12 Christensen

download 12 Christensen

If you can't read please download the document

  • date post

    18-Jul-2016
  • Category

    Documents

  • view

    12
  • download

    1

Embed Size (px)

description

Microbiology Lecture

Transcript of 12 Christensen

  • Clinical importance of viridans group

    streptococci and other rare gram-positive cocci

    Endocarditis: native valves, prosthetic valves Immunocompromised: septicemia, pneumonia, antibiotic resistance

    Jens Jrgen Christensen Dept. of clinical microbiology Slagelse Hospital, Slagelse Denmark

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Cytochrome and catalase content and cellular arrangement of facultatively anaerobic gram-positive cocci ______________________________________________________________________________ Genus Cytochrome/ Cellular catalase arrangement ______________________________________________________________________________ Staphylococcus +/+ Clusters Streptococcus -/- Chains Enterococcus -/- Chains Abiotrophia (1) -/- Chains Granulicatella (3) -/- Chains Gemella (7) -/- Pairs or tetrads Lactococcus (5) -/- Chains (Leuconostoc (4) -/- Chains) Pediococcus (3) -/- Pairs or tetrads Aerococcus (7) -/+W Pairs or tetrads Other genera: Facklamia (6), (Rothia (6)

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Identification of fastidious gram-positive cocci

    MALDI-TOF MS applied on non-non hemolytic streptococci: Identification and use of complementary libraries.

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Identification of fastidious gram-positive cocci

    Which genera and species? (16 genera, 51

    species)

    Dolosigranulum Globicatella Facklamia Vagococcus Dolosicoccus Helcococcus Ignavigranum

    Alloiococcus

    (Rothia)

    Abiotrophia Granulicatella Gemella Lactococcus (Leuconostoc) Pediococcus Aerococcus

    Wound

    Blood

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Blood

    Lactococcus (Leuconostoc) Pediococcus

    Abiotrophia Granulicatella Gemella

    Aerococcus

    kd grntsager samt normalflora i tarm

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Challenge strains: n=90

    Aerococcus species (n=35) Gemella species (n=23) Abiotrophia/Granulicatella(n=10; 2/8) Lactococcus species (n=5) Globicatella species (n=5) Leuconostoc species (n=5) Rothia species (n=3) Facklamia, Vagococcus, Helcococcus, Alloiococcus

    ES

    CMID

    Online

    Lectu

    re Lib

    rary

    by a

    uthor

  • ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Parameters indicative of UTI in 92 patients whose urine yielded growth of A. urinae. Number of patients _________________________________________________________________ A. urinae singly A. urinae in admixture Indwelling catheter - + - + _____________________________________________________________________________ Dysuria + fever + pyuria 5 1 6 - Dysuria + fever 2 1 3 - Dysuria + pyuria 13 1 9 3 Fever + pyuria - 1 1 1 Dysuria 3 - 4 - Fever 1 1 - - Pyuria 11 - 8 1 Incontinence - - 2 - No symptoms 1 - 2 - No information 5 - 5 1 ______________________________________________________________________________ TOTAL 41 5 38 6 ______________________________________________________________________________

    Do they mean anything?

    Aerococcus-like organism, a newly recognized potential urinary tract pathogen. JJ Christensen, H Vibits, J Ursing and B Korner. J. Clin. Microbiol. 29:1049-1053, 1991

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Clinical data on 17 patients in Denmark with septicemia/bacteremia caused by A. urinae Clinical Sources of Case no. Age/Sex presentation A. urinae Outcome ____________________________________________________________________________________________ 1 78/M Endocarditis Blood, urine Died with A. urinae in heart valves 2 81/M Endocarditis Blood, urine Died, despite clearing of bacteremia 3 73/M Endocarditis Blood Died with killed A. urinae in vegetation 4 81/M Endocarditis Blood Died with killed A. urinae in vegetation 5 55/F Endocarditis Blood Died of A. urinae infection 6 78/M Endocarditis Blood* Recovered 7 63/M Urosepticemia Blood, urine Recovered 8 76/M Urosepticemia Blood, urine Recovered 9 77/M Urosepticemia Blood, urine Survived infection (eventually died) 10 79/M Urosepticemia Blood Recovered 11 86/F Urosepticemia Blood, urine Recovered 12 73/M Urosepticemia Blood, urine Recovered 13 40/M Urosepticemia Blood, urine Recovered 14 90/M Urosepticemia Blood, urine Recovered 15 37/M Septicemia Blood Recovered 16 82/M Urosepticemia? Blood Survived infection (eventually died) 17 80/M Urosepticemia? Blood Recovered ____________________________________________________________________________________________

    Bacteremia/septicemia due to Aerococcus-like organisms: Report of seventeen cases. JJ Christensen, IP Jensen, J Frk, B Kristensen, R Skov, B Korner and an ALO study group. Clin. Infect. Dis. 21:943-947, 1995.

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Susceptibility patterns of A. urinae

    _________________________________________________________________________ SENSITIVE TO: RESISTANT TO: Penicillin Sulfonamides Ampicillin Trimethoprim Cehalosporins Nalidixic acid Clavulanate Aminoglycocides Erythromycin Mecillinam Clindamycin Vancomycin Teicoplanin Mupirocin Tetracyclines Chloramphenicol

    Aerococcus urinae: A newcomer in clinical and micrbiological practice. JJ Christensen and B Korner. Antimicrobics and Infectious Disease Newsletter. 15: 78-80, 1996

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Instruments for identification

    Semi-automated phenotypic systems Molecular methods MALDI-TOF MS

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Rapid ID 32 Strep system (T. G. Jensen et al. CMI, 1999)

    Phoenix automated system (G. Brigante et al., JCM. 2006)

    VITEK (M. Haanper, et al. JCM, 2007) All the automated identification systems have

    difficulty in identification of NHS to the species level, especially for the Mitis group.

    ??? Automated systems ???

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • API panels, Crystal panels, Vitek cards, MicroScan conventional panels, Phoenix panels, Sensititre panels

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Evaluation of the Rapid ID 32 Strep system Jensen TG, Konradsen HB, Bruun B CMI: 1999,5:417-423

    122 strains: Pyogenic (n=29): 86% correct identification. OK Viridans (n=51): 65% to the species level. Worst for the Mitis group. NOT OK Enterococcal (n=27): 93% Correct identificatopn. OK

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Gene analysis

    16S rRNA gene SodA gene (Magnganese-dependent superoxide dismutase) RnpB gene (RNase P RNA) Tuf gene (elongation factor Tu) GroESL gene (heat shock protein) Rpo gene (beta-subunit of RNA polymearse)

    No single gene analysis is sufficient for species identification. Multi-gene analysis

    - ddl, gdh, rpo, sodA

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Xiaohui Chen Nielsen, KMA, Slagelse Sygehus

    Berridge, B. R. et al. 1998. J. Clin. Microbiol. 36(9):2778-2781

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Oralis cluster

    Mitis-pneumoniae cluster

    FIG. 1. Phylogenetic tree based on ITS sequences of the 11. S. mitis (Smit), 11 S. oralis (Soral) and 17 S. pneumoniae (Spneu) strains using unrooted neighbor joining method. No distinct cluster were formed according to the species. It clearly demonstrates that S. mitis, S. pneumoniae and S. oralis are genetically closely related species and cannot be discriminated from each other based on ITS sequences.

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • The Mitis group contains species that are important clinical pathogens and are geneticallly closely related. The memebers are natural competent for genetic transformation and homologous recombination happened among species

    S. pneumoniae, S. mitis, S. pseudopneumoniae cluster might evolved from the same ancester: pneumoncoccus-like bacteria.

    The memebers have strikingly different pathogenic potentials. S. pneumonae is among the most frequent microbial killers, while S. mitis and S. oralis are the most dominant endocarditis pathogen.

    What is so special about the Mitis group

    Killian et al. 2008. PlosOne 3: 1-11.

    ESCM

    ID On

    line Le

    cture

    Librar

    y

    by a

    uthor

  • Gdh gene: house keeping gene,