RESUMO
Enteroaggregative Escherichia coli (EAEC) comprises an important diarrheagenic pathotype, while uropathogenic E. coli (UPEC) is the most important agent of urinary tract infection (UTI). Recently, EAEC virulence factors have been detected in E. coli strains causing UTI, showing the importance of these hybrid-pathogenic strains. Previously, we detected an E. coli strain isolated from UTI (UPEC-46) presenting characteristics of EAEC, e.g., the aggregative adherence (AA) pattern and EAEC-associated genes (aatA, aap, and pet). In this current study, we analyzed the whole genomic sequence of UPEC-46 and characterized some phenotypic traits. The AA phenotype was observed in cell lineages of urinary and intestinal origin. The production of curli, cellulose, bacteriocins, and Pet toxin was detected. Additionally, UPEC-46 was not capable of forming biofilm using different culture media and human urine. The genome sequence analysis showed that this strain belongs to serotype O166:H12, ST10, and phylogroup A, harbors the tet, aadA, and dfrA/sul resistance genes, and is phylogenetically more related to EAEC strains isolated from human feces. UPEC-46 harbors three plasmids. Plasmid p46-1 (~135 kb) carries some EAEC marker genes and those encoding the aggregate-forming pili (AFP) and its regulator (afpR). A mutation in afpA (encoding the AFP major pilin) led to the loss of pilin production and assembly, and notably, a strongly reduced adhesion to epithelial cells. In summary, the genetic background and phenotypic traits analyzed suggest that UPEC-46 is a hybrid strain (UPEC/EAEC) and highlights the importance of AFP adhesin in the adherence to colorectal and bladder cell lines.
Assuntos
Infecções por Escherichia coli , Proteínas de Escherichia coli , Infecções Urinárias , Escherichia coli Uropatogênica , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Feminino , Proteínas de Fímbrias/genética , Humanos , Masculino , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/metabolismo , alfa-FetoproteínasRESUMO
Enteropathogenic Escherichia coli (EPEC) are important human gastroenteritis agents. The prevalence of six non-LEE genes encoding type 3 translocated effectors was investigated. The nleC, cif and nleB genes were more prevalent in typical than in atypical EPEC, although a higher diversity of genes combinations was observed in atypical EPEC.
Assuntos
Sistemas de Secreção Bacterianos/genética , Escherichia coli Enteropatogênica/genética , Proteínas de Escherichia coli/genética , Variação Genética , Fosfoproteínas/genética , Fatores de Virulência/genética , Escherichia coli Enteropatogênica/classificação , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Gastroenterite/microbiologia , HumanosRESUMO
Enteropathogenic Escherichia coli (EPEC) are important human gastroenteritis agents. The prevalence of six non-LEE genes encoding type 3 translocated effectors was investigated. The nleC, cif and nleB genes were more prevalent in typical than in atypical EPEC, although a higher diversity of genes combinations was observed in atypical EPEC.
Assuntos
Humanos , Sistemas de Secreção Bacterianos/genética , Escherichia coli Enteropatogênica/genética , Proteínas de Escherichia coli/genética , Variação Genética , Fosfoproteínas/genética , Fatores de Virulência/genética , Escherichia coli Enteropatogênica/classificação , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Gastroenterite/microbiologiaRESUMO
Four of six adhesin-encoding genes (lpfA, paa, iha, and toxB) from Shiga toxin-producing Escherichia coli strains were detected in typical and atypical enteropathogenic E. coli (EPEC) strains of various serotypes. Although the most prevalent gene was lpfA in both groups, paa was the only potential diarrhea-associated gene in atypical EPEC.
Assuntos
Adesinas de Escherichia coli/genética , Escherichia coli Enteropatogênica/genética , Escherichia coli Shiga Toxigênica/genética , Fatores de Virulência/genética , Adesinas de Escherichia coli/isolamento & purificação , Adulto , Aderência Bacteriana , Criança , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Humanos , Reação em Cadeia da Polimerase , SorotipagemRESUMO
The presence of the pathogenicity island (PAI) O122 genes, efa1 (lifA), sen, pagC, nleB, and nleE, in typical and atypical enteropathogenic Escherichia coli (EPEC) strains was investigated. The simultaneous occurrence of all genes was statistically associated with diarrhea due to atypical EPEC. Detection of the complete PAI O122 could aid in the identification of potential pathogenic strains of atypical EPEC.
Assuntos
DNA Bacteriano/genética , Escherichia coli Enteropatogênica/genética , Infecções por Escherichia coli/microbiologia , Ilhas Genômicas , Diarreia/microbiologia , Escherichia coli Enteropatogênica/isolamento & purificação , Proteínas de Escherichia coli/genética , Humanos , Prevalência , Fatores de Virulência/genéticaRESUMO
To analyze whether Escherichia coli strains that cause urinary tract infections (UPEC) share virulence characteristics with the diarrheagenic E. coli (DEC) pathotypes and to recognize their genetic diversity, 225 UPEC strains were examined for the presence of various properties of DEC and UPEC (type of interaction with HeLa cells, serogroups and presence of 30 virulence genes). No correlation between adherence patterns and serogroups was observed. Forty-five serogroups were found, but 64% of the strains belonged to one of the 12 serogroups (O1, O2, O4, O6, O7, O14, O15, O18, O21, O25, O75, and O175) and carried UPEC virulence genes (pap, hly, aer, sfa, cnf). The DEC genes found were: aap, aatA, aggC, agg3C, aggR, astA, eae, ehly, iha, irp2, lpfA(O113), pet, pic, pilS, and shf. Sixteen strains presented aggregative adherence and/or the aatA sequence, which are characteristics of enteroaggregative E. coli (EAEC), one of the DEC pathotypes. In summary, certain UPEC strains may carry DEC virulence properties, mostly associated to the EAEC pathotype. This finding raises the possibility that at least some faecal EAEC strains might represent potential uropathogens. Alternatively, certain UPEC strains may have acquired EAEC properties, becoming a potential cause of diarrhoea.