Mycobacterium tuberculosis CwsA interacts with CrgA and Wag31, and the CrgA-CwsA complex is involved in peptidoglycan synthesis and cell shape determination.

Bacterial cell division and cell wall synthesis are highly coordinated processes involving multiple proteins. Here, we show that Rv0008c, a novel small membrane protein from Mycobacterium tuberculosis, localizes to the poles and on membranes and shows an overall punctate localization throughout the cell. Furthermore, Rv0008c interacts with two proteins, CrgA and Wag31, implicated in peptidoglycan (PG) synthesis in mycobacteria. Deletion of the Rv0008c homolog in M. smegmatis, MSMEG_0023, caused bulged cell poles, formation of rounded cells, and defects in polar localization of Wag31 and cell wall synthesis, with cell wall synthesis measured by the incorporation of the [(14)C]N-acetylglucosamine cell wall precursor. The M. smegmatis MSMEG_0023 crgA double mutant strain showed severe defects in growth, viability, cell wall synthesis, cell shape, and the localization of the FtsZ, FtsI, and Wag31 proteins. The double mutant strain also exhibited increased autolytic activity in the presence of detergents. Because CrgA and Wag31 proteins interact with FtsI individually, we believe that regulated cell wall synthesis and cell shape maintenance require the concerted actions of the CrgA, Rv0008c, FtsI, and Wag31 proteins. We propose that, together, CrgA and Rv0008c, renamed CwsA for cell wall synthesis and cell shape protein A, play crucial roles in septal and polar PG synthesis and help coordinate these processes with the FtsZ-ring assembly in mycobacteria.

Epidemiological analysis of Mycobacterium tuberculosis strains isolated in Lodz, Poland.

BACKGROUND: Mycobacterium tuberculosis is one of the most dangerous human pathogens. Molecular typing of M. tuberculosis has allowed better control of tuberculosis and, among other benefits, identification of genetic lineages among strains. OBJECTIVE: To test the potential of polymerase chain reaction (PCR) based methods for the epidemiological study of M. tuberculosis strains isolated from patients residing in a single city. DESIGN: We performed spoligotyping, mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing and insertion sequence (IS) 6110 restriction fragment length polymorphism (RFLP) analyses of 234 clinical strains of M. tuberculosis collected over 2 years from the Polish city of Lodz. RESULTS: Spoligotyping analysis revealed 84 spoligotypes with a shared international type and 50 unique spoligotypes. Subtyping via 15- and 19-loci MIRU-VNTR analyses revealed 154 patterns with 117 unique profiles, and 159 patterns with 126 unique profiles, respectively. Spoligotyping combined with MIRU-VNTR 15- and 19 loci analyses revealed 132 and 146 unique profiles, respectively. Overall, 96 strains clustered via MIRU-VNTR typing were used in IS6110-RFLP analysis. Complete congruence of patterns revealed by PCR-based methods was noted for 40 strains, of which 36 were isolated from epidemiologically linked patients. CONCLUSION: The combination of 15-loci MIRU-VNTR typing with spoligotyping is useful for primary analysis of M. tuberculosis strains; however, additional use of MIRU 23 should be considered. Strains clustered by PCR-based methods should be further analysed by IS6110-RFLP typing.

Characterization of CrgA, a new partner of the Mycobacterium tuberculosis peptidoglycan polymerization complexes.

The role(s) in cell division of the Mycobacterium tuberculosis Rv0011c gene product, a homolog of the Streptomyces CrgA protein that is responsible for coordinating growth and cytokinesis in sporogenic aerial hyphae, is largely unknown. We show that an enhanced cyan fluorescent protein-M. tuberculosis CrgA (ECFP-CrgA(MT)) fusion protein is localized to the cell membrane, midcell, and cell pole regions in Mycobacterium smegmatis. Furthermore, the ECFP-CrgA(MT) fusion protein colocalized with FtsZ-enhanced yellow fluorescent protein (EYFP) in M. smegmatis. Bacterial two-hybrid assays indicated strong interactions of M. tuberculosis CrgA with FtsZ, FtsQ, and the class B penicillin-binding proteins, FtsI (PBPB) and PBPA. The midcell localization of CrgA(MT) was severely compromised under conditions of FtsZ depletion, which indicated that CrgA localizes to the midcell region after assembly of the FtsZ ring. M. tuberculosis cells with reduced CrgA levels were elongated and grew more slowly than wild-type cells, which indicated defects in cell division, whereas CrgA overproduction did not show growth defects. A M. smegmatis ΔcrgA strain exhibited a bulged cell morphology, elongated cells with a chain-like phenotype, cells with polar bulbous structures, and a modest growth defect. FtsZ and FtsI levels were not affected in cells producing altered levels of CrgA. Septal and membrane localization of GFP-FtsI was enhanced by CrgA overproduction and was diminished in a ΔcrgA strain, which indicates that one role of CrgA is to promote and/or stabilize FtsI localization. Overall, these data indicate that CrgA is a novel member of the cell division complex in mycobacteria and possibly facilitates septum formation.

[Characteristics of intra-articular injuries of the knee joint in coal miners]. / Charakterystyka uszkodzen wewnatrzstawowych powstalych w nastepstwie przewleklych urazów stawu kolanowego u górników.

This study presents an analysis of chronic knee injuries among coalminers. The aim of this paper was to individuate a relationship between the work conditions in coal mines and the observed pathological changes in the knee joint, as well as to assess the results of treatment. A population of 120 coal miners age ranging from 20 to 46 years (mean age 33.4 years) working in conditions continuously stressing the knee joints was evaluated. It was found that the lower the seam where the miners worked, the greater was the damage to the cartilage. Meniscus injuries were found mainly in miners working in higher seams with smaller load on the knew. It was also found that in this population multiple structures of the knee were injured simultaneously.

[A case history regarding a 14-year old girl with acromio-clavicular dislocation and tear of the coracoclavicular ligament]. / Praca kazuistyczna dotyczaca opisu 14-letniej dziewczynki ze zwichnieciem obojczykowo-barkowym i rozerwaniem wiazadel kruczo-obojczykowych.

A rare injury in children and its surgical treatment is presented. The coraco-acromial ligament was used to restore acromio-clavicular junction. Its acromial end has been transferred to the coracoid tuberosity of the clavicle and placed subperiosteal with 2-point suture fixation. An excellent clinical and radiological result has been achieved.