The two-component system ArlRS is essential for wall teichoic acid glycoswitching in .

is among the leading causes of hospital-acquired infections. Critical to biology and pathogenesis are the cell wall-anchored glycopolymers wall teichoic acids (WTA). Approximately one-third of isolates decorates WTA with a mixture of α1,4- and β1,4--acetylglucosamine (GlcNAc), which requires the dedicated glycosyltransferases TarM and TarS, respectively.

The streptococcal phase-variable type I restriction modification system SsuCC20p dictates the methylome of impacting the transcriptome and virulence in a zebrafish larvae infection model.

Phase variation allows a single strain to produce phenotypic diverse subpopulations. Phase-variable restriction modification (RM) systems are systems that allow for such phase variation via epigenetic regulation of gene expression levels. The phase-variable RM system SsuCC20p was found in multiple streptococcal species and was acquired by an emerging zoonotic lineage of .

Neisseria meningitidis Sibling Small Regulatory RNAs Connect Metabolism with Colonization by Controlling Propionate Use.

Neisseria meningitidis (meningococcus) colonizes the human nasopharynx, primarily as a commensal, but sporadically causing septicemia and meningitis. During colonization and invasion, it encounters different niches with specific nutrient compositions. Small noncoding RNAs (sRNAs) are used to fine-tune expression of genes, allowing adaptation to their physiological differences.

Genetic diversity of wall teichoic acid glycosyltransferases affects immune recognition.

is a leading cause of skin and soft tissue infections and systemic infections. Wall teichoic acids (WTAs) are cell wall-anchored glycopolymers that are important for nasal colonization, phage-mediated horizontal gene transfer, and antibiotic resistance. WTAs consist of a polymerized ribitol phosphate (RboP) chain that can be glycosylated with -acetylglucosamine (GlcNAc) by three glycosyltransferases: TarS, TarM, and TarP.

Meningococcal virulence in zebrafish embryos depends on capsule polysaccharide structure.

Unlabelled: or the meningococcus, can cause devasting diseases such as sepsis and meningitis. Its polysaccharide capsule, on which serogrouping is based, is the most important virulence factor. Non-encapsulated meningococci only rarely cause disease, due to their sensitivity to the host complement system.

ST24: Clonal Strains of One Health Importance Dominate in Australian Horse, Bird and Human Infections.

is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic diversity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24.

Fatal Chlamydia avium Infection in Captive Picazuro Pigeons, the Netherlands.

In 2016, an outbreak of Chlamydia avium infection occurred among Picazuro pigeons (Patagioenas picazuro) living in an aviary in the Netherlands. Molecular typing revealed a unique strain of C. avium.

Multilocus Sequence Typing (MLST) of Chlamydiales.

Developed two decades ago as a molecular method to provide definite characterization of a bacterial isolate, Multilocus Sequence Typing (MLST) is today globally adopted as a universal fine-detailed molecular typing tool and has been applied to numerous pathogenic and nonpathogenic bacterial as well eukaryotic organisms. MLST utilizes DNA sequence of several conserved housekeeping (HK) genes which are assigned an allelic number, which then collectively constitute an allelic profile or sequence type (ST), a "molecular barcode" of the interrogated bacterial strain or a eukaryotic organism. Here, we describe the principles and molecular approaches for generating MLST data for an analysis of a bacteria in the order Chlamydiales, using a Chlamydia pecorum-specific MLST scheme as an example.

Genomic analyses of the Chlamydia trachomatis core genome show an association between chromosomal genome, plasmid type and disease.

Background: Chlamydia trachomatis (Ct) plasmid has been shown to encode genes essential for infection. We evaluated the population structure of Ct using whole-genome sequence data (WGS). In particular, the relationship between the Ct genome, plasmid and disease was investigated.

Asymptomatic infections with highly polymorphic Chlamydia suis are ubiquitous in pigs.

Background: Chlamydia suis is an important, globally distributed, highly prevalent and diverse obligate intracellular pathogen infecting pigs. To investigate the prevalence and genetic diversity of C. suis in China, 2,137 nasal, conjunctival, and rectal swabs as well as whole blood and lung samples of pigs were collected in 19 regions from ten provinces of China in this study.

Sequencing of the variable region of to discriminate between and other streptococcal species.

The vast majority of streptococci colonizing the human upper respiratory tract are commensals, only sporadically implicated in disease. Of these, the most pathogenic is Mitis group member, Phenotypic and genetic similarities between streptococci can cause difficulties in species identification. Using ribosomal S2-gene sequences extracted from whole-genome sequences published from 501 streptococci, we developed a method to identify streptococcal species.

Regulation of cytochrome components by NrrF, a Fur-controlled small noncoding RNA.

NrrF is a small regulatory RNA of the human pathogen . NrrF was previously shown to repress succinate dehydrogenase () under control of the ferric uptake regulator (Fur). Here, we provide evidence that cytochrome , encoded by the polycistronic mRNA , is a NrrF target as well.

The Hfq regulon of .

The conserved RNA-binding protein, Hfq, has multiple regulatory roles within the prokaryotic cell, including promoting stable duplex formation between small RNAs and mRNAs, and thus deletion mutants have pleiotropic phenotypes. Previous proteome and transcriptome studies of have generated limited insight into differential gene expression due to Hfq loss. In this study, reversed-phase liquid chromatography combined with data-independent alternate scanning mass spectrometry (LC-MS) was utilized for rapid high-resolution quantitative proteomic analysis to further elucidate the differentially expressed proteome of a meningococcal deletion mutant.

Streptococcal Adhesin P (SadP) contributes to Streptococcus suis adhesion to the human intestinal epithelium.

Background: Streptococcus suis is a zoonotic pathogen, causing meningitis and septicemia. We previously demonstrated that the gastrointestinal tract (GIT) is an entry site for zoonotic S. suis infection.

Uses Sibling Small Regulatory RNAs To Switch from Cataplerotic to Anaplerotic Metabolism.

(the meningococcus) is primarily a commensal of the human oropharynx that sporadically causes septicemia and meningitis. Meningococci adapt to diverse local host conditions differing in nutrient supply, like the nasopharynx, blood, and cerebrospinal fluid, by changing metabolism and protein repertoire. However, regulatory transcription factors and two-component systems in meningococci involved in adaptation to local nutrient variations are limited.

Genus delineation of Chlamydiales by analysis of the percentage of conserved proteins justifies the reunifying of the genera Chlamydia and Chlamydophila into one single genus Chlamydia.

Many studies have aimed to set up boundaries for the classification and definition of prokaryotic genus and species classification; however, studies that focused on genus-level genomic differences for existing taxonomy systems are limited. Recently, a novel method was described for prokaryotic genus delineation using the percentage of conserved proteins (POCP) between two strains to estimate their evolutionary and phenotypic distance (Qin et al. A proposed genus boundary for the prokaryotes based on genomic insights.