Tiger in US zoo tests positive for coronavirus, becomes first animal to get COVID-19

The first animal started showing symptoms March 27, and all are doing well and expected to recover, said the zoo, which has been closed to the public since March 16 amid the surging coronavirus outbreak in New York.

A tiger at the Bronx Zoo has tested positive for the new coronavirus, in what is believed to be the first known infection in an animal in the U.S. or a tiger anywhere, federal officials and the zoo said Sunday.

The 4-year-old Malayan tiger named Nadia — and six other tigers and lions that have also fallen ill — are believed to have been infected by a zoo employee who wasn’t yet showing symptoms, the zoo said. The first animal started showing symptoms March 27, and all are doing well and expected to recover, said the zoo, which has been closed to the public since March 16 amid the surging coronavirus outbreak in New York.

The test result stunned zoo officials: “I couldn’t believe it,” director Jim Breheny said. But he hopes the finding can contribute to the global fight against the virus that causes COVID-19.

“Any kind of knowledge that we get on how it’s transmitted, how different species react to it, that knowledge somehow is going to provide a greater base resource for people,” he said in an interview.

The finding raises new questions about transmission of the virus in animals. The U.S. Department of Agriculture, which confirmed Nadia’s test result at its veterinary lab, said there are no known cases of the virus in U.S. pets or livestock.

“There doesn’t appear to be, at this time, any evidence that suggests that the animals can spread the virus to people or that they can be a source of the infection in the United States,” Dr. Jane Rooney, a veterinarian and a USDA official, said in an interview.

The USDA said Sunday it’s not recommending routine coronavirus testing of animals, in zoos or elsewhere, or of zoo employees. Still, Rooney said a small number of animals in the U.S. have been tested through the USDA’s National Veterinary Services Laboratories, and all those tests came back negative except Nadia’s.

The coronavirus outbreaks around the world are driven by person-to-person transmission, experts say.

There have been a handful of reports outside the U.S. of pet dogs or cats becoming infected after close contact with contagious people, including a Hong Kong dog that tested positive for a low level of the pathogen in February and early March. Hong Kong agriculture authorities concluded that pet dogs and cats couldn’t pass the virus to human beings but could test positive if exposed by their owners.

Some researchers have been trying to understand the susceptibility of different animal species to the virus, and to determine how it spreads among animals, according to the Paris-based World Organization for Ani

Symptoms of covid 19

 Pbe sick with the virus for 1 to 14 days before developing symptoms. The most common symptoms of coronavirus disease (COVID-19) are fever, tiredness, and dry cough. Most people (about 80%) recover from the disease without needing special treatment.

More rarely, the disease can be serious and even fatal. Older people, and people with other medical conditions (such as asthma, diabetes, or heart disease), may be more vulnerable to becoming severely ill.

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People may experience:

cough

fever

tiredness

difficulty breathing (severe cases

There’s currently no vaccine to prevent coronavirus disease (COVID-19).

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You can protect yourself and help prevent spreading the virus to others if you:

Do

Wash your hands regularly for 20 seconds, with soap and water or alcohol-based hand rub

Cover your nose and mouth with a disposable tissue or flexed elbow when you cough or sneeze

Avoid close contact (1 meter or 3 feet) with people who are unwell

Stay home and self-isolate from others in the household if you feel unwell

Don't

Touch your eyes, nose, or mouth if your hands are not clean

Molecular Weight, Molecular Mass, and TheirCorrect Units.

There are two common (and equivalent) ways to de￾scribe molecular mass; both are used in this text.
 Thef is molecular weight, or relative molecular mass,
denoted Mr. The molecular weight of a substance is de￾fined as the ratio of the mass of a molecule of that sub￾stance to one-twelfth the mass of carbon-12 (12C).
Since Mr is a ratio, it is dimensionless—it has no asso￾ciated units. The second is molecular mass, denoted
m. This is simply the mass of one molecule, or the mo￾lar mass divided by Avogadro’s number. The molecu￾lar mass, m, is expressed in daltons (abbreviated Da).
One dalton is equivalent to one-twelfth the mass of
carbon-12; a kilodalton (kDa) is 1,000 daltons; a mega￾dalton (MDa) is 1 million daltons.
Consider, for example, a molecule with a mass
1,000 times that of water. We can say of this molecule
either Mr  18,000 or m  18,000 daltons. We can also
describe it as an “18 kDa molecule.” However, the ex￾pression Mr  18,000 daltons is incorrect.
Another convenient unit for describing the mass
of a single atom or molecule is the atomic mass unit
(formerly amu, now commonly denoted u). One
atomic mass unit (1 u) is defined as one-twelfth the
mass of an atom of carbon-12. Since the experimen￾tally measured mass of an atom of carbon-12 is
1.9926  10 23 g, 1 u  1.6606  10 24 g. The atomic
mass unit is convenient for describing the mass of a
peak observed by mass spectrometry (see 

What are the advantages and disadvantages of biotechnology

Biotechnology involves genetic engineering, which in nothing but transferring gene from one and inserting them into another species. Biotechnology has seemed to have improved the conditions of living, yet with all its promises it has its wide disadvantages too.

Advantages:

• Higher crop yields.
• Higher resistance to diseases.
• Less pesticide is needed to be used due to insect pest resistant plants.
• GMO crops last longer. This decreases the amount of wasted crops and foods.
• Reduced energy needs to produce GMO crops.
• Decrease in costs of growing and farming, due to the reduced use of pesticides. Farmers have more income, which they could spend on such things as, for example, the education of their children.
• More economically friendly as pesticides do not go into the air, soil, and water (especially freshwater supplies). Their production hazards to the environment also decreases.
• In the corn market, Monsanto’s triple-stack corn which combines Roundup Ready 2 weed control technology with YieldGard Corn Borer and YieldGard Rootworm insect control.
• Less starvation in the world due to decreased food prices.
• More nutritious. This has been proven and tested many times.
• Creation of “super foods” due to better knowledge. Super foods are types of food that are cheap to produce, grow fast in large quantities, highly nutritious.
• New products. For examples, scientist identified the gene responsible for caffeine in coffee beans; by excluding this gene, decaffeinated coffee beans can be grown naturally.
• Reduction of sicknesses and illnesses, as GMO crops are more nutritious. Vitamins and minerals can be provided to children and to people, where they were inaccessible before (i.e.: the world’s poorest and/or most secluded areas).
• Developments of new kinds of crops that can be grown at extreme climates, for example, dry or freezing environments (like deserts). For example, scientist developed a type of tomato that grows in salty soil.

Disadvantages:

Ramification to human health

Human Breast Cancer: GMOs in our food allows for greater herbicide and pesticide used over time many of which are known endocrine disruptors. The Breast Cancer Fund has released a publication, “State of the Evidence” that connects environmental toxins to breast cancer. Some of the pesticides that they identified as causing mammary glands include propazine, cyanazine, chlordane, methhyl bromide, malathion, and 2,4-D.

Lung cancer: From the chemical-lined bag to the actual contents, microwave popcorn is at the center of lung cancer debates around the world. Not only are the kernels and oil likely GMO (which the manufacturer does not have to disclose), but the fumes released contain diacetyl, which is toxic to humans.

• Spread of new, more resistant "super weeds”. Spread of new, more resistant "super pests". Major trading countries that obtain most of the benefit from the production and trade of genetically modified crops. This might cause more geopolitical conflicts.
• Possible damages to the environment.
• Additional costs of labeling whether products are GMOs or not. This might increase costs of foods.
• Widening corporate size gaps between food producing giants and smaller ones. This might cause a consolidation in the market: fewer competitors increase the risk of oligopolies, which might increase food prices.
• Larger companies might have more political power. They might be able to influence safety and health standards (example: less stringent regulations, standards and requirements).
• Harm to other organisms. For example, genes and their effect included in a crop may turn out to be poisonous to insects (monarch butterfly poisoned by GMO corns).
• Cross-pollination with traditional, organic plants. Cross pollination can occur at quite large distances. New genes may also be included in the offspring of the traditional, organic crops miles away. This makes it difficult to distinguish which crop field is organic, and which is not, posing a problem to the proper labeling of non-GMO food products.
• Allergies may become more intense, and also, new allergy types may develop.

Importance of plasmid in Biotechnology

Plasmid is a small circle DNA,typically found in bacteria,that is separate from the majority of bacterial DNA located in the nucleoid. Specifically,plasmids are nonessential extra chromosomal pieces of DNA which usually contains between 5 and 100 genes that are not required for the survival of the bacteria.

Plasmid is actually a vehicle for storing and studying genes.Scientists use it in laboratory experiments as a vector for DNA of interest,typically a gene, they are usually represented by a simple circle inside a cell.

To be an effective tool for scientists, a plasmid typically possesses three basics feature or importance:

• A multiple cloning site.
• An origin of replication,and
• A selectable marker.

Now let’s see how these plasmid features plays a key role in genetically engineering bacteria to produce human insulin. If the main purpose of a plasmid is to serve as a vehicle for genes of interest,we need to be able to insert the human insulin gene into the plasmid. This is the purpose of Multiple Cloning Site.A Multiple Cloning Site is the location in a plasmid where a sequence of DNA,typically a gene, can be inserted. Once a gene is inserted into a plasmid, you obviously don’t want to lose it. Wouldn't it be great if the bacteria did all the work maintaining the plasmid for us ? Actually,that’s one main reasons scientists put a gene into a bacterial plasmid. The origin of replication is the place where the process of DNA replication begins. Therefore, if our plasmid possesses an origin of replication (ori.) the bacteria will automatically make a new copy of the plasmid during the replication process (DNA replication creates an exact copy of DNA in the cell). This means that the two daughter cells both receive a copy of the DNA found in the mother cell when the mother cell divides. If our genetically engineered plasmid has an origin of replication, it is also replicated creating a two daughter cells both containing the gene of interest (GOI). A plasmid also possess a selectable marker, selectable marker is an element that is required for the maintenance of the plasmid in the cell. Due to the presence of the selective marker, the plasmid becomes useful for the cell. Under the selective conditions, only cells that contain plasmids with the appropriate selectable marker can survive. Commonly, genes that confer resistance to various antibiotics are used as selective markers in cloning vectors.

What is the difference between pour plate method and spread plate method in isolation of bacterial colonies

Pour-plate method and Spread-plate method are used for quantification or enumeration of bacterial sample.

The difference between pour-plate method and spread-plate method are as follows:-

[A] Procedure: -

For pour plate-

• Inoculum from a sample is placed in the center of sterile Petri dish using a sterile pipette. Molten cooled agar (approx. 15mL) is then poured into the Petri dish containing the inoculum.

For spread plate-

• Inoculum from a sample is pipette out and spread evenly on sterile nutrient Agar by spreader.

[B] Amount of Inoculum:-

For pour plate-

• Inoculum is more i.e 1ml

For spread plate-

• Inoculum is less i.e. 0.1ml

[C] Growth of colonies:-

For pour plate-

• Colonies grow in and on solidified medium.

For spread plate-

• Colonies grow only on surface of medium.

[D] Mixing of inoculum and medium:-

For pour plate-

• After pouring molten agar on inoculum the plate is gently swirl.

For spread plate-

• Inoculum is spread on surface of medium (agar) by sterile glass rod spreader.

[E] Surface area covered by sample:-

In pour plate-

• More surface area is covered as the sample is spread throughout the media.

In spread plate-

• Sample is spread only to a limited area i.e. only on the surface of agar.

[F] Uses:-

For pour plate-

• It is used to determine CFU/ml or PFU/ml.

For spread plate-

• It is used to isolate specific clonal colonies.

[G] Advantage:-

Pour plate-

1. It allows the growth of microaerophiles.
2. It helps in identification of bacteria, i.e. whether the bacteria is an aerobe, anaerobe or facultative aerobe.

Spread plate-

1. Picking surface colony will not interrupt other colonies by digging out of agar.
2. Get even distribution of colonies.

[H ] Disadvantage:-

For pour plate-

1. Picking subsurface colonies can interrupt other colonies by digging out of agar.
2. Don't get even distribution of colonies.

For spread plate-

1. It doesn't allow growth of microaerophiles.
2. It doesn't allow growth of obligate anaerobes.

[I] Benefits:-

For pour plate-

• It is beneficial to isolate certain bacteria which are motile and don't grow as colony.

For spread plate-

• It is beneficial for isolation of bacteria from soil or water

Why do we use a nitrocellulose membrane in western blot

Nitrocellulose membranes are a popular matrix used in protein blotting because of

1. Their high protein-binding affinity
2. Compatibility with a variety of detection methods (chemiluminescence, chromogenic, and fluorescence), and
3. The ability to immobilize proteins, glycoproteins, or nucleic acids.

Protein immobilization is thought to occur by hydrophobic interactions, and high salt and low methanol concentrations help improve protein immobilization to the membrane during electrophoretic transfer, especially for proteins with higher molecular weights. Nitrocellulose membranes are not optimal for electrophoretic transfer of nucleic acids, as the high salt concentrations that are required for efficient binding will effectively elute some or all of the charged nucleic acid fragments.

Yes we can use different membrane instead if that make us meet the such requirements…

Can RNAi technique be used as a treatment of antibiotics resistance in Bacteria

Yes, it can be modified using this technology but we are still not sure it would be proved to be an efficient.. Bacteria often carry extrachromosomal genetic elements called plasmid which carry resistant genes…

Antibiotic resistance fall into the same manner but this resiatance is wide than our practical approach, i mean we have to discovera lot if genes and sequences which involve in this type of phenomena and according to that we should have to design various silencers to make our approach more effective which is gonna be really tough and incur a lot if research and money