Does radiographic evidence of prior pulmonary tubercular infection influence the choice of empiric antibiotics for community-acquired pneumonia in a tuberculosis-endemic area?

BACKGROUND/PURPOSE: Recent medical literature suggests that use of fluoroquinolones (FQs) might be associated with the delayed diagnosis of pulmonary tuberculosis (TB). The purpose of this study was to assess the impact of radiographic evidence of prior pulmonary TB infection on empiric antibiotic choice in cases of community-acquired pneumonia (CAP), as well as the effect of antibiotic regimens on clinical outcome. METHODS: A total of 280 patients with CAP between 1 May and 31 December 2007 were included in the study and their medical records were retrospectively reviewed. Patients were divided into two groups: those receiving FQs (FQ group) or those receiving ß-lactam-based regimens (ß-lactam group). Their demographic data, underlying diseases, clinical features, diseases severity and outcomes were compared. RESULTS: Radiographic evidence of a previous pulmonary TB infection (odds ratio = 3.507, 95% confidence interval = 1.422-8.645; p = 0.006) was an independent factor associated with ß-lactam-based regimens. Patients with a modified pneumonia severity index (mPSI) category V were more likely to receive FQ therapy (odds ratio = 2.53, 95% confidence interval = 1.140-5.615; p = 0.022). Of the patients with mPSI category V, the 14-day mortality rate of those in the ß-lactam group was significantly lower than that of those in the FQ group (0%vs. 23%, respectively; p = 0.044). CONCLUSION: Radiographic evidence of a previous pulmonary TB infection and a lower mPSI score increases the probability of the selection of a ß-lactam-based regimen for the treatment of CAP.

Bacteremic community-acquired pneumonia due to Klebsiella pneumoniae: clinical and microbiological characteristics in Taiwan, 2001-2008.

BACKGROUND: Klebsiella pneumoniae is the major cause of community-acquired pyogenic infections in Taiwan. This retrospective study evaluated the clinical and microbiological characteristics of bacteremic community-acquired pneumonia due to K. pneumoniae in Taiwanese adults. METHODS: The clinical characteristics of bacteremic community-acquired pneumonia (CAP) in adults due to K. pneumoniae were compared to those of adults with bacteremic CAP due to Streptococcus pneumoniae at a tertiary medical center in Taiwan from 2001-2008. Risk factors for mortality of bacteremic CAP due to K. pneumoniae were analyzed. All clinical isolates of K. pneumoniae were examined for capsular serotypes, hypermucoviscosity phenotype, aerobactin and rmpA gene. RESULTS: K. pneumoniae was the dominant cause of bacteremic CAP and was associated with a more fulminant course and a worse prognosis than bacteremic CAP due to Streptococcus pneumoniae. Initial presentation with septic shock and respiratory failure were independent risk factors for both early and total mortality. Serotype K1 and K2 comprised around half of all isolates. There were no significant differences in the clinical characteristics of patients with bacteremic CAP due to K1/K2 and non-K1/K2 isolates. Hypermucoviscosity phenotype as well as the aerobactin and rmpA genes were highly prevalent in the K. pneumoniae isolates. CONCLUSIONS: K. pneumoniae continued to be the dominant cause of bacteremic CAP in Taiwanese adults during 2001-2008. Initial presentation with septic shock and respiratory failure were independent risk factors for both early and total mortality from K. pneumoniae bacteremic CAP. Serotypes K1/K2 comprised around half of all isolates, but did not predispose patients to a poor clinical outcome. Physicians should be aware of the poor prognosis of any patient with bacteremic K. pneumoniae CAP and monitor these patients more closely.

Clinical and microbiological characteristics of Chryseobacterium indologenes bacteremia.

BACKGROUND/PURPOSE: Reports detailing bacteremia caused by Chryseobacterium indologenes remain limited, with most cases reported in Taiwan. The clinical significance of C. indologenes has not been fully established. This retrospective study investigated the clinical features and antimicrobial susceptibility of C. indologenes bacteremia. METHODS: Patients with C. indologenes bacteremia were identified at a medical center/teaching hospital in northern Taiwan between January 1, 2004 and January 31, 2008. Clinical features and the antimicrobial susceptibilities of these patients were analyzed. RESULTS: Sixteen isolates of C. indologenes from 16 episodes in 16 patients were identified, with all patients having underlying diseases. Two patients (12.5%) had polymicrobial bacteremia. The portal of bacteremia was not determined in most cases. Other clinical syndromes included catheter-related bacteremia, urinary tract infection and peritonitis. The majority of patients had undergone invasive procedures. Other associated conditions included immunosuppression, neutropenia and prolonged use of antibiotics. Only three patients were treated with appropriate antibiotics according to minimum inhibitory concentrations. The susceptibilities of isolates to trimethoprim-sulfamethoxazole (75.0%), levofloxacin (62.5%), piperacillin-tazobactam (50.0%), ciprofloxacin (43.75%) and cefepime (12.5%) were variable and the bacteremia-related mortality rate was 6.25%. CONCLUSION: C. indologenes isolates are resistant to multiple antibiotics, with newer fluoroquinolones and trimethoprim-sulfamethoxazole possibly representing the most appropriate antimicrobial agents to treat infections caused by this pathogen. However, the pathogenicity and factors of virulence for C. indologenes remain unclear, with our study revealing favorable outcomes of C. indologenes bacteremia. Epidemiological surveillance of this organism in Taiwan and extensive worldwide surveillance programs are required.