Compliance of Clinical Microbiology Laboratories in the United States with Current Recommendations for Processing Respiratory Tract Specimens from Patients with Cystic Fibrosis

Abstract

Respiratory tract specimens from patients with cystic fibrosis (CF) require unique processing by clinical microbiology laboratories to ensure detection of all potential pathogens. The present study sought to determine the compliance of microbiology laboratories in the United States with recently published recommendations for CF respiratory specimens. Microbiology laboratory protocols from 150 of 190 (79%) CF care sites were reviewed. Most described the use of selective media for Burkholderia cepacia complex (99%), Staphylococcus aureus (82%), and Haemophilus influenzae (89%) and identified the species of all gram-negative bacilli (87%). Only 52% delineated the use of agar diffusion assays for susceptibility testing of Pseudomonas aeruginosa. Standardizing laboratory practices will improve treatment, infection control, and our understanding of the changing epidemiology of CF microbiology.The most common cause of morbidity and mortality in patients with cystic fibrosis (CF) is chronic lung infections caused by Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae and, less commonly, by the Burkholderia cepacia complex. As the life expectancy for CF patients has increased, emerging pathogens such as Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and nontuberculous mycobacteria are increasingly detected (21).Accurate identification of potential pathogens from the respiratory tract of CF patients is critical to ensure appropriate treatment and infection control and to improve our understanding of the changing epidemiology of CF microbiology (3,4,14,23). The present study assessed compliance of clinical microbiology laboratories associated with CF care sites in the United States with recent consensus guidelines for processing CF respiratory tract specimens (21).In 2001, the Cystic Fibrosis Foundation (CFF) in the United States convened a multidisciplinary committee to update previous recommendations for clinical microbiology practices for CF respiratory tract specimens (20). Revised recommendations were categorized by the strength of published evidence (7); category IA recommendations were supported by well-designed experimental, clinical, or epidemiologic studies and category IB recommendations were supported by some experimental, clinical, or epidemiologic studies and a strong theoretical rationale. In May 2003, the new guidelines were published and disseminated to CF care site directors (21).To assess compliance with category 1A and 1B recommendations, the study team sought to obtain a copy of the clinical microbiology laboratory protocols of 190 CF care sites by mailing a request to the clinical directors of 116 core CF care centers (those programs that met CFF criteria for clinical care, teaching, and research), 46 affiliate centers, 24 adult centers, and 4 outreach programs. As many as three requests were made from July 2003 to January 2004. If a site did not send its protocol, its laboratory was contacted. In a final attempt to secure protocols, the CFF sent as many as three e-mails f...

Is there value in susceptibility testing ofPseudomonas aeruginosacausing chronic infection in patients with cystic fibrosis?

“…As a result, the US Cystic Fibrosis Foundation recommended that disk diffusion or E-test be the method of choice for susceptibility testing of this organism [15]. However, in a recent survey of microbiology laboratories servicing US CF centers, only a little over half (52%) were following this recommendation [16].…”

“…Unfortunately, practices in the clinical microbiology laboratory have not kept pace, as evidenced by close to half of the laboratories performing P. aeruginosa susceptibility testing using methods associated with very major errors [13,16]. With increasing use of aerosolized therapy, laboratories must be able to provide susceptibility results for both tobramycin and colistin at both aerosol-and serum-achievable levels.…”

Screening of photochemically grafted polymer films for compatibility with osteogenic precursor cells

“…Several studies have shown that conventional biochemical tests can misidentify B. cepacia complex species, biochemical inactive and newly emerging CF pathogens [6,33]. Thus, laboratories processing CF specimens need access to molecular identification tools and/or in equivocal cases the possibility to send specimens and/or isolates to national or international referral laboratories on CF microbiology [34]. Services regarding the genomic species identification of B. cepacia complex isolates are available by the European Burkholderia cepacia complex…”

Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update

“…and Aspergillus spp.). 41 Thus, the majority of clinical laboratories processing the CF respiratory tract specimens have standardized their techniques, use appropriate selective media and prolonged incubation, and identify gram-negative organisms to the species level. The CF Foundation recommends continued use of the methods described in the 2003 Infection Control Guideline for CF for when to perform respiratory tract cultures, how to transport specimens, and the use of selective media.…”