Mei- Lin

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.

Bacteremia in Patients with Hematological Malignancies

Background: An appropriate regimen in the empirical therapy of neutropenic fever episodes must be individualized at each institution. Hospitals have different patterns of microbial isolates and antibiotic resistance that must be taken into account. The aim of this study was to investigate isolates of bacteremia and their antibiotic susceptibility in patients with hematological malignancies. Methods: All positive blood cultures at a medical center in Taiwan between 1999 and 2002 from patients with hematological malignancies were evaluated. Eleven kinds of antibiotics were tested for antimicrobial activities. The risk factors for mortality were evaluated. Results: Three hundred seventy-one episodes of bacteremia in 266 patients with hematological malignancies were recorded. Gram-negative bacilli (GNB) were still predominant and accounted for 78.2% of isolates, followed by gram-positive cocci for 20.8% of isolates, and anaerobes for 1% of isolates. Escherichia coli was the most common isolated organism accounting for 27.5% of GNB isolates. Other isolates included Klebsiella pneumoniae (19.3%), Pseudomonas aeruginosa (11%), and Enterobacter cloacae (10.1%). The most isolated microorganisms were susceptible to cefoperazone/sulbactam, piperacillin/tazobactam, cefepime or imipenem. Age, GNB microorganism and inadequate empirical antibiotics were risk factors. Conclusions: We suggest that cefoperazone/sulbactam, piperacillin/tazobactam, cefepime or imipenem is an ideal empirical therapy.

Clinical and microbiological analysis of Elizabethkingia meningoseptica bacteremia in adult patients in Taiwan.

A limited number of reports have documented bacteremia caused by Elizabethkingia meningoseptica (Chryseobacterium meningosepticum) in adults. Most cases have occurred in Taiwan. This study investigated the clinical features and risk factors for mortality from E. meningoseptica bacteremia and the antimicrobial susceptibilities of the isolates. Patients with E. meningoseptica bacteremia were retrospectively analyzed at a medical center/teaching hospital in northern Taiwan over a 3-y period. We analyzed clinical features and outcomes of patients and antimicrobial susceptibilities and pulsed-field gel electrophoresis (PFGE) results of the isolates. 28 patients had nosocomial bacteremia and 4 patients had healthcare associated bacteremia. The isolates exhibited variable susceptibilities to levofloxacin, ciprofloxacin, piperacillin-tazobactam, tigecycline, and trimethoprim-sulfamethoxazole. PFGE demonstrated that most isolates were epidemiologically unrelated. The 28-d mortality rate was 41%. Multivariate analysis indicated that shock and use of inappropriate antibiotics were independent risk factors for mortality. In conclusion, nosocomial bloodstream infection due to E. meningoseptica is an increasing problem in Taiwan. Our study indicates that patients with E. meningoseptica bacteremia face poor prognoses, with shock and use of inappropriate antibiotics as the main risk factors for mortality. Further clinical study is needed to establish the optimal therapy for E. meningoseptica bacteremia.

Prognostic factors and clinical features of non-typhoid Salmonella bacteremia in adults.

Background: Infections caused by non‐typhoid Salmonella (NTS) have increased, and the increasing incidence of multidrug‐resistant NTS bacteremia in adult patients has also been noted. This study aimed to investigate the clinical and microbiological characteristics of NTS bacteremia. Methods: A total of 71 episodes of NTS bacteremia among 65 patients were identified between 2004 and 2006. Clinical characteristics were collected from medical records. The agar dilution method described by the Clinical and Laboratory Standards Institute was used to determine the in vitro activities of each antibiotic. Multiple logistic regression analysis was used to evaluate the relationship between patient characteristics and all other covariates studied for prognosis. Results: Salmonella enteritidis was isolated in 30 cases (42.3%), Salmonella typhimurium in 22 (31.0%), and Salmonella choleraesuis in 19 (26.7%). Thirty‐two (45.1%) isolates of 71 NTS bacteremias were susceptible to chloramphenicol, 37 (52.1%) to ampicillin, 47 (66.2%) to trimethoprim/sulfamethoxazole (TMP/SMX), 56 (78.9%) to moxifloxacin, 57 (80.3%) to ciprofloxacin and levofloxacin, and 71 (100%) to ceftriaxone. The crude 30‐day mortality rate was 19.7%. In multiple logistic regression analysis, the following variables were independent and significant predictors of mortality: coma (odds ratio, 12.03) and inadequate antibiotic treatment (odds ratio, 6.63). Conclusion: S. enteritidis was the most frequently isolated serotype. High resistance rates of NTS to some readily available antimicrobials (ampicillin, chloramphenicol, TMP/SMX, fluoroquinolones) were found. Patients with the factor of coma or inadequate antibiotic treatment had poor prognosis.

Tigecycline and colistin susceptibility of Chryseobacterium meningosepticum isolated from blood in Taiwan

Sir, Chryseobacterium meningosepticum is a non-glucoseermenting, Gram-negative, aerobic bacillus widely distributed in oil, plants and water. It is not normally present as part of the human icroflora [1]. Clinical disease associated with C. meningosepticum nfection primarily occurs in premature newborns and infants. previous study described meningitis in 84% of clinical cases, ith a 57% mortality rate [1]. Adult C. meningosepticum infection s rare and primarily occurs in severely immunocompromised atients [1]. Chryseobacterium meningosepticum can cause a variety f infections in adults and many cases have been reported in aiwan [2–4]. Several studies have described broad resistance to any Gram-negative antimicrobials, including extended-spectrum ephalosporins, aztreonam, carbapenems and aminoglycosides 5–7]. However, C. meningosepticum displayed variable suscepibility to Gram-positive antimicrobials, including rifampicin, lindamycin, erythromycin, trimethoprim/sulfamethoxazole, uinolones and vancomycin [5–7]. Chryseobacterium meningosepicum infections were generally associated with a poor outcome in everal studies, with a cumulative mortality of 33% among posteonates [1]. A recent Taiwanese study revealed a high mortality ate (42.9%) in patients with hospital-acquired C. meningosepticum nfection [4]. Tigecycline exhibits in vitro activity against many Gram-positive nd Gram-negative microorganisms, including multiresistant

Successful treatment of Aerococcus viridans endocarditis in a patient allergic to penicillin

Aerococcus viridans is a rare human pathogen that occasionally causes endocarditis. Most of the reported cases of endocarditis have been treated with penicillin. Here we describe a patient who was allergic to penicillin and was successfully treated with cefotaxime.

Prognostic factors of candidemia among nonneutropenic adults with total parenteral nutrition

BACKGROUND Immediate removal of central venous catheters (CVCs) is not possible in patients with candidemia requiring total parenteral nutrition (TPN). This study analyzed the possible prognostic factors for survival time after onset of candidemia among nonneutropenic adults requiring TPN. METHODS We conducted a retrospective analysis from September 2003 to August 2005. RESULTS A total of 59 nonneutropenic adults with candidemia and requiring TPN were identified retrospectively. All Candida isolates were susceptible to flucytosine and amphotericin B. With the exception of one C glabrata isolate, all other isolates were susceptible to fluconazole and itraconazole. The only predictor of 30-day survival rate after onset of candidemia identified in our analysis was an Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 23 points or less. Adults with higher APACHE II scores, who did not have their CVCs changed, did not receive antifungal treatment, or who had thrombocytopenia had shorter survival times after the onset of candidemia. CONCLUSIONS APACHE II scores, thrombocytopenia, antifungal agents, and CVCs changes are associated with survival time in nonneutropenic adults requiring TPN after the onset of candidemia.