title: Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, South India.
abstract: BACKGROUND
  Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections.
  
  
  METHODS
  Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC.
  
  
  RESULTS
  Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05).
  
  
  CONCLUSIONS
  Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.
authors.affiliation: School of Marine Sciences, Cochin University of Science and Technology, Cochin, Kerala, India. divyapsbio@gmail.com.
authors.forename: Divya
authors.initials: D
authors.lastname: Sukumaran
authors.forename: Abdulla A
authors.initials: AA
authors.lastname: Mohamed Hatha
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000235:genetics; D063366:Estuaries; D006801:Humans; D007194:India; D008826:Microbial Sensitivity Tests; D014329:Tropical Climate; D037521:Virulence Factors / Q000235:genetics*; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D037521:Virulence Factors