Recombinational exchange of M-fibril and T-pilus genes generates extensive cell surface diversity in the global group A population.

Among genes present in all group A streptococci (GAS), those encoding M-fibril and T-pilus proteins display the highest levels of sequence diversity, giving rise to the two primary serological typing schemes historically used to define strain. A new genotyping scheme for the pilin adhesin and backbone genes is developed and, when combined with typing, provides an account of the global GAS strain population. Cluster analysis based on nucleotide sequence similarity assigns most T-serotypes to discrete pilin backbone sequence clusters, yet the established T-types correspond to only half the clusters.

Pasteurized Akkermansia muciniphila reduces periodontal and systemic inflammation induced by Porphyromonas gingivalis in lean and obese mice.

Aim: The aim of this study was to evaluate the effect of the administration of pasteurized Akkermansia muciniphila and Amuc_1100 on periodontal destruction in lean and obese mice and to determine the impact of the mode of administration.

Materials And Methods: Porphyromonas gingivalis-associated experimental periodontitis was induced in lean and obese mice. After 3 weeks, live, pasteurized A.

Akkermansia muciniphila and Its Pili-Like Protein Amuc_1100 Modulate Macrophage Polarization in Experimental Periodontitis.

Periodontitis is a chronic inflammatory disease triggered by dysbiosis of the oral microbiome. is strongly implicated in periodontal inflammation, gingival tissue destruction, and alveolar bone loss through sustained exacerbation of the host response. Recently, the use of other bacterial species, such as , has been suggested to counteract inflammation elicited by In this study, the effects of and its pili-like protein Amuc_1100 on macrophage polarization during infection were evaluated in a murine model of experimental periodontitis.

Mapping of internal monophosphate 5' ends of Bacillus subtilis messenger RNAs and ribosomal RNAs in wild-type and ribonuclease-mutant strains.

The recent findings that the narrow-specificity endoribonuclease RNase III and the 5' exonuclease RNase J1 are not essential in the Gram-positive model organism,Bacillus subtilis, facilitated a global analysis of internal 5' ends that are generated or acted upon by these enzymes. An RNA-Seq protocol known as PARE (Parallel Analysis of RNA Ends) was used to capture 5' monophosphorylated RNA ends in ribonuclease wild-type and mutant strains. Comparison of PARE peaks in strains with RNase III present or absent showed that, in addition to its well-known role in ribosomal (rRNA) processing, many coding sequences and intergenic regions appeared to be direct targets of RNase III.

Small stable RNA maturation and turnover in Bacillus subtilis.

Stable RNA maturation is a key process in the generation of functional RNAs, and failure to correctly process these RNAs can lead to their elimination through quality control mechanisms. Studies of the maturation pathways of ribosomal RNA and transfer RNA in Bacillus subtilis showed they were radically different from Escherichia coli and led to the identification of new B. subtilis-specific enzymes.

CTnDOT integrase interactions with attachment site DNA and control of directionality of the recombination reaction.

IntDOT is a tyrosine recombinase encoded by the conjugative transposon CTnDOT. The core binding (CB) and catalytic (CAT) domains of IntDOT interact with core-type sites adjacent to the regions of strand exchange, while the N-terminal arm binding (N) domain interacts with arm-type sites distal to the core. Previous footprinting experiments identified five arm-type sites, but how the arm-type sites participate in the integration and excision of CTnDOT was not known.

Multiple small RNAs identified in Mycobacterium bovis BCG are also expressed in Mycobacterium tuberculosis and Mycobacterium smegmatis.

Tuberculosis (TB) is a major global health problem, infecting millions of people each year. The causative agent of TB, Mycobacterium tuberculosis, is one of the world's most ancient and successful pathogens. However, until recently, no work on small regulatory RNAs had been performed in this organism.

Interdisciplinary bacteria and phages.

A report of the meeting 'Molecular Genetics of Bacteria and Phages', Cold Spring Harbor, USA, 20-24 August 2008.

IntDOT interactions with core- and arm-type sites of the conjugative transposon CTnDOT.

CTnDOT is a Bacteroides conjugative transposon (CTn) that has facilitated the spread of antibiotic resistances among bacteria in the human gut in recent years. Although the integrase encoded by CTnDOT (IntDOT) carries the C-terminal set of conserved amino acids that is characteristic of the tyrosine family of recombinases, the reaction it catalyzes involves a novel step that creates a short region of heterology at the joined ends of the element during recombination. Also, in contrast to tyrosine recombinases, IntDOT catalyzes a reaction that is not site specific.

In vitro analysis of sequence requirements for the excision reaction of the Bacteroides conjugative transposon, CTnDOT.

CTnDOT, a Bacteroides conjugative transposon (CTn), initiates its transfer by excising to form a circular intermediate. This process has been shown to be complex, involving an unusual DNA intermediate with a short region of heterology and several CTn-encoded proteins. No information was available, however, about the sizes or sequence requirements of the att sites (attL and attR) at the ends of the integrated element where the processing occurs during excision.

Factors required in vitro for excision of the Bacteroides conjugative transposon, CTnDOT.

Four genes have been found to be essential for excision of the Bacteroides conjugative transposon CTnDOT in vivo: intDOT, orf2c, orf2d, and exc. The intDOT gene encodes an integrase that is essential for integration and excision. The function of the other genes is still uncertain.

Endonuclease cleavage of messenger RNA in Bacillus subtilis.

A deletion derivative of the ermC gene was constructed that expresses a 254-nucleotide mRNA. The small size of this mRNA facilitated the detection of processing products that did not differ greatly in size from the full-length transcript. In the presence of erythromycin, which induces ribosome stalling near the 5' end of ermC mRNA, the 254-nucleotide mRNA was cleaved endonucleolytically at the site of ribosome stalling.