Clonal expansion of a virulent Streptococcus suis serotype 9 lineage distinguishable from carriage subpopulations.

Streptococcus suis is a porcine pathogen, causing severe invasive infections. S. suis serotype 9 is increasingly causing disease in Dutch and Chinese pig herds, but it is unknown whether all serotype 9 isolates are equally virulent and markers that can identify virulent strains are not available.

In vivo transcriptomes of Streptococcus suis reveal genes required for niche-specific adaptation and pathogenesis.

Streptococcus suis is a Gram-positive bacterium and a zoonotic pathogen residing in the nasopharynx or the gastrointestinal tract of pigs with a potential of causing life-threatening invasive disease. It is endemic in the porcine production industry worldwide, and it is also an emerging human pathogen. After invasion, the pathogen adapts to cause bacteremia and disseminates to different organs including the brain.

Genomic and functional characterisation of IncX3 plasmids encoding bla in Escherichia coli from human and animal origin.

The bla β-lactamase gene is one of the most prevalent genes conferring resistance to extended-spectrum β-lactams in Enterobacteriaceae disseminating within and between reservoirs, mostly via plasmid-mediated horizontal gene transfer. Yet, studies regarding the biology of plasmids encoding bla are very limited. In this study, we revealed the emergence of IncX3 plasmids alongside IncI1α/γ in bla in animal-related Escherichia coli isolates.

Genome Plasticity and Polymorphisms in Critical Genes Correlate with Increased Virulence of Dutch Outbreak-Related Strains.

is an obligate intracellular bacterium and the etiological agent of Q fever. During 2007-2010 the largest Q fever outbreak ever reported occurred in The Netherlands. It is anticipated that strains from this outbreak demonstrated an increased zoonotic potential as more than 40,000 individuals were assumed to be infected.

Simultaneous Quantification and Differentiation of Streptococcus suis Serotypes 2 and 9 by Quantitative Real-Time PCR, Evaluated in Tonsillar and Nasal Samples of Pigs.

Invasive Streptococcus suis (S. suis) infections in pigs are often associated with serotypes 2 and 9. Mucosal sites of healthy pigs can be colonized with these serotypes, often multiple serotypes per pig.

Invasive pneumococcal disease leads to activation and hyperreactivity of platelets.

Using a novel porcine model of intravenous Streptococcus pneumoniae infection, we showed that invasive pneumococcal infections induce marked platelet activation and hyperreactivity. This may contribute to the vascular complications seen in pneumococcal infection.

Pneumococcal colonization and invasive disease studied in a porcine model.

Background: Streptococcus pneumoniae, a Gram-positive bacterium carried in the human nasopharynx, is an important human pathogen causing mild diseases such as otitis media and sinusitis as well as severe diseases including pneumonia, meningitis and sepsis. There is a strong resemblance between the anatomy, immunology and physiology of the pig and human species. Furthermore, there are striking similarities between S.

First Complete Genome Sequence of the Dutch Veterinary Coxiella burnetii Strain NL3262, Originating from the Largest Global Q Fever Outbreak, and Draft Genome Sequence of Its Epidemiologically Linked Chronic Human Isolate NLhu3345937.

The largest global Q fever outbreak occurred in The Netherlands during 2007 to 2010. Goats and sheep were identified as the major sources of disease. Here, we report the first complete genome sequence of ITALIC! Coxiella burnetiigoat outbreak strain NL3262 and that of an epidemiologically linked chronic human strain, both having the outbreak-related ITALIC! CbNL01multilocus variable-number tandem-repeat analysis (MLVA) genotype.

Major differential gene regulation in Coxiella burnetii between in vivo and in vitro cultivation models.

Background: Coxiella burnetii is the causative agent of the zoonotic disease Q fever. As it is an intracellular pathogen, infection by C. burnetii requires adaptation to its eukaryotic host and intracellular environment.

Characterization of epidemic IncI1-Iγ plasmids harboring ambler class A and C genes in Escherichia coli and Salmonella enterica from animals and humans.

The aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained from Escherichia coli and Salmonella enterica isolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms.

IncI shufflons: Assembly issues in the next-generation sequencing era.

The shufflon is a site-specific recombination system first identified in the IncI1 plasmid R64. The R64 shufflon consists of four segments, separated by short repeats, which are rearranged and inverted by the recombinase protein Rci, generating diversity in the C-terminal end of the PilV protein. PilV is the tip adhesin of the thin pilus structure involved in bacterial conjugation and may play a role in determining recipient cell specificity during liquid mating.

Cell-free propagation of Coxiella burnetii does not affect its relative virulence.

Q fever is caused by the obligate intracellular bacterium Coxiella burnetii. In vitro growth of the bacterium is usually limited to viable eukaryotic host cells imposing experimental constraints for molecular studies, such as the identification and characterisation of major virulence factors. Studies of pathogenicity may benefit from the recent development of an extracellular growth medium for C.

Host-pathogen Interaction at the Intestinal Mucosa Correlates With Zoonotic Potential of Streptococcus suis.

Background: Streptococcus suis has emerged as an important cause of bacterial meningitis in adults. The ingestion of undercooked pork is a risk factor for human S. suis serotype 2 (SS2) infection.

A naturally occurring nucleotide polymorphism in the orf2/folc promoter is associated with Streptococcus suis virulence.

Background: Streptococcus suis is a major problem in the swine industry causing meningitis, arthritis and pericarditis in piglets. Pathogenesis of S. suis is poorly understood.

Complete Genome Sequences of IncI1 Plasmids Carrying Extended-Spectrum β-Lactamase Genes.

Extended spectrum beta-lactamases (ESBLs) confer resistance to clinically relevant antibiotics. Often, the resistance genes are carried by conjugative plasmids which are responsible for dissemination. Five IncI1 plasmids carrying ESBLs from commensal and clinical Escherichia coli isolates were completely sequenced and annotated along with a non-ESBL carrying IncI1 plasmid.

Control of competence for DNA transformation in streptococcus suis by genetically transferable pherotypes.

Here we show that S. suis, a major bacterial pathogen of pigs and emerging pathogen in humans responds to a peptide pheromone by developing competence for DNA transformation. This species does not fall within any of the phylogenetic clusters of streptococci previously shown to regulate competence via peptide pheromones suggesting that more species of streptococci may be naturally competent.

Latest developments on Streptococcus suis: an emerging zoonotic pathogen: part 2.

First International Workshop on Streptococcus suis, Beijing, China, 12-13 August 2013. This second and final chapter of the report on the First International Workshop on Streptococcus suis follows on from Part 1, published in the April 2014, volume 9, issue 4 of Future Microbiology. S.

Latest developments on Streptococcus suis: an emerging zoonotic pathogen: part 1.

First International Workshop on Streptococcus suis, Beijing, China, 12-13 August 2013 The first international workshop on Streptococcus suis, which is an important swine pathogen and emerging zoonotic agent, took place in Beijing, jointly organized by the Faculty of Veterinary Medicine, University of Montreal, Canada and the National Institute for Communicable Disease Control and Prevention, China CDC. The aim of the meeting was to gather together, for the first time, more than 80 researchers working on S. suis, from countries including China, Canada, Japan, The Netherlands, Germany, Thailand, the UK and Vietnam.

Carbohydrate availability regulates virulence gene expression in Streptococcus suis.

Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans.

Presence of ESBL/AmpC-producing Escherichia coli in the broiler production pyramid: a descriptive study.

Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E.

Comparative genomic analysis of twelve Streptococcus suis (pro)phages.

Streptococcus suis (S. suis) is an important pathogen that can carry prophages. Here we present a comparative genomic analysis of twelve (pro)phages identified in the genomes of S.

Early host response in the mammary gland after experimental Streptococcus uberis challenge in heifers.

Streptococcus uberis is a highly prevalent causative agent of bovine mastitis, which leads to large economic losses in the dairy industry. The aim of this study was to examine the host response during acute inflammation after experimental challenge with capsulated Strep. uberis.

Complete Genome Sequence of the Streptococcus suis Temperate Bacteriophage ϕNJ2.

Streptococcus suis is an important cause of meningitis, arthritis, and sudden death in young piglets and of meningitis in humans. A novel temperate S. suis-specific bacteriophage (ϕNJ2) was identified.

Extended-spectrum-β-lactamase- and AmpC-β-lactamase-producing Escherichia coli in Dutch broilers and broiler farmers.

Objectives: The aim of this study was to establish the prevalence of extended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase-producing Escherichia coli at Dutch broiler farms and in farmers and to compare ESBL/AmpC-producing isolates from farmers and their animals.

Methods: Twenty-five to 41 cloacal swabs collected from broilers at each of 26 farms and 18 faecal samples from 18 broiler farmers were analysed for determination of the presence of ESBL/AmpC-producing E. coli.