Mycobacterium tuberculosis Small RNA MTS1338 Confers Pathogenic Properties to Non-Pathogenic Mycobacterium smegmatis

Small non-coding RNAs play a key role in bacterial adaptation to various stresses. Mycobacterium tuberculosis small RNA MTS1338 is upregulated during mycobacteria infection of macrophages, suggesting its involvement in the interaction of the pathogen with the host. In this study, we explored the functional effects of MTS1338 by expressing it in non-pathogenic Mycobacterium smegmatis that lacks the MTS1338 gene. The results indicated that MTS1338 slowed the growth of the recombinant mycobacteria in culture and increased their survival in RAW 264.7 macrophages, where the MTS1338-expressing strain significantly (p < 0.05) reduced the number of mature phagolysosomes and changed the production of cytokines IL-1β, IL-6, IL-10, IL-12, TGF-β, and TNF-α compared to those of the control strain. Proteomic and secretomic profiling of recombinant and control strains revealed differential expression of proteins involved in the synthesis of main cell wall components and in the regulation of iron metabolism (ESX-3 secretion system) and response to hypoxia (furA, whiB4, phoP). These effects of MTS1338 expression are characteristic for M. tuberculosis during infection, suggesting that in pathogenic mycobacteria MTS1338 plays the role of a virulence factor supporting the residence of M. tuberculosis in the host.

Polymer-coated TiO2 nanoparticles bioaccumulate, immunoactivate and suppress pathogenic Mycobacterium chelonae clearance when intravenously injected into goldfish (Carassius auratus L.)

We examined goldfish immunotoxicological responses to intravenously injected PAA-TiO2 NPs by determining organ accumulation, depuration, tissue damage, and immune responsiveness in the kidneys, spleen, and isolated primary kidney neutrophils.

Genomic Insights into the Fish-Pathogenic Mycobacterium pseudoshottsii Strain AR Recovered from Meagre (Argyrosomus regius)

ABSTRACT Mycobacteriosis can cause morbidity and mortality and is characterized as a disease with zoonotic potential that is found worldwide in both fresh and marine fish. Here, we report the draft genome sequence of Mycobacterium pseudoshottsii strain AR, an isolate recovered from infected meagre (Argyrosomus regius) raised on farms in Greece.