1823. Succession of Non-mucoid Pseudomonas aeruginosa by Mucoid Strains Influences Fungal Colonization in Cystic Fibrosis
Session: Poster Abstract Session: Respiratory Infections: Potpourri
Saturday, October 10, 2015
Room: Poster Hall
  • ID_Week_CF_Fungi_150814[1].pdf (330.7 kB)
  • Background: Lung disease in cystic fibrosis (CF) is an exemplar of bacterial-fungal interactions. The pattern of fungal-pseudomonal co-colonization/infection and its change with time is uncertain. Here we study the associations of fungal (non-Candida) colonization with Pseudomonas and with Pseudomonas phenotype (mucoid and nonmucoid).

    Methods: Sputum from 288 adults from four Australian CF units was cultured by standardised protocols. P. aeruginosa phenotype was identified by routine phenotypic methods and fungi by phenotypic/molecular methods.

    Results: Of 288 patients (60% male, median age 26y; 49% DF508/DF508 genotype), 81 (28%) yielded at least one fungus at enrolment. Aspergillus fumigatus (67%) was the most common followed by Penicillium (15%) and Scedosporium (14%); A. flavus (n=3), A. nidulans, A. niger and A. terreus (n=1 each) were uncommon as were dematiaceous fungi (n=4), other hyaline hyphomycetes (n=3) and Trichosporon spp. (n=2).

    Isolated bacteria (287 patients) included P. aeruginosa (83%) including from 78% of those yielding a fungus. Of those colonized/infected by Pseudomonas, 14% yielded only nonmucoid, 45% both phenotypes and 41%, only mucoid, P. aeruginosa. The Table shows the odds ratios of associations of isolation of P. aeruginosa phenotype by fungus type.

    Conclusion: Of patients from whom only nonmucoid P. aeruginosa is isolated, overall there is increased likelihood of isolation of fungi (non-Candida) but no significant difference in the isolation of A. fumigatus. As CF lung disease progresses with appearance of mucoid P. aeruginosa, the likelihood of isolation of fungi including A. fumigatus is reduced suggesting that fungi compete poorly with the mucoid phenotype.


    Odds ratios (95% CI) of P. aeruginosa phenotype vs. fungus type

    P. aeruginosa phenotype(s)

    ANY fungus


    A. fumigatus



    ANY fungus excluding A. fumigatus


    ANY P. aeruginosa (n=238)



    (0.19 – 0.76)


    ONLY nonmucoid



    (1.10 – 4.75)






    (0.31 – 0.96)


    (0.16 – 0.69)


    ANY mucoid



    (0.26 – 0.78)


    (0.18 – 0.62)


    ONLY mucoid





    *ns=not significant

    Belinda Chapman, PhD1, Shuyao Duan, MPH2, Peter Middleton, PhD MD3, Wieland Meyer, PhD2, Douglas Dorahy, PhD4, Peter Wark, PhD MD5, Shilpa Patel, MD6, Sarah Kidd, PhD7, Sally Chapman, MD8, Hugh Greville, MD8, Michelle Wood, BPhty9, Scott Bell, PhD, MD10, Narelle George, BSc11, Graeme Nimmo, MD11, Karen Mckay, PhD12, Peter Cooper, MD12, Heather Saddington, BNGrad. dip13, Joyce Cheney, MAppSc13, Claire Wainwright, MD PhD13, Tania Sorrell, MD14 and Sharon Chen, PhD MD15, (1)Infectious Diseases, Westmead Millennium Insitute, Westmead, Australia, (2)Infectious Diseases, Westmead Millennium Institute, Westmead, Australia, (3)Respiratory Medicine, Westmead Hospital, Westmead, Australia, (4)Respiratory Medicine, John Hunter Hospital, New Lambton, Australia, (5)John Hunter Hospital, New Lambton, Australia, (6)Westmead Millennium Institute, Westmead, Australia, (7)SA Pathology, Adelaide, Australia, (8)Royal Adelaide Hospital, Adelaide, Australia, (9)Prince Charles Hospital, Brisbane, Australia, (10)Prince charles Hospital, Brisbane, Australia, (11)Pathology Queensland, Brisbane, Australia, (12)The Children's Hospital, Westmead, Australia, (13)Royal Children's Hospital, Brisbane, Australia, (14)Westmead Hospital, Westmead, Australia, (15)Infectious Diseases and Microbiology, Westmead Hospital, Sydney, NSW, Australia


    B. Chapman, None

    S. Duan, None

    P. Middleton, None

    W. Meyer, None

    D. Dorahy, None

    P. Wark, Pfizer Australia: Investigator , Research support

    S. Patel, None

    S. Kidd, None

    S. Chapman, None

    H. Greville, None

    M. Wood, None

    S. Bell, Pfizer Australia: Investigator , Research grant

    N. George, None

    G. Nimmo, None

    K. Mckay, None

    P. Cooper, Pfizer Australia: Investigator , Research support

    H. Saddington, None

    J. Cheney, None

    C. Wainwright, Pfizer Australia: Investigator , Research support

    T. Sorrell, Pfizer Australia: Investigator , Research support

    S. Chen, Pfizer Australia: Grant Investigator and Investigator , Research support

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.