The aim of the study was to estimate the occurrence of Mycobacterium infections in psittacine birds kept in zoological gardens as well as in private aviaries in Poland based on the presence of acid-fast bacilli in the faeces of parrots. All samples taken were decontaminated with 5% oxalic acid. The material obtained was cultured onto L-J media and in BACTEC MGIT 960 system. Faecal smears on mic...

The influence of iron levels on the transcription of the hupB gene in Mycobacterium tuberculosis is the focus of this study. Studies in our laboratory showed HupB to be co-expressed with the two siderophores in low-iron organisms. Mycobactin biosynthesis is repressed by the IdeR-Fe(2+) complex that binds the IdeR box in the mbtB promoter. Recently, we demonstrated the positive regulatory effect...

A single pure component was isolated from mycobactin P by countercurrent distribution; its side chain is n-cis-octadec-2-enoyl; its purity and molecular structure were confirmed by mass spectrometry of its aluminium complex. The separation of ferric and of aluminium complexes of mycobactins by thin-layer chromatography is described. Mycobacterium terrae, M. marinum and M. smegmatis produce myco...

Iron limitation and the expression of mycobactin and carboxymycobactin by Mycobacterium tuberculosis are known. Here, we report how iron regulated the coordinate expression of these two siderophores and a 28-kDa cell wall-associated iron-regulated protein (Irep-28). Irep-28 is identified as the DNA-binding HU homologue HupB protein (hupB [Rv2986c]). Antibodies to this protein were detected in s...

Mycobacterium tuberculosis requires iron for normal growth but faces a limitation of the metal ion due to its low solubility at biological pH and the withholding of iron by the mammalian host. The pathogen expresses the Fe(3+)-specific siderophores mycobactin and carboxymycobactin to chelate the metal ion from insoluble iron and the host proteins transferrin, lactoferrin, and ferritin. Sideroph...

Mycobacteria such as M. tuberculosis represent a significant health concern throughout much of the developing world. In mycobacteria and other pathogenic bacteria, an important virulence factor is the ability of the bacterium to obtain iron from its host. One means of obtaining iron is through the use of siderophores. Brasilibactin A is a membrane bound siderophore produced by Nocardia brasilie...

Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's disease in cattle and sheep, has unique iron requirements in that it is mycobactin-dependent for cultivation in vitro. The iron-dependent regulator (IdeR) is a well-characterized global regulator responsible for maintaining iron homeostasis in Mycobacterium tuberculosis (MTB). We identified an orthologous segm...

Siderophores are small iron-binding molecules secreted by bacteria to scavenge iron. Mycobacterium tuberculosis (Mtb), the etiologic agent of tuberculosis, produces the siderophores mycobactin and carboxymycobactin. Complexes of the mycobacterial membrane proteins MmpS4 and MmpS5 with the transporters MmpL4 and MmpL5 are required for siderophore export and virulence in Mtb. Here we show that, s...