aim of this paper was to evaluate the degree of mycological air contamination and determine the taxonomic diversity of airborne fungi residing in the air of 20 different animal facilities in a zoological garden. The concentrations of fungi in the zoological garden were measured using a MAS-100 air sampler. The collected microorganisms were identified using the combination of molecular and morphological methods. The fungal concentration ranged from 50 to 3.65 × 104 CFU/m3 during the whole study. The quantitative analysis of the fungal aerosol showed that the obtained concentration values were lower than the recommended permissible limits (5 × 104 CFU/m3 for fungi). Environmental factors, including temperature and relative humidity, exerted a varying effect on the presence and concentration of isolated fungi. Relative humidity was shown to correlate positively with the concentration of fungal spores in the air of the facilities studied (rho = 0.57, p < 0.0021). In parallel, no significant correlation was established between temperature and total fungal concentration (rho =  - 0.1, p < 0.2263). A total of 112 fungal strains belonging to 50 species and 10 genera were isolated. Penicillium was the dominant genera, including 58.9% of total fungal strains, followed by Aspergillus 25.89%, Cladosporium 3.57%, Talaromyces 3.57%, Mucor 1.78%, Schizophyllum 1.78%, Syncephalastrum 0.89%, Alternaria 0.89%, Absidia 0.89%, and Cunninghamella 0.89%. Our preliminary studies provide basic information about the fungal concentrations, as well as their biodiversity in zoological garden. Further studies are needed to generate additional data from long-term sampling in order to increase our understanding of airborne fungal composition in the zoological garden.

Aspergillus niger (A. niger) spores can induce numerous health problems. Once the airflow-imposed drag force on an A. niger spore exceeds its binding force with the colony, the spore is detached. Turbulent flow may considerably increase the spore detachment. No method is currently available for prediction of the drag force on a spore and its detachment in turbulent flows. This investigation measured the turbulent velocities and detachment of A. niger colonies in a wind tunnel. Computational fluid dynamics (CFD) was employed to model an A. niger unit subjected to turbulent flow blowing. The top 1 % quantile instantaneous velocity of the turbulent flow was specified as the steady entry flow boundary condition for solving the peak velocity distribution and the peak drag forces onto spores. The predicted spore detachment ratios were compared with the measurement data for model validation. The results revealed that the spore detachment ratios with a turbulence intensity of 17 % to 20 % can be twice to triple the ratio with a turbulence intensity of approximately 1 %, when the average velocity for blowing remains the same. The proposed CFD model can accurately predict the detachment ratios of the A. niger spores. ENVIRONMENTAL IMPLICATION: Some people are sensitive to the Aspergillus niger (A. niger) spores, and excessive exposure can cause nasal congestion, skin tingling, coughing, and even asthma. Turbulent flow can considerably increase the spore detachment, due to the increased airflow-imposed drag force on the spores during turbulence. This investigation developed a numerical model to solve for the peak velocity distribution and the peak drag forces onto spores in turbulent flows to predict the spore detachment. With the numerical tool, the airborne fungal spore concentrations would be predictable, which paves a way for intelligent and precise control of fungal aerosol pollution.

Outbreaks of airborne viral emerging infectious diseases (EIDs) cause an increasing burden on global public health, particularly with a backdrop of intensified climate change. However, infection sources and drivers for outbreaks of airborne viral EIDs remain unknown. Here, we aim to explore the driving mechanisms of outbreaks based on the one health perspective. Outbreak information for 20 types of airborne viral EIDs was collected from the Global Infectious Disease and Epidemiology Network database and a systematic literature review. Four statistically significant and high-risk spatiotemporal clusters for airborne viral EID outbreaks were identified globally using multivariate scan statistic tests. There were 112 outbreaks with clear infection sources, and zoonotic spillover was the most common source (95.54%, 107/112). Since 1970, the majority of outbreaks occurred in healthcare facilities (24.82%), followed by schools (17.93%) and animal-related settings (15.93%). Significant associations were detected between the number of earthquakes, storms, duration of floods, and airborne viral EIDs\' outbreaks using a case-crossover study design and multivariable conditional logistic regression. These findings implied that zoonotic spillover and extreme weather events are driving global outbreaks of airborne viral EIDs, and targeted prevention and control measures should be made to reduce the airborne viral EIDs burden.

In the last decade, extensive fungal growth has developed in Danish museums parallel to climate change, challenging occupational health and heritage preservation. The growth was unexpected as the museums strived to control relative humidity below 60 %, and it should exceed 75 % to risk growth. A Danish case study found xerophilic Aspergillus species able to grow at low relative humidity in a museum repository. This cross-sectional study aimed to examine whether xerophilic growth from Aspergillus section Restricti has become a novel contaminant nationally distributed in Danish museum repositories striving to control relative humidity according to international environmental recommendations for heritage collections. The study examined The National Museum of Denmark and eight large State Recognized museums distributed throughout Denmark. It was based on 600 swab and tape-lift samples and 60 MAS100-Eco and filter air samples analyzed for fungi with cultivation and morphological identification, Big-Dye-Sanger sequencing, CaM-Nanopore and ITS-Illumina amplicon sequencing. The study showed growth from seven xerophilic Aspergillus species: A. conicus, A. domesticus, A. glabripes, A. halophilicus, A. magnivesiculatus, A. penicilloides, A. vitricola, of which three are new to Denmark, and 13 xerotolerant Aspergillus species. There was no growth from other fungal species. The multiple detection approach provided a broad characterization; however, there was variance in the detected species depending on the analysis approach. Cultivation and Big-Dye Sanger sequencing showed the highest Aspergillus diversity, detecting 17 species; CaM-Nanopore amplicon sequencing detected 12 species; and ITS-illumina amplicon sequencing detected two species but the highest overall diversity. Cultivation, followed by Big-Dye Sanger and CaM-amplicon sequencing, proved the highest compliance. The study concluded that xerophilic Aspergillus growth is nationally distributed and suggests species from Aspergillus section Restricti as a novel contaminant in climate-controlled museum repositories. To safeguard occupational health and heritage preservation research in sustainable solutions, avoiding xerophilic growth in museum collections is most important.

This research builds upon a previous study that explored the potential of the modified WIBS-4+ to selectively differentiate and detect different bioaerosol classes. The current work evaluates the influence of meteorological and air quality parameters on bioaerosol concentrations, specifically pollen and fungal spore dynamics. Temperature was found to be the most influential parameter in terms of pollen production and release, showing a strong positive correlation. Wind data analysis provided insights into the potential geographic origins of pollen and fungal spore concentrations. Fungal spores were primarily shown to originate from a westerly direction, corresponding to agricultural land use, whereas pollen largely originated from a North-easterly direction, corresponding to several forests. The influence of air quality was also analysed to understand its potential impact on the WIBS fluorescent parameters investigated. Most parameters had a negative association with fungal spore concentrations, whereas several anthropogenic influences showed notable positive correlations with daily pollen concentrations. This is attributed to similar driving forces (meteorological parameters) and geographical origins. In addition, the WIBS showed a significant correlation with anthropogenic pollutants originating from combustion sources, suggesting the potential for such modified spectroscopic instruments to be utilized as air quality monitors. By combining all meteorological and pollution data along with WIBS-4+ channel data, a set of Multiple Linear Regression (MLR) analyses were completed. Successful results with R2 values ranging from 0.6 to 0.8 were recorded. The inclusion of meteorological parameters was dependent on the spore or pollen type being examined.

Airborne microorganisms in food processing environments pose a potential risk for food product contamination. Yet, the absence of established standards or guidelines setting quantitative limits on airborne microorganisms underscores a critical gap in current regulatory frameworks. This review seeks to explore the feasibility of establishing quantitative limits for airborne microorganisms in food processing facilities, aiming to provide evidence-based guidance to enhance food safety practices in the industry. The review begins by addressing the complexities of microbial air quality in the food industry through a general literature search covering sources of airborne microorganisms, factors affecting particle deposition, air sampling methods and preventive measures. Subsequently, it employs a structured approach to assess the significance of air quality and its impact on product quality. Utilizing the PRISMA method, relevant scientific literature from May 2002 to May 2022 was examined, resulting in 26 articles meeting inclusion criteria from a pool of 11,737 original research papers. Additionally, the review investigates existing probability models for assessing airborne contamination to enhance air quality risk assessment in food safety management systems. The literature reveals a lack of substantial evidence supporting a direct correlation between airborne microorganisms and food contamination. The absence of standardized air sampling methodologies in previous studies hinders the comparability and reliability of research findings. Additionally, the literature fails to establish a conclusive relationship between influencing factors such as total particle counts, temperature, relative humidity and airborne contamination. Contradictory probability models for quantifying airborne contamination, and the absence of tailored preventive measures, hinder effective control and undermine microbial contamination control in diverse food processing contexts. In conclusion, the development of numeric guidelines for airborne contamination necessitates a tailored approach, considering factors such as product characteristics and production context. By integrating risk assessment models into this process, a more thorough comprehension of contamination risks can be achieved, providing tailored guidance based on the identified risk levels for each product. Ongoing collaborative efforts are essential to develop evidence-based guidelines that effectively mitigate risks without incurring unnecessary costs.

Airborne pathogens severely threaten public health worldwide. Air disinfection is essential to ensure public health. However, excessive use of disinfectants may endanger environmental and ecological security due to the residual disinfectants and their by-products. This study systematically evaluated disinfection efficiency, induction of multidrug resistance, and the underlying mechanisms of disinfectants (NaClO and H2O2) on airborne bacteria. The results showed that airborne bacteria were effectively inactivated by atomized NaClO (>160 μg/L) and H2O2 (>320 μg/L) after 15 min. However, some bacteria still survived after disinfection by atomized NaClO (0-80 μg/L) and H2O2 (0-160 μg/L), and they exhibited significant increases in antibiotic resistance. The whole-genome sequencing of the resistant bacteria revealed distinct mutations that were responsible for both antibiotic resistance and virulence. This study also provided evidences and insights into possible mechanisms underlying the induction of antibiotic resistance by air disinfection, which involved intracellular reactive oxygen species formation, oxidative stress responses, alterations in bacterial membranes, activation of efflux pumps, and the thickening of biofilms. The present results also shed light on the role of air disinfection in inducing antibiotic resistance, which could be a crucial factor contributing to the global spread of antibiotic resistance through the air.