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Streptococcus pneumoniae and Mycobacterium tuberculosis

About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.

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Streptococcus pneumoniae and Mycobacterium tuberculosis

Postby Inuyasha » Thu Dec 15, 2005 1:23 am

Streptococcus pneumoniae and Mycobacterium tuberculosis are pulmonary infections. Explain why it is possible to treat and cure pneumoncoccal infection with one antibiotic while it takes two or more for M. tuberculosis.
Does anyone have any good websites? or info.
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Postby canalon » Thu Dec 15, 2005 2:49 am

Not so long ago one antibiotic was enough to get rid of Mycobacterium tuberculosis but poor compliance and bad usage of antibiotic treatments have selected for such high levels of resistance that protocols now have to usually on tritherapy. The good side of it is that it makes a less more unlikely that any resistance appear. Provided compliance, of course
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Postby Inuyasha » Thu Dec 15, 2005 6:00 am

and what about strept, i heard there were a lot of strains that have become resistant to anitbiotics such as pencillin. So why is taking one anitbiotic enough?
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Postby canalon » Thu Dec 15, 2005 2:33 pm

Inuyasha wrote:and what about strept, i heard there were a lot of strains that have become resistant to anitbiotics such as pencillin. So why is taking one anitbiotic enough?


Well, I don't have data about resistance of this species, but I guess that at least in some case you have either to treat with multiple antibiotics or that by testing you can find one that is still efficient.
Another point is it seems to easier to treat strep infections. So compliance is probably better, hence selection for resistants is lower. Nevertheless it seems that there is a lot of resistance around too, but not yet (significantly) to some molecules like (fluoro)quinolones.
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Postby Inuyasha » Fri Dec 16, 2005 10:10 pm

Here's the rough for my other paper. Oh yeah I need to know if strept produces faster than TB. I really need to know that.


1 or 2 Treatments Needed
Pneumococcal infection is normally treated with one antibiotic while M. tuberculosis is normally treated with two or more.
Penicillin is faintly susceptible against Streptococcus pneumoniae. Erythrocmycin can be used if the patient does not react favorably to penicillin. In the beginning, S. pneumoniae was found to be incredibly susceptible to penicillin. A dose of penicillin would usually eliminate most Streptococci. In 1977, a strain of penicillin-resistant S. pneumoniae surfaced in South Africa. Penicillin resistance and multi-drug resistance S. pneumoniae have spread worldwide. A lot of the penicillin resistant strains are also resistant to chloramphenicol, erythromycin, tetracycline and trimethoprim-sulfamethoxazole. Treatment with a single antibiotic is standard for S. pneumoniae. Even with the resistant S. pneumoniae around, there are molecules like (fluoro)quinolones that S. pneumoniae has not developed strong resistance against. Infections can be treated with drugs that S. pneumoniae does not have resistance for yet. Because S. pneumoniae drugs can be taken orally compliance for taking the drugs is high. Selection for resistant strands is moderately low for several of the new drugs used to treat S. pneumoniae.
For M. tuberculosis several drugs need to be taken at the same time. Average single drug resistant M. tuberculosis occurs with a frequency of 10-6 (although individual resistances differ). M. tuberculosis can produce resistant strands for several of the drugs used to treat the disease. Resistance to streptomycin is 10-5, resistance to INH is 10-6, and resistance to rifampin is 10-8. By taking two drugs at the same time the odds of M. tuberculosis having resistance to one drug are multiplied with the odds of M. tuberculosis having resistance to the other drug. The chance that an organism is naturally resistant to both INH and rifampin is 10-14 (10-6multipied by 10-8). There are not normally 10-14 in patients, so M. tuberculosis resistant to both INH and rifampin is basically slim. When a single drug is given to a patient, M. tuberculosis susceptible to that drug is eradicated, but resistant strands continue to multiply. The M. tuberculosis left already has resistance to one drug and may multiply and mutate for resistance to other drugs. It is essentially a numbers game. Present treatments for M. tuberculosis include a 6 month course of INH and rifampin, supplemented with pyrazinamide during the first 2 months. Poor compliance for treatments for M. tuberculosis have selected for multi-resistant strands.
S. pneumoniae is normally treated with one antibiotic because the susceptibly to many single antibiotics is high. But as the usage of penicillin showed, resistance to antibiotics can develop when administration compliance is poor. Currently, compliance to the remaining antibiotics used to treat S. pneumoniae is high. M. tuberculosis needs to be treated with several drugs. The chance of M. tuberculosis being resistant to two or three drugs is low. In the majority of cases M. tuberculosis can not develop resistance to two or three drugs because there is not enough M. tuberculosis for that random event to occur. It is a numbers game. M. tuberculosis compliance in the past has been low. Now persons who have M. tuberculosis must be administrated by a professional. This reduces the odds of multi-drug resistance because the professional can make certain the patient is taking all his/her drugs.

Work Cited

"Tuberculosis." Tuberculosis. Wikipedia. 15 Dec. 2005 <http://en.wikipedia.org/wiki/Tuberculosis>.

" Streptococcus." Streptococcus. Wikipedia. 15 Dec. 2005 <http://en.wikipedia.org/wiki/Streptococcus>.

"Streptococcus pneumoniae ." Streptococcus pneumoniae - An Emerging Threat?. Microbiology and Bacteriology. 15 Dec. 2005 <http://www.bact.wisc.edu/Microtextbook/index.php?name=Sections&req=viewarticle&artid=166&page=1>.
Last edited by Inuyasha on Thu Dec 22, 2005 12:19 am, edited 1 time in total.
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Postby canalon » Sat Dec 17, 2005 6:44 pm

Yep M. Tuberculosis replicate extremely slowly (it can take weeks to see a colony on extremely rich media, so S. pneumoniae replicates much faster.
I do not have time for a full review of your paper but:
-Ampicillin is not susceptible to S. pneumoniae, rather the opposite ;)
-Resistance to any ATB is not 10-something, its the frequency of resistant mutants in the population, or The odds to find a resistant in the population...
-Not strands, strains...
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