The role of Enterococcus spp. and multidrug-resistant bacteria causing pyogenic liver abscesses.

BACKGROUND: Pyogenic liver abscesses (PLA) remain a significant clinical problem. Unfortunately, little is known about current bacterial susceptibility profiles and the incidence of multidrug resistant organisms (MDROs) causing PLA in Western countries. Yet, this crucial information is pivotal to guide empirical antibiotic therapy. Aim of this study was to provide detailed characteristics of PLA with a special focus on underlying bacterial pathogens and their susceptibility to antibiotics. METHODS: A retrospective study of patients diagnosed with PLA from 2009 to 2015 in a large tertiary reference center in Germany was performed in order to characterize PLA and antimicrobial susceptibility profiles of causative bacterial species. RESULTS: Overall, 86 patients were included. The most common causes of PLA were bile duct stenosis/obstruction (31.4%) and leakage of biliary anastomosis (15.1%). Frequent predisposing diseases were malignancies (34.9%), diabetes (24.4%) and the presence of liver cirrhosis (16.3%). Of note, Enterococcus spp. were the most frequently cultured bacterial isolates (28.9%), and in 1/3 of cases vancomycin resistance was observed. In addition, a relevant frequency of gram-negative MDROs was identified. In particular, an alarming 10% and 20% of gram-negative bacteria were resistant to carbapenems and tigecycline, respectively. Of note, MDRO status did not predict ICU stay or survival in multivariate regression analysis. The mortality rate in our series was 16.3%. CONCLUSION: Our study demonstrates an as yet underreported role of Enterococcus spp., often associated with vancomycin resistance, as well as of gram-negative MDROs causing PLA.

A one-year follow-up study on the incidence and risk of endophthalmitis after pyogenic liver abscess.

PURPOSE: Although endophthalmitis secondary to pyogenic liver abscess (PLA) is becoming a globally emerging infectious disease, population-based investigations evaluating the relationship between PLA and endogenous endophthalmitis remain scarce. This study aimed to investigate the incidence and risk of endogenous endophthalmitis in patients with PLA compared with unaffected individuals by using a nationwide, population-based dataset. DESIGN: Retrospective, cohort study. PARTICIPANTS AND CONTROLS: This study used data sourced from Taiwan's National Health Insurance Research Database. In total, 12 727 patients with PLA were included in the study group and 63 635 matched subjects were randomly extracted as a comparison group. METHODS: Stratified Cox proportional hazards regressions were performed to assess the effect of PLA on the hazard of developing endogenous endophthalmitis. MAIN OUTCOME MEASURES: The incidence and risk of endogenous endophthalmitis between the study group and comparison group. RESULTS: Of the total sample, 148 subjects (0.10%) were diagnosed with endophthalmitis during the 1-year follow-up period. Endophthalmitis was found in 106 patients (0.84%) with PLA and 42 comparison patients (0.07%). After adjusting for patient monthly income, geographic location, and urbanization level, those suffering from PLA were found to have a greater likelihood of developing endophthalmitis during the 1-year follow-up period than comparison patients (hazard ratio [HR], 12.83; 95% confidence interval, 8.94-18.41). Stratification did not reveal any large differences in the adjusted HRs for endophthalmitis between PLA patients suffering from diabetes and those in whom diabetes was absent. We further analyzed the etiology of cases with endogenous endophthalmitis in this investigation and found Klebsiella pneumonia to be the causative organism among 75.5% of the cases but only 33.4% of the comparison group. CONCLUSIONS: We found that the incidence and risk of developing endophthalmitis was significantly higher among patients with PLA compared with matched controls irrespective of diabetes status.

Early diagnosis and therapeutic choice of Klebsiella pneumoniae liver abscess.

Nowadays, pyogenic liver abscess (PLA) is still a common and severe intra-abdominal infection, and Klebsiella pneumoniae had emerged as the most common pathogenic bacteria worldwide in the past ten years. Our study aims to achieve an early pathogenic diagnosis and rational therapy modality for Klebsiella pneumoniae liver abscess (KLA) through clinical data analysis. A total of 197 inpatients in Zhongshan Hospital, Shanghai, diagnosed as having liver abscess between March 2001 and September 2009 were enrolled. Patients with monomicrobial infection were divided into two groups: patients with K. pneumoniae liver abscess (KLA group, n=106) and those with non-Klebsiella pneumoniae liver abscess (NKLA group, n=56). A retrospective analysis was made between these two groups on the aspects of underlying diseases, clinical characteristics, laboratory data, culture results, and imaging findings. To evaluate the effects of different medical interventions, monomicrobial KLA patients were further divided into four subgroups (percutaneous liver aspiration, aspiration plus antibiotics flushing, aspiration plus retained catheter, and aspiration plus antibiotics flushing and retained catheter), and corresponding therapeutic effects were analyzed. KLA was more likely to occur in patients with coexisting diseases such as diabetes mellitus (53.77% vs 25.00%, P=0.001) and hepatic adipose infiltration (16.04% vs 5.36%, P=0.029). Compared to NKLA group, clinical characteristics including abdominal pain (40.57% vs 57.14%, P=0.044), hypodynamia (19.81% vs 46.43%, P=0.001), and hepatomegaly (4.72% vs 14.29%, P=0.033) were much milder, but with a higher fasting blood glucose level (7.84±0.36 vs 5.76±0.30, P=0.001) on admission in KLA group. In addition, KLA abscess often appeared singly in the right lobe of the liver with gas forming nature (32.88% vs 13.51%, P=0.039), unsmooth rim (71.23% vs 40.54%, P=0.002), and dynamic septum enhancement (41.10% vs 16.22%, P=0.009). Compared to mono aspiration subgroup, additional antibiotic flushing could not further improve clinical outcomes of KLA patients (P>0.05); however, the retained catheter showed obvious advantage in reducing abscess diameter (34.38±3.25 mm vs 22.67±2.37 mm, P=0.017). It can be concluded that the strong association with diabetes, milder clinical symptoms, and gas-forming nature in CT images makes early pathogenic diagnosis of KLA possible. Comparatively, ultrasonography-guided percutaneous liver aspiration with retained catheter may be the most rational intervention modality of KLA.

Chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin.

Chromobacterium violaceum infection is uncommon but potentially fatal, with a clinical picture similar to melioidosis but with different antibiotic sensitivities and treatment. This infection can involve any organ, but we believe this is the first reported case of C. violaceum endocarditis.