Capsular Type, Sequence Type and Microbial Resistance Factors Impact on DNase Activity of Strains from Human and Bovine Origin.

Extracellular deoxyribonucleases (DNases) contribute to the spread of pathogenic bacteria through the evasion from host innate immunity. Our main objective was to evaluate the production of extracellular DNases by human and bovine clinical strains and perform a correlation of genetic lineages and DNase activity with capsular type, genetic determinants, clinical origin (colonization and infection), and host (human or bovine). DNase activity was evaluated by qualitative and quantitative assays for a collection of 406 human ( = 285) and bovine ( = 121) strains.

Chromosomally and Extrachromosomally Mediated High-Level Gentamicin Resistance in Streptococcus agalactiae.

Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis in neonates. The rate of invasive GBS disease in nonpregnant adults also continues to climb. Aminoglycosides alone have little or no effect on GBS, but synergistic killing with penicillin has been shown in vitro.

Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production.

Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level.

Accuracy of prenatal culture in predicting intrapartum group B streptococcus colonization status.

Objective: To evaluate the positive predictive value (PPV) of group B Streptococcus (GBS) cultures at 35-37 weeks of gestation relative to GBS colonization status at delivery.

Methods: Rectovaginal swabs from 221 women at labor in four Lisbon hospitals were collected for GBS screening according to the CDC guidelines.

Results: The PPV was 24.

Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis.

Streptococcus agalactiae (Group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (Group C Streptococcus, GCS) and Streptococcus uberis are relevant mastitis pathogens, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production. The aims of this study were the evaluation of antimicrobial drug resistance patterns, particularly important for streptococcal mastitis control and the identification of strain molecular features.

Molecular epidemiology of group B streptococcal meningitis in children beyond the neonatal period from Angola.

Streptococcus agalactiae is a major pathogen of neonates and immunocompromised adults. Prior studies have demonstrated that, beyond the neonatal period, S. agalactiae rarely causes invasive infections in children.

Genotypes and antimicrobial-resistant phenotypes of Neisseria gonorrhoeae in Portugal (2004-2009).

Objectives: To determine the antibiotic phenotype and MAST-genotype distribution of Neisseria gonorrhoeae isolates in Portugal between 2004 and 2009, and to evaluate specific associations between MAST-genotypes and sexual orientation, age and antibiotic resistance.

Methods: A total of 236 N gonorrhoeae isolates were typed through N gonorrhoeae multiantigen sequence typing (NG-MAST). The degree of polymorphism and the phylogenetic relatedness among NG-MAST sequence types (STs) were evaluated with MEGA4 software on concatenated sequences of por and tbpb alleles.

Evolutionary dynamics of ompA, the gene encoding the Chlamydia trachomatis key antigen.

Chlamydia trachomatis is the trachoma agent and causes most bacterial sexually transmitted infections worldwide. Its major outer membrane protein (MOMP) is a well-known porin and adhesin and is the dominant antigen. So far, investigation of MOMP variability has been focused mainly on molecular epidemiological surveys.

Lymphogranuloma venereum in Portugal: unusual events and new variants during 2007.

Background: Several European countries identified an ongoing LGV outbreak, particularly among men who have sex with men (MSM). In Portugal, no particular surveillance measures were launched. Nonetheless, circulating LGV strains could eventually be detected through the routine Chlamydia trachomatis ompA genotyping procedure held in the Portuguese National Institute of Health (NIH).

Comparative expression profiling of the Chlamydia trachomatis pmp gene family for clinical and reference strains.

Background: Chlamydia trachomatis, an obligate intracellular pathogen, is a leading worldwide cause of ocular and urogenital diseases. Advances have been made in our understanding of the nine-member polymorphic membrane protein (Pmp) gene (pmp) family of C. trachomatis.

Evolution of Chlamydia trachomatis diversity occurs by widespread interstrain recombination involving hotspots.

Chlamydia trachomatis is an obligate intracellular bacterium of major public health significance, infecting over one-tenth of the world's population and causing blindness and infertility in millions. Mounting evidence supports recombination as a key source of genetic diversity among free-living bacteria. Previous research shows that intracellular bacteria such as Chlamydiaceae may also undergo recombination but whether this plays a significant evolutionary role has not been determined.

Polymorphisms in the nine polymorphic membrane proteins of Chlamydia trachomatis across all serovars: evidence for serovar Da recombination and correlation with tissue tropism.

Chlamydia trachomatis is an intracellular bacterium responsible for ocular, respiratory, and sexually transmitted diseases. The genome contains a nine-member polymorphic membrane protein (Pmp) family unique to members of the order Chlamydiales. Genomic and molecular analyses were performed for the entire pmp gene family for the 18 reference serological variants (serovars) and genovariant Ja to identify specific gene and protein regions that differentiate chlamydial disease groups.