Quantitative real-time polymerase chain reaction for enteropathogenic Escherichia coli: a tool for investigation of asymptomatic versus symptomatic infections

2.50
Hdl Handle:
http://hdl.handle.net/10757/556075
Title:
Quantitative real-time polymerase chain reaction for enteropathogenic Escherichia coli: a tool for investigation of asymptomatic versus symptomatic infections
Authors:
Barletta, Francesca; Ochoa, Theresa J.; Mercado, Erik H.; Ruiz, Joaquim; Ecker, Lucie; Lopez, Giovanni; Mispireta, Monica; Gil, Ana I.; Lanata, Claudio F.; Cleary, Thomas G.
Publisher:
Oxford University Press
Journal:
Clinical Infectious Diseases (Clin Infect Dis)
Issue Date:
30-May-2015
URI:
http://hdl.handle.net/10757/556075
DOI:
10.1086/648069.
PubMed ID:
22028433
PubMed Central ID:
PMC3214587
Additional Links:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3214587/
Abstract:
BACKGROUND: Enteropathogenic Escherichia coli (EPEC) strains are pediatric pathogens commonly isolated from both healthy and sick children with diarrhea in areas of endemicity. The aim of this study was to compare the bacterial load of EPEC isolated from stool samples from children with and without diarrhea to determine whether bacterial load might be a useful tool for further study of this phenomenon. METHODS: EPEC was detected by polymerase chain reaction (PCR) of colonies isolated on MacConkey plates from 53 diarrheal and 90 healthy children aged <2 years. DNA was isolated from stool samples by cetyltrimethylammonium bromide extraction. To standardize quantification by quantitative real-time PCR (qRT-PCR), the correlation between fluorescence threshold cycle and copy number of the intimin gene of EPEC E2348/69 was determined. RESULTS: The detection limit of qRT-PCR was 5 bacteria/mg stool. The geometric mean load in diarrhea was 299 bacteria/mg (95% confidence interval [CI], 77-1164 bacteria/mg), compared with 29 bacteria/mg (95% CI, 10-87 bacteria/mg) in control subjects (P = .016). Bacterial load was significantly higher in children with diarrhea than in control subjects among children <12 months of age (178 vs 5 bacteria/mg; P = .006) and among children with EPEC as the sole pathogen (463 vs 24 bacteria/mg; P = .006). CONCLUSIONS: EPEC load measured by qRT-PCR is higher in diarrheal than in healthy children. qRT-PCR may be useful to study the relationship between disease and colonization in settings of endemicity.
Type:
info:eu-repo/semantics/article
Rights:
info:eu-repo/semantics/openAccess
Language:
eng
Description:
theresa.j.ochoa@uth.tmc.edu; Article
Keywords:
Asymptomatic Diseases; Bacterial Load; Cohort Studies; Diarrhea; Enteropathogenic Escherichia coli/; Escherichia coli Infections
ISSN:
1058-4838
EISSN:
1537-6591

Full metadata record

DC FieldValue Language
dc.contributor.authorBarletta, Francescaes_PE
dc.contributor.authorOchoa, Theresa J.es_PE
dc.contributor.authorMercado, Erik H.es_PE
dc.contributor.authorRuiz, Joaquimes_PE
dc.contributor.authorEcker, Luciees_PE
dc.contributor.authorLopez, Giovannies_PE
dc.contributor.authorMispireta, Monicaes_PE
dc.contributor.authorGil, Ana I.es_PE
dc.contributor.authorLanata, Claudio F.es_PE
dc.contributor.authorCleary, Thomas G.es_PE
dc.date.accessioned2015-05-30T17:26:05Zes_PE
dc.date.available2015-05-30T17:26:05Zes_PE
dc.date.issued2015-05-30es_PE
dc.identifier.issn1058-4838es_PE
dc.identifier.pmid22028433es_PE
dc.identifier.doi10.1086/648069.es_PE
dc.identifier.urihttp://hdl.handle.net/10757/556075es_PE
dc.descriptiontheresa.j.ochoa@uth.tmc.edues_PE
dc.descriptionArticlees_PE
dc.description.abstractBACKGROUND: Enteropathogenic Escherichia coli (EPEC) strains are pediatric pathogens commonly isolated from both healthy and sick children with diarrhea in areas of endemicity. The aim of this study was to compare the bacterial load of EPEC isolated from stool samples from children with and without diarrhea to determine whether bacterial load might be a useful tool for further study of this phenomenon. METHODS: EPEC was detected by polymerase chain reaction (PCR) of colonies isolated on MacConkey plates from 53 diarrheal and 90 healthy children aged <2 years. DNA was isolated from stool samples by cetyltrimethylammonium bromide extraction. To standardize quantification by quantitative real-time PCR (qRT-PCR), the correlation between fluorescence threshold cycle and copy number of the intimin gene of EPEC E2348/69 was determined. RESULTS: The detection limit of qRT-PCR was 5 bacteria/mg stool. The geometric mean load in diarrhea was 299 bacteria/mg (95% confidence interval [CI], 77-1164 bacteria/mg), compared with 29 bacteria/mg (95% CI, 10-87 bacteria/mg) in control subjects (P = .016). Bacterial load was significantly higher in children with diarrhea than in control subjects among children <12 months of age (178 vs 5 bacteria/mg; P = .006) and among children with EPEC as the sole pathogen (463 vs 24 bacteria/mg; P = .006). CONCLUSIONS: EPEC load measured by qRT-PCR is higher in diarrheal than in healthy children. qRT-PCR may be useful to study the relationship between disease and colonization in settings of endemicity.eng
dc.formatapplication/pdfes_PE
dc.language.isoenges_PE
dc.publisherOxford University Presses_PE
dc.relation.urlhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3214587/es_PE
dc.rightsinfo:eu-repo/semantics/openAccesses_PE
dc.sourceUniversidad Peruana de Ciencias Aplicadas (UPC)es_PE
dc.sourceRepositorio Académico - UPCes_PE
dc.subjectAsymptomatic Diseaseses_PE
dc.subjectBacterial Loades_PE
dc.subjectCohort Studieses_PE
dc.subjectDiarrheaes_PE
dc.subjectEnteropathogenic Escherichia coli/es_PE
dc.subjectEscherichia coli Infectionses_PE
dc.titleQuantitative real-time polymerase chain reaction for enteropathogenic Escherichia coli: a tool for investigation of asymptomatic versus symptomatic infectionses_PE
dc.typeinfo:eu-repo/semantics/articlees_PE
dc.identifier.eissn1537-6591es_PE
dc.identifier.journalClinical Infectious Diseases (Clin Infect Dis)es_PE
dc.identifier.pmcidPMC3214587es_PE
dc.description.fundingFinancial support. This work was supported by a Public Health Service award (grants 1K01TW007405 to T. J. O. and R01-HD051716 to T. G. C.) from the National Institutes of Health; by Agencia Espan˜ola de Cooperacio´n Internacional para el Desarrollo, Spain (D/019499/08 and D/024648/09 to J. R. and T. J. O.); and by Dr Lanata’s Institutional Research Funds. Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.es_PE
dc.description.peer-reviewRevisión por pareses_PE
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