SARS-CoV-2 in wastewater can pose a risk to marine mammals

Endangered marine mammals such as lizards, dolphins, whales and otters are almost as vulnerable to infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) as humans. Researchers at Dalhousie University in Canada Comprehensive environmental science It has discovered human wastewater as a potential mode of coronavirus infection in animals.

If left untreated, SARS-CoV-2 contaminated wastewater can have devastating effects on already declining marine populations. Researchers suggest that managing wastewater, isolating sick mammals, and vaccination are essential to reduce the risk of marine mammals.

Method

The team analyzed the gene sequences of the ACE2 receptors in 36 marine mammals, including whales, dolphins, seals, dugongs, sea otters, and polar bears, and identified the marine mammals at greatest risk of being infected with SARS-CoV. 2.2.

The team also created a list of endangered species from the International Union for Conservation of Nature and understood which endangered species are most at risk from the virus. Killer whales, Pygmy sperm whales, and Sowerby’s beetle were excluded from the data analysis.

They collected data on mutations in ACE2 sequences in both humans and marine mammals and used the MutaBind2 tool to predict the susceptibility to binding affinity for SARS-CoV-2. The team found that mutations in the ACE2 receptor in marine mammals Spike protein, The risk of infection is low.

Mammal population data was superimposed on Alaska’s wastewater levels determined through the Department for Environment and Water in Alaska.

Mutations in the ACE2 receptor alter the binding between the peplomer and the ACE2 receptor

Compared to the human ACE2 receptor, almost all marine mammals had mutations in the ACE2 binding residues of D30 and M82. The exception was the Antarctic minke whale, which has only the M82 mutation. However, the mutation did not alter the binding affinity of the SARS-CoV-2 peplomer to the ACE2 receptor.

California sea lions had 8 of 25 mutations in the ACE2 receptor. This is the most common mutation of all mammalian species observed. Numerous mutations were associated with a substantial decrease in binding affinity between the peplomer and the ACE2 receptor. The dugong had seven mutations that appeared to interfere with the binding of the virus.

Some mammalian species, such as Weddell seals and sea otters, had many mutations in the range of 6-8, but had high binding affinities and an increased risk of infection. In total, about 15 of the 36 species examined had ACE2 mutations that stabilized the virus-receptor interaction.

Researchers have proposed evolutionary perspectives to explain this finding. They speculate that binding stabilization is possible because the virus is closely associated with these particular species. As a result, these 15 mammals are at greatest risk of infection.

Seals, walruses and otters have the highest risk of infection

About 18 of 21 Sertacea Species are more or more sensitive to SARS-CoV-2 in humans. Only the Sourby Cuvier’s beetle was less susceptible to the virus, which may be due to the unique ACE2 receptor mutations in S19P and Q24K.

Many cetaceans, such as bottlenose dolphins and beluga whales, are social and highly vulnerable, making them particularly vulnerable to intraspecific infections with new viruses such as SARS-CoV-2. Is suggested. “The researchers wrote.

Seal species were also more likely to be infected with SARS-CoV-2. The only exception was the California sea lion, which had a new N330D mutation that reduced its binding affinity for the ACE2 protein.

Sea otters were also susceptible to the virus.

Of all the marine mammals studied, the Atlantic walrus had the highest binding affinity for SARS-CoV-2 and therefore the highest risk of infection.

Approximately 15 species are at moderate to high risk of infection and are endangered

More than half of the mammal species studied with moderate to high susceptibility to SARS-CoV-2 were also considered near-threatened, vulnerable, endangered, and endangered.

Researchers suggest that wastewater carrying SARS-CoV-2 infects 15 species and may be at high risk of extinction.

Wastewater that reaches the west coast of Alaska can infect ringed seals and harbor seals that frequently roam the area.

Species of marine mammals that are predicted to be susceptible belong to the IUCN Red List. Many of the species predicted to be susceptible are IUCN RedlistofThreatenedSpecies (https://www.iucnredlist.org). The IUCN Red List is an indicator of global biodiversity and provides the most comprehensive data on the global conservation status of species. Fifteen susceptible species, ranging from moderate to higher than expected human susceptibility, can be identified on the IUCN Red List. The maintenance status updated as of July 25, 2020 was used. The silhouette of the seed is PhyloPic (http://phylopic.org) .S.. Mathavarajah, AK Stoddart, GA Gagnon et al. Science of the Total Environment 760 (2021) 1433465

On the southern coast of Alaska, researchers found that wastewater treatment did not properly eradicate SARS-CoV-2 prior to dumping. This increases the risk of infection of northern sea otter and beluga whale populations.

Given the transmission and extinction risk of coronavirus in mammalian species, researchers advise on bioconservation efforts in managing wastewater. In addition, marine mammals identified as infected with COVID-19 should be quarantined or restricted from access by healthy mammals.

Another possible method is to vaccinate marine mammals as well. “Because of the availability of vaccination technology, wild populations affected by the virus, like humans, Herd immunity Through vaccination. “