Antibiotic resistomes in face-mask biofilm along an urban river: Multiple drivers and co-occurrence with human opportunistic pathogens.

Discarded face masks from the global COVID-19 pandemic have contributed significantly to plastic pollution in surface water, whereas their potential as a reservoir for aquatic pollutants is not well understood. Herein, we conducted a field experiment along a human-impacted urban river, investigating the variations of antibiotic resistance genes (ARGs), pathogens, and water-borne contaminants in commonly-used face masks. Results showed that high-biomass biofilms formed on face masks selectively enriched more ARGs than stone biofilm (0.08-0.22 vs 0.07-0.15 copies/16 S rRNA gene copies) from bulk water, which mainly due to unique microbial communities, enhanced horizontal gene transfer, and selective pressure of accumulated contaminants based on redundancy analysis and variation partitioning analysis. Several human opportunistic pathogens (e.g., Acinetobacter, Escherichia-Shigella, Bacillus, and Klebsiella), which are considered potential ARG carriers, were also greatly concentrated in face-mask biofilms, imposing a potential threat to aquatic ecological environment and human health. Moreover, wastewater treatment plant effluents, as an important source of pollutants to urban rivers, further aggravated the abundances of ARGs and opportunistic pathogens in face-mask biofilms. Our findings demonstrated that discarded face masks provide a hotspot for the proliferation and spread of ARGs and pathogens in urban water, highlighting the urgent requirement for implementing stricter regulations in face mask disposal.

Abandoned disposable masks become hot substrates for plastisphere, whether in soil, atmosphere or water.

A large number of surgical masks (SMs) to be discarded indiscriminately during the spread of COVID-19. The relationship between the changes of masks entering the environment and the succession of the microorganisms on them is not yet clear. The natural aging process of SMs in different environments (water, soil, and atmosphere) was simulated, the changes and succession of the microbial community on SMs with aging time were explored. The results showed that the SMs in water environment had the highest aging degree, followed by atmospheric environment, and SMs in soil had the lowest aging degree. The results of high-throughput sequencing demonstrated the load capacity of SMs for microorganisms, showed the important role of environment in determining microbial species on SMs. According to the relative abundance of microorganisms, it is found that compared with the water environment, the microbial community on SMs in water is dominated by rare species. While in soil, in addition to rare species, there are a lot of swinging strains on the SMs. Uncovering the ageing of SMs in the environment and its association with the colonization of microorganisms will help us understand the potential of microorganisms, especially pathogenic bacteria, to survive and migrate on SMs.

Enrichment of antibiotic resistant genes and pathogens in face masks from coastal environments.

Face masks (FMs) are essential to limit the spread of the coronavirus during pandemic, a considerable of which are accumulated on the coast. However, limited is known about the microbial profile in the biofilm of the face masks (so-called plastisphere) and the impacts of face masks on the surrounding environments. We herein performed face mask exposures to coastal sediments and characterized the microbial community and the antibiotic resistome. We detected 64 antibiotic-resistance genes (ARGs) and 12 mobile gene elements (MGEs) in the plastisphere. Significant enrichments were found in the relative abundance of total ARGs in the plastisphere compared to the sediments. In detail, the relative abundance of tetracycline, multidrug, macrolide-lincosamide-streptogramin B (MLSB), and phenicol-resistant genes had increased by 5-10 times. Moreover, the relative abundance of specific hydrocarbonoclastic bacteria (e.g., Polycyclovorans sp.), pathogens (e.g., Pseudomonas oleovorans), and total MGEs significantly increased in the sediments after face mask exposure, which was congruent with the alteration of pH value and metal concentrations in the microcosms. Our study demonstrated the negative impacts of FMs on coastal environments regardless of the profiles of ARGs or pathogens. These findings improved the understanding of the ecological risks of face masks and underlined the importance of beach cleaning.

Eukaryotic community succession on discarded face masks in the marine environment.

Wearing facemasks remains an essential strategy for combating the COVID-19 pandemic. However, used masks are becoming plastic wastes that are widespread in the oceans, which is raising concerns about the potential impacts of these novel plastic niches on marine organisms. To delve into this issue, we exposed surgical masks to coastal waters for 30 days. Valuable information was recorded weekly in regard to the succession of the eukaryotic community inhabiting the masks via high-throughput 18S rRNA gene sequencing. Generally, the community on masks was significantly distinct from that in the surrounding seawater. With 1150 different eukaryotic taxa identified, the diversity of the vigorous colonizers of masks peaked at the beginning and decreased over time. A hallmark of initial colonization was the aggregation of diatoms, which formed biofilms on masks, followed by dinoflagellates that acted as a turning point for subsequent development of calcified species and other predators. This study provides insight into the eukaryotic community dynamics on discarded masks in the marine environment and highlights that the potential mask-mediated harmful species clustering may threaten the marine ecosystem.

COVID-19 Generated Personal Protective Equipment: Sources of Microplastics and Pathogen Vectors in Marine Environments?

The world has already been experienced the severe adverse effects of COVID-19 at every levels. When it is understood that the COVID-19 infection is spread in the community via respiratory transmission from human, then the widespread use of plastic-made personal protective equipments (PPEs) like face masks and hand gloves have tremendously increased throughout the world. Although it has reduced the spreading of virus, however, careless disposal or mismanagement of these single use PPEs has created another major concern for the environment as plastics are known source of environmental contamination. In one hand, they are infected with SARS-CoV-2, while in the other, they act as a carrier or vector or pathways for other pathogens or diseases, and hence can increase the degree of continuing pandemic. Besides, there might have chance that plastics or microplastics may be responsible for introducing new pathogenic viruses or bacteria to humankind. As such, it is clear that more research needs to be conducted to clarify this fact, and its underlying mechanisms. In this review, we briefly explored how PPEs used in the COVID-19 pandemic aggravated existing microplastic pollution, how they could act as disease routes or vectors, and how they could introduce new pathogens to the terrestrial and marine environment. Addressing these questions may create awareness in plastic use, waste management and enacting relevant policy which may protect our environment and health.

Discarded masks as hotspots of antibiotic resistance genes during COVID-19 pandemic.

The demand for facial masks remains high. However, little is known about discarded masks as a potential refuge for contaminants and to facilitate enrichment and spread of antibiotic resistance genes (ARG) in the environment. We address this issue by conducting an in-situ time-series experiment to investigate the dynamic changes of ARGs, bacteria and protozoa associated with discarded masks. Masks were incubated in an estuary for 30 days. The relative abundance of ARGs in masks increased after day 7 but levelled off after 14 days. The absolute abundance of ARGs at 30 days was 1.29 × 1012 and 1.07 × 1012 copies for carbon and surgical masks, respectively. According to normalized stochasticity ratio analysis, the assembly of bacterial and protistan communities was determined by stochastic (NST = 62%) and deterministic (NST = 40%) processes respectively. A network analysis highlighted potential interactions between bacteria and protozoa, which was further confirmed by culture-dependent assays, that showed masks shelter and enrich microbial communities. An antibiotic susceptibility test suggested that antibiotic resistant pathogens co-exist within protozoa. This study provides an insight into the spread of ARGs through discarded masks and highlights the importance of managing discarded masks with the potential ecological risk of mask contamination.

Extensive use of face masks during COVID-19 pandemic: (micro-)plastic pollution and potential health concerns in the Arabian Peninsula.

Face masks are primary line of defense to reduce the transmission risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). World Health Organization (WHO) has already updated the guidelines and advised the use of face masks in public areas essentially. This has dramatically increased the production and use of face masks in many parts of the world. Arabian Peninsula is comprised of six countries where the public perception of following WHO guidelines is high. In this study, we highlight the concerns relating to extensive use of face masks in this region, particularly in the context of (micro-)plastic pollution. We computed the number of face masks to be used in each of the countries of Arabian Peninsula for varying levels of acceptance rate and average number of daily usages. Accordingly, the amount of (micro-)plastic that could come into the terrestrial and marine environment is also reported. Saudi Arabia, being the most populated country in the region may contribute up to 32-235 thousand tons of (micro-)plastic which is nearly half of the amount in the whole Peninsula. On the other hand, an extremely high infection rate in Qatar (25.74%) may also lead to a significant increase of (micro-)plastic content due to high public acceptance rate and living standards. The high (micro-)plastic fraction is of significant concern because it ends up in the marine ecosystems. Further, it allows colonization of several pathogenic microorganisms (bacteria, viruses, fungal filaments, and spores) and might serve as carriers of disease transmission finally affecting the living organisms habituating these ecosystems. It is suggested that appropriate regulations on face masks waste should be devised to avoid any unwanted consequences in the near future.