| 2016 | Mycobacteriophage SWU1 gp39 can potentiate multiple antibiotics against Mycobacterium via altering the cell wall permeability. | Sci Rep | M. tuberculosis is intrinsically tolerant to many antibiotics largely due to the imperviousness of its unusual mycolic acid-containing cell wall to most antimicrobials. The emergence and increasingly widespread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) revitalized keen interest in phage-inspired therapy. SWU1gp39 is a novel gene from mycobacteriophage SWU1 with unknown function. SWU1gp39 expressed in M. smegmatis conferred the host cell increased susceptibility to multiple antibiotics, including isoniazid, erythromycin, norfloxacin, ampicillin, ciprofloxacin, ofloxacin, rifampicin and vancomycin, and multiple environment stresses such as H2O2, heat shock, low pH and SDS. By using EtBr/Nile red uptake assays, WT-pAL-gp39 strain showed higher cell wall permeability than control strain WT-pAL. Moreover, the WT-pAL-gp39 strain produced more reactive oxygen species and reduced NAD(+)/NADH ratio. RNA-Seq transcriptomes of the WT-pAL-gp39 and WT-pAL revealed that the transcription of 867 genes was differentially regulated, including genes associated with lipid metabolism. Taken together, our results implicated that SWU1gp39, a novel gene from mycobacteriophage, disrupted the lipid metabolism of host and increased cell wall permeability, ultimately potentiated the efficacy of multiple antibiotics and stresses against mycobacteria. |
| 2011 | PPE_MPTR genes are differentially expressed by Mycobacterium tuberculosis in vivo. | Tuberculosis (Edinb) | The PPE_MPTR protein sub-family is unique to mycobacteria and comprises proteins found only in MTB complex and in few other pathogenic mycobacteria. Very little is known about the precise function of PPE_MPTR, as well as on the expression pattern and the transcriptional regulation of their structural genes. In the present work, real time RT-PCR techniques were used to determine the expression profile of PPE_MPTR genes of Mycobacterium tuberculosis during infection in vivo and in different culture conditions. The PPE_MPTR genes showed a similar expression profile in axenic cultures, with a significant increase of gene expression following exposure to environmental signals such as SDS, isoniazid and ethambutol. The PPE_MPTR genes were expressed in lung and spleen tissues infected by M. tuberculosis, and levels of expression were similar to those of genes encoding M. tuberculosis virulence factors such as hbhA and mpt64. Levels and pattern of gene expression in host tissues were different for each PPE_MPTR gene under study. The results of this study indicate that PPE_MPTR genes are differentially regulated in the lung and spleen tissues during M. tuberculosis infection, suggesting that each gene responds independently to the different and complex environmental signals encountered in host tissues. |