emm typing and validation of provisional M types for group A streptococci.

This report discusses the following issues related to typing of group A streptococci (GAS): The development and use of the 5' emm variable region sequencing (emm typing) in relation to the existing serologic typing system; the designation of emm types in relation to M types; a system for validation of new emm types; criteria for validation of provisional M types to new M-types; a list of reference type cultures for each of the M-type or emm-type strains of GAS; the results of the first culture exchange program for a quality control testing system among the national and World Health Organization collaborating centers for streptococci; and dissemination of new approaches to typing of GAS to the international streptococcal community

Assessment of websites with information on medicines

Objetivo: Identificar sitios web con información sobre medicamentos a través de expertos y evaluar su adecuación a códigos de conducta y las recomendaciones de la Organización Mundial de la Salud. Diseño: Estudio transversal de la adecuación a los criterios, a partir de un cuestionario diseñado ad hoc (efectuado independientemente por dos evaluadores). Los sitios web fueron identificados a partir de la técnica Delphi (35 expertos). Emplazamiento: Sitios web con información sobre medicamentos. Unidad de análisis: 35 sitios web seleccionados por la técnica Delphi. En la tercera ronda se alcanzó un nivel de estabilidad (variabilidad intercuartílica) aceptable (< 0,05). Mediciones principales: Responsabilidad, transparencia y honestidad, autoría de la información, política editorial, protección de datos personales, actualización de la información y accesibilidad. Se realizó un análisis descriptivo del cumplimiento y se estimó el coeficiente kappa para valorar la concordancia entre evaluadores (criterios de Fleiss). Resultados: Destacan con cumplimiento general alto el National Prescribing Service Limited (NPS), PubMed, British Medical Journal, New England Journal of Medicine, Journal of American Medical Association, The Lancet, Fisterra y National Institute for Health and Clinical Excellence. La dimensión de actualización de la información es la que presentó una menor valoración para los diferentes sitios web. Conclusiones: La calidad de los sitios web sobre medicamentos recomendada por expertos es variable. Sin embargo, hay diversos sitios web de cumplimiento alto, que se detallan en el informe.Aims: To identify websites with information on medicines and assess, using experts, their adherence to codes of conduct and recommendations by the WHO. Design: Cross-sectional study based on an ad hoc designed questionnaire (performed independently by 2 reviewers). The websites were identified by the Delphi technique (35 experts). Setting: Websites with information on medicines. Participants: A total of 35 websites selected by the Delphi technique. An acceptable level of stability was achieved in the third round (interquartile variability; <0.05). Main measurements: Responsibility, transparency and honesty, authorship of the information, content review policy, privacy and data protection policies, updated information and accessibility. A descriptive analysis of compliance was carried out and the kappa coefficient was estimated to evaluate the agreement between assessors (Fleiss's Criteria). Results: The National Prescribing Service Limited (NPS), PubMed, British Medical Journal, New England Journal of Medicine, Journal of American Medical Association, The Lancet, Fisterra and National Institute for Health and Clinical Excellence stood out with an overall high fulfilment of the questionnaire. The updated information dimension was the lowest evaluation for the different websites. Conclusions: The quality of the web sites evaluated varied widely. Although there are several websites, which are detailed in the article, with high overall scores

Mass Antibiotic Treatment for Group A Streptococcus Outbreaks in Two Long-Term Care Facilities1

Outbreaks of invasive infections caused by group A β-hemolytic streptococcus (GAS) may occur in long-term care settings and are associated with a high case-fatality rate in debilitated adults. Targeted antibiotic treatment only to residents and staff known to be at specific risk of GAS may be an ineffective outbreak control measure. We describe two institutional outbreaks in which mass antibiotic treatment was used as a control measure. In the first instance, mass treatment was used after targeted antibiotic treatment was not successful. In the second instance, mass treatment was used to control a rapidly evolving outbreak with a high case-fatality rate. Although no further clinical cases were seen after the introduction of mass antibiotic treatment, persistence of the outbreak strain was documented in one institution >1 year after cases had ceased. Strain persistence was associated with the presence of a chronically colonized resident and poor infection control practices

Characterization of anti-drug antibody responses to the T-cell engaging bispecific antibody cibisatamab to understand the impact on exposure

An appropriately designed pharmacokinetic (PK) assay that is sensitive for anti-drug antibody (ADA) impact on relevant exposure is an alternative strategy to understand the neutralizing potential of ADAs. However, guidance on how to develop such PK assays and how to confirm the functional ADA impact on exposure is missing. Here, the PK assay of a T-cell-engaging bispecific antibody, cibisatamab, was developed based on its mechanism of action (MoA). Using critical monoclonal anti-idiotypic (anti-ID) antibody positive controls as ADA surrogates, the impact on exposure was evaluated pre-clinically. In a phase I clinical trial (NCT02324257), initial data suggest that the combination of ADA and PK assays for correlation of the ADA response with cibisatamab exposure. To understand the neutralizing potential of patient-derived ADAs on drug activity, advanced ADA characterization has been performed. Structural binding analysis of ADAs to antibody domains of the drug and its impact on targeting were assessed. For this purpose, relevant patient ADA binding features were identified and compared with the specific monoclonal anti-ID antibody-positive controls. Comparable results of target binding inhibition and similar impacts on exposure suggest that the observed reduction of Cmax and Ctrough levels in patients is caused by the neutralizing potential of ADAs and allows a correlation between ADA response and loss of exposure. Therefore, the described study provides important functional aspects for the development of an appropriately designed PK assay for bispecific antibodies as an alternative option towards understanding the neutralizing ADA impact on exposure

Inference of Antibiotic Resistance and Virulence among Diverse Group A Streptococcus Strains Using emm Sequencing and Multilocus Genotyping Methods

typing (direct sequencing of the genomic segment coding for the antigenic portion of the M protein) or by multilocus genotyping methods. Phenotype analysis, including critical AbR typing, is generally achieved by much slower and more laborious direct culture-based methods. type and the associated AbR and virulence phenotypes. types

Enterococcal colonization of infants in a neonatal intensive care unit: associated predictors, risk factors and seasonal patterns

<p>Abstract</p> <p>Background</p> <p>During and shortly after birth, newborn infants are colonized with enterococci. This study analyzes predictors for early enterococcal colonization of infants in a neonatal intensive care unit and describes risk factors associated with multidrugresistant enterococci colonization and its seasonal patterns.</p> <p>Methods</p> <p>Over a 12-month period, we performed a prospective epidemiological study in 274 infants admitted to a neonatal intensive care unit. On the first day of life, we compared infants with enterococcal isolates detected in meconium or body cultures to those without. We then tested the association of enterococcal colonization with peripartal predictors/risk factors by using bivariate and multivariate statistical methods.</p> <p>Results</p> <p>Twenty-three percent of the infants were colonized with enterococci. The three most common enterococcal species were <it>E. faecium </it>(48% of isolates), <it>E. casseliflavus </it>(25%) and <it>E. faecalis </it>(13%). Fifty-seven percent of the enterococci found were resistant to three of five antibiotic classes, but no vancomycin-resistant isolates were observed. During winter/spring months, the number of enterococci and multidrug-resistant enterococci were higher than in summer/fall months (p = 0.002 and p < 0.0001, respectively). With respect to enterococcal colonization on the first day of life, predictors were prematurity (p = 0.043) and low birth weight (p = 0.011). With respect to colonization with multidrug-resistant enterococci, risk factors were prematurity (p = 0.0006), low birth weight (p < 0.0001) and prepartal antibiotic treatment (p = 0.019). Using logistic regression, we determined that gestational age was the only parameter significantly correlated with multidrug-resistant enterococci colonization. No infection with enterococci or multidrugresistant enterococci in the infants was detected. The outcome of infants with and without enterococcal colonization was the same with respect to death, necrotizing enterocolitis, intracerebral hemorrhage and bronchopulmonary dysplasia.</p> <p>Conclusion</p> <p>In neonatal intensive care units, an infant's susceptibility to early colonization with enterococci in general, and his or her risk for colonization with multidrug-resistant enterococci in particular, is increased in preterm newborns, especially during the winter/spring months. The prepartal use of antibiotics with no known activity against enterococci appears to increase the risk for colonization with multidrug-resistant enterococci.</p

Population Genetics of Streptococcus dysgalactiae Subspecies equisimilis Reveals Widely Dispersed Clones and Extensive Recombination

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging global pathogen that can colonize and infect humans. Although most SDSE isolates possess the Lancefield group G carbohydrate, a significant minority have the group C carbohydrate. Isolates are further sub-typed on the basis of differences within the emm gene. To gain a better understanding of their molecular epidemiology and evolutionary relationships, multilocus sequence typing (MLST) analysis was performed on SDSE isolates collected from Australia, Europe and North America.The 178 SDSE isolates, representing 37 emm types, segregate into 80 distinct sequence types (STs) that form 17 clonal complexes (CCs). Eight STs recovered from all three continents account for >50% of the isolates. Thus, a small number of STs are highly prevalent and have a wide geographic distribution. Both ST and CC strongly correlate with group carbohydrate. In contrast, eleven STs were associated with >1 emm type, suggestive of recombinational replacements involving the emm gene; furthermore, 35% of the emm types are associated with genetically distant STs. Data also reveal a history of extensive inter- and intra-species recombination involving the housekeeping genes used for MLST. Sequence analysis of single locus variants identified through goeBURST indicates that genetic change mediated by recombination occurred approximately 4.4 times more frequently than by point mutation.A few genetic lineages with an intercontinental distribution dominate among SDSE causing infections in humans. The distinction between group C and G isolates reflects recent evolution, and no long-term genetic isolation between them was found. Lateral gene transfer and recombination involving housekeeping genes and the emm gene are important mechanisms driving genetic variability in the SDSE population

Bacteraemia in asymptomatic human subjects

The common occurrence of post-tooth extraction bacteraemia provides a convenient model system to evaluate techniques which demonstrate the magnitude of the bacteraemia. The system used continuous anaerobiosis and membrane filter recovery to quantitate bacteraemia. 19 of 22 pre-extraction blood samples and 20 of 22 post-extraction samples from hospitalized patients had one or more colonies per 5 ml of blood. Colonies recovered averaged 7.3 per 5 ml of blood for the pre-extraction samples and 10.7 for the post-extraction samples. 86 per cent of the pre-extraction bloods contained bacteria. 30 of 42 pre-extraction and 32 of 41 post-extraction samples from asymptomatic patients having teeth extracted had a bacteraemia which averaged about 5 colonies per 5 ml of blood. Subsequent studies were concerned with the prevalance of detectable bacteraemia. In one series of presumably healthy blood bank donors, blood from 16 of 20 donors was positive for bacteria, with an average recovery of 11 organisms per 5 ml of blood. In a second series, in which multiple samples were tested, 18 of 29 donors were positive with an average recovery of 2 organisms per 5 ml of blood. The taxonomic characteristics of the isolates suggested that they could have originated from the intestine (Streptococcus faecalis), the skin (Propionibacterium acnes and Staphylococcus epidermidis) and the oral cavity (Actinomyces viscosus).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23022/1/0000591.pd

Contribution of Exogenous Genetic Elements to the Group A Streptococcus Metagenome

Variation in gene content among strains of a bacterial species contributes to biomedically relevant differences in phenotypes such as virulence and antimicrobial resistance. Group A Streptococcus (GAS) causes a diverse array of human infections and sequelae, and exhibits a complex pathogenic behavior. To enhance our understanding of genotype-phenotype relationships in this important pathogen, we determined the complete genome sequences of four GAS strains expressing M protein serotypes (M2, M4, and 2 M12) that commonly cause noninvasive and invasive infections. These sequences were compared with eight previously determined GAS genomes and regions of variably present gene content were assessed. Consistent with the previously determined genomes, each of the new genomes is ∼1.9 Mb in size, with ∼10% of the gene content of each encoded on variably present exogenous genetic elements. Like the other GAS genomes, these four genomes are polylysogenic and prophage encode the majority of the variably present gene content of each. In contrast to most of the previously determined genomes, multiple exogenous integrated conjugative elements (ICEs) with characteristics of conjugative transposons and plasmids are present in these new genomes. Cumulatively, 242 new GAS metagenome genes were identified that were not present in the previously sequenced genomes. Importantly, ICEs accounted for 41% of the new GAS metagenome gene content identified in these four genomes. Two large ICEs, designated 2096-RD.2 (63 kb) and 10750-RD.2 (49 kb), have multiple genes encoding resistance to antimicrobial agents, including tetracycline and erythromycin, respectively. Also resident on these ICEs are three genes encoding inferred extracellular proteins of unknown function, including a predicted cell surface protein that is only present in the genome of the serotype M12 strain cultured from a patient with acute poststreptococcal glomerulonephritis. The data provide new information about the GAS metagenome and will assist studies of pathogenesis, antimicrobial resistance, and population genomics