Epidemiology and Treatment of Small-colony Variant Staphylococcus Aureus in Cystic Fibrosis
Status:
Withdrawn
Trial end date:
2021-12-01
Target enrollment:
Participant gender:
Summary
Methicillin-susceptible (MSSA) and Methicillin-resistant (MRSA) Staphylococcus aureus (SA)
are two of the most important infectious pathogens in CF, with 69% of CF patients having lung
infection with MSSA or MRSA in the last year. Wolter and co-workers recently demonstrated
that a specific morphologic subtype of MSSA and MRSA, small-colony variant Staph aureus
(SCV-SA), is associated with greater decline in lung function and worse clinical outcomes.
SCV-SA is already recognized for its ability to contribute to persistent infection, likely
due to SCV-SA's ability for intracellular growth, as well as its increased antibiotic
resistance compared to normal-colony SA. To investigate the epidemiology and clinical
significance of SCV-SA in CF, and explore the hypothesis that SCV-SA may require unique
antibiotic treatment strategies to optimize clinical response, the investigators will perform
the following:
1. Characterize the epidemiology of SCV-SA infection in both an adult and pediatric CF
population and investigate the clinical significance of SCV-SA infection in CF by
comparing clinical characteristics and outcomes of CF patients with SCV-SA compared to
those with to normal-colony MSSA/MRSA.
2. Characterize the unique microbiologic characteristics of SCV-SA infection in CF by
evaluating antibiotic susceptibility profiles and molecular characteristics of SCV-SA in
a two large CF patient populations.
3. Perform a 16-patient pilot study of a novel treatment for SCV-SA infection in CF,
utilizing low dose rifampin in combination with standard anti-SA antibiotics.
These investigations will delineate the role of SCV-SA as a pathogen in CF and provide
guidance to optimize treatment strategies of MSSA/MRSA CF lung infection.