Chun-Hsiang Chiu

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

BACKGROUND/PURPOSE The 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. METHODS Of 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. RESULTS The 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). CONCLUSION Male 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.

A Ruptured Cerebral Mycotic Aneurysm Caused By Abiotrophia defectiva Endocarditis

We describe a case of ruptured cerebral mycotic aneurysm caused by Abiotrophia defectiva endocarditis in a previously healthy man. The patient underwent craniotomy with clipping of aneurysm and received antibiotic treatment for 6 weeks and survived.

Risk factors and outcomes of cytomegalovirus viremia in cancer patients: a study from a medical center in northern Taiwan.

BACKGROUND Cytomegalovirus (CMV) is a pathogen and can cause life-threatening infection in the patients with malignancies. This study was conducted to investigate the risk factors and outcomes of CMV viremia in patients with malignancies. METHODS Data were collected with retrospective analysis from adults suffering from CMV viremia with underlying malignancies. A total of 107 patients were enrolled in a tertiary medical center in northern Taiwan from March 2008 to December 2009. RESULTS Among the 107 patients who suffered with CMV viremia with an overall mortality rate of 56.1% (60/107), 75 patients (70.1%) had solid organ malignancies and 32 (29.9%) had hematological malignancies. Mechanical ventilation (p=0.048), leukocytosis (p=0.004), and lack of appropriate early treatment (p=0.011) were independent predisposing factors associated with higher mortality rate. CONCLUSIONS CMV viremia predicts high mortality rate in cancer patients, especially in those with mechanical ventilation, leukocytosis, and lack of appropriate early treatment. Appropriate early antiviral therapy is recommended to improve outcomes.

Impact of age on neutrophil phagocytic reaction with different capsular serotypes of Klebsiella pneumoniae

BACKGROUND Although the prevalence of K pneumoniae liver abscess is higher in patients older than 55 years, the possible relationship of age with decreased phagocytic function of the patients with Klebsiella pneumoniae liver abscess has not been investigated. Our aim was to determine whether susceptibility to K pneumoniae infection depended on age-related impairment of phagocytic function. METHODS The study enrolled 42 subjects in three age groups: younger than 40 years (n=10), 40-65 years (n=12), and older than 65 years (n=20). Seventy-five strains of K pneumoniae were investigated, including liver abscess isolates (n=25) and blood isolates from the patients without liver abscesses (n=50). The rate of phagocytosis of K1/K2 (n=36) and non-K1/K2 (n=39) K pneumoniae by neutrophils was determined using flow cytometry and compared among the three age groups. RESULTS The rate of phagocytosis of serotype K1/K2 isolates was significantly lower in the middle-aged group than that in the younger group (p=0.015) and significantly lower in the older group than those in the middle-aged and younger groups (p=0.025 and p<0.01). In contrast, the rate of phagocytosis of non-K1/K2 isolates was similar in all three age groups at 60 minutes (66.4±1.85%, 65.2±2.0%, and 62.3±1.81%; p=not significant). CONCLUSIONS Thus, as age increases, the ability of neutrophils to phagocytose virulent K1/K2 K pneumoniae decreases. This finding may account for the higher prevalence of K pneumoniae liver abscesses in older patients.

Comparison of the effectiveness and antibiotic cost among ceftriaxone, ertapenem, and levofloxacin in treatment of community-acquired complicated urinary tract infections

PURPOSE To study characteristics of patients with community-acquired complicated urinary tract infections (cUTIs) and to compare effectiveness and antibiotic cost of treatment with ceftriaxone (CRO), levofloxacin (LVX), and ertapenem (ETP). METHODS This retrospective study enrolled patients who had community-acquired cUTIs admitted to Division of Infectious Diseases in a single medical center from January 2011 to March 2013. Effectiveness, antibiotic cost, and clinical characteristics were compared among patients treated with CRO, LVX, and ETP. RESULTS There were 358 eligible cases, including 139 who received CRO, 128 treated with ETP, and 91 with LVX. The most common pathogen was Escherichia coli. The susceptibilities of these three agents were higher and more superior than first-line antibiotics. Treatment with ETP was associated with a significantly shorter time to defervescence since admission (CRO: 39 hours, ETP: 30 hours, and LVX: 38 h; p = 0.031) and shorter hospitalization stay (CRO: 4 days, ETP: 3 days, and LVX: 4 days; p < 0.001). However, the average antibiotic costs in the CRO group were significantly lower than that in the other two groups [CRO: 62.4 United States dollars (USD), ETP: 185.33 USD, and LVX: 204.85 USD; p < 0.001]. CONCLUSION The resistance of cUTIs isolates to first-line antibiotic is high. Using ETP, CRO, and LVX in the treatment of cUTIs for good clinical response should be suggested. Among the three agents, ETP had better susceptibility than CRO and LVX, reached defervescence sooner, and was associated with shorter hospital stays. However, using CRO in cUTIs was less expensive than the other two agents.

Molecular epidemiology of carbapenem non-susceptible Acinetobacter nosocomialis in a medical center in Taiwan

The mechanism by which carbapenem non-susceptible Acinetobacter nosocomialis (CNSAN) is disseminated is rarely described in the literature. In this study, we delineated the molecular epidemiology of CNSAN isolated from patients in a medical center in Taiwan. Fifty-four non-duplicate bloodstream isolates of CNSAN were collected at the Taipei Veterans General Hospital between 2001 and 2007. Pulsed-field gel electrophoresis (PFGE) was performed to determine their clonal relationship. Carbapenem-resistance genes and associated genetic structures were detected by polymerase chain reaction (PCR) mapping. Southern hybridization was performed to determine the plasmid location of carbapenem-resistance genes. Transmissibility of these genes to Acinetobacterbaumannii was demonstrated by conjugation tests. The overall carbapenem non-susceptibility rate among A. nosocomialis isolates during the study period was 21.6% (54/250). PFGE revealed three major pulsotypes: H (n=23), I (n=10), and K (n=8). The most common carbapenem-resistance gene was blaOXA-58 (43/54, 79.6%), containing an upstream insertion sequence IS1006 and a truncated ISAba3 (IS1006-ΔISAba3-like-blaOXA-58). All isolates belonging to the pulsotypes H, I, and K carried plasmid located IS1006-ΔISAba3-like-blaOXA-58. A common plasmid carrying ISAba1-blaOXA-82 was found in six isolates, which belonged to five pulsotypes. A type 1 integron that carried blaIMP-1 was detected in different plasmids of seven isolates, which belonged to five pulsotypes. Plasmids carrying these carbapenem-resistant determinants were transmissible from A. nosocomialis to A. baumannii via conjugation. In this medical center, CNSAN mainly emerged through clonal dissemination; propagation of plasmids and integrons carrying carbapenem-resistant determinants played a minor role. This study showed that plasmids carrying carbapenem-resistant determinants are transmissible from A. nosocomialis to A. baumannii.

Endogenous Endophthalmitis Caused by Citrobacter koseri

Endogenous endophthalmitis occurs when organisms are hematogenously disseminated in to the eye from a distant focus of infection. The most common isolated organisms that cause endogenous endophthalmitis are Klebsiella pneumoniae and Escherichia coli. Previous reports on endophthalmitis caused by Citrobacter species are limited. We present the first case of endogenous endophthalmitis caused by Citrobacter koseri bacteremia and renal abscesses.

Leptospirosis after Typhoon in Taiwan

Background: Leptospirosis, an infectious disease that affects humans and animals, is a common zoonosis with a variety of clinical manifestations. Taiwan is one of the countries with a high incidence of leptospirosis. It is important to recognize the clinical features and risk factors of this disease. The aim of this study is to analyze the characteristics of patients with leptospirosis and correlate the onset of symptoms with exposure to a typhoon. Methods: We report 6 cases of serologically confirmed leptospirosis who required hospitalization during the past 5 years. The clinical characteristics, history of exposure to contaminated water and soil, and association with the occurrence of a typhoon were reviewed. Results: All patients were found to have a history of contact with contaminated soil or water. Five of these patients (83%) suffered from the disease just after a typhoon. Fever was the most common symptom in all cases (100%), followed by chills (83%) and myalgia (67%). Acute renal failure was the most common complication in these cases (83%), followed by jaundice (67%), acute respiratory failure (50%), and disseminated intravascular coagulation (33%). Jarisch-Herxheimer reactions were seen in three cases (50%). All cases were successfully treated with antimicrobial agents. Conclusion: Most (83%) patients suffered from leptospirosis after a typhoon. In order to prevent leptospirosis in Taiwan, it is important to educate the people on avoiding contact with contaminated water, moist soil, vegetation, and wearing protective clothing and footwear in areas suspected to be contaminated during the typhoon season. Educating the physicians on the early diagnosis of leptospirosis is also crucial in Taiwan.

Individual or combined effects of meropenem, imipenem, sulbactam, colistin, and tigecycline on biofilm-embedded Acinetobacter baumannii and biofilm architecture

ABSTRACT Acinetobacter baumannii biofilms are difficult to eradicate. We investigated the effects of meropenem (2 mg/liter), imipenem (2 mg/liter), sulbactam (4 mg/liter), colistin (2 mg/liter), and tigecycline (2 mg/liter), alone or in combination, on biofilm-embedded carbapenem-resistant and carbapenem-susceptible A. baumannii (CRAb and CSAb, respectively) cells, as well as on the architecture of the biofilms. A. baumannii ATCC 15151 (Ab15151) and its OXA-82-overproducing transformant, along with two clinical CSAb and two clinical CRAb isolates of differing clonalities, were used. The minimal bactericidal concentrations for biofilm-embedded cells of the six tested isolates were >50-fold those of their planktonic cells. When used individually, meropenem exhibited a higher killing effect than the other four antimicrobials on biofilm-embedded CSAb cells in the colony biofilm assay. For two clinical CRAb isolates, meropenem plus sulbactam or sulbactam plus tigecycline showed >100-fold the bactericidal effect exhibited by these agents used alone after 48 h of treatment. The effect of antimicrobials on the architecture of Ab15151 biofilm emitting green fluorescence was determined by confocal laser scanning microscopy using COMSTAT software. Significant decreases in the maximum biofilm thickness were observed after exposure to meropenem and imipenem. Meropenem plus sulbactam significantly decreased the biomass and mean thickness and increased the roughness coefficient of biofilms, but sulbactam plus tigecycline only decreased the maximum and mean biofilm thickness compared to any of these agents used alone. Meropenem was active against biofilm-embedded CSAb, whereas meropenem plus sulbactam exhibited synergism against biofilm-embedded CRAb and caused significantly more damage to the biofilm architecture than did any of the agents used alone.

Risk of mortality of Catheter-Related Bloodstream Infections caused by acinetobacter species: Is early removal of the catheters associated with a better survival outcome?

Purpose: Bloodstream infections (BSIs) caused by Acinetobacter species have been extensively reported, however, which majorly focused on respiratory tract infections. The risk of mortality and the effect of early catheter removal on survival in catheter-related BSIs (CRBSIs) caused by Acinetobacter spp. remain unclear. This study aims to investigate that. Methods: This is a retrospective multicentric study conducted in Taiwan from 2012 to 2014. Patients with at least 1 positive blood culture and catheter culture for the same Acinetobacter spp., showing symptoms and signs of CRBSIs, were included (n = 119). Risk factors for 30-day mortality were analyzed using a logistic regression model. The characteristics of patients with early catheter removal (within 48 hours after CRBSIs) were compared to those without removal matching for age, sex, and disease severity. Results: There were no differences in 30-day mortality with regard to causative Acinetobacter spp., catheter type, site, and appropriateness of antimicrobial therapy. Patients with higher Acute Physiologic and Chronic Health Evaluation (APACHE) II scores (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.02-1.23; P = .014), shock (OR: 6.43; 95% CI: 1.28-32.33; P = .024), and longer hospitalization before CRBSIs (OR: 1.04; 95% CI: 1.00-1.08; P = .027) had a significantly higher 30-day mortality rate. Early removal of catheters after CRBSIs was not associated with better survival benefits. Conclusion: Higher disease severity (APACHE II score), shock, and longer hospitalization before bacteremia were independently associated with a higher 30-day mortality in CRBSIs caused by Acinetobacter spp. In previous published guidelines, infected catheters were suggested to be removed in CRBSIs caused by gram-negative bacilli. Even though early removal of catheters did not associate with a better survival outcome in current results, it should be judiciously evaluated according to the clinical conditions and risks individually. For better elucidation of these issues, further well-controlled prospective study may be warranted.