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Objectives Streptococcus pyogenes or group A streptococcus (GAS) is a human specific pathogen that annually infects over 700 million individuals. GAS strains of type emm28 are an abundant cause of invasive infections in Europe and North America. Methods We conducted a population-based study on bacteraemic emm28 GAS cases in Finland, from 1995 to 2015. Whole-genome sequencing (WGS) was used to genetically characterize the bacterial isolates. Bayesian analysis of the population structure was used to define genetic clades. Register-linkage analysis was performed to test for association of emm28 GAS with delivery- or postpartum-related infections. A genome-wide association study was used to search for DNA sequences associated with delivery or puerperal infections. Results Among 3060 bacteraemic cases reported during the study period, 714 were caused by emm28. Women comprised a majority of cases (59 %, 422/714), and were significantly over-represented (84.4 %, 162/192, p < 0.0001) among cases in the childbearing age group (20–40 years). Register-linkage analysis revealed strong association (p < 0.0001) of emm28 bacteraemias with delivery and puerperium. In this register-linkage analysis, 120 women with GAS bacteraemia were identified and linked to delivery, infections during delivery or puerperium time. Among these the proportion of cases caused by emm28 was significantly higher than any other emm type (55.8%, 67/120, p < 0.0001). Among the four genetic subclades identified, SC1B has dominated among the bacteraemic cases since 2000. Altogether 620 of 653 (94.9%) isolates belonged to SC1B. No specific sequence or genetic clade was found nonrandomly associated with delivery or puerperal infections. Conclusions Women of childbearing age were significantly overrepresented among bacteraemic emm28 GAS cases, and in particular were strongly associated with delivery and puerperium cases over the 21 years studied. The molecular mechanisms behind these associations are unclear and warrant further investigation.

Recently two related Streptococcus pyogenes strains with reduced susceptibility to ampicillin, amoxicillin and cefotaxime, antibiotics commonly used to treat S. pyogenes infections were reported. The two strains had the same nonsynonymous (amino acid-substituting) mutation in the pbp2x gene encoding penicillin-binding protein 2X (PBP2X). This concerning report led us to investigate our library of 7,025 genome sequences of type emm1, emm28, and emm89 S. pyogenes clinical strains recovered from intercontinental sources for mutations in pbp2x. We identified 137 strains that combined had 37 nonsynonymous mutations in 36 codons in pbp2x. Although to a lesser magnitude than the two previously published isolates, many of our strains had decreased susceptibility in vitro to multiple beta-lactam antibiotics. Many pbp2x mutations were found only in single strains, but 16 groups of two or more isolates of the same emm type had an identical amino acid replacement. Phylogenetic analysis showed that with one exception, strains of the same emm type with the same amino acid replacement were clonally related by descent. This finding indicates that strains with some amino acid changes in PBP2X can successfully spread to new human hosts and cause invasive infections. Mapping of the amino acid changes onto a three-dimensional structure of the related Streptococcus pneumoniae PBP2X suggests that some substitutions are located in regions functionally important in related pathogenic bacterial species. Decreased beta-lactam susceptibility is geographically widespread in strains of numerically common emm gene subtypes. Enhanced surveillance and further epidemiological and molecular genetic study of this potential emergent antimicrobial problem are warranted.

International audience; Background: In an era of antibiotic resistance, medical students must be prepared to prescribe antibiotics responsibly.Objectives: To assess self-reported preparedness among final-year medical students at European universities, using a comprehensive set of topics related to prudent antibiotic use.Methods: We conducted a cross-sectional, multicentre, web-based survey. All medical-degree students in their final year of studies at European universities were eligible to participate. A preparedness score was calculated for each student and mean scores were compared at medical school and country levels. Comparisons were made with national-level data on resistance among four common bacterial pathogens.Results: In total, 7328 responses were included from 179/296 eligible medical schools in 29/29 countries. Students felt at least sufficiently prepared on a mean of 71.2% of topics assessed, ranging from 54.8% (Portugal) to 84.8% (Latvia). The proportion of students wanting more education on prudent antibiotic use or general antibiotic use ranged from 20.3% (Sweden) to 94.3% (Slovakia), with a mean of 66.1%, and was strongly inversely correlated with preparedness scores (Spearman's ρ = -0.72, n = 29, P < 0.001). Higher prevalence rates of antibiotic-non-susceptible bacteria were associated with lower preparedness scores and higher self-reported needs for further education (P < 0.01).Conclusions: Most final-year European medical students feel they still need more education on antibiotic use for their future practice as junior doctors. Patterns of preparedness on specific topics were identified, were highly consistent across countries, and correlated with both perceived need for further education and levels of antibiotic resistance among common bacteria.

Colistin resistance mediated by mobile mcr‐1 gene has raised concern during the last years. After steep increase in mcr‐1 reports, other mcr‐gene variants (mcr‐2 to mcr‐5) have been revealed as well. In 2016, a clinical study was conducted on asymptomatic stool carriage of extended spectrum beta‐lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae among Finnish adults. All suspected ESBL producing bacterial isolates were first tested by phenotypic ESBL‐confirmation methods, and then further analyzed with whole genome sequencing to identify the resistance genes. We found one study subject carrying a colistin resistant E. coli with a transferrable mcr‐1 gene. This multi‐drug resistant isolate, although initially suspected to be an ESBL producer, did not carry any ESBL genes, but was proven to carry several other resistance genes by using whole genome sequencing. Sequence type was ST93. The mcr‐1 gene was connected to IncX4 plasmid which suggests that the colistin resistance gene locates in the respective plasmid. Here, we report the finding of a mcr‐1 harboring human E. coli isolate from Finland. Clinical antimicrobial resistance (AMR) rates are low in Finland, and mobile colistin resistance has not been reported previously. This highlights the importance of AMR surveillance also in populations with low levels of resistance.

A-streptokokin aiheuttama tautikirjo ulottuu lieväasteisista nielutulehduksesta vakaviin yleisinfektioihin. Nielu- ja ihoinfektiot aiheuttavat huomattavan tautitaakan. ?A-streptokokki tarttuu kosketus- ja pisaratartunta oireettomasta kantajasta ja sairastuneesta henkilöstä, mutta myös kosketuspintojen ja elintarvikkeiden välityksellä. ?Perheissä ja laitosolosuhteissa A-ryhmän streptokokki aiheuttaa epidemioita, joissa sairastuneilla esiintyy nieluinfektiota, tulirokkoa, perianaali-infektiota tai märkärupea. ?Avohoitoepidemiaa epäiltäessä otetaan yhteys kunnan tartuntataudeista vastaavaan lääkäriin ja epidemia-kriteerien täyttyessä pyritään mahdollisimman samanaikaiseen näytteidenottoon ja viljelypositiivisten -henkilöiden mikrobilääkitykseen. ?Invasiiviset A-streptokokki-infektiot ovat harvinaisia. Hoitoon liittyvän invasiivisen A-streptokokki-infektion havaitseminen johtaa aina epidemiaselvitykseen