title: Use of Selective Fungal Culture Media Increases Rates of Detection of Fungi in the Respiratory Tract of Cystic Fibrosis Patients.
abstract: The prevalence of fungi in the respiratory tracts of cystic fibrosis (CF) patients has risen. However, fungal surveillance is not routinely performed in most clinical centers in the United States, which may lead to an underestimation of the true prevalence of the problem. We conducted a prospective study comparing the rates of detection for clinically important fungi (CIF), defined asAspergillus,Scedosporium, andTrichosporonspecies andExophiala dermatitidis, in CF sputa using standard bacterial and selective fungal culture media, including Sabouraud dextrose agar with gentamicin (SDA), inhibitory mold agar (IMA), and brain heart infusion (BHI) agar with chloramphenicol and gentamicin. We described the prevalence of these fungi in an adult CF population. A total of 487 CF respiratory samples were collected from 211 unique participants. CIF were detected in 184 (37.8%) samples. Only 26.1% of CIF-positive samples were detected in bacterial culture medium, whereas greater rates of detection for fungi were found in IMA (65.8%;P< 0.001), in SDA (at 30°C, 64.7%;P= 0.005), and in BHI agar (63.0%;P= 0.001). The prevalences ofAspergillusandScedosporiumspecies were 40.8% and 5.2%, respectively, which are greater than the nationally reported prevalence numbers of 20.4% and 1.9%. Selective fungal culture media and longer incubation periods yielded higher rates of detection for CIF in CF sputum samples compared with that detected in bacterial culture medium, resulting in an underdetection of fungi by bacterial culture alone. The prevalence of fungi in CF may be better estimated by using selective fungal culture media, and this may translate to important clinical decisions.
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: Gina
authors.initials: G
authors.lastname: Hong
authors.affiliation: Johns Hopkins School of Medicine, Department of Pathology, Division of Microbiology, Baltimore, Maryland, USA.
authors.forename: Heather B
authors.initials: HB
authors.lastname: Miller
authors.affiliation: Johns Hopkins School of Medicine, Department of Medicine, Division of Pulmonary and Critical Care Medicine, Baltimore, Maryland, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Allgood
authors.affiliation: Johns Hopkins Hospital, Microbiology Laboratory, Baltimore, Maryland, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Lee
authors.affiliation: Johns Hopkins School of Medicine, Department of Medicine, Division of Pulmonary and Critical Care Medicine, Baltimore, Maryland, USA.
authors.forename: Noah
authors.initials: N
authors.lastname: Lechtzin
authors.affiliation: Johns Hopkins School of Medicine, Department of Pathology, Division of Microbiology, Baltimore, Maryland, USA szhang28@jhmi.edu.|Johns Hopkins Hospital, Microbiology Laboratory, Baltimore, Maryland, USA.
authors.forename: Sean X
authors.initials: SX
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003470:Culture Media / Q000737:chemistry*; D003550:Cystic Fibrosis / Q000150:complications*; D005260:Female; D005658:Fungi / Q000145:classification* / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008828:Microbiological Techniques / Q000379:methods*; D008875:Middle Aged; D009181:Mycoses / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D011446:Prospective Studies; D012137:Respiratory System; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D003470:Culture Media
keywords: Aspergillus; Exophiala; Sabouraud dextrose agar; Scedosporium; Trichosporon; brain heart infusion agar; cystic fibrosis; fungal culture; fungi; inhibitory mold agar