Journal of clinical microbiology
-
J. Clin. Microbiol. · Oct 2018
Depressed Gamma Interferon Responses and Treatment Outcomes in Tuberculosis Patients: a Prospective Cohort Study.
Immunosuppression induced by Mycobacterium tuberculosis is important in the pathogenesis of active tuberculosis (TB). However, the impact of depressed TB-specific and non-TB-specific gamma interferon (IFN-γ) response on the treatment outcomes of TB patients remains uncertain. In this prospective cohort study, culture- or pathology-proven active TB patients were enrolled and QuantiFERON-TB Gold In-Tube (QFT-GIT) assays were performed before the initiation of anti-TB treatment. ⋯ In multivariate analysis, depressed non-TB-specific IFN-γ response was an independent factor associated with 2-month sputum culture nonconversion (odds ratio [OR], 2.49; 95% CI [95% confidence interval], 1.05 to 5.90) and on-treatment mortality (hazard ratio [HR], 2.76; 95% CI, 1.15 to 6.62). In contrast, depressed TB-specific IFN-γ responses were significantly associated with higher on-treatment mortality in univariate analysis but not in multivariate analysis. Our findings suggest that depressed non-TB-specific responses, but not TB-specific IFN-γ responses, as measured by QFT-GIT before the initiation of anti-TB treatment, were significantly associated with worse treatment outcomes in TB patients.
-
J. Clin. Microbiol. · Oct 2018
Lower Airway Bacterial Colonization Patterns and Species-Specific Interactions in Chronic Obstructive Pulmonary Disease.
Little is known about interactions between nontypeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa in the lower respiratory tract in chronic obstructive pulmonary disease (COPD) patients. We characterized colonization by these four bacterial species, determined species-specific interactions, and estimated the effects of host factors on bacterial colonization among COPD patients. We conducted a prospective cohort study in veterans with COPD that involved monthly clinical assessment and sputum cultures with an average duration of follow-up of 4.5 years. ⋯ Associations were similar during stable and exacerbation visits. Recent antimicrobial therapy was associated with a lower prevalence of S. pneumoniae, H. influenzae, and M. catarrhalis, but not P. aeruginosa Our findings support the presence of specific interspecies interactions between common bacteria in the lower respiratory tracts of COPD patients. Further work is necessary to elucidate the mechanisms of these complex interactions that shift bacterial species.