INFECTION: A human with an infection has another organism inside them which gets its sustenance (nourishment) from that person; it colonizes that person and reproduces inside them. The human with that organism (germ) inside is called the host, while the germ or pathogen is referred to as a parasitic organism. Another name for an organism that causes infection is an infectious agent. It is only an infection if the colonization harms the host. It uses the host to feed on and multiply at the expense of the host to such an extent that his/her health is affected. The normal growth of the bacterial flora in the intestine is not an infection, because the bacteria are not harming the host. An organism which colonizes and harms a host's health is often called a pathogen. Examples include: Fungi made up of brands of hair like structure called hypea Bacteria: made of single cell with no nucleus. Prions: made of protein Virus: infectious agent a piece of Nucleic acid coated with protein. VIRAL INFECTIONS Infections caused by a virus. An individual may become infect by: Inhaling the virus (breathing it in) Being bitten by infected insects or parasites Through sexual contact Respiratory infections of the upper airways, nose and throat are the most common forms of viral infections. Some antiviral medications may help, they either undermine the
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INFECTION:
A human with an infection has another organism inside them which gets its sustenance (nourishment) from that person; it colonizes that person and reproduces inside them. The human with that organism (germ) inside is called the host, while the germ or pathogen is referred to as a parasitic organism. Another name for an organism that causes infection is an infectious agent.
It is only an infection if the colonization harms the host. It uses the host to feed on and multiply at the expense of the host to such an extent that his/her health is affected. The normal growth of the bacterial flora in the intestine is not an infection, because the bacteria are not harming the host.
An organism which colonizes and harms a host's health is often called a pathogen. Examples include:
Fungi made up of brands of hair like structure called hypea Bacteria: made of single cell with no nucleus. Prions: made of protein Virus: infectious agent a piece of Nucleic acid coated with protein.
VIRAL INFECTIONS
Infections caused by a virus. An individual may become infect by:
Inhaling the virus (breathing it in) Being bitten by infected insects or parasites Through sexual contact
Respiratory infections of the upper airways, nose and throat are the most common forms of viral infections.
Some antiviral medications may help, they either undermine the virus' ability to reproduce, or boost the patient's immune system.
Viruses are tiny organisms, much smaller than bacteria or fungi. The virus invades its host and attaches to a cell, entering it and releasing genetic material (DNA or RNA). This genetic material helps the virus multiply; it takes over control of the cell, making it replicate the virus. A cell that has this genetic material inserted into it cannot function properly and soon dies. When it does it releases new viruses, which infect new cells, etc.
Not all viruses destroy their host cell. Some of them just alter what the cell does. Experts say that some cells become cancerous as a result of a virus interfering with its functions.
Sometimes the genetic material lies dormant in a cell; some time in the future something triggers the cell and the virus starts multiplying again, making the host ill.
Viruses target specific cells in the body, such as those in the genitals or upper respiratory tract. Some target certain age groups, such as babies or young children, such as those that cause croup. (Croup is a common respiratory condition characterized by inflammation of the upper airways that often occurs in infants and children. The result is a swelling and narrowing of the larynx (voice box) and trachea (wind pipe) that results in a harsh, barking cough)
The rabies virus targets the cells in the host's nervous system. Viruses may target skin cells and cause warts. (Rabies is a deadly virus that attacks the CNS (central nervous system) It is transmitted from animals to humans (zoonotic), most commonly by animal bites - although, there have been cases of humans becoming infected in bat caves after breathing in the air. Rabies infection is nearly always fatal unless prompt treatment is administered before symptoms begin.
Infected people who do not receive post-exposure prophylaxis (preventative treatment after being exposed to the virus) will experience fever, myalgia (muscle pains) and headache, which eventually progresses to brain inflammation, confusion, paralysis, coma and death.)
(Warts are skin growths which are caused by the human papillomavirus (HPV) - they are non-cancerous. The virus causes keratin, a hard protein in the epidermis (the top layer of the skin) to grow too fast. Warts are different from moles. While moles are dark and can be quite large, warts tend to be small, skin-colored rough lumps. Warts most commonly appear on a person's hands and feet.)
However, some viral infections can be systemic - they affect many different parts of the body, causing for example runny nose, sinus congestion, cough, and body aches.
BACTERIAL INFECTIONS
Bacteria are tiny single-cell microorganisms, usually a few micrometers in length that normally exist together in millions - they are neither plants nor animals - they belong to a group all by themselves. A gram of soil typically contains about 40 million bacterial cells. A milliliter of fresh water usually holds about one million bacterial cells.
Planet Earth is estimated to hold at least 5 nonillion bacteria. Scientists say that much of Earth's biomass is made up of bacteria. 5 nonillion = 5,000,000,000,000,000,000,000,000,000,000 (or 5x1030).
Spherical (like a ball) These are usually the simplest ones. Bacteria shaped like this are called cocci (singular coccus).<.li>
Rod shapedThese are known as bacilli (singular bacillus).Some of the rod-shaped bacteria are curved; these are known as vibrio. <.li>
SpiralThese known are as spirilla (singular spirillus). If their coil is very tight they are known as spirochetes. <.li>
A bacterial cell differs somewhat from the cell of a plant or animal. Bacterial cells have no nucleus and other organelles (sub-units within a cell with a specific function) bound by a membrane, except for ribosome(Ribosomes are the components of cells that make proteins from amino acids.). Bacteria have pili, flagella, and a cell capsule (most of them), unlike animal or plant cells. An organism without a nucleus is called a prokaryote.
Bacteria can live in virtually any kind of environment, from extremely hot to super cold, some even in radioactive waste. A number of bacteria live in our bodies, on our skin, airway, mouth, digestive and urinary tracts - most of the time without causing any harm to the host.
A relatively small number of bacteria causes diseases in humans. Some of the most deadly diseases and devastating epidemics in human history have been caused by bacteria, including:
Cholera: an acute intestinal infection caused by ingestion of contaminated water or food Diphtheria: A highly infectious disease of the upper respiratory tract characterised by a sore
throat, fever and causing difficulty in breathing Dysentery: an infection of the intestines marked by severe diarrhea Plague: a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and
accidentally transmitted to humans by the bite of a flea that has bitten an infected animal Pneumonia: respiratory disease characterized by inflammation of the lung parenchyma
(excluding the bronchi) with congestion caused by viruses or bacteria or irritants Tuberculosis: Tuberculosis (TB) is an infectious disease that is caused by a bacterium called
Mycobacterium tuberculosis. TB primarily affects the lungs, but it can also affect organs in the central nervous system, lymphatic system, and circulatory system among others. The disease was called "consumption" in the past because of the way it would consume from within anyone who became infected.
Typhoid: Typhoid fever is an infectious disease caused by the bacteria Salmonella typhi. It is also known as enteric fever, or commonly just typhoid. Typhoid fever and paratyphoid fever
are clinically indistinguishable diseases, collectively called enteric fever. It easily spreads through contaminated food and water supplies and close contact with others who are infected. The illness is characterized by very high fever, sweating, and diarrhea.
Bacterial infections typically present with localized redness and heat, inflammation (swelling) and pain. Bacterial infections tend to present localized pain more frequently than viral infections (not always). Even with a throat infection, a bacterial one will usually have more severe pain on one side of the throat. If there is pain in just one ear, it is more likely to be a bacterial infection.
Mycosis (fungal infection/disease)
Mycosis is a fungal infection in or on a part of the body, or a disease caused by a fungus. Some fungi reproduce through very small airborne spores which people either inhale or pick up on their skin - i.e. must fungal infections start in the lungs or the skin.
Patients on long-term strong antibiotics are at higher-than-normal risk of developing a fungal infection. Strong antibiotics can eventually reduce the population of good bacteria which help maintain the balance of microorganisms in the intestines, mouth, vagina and other parts of the body. If enough of these good bacteria are destroyed, the fungi have an opportunity to grow and cause health problems for the host.
Patients with weakened immune systems, such as those with HIV/AIDS and individuals receiving chemotherapy have a higher risk of developing a fungal infection. Diabetes patients, especially those who do not have good disease control are also more susceptible.
There are three types of fungal infections of the skin:
Superficial mycoses - limited to the surface of the skin and hair, such as Tinea versicolor, which commonly affects young people. The chest, back, upper arms or legs may be affected (very rarely the face). Light or reddish-brown spots appear on the skin. Sometimes the spots are not visible.
Cutaneous mycoses - occurs deeper in the skin, in the epidermis. The hair and nails may also be affected. Cutaneous mycoses are limited to the keratinized layers of skin, nails and hair. This type of mycosis is caused by dermatophytes(a group of three types of fungus that commonly causes skin disease in animals and humans), which may cause ringworm.
Subcutaneous mycoses - these types of infections go deeper into the skin, including the dermis, subcutaneous tissue, as well as muscle and fascia. The fascia is a band of tissue below the skin that covers underlying tissues - it separates different tissue layers and surrounds muscles. Subcutaneous mycoses tend to be long term (chronic) and are usually caused by skin penetration.
A prion is an infectious agent consisting mainly of protein - it contains no genetic material. It is neither bacterial nor fungal. It occurs normally in a harmless form, but when it folds into an abnormal shape it turns into a rogue agent and affects the structure of the brain or other parts of the nervous system. All forms of prion infections are currently untreatable and fatal.
Prions cause degenerative brain diseases, such as mad cow disease.
Prion diseases, also called transmissible spongiform encephalopathies, are brain wasting diseases that affect humans and animals. Made primarily of protein, prions are small active agents that act a bit like viruses: they don't replicate themselves but hijack material in the host and cause it to behave abnormally, for instance they force host proteins to fold into shapes that clump together into plaques that clog up the brain, causing it gradually to waste away.
A team of scientists from the US and the UK have found a new type of prion disease in mice that damages brain arteries and may help us better understand and treat types of Alzheimer's disease that cause similar damage.
Antibiotics by class
Generic name Brand names Common uses Possible side effects
AMINOGLYCOSIDES
Amikacin Amikin
Infections caused by Gram-negative bacteria, such as Escherichia coli
Hearing loss
Dizziness
Kidney damage
Gentamicin Garamycin
Kanamycin Kantrex
Neomycin Mycifradin
Netilmicin Netromycin
Tobramycin Nebcin
Paromomycin Humatin
CARBACEPHEM
Loracarbef Lorabid
CARBAPENEMS
Ertapenem Invanz
Bactericidal for both Gram-positive and Gram-negative organisms and therefore useful for empiric broad-spectrum antibacterial coverage
Gastrointestinal upset
and diarrhea
Nausea
Seizures
Headache
Rash and allergic
reactions
Doripenem Doribax
Imipenem/Cilastatin Primaxin
Meropenem Merrem
CEPHALOSPORINS (FIRST GENERATION)
Cefadroxil Duricef Gastrointestinal upset
and diarrhea
Nausea (if alcohol taken
concurrently)
Allergic reactions
Cefazolin Ancef
Cefalotin or Cefalothin Keflin
Cefalexin Keflex
CEPHALOSPORINS (SECOND GENERATION)
Cefaclor Ceclor
Gastrointestinal upset
and diarrhea
Nausea (if alcohol taken
concurrently)
Allergic reactions
.
Cefamandole Mandol
Cefoxitin Mefoxin
Cefprozil Cefzil
Cefuroxime Ceftin, Zinnat
CEPHALOSPORINS (THIRD GENERATION)
Cefixime Suprax Gastrointestinal upset
and diarrhea
Nausea (if alcohol taken
concurrently)
Allergic reactions
CefdinirOmnicef, Cefdiel
Cefditoren Spectracef
Cefoperazone Cefobid
Cefotaxime Claforan
Cefpodoxime Vantin
Ceftazidime Fortaz
Ceftibuten Cedax
Ceftizoxime Cefizox
Ceftriaxone Rocephin
CEPHALOSPORINS (FOURTH GENERATION)
Cefepime Maxipime
Gastrointestinal upset
and diarrhea
Nausea (if alcohol taken
concurrently)
Allergic reactions
CEPHALOSPORINS (FIFTH GENERATION)
Ceftobiprole Used to treat MRSA
Gastrointestinal upset
and diarrhea
Nausea (if alcohol taken
concurrently)
Allergic reactions
GLYCOPEPTIDES
Teicoplanin Targocid
Vancomycin Vancocin
Telavancin Vibativ
LINCOSAMIDES
Clindamycin Cleocin Serious infections in penicillin-allergic patients; clindamycin topically for acneLincomycin Lincocin
acnerickettsial infections, *malaria *Note: Malaria is caused by a protist and not a bacterium.
Potential toxicity to mother and
fetus during pregnancy
Enamel hypoplasia (staining of
Minocycline Minocin
Oxytetracycline Terramycin
TetracyclineSumycin,Achromycin V, Steclin
ANTIBIOTIC – MODE OF ACTION
Technically, an antibiotic is a substance that is produced by one microorganism and it is capable of killing or inhibit the growth of another microorganism which can a virus, bacteria, fungi, yeast, protozoan or any other pathogen.
The first antibiotic that was developed was Penicillin, a biological compound that is produced by fungi in the genus Penicillium. It was discovered by Alexander Fleming in the year 1928. After that, several other types of antibiotics produced by different species of bacteria and fungi were isolated. Some of these include cephalosporins; aminoglycosides such as streptomycin, gentamicin and kanamycin; ansamycins such as geldanamycin and carabecephems; glycopeptides like vancomycin; macrolides like erythromycin and azithromycin, penicillin, quinolone, polypeptide and sulfonamide.
All these antibiotics have different mode of action by which they act as therapeutic agents. Some of the modes of action by different antibiotics are mentioned below:
Cell Wall Synthesis Inhibitors:
Bacteria contain murein or peptidoglycan that is highly essential in maintaining the cell wall structure. Cell wall synthesis inhibitors such as beta-lactams, cephalosporins and glycopeptides block the ability of microorganisms to synthesize their cell wall by inhibiting the synthesis of peptidoglycan.
Interfering with Protein Synthesis:
These classes of antibiotics inhibit the protein synthesis machinery in the cell. Some examples include tetracyclines, chloramphenicol, aminoglycosides and macrolides.
Cell Membrane Inhibitors :
Antibiotics such as polymyxins disrupt the integrity and structure of cell membranes, thereby killing them. These set of antibiotics are mostly effective on gram negative bacteria because these are the bacteria that contain a definite cell membrane.
Effect on Nucleic Acids:
DNA and RNA are extremely essential nucleic acids present in every living cell. Antibiotics such as quinolones and rifamycins bind to the proteins that are required for the processing of DNA and RNA, thus blocking their synthesis and thereby affecting the growth of the cells.
Competitive Inhibitors:
Also referred to as anti-metabolites or growth factor analog, these are antibiotics that competitively inhibit the important metabolic pathways occurring inside the bacterial cell. Important ones in this class are sulfonamides such as Gantrisin and Trimethoprim.
HYPERTENSION AND ANTIHYPERTENSIVES
Antihypertensive are used to restore blood pressure (BP) in normal cases of hypertension. This
class of drugs includes a large number of substances with diverse modes of action. When one
drug is not sufficient to normalize blood pressure, two antihypertensive agents may be involved.
Blood pressure is the pressure exerted by blood in blood vessels, it is naturally regulated at
different levels including renal, hormonal and nervous. This pressure varies depending on the
rhythm of the heart. Represented by two digits (eg 140 / 80), represents the first blood pressure
(BP) ie maximum blood pressure when the heart contracts (systole), the second blood pressure
minimum prevailing in when the rest of the heart (diastole).
Except in severe cases, hypertension is a chronic disease more or less silent whose effects are
observed after several years. It is therefore important to detect and treat. Treatment of
hypertension is almost always introduced to life.
Side effects:
According to their mode of action, anti-hypertensives can have different side effects and may
interact with other substances. The side effects common to all is hypotension that is to say
excessive reduction of blood pressure. This is particularly evident in the transition from sitting to
standing position, this is called orthostatic hypotension. A reduction in dosage is usually
sufficient to eliminate this side effect. The combination with other medicines that lower blood
pressure may also cause hypotension.
The major classes of drugs:
The alpha1 blockers
By blocking certain receptors in the adrenergic system (called receptors alpha1-adrenergic
receptors), these drugs cause dilation of blood vessels and thus a decrease in blood pressure. Less
and less used, they are indicated in young patients with a history of depression, asthma, chronic
bronchitis, diabetes. In short, when other classes of antihypertensives are more or less cons-
listed. Their main side effects are orthostatic hypotension may result in loss of consciousness,
fluid retention synonymous with edema.
The central anti-hypertensive
Their action is exerted mainly by stimulation of alpha2 adrenergic receptors. Unlike the alpha1-
adrenergic receptors including inhibition lowers blood pressure, alpha2 receptors decreases
blood pressure when stimulated. They are primarily prescribed for hypertension difficult to
control. Side effects are sedation, constipation, dry mouth, depression. They are used in elderly
patients suffering from hypertension complicated by kidney failure, asthma or diabetes.
Beta-blockers
These drugs work by blocking receptors involved in the increase of blood pressure: the beta-
adrenergic receptors. They are mainly used in uncomplicated hypertension in young patients.
They are cons-indicated in cases of asthma, Raynaud's syndrome, heart failure and certain
disorders of cardiac conduction (atrioventricular block) and arteritis, etc.. Their main side effects
include depression, impaired libido, Nightmares and fatigue.
Calcium channel blockers
They work by blocking crossing patterns of calcium in cells. The decrease in cellular calcium
that results causes a relaxation of arteries, decreased activity of the heart and thus a decrease in
blood pressure. It is a class of antihypertensive quite heterogeneous. They are targeted primarily
to elderly patients, the coronary, diabetes, obesity ... They are also useful during severe
hypertension or poorly controlled by beta blockers, or secondary to primary aldosteronism, or
associated with impotence, hyperlipidemia.
Thiazide diuretics (kaliuretic)
They increase the natural process of removing water by the kidneys that lowers blood volume
and made a drop in blood pressure. The main side effects are decreases in blood potassium
(potentially very serious), glucose, cholesterol or uric acid (gout), orthostatic hypotension. They
are widely used. They are more efficient than the subject is older and retain a very important role
in the treatment of hypertension.
Sparing diuretics
Like its predecessors, they promote the renal elimination of water but by a different mechanism..
They facilitate renal excretion of sodium (in favor of potassium) and water, which promotes a
decrease in blood volume and blood pressure. Depending on the products, their side effects
slightly different but they share the risk of increased blood levels of potassium (potentially very
serious). Other effects of hormonal disorders resulting in such a volume increase of the breast,
impotence or menstrual disorders, digestive problems or headaches.
Inhibitors of angiotensin converting enzyme or AEC
As their name implies, they block an enzyme converting enzyme. This naturally involved in the
formation of vasoconstrictor compounds (ie, that constrict the blood vessels) as angiotensin II.
Blocking this enzyme limits the production of these compounds and allows a reduction in blood
pressure. They may result from other dry cough, headache, taste disorders or digestive. They are
cons-indicated in pregnancy or lactation but also in case of allergies, pregnancy and lactation,
stenosis of the renal artery.
Inhibitors of angiotensin II
Unlike ACE inhibitors, these drugs do not prevent the formation of angiotensin II, but its action.
Now angiotensin II is essentially the most known hypertensive. This class of antihypertensives is
the last appeared. They can cause headaches and dizziness.
The associations of antihypertensive
They are often used because they reduce the dosage of each drug used and therefore their
respective side effects. In some cases even the side effects are opposed, for example, in
associations of both classes of diuretics for which the reduction and increase in blood potassium
vanish more or less. Given the number of anti-hypertensives, the possibilities are endless
Association and have more or less side effects, indications and cons of each component.