Ya-Sung Yang

Candida albicans versus non-albicans bloodstream infections: The comparison of risk factors and outcome

BACKGROUNDnCandidemia caused by non-albicans Candida spp. is of special concern because of its high drug resistance and increase in prevalence. In clinical practice, early identification of non-albicans candidemia is crucial. We investigated the outcome in patients with candidemia caused by Candida albicans and Candida non-albicans.nnnMETHODSnWe retrospectively evaluated candidemic patients from October 2007 to July 2009. Underlying diseases, predisposing factors, laboratory data, and outcome were analyzed.nnnRESULTSnOne hundred and eight patients of candidemia were enrolled. Candida albicans and non-albicans spp. were responsible for 56.5% (61 of 108) and 43.5% (47 of 108) of candidemia cases, respectively. Among patients with non-albicans candidemia, significantly more patients had neutropenia (p=0.001) and less patients had candiduria (p=0.001) and intensive care unit stay (p=0.002) in comparison with those with C albicans candidemia. All-cause Day 7 mortality was high in both C albicans and non-albicans spp. candidemia [44.3% (27 of 61) vs. 29.8% (14 of 47)]. Multivariate analysis revealed that poor renal function (oddsxa0ratio, 1.035; 95% confidence interval, 1.001-1.071; p=0.04) and shock (odds ratio, 19.4; 95% confidence interval, 2.53-149.5; p=0.004) are independent risk factors for fatal candidemia.nnnCONCLUSIONSnThe outcome of candidemia was poor. The identified risk factors may help us to differentiate fatal candidemia in early infection.

Impact of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae on the outcome of community-onset bacteremic urinary tract infections.

BACKGROUND/PURPOSEnThe number of community-onset bacteremic urinary tract infections (UTIs) caused by Escherichia coli and Klebsiella pneumoniae is increasing. However, the impact of extended-spectrum β-lactamase (ESBL)-producing E. coli and K. pneumoniae (ESBL-EK) on bacteremic UTI outcomes is unknown. The aim of this study was to retrospectively analyze the impact of ESBL-EK on community-onset bacteremic UTIs.nnnMETHODSnOf the 58 patients enrolled, 12 suffered from ESBL-EK-caused community-onset bacteremic UTIs. Patients were categorized into ESBL (n=12) and non-ESBL (n=46) groups. Diagnosis was based on findings of concurrent bacteremia and bacteriuria caused by the same pathogen on admission.nnnRESULTSnThe ESBL group had significantly more male patients (66.7%vs. 23.9%; p=0.005), indwelling urinary catheters (41.7%vs. 6.5%; p=0.002), patients admitted from other healthcare facilities (50.0%vs. 8.7%; p=0.001), and patients with higher Acute Physiology and Chronic Health Evaluation II scores (23.3±7.1 vs. 15.9±6.3; p=0.001) and intensive care unit admissions (41.7%vs. 4.4%; p=0.003) than the non-ESBL group. Multiple logistic regression analysis revealed that male gender (odds ratio=9.2; 95%, confidence interval=1.7-50.6) and healthcare facility residency (odds ratio=15.5; 95% confidence interval=2.4-98.9) were independent risk factors for ESBL-producer infections among bacteremic UTIs. Although the mortality rate of both groups was similar (8.3%vs. 4.4%; p=0.403), the ESBL group had longer hospital stays (16.3±9.3 days vs. 7.9±5.2 days; p=0.010) and higher antibiotic costs (615.1±423.5 USD vs. 252.8±269.2 USD, p=0.014).nnnCONCLUSIONnMale gender and healthcare facility residency are risk factors for ESBL-producer infections among patients with community-onset bacteremic UTIs. Patients with bacteremic UTIs caused by ESBL-EK also have prolonged hospital stays and higher antibiotic costs. Early detection of ESBLs and appropriate antibiotic coverage are likely to shorten hospital stays and reduce medical costs.

Recurrent Klebsiella pneumoniae Liver Abscess: Clinical and Microbiological Characteristics

ABSTRACT Recurrent Klebsiella pneumoniae liver abscesses (KLAs) are rarely reported. Six cases of recurrent KLAs are characterized. Most of the patients had diabetes and K1 serotype KLAs. All of the isolates were uniformly susceptible to cefazolin. Distinct molecular fingerprints were found for the strains isolated from both primary and recurrent KLAs.

Impact of vancomycin MIC creep on patients with methicillin-resistant Staphylococcus aureus bacteremia

BACKGROUND/PURPOSEnTo date, vancomycin is still the standard treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections, but minimum inhibitory concentration (MIC) creep is becoming a major concern. The aims of this study were to investigate trends in vancomycin use and MIC values over the last decade at our institute and to evaluate the outcomes of bacteremic patients infected with MRSA isolates with reduced vancomycin susceptibility.nnnMETHODSnVancomycin use and density were evaluated using the defined daily doses (DDD) method. Patients with MRSA bacteremia were enrolled retrospectively. Patient demographic data and clinical outcomes were analyzed. The first isolate from each patient was collected for E-testing in order to determine vancomycin MIC. MIC trends were assessed as MIC(50), MIC(90), and the geometric mean.nnnRESULTSnVancomycin use has increased over the last decade. One hundred and forty patients were enrolled and their respective isolates were retrieved, including isolates from 45 patients in 2001, 46 patients in 2005, and 49 patients in 2009. The geometric mean (± standard deviation) of the vancomycin MIC for MRSA isolates obtained in 2009 was 1.39 ± 0.30 μg/mL, which is significantly higher than the mean vancomycin MIC obtained in 2001 (1.19 ± 0.34 μg/mL, p < 0.01) and 2005 (1.99 ± 0.25 μg/mL, p < 0.001). There were no significant differences in terms of the in-hospital mortality rate between patients with MRSA isolates with MICs ≥ 1.5 μg/mL or < 1.5 μg/mL.nnnCONCLUSIONnWe identified a significant upward trend in the use of vancomycin and its MIC over the last decade. This study shows that patients infected with MRSA isolates with high MICs (≥1.5 μg/mL) do not have a significantly higher mortality rate compared with isolates with low MICs (<1.5 μg/mL).

The Emerging Life-threatening Opportunistic Fungal Pathogen Kodamaea ohmeri: Optimal Treatment and Literature Review

BACKGROUND/PURPOSEnThe yeast Kodamaea ohmeri rarely causes life-threatening human infections. However, risk factors, laboratory diagnoses, and treatments for K. ohmeri infection have been limited, and the optimal therapy for K. ohmeri infection has not been identified.nnnMETHODSnTwenty cases of K. ohmeri infection have been reported in the English medical literature. We present two new cases of K. ohmeri fungemia. We investigated the nature and treatment of K. ohmeri infections using minimum inhibitory concentrations of antifungal agents and by comparing the two cases with those described in the literature.nnnRESULTSnFrom March 1998 to December 2008, a total of 22 patients with K. ohmeri infections were studied. Hematological malignancies and diabetes were the most common co-morbidities for K. ohmeri infections, with crude prevalence rates of 27.3% and 18.2%, respectively. The K. ohmeri isolates showed less susceptibility to fluconazole but greater susceptibility to amphotericin B [15/25 isolates (60%) vs. 25/25 isolates (100%), respectively]. Good outcomes (8/9 cases; 88.9%) were found following removal of indwelling catheters and implants. In addition, voriconazole and echinocandins, such as caspofungin and micafungin, also showed excellent minimum inhibitory concentrations against K. ohmeri.nnnCONCLUSIONnK. ohmeri should not be regarded as a contaminant of blood cultures. Favorable outcomes for this potentially life-threatening infection are promoted by the removal of indwelling catheters; furthermore, outcomes are associated with optimal antifungal regimens, especially voriconazole and echinocandins.

Comparison between bacteremia caused by carbapenem resistant Acinetobacter baumannii and Acinetobacter nosocomialis

BackgroundIt is unknown whether there are differences between bacteremia caused by carbapenem resistant Acinetobacter baumannii (CRAB) and carbapenem resistant Acinetobacter nosocomialis (CRAN). This study aims to investigate the differences, especially in clinical outcomes, between patients with bacteremia caused by CRAB or CRAN.MethodsThis is a 9-year retrospective study comparing the clinical manifestations, antimicrobial susceptibilities, and clinical outcomes of 71 patients with CRAB bacteremia and 64 patients with CRAN bacteremia.ResultsPatients with CRAB were more likely to have hematologic malignancies and presented with more shock episodes than those with CRAN. CRAB isolates were more resistant to various classes of antimicrobials except colistin, and therefore the patients with CRAB bacteremia were more likely to receive inappropriate antimicrobial therapies. The 14-day mortality was significantly higher in patients with CRAB (40.8% vs. 14.1%; p = 0.001), and in this study, acquisition of CRAB was identified as an independent risk factor for mortality (odds ratio = 4.003; 95% confidence interval = 1.566-10.231; p = 0.004).ConclusionsCRAB and CRAN bacteremia are different in clinical characteristics, antimicrobial susceptibilities, and mortality rates. Genomic species identification should be performed in the study of carbapenem resistant Acinetobacters to better delineate the role of different species.

Invasive Brevundimonas vesicularis bacteremia: Two case reports and review of the literature

There are few reports of invasive infections caused by Brevundimonas vesicularis. We report two cases of B. vesicularis bacteremia confirmed by culture and 16S rRNA sequence analysis with highly variable sensitivity to broad-spectrum antibiotics. Initial empiric therapy withxa0anti-pseudomonal antibiotics plus trimethoprim-sulfamethoxazole for hospital-acquired B. vesicularis infections should be considered.

Comparisons between patients with trimethoprim-sulfamethoxazole-susceptible and trimethoprim-sulfamethoxazole-resistant Stenotrophomonas maltophilia monomicrobial bacteremia: A 10-year retrospective study.

BACKGROUND/PURPOSEnThe impact of bacteremia due to the resistance of Stenotrophomonas maltophilia to trimethoprim-sulfamethoxazole (TMP-SXT) is uncertain. This study compared the clinical characteristics and outcomes of patients with TMP-SXT-susceptible (TSSSM) and TMP-SXT-resistant S. maltophilia (TSRSM) monomicrobial bacteremia.nnnMETHODSnThe medical records of adult patients with TSSSM and TSRSM monomicrobial bacteremia from January 2004 to December 2013 were reviewed and classified into two groups, namely, TSSSM and TSRSM.nnnRESULTSnThere were 184 patients with monomicrobial S. maltophilia bacteremia. The mean age was 68.3 years. Most patients were males (72.8%), had high Charlson Comorbidity Index scores, previously prescribed antimicrobial agents, and indwelling medical devices. The 14-day and in-hospital mortality rates were 23.9% and 47.2%, respectively. There were 128 patients (69.6%) with TSSSM and 56 (30.4%) with TSRSM. The incidence of TSSSM bacteremia increased during the study period. The TSSSM and TSRSM groups had similar demographic and clinical characteristics and no significant differences in 14-day and in-hospital mortality (24.2% vs. 23.2%, pxa0=xa00.833; 50.0% vs. 41.1%, pxa0=xa00.264, respectively). Patients with TSSSM bacteremia had an increased risk of septic shock (pxa0=xa00.044) and neutropenia (pxa0=xa00.028) at bacteremia onset. Logistic regression analysis indicated that acquisition of TMP-SXT resistance was an independent risk factor for prolonged hospitalization (pxa0=xa00.018) and catheter-related S. maltophilia bacteremia was inversely associated with prolonged hospitalization after bacteremia (pxa0=xa00.032).nnnCONCLUSIONnThere were no significant differences in mortality for patients with TSSSM and TSRSM bacteremia, but patients with TSRSM bacteremia were associated with prolonged hospitalization after bacteremia onset.

Clinical manifestations and prognostic factors of Morganella morganii bacteremia.

Although Morganella morganii causes a variety of clinical infections, there are limited studies on M. morganii bacteremia after the year 2000. A total of 109 patients with M. morganii bacteremia at a medical center in Taiwan from 2003 to 2012 were studied. Among them, 30.3xa0% had polymicrobial bacteremia and 75.2xa0% had community-acquired infection. The most common underlying diseases were hypertension (62.4xa0%) and diabetes mellitus (38.5xa0%). The urinary tract (41.3xa0%) was the major portal of entry, followed by the hepatobiliary tract (27.5xa0%), skin and soft tissue (21.1xa0%), and primary bacteremia (10.1xa0%). Susceptibility testing of M. morganii isolates showed ubiquitous resistance to first-generation cephalosporins and ampicillin–clavulanate; resistance rates to gentamicin, piperacillin–tazobactam, and ciprofloxacin were 30.3xa0%, 1.8xa0%, and 10.1xa0%, respectively. Overall, the 14-day mortality was 14.7xa0%. Univariate analysis revealed that elevated blood urea nitrogen (BUN) values [pu2009=u20090.0137, odds ratio (OR) 5.26], intensive care unit (ICU) admission (pu2009=u20090.011, OR 4.4), and higher Acute Physiology and Chronic Health Evaluation II (APACHE II) scores (pu2009<u20090.001, OR 1.62) were significantly associated with mortality. The APACHE II score remained the only significant risk factor for mortality in multivariate analysis (pu2009=u20090.0012, OR 1.55). In conclusion, M. morganii bacteremia patients were mostly elderly, with one or more comorbidities. Most of the patients had community-acquired infection via the urinary and hepatobiliary tracts. Furthermore, prognosis can be predicted according to disease severity measured by the APACHE II score.

AdeRS combination codes differentiate the response to efflux pump inhibitors in tigecycline-resistant isolates of extensively drug-resistant Acinetobacter baumannii.

Tigecycline (TGC)-resistant extensively drug-resistant Acinetobacter baumannii (XDRAB) is an increasing threat in regard to nosocomial infections. The resistance–nodulation–cell division (RND) efflux pump has played an important role in TGC resistance. In this study, total 81 TGC-resistant XDRAB isolates were analyzed for their responses to the efflux pump inhibitor 1-(1-naphthylmethyl)-piperazine (NMP). We found that NMP could reduce by 4-fold or greater than 4-fold the minimum inhibitory concentration (MIC) of TGC in 45 isolates (55.6xa0%). After typing with pulsed-field gel electrophoresis (PFGE), group A appeared to be the major cluster with good synergistic response to NMP. Transcripts of the AdeABC efflux pump gene were consistently more correlated with TGC resistance than transcripts of the AdeFGJ or AdeIJK efflux pump genes in these isolates. Of the 81 isolates, the amino acid sequences of AdeR and AdeS were further classified and combined into 31 different codes. Although the dissemination of TGC-resistant XDRAB isolates was genetically diverse in our hospital, their responses to NMP conversion were still strain-dependent. We found that AdeRS combination codes were better than PFGE typing in separating groups of isolates with different sensitivity to NMP conversion.