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Background Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used in microbial identification. This study evaluated the performance of MALDI-TOF MS and investigated the economic and medical impact of MALDI-TOF MS implementation. Methods A total of 12,202 clinical isolates collected from April to September 2013 were identified using MALDI-TOF MS, and the success rates in identifying isolates were analyzed. The differences in the processing time, cost of consumables, weight of waste, and clinical impact between MALDI-TOF MS and biochemical reaction were compared. Results MALDI-TOF MS successfully identified 96% of 12,202 isolates, including 96.8% of 10,502 aerobes, 90.5% of 1481 anaerobes, 93.8% of 81 yeasts, and 90.6% of 138 nontuberculous mycobacteria at the genus level. By using MALDI-TOF MS, the processing time for aerobes decreased from 32.5 hours to 4.1 hours, and that for anaerobes decreased from 71.5 hours to 46 hours. For detection of aerobes and anaerobes, the cost of consumables was estimated to decrease by US$0.9 per isolate, thus saving US$94,500 in total annual isolation. Furthermore, the weight of waste decreased six-fold, resulting in a reduction of 350 kg/month or 4.2 tons/year. MALDI-TOF MS also increased the percentage of correct antibiotics treatment for Escherichia coli and Klebsiella pneumonia from 56.1% to 75% and shortened the initiation time of the correct antibiotic action from 3.3 hours to 2.5 hours. Conclusions MALDI-TOF MS is a rapid, reliable, economical, and environmentally friendly method for routine microbial identification and may contribute to early appropriate antibiotic treatment in clinical settings.

Background/purposeCarbapenem-resistant Pseudomonas aeruginosa infections have been a challenge and issue in hospital settings. However, the clinical impact of P. aeruginosa blood isolates resistant only to carbapenems has never been discussed previously.MethodsTo assess the risk factors and clinical significance of bacteremia caused by carbapenem resistance only P. aeruginosa (CROPA), a 6-year retrospective case–control study was conducted. The CROPA strains were defined as isolates susceptible to ciprofloxacin, antipseudomonal penicillins and cephalosporins, and aminoglycosides but resistant to one antipseudomonal carbapenem (imipenem or meropenem) or both. The controls were selected among patients with bacteremia due to P. aeruginosa susceptible to all above classes of antipseudomonal antibiotics, which was defined as all-susceptible P. aeruginosa.ResultsTwenty-five patients had at least one blood culture positive for CROPA, and 50 controls had all-susceptible P. aeruginosa bacteremia. CROPA bacteremia had a high 30-day mortality rate (72.0%), as compared to 26.0% for the controls (p

Background/PurposeThe objective of this study was to determine the predictive value of teicoplanin minimal inhibitory concentrations (MICs) for treatment failure among patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia.MethodsIn this study, all patients with ≥1 tracheal aspirates or sputum cultures positive for MRSA admitted to the hospital between April 2011 and September 2011 were reviewed. We enrolled patients who are ≥18 years of age, with a diagnosis of pneumonia, and with a receipt of teicoplanin therapy throughout the course. The relationship between teicoplanin Etest MICs and treatment outcomes of MRSA pneumonia was analyzed to identify the breakpoint of teicoplanin MICs influencing treatment outcomes.ResultsOf the 80 patients enrolled, 31 had a lower teicoplanin MIC level (

The clinical presentations of laboratory-confirmed Bordetella pertussis infection in Chang Gung Children's Hospital during 1997 and 2001 were analyzed. Of the 46 cases, 25 (54.3%) were male. The patients ages ranged from 24 days to 37 years, with a mean and median of 4.3 years and 10.5 years, respectively. Forty four patients had vaccination records, among them 23 patients (52.2%) had receivedor = 3 doses of pertussis vaccine. Of the patients who were partially vaccinated (received 1 or 2 doses vaccine) or unvaccinated, 16 (69.6%) presented with whooping cough, 5 (22.2%) with post-tussive vomiting, and 13 (59.1%) with cyanosis. Leukocytosis (white blood cellsor = 15,000 cells/microL) and lymphocytosis (lymphocytesor = 10,000 cells/microL) were observed in 17 (47.2%) and 16 (44.4%) of the patients, respectively. Fourteen patients (30.4%) developed complications, among which pneumonia was the most common (92.3%). Among infantsor = 1 year of age, 95.2% were partially vaccinated (20/21), compared with 5% (1/20) of the patients1 year of age (p0.05). The overall complication rate was 37.5%, compared with 18.2% for patients1 year of age (p0.05). One 2-month-old patient required ventilatory support after the development of cardiopulmonary failure. There was no mortality in this study. In summary, pertussis most commonly occurred in infants who were unvaccinated or partially vaccinated. These patients usually presented with atypical symptoms such as cyanosis or apnea. The importance of vaccination still cannot be overemphasized because immunized patients usually present with milder disease than those who are not immunized.

Mycobacterium marinum often causes skin infections, tenosynovitis, arthritis, and osteomyelitis, and occasionally results in severe disseminated infections in immunocompromised patients. In this study, the clinical features of 14 cases of M. marinum infection were retrospectively analyzed. One patient had septic arthritis, the other 13 had skin infections and/or tenosynovitis. It usually took 2 months or longer for a definite diagnosis to be made in these patients. Three of the 14 patients were cured using clarithromycin alone or in combination with rifampin plus ethambutol. Most patients did not respond to conventional antituberculosis agents. Pulsed-field gel electrophoresis and infrequent-restriction-site polymerase chain reaction are efficient tools for the molecular typing of M. marinum. Both methods yielded a concordant result, and 4 of 12 isolates were genetically closely related to each other based on their banding patterns. This study indicates that these isolates were derived from the same clone. Because M. marinum infection is curable, early diagnosis is important. Poor healing of wounds after exposure to aquatic animals appears to be the most important clinical clue indicating the need for culture and inclusion of M. marinum infection in the differential diagnosis.