title: Comparison of repetitive PCR and pulsed-field gel electrophoresis for the genotyping of Mannheimia haemolytica.
abstract: Mannheimia haemolytica is an opportunistic pathogen that can cause fibrinonecrotic pneumonia in cattle and is the main bacterial agent implicated in bovine respiratory disease-complex (BRD). Despite its economic importance to the cattle industry, few studies have characterized the genetic nature of M. haemolytica and none have genotyped isolates from feedlots. Identifying and monitoring genetic variants of M. haemolytica is important to understanding the etiology of BRD in cattle. We investigated the capacity of three genotyping techniques (BOX-PCR, (GTG)(5)-PCR and PFGE analysis of SalI-restricted DNA) to discriminate among 24 reference strains from the family Pasteurellaceae and 40 M. haemolytica isolates collected from feedlot cattle. From cluster analysis of the M. haemolytica isolates, PFGE was revealed as most discriminating, followed by BOX-PCR and then (GTG)(5)-PCR (Simpson's diversity index >0.98, 0.82, and 0.72, respectively). Of these methods, PFGE also had the greatest mean repeatability (0.96). The PFGE and BOX-PCR assays grouped all M. haemolytica in a single cluster but only BOX-PCR and (GTG)(5)-PCR grouped the Mannheimia glucosida and Mannheimia ruminalis strains together. Refinement of genotyping procedures for M. haemolytica could offer new insight into the etiology of this pathogen in BRD.
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4.
authors.forename: C L
authors.initials: CL
authors.lastname: Klima
authors.forename: T W
authors.initials: TW
authors.lastname: Alexander
authors.forename: L B
authors.initials: LB
authors.lastname: Selinger
authors.forename: R R
authors.initials: RR
authors.lastname: Read
authors.forename: P E
authors.initials: PE
authors.lastname: Shewan
authors.forename: S P
authors.initials: SP
authors.lastname: Gow
authors.forename: C W
authors.initials: CW
authors.lastname: Booker
authors.forename: T A
authors.initials: TA
authors.lastname: McAllister
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques / Q000379:methods*; D002417:Cattle; D016000:Cluster Analysis; D016172:DNA Fingerprinting / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D016978:Mannheimia haemolytica / Q000145:classification* / Q000235:genetics*; D048089:Pneumonia of Calves, Enzootic / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D004269:DNA, Bacterial