Phenotypic and genotypic analysis of enterotoxigenic Escherichia coli in samples obtained from Egyptian children presenting to referral hospitals.

• Hospital surveillance was established in the Nile River Delta to increase the understanding of the epidemiology of diarrheal disease among Egyptian children. Between September 2000 and August 2003, samples obtained from children less than 5 years of age who had diarrhea and who were seeking hospital care were cultured for enteric bacteria. Colonies from each culture with a morphology typical of that of Escherichia coli were tested for the heat-labile (LT) and heat-stable (ST) toxins by a GM-1-specific enzyme-linked immunosorbent assay and colonization factor (CF) antigens by an immunodot blot assay. Enterotoxigenic E. coli (ETEC) isolates were recovered from 320/1,540 (20.7%) children, and ETEC isolates expressing a known CF were identified in 151/320 (47%) samples. ST CFA/I, ST CS6, ST CS14, and LT and ST CS5 plus CS6 represented 75% of the CFs expressed by ETEC isolates expressing a detectable CF. Year-to-year variability in the proportion of ETEC isolates that expressed a detectable CF was observed (e.g., the proportion that expressed CFA/I ranged from 10% in year 1 to 21% in year 3); however, the relative proportions of ETEC isolates expressing a CF were similar over the reporting period. The proportion of CF-positive ETEC isolates was higher among isolates that expressed ST. ETEC isolates expressing CS6 were isolated significantly less often (P < 0.001) than isolates expressing CFA/I in children less than 1 year of age. Macrorestriction profiling of CFA/I-expressing ETEC isolates by using the restriction enzyme XbaI and pulsed-field gel electrophoresis demonstrated a wide genetic diversity among the isolates that did not directly correlate with the virulence of the pathogen. The genome plasticity demonstrated in the ETEC isolates collected in this work suggests an additional challenge to the development of a globally effective vaccine for ETEC.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

Nyckelord

Bacterial Toxins

biosynthesis

Child

Preschool

Cluster Analysis

DNA Fingerprinting

DNA

Bacterial

metabolism

Deoxyribonucleases

Type II Site-Specific

metabolism

Diarrhea

epidemiology

microbiology

Egypt

epidemiology

Electrophoresis

Gel

Pulsed-Field

Enterotoxigenic Escherichia coli

classification

genetics

isolation & purification

metabolism

Enterotoxins

biosynthesis

Escherichia coli Infections

epidemiology

microbiology

Escherichia coli Proteins

biosynthesis

Fimbriae Proteins

biosynthesis

Genetic Variation

Hospitals

Humans

Infant

Infant

Newborn

Molecular Epidemiology

Polymorphism

Restriction Fragment Length

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)