Blood cultures for the diagnosis of multidrug-resistant and extensively drug-resistant tuberculosis among HIV-infected patients from rural South Africa: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The yield of mycobacterial blood cultures for multidrug-resistant (MDR) and extensively drug-resistant tuberculosis (XDR-TB) among drug-resistant TB suspects has not been described.</p> <p>Methods</p> <p>We performed a retrospective, cross-sectional analysis to determine the yield of mycobacterial blood cultures for MDR-TB and XDR-TB among patients suspected of drug-resistant TB from rural South Africa. Secondary outcomes included risk factors of <it>Mycobacterium tuberculosis </it>bacteremia and the additive yield of mycobacterial blood cultures compared to sputum culture.</p> <p>Results</p> <p>From 9/1/2006 to 12/31/2008, 130 patients suspected of drug-resistant TB were evaluated with mycobacterial blood culture. Each patient had a single mycobacterial blood culture with 41 (32%) positive for <it>M. tuberculosis</it>, of which 20 (49%) were XDR-TB and 8 (20%) were MDR-TB. One hundred fourteen (88%) patients were known to be HIV-infected. Patients on antiretroviral therapy were significantly less likely to have a positive blood culture for <it>M. tuberculosis </it>(p = 0.002). The diagnosis of MDR or XDR-TB was made by blood culture alone in 12 patients.</p> <p>Conclusions</p> <p>Mycobacterial blood cultures provided an additive yield for diagnosis of drug-resistant TB in patients with HIV from rural South Africa. The use of mycobacterial blood cultures should be considered in all patients suspected of drug-resistant TB in similar settings.</p

Extensively Drug-Resistant Mycobacterium tuberculosis from Aspirates, Rural South Africa

The yield from aspirating lymph nodes and pleural fluid for diagnosing extensively drug-resistant (XDR) tuberculosis is unknown. Mycobacterium tuberculosis was cultured from lymph node or pleural fluid aspirates of 21 patients; 7 (33%) cultures grew XDR M. tuberculosis. Additive diagnostic yield for XDR M. tuberculosis was found in parallel culture of sputum and fluid aspirate

Expression of mucosal chemokines TECK/CCL25 and MEC/CCL28 during fetal development of the ovine mucosal immune system

CCL25/TECK and CCL28/MEC are CC chemokines primarily expressed in thymic dendritic cells and mucosal epithelial cells. The cognate receptors of CCL25 and CCL28, CCR9 and CCR10, respectively, are mainly expressed on T and B lymphocytes. In human, mouse and pig, CCL25 and CCL28 play a key role in the segregation and the compartmentalization of the mucosal immune system through recruitment of immune cells to specific locations. However, little is known about their role in the ontogeny of the mucosal immune system during fetal development. In the present paper, we report the cloning and the sequencing of ovine CCL25, CCL28, CCR9 and CCR10 and the subsequent assessment of their mRNA expression by q-polymerase chain reaction in several tissues, including thymus, gut-associated lymphoid tissue and mammary gland, from young and adult sheep and in the fetal lamb during the development of the immune system. CCL25 mRNA was highly expressed in thymus and gut while CCL28 mRNA was more expressed in large intestine, trachea, tonsils and mammary gland, especially at the end of gestation. These results are consistent with observations in other species suggesting similar roles for these chemokines in sheep. In fetuses, mRNA of CCL25, CCL28 and their receptors are expressed early in the thymus and mucosal tissues, including the small intestine and the nasal mucosa. Furthermore, their expression increased towards the end of gestation. Consequently, we hypothesize that CCL25 and CCL28 play an important role in the lymphocyte colonization of fetal tissues, enabling the development of a functional immune system