Large-scale screening of a targeted Enterococcus faecalis mutant library identifies envelope fitness factors

Spread of antibiotic resistance among bacteria responsible for nosocomial and community-acquired infections urges for novel therapeutic or prophylactic targets and for innovative pathogen-specific antibacterial compounds. Major challenges are posed by opportunistic pathogens belonging to the low GC% gram-positive bacteria. Among those, Enterococcus faecalis is a leading cause of hospital-acquired infections associated with life-threatening issues and increased hospital costs. To better understand the molecular properties of enterococci that may be required for virulence, and that may explain the emergence of these bacteria in nosocomial infections, we performed the first large-scale functional analysis of E. faecalis V583, the first vancomycin-resistant isolate from a human bloodstream infection. E. faecalis V583 is within the high-risk clonal complex 2 group, which comprises mostly isolates derived from hospital infections worldwide. We conducted broad-range screenings of candidate genes likely involved in host adaptation (e.g., colonization and/or virulence). For this purpose, a library was constructed of targeted insertion mutations in 177 genes encoding putative surface or stress-response factors. Individual mutants were subsequently tested for their i) resistance to oxidative stress, ii) antibiotic resistance, iii) resistance to opsonophagocytosis, iv) adherence to the human colon carcinoma Caco-2 epithelial cells and v) virulence in a surrogate insect model. Our results identified a number of factors that are involved in the interaction between enterococci and their host environments. Their predicted functions highlight the importance of cell envelope glycopolymers in E. faecalis host adaptation. This study provides a valuable genetic database for understanding the steps leading E. faecalis to opportunistic virulence.

Haemophilus influenzae clinical isolates with plasmid pB1000 bearing blaROB-1: fitness cost and interspecies dissemination

Plasmid pB1000 is a mobilizable replicon bearing the bla(ROB-1) beta-lactamase gene that we have recently described in Haemophilus parasuis and Pasteurella multocida animal isolates. Here we report the presence of pB1000 and a derivative plasmid, pB1000', in four Haemophilus influenzae clinical isolates of human origin. Pulsed-field gel electrophoresis showed unrelated patterns in all strains, indicating that the existence of pB1000 in H. influenzae isolates is not the consequence of clonal dissemination. The replicon can be transferred both by transformation and by conjugation into H. influenzae, giving rise to recipients resistant to ampicillin and cefaclor (MICs, > or =64 microg/ml). Stability experiments showed that pB1000 is stable in H. influenzae without antimicrobial pressure for at least 60 generations. Competition experiments between isogenic H. influenzae strains with and without pB1000 revealed a competitive disadvantage of 9% per 10 generations for the transformant versus the recipient. The complete nucleotide sequences of nine pB1000 plasmids from human and animal isolates, as well as the epidemiological data, suggest that animal isolates belonging to the Pasteurellaceae act as an antimicrobial resistance reservoir for H. influenzae. Further, since P. multocida is the only member of this family that can colonize both humans and animals, we propose that P. multocida is the vehicle for the transport of pB1000 between animal- and human-adapted members of the Pasteurellaceae.

Socio-economic status, growth, physical activity and fitness: the Madeira growth study

Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.

Developmental and physical-fitness associations with gross motor coordination problems in peruvian children

he aims of this cross-sectional study were to examine the developmental characteristics (biological maturation and body size) associated with gross motor coordination problems in 5193 Peruvian children (2787 girls) aged 6–14 years from different geographical locations, and to investigate how the probability that children suffer with gross motor coordination problems varies with physical fitness. Children with gross motor coordination problems were more likely to have lower flexibility and explosive strength levels, having adjusted for age, sex, maturation and study site. Older children were more likely to suffer from gross motor coordination problems, as were those with greater body mass index. However, more mature children were less likely to have gross motor coordination problems, although children who live at sea level or at high altitude were more likely to suffer from gross motor coordination problems than children living in the jungle. Our results provide evidence that children and adolescents with lower physical fitness are more likely to have gross motor coordination difficulties. The identification of youths with gross motor coordination problems and providing them with effective intervention programs is an important priority in order to overcome such developmental problems, and help to improve their general health status.

Synonymous co-variation across the E1/E2 gene junction of hepatitis C virus defines virion fitness

Hepatitis C virus is a positive-sense single-stranded RNA virus. The gene junction partitioning the viral glycoproteins E1 and E2 displays concurrent sequence evolution with the 3′-end of E1 highly conserved and the 5′-end of E2 highly heterogeneous. This gene junction is also believed to contain structured RNA elements, with a growing body of evidence suggesting that such structures can act as an additional level of viral replication and transcriptional control. We have previously used ultradeep pyrosequencing to analyze an amplicon library spanning the E1/E2 gene junction from a treatment naïve patient where samples were collected over 10 years of chronic HCV infection. During this timeframe maintenance of an in-frame insertion, recombination and humoral immune targeting of discrete virus sub-populations was reported. In the current study, we present evidence of epistatic evolution across the E1/E2 gene junction and observe the development of co-varying networks of codons set against a background of a complex virome with periodic shifts in population dominance. Overtime, the number of codons actively mutating decreases for all virus groupings. We identify strong synonymous co-variation between codon sites in a group of sequences harbouring a 3 bp in-frame insertion and propose that synonymous mutation acts to stabilize the RNA structural backbone.

Physical exercise minimizes the toxic triad for cancer: Physical inactivity, low fitness, and obesity

The so-called toxic triad of factors linked to cancer, namely obesity, poor cardiorespiratory fitness and physical inactivity, increase the risk of cancer and, when cancer is present, worsen its prognosis. Thus, obesity and a sedentary lifestyle have been linked to an elevated cancer risk whereas regular physical exercise and good cardiorespiratory function (CRF) diminish this risk. Despite genetic risk factors, there is evidence to show that some lifestyle modifications are capable of reducing the incidence of cancer and its associated morbidity and mortality. Regular physical exercise targeted at maintaining body weight within healthy limits and improving CRF will reduce a person's cancer risk and, once diagnosed, will also improve its prognosis, reducing mortality and the risk of disease recurrence through similar effects. In this review, we describe how physical activity can be used as a pleiotropic, coadjuvant tool to minimize the toxic triad for cancer and update the mechanisms proposed to date for the effects observed.

Preparing fitness programmes

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Safety guidelines for group fitness to music

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The importance of physical fitness in the performance of adequate cardiopulmonary resuscitation

The aim of the present investigation was to evaluate the influence of the physical fitness of a cardiopulmonary resuscitation (CPR) provider on the performance of and physiologic response to CPR. To this end, comparisons were made of sedentary and physically active subjects in terms of CPR performance and physiologic variables. Two study groups were established: group P (n = 14), composed of sedentary, professional CPR rescuers (mean [± SD]; age, 34 ± 6 years; V̇O2max, 32.5 ± 5.5 mL/kg/min), and group Ex (n = 14), composed of physically active, nonexperienced subjects (age, 34 ± 6 years; V̇O2max, 44.5 ± 8.5 mL/kg/min). Each subject was required to perform an 18-min CPR session, which involved manual external cardiac compressions (ECCs) on an electronic teaching mannequin following accepted standard CPR guidelines. Subjects' gas exchange parameters and heart rates (HRs) were monitored throughout the trial. Variables indicating the adequacy of the ECCs (ECC depth and the percentage of incorrect compressions and hand placements) also were determined. Overall CPR performance was similar in both groups. The indicators of ECC adequacy fell within accepted limits (ie, an ECC depth between 38 and 51 mm). However, fatigue prevented four subjects from group P from completing the trial. In contrast, the physiologic responses to CPR differed between groups. The indicators of the intensity of effort during the trial, such as HR or percentage of maximum oxygen uptake (V̇O2max) were higher in group P subjects than group Ex subjects, respectively (HRs at the end of the trial, 139 ± 22 vs 115 ± 17 beats/min, p < 0.01; percentage of V̇O2max after 12 min of CPR, 46.7 ± 9.7% vs 37.2 ± 10.4%, p < 0,05). These results suggest that a certain level of physical fitness may be beneficial to CPR providers to ensure the adequacy of chest compressions performed during relatively long periods of cardiac arrest.

Socio-economic status, growth, physical activity and fitness: the Madeira growth study

Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.

Developmental and physical-fitness associations with gross motor coordination problems in peruvian children

he aims of this cross-sectional study were to examine the developmental characteristics (biological maturation and body size) associated with gross motor coordination problems in 5193 Peruvian children (2787 girls) aged 6–14 years from different geographical locations, and to investigate how the probability that children suffer with gross motor coordination problems varies with physical fitness. Children with gross motor coordination problems were more likely to have lower flexibility and explosive strength levels, having adjusted for age, sex, maturation and study site. Older children were more likely to suffer from gross motor coordination problems, as were those with greater body mass index. However, more mature children were less likely to have gross motor coordination problems, although children who live at sea level or at high altitude were more likely to suffer from gross motor coordination problems than children living in the jungle. Our results provide evidence that children and adolescents with lower physical fitness are more likely to have gross motor coordination difficulties. The identification of youths with gross motor coordination problems and providing them with effective intervention programs is an important priority in order to overcome such developmental problems, and help to improve their general health status.

Normative reference values for the 20-meter shuttlerun test in a population-based sample of schoolchildren in Bogota, Colombia: The FUPRECOL Study

Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio-metabolic risk.

Cardiorespiratory fitness and cardiometabolic risk factors in schoolchildren from Colombia: The FUPRECOL Study

The objectives of this study are to investigate the association between cardiorespiratory fitness and cardiovascular risk factors in schoolchildren and to evaluate the degree of association between overall and abdominal adiposity and cardiorespiratory fitness. A total of 1,875 children and adolescents attending public schools in Bogota, Colombia (56.2% girls; age range of 9–17.9 years). A cardiovascular risk score (Z-score) was calculated and participants were divided into tertiles according to low and high levels of overall (sum of the skinfold thicknesses) and abdominal adiposity. Schoolchildren with a high level of overall adiposity demonstrated significant differences in seven of the 10 variables analyzed (i.e. systolic and diastolic blood pressure, triglycerides, triglycerides/HDL-c ratio, total cholesterol, glucose and cardiovascular risk score). Schoolchildren with high levels of both overall and abdominal adiposity and low cardiorespiratory fitness had the least favorable cardiovascular risk factors score. These findings may be relevant to health promotion in Colombian youth.

Validity and reliability of the international fItness scale (IFIS) in a population-based sample of schoolchildren in Bogota, Colombia: The FUPRECOL study

The International FItness Scale (IFIS) is a self-reported measure of physical fitness that could easily. This scale has been validated in children, adolescents, and young adults; however, it is unknown whether the IFIS represents a valid and reliable estimate of physical fitness in Latino-American youth population. In the present study we aimed to examine the validity and reliability of the IFIS on a population-based sample of schoolchildren in Bogota, Colombia. Participants were 1,875 Colombian youth (56.2% girls) aged 9 to 17.9 years old. We measured adiposity markers (body fat, waist-to-height ratio, skinfold thicknesses and BMI), blood pressure, lipids profile, fasting glucose, and physical fitness level (self reported and measured). Also, a validated cardiometabolic risk index was used. An age- and sex-matched sample of 229 Schoolchildren originally not included in the study sample fulfilled IFIS twice for reliability purposes. Our data suggest that both measured and self-reported overall fitness were associated inversely with adiposity indicators and a cardiometabolic risk score. Overall, schoolchildren who self-reported “good” and “very good” fitness had better measured fitness than those who reported “very poor” and “poor” fitness (all p<0.001). Test–retest reliability of IFIS items was also good, with an average weighted Kappa of 0.811. Therefore, our findings suggest that self-reported fitness, as assessed by IFIS, is a valid, reliable, and health-related measure, and it can be a good alternative for future use in large studies with Latin-schoolchildren from Colombia.

Propiedades psicométricas de los instrumentos para la medición de la actividad física en adultos con discapacidad física relacionada con lesión de médula espinal: una revisión sistemática

Objetivo: Evaluar las propiedades psicométricas de los instrumentos para la medición de la actividad física en adultos de 18-65 años con discapacidad física por lesión de médula espinal. Materiales y métodos: Revisión sistemática. Las bases de datos de Medline, Scopus, Web of Science y 19 revistas especializadas fueron consultadas durante once días entre abril de 2015 y febrero de 2016 para identificar estudios originales de validación, sin límite de tiempo y que estuvieran publicados en español, francés y/o inglés. La calidad metodológica de los instrumentos de medición se evaluó usando las diferentes cajas de propiedades de la lista COSMIN. Resultados: Se identificaron 9229 referencias, de las cuales sólo 12 cumplieron los criterios de inclusión, dando como resultado 13 instrumentos de medición. Se evaluaron seis propiedades psicométricas. La propiedad más común fue la confiabilidad, además se observó que la calidad metodológica de los estudios incluidos no representa los resultados de las propiedades psicométricas de los instrumentos de medición. La calidad metodológica de los instrumentos para la evaluación de la actividad física en población con lesión medular espinal es “baja” para propiedades como consistencia interna, error de medición, sensibilidad, validez de criterio (con excepción del WISCI II que tiene buena validez) y excelente para validez de contenido y fiabilidad. Conclusión: Se ha encontrado que instrumentos empleados hasta el presente en la medición de la actividad física en población con discapacidad física relacionada con lesión de médula espinal han sido creados para otros tipos de discapacidad y otros instrumentos deben ser validados en futuros estudios.