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Importance: Colonization with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) often precedes infections and is therefore considered as a great threat for public health. Here, we studied the gut microbiome dynamics in eight index patients colonized with ESBL-PE after hospital discharge and the impact of exposure to this index patient on the gut microbiome dynamics of their household contacts. We showed that the microbiome composition from index patients is different from their household contacts upon hospital discharge and that, in some of the index patients, their microbiome composition over time shifted toward the composition of their household contacts. In contrast, household contacts showed a stable microbiome composition over time irrespective of low-level extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) gut colonization, suggesting that, in healthy microbiomes, colonization resistance is able to prevent ESBL-PE expansion., Competing Interests: The authors declare no conflict of interest.

Objectives: To assess the extent to which food items are a source of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli (ESBL-Ec) and ESBL-producing Klebsiella pneumoniae (ESBL-Kp) for humans in five European cities., Methods: We sampled 122 human polluted (hp)-environments (sewers and polluted rivers, as a proxy of human contamination) and 714 food items in Besançon (France), Geneva (Switzerland), Sevilla (Spain), Tübingen (Germany) and Utrecht (The Netherlands). A total of 254 ESBL-Ec and 39 ESBL-Kp isolates were cultured. All genomes were fully sequenced to compare their sequence types (ST) and core genomes, along with the distribution of bla ESBL genes and their genetic supports (i.e. chromosome or plasmid)., Results: Sequence data revealed that ESBL-Ec and ESBL-Kp isolates from hp-environments were genetically different from those contaminating food items. ESBL-Ec ST131 was widespread in the hp-environment (21.5% of the isolates) but absent from the food items tested. ESBL-Ec ST10 was in similar proportions in hp-environments and food items (15 and 10 isolates, respectively) but mostly carried reservoir-specific bla ESBL . bla CTX-M-1 and bla SHV-12 predominated in food-related E. coli isolates (32% and 34% of the isolates, respectively), whereas bla CTX-M-15 and bla CTX-M-27 predominated in isolates from hp-environments (52% and 15% of the isolates, respectively)., Conclusions: We found a very limited connection between ESBL-Ec and ESBL-Kp populations retrieved in food items and from hp-environments and bla ESBL . This suggests that human-to-human contamination, rather than the food chain, is possibly the most frequent route of ESBL-Ec and ESBL-Kp transmission in high-income countries., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: This study aimed to determine rates and risk factors of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) acquisition and transmission within households after hospital discharge of an ESBL-PE-positive index patient., Methods: Two-year prospective cohort study in five European cities. Patients colonized with ESBL-producing Escherichia coli (ESBL-Ec) or Klebsiella pneumoniae (ESBL-Kp), and their household contacts were followed up for 4 months after hospital discharge of the index case. At each follow up, participants provided a faecal sample and personal information. ESBL-PE whole-genome sequences were compared using pairwise single nucleotide polymorphism-based analysis., Results: We enrolled 71 index patients carrying ESBL-Ec (n = 45), ESBL-Kp (n = 20) or both (n = 6), and 102 household contacts. The incidence of any ESBL-PE acquisition among household members initially free of ESBL-PE was 1.9/100 participant-weeks at risk. Nineteen clonally related household transmissions occurred (case to contact: 13; contact to case: 6), with an overall rate of 1.18 transmissions/100 participant-weeks at risk. Most of the acquisition and transmission events occurred within the first 2 months after discharge. The rate of ESBL-Kp household transmission (1.16/100 participant-weeks) was higher than of ESBL-Ec (0.93/100 participant-weeks), whereas more acquisitions were noted for ESBL-Ec (1.06/100 participant-weeks) compared with ESBL-Kp (0.65/100 participant-weeks). Providing assistance for urinary and faecal excretion to the index case by household members increased the risk of ESBL-PE transmission (adjusted prevalence ratio 4.3; 95% CI 1.3-14.1)., Conclusions: ESBL-PE cases discharged from the hospital are an important source of ESBL-PE transmission within households. Most acquisition and transmission events occurred during the first 2 months after hospital discharge and were causally related to care activities at home, highlighting the importance of hygiene measures in community settings., Clinical Study Registration: German Clinical Trials Register, DRKS-ID: DRKS00013250., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: The epidemiology of ESBL-producing Enterobacteriaceae (ESBL-PE) has been extensively studied in hospitals, but data on community transmission are scarce. We investigated ESBL-PE cocarriage and acquisition in households using a systematic literature review., Methods: We conducted a systematic literature search to retrieve cross-sectional or cohort studies published between 1990 and 2018 evaluating cocarriage proportions and/or acquisition rates of ESBL-PE among household members, without language restriction. We excluded studies focusing on animal-to-human transmission or conducted in nonhousehold settings. The main outcomes were ESBL-PE cocarriage proportions and acquisition rates, stratified according to phenotypic or genotypic assessment of strain relatedness. Cocarriage proportions of clonally related ESBL-PE were transformed using the double-arcsine method and were pooled using a random-effects model. Potential biases were assessed manually., Results: We included 13 studies. Among 863 household members of ESBL-PE positive index cases, prevalence of ESBL-PE cocarriage ranged from 8% to 37%. Overall, 12% (95% confidence interval [CI], 8%-16%) of subjects had a clonally related strain. Those proportions were higher for Klebsiella pneumoniae (20%-25%) than for Escherichia coli (10%-20%). Acquisition rates of clonally related ESBL-PE among 180 initially ESBL-PE-free household members of a previously identified carrier ranged between 1.56 and 2.03 events per 1,000 person weeks of follow-up. We identified multiple sources of bias and high heterogeneity (I2, 70%) between studies., Conclusions: ESBL-PE household cocarriage is frequent, suggesting intrafamilial acquisition. Further research is needed to evaluate the risk and control of ESBL-PE household transmission.

We present here the results of the Analysis of HLA Population Data (AHPD) project of the 16th International HLA and Immunogenetics Workshop (16IHIW) held in Liverpool in May-June 2012. Thanks to the collaboration of 25 laboratories from 18 different countries, HLA genotypic data for 59 new population samples (either well-defined populations or donor registry samples) were gathered and 55 were analysed statistically following HLA-NET recommendations. The new data included, among others, large sets of well-defined populations from north-east Europe and West Asia, as well as many donor registry data from European countries. The Gene[rate] computer tools were combined to create a Gene[rate] computer pipeline to automatically (i) estimate allele frequencies by an expectation-maximization algorithm accommodating ambiguities, (ii) estimate heterozygosity, (iii) test for Hardy-Weinberg equilibrium (HWE), (iv) test for selective neutrality, (v) generate frequency graphs and summary statistics for each sample at each locus and (vi) plot multidimensional scaling (MDS) analyses comparing the new samples with previous IHIW data. Intrapopulation analyses show that HWE is rarely rejected, while neutrality tests often indicate a significant excess of heterozygotes compared with neutral expectations. The comparison of the 16IHIW AHPD data with data collected during previous workshops (12th-15th) shows that geography is an excellent predictor of HLA genetic differentiations for HLA-A, -B and -DRB1 loci but not for HLA-DQ, whose patterns are probably more influenced by natural selection. In Europe, HLA genetic variation clearly follows a north to south-east axis despite a low level of differentiation between European, North African and West Asian populations. Pacific populations are genetically close to Austronesian-speaking South-East Asian and Taiwanese populations, in agreement with current theories on the peopling of Oceania. Thanks to this project, HLA genetic variation is more clearly defined worldwide and better interpreted in relation to human peopling history and HLA molecular evolution., (© 2012 Blackwell Publishing Ltd.)

HLA-NET (a European COST Action) aims at networking researchers working in bone marrow transplantation, epidemiology and population genetics to improve the molecular characterization of the HLA genetic diversity of human populations, with an expected strong impact on both public health and fundamental research. Such improvements involve finding consensual strategies to characterize human populations and samples and report HLA molecular typings and ambiguities; proposing user-friendly access to databases and computer tools and defining minimal requirements related to ethical aspects. The overall outcome is the provision of population genetic characterizations and comparisons in a standard way by all interested laboratories. This article reports the recommendations of four working groups (WG1-4) of the HLA-NET network at the mid-term of its activities. WG1 (Population definitions and sampling strategies for population genetics' analyses) recommends avoiding outdated racial classifications and population names (e.g. 'Caucasian') and using instead geographic and/or cultural (e.g. linguistic) criteria to describe human populations (e.g. 'pan-European'). A standard 'HLA-NET POPULATION DATA QUESTIONNAIRE' has been finalized and is available for the whole HLA community. WG2 (HLA typing standards for population genetics analyses) recommends retaining maximal information when reporting HLA typing results. Rather than using the National Marrow Donor Program coding system, all ambiguities should be provided by listing all allele pairs required to explain each genotype, according to the formats proposed in 'HLA-NET GUIDELINES FOR REPORTING HLA TYPINGS'. The group also suggests taking into account a preliminary list of alleles defined by polymorphisms outside the peptide-binding sites that may affect population genetic statistics because of significant frequencies. WG3 (Bioinformatic strategies for HLA population data storage and analysis) recommends the use of programs capable of dealing with ambiguous data, such as the 'gene[rate]' computer tools to estimate frequencies, test for Hardy-Weinberg equilibrium and selective neutrality on data containing any number and kind of ambiguities. WG4 (Ethical issues) proposes to adopt thorough general principles for any HLA population study to ensure that it conforms to (inter)national legislation or recommendations/guidelines. All HLA-NET guidelines and tools are available through its website http://hla-net.eu., (© 2012 Blackwell Publishing Ltd.)

The development of molecular typing techniques applied to the study of population genetic diversity originates data with increasing precision but at the cost of some ambiguities. As distinct techniques may produce distinct kinds of ambiguities, a crucial issue is to assess the differences between frequency distributions estimated from data produced by alternative techniques for the same sample. To that aim, we developed a resampling scheme that allows evaluating, by statistical means, the significance of the difference between two frequency distributions. The same approach is then shown to be applicable to test selective neutrality when only sample frequencies are known. The use of these original methods is presented here through an application to the genetic study of a Munda human population sample, where three different HLA loci were typed using two different molecular methods (reverse PCR-SSO typing on microbeads arrays based on Luminex technology and PCR-SSP typing), as described in details in the companion article by Riccio et al. [The Austroasiatic Munda population from India and its enigmatic origin: An HLA diversity study. Hum. Biol. 38:405-435 (2011)]. The differences between the frequency estimates of the two typing techniques were found to be smaller than those resulting from sampling. Overall, we show that using a resampling scheme in validating frequency estimates is effective when alternative frequency estimates are available. Moreover, resampling appears to be the unique way to test selective neutrality when only frequency data are available to describe the genetic structure of populations.

The Austroasiatic linguistic family disputes its origin between two geographically distant regions of Asia, India, and Southeast Asia, respectively. As genetic studies based on classical and gender-specific genetic markers provided contradictory results to this debate thus far, we investigated the HLA diversity (HLA-A, -B, and -DRB1 loci) of an Austroasiatic Munda population from Northeast India and its relationships with other populations from India and Southeast Asia. Because molecular methods currently used to test HLA markers often provide ambiguous results due to the high complexity of this polymorphism, we applied two different techniques (reverse PCR-SSO typing on microbeads arrays based on Luminex technology, and PCR-SSP typing) to type the samples. After validating the resulting frequency distributions through the original statistical method described in our companion article ( Nunes et al. 2011 ), we compared the HLA genetic profile of the sampled Munda to those of other Asiatic populations, among which Dravidian and Indo-European-speakers from India and populations from East and Southeast Asia speaking languages belonging to different linguistic families. We showed that the Munda from Northeast India exhibit a peculiar genetic profile with a reduced level of HLA diversity compared to surrounding Indian populations. They also exhibit less diversity than Southeast Asian populations except at locus DRB1. Several analyses using genetic distances indicate that the Munda are much more closely related to populations from the Indian subcontinent than to Southeast Asian populations speaking languages of the same Austroasiatic linguistic family. On the other hand, they do not share a closer relationship with Dravidians compared with Indo-Europeans, thus arguing against the idea that the Munda share a common and ancient Indian origin with Dravidians. Our results do not favor either a scenario where the Munda would be representative of an ancestral Austroasiatic population giving rise to an eastward Austroasiatic expansion to Southeast Asia. Rather, their peculiar genetic profile is better explained by a decrease in genetic diversity through genetic drift from an ancestral population having a genetic profile similar to present-day Austroasiatic populations from Southeast Asia (thus suggesting a possible southeastern origin), followed by intensive gene flow with neighboring Indian populations. This conclusion is in agreement with archaeological and linguistic information. The history of the Austroasiatic family represents a fascinating example where complex interactions among culturally distinct human populations occurred in the past.

This study reports extensive genomic data for both human leukocyte antigen (HLA) class I and II loci in Norwegian Sami, a native population living in the northwest of Europe. The Sami have a distinct culture and their own languages, which belong to the Uralic linguistic family. Norwegian Sami (n = 200) were typed at the DNA level for the HLA-A, -C, -B, -DRB1 and -DQB1 loci, and compared with a non-Sami Norwegian population (n = 576). The two populations exhibited some common genetic features but also differed significantly at all HLA loci. The most significantly deviating allele frequencies were an increase of HLA-A*03, -B*27, -DRB1*08 and -DQB1*04 and a decrease of HLA-A*01, C*01, -DRB1*04 and -DQB1*02 among Sami compared with non-Sami Norwegians. The Sami showed no deviation from Hardy-Weinberg equilibrium. The hypothesis of selective neutrality was rejected at all loci except for the A- and C- loci for the Sami. HLA haplotype frequencies also differed between the two populations. The most common extended HLA haplotypes were A*02-B*27-C*01-DR*08-DQB1*04 in the Sami and A*01-B*08-C*07-DR*03-DQB1*02 in the other Norwegians. Genetic distance analyses indicated that the Norwegian Sami were highly differentiated from other Europeans and were most closely related to Finns whose language also belongs to the Uralic linguistic family. In conclusion, the Norwegian Sami and the non-Sami Norwegians were significantly different at all HLA loci. Our results can be explained by the fact that the two populations have different origins and that the Sami population has remained smaller and more isolated than its neighbors.

Purpose: Previous studies have suggested that muscle coactivation could be reduced by a recurrent activity (training, daily activities). If this was correct, skilled athletes should show a specific muscle activation pattern with a low level of coactivation of muscles which are typically involved in their discipline. In particular, the aim of this study was to verify the hypothesis that the amount of antagonist activation of biceps brachii (BB) and triceps brachii (TB) is different between tennis players and non-players individuals during maximal isokinetic contractions., Methods: Ten young healthy men and eight male tennis players participated in the study. The surface electromyographic signals (sEMG) were recorded from the BB and TB muscles during three maximal voluntary isometric contractions (MVC) of elbow flexors and extensors and a set of three maximal elbow flexions and extensions at 15 degrees , 30 degrees , 60 degrees , 120 degrees , 180 degrees and 240 degrees /s. Normalized root mean square (RMS) of sEMG was calculated as an index of sEMG amplitude., Results: Antagonist activation (%RMSmax) of TB was significantly lower in tennis players (from 14.0+/-7.9% at MVC to 16.3+/-8.9% at 240 degrees /s) with respect to non-players (from 27.7+/-19.7% at MVC to 38.7+/-17.6% at 240 degrees /s) at all angular velocities. Contrary to non-players, tennis players did not show any difference in antagonist activation between BB and TB muscles., Conclusions: Tennis players, with a constant practice in controlling forces around the elbow joint, learn how to reduce coactivation of muscles involved in the control of this joint. This has been shown by the lower antagonist muscular activity of triceps brachii muscle during isokinetic elbow flexion found in tennis players with respect to non-players.

Our aim was to analyze the incidence of mutations in BRCA1 and BRCA2 genes in 54 families with breast/ovarian cancer. Families were selected from three Institutions following the standard criteria for hereditary breast/ovarian cancer. PCR amplification of all exons was performed, followed by SSCP, heteroduplex, PTT and sequencing analysis. We identified eight truncation mutations, three in the BRCA1 gene and five in the BRCA2 gene. Three of these mutations have not been reported previously by other groups: 308insA in one family, 3936 C>T in two families, for BRCA1, and 4970insTG in one family for BRCA2. In addition two families having Ashkenazi Jewish ancestors present the well known mutations 185delAG and 6174delT. Interestingly, 5 out of 11 families have mutations recurrent in Spanish families. Among the 54 families selected, seven have breast and ovary cancer cases, and only two presented a mutation in BRCA1 or BRCA2 genes. Other cancers as prostate and stomach are frequent among relatives carrying the mutation. Five cases of very early onset (<31 years old) breast cancer were detected. The frequencies of BRCA1 (0.074) and BRCA2 (0.13) mutations in our families is low but similar to the incidence found in other populations, like in Spain. Since is widely known that risk factors that modulate the development of breast cancer such as lifestyle risk factors, geographic location, country of origin and socioeconomic status, besides a familial history of breast cancer our findings suggest that the history of colonization and immigrations is very relevant when studying hereditary factors associated to breast cancer.