RESUMO
Fruiting efficiency (FE, grains per g of spike dry weight at anthesis) was proposed as a promising spike trait to improve wheat yield potential, based on its functional relationship with grain number determination and the evidence of trait variability in elite germplasm. During the last few years, we have witnessed great advances in the understanding of the physiological and genetic basis of this trait. The present review summarizes the recent heritability estimations and the genetic gains obtained when fruiting efficiency was measured at maturity (FEm, grains per g of chaff) and used as selection criterion. In addition, we propose spike ideotypes for contrasting fruiting efficiencies based on the fertile floret efficiency (FFE, fertile florets per g of spike dry weight at anthesis) and grain set (grains per fertile floret), together with other spike fertility-related traits. We also review novel genes and quantitative trait loci available for using marker-assisted selection for fruiting efficiency and other spike fertility traits. The possible trade-off between FE and grain weight and the genes reported to alter this relation are also considered. Finally, we discuss the benefits and future steps towards the use of fruiting efficiency as a selection criterion in breeding programs.
Assuntos
Melhoramento Vegetal , Triticum , Grão Comestível , Fenótipo , Locos de Características Quantitativas/genética , Triticum/genéticaRESUMO
A Shiga-toxin-producing Escherichia coli (STEC) strain belonging to serotype O104:H4, phylogenetic group B1 and sequence type ST678, with virulence features common to the enteroaggregative E. coli (EAEC) pathotype, was reported as the cause of the recent 2011 outbreak in Germany. The outbreak strain was determined to carry several virulence factors of extraintestinal pathogenic E. coli (ExPEC) and to be resistant to a wide range of antibiotics. There are only a few reports of serotype O104:H4, which is very rare in humans and has never been detected in animals or food. Several research groups obtained the complete genome sequence of isolates of the German outbreak strain as well as the genome sequences of EAEC of serotype O104:H4 strains from Africa. Those findings suggested that horizontal genetic transfer allowed the emergence of the highly virulent Shiga-toxin-producing enteroaggregative E. coli (STEAEC) O104:H4 strain responsible for the outbreak in Germany. Epidemiologic investigations supported a linkage between the outbreaks in Germany and France and traced their origin to fenugreek seeds imported from Africa. However, there has been no isolation of the causative strain O104:H4 from any of the samples of fenugreek seeds analyzed. Following the German outbreak, we conducted a large sampling to analyze the presence of STEC, EAEC, and other types of diarrheagenic E. coli strains in Spanish vegetables. During June and July 2011, 200 vegetable samples from different origins were analyzed. All were negative for the virulent serotype O104:H4 and only one lettuce sample (0.6%) was positive for a STEC strain of serotype O146:H21 (stx1, stx2), considered of low virulence. Despite the single positive case, the hygienic and sanitary quality of Spanish vegetables proved to be quite good. In 195 of the 200 samples (98%), <10 colony-forming units (cfu) of E. coli per gram were detected, and the microbiological levels of all samples were satisfactory (<100 cfu/g). The samples were also negative for other pathotypes of diarrheagenic E. coli (EAEC, ETEC, tEPEC, and EIEC). Consistent with data from other countries, STEC belonging to serotype O157:H7 and other serotypes have been isolated from beef, milk, cheese, and domestic (cattle, sheep, goats) and wild (deer, boar, fox) animals in Spain. Nevertheless, STEC outbreaks in Spain are rare.
Assuntos
Surtos de Doenças , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/análise , Microbiologia de Alimentos , Toxina Shiga/análise , Escherichia coli Shiga Toxigênica/genética , África , Animais , Animais Selvagens , Técnicas de Tipagem Bacteriana , Bovinos , Queijo/microbiologia , Contagem de Colônia Microbiana , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/transmissão , Proteínas de Escherichia coli/isolamento & purificação , França , Alemanha/epidemiologia , Cabras , Humanos , Incidência , Carne/microbiologia , Filogenia , Ovinos , Toxina Shiga/isolamento & purificação , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/isolamento & purificação , Escherichia coli Shiga Toxigênica/patogenicidade , Espanha/epidemiologia , Suínos , VirulênciaRESUMO
BACKGROUND: This research focuses on problems relating to creativity and problem-solving capacity faced by a specific group of professionals, as they relate to worker burnout, which is prevalent in a large number of work environments. OBJECTIVES: Our hypothesis was that creative people who follow method and order are less likely to suffer from burnout. Our objective was to demonstrate that health professionals working in surgery who are creative, methodical, and orderly have lower levels of burnout compared to others. DESIGN: A correlational, analytical, and cross-sectional study with 70 health professionals working in surgery. METHODS: A random sample of health professionals who worked in surgery at the Hospital Universitario de La Princesa in Madrid, Spain from 2011 to 2014 were studied. The variables considered in the study were: gender, age, profession, creativity score, method and order score, and burnout score. Measurement tools were CREA: creative intelligence (Corbalán & Martinez, 2003), MO2: method and order (Seisdedos, 1994), and the Maslach Burnout Inventory (MBI), a test of emotional exhaustion, depersonalization, and personal accomplishment (Maslach, 1981), all of which were validated for the Spanish population. RESULTS: Our data indicate that a worker's age influences his/her capacity to work with method and order, and that workers with emotional exhaustion (a basic feature of burnout) have lower scores in method and order. Greater emotional exhaustion and greater depersonalization were related to lower personal accomplishment and greater burnout. CONCLUSION: people who work with method and order are less likely to suffer from burnout. We did not find a direct relationship between creativity and method and order or between creativity and burnout.
Assuntos
Esgotamento Profissional/psicologia , Criatividade , Pessoal de Saúde/organização & administração , Pessoal de Saúde/psicologia , Satisfação no Emprego , Resolução de Problemas , Estresse Psicológico , Adulto , Fatores Etários , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espanha , Inquéritos e QuestionáriosRESUMO
A collection of 69 eae-positive strains expressing 29 different intimin types and eight tir alleles was characterized with respect to their adherence patterns to HeLa cells, ability to promote actin accumulation in vitro, the presence of bfpA alleles in positive strains, and bundle-forming pilus (BFP) expression. All of the nine typical enteropathogenic Escherichia coli (tEPEC) studied harbored the enteropathogenic E. coli adherence factor (EAF) plasmid, as shown by PCR and/or EAF probe results. In addition, they were positive for bfpA, as shown by PCR, and BFP expression, as confirmed by immunofluorescence (IFL) and/or immunoblotting (IBL) assays. Localized adherence (LA) was exclusively displayed by those nine tEPEC, while localized-adherence-like (LAL) was the most frequent pattern among atypical EPEC (aEPEC) and Shiga-toxinproducing E. coli (STEC). All LA and LAL strains were able to cause attaching and effacing (AE) lesions, as established by means of the FAS test. There was a significant association between the presence of tir allele alpha1 and bfpA-positive strains, and consequently, with the LA pattern. However, intimin type or bfpA was not associated with the adherence pattern displayed in HeLa cells. Among the eight bfpA alleles detected, a new type (beta10; accession number FN391178) was identified in a strain of serotype O157:H45, and a truncated variant (beta3.2-t; accession number FN 391181) in four strains belonging to different pathotypes.
Assuntos
Actinas/metabolismo , Adesinas Bacterianas/genética , Aderência Bacteriana , Escherichia coli Enteropatogênica/patogenicidade , Proteínas de Escherichia coli/genética , Receptores de Superfície Celular/genética , Escherichia coli Shiga Toxigênica/patogenicidade , Fatores de Virulência/genética , Alelos , DNA Bacteriano/genética , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Proteínas de Fímbrias/genética , Fímbrias Bacterianas/fisiologia , Genótipo , Células HeLa , Humanos , Microscopia de Fluorescência , Plasmídeos , Reação em Cadeia da Polimerase , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
In Spain, as in many other countries, verotoxin-producing Escherichia coli (VTEC) strains have been frequently isolated from cattle, sheep, and foods. VTEC strains have caused seven outbreaks in Spain (six caused by E. coli O157:H7 and one by E. coli O111:H- [nonmotile]) in recent years. An analysis of the serotypes indicated serological diversity. Among the strains isolated from humans, serotypes O26:H11, O111:H-, and O157:H7 were found to be more prevalent. The most frequently detected serotypes in cattle were O20:H19, O22:H8, O26:H11, O77:H41, O105:H18, O113:H21, O157:H7, O171:H2, and OUT (O untypeable):H19. Different VTEC serotypes (e.g., O5:H-, O6:H10, O91:H-, O117:H-, O128:H-, O128:H2, O146:H8, O146:H21, O156:H-, and OUT:H21) were found more frequently in sheep. These observations suggest a host serotype specificity for some VTEC. Numerous bovine and ovine VTEC serotypes detected in Spain were associated with human illnesses, confirming that ruminants are important reservoirs of pathogenic VTEC. VTEC can produce one or two toxins (VT1 and VT2) that cause human illnesses. These toxins are different proteins encoded by different genes. Another virulence factor expressed by VTEC is the protein intimin that is responsible for intimate attachment of VTEC and effacing lesions in the intestinal mucosa. This virulence factor is encoded by the chromosomal gene eae. The eae gene was found at a much less frequency in bovine (17%) and ovine (5%) than in human (45%) non-O157 VTEC strains. This may support the evidence that the eae gene contributes significantly to the virulence of human VTEC strains and that many animal non-O157 VTEC strains are less pathogenic to humans.
Assuntos
Infecções por Escherichia coli/epidemiologia , Escherichia coli/isolamento & purificação , Doenças Transmitidas por Alimentos/epidemiologia , Genes Bacterianos , Carne/microbiologia , Toxinas Shiga/biossíntese , Virulência/genética , Animais , Bovinos , Surtos de Doenças , Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Cabras , Humanos , Prevalência , Ovinos , Espanha/epidemiologiaRESUMO
Stool specimens of patients with diarrhea or other gastrointestinal alterations who were admitted to Xeral-Calde Hospital (Lugo, Spain) were analyzed for the prevalence of typical and atypical enteropathogenic Escherichia coli (EPEC). Atypical EPEC strains (eae+ bfp-) were detected in 105 (5.2%) of 2015 patients, whereas typical EPEC strains (eae+ bfp+) were identified in only five (0.2%) patients. Atypical EPEC strains were (after Salmonella) the second most frequently recovered enteropathogenic bacteria. In this study, 110 EPEC strains were characterized. The strains belonged to 43 O serogroups and 69 O:H serotypes, including 44 new serotypes not previously reported among human EPEC. However, 29% were of one of three serogroups (O26, O51, and O145) and 33% belonged to eight serotypes (O10:H-, O26:H11, O26:H-, O51:H49, O123:H19, O128:H2, O145:H28, and O145:H-). Only 14 (13%) could be assigned to classical EPEC serotypes. Fifteen intimin types, namely, alpha1 (6 strains), alpha2 (4 strains), beta1 (34 strains), xiR/b2 (6 strains), gamma1 (13 strains), gamma2/q (16 strains), delta/k (5 strains), epsilon1 (9 strains), nuR/e2 (5 strains), zeta (6 strains), iota1 (1 strain), muR/iota2 (1 strain), nuB (1 strain), xiB (1 strain), and o (2 strains), were detected among the 110 EPEC strains, but none of the strains was positive for intimin types mu1, mu2, lambda, or muB. In addition, in atypical EPEC strains of serotypes O10:H-, O84:H-, and O129:H-, two new intimin genes (eae-nuB and eae-o) were identified. These genes showed less than 95% nucleotide sequence identity with existing intimin types. Phylogenetic analysis revealed six groups of closely related intimin genes: (i) alpha1, alpha2, zeta, nuB, and o; (ii) iota1 and muR/iota2; (iii) beta1, xiR/beta2B, delta/beta2O, and kappa; (iv) epsilon1, xiB, eta1,eta2, and nuR/epsilon2; (v) gamma1, muB, gamma2, and theta; and (vi) lambda. These results indicate that atypical EPEC strains belonging to large number of serotypes and with different intimin types might be frequently isolated from human clinical stool samples in Spain.
Assuntos
Adesinas Bacterianas/genética , Proteínas de Escherichia coli/genética , Escherichia coli/classificação , Escherichia coli/genética , Adesinas Bacterianas/metabolismo , Animais , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Fezes/microbiologia , Humanos , Filogenia , Sorotipagem , VirulênciaRESUMO
Our primary goal was to assess health related quality of life (HRQOL) at transplantation and 1 yr after transplantation in pediatric liver transplant patients aged less than 5 years. We conducted a prospective longitudinal study of HRQOL in pediatric liver transplant recipients, aged less than 5 years to define the impact of liver transplantation on HRQOL and identify factors that predict HRQOL after transplantation. The infant toddler health status questionnaire (ITHQ) was completed at the time of listing for liver transplantation and at 6 and 12 months after liver transplantation. The primary outcome measures were the subscale scores that comprise ITHQ. The mean age (+/-s.e.m.) of the enrolled patients (n = 45) at transplantation was 1.4 (+/-1.2) yr. Thirty-eight (84%) of the enrolled patients completed the study. The highest mean baseline scores of 78.6 (+/-3.3) were for global mental health (GlobalMH). ITHQ subscale scores increased steadily after transplantation. The greatest increase was in the first 6 months after transplant. At 1 yr after transplantation, there were significant increases in all of the ITHQ subscale scores except for GlobalMH. ITHQ subscales were similar for patients who received LDLT compared with those who received cadaver donor liver transplantation (CDLT) at baseline and a year after transplant. Time elapsed as transplantation was a significant predictor of functional health in all of the models generated. Scores for general health (GH), global health (GGH), parental time-impact (PT) and parental time-emotion (PE) were higher for male children. Family cohesion (FC) improved with time elapsed since transplant and increased number of inpatient days. HRQOL improves after transplantation in all of our patients irrespective of the donor type. Functional health scores were higher in patients with normal serum bilirubin at 1 yr post-transplant. Assessment of HRQOL should be an integral part of care for liver transplant patients and their caregivers.
Assuntos
Nível de Saúde , Transplante de Fígado , Qualidade de Vida , Bilirrubina/sangue , Cadáver , Emoções , Feminino , Humanos , Lactente , Comportamento do Lactente , Doadores Vivos , Estudos Longitudinais , Masculino , Pais/psicologia , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: To compare the direct health care cost of living donor liver transplantation (LDLT) with that of cadaver donor liver transplantation (CDLT) in children and identify predictors of cost. STUDY DESIGN: All 16 children who underwent LDLT from January 1997 through January 2002 at Cincinnati Children's Hospital Medical Center comprised the study population. They were matched for age, diagnosis, and nutritional status with 31 children who received CDLT during the same era. A historic cohort analysis was performed. RESULTS: There was no difference in the 1-year mortality rates between both groups. Costs associated with graft retrieval contributed 15.3% and 31% of the initial transplant cost for LDLT and CDLT, respectively. Mean cost of care in the first year was 60.3% higher for LDLT than CDLT (P=.01). Multivariate analysis identified biliary complications and insurance status as predictors of cost for initial transplantation (R(2)=0.57), whereas biliary complications and pediatric end stage liver disease scores were identified as predictors of cost of care in the first year after transplantation (R(2)=0.77). CONCLUSIONS: The comprehensive cost of LDLT in the first year after transplantation is higher than cadaveric transplantation. This must be balanced against the time spent and care needs of patients on the waiting list.
Assuntos
Custos Diretos de Serviços , Transplante de Fígado/economia , Doadores Vivos , Cadáver , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Lactente , Transplante de Fígado/mortalidade , Masculino , Análise Multivariada , Ohio/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Taxa de Sobrevida , Obtenção de Tecidos e Órgãos/métodos , Resultado do TratamentoRESUMO
The goals of the present study were (1) to measure health-related quality of life (HRQOL) in pediatric liver transplantation (LT), (2) to identify demographic and clinical factors that correlate with HRQOL, and (3) to compare two instruments that have been used to measure HRQOL in children and adolescents. We conducted a single-center cross-sectional study of 77 pediatric LT recipients ages 5 to 18 years, all of whom had had LT at least 6 months previously. We used the Child Health Questionnaire Parent Form 50 (CHQPF50) and the PedsQL4.0 to determine measured dimensions of physical and psychosocial health from the parents' perspective. Individual scale scores range from 0 to 100, with higher scores reflecting better health. Data on demographics, clinical status at transplantation, posttransplantation clinical course, and graft function were collected to identify predictors of posttransplantation HRQOL. Fifty-three percent of the liver transplant recipients had biliary atresia, 78% were white, and 61% were female. The mean age at LT was 3.8 +/- 3.6 years, and the range of time since LT was 1 to 15 years. HRQOL in pediatric liver transplant recipients was lower than that reported for healthy children but similar to that for children with other chronic illness. Age at transplantation, the time elapsed since transplantation, hospitalizations within the previous year, maternal education, and race were significant predictors of physical health. Age at transplantation and maternal education predicted psychosocial function. HRQOL was decreased in a population of pediatric liver transplant recipients compared with the general population and similar to that for children with chronic illness. Prospective longitudinal studies will permit us to define predictors of HRQOL at different periods of time after transplantation. The information gained from this study will help us to better define expectations and the clinical course after liver transplantation to patients and their families.
Assuntos
Transplante de Fígado , Adolescente , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Análise Multivariada , Qualidade de Vida , Inquéritos e QuestionáriosRESUMO
As survival rates following liver transplantation have increased, health care providers must assess the impact of transplantation on dimensions other than traditional medical measures. Hearing impairment may adversely impact social, emotional, cognitive, academic, and speech and language development. We hypothesized that children who undergo liver transplantation are at risk for hearing impairment due to exposure to ototoxic drugs. We conducted a review of 74 children who had undergone liver transplantation between December 1996 and September 2000 at Cincinnati Children's Hospital Medical Center. Hearing was assessed at discharge by an audiologist using age and developmentally appropriate techniques. The principal outcome measure was sensorineural hearing impairment. Independent variables were age at transplantation, United Network for Organ Sharing (UNOS) status at transplantation, primary diagnosis, post-transplant length of hospital stay, days of treatment with aminoglycosides, and days of treatment with loop diuretics. Eleven of 74 children (15%) had sensorineural hearing loss, of whom four had severe to profound hearing loss. Multivariate analyses showed that the adjusted relative risk for hearing loss in patients with hepatoblastoma was 66 and that there was a 5% increase risk for hearing loss for each additional day of hospitalization. Age at transplantation, UNOS status, and days of treatment with loop diuretics or aminoglycosides did not achieve significance in the model. Sensorineural hearing impairment occurs in a subset of pediatric patients following liver transplantation. Patients with hepatoblastoma or those who experience prolonged hospitalization after transplantation are at increased risk. Our observations are of particular importance for pediatric liver transplant recipients since the median age at transplantation is 12-18 months, a critical period for language acquisition.
Assuntos
Perda Auditiva Neurossensorial/etiologia , Transplante de Fígado/efeitos adversos , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Tempo de Internação , Neoplasias Hepáticas/cirurgia , Masculino , Análise Multivariada , Estudos RetrospectivosRESUMO
A collection of 69 eae-positive strains expressing 29 different intimin types and eight tir alleles was characterizedwith respect to their adherence patterns to HeLa cells, ability to promote actin accumulation in vitro, the presence of bfpA alleles in positive strains, and bundle-forming pilus (BFP) expression. All of the nine typical enteropathogenic Escherichia coli (tEPEC) studied harbored the enteropathogenic E. coli adherence factor (EAF) plasmid, as shown by PCR and/or EAF probe results. In addition, they were positive for bfpA, as shown by PCR, and BFP expression, as confirmed by immunofluorescence(IFL) and/or immunoblotting (IBL) assays. Localized adherence (LA) was exclusively displayed by those ninetEPEC, while localized-adherence-like (LAL) was the most frequent pattern among atypical EPEC (aEPEC) and Shiga-toxinproducing E. coli (STEC). All LA and LAL strains were able to cause attaching and effacing (AE) lesions, as established by means of the FAS test. There was a significant association between the presence of tir allele á1 and bfpA-positive strains, and consequently, with the LA pattern. However, intimin type or bfpA was not associated with the adherence pattern displayed in HeLa cells. Among the eight bfpA alleles detected, a new type (â10; accession number FN391178) was identified in a strain of serotype O157:H45, and a truncated variant (â3.2-t; accession number FN 391181) in four strains belonging to differentpathotypes.
Assuntos
Humanos , Escherichia coli , Escherichia coli Enteropatogênica , Toxinas Shiga , Células HeLa/citologiaRESUMO
A Shiga-toxin-producing Escherichia coli (STEC) strain belonging to serotype O104:H4, phylogenetic group B1 and sequence type ST678, with virulence features common to the enteroaggregative E. coli (EAEC) pathotype, was reported as the cause of the recent 2011 outbreak in Germany. The outbreak strain was determined to carry several virulence factors of extraintestinal pathogenic E. coli (ExPEC) and to be resistant to a wide range of antibiotics. There are only a few reports of serotype O104:H4, which is very rare in humans and has never been detected in animals or food. Several research groups obtained the complete genome sequence of isolates of the German outbreak strain as well as the genome sequences of EAEC of serotype O104:H4 strains from Africa. Those findings suggested that horizontal genetic transfer allowed the emergence of the highly virulent Shiga-toxin-producing enteroaggregative E. coli (STEAEC) O104:H4 strain responsible for the outbreak in Germany. Epidemiologic investigations supported a linkage between the outbreaks in Germany and France and traced their origin to fenugreek seeds imported from Africa. However, there has been no isolation of the causative strain O104:H4 from any of the samples of fenugreek seeds analyzed. Following the German outbreak, we conducted a large sampling to analyze the presence of STEC, EAEC, and other types of diarrheagenic E. coli strains in Spanish vegetables. During June and July 2011, 200 vegetable samples from different origins were analyzed. All were negative for the virulent serotype O104:H4 and only one lettuce sample (0.6%) was positive for a STEC strain of serotype O146:H21 (stx1, stx2), considered of low virulence. Despite the single positive case, the hygienic and sanitary quality of Spanish vegetables proved to be quite good. In 195 of the 200 samples (98%), <10 colony-forming units (cfu) of E. coli per gram were detected, and the microbiological levels of all samples were satisfactory (<100 cfu/g). The samples were also negative for other pathotypes of diarrheagenic E. coli (EAEC, ETEC, tEPEC, and EIEC). Consistent with data from other countries, STEC belonging to serotype O157:H7 and other serotypes have been isolated from beef, milk, cheese, and domestic (cattle, sheep, goats) and wild (deer, boar, fox) animals in Spain. Nevertheless, STEC outbreaks in Spain are rare (AU)
No disponible
Assuntos
Humanos , Escherichia coli/isolamento & purificação , Surtos de Doenças , Sorotipagem/métodos , Infecções por Escherichia coli/epidemiologia , Escherichia coli O157/isolamento & purificação , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
A collection of 69 eae-positive strains expressing 29 different intimin types and eight tir alleles was characterized with respect to their adherence patterns to HeLa cells, ability to promote actin accumulation in vitro, the presence of bfpA alleles in positive strains, and bundle-forming pilus (BFP) expression. All of the nine typical enteropathogenic Escherichia coli (tEPEC) studied harbored the enteropathogenic E. coli adherence factor (EAF) plasmid, as shown by PCR and/or EAF probe results. In addition, they were positive for bfpA, as shown by PCR, and BFP expression, as confirmed by immunofluorescence (IFL) and/or immunoblotting (IBL) assays. Localized adherence (LA) was exclusively displayed by those nine tEPEC, while localized-adherence-like (LAL) was the most frequent pattern among atypical EPEC (aEPEC) and Shiga-toxinproducing E. coli (STEC). All LA and LAL strains were able to cause attaching and effacing (AE) lesions, as established by means of the FAS test. There was a significant association between the presence of tir allele alpha1 and bfpA-positive strains, and consequently, with the LA pattern. However, intimin type or bfpA was not associated with the adherence pattern displayed in HeLa cells. Among the eight bfpA alleles detected, a new type (beta10; accession number FN391178) was identified in a strain of serotype O157:H45, and a truncated variant (beta3.2-t; accession number FN 391181) in four strains belonging to different pathotypes (AU)
No disponible
Assuntos
Humanos , Aderência Bacteriana , Actinas/metabolismo , Escherichia coli Enteropatogênica/patogenicidade , Escherichia coli Shiga Toxigênica/patogenicidade , Alelos , Fímbrias Bacterianas/fisiologia , Proteínas de Escherichia coli/genética , DNA Bacteriano/genética , Genótipo , Células HeLa , Microscopia de Fluorescência , Reação em Cadeia da Polimerase , PlasmídeosRESUMO
Stool specimens of patients with diarrhea or other gastrointestinal alterations who were admitted to Xeral-Calde Hospital (Lugo, Spain) were analyzed for the prevalence of typical and atypical enteropathogenic Escherichia coli (EPEC). Atypical EPEC strains (eae+ bfp-) were detected in 105 (5.2%) of 2015 patients, whereas typical EPEC strains (eae+ bfp+) were identified in only five (0.2%) patients. Atypical EPEC strains were (after Salmonella) the second most frequently recovered enteropathogenic bacteria. In this study, 110 EPEC strains were characterized. The strains belonged to 43 O serogroups and 69 O:H serotypes, including 44 new serotypes not previously reported among human EPEC. However, 29% were of one of three serogroups (O26, O51, and O145) and 33% belonged to eight serotypes (O10:H-, O26:H11, O26:H-, O51:H49, O123:H19, O128:H2, O145:H28, and O145:H-). Only 14 (13%) could be assigned to classical EPEC serotypes. Fifteen intimin types, namely, alpha1 (6 strains), alpha2 (4 strains), beta1 (34 strains), xiR/b2 (6 strains), gamma1 (13 strains), gamma2/q (16 strains), delta/k (5 strains), epsilon1 (9 strains), nuR/e2 (5 strains), zeta (6 strains), iota1 (1 strain), muR/iota2 (1 strain), nuB (1 strain), xiB (1 strain), and o (2 strains), were detected among the 110 EPEC strains, but none of the strains was positive for intimin types mu1, mu2, lambda, or muB. In addition, in atypical EPEC strains of serotypes O10:H-, O84:H-, and O129:H-, two new intimin genes (eae-nuB and eae-o) were identified. These genes showed less than 95% nucleotide sequence identity with existing intimin types. Phylogenetic analysis revealed six groups of closely related intimin genes: (i) alpha1, alpha2, zeta, nuB, and o; (ii) iota1 and muR/iota2; (iii) beta1, xiR/beta2B, delta/beta2O, and kappa; (iv) epsilon1, xiB, eta1, eta2, and nuR/epsilon2; (v) gamma1, muB, gamma2, and theta; and (vi) lambda. These results indicate that atypical EPEC strains belonging to large number of serotypes and with different intimin types might be frequently isolated from human clinical stool samples in Spain (AU)
En este estudio hemos analizado la prevalencia de Escherichia coli enteropatógenas (ECEP) típicas y atípicas en las muestras fecales de pacientes con diarrea y otras alteraciones gastrointestinales del Complexo Hospitalario Xeral-Calde de Lugo (España). Las ECEP atípicas (eae+ bfp-)se detectaron en 105 (5.2%) de los 2015 casos investigados, mientras que lasECEP típicas (eae+ bfp+) se identificaron en solamente cinco (0.2%) pacientes. Las ECEP atípicas fueron los segundos enteropatógenos más frecuentemente aislados después de Salmonella. Un total de 110 cepas de ECEP fueron caracterizadas en este estudio. Las cepas de ECEP pertenecían a 43 serogrupos O y 69 serotipos O:H, entre los cuales había 44 nuevos serotipos no encontrados previamente entre ECEP humanas. No obstante, el 29% de las cepas se pudieron englobar en tres serogrupos (O26, O51 y O145) y el 33% pertenecían a 8 serotipos (O10:H-, O26:H11, O26:H-, O51:H49, O123:H19,O128:H2, O145:H28 y O145:H-). Únicamente 14 (13%) cepas presentaron serotipos de ECEP clásicos. Se detectaron 15 tipos de intiminas entre las 110 cepas de ECEP examinadas: α1 (6 cepas), α2 (4 cepas), β1 (34 cepas), ξR/β2 (6 cepas), γ1 (13 cepas), γ2/θ (16 cepas), δ/κ (5 cepas), ε1 (9 cepas),νR/ε2 (5 cepas), ζ (6 cepas), ι1 (1 cepa), μR/ι2 (1 cepa), νB (1 cepa), ξB(1 cepa) y ο (2 cepas). No se encontró ninguna cepa con las intiminas η1,η2, λ, o μB. Además, en cepas de ECEP atípicas de los serotipos O10:H-, O84:H- y O129:H- se identificaron dos nuevos tipos de genes que codifican intiminas (eae-νB y eae-ο) y que mostraron menos de un 95% de identidad en su secuencia nucleótidica con las de otros tipos de intiminas. El análisis filogenético reveló que los genes que codifican los diferentes tipos de intiminas se pueden englobar en seis grupos: (i) α1, α2, ζ, νB, ο; (ii) ι1, μR/ι2;(iii) β1, ξR/β2B, δ/β2O, κ; (iv) ε1, ξB, η1, η2, νR/ε2; (v) γ1, μB, γ2, θ; (vi) λ. En conclusión, nuestros resultados indican que en muestras clínicas humanasen España podrían aislarse con frecuencia ECEP atípicas pertenecientes a un amplio margen de serotipos y con diferentes tipos de intiminas (AU)