Elevation of CD56brightCD16- lymphocytes in MDR pulmonary tuberculosis

Background: Protective immune responses induced in the majority of people infected with Mycobacterium tuberculosis enable them to control TB infection. Objective: The aim of this study was to investigate CD56 and CD16 positive peripheral blood mononuclear cells (PBMCs) and leukocyte subsets from multi-drug resistant pulmonary tuberculosis (MDR-TB), and compare them with nonresistant (NR) TB patients and healthy controls. Methods: 13 MDR-tuberculosis patients, 20 NR-TB individuals and 40 healthy subjects were included. Peripheral blood mononuclear cells were double stained with fluorochrome conjugated antibodies against CD56 and CD16 cell surface markers. The phenotype of positive cells was then analyzed by flow cytometry and the percent- ages of CD56+ CD16+, CD56- CD16+, CD56dimCD16+/-, and CD56brightCD16+/- subsets were calculated. Results: There was a significant decline in the percentage of CD56+CD16+ lymphocytes in both MDR and NR-TB patients compared with healthy controls. We also observed lower proportions of CD56dim/brightCD16+ in addition to higher percentages of CD56dim/brightCD16- subsets in all TB patients (p�0.05). In MDR- TB, our findings demonstrated a distinct phenotypic feature with increased levels of CD56brightCD16- in comparison with both NR-TB and healthy subjects. Conclusion: Considering the function of CD56/CD16 expressing cells in TB, we suggest that pheno- typic characteristics of PBMCs in MDR-TB may correlate with their status of drug re- sistance and probably with their high mortality rates

Primary multi-drug resistant tuberculosis presented as lymphadenitis in a patient without HIV infection

Primary multi-drug resistant extrapulmonary tuberculosis is an uncommon form of the disease, but it seems that by increasing the number drug resistant tuberculosis around the world, the number of cases of primary multidrug resistant tuberculosis with extrapulmonary presentation also is going to rise. In this report, we describe a 19- year old, HIV negative man with primary multi-drug resistant TB lymphadenitis, presented with cervical lymphadenopathy and sinus discharge at the site of involved lymph nodes. The Acid Fast Bacilli (AFB) smear of sputum was negative but the AFB smear of discharged fluid as well as the excisional biopsy of the lymph nodes confirmed the M. tuberculosis infection. The patient underwent the treatment with a combination of isoniazide, clofazimine, pyrazinamide, ofloxacin and amikacin with promising results. By increasing the number of drug resistant tuberculosis patients around the world, appropriate diagnosis and treatment of different presentations of the disease need a special attention

Mycobacterium Bovis infection in children in the same family: transmission through inhalation

Two children in the same family were infected with Mycobacterium bovis (“M. bovis”). The molecular typing showed an identical source of infection. Althoughon school of thought was that the route of transmission was by ingestion of contaminated dairy milk, in other it was thought to be by air-borne transmission. The presentation highlighted the possibility of M. bovis infection in the pediatrics populations through aerosols

The Recent-Transmission of Mycobacterium tuberculosis Strains among Iranian and Afghan Relapse Cases: a DNA-fingerprinting using RFLP and spoligotyping

<p>Abstract</p> <p>Background</p> <p>Relapse of tuberculosis (TB) may develop as the result of reactivation of the endogenous primary infection, or as a result of a exogenous reinfection. This survey evaluated the rate of reactivation versus recent transmission among Iranian and Afghan relapse cases.</p> <p>Methods</p> <p>The sputum specimens were digested, examined microscopically for acid-fast bacilli, and inoculated into Löwenstein-Jensen slants by standard procedures. Thereafter, the susceptibility and identification tests were performed on culture positive specimens. Subsequently, the strains that were identified as <it>Mycobacterium tuberculosis </it>(258 isolates) were subjected to IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping. Additional patient's information was collected for further epidemiological analysis. Patients whose isolates had identical genotyping patterns were considered a cluster with recent transmission episode.</p> <p>Results</p> <p>Out of 258 available isolates, 72(28%) had multi-drug resistant (MDR-TB) in ratio and 42 (16.2%) had other resistant. Notably, 38 of MDR-TB cases (52%) were isolated from Afghan patients. By IS6110-RFLP typing method, 65 patients (25%) were clustered in 29 clusters. In cluster cases, the intra-community transmissions between Iranian and Afghan patients were 41%. All MDR-TB patients in clusters had either Haarlem I or Beijing characteristic. The risk factors like sex, family history, close contact, living condition, PPD test result and site of TB infection were not associated with clustering. Although, the MDR-TB strains were more frequent in non-cluster cases (31%) than cluster one(18%) (P < 0.05). Majority of <it>M. tuberculosis </it>strains isolated from non-cluster cases were belong to EAI3 (51; 30%) and CASI(32;18.6%) superfamilies.</p> <p>Conclusion</p> <p>During the studied period, reactivation of a previous infection remain the more probable cause of recurrence. Although, the evidence of intra- community transmission between Iranian and Afghan TB cases, highlighted the impact of afghan immigrants in national tuberculosis control program (NTP) of Iran.</p

Pulmonary Mycobacterium Simiae infection and HTLV1 infection: an incidental co-infection or a predisposing factor?

There is little information on atypical mycobacterium and human T lymphothropic virus Type I (HTLV-I) co-infection. We present the first case of pulmonary M. simiae infection in co-infection with HTLV-1, confirmed by ELISA antibody test and Western Blot. We discuss the clinical characteristics and laboratory tests of the patient and presumptive immunological relation. We propose that in patients with the HTLV infection and pulmonary symptoms and signs compatible with tuberculosis, evaluation for atypical mycobacteriosis may be recommendable

DNA repair systems and the pathogenesis of Mycobacterium tuberculosis: varying activities at different stages of infection

Mycobacteria, including most of all MTB (Mycobacterium tuberculosis), cause pathogenic infections in humans and, during the infectious process, are exposed to a range of environmental insults, including the host's immune response. From the moment MTB is exhaled by infected individuals, through an active and latent phase in the body of the new host, until the time they reach the reactivation stage, MTB is exposed to many types of DNA-damaging agents. Like all cellular organisms, MTB has efficient DNA repair systems, and these are believed to play essential roles in mycobacterial pathogenesis. As different stages of infection have great variation in the conditions in which mycobacteria reside, it is possible that different repair systems are essential for progression to specific phases of infection. MTB possesses homologues of DNA repair systems that are found widely in other species of bacteria, such as nucleotide excision repair, base excision repair and repair by homologous recombination. MTB also possesses a system for non-homologous end-joining of DNA breaks, which appears to be widespread in prokaryotes, although its presence is sporadic within different species within a genus. However, MTB does not possess homologues of the typical mismatch repair system that is found in most bacteria. Recent studies have demonstrated that DNA repair genes are expressed differentially at each stage of infection. In the present review, we focus on different DNA repair systems from mycobacteria and identify questions that remain in our understanding of how these systems have an impact upon the infection processes of these important pathogens