A prospective multicentre study of the epidemiology and outcomes of bloodstream infection in cirrhotic patients.

OBJECTIVES: To describe the current epidemiology of bloodstream infection (BSI) in patients with cirrhosis; and to analyse predictors of 30-day mortality and risk factors for antibiotic resistance. METHODS: Cirrhotic patients developing a BSI episode were prospectively included at 19 centres in five countries from September 2014 to December 2015. The discrimination of mortality risk scores for 30-day mortality were compared by area under the receiver operator risk and Cox regression models. Risk factors for multidrug-resistant organisms (MDRO) were assessed with a logistic regression model. RESULTS: We enrolled 312 patients. Gram-negative bacteria, Gram-positive bacteria and Candida spp. were the cause of BSI episodes in 53%, 47% and 7% of cases, respectively. The 30-day mortality rate was 25% and was best predicted by the Sequential Organ Failure Assessment (SOFA) and Chronic Liver Failure-SOFA (CLIF-SOFA) score. In a Cox regression model, delayed (>24 hours) antibiotic treatment (hazard ratio (HR) 7.58; 95% confidence interval (CI) 3.29-18.67; p < 0.001), inadequate empirical therapy (HR 3.14; 95% CI 1.93-5.12; p < 0.001) and CLIF-SOFA score (HR 1.35; 95% CI 1.28-1.43; p < 0.001) were independently associated with 30-day mortality. Independent risk factors for MDRO (31% of BSIs) were previous antimicrobial exposure (odds ratio (OR) 2.91; 95% CI 1.73-4.88; p < 0.001) and previous invasive procedures (OR 2.51; 95% CI 1.48-4.24; p 0.001), whereas spontaneous bacterial peritonitis as BSI source was associated with a lower odds of MDRO (OR 0.30; 95% CI 0.12-0.73; p 0.008). CONCLUSIONS: MDRO account for nearly one-third of BSI in cirrhotic patients, often resulting in delayed or inadequate empirical antimicrobial therapy and increased mortality rates. Our data suggest that improved prevention and treatment strategies for MDRO are urgently needed in the liver cirrhosis patients.

Determination of biofilm production by Candida tropicalis isolated from hospitalized patients and its relation to cellular surface hydrophobicity, plastic adherence and filamentation ability.

Candida tropicalis is an emerging virulent species. The aim of this study is to determine the biofilm-forming ability of 29 strains of C. tropicalis isolated from inpatients, and to examine its relation with other virulence factors such as cellular surface hydrophobicity (CSH), immediate (15 min, IA) and late (24 h, LA) plastic adherence and filamentation ability. The study was performed in parallel using two incubation temperatures - 37 and 22 °C - to determine the effect of growth temperature variations on these pathogenic attributes of C. tropicalis. Biofilm formation (BF) was measured by optical density (OD) and by XTT reduction (XTT); Slime index (SI), which includes growth as a correction factor in BF, was calculated in both methods. All strains were hydrophobic and adherent - at 15 min and 24 h - at both temperatures, with higher values for 22 °C; the adhered basal yeast layer appears to be necessary to achieve subsequent development of biofilm. Filamentation ability varied from 76.2% of strains at 37 °C to 26.6% at 22 °C. All C. tropicalis strains were biofilm producers, with similar results obtained using OD determination and XTT measurement to evaluation methods; SI is useful when good growth is not presented. BF at 37 °C was similar at 24 h and 96 h incubation; conversely, at 22 °C, the highest number of biofilm-producing strains was detected at 96 h. CSH is an important pathogenic factor which is involved in adherence, is influenced by the filamentation of yeast, and plays a critical role in BF.

Aspartyl proteinase, phospholipase, hemolytic activities and biofilm production of Candida albicans isolated from bronchial aspirates of ICU patients.

A correlation between mucosal colonization by Candida albicans and the subsequent development of invasive respiratory infection has been previously described. The aim of this study was to evaluate different enzymatic activities in vitro and to determine the capacity to form biofilms by 17 C. albicans isolates from bronchial aspirates of mechanically ventilated patients hospitalized in intensive care units. All the C. albicans clinical isolates tested were biofilm producers and displayed detectable levels of proteinase and hemolytic activities, although phospholipase activity was not detected in one strain. The correlation noted among the virulence factors studied suggests that the presence of more than one concurrent factor could facilitate the spread of infection.

Enzymatic activities of Candida tropicalis isolated from hospitalized patients.

Secretion of hydrolytic enzymes is considered a virulence factor in Candida spp. Extracellular enzymatic activities in 29 clinical isolates of Candida tropicalis were analyzed by plate assays. C. tropicalis, similar to Candida albicans, showed elevated hemolytic and esterase activities. However, unlike C. albicans, low aspartyl protease and very low phospholipase activities were detected in C. tropicalis isolates.