ABSTRACT
BACKGROUND: Helicobacter pylori ClariRes assay is a novel commercially available real-time PCR assay allowing H. pylori detection and clarithromycin susceptibility testing in either gastric biopsy or stool specimens. OBJECTIVE: The aim of this study was to validate the novel biprobe real-time assay in stool specimens from 217 dyspeptic children. METHODS: DNA from gastric biopsies and stool specimens were obtained and submitted to the biprobe real time assay for H. pylori detection and clarithromycin susceptibility testing. RESULTS: The sensitivity, specificity, and test accuracy were 69, 100 and 93.9% for the detection of H. pylori infection and 83.3, 100 and 95.6%, for detection of clarithromycin resistance. CONCLUSION: This assay proved to be appropriate for H. pylori clarithromycin susceptibility testing, particularly in children populations where a high prevalence of clarithromycin-resistant strains is suspected.
Subject(s)
Clarithromycin/pharmacology , Helicobacter Infections/diagnosis , Helicobacter Infections/microbiology , Helicobacter pylori/drug effects , Helicobacter pylori/isolation & purification , Molecular Diagnostic Techniques/methods , Polymerase Chain Reaction/methods , Adolescent , Anti-Bacterial Agents/pharmacology , Brazil , Child , Child, Preschool , Feces/microbiology , Female , Gastric Mucosa/microbiology , Helicobacter pylori/genetics , Humans , Infant , Male , Microbial Sensitivity Tests/methods , Sensitivity and SpecificityABSTRACT
We isolated 45 Helicobacter pylori strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of cagA, vacA s1m1, iceA2, and babA2 genes.
Subject(s)
Anti-Bacterial Agents/pharmacology , Clarithromycin/pharmacology , Drug Resistance, Bacterial , Helicobacter Infections/epidemiology , Helicobacter pylori/classification , Helicobacter pylori/drug effects , Virulence Factors/genetics , Adhesins, Bacterial/genetics , Adolescent , Antigens, Bacterial/genetics , Bacterial Proteins/genetics , Brazil/epidemiology , Child , Child, Preschool , Female , Genotype , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Helicobacter pylori/genetics , Helicobacter pylori/isolation & purification , Humans , Infant , Male , Prevalence , Severity of Illness IndexABSTRACT
BACKGROUND: We recently observed an association of resistance with a certain enteropathogenic Escherichia coli (EPEC) serotypes and identified a conjugative plasmid, similar to plasmid pED208, that was conserved among archival O111:H2/NM and O119:H2 strains of diverse geographical origin. In this study, we sought to determine the prevalence and distribution of this plasmid among a collection of EPEC isolates from Brazil, as well as to study the susceptibilities of these isolates to antimicrobial agents. RESULTS: Resistance was more commonly seen in typical EPEC than atypical strains. The most prevalent resistances were to ampicillin, tetracycline, streptomycin and the sulfonamides. Markers for the EPEC conjugative multiresistance plasmid, were detected in 21 (30%) of typical but only 4 (5%) of atypical strains (p = 0.001, Chi-squared test). This plasmid, previously reported from only O111 and O119 strains was found in O55 and O127 strains and was associated with the presence of class 1 integrons. CONCLUSION: Our data suggest a limited but expanding host range for the EPEC resistance plasmid.
Subject(s)
Enteropathogenic Escherichia coli/drug effects , Enteropathogenic Escherichia coli/genetics , Escherichia coli Infections/microbiology , Anti-Bacterial Agents/pharmacology , Brazil/epidemiology , Chi-Square Distribution , Child, Preschool , Drug Resistance, Multiple, Bacterial , Enteropathogenic Escherichia coli/isolation & purification , Escherichia coli Infections/epidemiology , Genes, Bacterial , Humans , Microbial Sensitivity Tests , Plasmids/genetics , PrevalenceABSTRACT
Although atypical enteropathogenic Escherichia coli (aEPEC) strains are frequently implicated in childhood diarrhea in developing countries, not much is known about their adherence properties. The phenotypic and genotypic characterization of 29 aEPEC strains expressing the localized adherence-like pattern points toward the involvement of E. coli common pilus (ECP), intimins, and other known E. coli adhesins in this pattern.
Subject(s)
Adhesins, Escherichia coli/biosynthesis , Enteropathogenic Escherichia coli/pathogenicity , Escherichia coli Infections/microbiology , Escherichia coli Proteins/biosynthesis , Hepatocytes/microbiology , Virulence Factors/biosynthesis , Adhesins, Escherichia coli/genetics , Bacterial Typing Techniques , Cell Line , Child , Child, Preschool , Enteropathogenic Escherichia coli/classification , Enteropathogenic Escherichia coli/genetics , Enteropathogenic Escherichia coli/isolation & purification , Escherichia coli Proteins/genetics , Humans , Serotyping , Virulence Factors/geneticsABSTRACT
We describe the characterization of 126 atypical enteropathogenic Escherichia coli (aEPEC) isolates from 1,749 Brazilian children. Classic aEPEC strains were more frequently found in children with diarrhea than in controls (P < 0.001), showing their importance as acute diarrhea agents in our country. Only aEPEC strains carrying either the ehxA or paa gene were significantly associated with diarrhea.
Subject(s)
Diarrhea/microbiology , Enteropathogenic Escherichia coli/classification , Enteropathogenic Escherichia coli/pathogenicity , Escherichia coli Infections/microbiology , Brazil , DNA Primers/genetics , DNA, Bacterial/genetics , Escherichia coli Proteins/genetics , Genotype , Hemolysin Proteins/genetics , Humans , Infant , Serotyping , Virulence Factors/geneticsABSTRACT
A 1-year prospective study was carried out in two large urban centers of São Paulo State, Brazil, to determine the prevalences and roles of the different Escherichia coli pathotypes in children less than 5 years of age with diarrhea presenting to the emergency rooms of public hospitals or visiting private pediatricians' offices. Of the pathotypes sought, typical enteroaggregative and atypical enteropathogenic types of E. coli were isolated for 8.9% and 5.4% of 774 diarrhea cases, respectively, and were found to be dominant and significantly associated with diarrhea.
Subject(s)
Diarrhea/microbiology , Escherichia coli/classification , Child, Preschool , Escherichia coli/isolation & purification , Escherichia coli/pathogenicity , Humans , Infant , Infant, Newborn , Prospective StudiesABSTRACT
A multiplex PCR to differentiate typical and atypical enteropathogenic Escherichia coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC) strains was developed and evaluated. The targets selected for each group were eae and bfpA for EPEC, aggR for EAEC, elt and est for ETEC, ipaH for EIEC and stx for STEC isolates. This PCR was specific and sensitive for rapid detection of target isolates in stools. Among 79 children with acute diarrhea, this technique identified 13 (16.4%) with atypical EPEC, four (5%) with EAEC, three (3.8%) with typical EPEC, one (1.3%) with ETEC and one (1.3%) with EIEC.
