title: Potential pathogens, antimicrobial patterns and genotypic diversity of Escherichia coli isolates in constructed wetlands treating swine wastewater.
abstract: Escherichia coli populations originating from swine houses through constructed wetlands were analyzed for potential pathogens, antimicrobial susceptibility patterns, and genotypic diversity. Escherichia coli isolates (n = 493) were screened for the presence of the following virulence genes: stx1, stx2 and eae (Shiga toxin-producing E. coli [STEC]), heat-labile enterotoxin (LT) genes and heat stable toxin STa and STb (enterotoxigenic E. coli (ETEC), cytotoxin necrotizing factors 1 and 2 (cnf1 and cnf2 [necrotoxigenic E. coli- NTEC]), as well as O and H antigens, and the presence of the antibiotic resistance genes blaTEM, blaSHV, blaCMY-2, tet A, tet B, tet C, mph(A), aadA, StrA/B, sul1, sul2 and sul3. The commensal strains were further screened for 16 antimicrobials and characterized by BOX AIR-1 PCR for unique genotypes. The highest antibiotic resistance prevalence was for tetracycline, followed by erythromycin, ampicillin, streptomycin, sulfisoxazole and kanamycin. Our data showed that most of the isolates had high distribution of single or multidrug-resistant (MDR) genotypes. Therefore, the occurrence of MDR E. coli in the wetland is a matter of great concern due to possible transfer of resistance genes from nonpathogenic to pathogenic strains or vice versa in the environment.
authors.affiliation: USDA-ARS, U. S. Salinity Laboratory, 450 W. Big Springs Rd, Riverside, CA 92507, USA Mark.Ibekwe@ars.usda.gov.
authors.forename: A M
authors.initials: AM
authors.lastname: Ibekwe
authors.affiliation: Department of Animal and Veterinary Sciences, California State Polytechnic University, Pomona, CA 91768, USA.
authors.forename: Shelton E
authors.initials: SE
authors.lastname: Murinda
authors.affiliation: E. coli Reference Center, Pennsylvania State University, State College, PA 16802, USA.
authors.forename: Chitrita
authors.initials: C
authors.lastname: DebRoy
authors.affiliation: Department of Natural Resources and Environmental Design, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA.
authors.forename: Gudigopura B
authors.initials: GB
authors.lastname: Reddy
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents; D001427:Bacterial Toxins / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004768:Enterotoxins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D013552:Swine; D037521:Virulence Factors / Q000235:genetics*; D062065:Wastewater / Q000382:microbiology; D053833:Wetlands
chemical_list: D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D037521:Virulence Factors; D062065:Wastewater; C060296:cytotoxic necrotizing factor type 1; C073819:eaeA protein, E coli; C027538:heat-labile enterotoxin, E coli
keywords: BOX AIR-1; E. coli; antimicrobial; constructed wetland; contaminants