Microbiologia Bacteriana

Sporulation in Bacillus subtilis

Antibody Immune Response

Alpha-Hemolysin: A Protein That Kills

How the Body Works : How Bacteria Cause Disease

Hospital Acquired infections

 

Nosocomial infection - MRSA Infection

Hospital acquired infections - Nosocomial infection

An infection acquired in a hospital. Specifically an infection that was not present or incubating prior to the patient being admitted to the hospital, but occurred within 72 hours after admittance to the hospital.

Medical School Pathology

Scopulariopsis

Found in house dust, old carpeting, fruits and nuts, and other materials. This organism is able to decompose arsenic compounds. It may grow on wallpaper containing paris green, producing arsine gas.


 Anti-static compounds containing arsenic are used in some wall-to-wall carpeting, which may result in high concentrations of Scopulariopsis. It may cause infections of the skin and nails.

Human Disease : Stages of disease

The Diseases Database is a cross-referenced index of human disease, medications, symptoms, signs, abnormal investigation findings etc. This site provides a medical textbook-like index and search portal covering areas including

• Internal medical disorders
• Symptoms and signs
• Congenital and inherited disorders
• Infectious diseases and organisms
• Drugs and medications
• Common haematology and biochemistry investigation abnormalities

Identification of Medically Important Fungi.

Identification of Zygomycetes.

Subcutaneous zygomycosis is generally caused by traumatic implantation and lesions vary considerably,
but include plaques, pustules, ulcerations, deep abscesses and ragged necrotic patches. In the
immunocompetent host, lesions usually remain localised around the site of inoculation and generally
respond well to local debridement and Amphotericin B treatment. However, in the debilitated patient,
zygomycosis is the most acute and fulminate fungal infection known.

 The disease typically involves therhino-facial-cranial area, lungs, gastrointestinal tract, skin, or less commonly other organ systems. It isoften associated with acidosis diabetes, malnourished children, severely burned patients and otherdiseases such as leukemia and lymphoma, immunosuppressive therapy, or use of cytotoxins and corticosteroids.

The infecting fungi have a predilection for invading vessels of the arterial system, causing embolization and subsequent necrosis of surrounding tissue.


Two orders, the Mucorales and the Entomophthorales contain genera and species of medical
importance. In general, fungi in the order Mucorales cause the more severe forms of disease with most
species belonging to the genera Rhizopus, Absidia, Rhizomucor, Mucor and Apophysomyces.
Rhizopus oryzae is the most frequent infectious agent reported, followed by R. microsporus var.
rhizopodiformis, Absidia corymbifera and Rhizomucor pusillus. These four species account for more
than 80% of culture proven cases of zygomycosis. Other mucoraceous species reported less frequently
include R. microsporus var. microsporus, Mucor ramosisimus, M. circinelloides, M. indicus,
Apophysomyces elegans, Cunninghamella bertholletiae and Saksenaea vasiformis. Basidiobolus
ranarum and Conidiobolus coronatus are the principle species of the Entomophthorales that cause
human disease, predominantly of the nasal mucosa and subcutaneous tissue.

Key features for identification include:
·  Coenocytic, mostly non-septate hyphae.
·  Zygospore morphology in homothallic strains, however most isolates are heterothallic, ie zygospores
are absent, therefore identification is based primarily on sporangial morphology. This includes the
following:

1. Arrangement and number of sporangiospores.
2. Sporangial shape and colour.
3. Presence or absence of columellae and apophyses.
5. Presence or absence of rhizoids
.
·  Growth temperature studies are also useful ie 35, 40, 45OC.
·  Tease mounts are best, use a drop of 95% alcohol as a wetting agent to reduce air bubbles.
·  May need to induce sporulation in isolates of Saksenaea vasiformis and Apophysomyces elegans
by using Czapek-dox agar or water agar.

Human Disease Caused By Fungi & Protists

Identification of Medically Important Fungi

Separation of taxa is still primarily based on the method of spore production of the perfect or sexual state (teleomorph) and three major subdivisions, the Zygomycetes, Ascomycetes and Basidiomycetes are generally recognized. However for medical mycologists two other groups are of particular importance; the yeasts and the hyphomycetes or conidial moulds.

Select from one of the following groups:
Dermatophytes
Yeasts
Dimorphic Pathogens
Hyphomycetes (hyaline moulds)
Hyphomycetes (dematiaceous moulds)
Coelomycetes
Zygomycetes
Oomycota
Basidiomycetes

Candidiasis

Candidiasis is a primary or secondary mycotic infection caused by members of the genus Candida. The clinical manifestations may be acute, subacute or chronic to episodic. Involvement may be localized to the mouth, throat, skin, scalp, vagina, fingers, nails, bronchi, lungs, or the gastrointestinal tract, or become systemic as in septicemia, endocarditis and meningitis.

In healthy individuals, Candida infections are usually due to impaired epithelial barrier functions and occur in all age groups, but are most common in the newborn and the elderly. They usually remain superficial and respond readily to treatment. Systemic candidiasis is usually seen in patients with cell-mediated immune deficiency, and those receiving aggressive cancer treatment, immunosuppression, or transplantation therapy.



Thrush Symptoms

Symptoms of Candidiasis

Microbial agents of disease : Fungi & Protozoa

FUNGAL DISEASE

Fungal diseases are called mycoses and those affecting humans can be divided into four groups based on the level of penetration into the body tissues:

Superficial mycoses are caused by fungi that grow only on the surface of the skin or hair.
Cutaneous mycoses or dermatomycoses include such infections as athlete's foot and ringworm, in which growth occurs only in the superficial layers of skin, nails, or hair.
Subcutaneous mycoses penetrate below the skin to involve the subcutaneous, connective, and bone tissue.
Systemic or deep mycoses are able to infect internal organs and become widely disseminated throughout the body. This type is often fatal.
The most common type of subcutaneous mycosis seen worldwide is sporotrichosis, which occurs most often in gardeners and farmers who come in direct contact with soil. This is a chronic infection caused by the fungus Sporothrix schenckii, occurring in three forms. The 'cutaneous lymphatic form' is characterized by a single pustule or nodule that forms at the site of invasion. This is followed by lymphatic spread and the development of numerous subcutaneous lesions. This 'disseminated form' is marked by multiple, painless cutaneous or subcutaneous nodules, which can form into ulcers or abscesses involving the muscles, joints, bones, eyes, gastrointestinal system, mucous membranes, and nervous system. The 'pulmonary form' results from the inhalation of spores, but produces much the same forms of the disease.

Other forms of subcutaneous mycoses occur mostly in the tropics and subtropics and are caused by several fungal species. These conditions are called chromomycosis (producing wartlike nodules that can ulcerate) and maduromycosis (or mycetoma -- a chronic slowly progressive destructive infection involving several layers of skin, producing abscessing granulomas). Treatment is difficult and often requires surgical removal of the offending tissues.

Hepatitis

Hepatitis implies injury to the liver characterized by the presence of inflammatory cells in the tissue of the organ. The name is from ancient Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation" (c. 1727).

The condition can be self-limiting, healing on its own, or can progress to scarring of the liver. Hepatitis is acute when it lasts less than six months and chronic when it persists longer.


A group of viruses known as the hepatitis viruses cause most cases of liver damage worldwide. Hepatitis can also be due to toxins (notably alcohol), other infections or from autoimmune
process.

It may run a subclinical course when the affected person may not feel ill. The patient becomes unwell and symptomatic when the disease impairs liver functions that include, among other things, removal of harmful substances, regulation of blood composition, and production of bile to help digestion.

swine flu virus

Swine influenza (also called swine flu, hog flu, pig flu and sometimes, the swine) is an infection by any one of several types of swine influenza virus.

Swine influenza virus (SIV) is any strain of the influenza family of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3.

Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human influenza, often resulting only in the production of antibodies in the blood.

If transmission does cause human influenza, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection. The meat of an infected animal poses no risk of infection when properly cooked.

During the mid-20th century, identification of influenza subtypes became possible, allowing accurate diagnosis of transmission to humans. Since then, only 50 such transmissions have been confirmed. These strains of swine flu rarely pass from human to human.

Symptoms of zoonotic swine flu in humans are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort.

Malaria

Symptoms of malaria include fever, shivering, arthralgia (joint pain), vomiting, anemia (caused by hemolysis), hemoglobinuria, retinal damage, and convulsions. The classic symptom of malaria is cyclical occurrence of sudden coldness followed by rigor and then fever and sweating lasting four to six hours, occurring every two days in P. vivax and P. ovale infections, while every three for P. malariae. P. falciparum can have recurrent fever every 36–48 hours or a less pronounced and almost continuous fever.

For reasons that are poorly understood, but that may be related to high intracranial pressure, children with malaria frequently exhibit abnormal posturing, a sign indicating severe brain damage. Malaria has been found to cause cognitive impairments, especially in children.

It causes widespread anemia during a period of rapid brain development and also direct brain damage. This neurologic damage results from cerebral malaria to which children are more vulnerable. Cerebral malaria is associated with retinal whitening, which may be a useful clinical sign in distinguishing malaria from other causes of fever

malaria lifecycle

Malaria is a vector-borne infectious disease caused by a eukaryotic protist of the genus Plasmodium. It is widespread in tropical and subtropical regions, including parts of the Americas, Asia, and Africa. Each year, there are approximately 350–500 million cases of malaria, killing between one and three million people, the majority of whom are young children in Sub-Saharan Africa.

Ninety percent of malaria-related deaths occur in Sub-Saharan Africa. Malaria is commonly associated with poverty, but is also a cause of poverty and a major hindrance to economic development.

Malaria is one of the most common infectious diseases and an enormous public health problem. Five species of the plasmodium parasite can infect humans; the most serious forms of the disease are caused by Plasmodium falciparum. Malaria caused by Plasmodium vivax, Plasmodium ovale and Plasmodium malariae causes milder disease in humans that is not generally fatal. A fifth species, Plasmodium knowlesi, causes malaria in macaques but can also infect humans. This group of human-pathogenic Plasmodium species is usually referred to as malaria parasites.

Usually, people get malaria by being bitten by an infective female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria, and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites an infected person, a small amount of blood is taken, which contains microscopic malaria parasites. About one week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito's saliva and are injected into the person being bitten.

The parasites multiply within red blood cells, causing symptoms that include symptoms of anemia (light-headedness, shortness of breath, tachycardia, etc.), as well as other general symptoms such as fever, chills, nausea, flu-like illness, and, in severe cases, coma, and death. Malaria transmission can be reduced by preventing mosquito bites with mosquito nets and insect repellents, or by mosquito control measures such as spraying insecticides inside houses and draining standing water where mosquitoes lay their eggs. Work has been done on malaria vaccines with limited success and more exotic controls, such as genetic manipulation of mosquitoes to make them resistant to the parasite have also been considere

What is Probiotic

Probiotic is opposite of antibiotic. The word anti (against) & bio (life) literally means "against life" and probiotic means "for life".

Probiotics

Brain, Hyptothalamus, Pituitary Gland, Endocrine System

30 Years of Biochemistry and Beyond

HIV LIFECYCLE