title: Intraclonal genetic diversity amongst cystic fibrosis and keratitis isolates of Pseudomonas aeruginosa.
abstract: Given the emergence of transmissible strains of Pseudomonas aeruginosa, such as the Liverpool epidemic strain (LES), in cystic fibrosis (CF) centres, it is important to carry out regular surveillance of isolates. In a survey of 22 P. aeruginosa isolates, each from a different CF patient identified as negative for LES in a paediatric centre in Liverpool, six (23 %) were identified as being the same clone type (clone D) using array-tube genotyping. Using a series of alternative genotyping approaches [PFGE, random amplification of polymorphic DNA (RAPD), variable number of tandem repeats (VNTR) and multilocus sequence typing (MLST)], the six CF clone D isolates and eight previously identified clone D isolates associated with infections leading to keratitis were compared. All but two of the clone D isolates (both keratitis-associated) were assigned by MLST to sequence type 235 and were highly similar using VNTR analysis. However, there was considerable variation found among the isolates when using PFGE or RAPD, highlighting the limitations of these methods. The discordance with respect to two of the isolates identified by array-tube genotyping as clone D, when using all the other typing methods, emphasizes the need to use more than one method for reliable identification of strains.
authors.affiliation: Institute of Infection and Global Health, University of Liverpool, Liverpool L69 3BX, UK.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Hall
authors.affiliation: Institute of Infection and Global Health, University of Liverpool, Liverpool L69 3BX, UK.
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Fothergill
authors.affiliation: St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kaye
authors.affiliation: Department of Medical Microbiology, Royal Liverpool University Hospital, Liverpool L7 8XP, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Neal
authors.affiliation: Alder Hey Children's Hospital, Liverpool L12 2AP, UK.
authors.forename: Paul S
authors.initials: PS
authors.lastname: McNamara
authors.affiliation: Alder Hey Children's Hospital, Liverpool L12 2AP, UK.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Southern
authors.affiliation: Institute of Infection and Global Health, University of Liverpool, Liverpool L69 3BX, UK.
authors.forename: Craig
authors.initials: C
authors.lastname: Winstanley
mesh_terms: D015373:Bacterial Typing Techniques; D002648:Child; D003550:Cystic Fibrosis / Q000382:microbiology*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007634:Keratitis / Q000382:microbiology*; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D011552:Pseudomonas Infections / Q000150:complications / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000302:isolation & purification*; D019105:Random Amplified Polymorphic DNA Technique