1 / 15

Shigella sonnei Antimicrobial Resistance, Phage Typing And Molecular Characterisation

Shigella sonnei Antimicrobial Resistance, Phage Typing And Molecular Characterisation. Niall DeLappe 1 , D.Morris 2 , S.Fanning 3 , M.Daly 3 , T.Chiesty 4 , F.O’Holloran 3 ,G.Corbett-Feeney 1,2 , M.Cormican 1 ,2 . 1 Interim National Salmonella Reference Laboratory, UCHG.

malina
Download Presentation

Shigella sonnei Antimicrobial Resistance, Phage Typing And Molecular Characterisation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Shigella sonneiAntimicrobial Resistance, Phage Typing And Molecular Characterisation Niall DeLappe1, D.Morris2, S.Fanning3, M.Daly3, T.Chiesty4, F.O’Holloran3 ,G.Corbett-Feeney1,2 , M.Cormican1 ,2. 1Interim National Salmonella Reference Laboratory, UCHG. 2National University of Ireland, Galway 3Cork Institute of Technology. 4LEP, PHLS, Colindale

  2. Abstract

  3. Introduction Dysentery • Amoebicand Bacillary • HistoricallyA dysenteriae 15 serotypes B boydii 18 serotypes C flexneri 6 serotypes & 2 variants D sonnei 1 serotype (5 biotypes) • Evolved from different ancestral strains of E.coli. • Virulence plasmid , Pinv (140 MDa) directs the entry of bacterium into host epithelial cells. • produce various enterotoxins

  4. Shigella sonnei • Evolved from E.coli O62 • Acquired O antigen from Pleisiomonasshigelloides O17 by lateral transfer • Gene cluster for O antigen is located on Pinv. • Incidence USA 1998 25,000 cases 1999 18,000 cases UK approx. 900 cases/year • Spread by person-to-person contact and contaminated food or water • Low infectious dose (10 cells)

  5. Isolates analysed in this study • Galway n = 42 (clusters of 4,2 &2 related) • Mayo n = 9 (cluster of 3 related) • Roscommon n = 8 (cluster of 2 related) • Dublin n = 6 (unknown) • Cork n = 2 (unknown )

  6. Materials and Methods • Pulsed Field Gel Electrophoresis- XbaI • 20 h at 5-50s , 16 h at 5-20s • Phage typing (8 isolates) • Sensitivity testing • NCCLS Disk Diffusion • Plasmid profiling • alkaline lysis method of Kado & Liu • Conjugation- liquid mating • Integron analysis (14 isolates) • PCR

  7. Location of predominant strain Number of Isolates Galway34 Mayo8 Roscommon4

  8. Seasonal Variation of Predominant strain PFGE A, ASSu *(Ampicillin,Streptomycin,Sulphonamide) Results 1998 1999

  9. Pulsed Field Gel Electrophoresis B A A B1 B4 A A A A B4 B3 B1 B B5 B B B5 B B B4 Kb 339.5 291.0 242.5 194.0 145.5 97.0 48.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Restriction patterns interpreted by criteria of Tenover et al

  10. PFGE analysed by Bionumerics PT9 PT9 RDNC PT6 PT50 PT6 PT6

  11. PT 9 PFGE A (n=2) PT6 PFGE B (n=1) PFGE B1 (n=1) PFGE B4 (n=1) PFGE B5 (n=1) PT50 PFGE B3 (n=1) RDNC PFGE B (n=1) Phage Typing of S. sonnei isolates (performed by LEP, Colindale, London) Phage type 6 accounts for approximately 80% of U.K. infections. PT9 is quite rare.

  12. Conjugation of S.sonnei isolates 1 Isolated on Trptone Soya Agar , Oxoid 2 Isolated on Mueller Hinton Agar, BBL A = Ampicillin 100mg/ml agar Na = Nalidixic acid 30mg/ml agar T = Tetracycline 20mg/ml agar Tm = Trimethoprim 5mg/ml agar

  13. Plasmid Profiles B4 A A A A A A A1 A1 B A A B1 B4 pDu Kb 10 8 6 5 4 3 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Most isolates had multiple plasmids ranging in size from 2kb to >50kb

  14. Antibiotic Resistance Patterns Antibiotics tested: Amp10, C 30, S10, Su300, Tet30, W5, Na30, Nt300, K30, Cip5 Oxoid

  15. Conclusions • Majority of isolates tested were from 1 PFGE group, A • Good concurrence between PFGE ,phage typing and resistance typing • High rate of resistance to antibiotics with several being encoded by conjugative plasmids or integrons • It would prove interesting to analyse isolates from other countries

More Related