title: Identification of diarrheagenic Escherichia coli isolated from infants and children in Dar es Salaam, Tanzania.
abstract: BACKGROUND
  Relatively few studies have been done in Tanzania to detect and classify diarrheagenic Escherichia coli (DEC) strains among children with diarrhea. This study aimed at investigating DEC among children in Dar es Salaam aged less than five years hospitalized due to acute/persistent diarrhea.
  
  
  METHODS
  DEC were isolated from stool samples collected from two hundred and eighty children with acute/persistent diarrhea at Muhimbili National Hospital and Ilala and Mwananyamala Municipal Hospitals in Dar es Salaam. A multiplex PCR system method was used to detect a species specific gene for E.coli and ten different virulence genes for detection of five pathogroups of DEC namely enteroaggregative- (EAEC), enteropathogenic- (EPEC), enterotoxigenic- (ETEC), enteroinvasive- (EIEC) and enterohemorghagic- Escherichia coli (EHEC).
  
  
  RESULTS
  Sixty-four patients (22.9%) harbored DEC. Forty-one of them (14.6%) were categorized as EAEC. Most of the EAEC (82.9%) were classified as typical EAEC possessing the aggR gene, and 92.6% carried the aat gene. Isolates from thirteen patients were EPEC (4.6%) and most of these (92.3%) were typical EPEC with both eae and bfpA genes. Ten isolates were identified as ETEC (3.6%) with only the heat stable toxin; either st1a or st1b but not both. Age wise, EAEC and EPEC were significantly more prevalent among the age group 0-6 months (p < 0.05). Genes for EHEC (stx1 and stx2) and EIEC (ial) were not detected in this study group.
  
  
  CONCLUSIONS
  The results show a high proportion of DEC among Tanzanian children with diarrhea, with typical EAEC and typical EPEC predominating. The use of primers for both variants of ST1 (st1a and st1b) increased the sensitivity for detection of ETEC strains.
authors: Department of Microbiology and Immunology, School of Medicine, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania. sabmoyo26@yahoo.com
authors: Sabrina J
authors: SJ
authors: Moyo
authors: Samwel Y
authors: SY
authors: Maselle
authors: Mecky I
authors: MI
authors: Matee
authors: Nina
authors: N
authors: Langeland
authors: Haima
authors: H
authors: Mylvaganam
mesh_terms: D000208:Acute Disease; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003968:Diarrhea, Infantile / Q000382:microbiology*; D004403:Dysentery / Q000453:epidemiology* / Q000382:microbiology; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000145:classification / Q000453:epidemiology*; D005798:Genes, Bacterial; D006801:Humans; D007223:Infant; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D013636:Tanzania / Q000453:epidemiology; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors
references: J Clin Microbiol. 2000 Jan;38(1):7-12
references: 10618054
references: FEMS Microbiol Lett. 2006 Jan;254(1):12-8
references: 16451173
references: New Microbiol. 2001 Jan;24(1):77-83
references: 11209846
references: J Clin Microbiol. 2002 Apr;40(4):1254-8
references: 11923341
references: Epidemiol Infect. 2002 Aug;129(1):49-55
references: 12211596
references: J Clin Microbiol. 2003 May;41(5):2138-40
references: 12734261
references: Bull World Health Organ. 2003;81(3):197-204
references: 12764516
references: Bull World Health Organ. 2003;81(4):236
references: 12764488
references: J Med Microbiol. 2003 Nov;52(Pt 11):1015-9
references: 14532347
references: J Biol Chem. 2003 Nov 14;278(46):45680-9
references: 12933818
references: Am J Trop Med Hyg. 2003 Oct;69(4):406-10
references: 14640501
references: J Clin Microbiol. 2004 Jan;42(1):133-9
references: 14715743
references: Am J Trop Med Hyg. 2004 May;70(5):536-9
references: 15155987
references: J Med Microbiol. 2004 Nov;53(Pt 11):1137-44
references: 15496393
references: Bull World Health Organ. 1977;55(4):489-98
references: 304391
references: Bull World Health Organ. 1982;60(4):605-13
references: 6982783
references: Infect Immun. 1983 Mar;39(3):1167-74
references: 6341230
references: Rev Infect Dis. 1990 Jan-Feb;12 Suppl 1:S41-50
references: 2406855
references: Infect Immun. 1992 Jun;60(6):2297-304
references: 1350273
references: Epidemiol Infect. 1992 Oct;109(2):283-9
references: 1397116
references: Bull World Health Organ. 1992;70(6):705-14
references: 1486666
references: Trans R Soc Trop Med Hyg. 1993 Dec;87 Suppl 3:49-53
references: 8108852
references: J Bacteriol. 1994 Aug;176(15):4691-9
references: 7913930
references: J Clin Microbiol. 1995 May;33(5):1054-9
references: 7615704
references: J Infect Dis. 1996 Sep;174(3):675-7
references: 8769640
references: J Clin Microbiol. 1997 May;35(5):1103-7
references: 9114389
references: Clin Microbiol Rev. 1998 Jan;11(1):142-201
references: 9457432
references: J Bacteriol. 1999 Mar;181(6):1779-85
references: 10074069
references: J Infect Dis. 2000 Jan;181(1):252-60
references: 10608774