BACKGROUND: Although we gain new knowledge, the problem of pneumonia will not be eliminated. We should understand who is at risk, why these people develop this problem, what causes the pneumonia, and how to manage and prevent respiratory infection. To clarify the alterations of the etiologies of bacterial pneumonia we analysed the recent causative organisms and evaluated the therapeutic implications. METHODS: A retrospective four-year study of bacterial pneumonia was conducted in Soon Chun Hyang University Hospital. 190 episodes of bacterial pneumonia was investigated. RESULTS: 1) The causative organisms were isolated in 173 cases on the sputum culture: 154 cases (89%) were gram negative bacilli and 19 cases(ll%) were gram positive cocci. The major organisms were Pseudomonas species 49 cases(28%), Klebsiella pneumoniae 29 cases(17%), Enterobacter species 25 cases(14%), and Acinetobacter species 20 cases(12%) in decreasing order. Pseudomonas species(13 cases, 34%) were frequently found in nosocomial pneumonia. 2) The causative organisms were isolated in 16 cases on the blood culture: 7 cases(43%) were gram negative bacilli and 9 cases(57%) were gram positive cocci. The major organisms were Staphylococcus aureus(6 cases, 38%), Pseudomonas species(3 cases, 19%) in decreasing order. 3) In the susceptibility test of causative organisms to antimicrobial drugs, Pseudomonas was susceptible to amikacin, ciprofloxacin, aztreonam, ceftazidime(more than 50%) and resistant to piperacillin, gentamicin, carbenicillin(more than 60%). Klebsiella was susceptible to chloramphenicol, gentamicin, cefotetan(more than 70%) and resistant to carbenicillin, ampicillin(more than 70%). Staphylococcus was susceptible to methiciilin(64%), and Streptococcus pneumoniae was susceptible to oxacillin(94%). 4) The response rate after antibiotics therapy was 81% and the mortality rate was 19%. CONCLUSION: As considering the changes of causative organisms and antibiotic resistance, it behooves us to exercise caution in dispending antibiotics in order to maximize their continued efficacy and to do appropiate antibiotics therapy based on cultures and susceptibility test.
Acinetobacter ; Amikacin ; Anti-Bacterial Agents ; Aztreonam ; Carbenicillin ; Chloramphenicol ; Ciprofloxacin ; Drug Resistance, Microbial ; Enterobacter ; Gentamicins ; Gram-Positive Cocci ; Klebsiella ; Klebsiella pneumoniae ; Mortality ; Piperacillin ; Pneumonia ; Pneumonia, Bacterial* ; Pseudomonas ; Retrospective Studies ; Sputum ; Staphylococcus ; Streptococcus pneumoniae

Purpose: The purpose of this study was to identify the concordant or discordant genomic profiling between primary and matched metastatic tumors in patients with colorectal cancer (CRC) and to explore the clinical implication. Materials and Methods: Surgical samples of primary and matched metastatic tissues from 158 patients (335 samples) with CRC at Korea University Anam Hospital were evaluated using the Ion AmpliSeq Cancer Hotspot Panel. We compared genetic variants and classified them as concordant, primary-specific, and metastasis-specific variants. We used a combination of principal components analysis and clustering to find genomic groups. Kaplan-Meier curves were used to appraise survival between genomic groups. We used machine learning to confirm the correlation between genetic variants and metastatic sites. Results: A total of 282 types of deleterious non-synonymous variants were selected for analysis. Of a total of 897 variants, an average of 40% was discordant. Three genomic groups were yielded based on the genomic discrepancy patterns. Overall survival differed significantly between the genomic groups. The poorest group had the highest proportion of concordant KRAS G12V and additional metastasis-specific SMAD4. Correlation analysis between genetic variants and metastatic sites suggested that concordant KRAS mutations would have more disseminated metastases. Conclusion Driver gene mutations were mostly concordant; however, discordant or metastasis-specific mutations were present. Clinically, the concordant driver genetic changes with additional metastasis-specific variants can predict poor prognosis for patients with CRC.