AKD-PDMM.png' alt='Multi Point Line Driver' title='Multi Point Line Driver' />Multi drug resistant tuberculosis Wikipedia. Multi drug resistant tuberculosis MDR TB is a form of tuberculosis TB infection caused by bacteria that are resistant to treatment with at least two of the most powerful first lineanti TB medications drugs, isoniazid and rifampin. Some forms of TB are also resistant to second line medications, and are called extensively drug resistant TB XDR TB. Tuberculosis is caused by infection with the bacteria Mycobacterium tuberculosis. Almost one in four people in the world are infected with TB bacteria. Only when the bacteria become active do people become ill with TB. Bacteria become active as a result of anything that can reduce the persons immunity, such as HIV, advancing age, diabetes or other immunocompromising illnesses. TB can usually be treated with a course of four standard, or first line, anti TB drugs i. However, beginning with the first antibiotic treatment for TB in 1. TB bacteria developed resistance to the standard drugs through genetic changes see mechanisms. Currently the majority of multidrug resistant cases of TB are due to one strain of TB bacteria called the Beijing lineage. Game For Samsung Galaxy Y S 5360 more. This process accelerates if incorrect or inadequate treatments are used, leading to the development and spread of multidrug resistant TB MDR TB. Incorrect or inadequate treatment may be due to use of the wrong medications, use of only one medication standard treatment is at least two drugs, not taking medication consistently or for the full treatment period treatment is required for several months. Treatment of MDR TB requires second line drugs i. Shaver hydraulic post driver for fence post, or wood fences. Pounds posts in for any kind of fence. Analog Devices offers a range of lens driver solutions for camera modules in camera phones, camera enabled handsets, DSCs, consumer entertainment, and computer imaging. Treatment schedules for MDR TB involving fluoroquinolones and aminoglycosides can run for 2 years, compared to the 6 months of first line drug treatment, and cost over 1. USD. 1. 0If these second line drugs are prescribed or taken incorrectly, further resistance can develop leading to XDR TB. Resistant strains of TB are already present in the population, so MDR TB can be directly transmitted from an infected person to an uninfected person. In this case a previously untreated person develops a new case of MDR TB. This is known as primary MDR TB, and is responsible for up to 7. Acquired MDR TB develops when a person with a non resistant strain of TB is treated inadequately, resulting in the development of antibiotic resistance in the TB bacteria infecting them. These people can in turn infect other people with MDR TB. MDR TB caused an estimated 4. TB cases and 2. 50,0. MDR TB accounts for 3. TB cases worldwide. Resistant forms of TB bacteria, either MDR TB or rifampin resistant TB, cause 3. TB cases and 2. 1 of previously treated TB cases. Globally, most MDR TB cases occur in South America, Southern Africa, India, China, and the former Soviet Union. Treatment of MDR TB requires treatment with second line drugs, usually four or more anti TB drugs for a minimum of 6 months, and possibly extending for 1. TB with which the patient has been infected. Under ideal program conditions, MDR TB cure rates can approach 7. Mechanism of drug resistanceeditThe TB bacteria has natural defenses against some drugs, and can acquire drug resistance through genetic mutations. The bacteria does not have the ability to transfer genes for resistance between organisms through plasmids see horizontal transfer. Some mechanisms of drug resistance include 1. Cell wall The cell wall of M. TB contains complex lipid molecules which act as a barrier to stop drugs from entering the cell. Drug modifying inactivating enzymes The TB genome codes for enzymes proteins that inactivate drug molecules. These enzymes usually phosphorylate, acetylate, or adenylate drug compounds. Drug efflux systems The TB cell contains molecular systems that actively pump drug molecules out of the cell. Mutations Spontaneous mutations in the TB genome can alter proteins which are the target of drugs, making the bacteria drug resistant. One example is a mutation in the rpo. B gene, which encodes the beta subunit of the bacterias RNA polymerase. In non resistant TB, rifampin binds the beta subunit of RNA polymerase and disrupt transcription elongation. Mutation in the rpo. B gene changes the sequence of amino acids and eventual conformation of the beta subunit. In this case rifampin can no longer bind or prevent transcription, and the bacteria is resistant. Other mutations make the bacterium resistant to other drugs. For example, there are many mutations that confer resistance to isoniazid INH, including in the genes kat. G, inh. A, ahp. C and others. Amino acid replacements in the NADH binding site of Inh. Stomp Torrent. A apparently result in INH resistance by preventing the inhibition of mycolic acid biosynthesis, which the bacterium uses in its cell wall. Mutations in the kat. G gene make the enzyme catalase peroxidase unable to convert INH to its biologically active form. Hence, INH is ineffective and the bacteria is resistant. In some TB bacteria, the acquisition of these mutations can be explained other mutations in the DNA recombination, recognition and repair machinery. Mutations in these genes allow the bacteria to have a higher overall mutation rate and to accumulate mutations that cause drug resistance more quickly. Extensively drug resistant TBeditMDR TB can become resistant to the major second line TB drug groups fluoroquinolones moxifloxacin, ofloxacin and injectable aminoglycoside or polypeptide drugs amikacin, capreomycin, kanamycin. When MDR TB is resistant to at least one drug from each group, it is classified as extensively drug resistant tuberculosis XDR TB. In a study of MDR TB patients from 2. About 9 of MDR TB cases are resistant to a drug from both classes and classified as XDR TB. In the past 1. 0 years TB strains have emerged in Italy, Iran, India, and South Africa which are resistant to all available first and second line TB drugs, classified as totally drug resistant tuberculosis, though there is some controversy over this term. Increasing levels of resistance in TB strains threaten to complicate the current global public health approaches to TB control. New drugs are being developed to treat extensively resistant forms but major improvements in detection, diagnosis, and treatment will be needed. PreventioneditThere are several ways that drug resistance to TB, and drug resistance in general, can be prevented 2. Rapid diagnosis treatment of TB One of the greatest risk factors for drug resistant TB is problems in treatment and diagnosis, especially in developing countries. If TB is identified and treated soon, drug resistance can be avoided. Completion of treatment Previous treatment of TB is an indicator of MDR TB. If the patient does not complete hisher antibiotic treatment, or if the physician does not prescribe the proper antibiotic regimen, resistance can develop. Also, drugs that are of poor quality or less in quantity, especially in developing countries, contribute to MDR TB. Patients with HIVAIDS should be identified and diagnosed as soon as possible. They lack the immunity to fight the TB infection and are at great risk of developing drug resistance. Identify contacts who could have contracted TB i.