Identification of patterns of transmission of Salmonella within swine production systems using pulsed field gel electrophoresis (PFGE) and repetitive sequence polymerase chain reaction (REP-PCR): a quantitative analysis.
Pulsed field gel electrophoresis (PFGE) using 3 enzymes (Spe I, Xba I, Avr II) and repetitive sequence polymerase chain reaction (REP-PCR) with 3 primers (BOX, ERIC, REP) were compared with respect to their validity as a method for identifying transmission of Salmonella on swine farms. Sixty-eight isolates of Salmonella were obtained from feces of swine, cats, mice, and birds, insect body parts, water and floor samples, and boot scrapings collected on 9 swine farms in Illinois USA. Genetic distances between isolates were calculated using the Dice matching coefficient. Cluster analysis of distance matrices was conducted using the UPG-MA algorithm. There was no significant difference between PFGE and REP-PCR in the genetic diversity detected; however, REP-PCR differentiated between 14 pairs of isolates which PFGE identified as identical. There were no significant differences between PFGE and REP-PCR in identifying all or most close genetic links as isolates from the same farm, the same building, and from the same sampling visit, suggesting ecological validity for both methods. Thus, REP-PCR should be considered as an acceptable and perhaps preferable alternative to PFGE as a genotyping method for studies of Salmonella transmission.
Weigel
R M
RM
Department of Veterinary Pathobiology, University of Illinois, 2001 South Lincoln Avenue, Urbana, Illinois, USA. weigel@uiuc.edu
Qiao
B
B
Barber
D A
DA
Teferedegne
B
B
Kocherginskaya
S
S
White
B A
BA
Isaacson
R E
RE
D000818:Animals; D016000:Cluster Analysis; D017931:DNA Primers; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods / Q000662:veterinary*; D005838:Genotype; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D015203:Reproducibility of Results; D012475:Salmonella / Q000145:classification / Q000235:genetics*; D012481:Salmonella Infections, Animal / Q000635:transmission*; D013553:Swine Diseases / Q000635:transmission*
D017931:DNA Primers