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Shigella are human-adapted Escherichia coli that have gained the ability to invade the human gut mucosa and cause dysentery, spreading efficiently via low-dose fecal-oral transmission. Historically, S. sonnei has been predominantly responsible for dysentery in developed countries but is now emerging as a problem in the developing world, seeming to replace the more diverse Shigella flexneri in areas undergoing economic development and improvements in water quality. Classical approaches have shown that S. sonnei is genetically conserved and clonal. We report here whole-genome sequencing of 132 globally distributed isolates. Our phylogenetic analysis shows that the current S. sonnei population descends from a common ancestor that existed less than 500 years ago and that diversified into several distinct lineages with unique characteristics. Our analysis suggests that the majority of this diversification occurred in Europe and was followed by more recent establishment of local pathogen populations on other continents, predominantly due to the pandemic spread of a single, rapidly evolving, multidrug-resistant lineage. [ABSTRACT FROM AUTHOR]

A survey of virus vector trichodorid nematodes was carried out in the central and northern regions of Portugal. Morphobiometric identification showed the presence of trichodorid species previously reported from Portugal, except for Paratrichodorus porosus, which is reported for the first time in Continental Europe. Small subunit ribosomal DNA (SSU rDNA) sequences of ten different species occurring in Portugal were obtained and a phylogenetic analysis based on their alignment was performed to infer relationships among the different Portuguese trichodorid species and three non-indigenous populations (Nanidorus minor, P. allius and P. teres). The resulting phylogenetic tree is in agreement with the currently accepted classification for Trichodoridae, except for Nanidorus, which clusters together with Trichodorus species, while the genera Paratrichodorus and Trichodorus appear as two distinct groups. A better understanding of the generic groupings in the family Trichodoridae was found. Based on the new molecular analyses we herein accept Nanidorus as a valid genus. [ABSTRACT FROM AUTHOR]

Background: Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain. Methods and Findings: We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted. Conclusions: Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe. [ABSTRACT FROM AUTHOR]

The BSAC Standing Committee on Antimicrobial Susceptibility Testing is one of several European national breakpoint committees that agreed in 2002 to harmonize clinical MIC breakpoints. The process of harmonization has since been completed for commonly used agents, and breakpoints for new agents have been set by EUCAST in accordance with a procedure defined by the EMA. EUCAST breakpoints have now been adopted by a large majority of laboratories in Europe. BSAC implemented the EUCAST breakpoints in its own disc diffusion susceptibility testing method as harmonized breakpoints were agreed to over the years. Since the development of the EUCAST disc diffusion method, several countries with their own disc diffusion methods have switched to the EUCAST method, and BSAC will replace support of its own disc diffusion method with support for the EUCAST method from January 2016. The EUCAST breakpoints are also available in automated systems. The harmonized breakpoints and methods will help to avoid different reports of susceptibility for the same isolate in different countries and enable more reliable comparison of resistance rates in surveillance studies in different countries. [ABSTRACT FROM AUTHOR]

Harmonization of antimicrobial susceptibility testing breakpoints across Europe has resulted in the reintroduction of the intermediate susceptibility categorization into the BSAC susceptibility testing method for a wide range of antibiotic pathogen test pairs. The implications of this, for laboratories and prescribers, are discussed. [ABSTRACT FROM PUBLISHER]

Background: Salmonella spp are a major cause of food-borne outbreaks in Europe. We investigated a large multi-country outbreak of Salmonella enterica serotype Enteritidis in the EU and European Economic Area (EEA).Methods: A confirmed case was defined as a laboratory-confirmed infection with the outbreak strains of S Enteritidis based on whole-genome sequencing (WGS), occurring between May 1, 2015, and Oct 31, 2018. A probable case was defined as laboratory-confirmed infection with S Enteritidis with the multiple-locus variable-number tandem repeat analysis outbreak profile. Multi-country epidemiological, trace-back, trace-forward, and environmental investigations were done. We did a case-control study including confirmed and probable cases and controls randomly sampled from the population registry (frequency matched by age, sex, and postal code). Odds ratios (ORs) for exposure rates between cases and controls were calculated with unmatched univariable and multivariable logistic regression.Findings: 18 EU and EEA countries reported 838 confirmed and 371 probable cases. 509 (42%) cases were reported in 2016, after which the number of cases steadily increased. The case-control study results showed that cases more often ate in food establishments than did controls (OR 3·4 [95% CI 1·6-7·3]), but no specific food item was identified. Recipe-based food trace-back investigations among cases who ate in food establishments identified eggs from Poland as the vehicle of infection in October, 2016. Phylogenetic analysis identified two strains of S Enteritidis in human cases that were subsequently identified in salmonella-positive eggs and primary production premises in Poland, confirming the source of the outbreak. After control measures were implemented, the number of cases decreased, but increased again in March, 2017, and the increase continued into 2018.Interpretation: This outbreak highlights the public health value of multi-country sharing of epidemiological, trace-back, and microbiological data. The re-emergence of cases suggests that outbreak strains have continued to enter the food chain, although changes in strain population dynamics and fewer cases indicate that control measures had some effect. Routine use of WGS in salmonella surveillance and outbreak response promises to identify and stop outbreaks in the future.Funding: European Centre for Disease Prevention and Control; Directorate General for Health and Food Safety, European Commission; and National Public Health and Food Safety Institutes of the authors' countries (see Acknowledgments for full list). [ABSTRACT FROM AUTHOR]

Paratyphoid B fever (PTB) is caused by an invasive lineage (phylogroup 1, PG1) of Salmonella enterica serotype Paratyphi B (SPB). However, little was known about the global population structure, geographic distribution, and evolution of this pathogen. Here, we report a whole-genome analysis of 568 historical and contemporary SPB PG1 isolates, obtained globally, between 1898 and 2021. We show that this pathogen existed in the 13th century, subsequently diversifying into 11 lineages and 38 genotypes with strong phylogeographic patterns. Following its discovery in 1896, it circulated across Europe until the 1970s, after which it was mostly reimported into Europe from South America, the Middle East, South Asia, and North Africa. Antimicrobial resistance recently emerged in various genotypes of SPB PG1, mostly through mutations of the quinolone-resistance-determining regions of gyrA and gyrB. This study provides an unprecedented insight into SPB PG1 and essential genomic tools for identifying and tracking this pathogen, thereby facilitating the global genomic surveillance of PTB., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

From July through September 2000, patients in five European countries were infected with a multidrug-resistant strain of Salmonella Typhimurium DT204b. Epidemiologic investigations were facilitated by the transmission of electronic images (Tagged Image Files) of pulsed-field gel electrophoresis profiles. This investigation highlights the importance of standardized protocols for molecular typing in international outbreaks of foodborne disease.