Wolbachia-induced transcription factor GATA4 suppresses ovary-specific genes blastoderm-specific protein 25D and imaginal disc growth factor

The endosymbiotic bacterium Wolbachia infects a wide array of insect hosts and has been implicated in a range of biological modifications as a consequence of its infection. Previously, it was shown that the transcription factor GATA4 was significantly induced in Wolbachia wMelPop-CLA strain infected Aedes aegypti whole mosquitoes and cells. Here, we provide evidence that this induction also occurs in mosquito ovaries where the ovary-specific genes blastoderm-specific protein 25D (Bsg25D) and imaginal disc growth factor (Disc) are suppressed by Wolbachia. We further demonstrate that transcriptional depletion of GATA4 results in upregulation of both genes and conversely its overexpression leads to downregulation of the genes, suggesting that Wolbachia-induced GATA4 plays a suppressive regulatory role with regards to Bsg25D and Disc expression in mosquito ovaries. When the Disc gene was silenced in mosquitoes, we did not observe any difference in the number of mature ovarian follicles developed between treatment groups. However, we did find a significant delay in the hatching of eggs that had been laid by Disc knockdown mosquitoes

Second-line anti-tuberculosis drug resistance testing in Ghana identifies the first extensively drug-resistant tuberculosis case

Stephen Osei-Wusu,1,2 Michael Amo Omari,3 Adwoa Asante-Poku,1 Isaac Darko Otchere,1 Prince Asare,1 Audrey Forson,3 Jacob Otu,4 Martin Antonio,4 Dorothy Yeboah-Manu1 1Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana; 2West Africa Centre for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana; 3Department of Chest Diseases, Korle-Bu Teaching Hospital, Accra, Ghana; 4Medical Research Council Unit, Fajara, The Gambia Background: Drug resistance surveillance is crucial for tuberculosis (TB) control. Therefore, our goal was to determine the prevalence of second-line anti-TB drug resistance among diverse primary drug-resistant Mycobacterium tuberculosis complex (MTBC) isolates in Ghana. Materials and methods: One hundred and seventeen MTBC isolates with varying first-line drug resistance were analyzed. Additional resistance to second-line anti-TB drugs (streptomycin [STR], amikacin [AMK] and moxifloxacin [MOX]) was profiled using the Etest and GenoType MTBDRsl version 2.0. Genes associated with resistance to AMK and MOX (gyrA, gyrB, eis, rrs, tap, whiB7 and tlyA) were then analyzed for mutation. Results: Thirty-seven (31.9%) isolates had minimum inhibitory concentration (MIC) values ≥2 µg/mL against STR while 12 (10.3%) isolates had MIC values ≥1 µg/mL for AMK. Only one multidrug-resistant (MDR) isolate (Isolate ID: TB/Nm 919) had an MIC value of ≥0.125 µg/mL for MOX (MIC = 3 µg/mL). This isolate also had the highest MIC value for AMK (MIC = 16 µg/mL) and was confirmed as resistant to AMK and MOX by the line probe assay GenoType MTBDRsl version 2.0. Mutations associated with the resistance were: gyrA (G88C) and rrs (A514C and A1401G). Conclusion: Our findings suggest the need to include routine second-line anti-TB drug susceptibility testing of MDR/rifampicin-resistant isolates in our diagnostic algorithm. Keywords: tuberculosis, drug resistance, diagnosis, Ghana, XD