Herpes viruses Summarized - Part I

Namaste!

Today in Virology, we are discussing one of the most common and widespread clan of viruses i.e. Herpesviruses. Since this is a major topic, we will discuss this in two separate parts. Also, as this is only a summary, I will only talk about the major, key points.

Lets dive!

Differentiate between H and O antigen of Salmonella and how to remember it!

Ssup people.
Staph here.
Today we will have a look at differences between two famous antigens of Salmonella.
So without wasting any time, let's get straight into it.
Yeah, thanks. As if I was gonna get gay into it.
-_-
Ignore.
Let's start.

Hemolytic disease of the Newborn

Hello there,

My name is Staph and today we will be learning how to twerk.

...

...

Can you write a single post without getting grilled by me -_-

Na, absolutely not. Anyways today we will be learning about monkeys and their effects on our lives. And monkeys do twerk, so it's somewhat related to the post ;p

Back to the subject

I know many of you might be knowing about Rh blood group inherited by our ancestral recess monkeys.

Jesus! It's Rhesus. Rhesus monkeys.

Sorry, it's recess time when I am writing my post. Kinda hungry.

Off topic.

So Rh blood group is considered to be second most important after ABO. Talking about the disease, HDN occurs when the mother is Rh negative and the fetus is Rh positive.

Let's look at it in detail.

There is a mother who is Rh negative, carrying a fetus who is Rh positive. Fetal blood cells rarely gets into the blood circulation system of the mother. But chances increase during delivery. This is when the fetal blood cells gain entry into mother's system. Due to this, the mother gets sensitized and produces antibodies against the Rh blood cells. As this sensitization occurs after the delivery, the first child is born without any harm. Difficulties occurs during the second and the subsequent pregnancies. Rh antibodies have structure similar to Ig antibodies and hence they are incomplete antibodies. Therefore, it can pass from mother to fetus by crossing the placental membrane and damage it's erythrocytes.

The clinical features can very from severe jaundice in the newborn to erythroblastosis fetalis or intrauterine death. Though the HDN is very harmful disease, it's occurrence is very less than expected.

 There are some factors that influence the incidence of hemolytic disease due to the Rh incompatibility. They are as follows:

1. Immunological unresponsiveness to the Rh antigen: I guess it's pretty clear by the name. Some individuals are nonresponders and never respond to the Rh antigens even after getting eposed to it. So they never generate antibodies against it and hence the fetus is not harmed.
2. Fetomaternal ABO incompatibility: So as iron cuts iron and poison kills poison, here incompatibility nullifies incompatibility. If the mother and fetus have ABO incompatibility, the Rh incompatibility becomes ineffective. This is because the fetal cells entering the maternal circulation are destroyed rapidly by the ABO antibodies before they can induce Rh antibodies.
3. Number of Pregnancies: Number of pregnacy matters, because the first child mostly escapes the harmful effects. The risk to infant occurs with the successive pregnancies.
4. Zygosity of the father: An individual can be homozygous or heterozygous with respect to the D antigen. If the father is homozygous all his children will be Rh positive, whereas if he is heterozygous only half of his children will be Rh positive.

I hope this explanation helps you all.

Lots of love and a high six.

-Staph :D

Blood grouping - ABO system

Hello to all my learning group. 

Today we will be learning blood grouping by ABO system.  We all know this system and the antigens, antibodies present on it. But if I ask you suddenly which is the antigen and antibody present in group A, you won't be able to tell it instantly, unless you are a unicorn. 

What?? 

Yes unicorns are magical so they can do anything. Trust me. 

I am just kidding. But on a serious note even after knowing the answers correctly I could never answer them on the spot, thanks to dear ADHD. 

So I made myself a simpler way to remember them and I am today sharing it with you guys.

Here's my way to remember it. Let's go

It is known that there are four blood groups in this system. A, B, AB and O. 

Now have a look at the word antigen.  Here 'gen' can be understood as general.  General generally means 'the same'So when I ask you what is the antigen on group A, then the answer is same. A. For blood Group B it's B. For AB its A and B. Capital O has an anatomy similar to 0 and hence it has 0 antigens.

Now similarly have a look at the word antibody. Here 'body' can be understood as a person's body.  Every person have different kinds of body and it is 'never the same' . 

Hence when I ask you what is the antibody present on group A the should be not same. And therefore the answer is B. For blood group B, the answer is A. For the blood group AB its 0 and for O it's A and B.

I hope all my confused pals find this helpful 

Here's our signature high six. 

Lots of love 

-Staph. 

Difference between Exotoxin and Endotoxin

Hello Everyone, 

Today I will be writing about Some important points to differentiate Exotoxin and Endotoxin

Toxins are substances created by plants and animals that are poisonous to humans. Toxins also include medications that are helpful in small doses, but poisonous when used in large amounts. Most toxins that cause problems in humans are released by germs such as bacteria. For example,cholera is due to a bacterial toxin. Other toxins that cause problems include metals, such as lead, and organic chemicals in the environment. 

Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their severity, ranging from usually minor (such as a bee sting) to almost immediately deadly (such as botulinum toxin).

These are not the most common forms of pathogenic bacteria, however. More common are the toxin producing varieties. There are two types of toxins made by bacteria, exotoxins and endotoxins. The differentiating points are mentioned below

-Dixy

River's postulate

Hello Everyone,
Today I will be talking about River's Postulate.

Diseases at one time were thought to be caused by wrath of the gods, configuration of stars or miasmas. After a real struggle that occurred not so many years ago, certain maladies were shown to be induced either by small animals or minute plants, e.g., protozoa, fungi, bacteria and spirochetes. Indeed, the victory was so great that most workers in time began to consider that all infectious diseases, including those whose incitants had not been discovered, must be caused by agents similar to those already recognized.

In my previous post I have mentioned about  Koch's postulates.
In order to prove an infectious etiology for a disease Koch’s postulates require that one isolate a bacterium from a diseased animal or plant and when reintroduced it causes the same disease. Rivers’ postulates basically require the same for viral diseases.

However virus detection is not straight forward and proper identification has a bearing on relating a particular virus to particular disease. In classical sense, Koch’s postulates can not be applied to viral disease because unlike bacterial cells, viruses cannot be cultivated in pure cultures. to overcome circumvent this problem Thomas M River in 1937 expanded Koch’s postulates to include viruses as follows:

•  Filtrates of infectious material shown not to contain bacterial or other cultivable organisms must produce the disease or it's counterpart ,
• or filtrates must produce certain Antibodies in appropriate animals.

This is known to as River's Postulate.

It is obvious that Koch's postulates have not been satisfied in viral diseases. Moreover, it is equally evident that proof of the etiological significance of viruses has been obtained without their satisfaction. Such a statement, however, does not imply that certain conditions do not have to be met before the specific relation of a virus to a disease is established. The conditions are:
 (a) A specific virus must be found associated with a disease with a degree of regularity.

(b) The virus must be shown to occur in the sick individual not as an incidental or accidental finding but as the cause of the disease under investigation.

Nevertheless, there are certain differences. In the first place, it is not obligatory to demonstrate the presence of a virus in every case of the disease produced by it. Secondly, the existence of virus carriers is recognized. Finally, it is not essential that a virus be grown on lifeless media or in modified tissue cultures.

Thank you,
with love
-Dixy

Chicken Pox

Hello Everyone ,

Today I will be discussing about Chicken Pox , I had already talked about Chicken Pox in one of My post "Is It really funny "which talks about what funny answer expected when asked about them .

Do not get confused, Chicken pox does not have any relationship with neither Chicken nor Pox virus. this post may have answer to all your questions.

Chickenpox (varicella), a viral illness characterised by a very itchy red rash, is one of the most common infectious diseases of childhood. It is usually mild in children but there is a risk of serious complications, such as bacterial pneumonia.It is characterized by a generalized vesicular eruption of skin and mucus membranes.


ETIOLOGY :
Varicella zoster virus causes varicella (chickenpox).  It is known by many names, including chickenpox virus, varicella virus, zoster virus, and human herpesvirus type 3 (HHV-3).This Virus ( linear dsDNA )viruses,belongs to Family of Herpes Viridae .It produces 6 Glycoproteins (gB, gC, gE, gH, gI, gK, gL) which help the virus to attach to respiratory epithilial.

MODE OF TRANSMISSION:
Air borne and humans are reservoir for virus inhalation . It is Highly Contagious . It is spread by droplets from a sneeze or cough, or by contact with the clothing, bed linens or oozing blisters of an infected person. 

PATHOGENISIS:

• Gains entry via Inhalation of Contaminated droplets nuclei and attaches to respiratory tract.
• It inhibits MHC molecule Recognision.
• The virus can spread rapidly to the face , upper trunk and then all over body via blood

The course of infection is as follow
0 day - virus attaches to Mucus membrane of respiratory tract

4-6th day-primary viramia in blood stream , further viral replication occur in liver and spleen. finally secondary viramia.

10th day-Infection of skin occurs and appearance of vesicles

SYMPTOMS:

Typical vesicular skin regions or rashes occur following incubation period of 10-20 days . these vesicles can be filled with pus and raptures and thus become covered with scabs. there is intense itching at this time.

LAB DIAGNOSIS:

• Varicella zoster  can be detected by IgM antibody by direct Fluorescence Antibody test.
• PCR
• Rise in IgG antibody titre in serum

lab diagnosis is not normally required as it can be diagnosed Clinically.

PROPHYLAXIS:

Vaccines known as Vari Vax available.One time infection provides life time immuity.

General measures include isolation of patient

TREATMENT:

Most cases of chickenpox require little or no treatment beyond treating the symptoms.

Antiviral used is Zovirax/Valtrex, Acyclovir

Home Remedies for Treating Chicken Pox

Baking Soda Remedy

One thing, which most patients complain of, is the rash that occurs during chicken pox. It can be irritating and painful. In order to reduce the itch and the burning sensation, use baking soda. Dissolve 2 teaspoons of baking soda in a small bucket of water and sponge the person down with this solution. The baking soda helps to reduce the itching and the irritation caused by the rash.

Pure Honey

Often patients are worried about the scars that are left behind with chicken pox. By applying pure honey on the scabs, they are less likely to leave marks. Always use pure honey and gently apply the honey on the scabs.

Vitamin E Oil

Vitamin E is said to be a natural skin rejuvenator. It has excellent healing properties that allow the skin to repair itself. Apply or massage the surface of the skin with vitamin E oil after the scabs have started to fall off. This prevents the pustules from leaving unsightly marks on the surface of the skin. The skin will also feel less raw.

Vinegar

Alternately, you can add a few tablespoons of vinegar into your bath water before you take a bath. The vinegar is excellent for reducing skin irritation and burning.

Garlic

Eat plenty of garlic in your soups . If you can, take garlic pills, which help to fight off the infection and boost the immunity of the affected person.

With love -Dixy

Let the Microorganisms Begin ....

Hello everyone,

Our bodies are pretty amazing. Day after day, they work hard — digesting food, pumping blood and oxygen, sending signals from our brains and much more. But there is a group of tiny invaders that can make our bodies sick — they're called Microorganisms.

Have you ever wondered why you get sick?

 The answer is Microorganisms. Microorganisms are tiny organisms that make you feel sick and cause disease. We come in contact with millions of Microorganisms every day. There are different kinds of Microorganisms: bacteria, fungi, viruses, and protozoa.

Microorganisms are parasitic, which means they gobble up nutrients and energy from other organisms (like us). This process causes someone who has trouble fighting off the them to show symptoms of common infections like fevers, sniffles, rashes, coughing, vomiting, and diarrhea, just to name a few.

Now that we know Microorganisms cause sickness, how do you think they are spread? they spread by many ways, including three types of transmission (or passing of germs): direct, indirect, and airborne. 

Direct transmission means person-to-person contact occurs, and the Microorganisms are passed that way. 

Indirect means that someone spread Microorganisms onto an object and when the next person touched that object, the Microorganisms spread. Microorganisms can also travel through the air to move from one person to another.

With all these different ways for Microorganisms to be passed around, you might wonder if there's a way to avoid them from getting to you. While we can’t really avoid Microorganisms altogether, we can take care of ourselves by washing our hands and covering our mouths when sneezing, among other things. This helps reduce the spread .

with love 

-Dixy

Lepromatous leprosy

Heyo Microbiologists..

Anything which has a pro word in it, seems kinda fascinating to me :p

I will stop discussing pro before I go off topic.

So yes..

Causing pathogen - Mycobacterium leprae.

These organisms are slower than the slowest tortoise on the earth. The cells don't divide rapidly, thus rendering a lot of drugs ineffective in the disease.

It is a chronic granulomatous disease which primarily involves skin, but has tendency to infect any tissue of any organ.

Lepromatous leprosy: This occurs to the patients which have low resistance. The bacilli are seen in large numbers inside the lepra cells. The skin usually forms small nodules sort of which consists a the infected tissue where the pathogens harbor in large large numbers.

These nodules then ulcerate and cause secondary infection. From here, the bacilli like unrestrained terrorists move in different tissues and invade in nose, mouth and upper respiratory tract and are shed in nasal and oral secretions.

Certain internal organs like kidneys, eyes, testes and bones also get infected. Lepromatous leprosy is the most hazardous form of leprosy and the prognosis is poor. In fact, the lepromin test too shows negative results. 

The other types of leprosy, lepromin test and the diagnosis are still to come in the next posts.

Hope it helps

-Staph :D

Koch's Postulates

Hello everyone, 

Today I will be talking about one of the topics from Medical Microbiology ie Koch's Postulate

It was thought back something that induce a disease in a diseased person could transfer it to other person and microorganisms are responsible for disease,but definitive route was not known. Robert Koch gave the hope that concept of infectious disease was given experimental support.

In his early work he studied anthrax a disease of cattle's. By careful microscopy and using special stains Koch proved that bacteria responsible for disease was always present in blood of animals.

Koch's postulates were developed in the 19^th century as general guidelines to identify pathogens that could be isolated with the techniques of the day.

Four criteria that were established by Robert Koch to identify the causative agent of a particular disease, these include:

1. The microorganism or other pathogen must be present in all cases of the disease




2. The pathogen can be isolated from the diseased host and grown in pure culture




3. The pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal




4. The pathogen must be re-isolated from the new host and shown to be the same as the originally inoculated pathogen.

Koch postulate was monumental step in the study of infectious disease . The postulate not only provides the need for linking and cause of infectious disease but also showed the importance of laboratory culture of infectious agent.

 with love 

-Dixy