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Toronto, May 7: Scientists have uncovered how bats can carry the MERS coronavirus without getting sick, shedding light on what triggers coronaviruses, including the one behind the COVID-19 pandemic, to jump to humans.

According to the study, published in the journal Scientific Reports, coronaviruses like the Middle East respiratory syndrome (MERS) virus, and the COVID19-causing SARS-CoV-2 virus, are thought to have originated in bats.

While these viruses can cause serious, and often fatal disease in people, bats seem unharmed, the researchers, including those from the University of Saskatchewan (USask) in Canada, said.

"The bats don't get rid of the virus and yet don't get sick. We wanted to understand why the MERS virus doesn't shut down the bat immune responses as it does in humans," said USask microbiologist Vikram Misra.

In the study, the scientists demonstrated that cells from an insect-eating brown bat can be persistently infected with MERS coronavirus for months, due to important adaptations from both the bat and the virus working together.

"Instead of killing bat cells as the virus does with human cells, the MERS coronavirus enters a long-term relationship with the host, maintained by the bat's unique 'super' immune system," said Misra, one of the study's co-authors.

"SARS-CoV-2 is thought to operate in the same way," he added.

Stresses on bats, such as wet markets, other diseases, and habitat loss, may have a role in coronavirus spilling over to other species, the study noted.

"When a bat experiences stress to their immune system, it disrupts this immune system-virus balance and allows the virus to multiply," Misra said.

The scientists, involved in the study, had earlier developed a potential treatment for MERS-CoV, and are currently working towards a vaccine against COVID-19.

While camels are the known intermediate hosts of MERS-CoV, they said bats are suspected to be the ancestral host.

There is no vaccine for either SARS-CoV-2 or MERS, the researchers noted.

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"We see that the MERS coronavirus can very quickly adapt itself to a particular niche, and although we do not completely understand what is going on, this demonstrates how coronaviruses are able to jump from species to species so effortlessly," said USask scientist Darryl Falzarano, who co-led the study.

According to Misra, coronaviruses rapidly adapt to the species they infect, but little is known on the molecular interactions of these viruses with their natural bat hosts.

An earlier study had shown that bat coronaviruses can persist in their natural bat host for at least four months of hibernation.

When exposed to the MERS virus, the researchers said, bat cells adapt, not by producing inflammation-causing proteins that are hallmarks of getting sick, but instead by maintaining a natural antiviral response.

On the contrary, they said this function shuts down in other species, including humans.

The MERS virus, the researchers said, also adapts to the bat host cells by very rapidly mutating one specific gene.

These adaptations, according to the study, result in the virus remaining long-term in the bat, but being rendered harmless until something like a disease, or other stressors, upsets this balance.

In future experiments, the scientists hope to understand how the bat-borne MERS virus adapts to infection and replication in human cells.

"This information may be critical for predicting the next bat virus that will cause a pandemic," Misra said.

New Delhi, Jul 19: Indian equities will be driven by a host of factors like corporate earnings, coronavirus cases trend and geo-political developments this week, according to analysts.

Market participants will also keenly watch the progress of monsoon, with experts saying that the farm sector revival will play a key role in lifting the coronavirus-hit economy.

"With no major event, the ongoing earnings season and global cues will continue to dictate the market trend. Besides, the progress of monsoon will also be closely watched," Ajit Mishra, VP - Research, Religare Broking, said.

Globally, the rising coronavirus infections and geo-political tensions have created uncertainty on the economic recovery front.

With India's COVID-19 cases fast approaching the 11 lakh mark, the third-highest behind the US and Brazil, and the death toll nearing 27,000, participants are expected to tread cautiously going forward.

At global level, confirmed COVID-19 cases have crossed 1.4 crore and deaths totalled about 6 lakh.

Markets globally will closely follow developments on the trade and political level between the US and China, according to analysts.

"We would continue witnessing stock-specific action as the earnings season unfold. Though the near-term momentum looks positive, we would advise traders to be cautious, given flaring US-China trade relations, persistent rise in virus cases and implementation of fresh lockdowns in parts of the country," said Siddhartha Khemka, Head - Retail Research, Motilal Oswal Financial Services Ltd.

HDFC Bank will remain in focus on Monday after having announced its June quarter earnings on Saturday.

The lender reported 19.6 per cent rise in its standalone net profit at Rs 6,658.62 crore for April-June 2020; while its income rose to Rs 34,453.28 crore during the quarter.

Other major companies to announce their quarterly results this week are Axis Bank, Bajaj Finance, Hindustan Unilever Limited, Bajaj Auto and ITC.

"Going ahead market participants will closely track the development related to covid vaccine, the rising infection of coronavirus, development on economic activities, corporate earnings and US-China relationship," said Sumeet Bagadia, Executive Director, Choice Broking.

On weekly basis, the Sensex gathered 425.81 points or 1.16 per cent, and the Nifty gained 133.65 points or 1.24 per cent.

Bhopal, Jul 25: Madhya Pradesh chief minister Shivraj Singh Chouhan said on Saturday he has tested positive for the coronavirus disease (Covid-19).

Chouhan made the announcement in a series of tweets.

“My dear countrymen, I had symptoms of COVID-19 and after the test, my report has come back positive. I appeal to all my colleagues that whoever came in contact with me, must get their corona test done. And my close contacts should quarantine themselves,” Chouhan said in a tweet in Hindi.

“If COVID19 is treated on time, a person is completely cured. I have been reviewing the status of corona infection every evening since March 25. I will try to review corona situation through video conferencing as much as possible now,” he added.

The chief minister said the review meeting will now be held by home minister Narottam Mishra, urban development and administration minister Bhuppendra Singh, health education minister Vishvas Sarang and health minister Dr Prabhuram Choudhary in his absence.

“I will also continue to do everything possible to help control COVID19 in the state during treatment,” he said.

One of Chouhan’s ministerial colleagues tested positive for Covid-19 late on July 22.

The chief minister along with the minister, the Bharatiya Janata Party’s state unit president VD Sharma and state unit general secretary (organisation) Suhas Bhagat had visited Lucknow in a government plane on July 21 to attend the funeral of MP governor Lalji Tandon who died away in the Uttar Pradesh capital, his hometown. during hospitalisation.

The minister is admitted to a private medical college’s teaching hospital in Bhopal.