• Adam Lai Hung Wei added an answer:
    Which drugs (beside isoniazid & metronidazole) can show significant activity against either acute or latent mycobacterium tuberculosis only in vitro?

    Mycobacterium tuberculosis. Which drugs (beside isoniazid & metronidazole) can show significant activity against either acute or latent mycobacterium tuberculosis only in vitro?

    Adam Lai Hung Wei

    Thank you very much for your help!

  • Utpal Sengupta added an answer:
    Is decontamination mandatory for all samples (blood, sputum, endometrial tissue, csf) in the case of DNA extraction for TB diagnosis by RT-PCR?
    We are not getting reproducible results.
    Utpal Sengupta

    Yes, I agree with Nkiru. As sputum and endometrial tissue will contain other mycobacteria these specimens should be decontaminated before mycobacterial culture.

  • Debebe Shaweno added an answer:
    What is the progression risk of Latent TB Infection?

    One of the issue which we do not clearly know about tuberculosis biology is the risk or rate of progression from latent infection to active TB diseases. However, ones  life time risk of progression from latent TB to active TB is reported  to be between 5 to 10% in the absence of other risk factors such as HIV in many  documents. Sadly, these reports  are not citing the original  studies (if they ever have existed).

    So can I find the relevant original references? Opinions on the risk of progression?


    University of Melbourne 

    Debebe Shaweno

    ok thanks. no mention in CDC

  • Wladimir Queiroz added an answer:
    How is malnutrition related with the prevalence of TB?

    Tsedeke Wolde and Eyasu Ejeta, Jimma University

    Wladimir Queiroz

    The association between poor nutrition and inability in developing an appropriate immune response to M tuberculosis seems very clear.

  • Nikola Ilankovic added an answer:
    Does TB (Tuberculosis) spread through housefly like Muska-Domestica?
    TB is transmitted through the air. The droplet nuclei generated when a sputum positive pulmonary TB patients coughs, mixes in the air and are carried to a susceptible person in the vicinity or by air currents to longer distances. Sputum Negative TB patients may also contribute in transmission of infection to a smaller extent. Now my concern is that, "Can housefly provides an additional epidemiological link to spread TB infection in the community?"
    Nikola Ilankovic

    I agree Anthony. And then all dependence from  imunological status of body, too.

    But the bacteriological investigation of tissue must be primary, or in the same time with pathohystology.

  • Eman Sobh added an answer:
    When do Tubercular Cervical Lymphadenopathy need excision?

    We know Tubercular Cervical Lymphadenopathies resolve with anti-TB drugs. When do Tubercular Cervical Lymphadenopathy need excision?

    Eman Sobh

    in the past surgical excision combined with antituberculous drugs was considered effective. after advent of short course chemotherapy surgical ttt rarely required eg for persistent or recurrent, ttt failure or if there is doubt about diagnosis.

    some still recommend surgery combined with medical ttt

    you can see

  • Utpal Sengupta added an answer:
    Does anyone experience that TB strain loses its virulence after passing in culture several times?

    My TB strain (H37Rv) seems losing virulence after passing in liquid culture several times. Looks like that the growth rate in liquid culture (7H9+10%OADC) or on plates (7H11+10% OADC) slows down when stock is 1) stored at -20 degree for long period of time, 2-3 years; 2) in higher passage. We use 7H9+10% glycerol to stock down TB. Does anyone have similar experiences? What are the solutions for these issues? Thanks!

    Utpal Sengupta

    Most of the bacterial isolates lose their virulence in continuous culture. To get back  its virulence it has to be passaged through its host.

  • Rajendran Natham added an answer:
    What is the current trend of drug resistant Tuberculosis in Uganda?

    Hello researchers am trying to find out the current trend of drug resistant TB in Uganda based on your observations and experiences.

    Rajendran Natham

    One of the factors influencing resistant to multi drug therapy in tuberculosis is poor bioavailability of rifampicin.Clinical therapy recommends 1000mg ascorbic acid intake with multidrugs which is not followed in clinical practice as reports suggest. In our preclinical study We observed improved bioavailability of rifampicin in the presence of ascorbic acid and the work was published in Journal of Biomedical and Pharmaceutical. Analysis. In my view co administration of ascorbic acid may help overcome resistance owing to poor bioavailability of rifampicin. Besides ascorbic acid suppresses the cultures of the bacteria in blood.

  • Evangelina Inacio Namburete added an answer:
    If i want to ship TB positive isolates from one country to other, what kind of shipment it should be?

    if i want to ship TB positive isolates from one country to other, what kind of shipment it should be? dry-ice shipment or ambient shipment by FedEx or shipment using ice pack?

    Please help me. I already have the permit. 

    Evangelina Inacio Namburete


    For sure you have to follow IATA Guidelines. Make sure that if you are transporting isolates of  a bacteria or mycobacterium , you will need to pack it according to guidelines for standard precaution - Biological Dangerous Category "A"

    We have used World courier company (

    they assist you with the documents


  • Donald Konts Ngants added an answer:
    What are the influences of potts disease in PNG?

    What causes Spinal TB, the age group that are affected, risk factors and its influence.

    Donald Konts Ngants

    Spinal TB is a secondary infection. Pulmonary TB is a primary infection. Once the pulmonary TB is left untreated, the mycobacterium bacilli travels along the vessels to the spinal column. That is when the initiation of spinal TB occurs.

  • Prosper Adogu added an answer:
    How common is pulmonary hydatid cyst with pulmonary tuberculosis in same patient?

    24 year young boy, admitted in CTVS department for lobectomy of left lung for hydatid cyst, biopsy report was showing e/o hydatid cyst alongwith granulomatous lesion s/o Tuberculosis. I am not getting any review article for the same in the literature except few case reports. 

    Prosper Adogu

    It is an extremely rare phenomenon.

    You might find the article in the link below, helpful;

  • Amera Osama added an answer:
    Which is the best method for decontamination of a sputum sample before culturing it for Mycobacterium tuberculosis?
    I would like to know which is the easiest and cheapest but at the same time sensitive and specific method.
    Amera Osama

    Hello colleagues,

    Thanks much for your valuable answers. I have a question about bleach method: Do you recommend bleach method for sputum liquefaction, prior to DNA extraction of M.Tuberculosis? considering that PCR will be subsequently performed...

    In another word, Does bleach inhibit PCR?

    Thanks much!.

  • Aliabbas A Husain added an answer:
    How can I measure the concentration of TB drugs in organs of mice after chemotherapy? what is the ideal time after therapy to study concentration?

    I am studying efficacy of TB drugs to disseminate in  various organs after drug administration either orally or via IV route. Main aim is to study how much concentration actually reaches the organs after administration for prevention of pulmonary and extra pulmonary TB. Can anyone suggest some good protocols??

    Aliabbas A Husain

    Thanks sir for your valuable information

  • Yogarabindranath Swarna Nantha added an answer:
    What do you conclude when you have prevalence of latent TB infection (LTBI) amongst diabetics that's close to the prevalence of LTBI in the community?

    If the methodology of the study is sound, can you just conclude by saying that being diabetic does not confer an extra risk of being predisposed to latent TB infection (in contrast to having tuberculosis)? Or does this mean that the levels of latent TB in the community is overwhelmingly large that it is almost similar to levels in diabetics?

    Yogarabindranath Swarna Nantha

    Hi Shawn,

     Thanks for your imput. Yes, each patients who tested positive for Mantoux were subjected to chest x-rays.


  • Umamaheshwari S added an answer:
    Can ESR predict TB?

    On infections ESR gets elevated, but correlating with clinical conditions in TB, can ESR serve to predict TB especially in HIV positive and sputum smears are negative/ sputum nonproductive?

    Umamaheshwari S

    Elevated ESR though not a specific test for TB, few TB studies show elevated ESR. obviously correlating with clinical symptoms and elevated ESR can serve as one of the tool to suspec and diagnose especially in smear negative TB cases

  • Umamaheshwari S added an answer:
    Wont Mycobacteria isolated from stool specimen confer TB infection?

    Does isolate from a stool sample prove a person is infected with TB?

    Umamaheshwari S

    I do agree with Mr Werner. Species diagnosis is must to decide treatment

  • Timothy Mark Doherty added an answer:
    Where can I find a paper which shows that zoonotic tuberculosis (M bovis) is not transmissible among immunocompetent humans?

    Recently I read a paper which authors state that zoonotic tuberculosis (M. bovis) is not transmitted among immunocompetent humans.
    Now, when I search, I can't locate it. Can anyone help me?

    Timothy Mark Doherty

    Edit: I should also note that if one really wanted to use the very old literature in this case, then you can easily find reports of human infection with M. bovis attributed to consumption of milk. The article "Reports on bovine tuberculosis and public health. Salmon, D. E. USDA, 1904." lists well over a dozen cases of infection, including some oddball ones such as use of cream (from milk from a cow with tuberculous mastitis) to treat eczema, leading to percutaneous tuberculosis infection, as well as more conventional infections derived from drinking milk from a cow with tuberculous mastitis - including one where 12 girls at a boarding school contracted abdominal tuberculosis (5 of whom died). On investigation of that case, it was found that the cow supplying milk for the girls had tuberculous mastitis. The girls had no other known risk factors and were not in contact with the animal directly, leaving the milk as the only known source of infection.  You can find this report in fascimile online, and there are literally hundreds of similar reports from the first quarter of the 20th century.

    The trouble with using these ancient reports indicating infection is exactly the same as with the ancient reports you referred to above: the science was still evolving and back in the early 20th century they were still investigating questions about host range, transmission and susceptibility that were conclusively settled decades ago. The scientists of the time were smart enough to know how limited their knowledge was. Salmon wrote of the case reports of infection via milk:

    "These are examples of clinical evidence which might be greatly extended, but all are, of course, open to the objection that we do not know absolutely that the disease was caused by the bovine bacillus. However, the occurrence of abdominal tuberculosis soon after the use of milk from tuberculous cows is a coincidence which justifies us in accepting the cases as strong circumstantial evidence, not of themselves demonstrating the communicability of bovine tuberculosis, but, taken with other evidence, making a case which it is difficult to contest."

     In the 21st century, however, we have no such problems and the recent outbreaks in the US already cited not only were proven by typing to be M. bovis, but were linked to the same strains in contaminated unpasteurised dairy products and the strains themselves proven by spoligotyping to overwhelmingly be those circulating in cattle not in the local region (where M bovis infection is rare), but in Mexico (see, for example, Rodwell et al. Tracing the origins of Mycobacterium bovis tuberculosis in humans in the USA to cattle in Mexico using spoligotyping. IJID.  2010, 14: e129–e135. In this case, transmission by direct contact with cattle can be clearly ruled out and a direct line of infection via contaminated dairy produce remains the most likely route of infection (indeed, the only plausible route, in many cases).

    Given the clear evidence available from recent outbreak investigations, why would one resort to musty, century-old studies with weaknesses acknowledged even at the time?

  • Nkiru Nenye Nwokoye added an answer:
    Any advice on tuberculosis screening in HIV-infected patients?

    From a public health standpoint , what  current or future alternatives would you recommend for better tuberculosis screening in HIV-infected patients?

    Nkiru Nenye Nwokoye

    Tuberculosis (TB) is difficult to diagnose in HIV-positive patients because they form poor granulomas resulting in lower concentrations of Mycobacterium tuberculosis (MTB) in lesions.Culture which has higher sensitivity is time consuming and not readily available. In line with the recent WHO recommendation on the use of GeneXpert, Nigeria reviewed its diagnostic algorithm to reflect the use of GeneXpert as first screening test for HIV-infected persons showing symptoms of TB. 

    i must say that with the new algorithm, increased number of HIV-infected persons are being screened for TB and appreciable number are coming out positive for not only susceptible TB but also the drug resistant strains. 

  • María Teresa Herrera added an answer:
    Why I can not find sufficient and well macrophage after PBMCS culture?

    I have a research about phagocytosis activity of macrophage from cell culture of PBMCS from children contact with adult tuberculosis, but I cannot found good macrophage from my culture. I don't know waht happen. Any suggest from other researcher that have more experiend with this procedure?

    María Teresa Herrera

    Hi Finny

    You have to isolate PBMC fron whole blood and then purify monocytes from adherente but I recommend  by positive or negative selection using Miltenyi kit. I have very good experience with Miltenyi kit using an anti-CD14 conjugarte to magnetice beads. The MN population has more than 94% of purity. Just you have to followe the manual instrucción.

    Then you have to resuspend the MN in RPMI+L-glutamine-10% human pool serum not heat inactivated. Count and add in a chamber slide and incubaste 1hr, 37 grade 5% CO2. It let the MN adherent at the plastic. Here you have two alternativas for your experiment: 1) Phagocytosis by MN or 2) Let the MN differentiation tomacrophages by 5-7 days and then study the phagocitosis.

    When we compared the MN rpurification between adherence to plastic and by Miltenyi column, the MN obtained after column there are less lynphocytes contamination.


  • Gehendra Mahara added an answer:
    Can anyone explain to me how to do a study about PM 2.5 and tuberculosis infection?

    Can anyone explain me that how to do a study about PM 2.5 and tuberculosis infection?

    Gehendra Mahara

    Thank you Saileela Kondapaneni madam.

  • Tefera B Agizew added an answer:
    What is a suitable way we can eliminate tuberculosis?

    Do you have suggestions/ideas which can change the statistics of TB in the world?

    Tefera B Agizew

    In my opinion resource and political commitment seem to be the two major key points from the European experience and even from the USA. In the USA we have seen TB resurgence after control and again when resource boosted the TB situation went down hill again. These are clear indications to the road to elimination o TB. All other things, education, awareness, living conditions, application of available best drugs and diagnostics are also key factors. However, controlling or improving these factors depends where you are - low, middle or high income countries. With all these the journey is long but possible.  

  • Jamunanantha Sivanathan added an answer:
    Mycobacteria DNA extraction directly from blood?
    Currently there are some kits allow the extraction of Mycobacteria DNA directly from sputum samples and tissue biopies. Does anyone know any similar fast and simple method for extraction from blood samples?
    Jamunanantha Sivanathan

    Mycobacteria  is an intracellular pathogen and not in the blood circulation.So it is not the correct question.

  • Nagendra Babu Mennuru added an answer:
    Does anyone know Research centers in India that carry out assays for tuberculosis for screening of new compounds?

    Does anyone know any commercial or non-commercial research facilities within India (preferably in Chennai, Hyderabad, Bangalore and rest of India) to perform screening assays for Tuberculosis on new compounds? Added to this I require the results within 15-20 days?

    Nagendra Babu Mennuru

    Dr. Sonali Dalwadi:

    Thank you for the information, I will check these sources....

    Dr. Mayur:

    Thanks for the details, yes, I had contacted through mail regarding the possibility, reply need to be expected....

    Thanks & Regards,

    Nagendra Babu M.

  • Leena Menghaney added an answer:
    Does anyone have any experience in giving Delamanid and Bedaquiline together for the treatment of XDR Tuberculosis?

    I have very limited therapeutic options treating a patient with extensively Drug resistant TB. However there is no evidence in the literature of the association of these two drugs in a regimen. They are now commercially available however there is little consensus to adding them together given the paucity of safety data. Has anyone managed to give the two drugs together, where there any adverse events and/or increases in QTc?

    Leena Menghaney

    you should contact Dr. Homa Mansoor at the MSF Mumbai DR TB Clinic in Mumbai on this very interesting question. Her email is

  • Brian Weinrick added an answer:
    Does M. smegmatis have a homologous enzyme of HsaAB?

    In M. tuberculosis, cholesterol catabolism goes through a complex process. The ring opening process involves production of 3-hydroxy-9,10-seconandrost-1,3,5 (10)-triene-9,17-dione (3-HSA). A flavin-dependent monooxygenase hydroxylates 3-HSA to 3,4-DHSA. I wanted to find out whether M. smegmatis contains a homologue that carries out the hydroxylation reaction. If yes, what is the name of the enzyme and the gene encoding it?

    Brian Weinrick

    Tuberculist shows orthologs MSMEG_6038 and MSMEG_6035 for hsaA and hsaB, respectively:

  • Antonio Cantó added an answer:
    Can anybody tell me how tuberculosis might lead to lung cancer?

    There are so many changes including physiological,histological,biochemical and immunological changes associated with secondary TB. So what is the mechanism that leads to tumour of lung sometimes?

    Antonio Cantó

    Solo conozco el " carcinoma de cicatriz" en tuberculosis ya curadas.

    De acuerdo con los Drs Newhouse y Braenbtll.Saludos

  • Yogarabindranath Swarna Nantha added an answer:
    Can eGFR calculation using S.Creatinine among patients with TB &DM be accurate and is there any other method?

    If S.Creatinine is being used for calculating eGFR , in patients with DM what are the essential parameters  we have to look into.

    Yogarabindranath Swarna Nantha

    Based on my experience (and current research work on LTBI and DM), I feel that MDRD (eGFR) is a suitable measure of kidney function. Having said that, I often take the average/mean of three different reading in a span of 2 years to avoid any inaccuracies in relation to normal biological variation.

    Hope this helps.


  • Lawrence Broxmeyer, MD added an answer:
    Where can I find age-structured incidence data for AIDS defining opportunistic infections starting from before AIDS epidemic in Sub-Saharan Africa?

    I am interesting in finding prevalence/incidence rates of specific opportunistic infections of young age groups (not adult) from before and after the start of the AIDS epidemic (~1980). 

    In particular I am looking for trends in: Tuberculosis, Cryptosporidium, and Non-Typhi Salmonella. 

    Does anyone know if such data exists and where I can find it? I would want to look in an area where HIV/AIDS is widespread, so somewhere in Sub-Saharan Africa would be ideal (or the whole region). 

    Lawrence Broxmeyer, MD

    "Where can I find age-structured incidence data for AIDS defining opportunistic infections starting from before AIDS epidemic in Sub-Saharan Africa?
    I am interesting in finding prevalence/incidence rates of specific opportunistic infections of young age groups (not adult) from before and after the start of the AIDS epidemic (~1980). 

    In particular I am looking for trends in: Tuberculosis, Cryptosporidium, and Non-Typhi Salmonella. "


    Very well. But why go to WHO? Perhaps you should start by seeking statistical data and maps for Tuberculosis and M. avium, which still are the leading causes of infectious death in HIV/AIDS. Before such typical and atypical mycobacteria were proclaimed "AIDS-defining illness" by the likes of WHO, you will notice that they admitted that tubercular disease killed close to 3 million people a year. Then since it has magically  "defined" AIDS -  it is now purported that tubercular disease kills merely a million and a quarter annually. Interesting math.

  • Tony Ete added an answer:
    How can I manage patients with total resistance for anti TB medications?

    There is no convincing guidelines on how I can approach total drug resistance accordingly. So how do we manage patients who are resistant to medication for XDR - TB?

    Tony Ete

    Excluding your list of medications there are many drugs known to be effective in Tuberculosis including PAS,Linezolid,Imipenem plus cilastatin,Clofazimine,Amoxicillin and clavulanate,Clarithromycin.What about them?

  • Mani Sankar added an answer:
    What is the difference in Mycobateria growth in flat vs v (conical) - well shaped 96 - well microtiter plates?
    I have been determining MICs for M. tuberculosis using 96 - well microtiter plates, flat well shape. After five days, I confirm positive growth by adding alamar blue to my controls.

    Recently I ran into a supplier issue and I could not obtain plates with flat wells but had to revert to using V or conical shape wells. After five days of incubation, I add alamar blue. There is difference in the color change. In the flat wells, color change after five days is a distinctive pink, whereas in the v or conical shape wells, it's a purple/violet.

    All conditions remain exactly the same between the two.

    What could cause this issue? Is it a surface area problem? Could it be that cells sink to the bottom in v or conical shaped wells and are not in entire contact with the alamar blue?

    Has anybody else observed such an issue?
    Mani Sankar

    Dear Shane

    I have not performed alamar blue testing using 'V' bottom plates. But the possible reason may be the surface area difference between the flat and V bottom plates. In V bottom plates the cells could settle in the bottom and could produce a high intensity coloring. whereas in the flat bottom plates the cells are dispersed even the coloring would be of less intensity. I recommend you to continue with the 'Flat bottom' plates instead of V bottom which will seriously affect your results and OD values.

    Best regards

About Tuberculosis

Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.

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