Prevalence of human immunodeficiency virus among pulmonary tuberculosis patients: A cross-sectional study
MICROBIOLOGY AND IMMUNOLOGY
Authors: Moglad, Ehssan H. O.; Ahmed, Dalia A. O.; Al-Kareem, Samah M. M. Awad; Elgoraish, Amanda G.; Ali, Hatim T. O.; Altayb, Hisham N.
Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is an endemic disease in Sudan, where it has rapidly become the major complication of human immunodeficiency virus (HIV) infection. Thus, this study aimed to determine the prevalence of HIV among TB patients and evaluate the co-infection rate. The association of HIV prevalence with gender, age, and duration of treatment as risk factors was also determined. A descriptive cross-sectional study was performed in Omdurman Abu Anga Hospital, Khartoum, Sudan, from October 2018 to March 2019. A total of 281 blood samples were obtained randomly from pulmonary TB patients. The plasma was examined for the presence of HIV antibodies using sandwich ELISA. A structured questionnaire was used during data collection. A noticeable marker for HIV immunoglobulin M/immunoglobulin G was found in 12 patients (4.3%), of which five patients (41.7%) were diagnosed as new TB cases. Moreover, the relationship between age, sex, and duration of TB treatment and the prevalence of HIV was not significantly different (P > 0.05). In conclusion, the prevalence of HIV antibodies among TB pulmonary patients is high. Therefore, all TB patients should be examined for HIV risk factors and advised to undergo HIV testing. Further studies are essential to provide more insights into the epidemiology of the co-infection to better report the double burden of HIV and TB among TB patients in Sudan.
Structural and Functional Characterization of Phosphatidylinositol-Phosphate Biosynthesis in Mycobacteria
JOURNAL OF MOLECULAR BIOLOGY
Authors: Dufrisne, Meagan Belcher; Jorge, Carla D.; Timoteo, Cristina G.; Petrou, Vasileios, I; Ashraf, Khuram U.; Banerjee, Surajit; Clarke, Oliver B.; Santos, Helena; Mancia, Filippo
In mycobacteria, phosphatidylinositol (PI) acts as a common lipid anchor for key components of the cell wall, including the glycolipids phosphatidylinositol mannoside, lipomannan, and lipoarabinomannan. Glycolipids in Mycobacterium tuberculosis, the causative agent of tuberculosis, are important virulence factors that modulate the host immune response. The identity-defining step in PI biosynthesis in prokaryotes, unique to mycobacteria and few other bacterial species, is the reaction between cytidine diphosphate-diacylglycerol and inositol-phosphate to yield phosphatidylinositol-phosphate, the immediate precursor to Pl. This reaction is catalyzed by the cytidine diphosphate-alcohol phosphotransferase phosphatidylinositol-phosphate synthase (PIPS), an essential enzyme for mycobacterial viability. Here we present structures of PIPS from Mycobacterium kansasii with and without evidence of donor and acceptor substrate binding obtained using a crystal engineering approach. PIPS from Mycobacterium kansasii is 86% identical to the ortholog from M. tuberculosis and catalytically active. Functional experiments guided by our structural results allowed us to further characterize the molecular determinants of substrate specificity and catalysis in a new mycobacterial species. This work provides a framework to strengthen our understanding of phosphatidylinositol-phosphate biosynthesis in the context of mycobacterial pathogens. (C) 2020 Elsevier Ltd. All rights reserved.