Epidemiology and prognostic determinants of bacteraemic biliary tract infection.

OBJECTIVES: To determine the epidemiology of bacteraemia due to biliary tract infection (BTI) and to identify independent predictors of mortality. METHODS: This study was part of a bloodstream infection surveillance study that prospectively collected data on consecutive patients with bacteraemia in our institution from 1991 to 2010. BTI was the confirmed source of 1373 patients with bacteraemia, and the independent prognostic factors of 30 day mortality were determined. RESULTS: The mean age of patients with biliary sepsis was 71 years (± 14 years). The most frequent comorbidities were biliary lithiasis and solid-organ cancer [484 cases (35%) and 362 cases (26%), respectively]. The BTI was healthcare-associated in 33% of patients. Shock and mortality accounted for 209 and 126 cases, respectively (15% and 9%). The most frequent microorganisms isolated were Escherichia coli (749, 55%), Klebsiella spp. (240, 17%), Enterococcus spp. (171, 12%), Pseudomonas aeruginosa (86, 6%) and Enterobacter spp. (63, 5%). There were 47 (3%) cefotaxime-resistant (CTX-R) E. coli or Klebsiella spp. Inappropriate empirical antibiotic treatment was an independent factor associated with mortality (OR 1.4, 95% CI 1.1-1.7). Inappropriate empirical treatment was more frequent in P. aeruginosa and CTX-R Enterobacteriaceae bacteraemia. These microorganisms were significantly more common in patients with previous antibiotic therapy, solid-organ cancer or transplantation and in healthcare-associated bacteraemia. CONCLUSIONS: In patients with bacteraemic BTI, inappropriate empirical therapy was more frequent in P. aeruginosa and CTX-R Enterobacteriaceae infection and was associated with a higher mortality rate. In patients with bacteraemia due to BTI and solid-organ cancer or transplantation, healthcare-associated infection or previous antibiotic treatment, initial therapy with piperacillin/tazobactam or a carbapenem would be advisable.

Candida species bloodstream infection: epidemiology and outcome in a single institution from 1991 to 2008.

Candidaemia remains a major cause of morbidity and mortality in the healthcare setting. Candida spp. bloodstream infection episodes prospectively recorded through a blood culture surveillance programme in a single institution from 1991 to 2008 were included in the study. Data regarding candidaemia episodes were analysed, including specific fungal species and patient survival at 30 days after diagnosis. There were 529 candidaemia episodes during the study period (495 were nosocomial infections). The incidence of candidaemia caused by non-Candida albicans Candida spp. (52%) was higher than the incidence of candidaemia caused by C. albicans (48%). The overall crude 30 day mortality rate was 32%. Patients with Candida parapsilosis candidaemia had the lowest mortality rate (23%). Candida krusei candidaemia was most commonly associated with haematological malignancy (61%; P < 0.001), stem cell transplantation (22%; P = 0.004), neutropenia (57%; P = 0.001) and prior use of antifungal azole agents (26%; P < 0.001). Patients with C. krusei candidaemia had the highest crude 30 day mortality in this series (39%). Epidemiological studies are important to define clinical and microbiological candidaemia characteristics and to guide empirical treatment in every setting.

[Epidemiology and clinical presentation of Panton-Valentin leukocidin positive methicillin-resistant Staphylococcus aureus]. / Epidemiología y forma de presentación clínica de las infecciones originadas por Staphylococcus aureus resistente a meticilina productor de leucocidina de Panton-Valentine.

INTRODUCTION: the aim of our study was to review the epidemiology and clinical manifestations of infections due to Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (PVL-MRSA). MATERIAL AND METHODS: Medical history of patients infected by MRSA-PVL admitted to our hospital from January 2007 to July 2009 was reviewed. PVL and the type of cromosomic cassette were determined in all strains by PCR. RESULTS: A total of 37 cases were included. Seventy percent were males and the median age was 39 years. Sixtytwo percent were Spanish, 14 (37.8%) were HIV-positive and 11 (29.7%) were homosexual. The source of the infection was the skin and soft tissue in 36 cases and pneumonia in 1. Sixteen patients were hospitalized, 5 had bacteremia and 5 developed septic metastasis. The relapse rate was 24% (9 cases). The prevalence during the study period was 11.2% of all MRSA isolated (37 out of 329). All the strains had a cromosomic cassette type IV and were susceptible to cotrimoxazole, rifampin, vancomyin, daptomycin and linezolid. The MIC of vancomycin, measured by E-test, was ≥ 1.5 mg/L in 28 out of 34 cases (82.3%). CONCLUSIONS: Eleven percent of the MRSA strains isolated in our hospital are PVL positive. In general, skin and soft tissue infections are the most common and bacteremia or septic metastasis are frequent. In contrast to previous Spanish studies, more cases are observed in patients born in Spain and the infections are more severe.

Antibiotic resistance in orthopaedic surgery: acute knee prosthetic joint infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.

The aim of this study was to describe the prevalence and characteristics of knee prosthetic joint infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. From 2000 to 2007, 132 infections out of 5,076 arthroplasties (2.6%) were registered. Seven out of 132 infections (5.3%) were due to ESBL-producing Enterobacteriaceae, Escherichia coli in six cases and Klebsiella pneumoniae in one. Open debridement and retention of the implant was the first surgical approach and all patients received intravenous carbapenems. Relapse was documented in four cases and remission in three. Therefore, debridement without prosthesis removal was associated with a high failure rate.

[Surveillance of commensal flora evolution and infections in neutropenic cancer patients submitted to chemoprophylaxis]. / Vigilancia de la evolución de la flora comensal y de las infecciones en pacientes oncológicos con neutropenia sometidos a quimioprofilaxis.

The evolution of the flora and its resistance to different antimicrobials in neutropenic patients submitted to high-dose chemotherapy with autologous blood stem-cell transplantation, and the relation of these findings to the etiology of the infections the patients developed was studied in order to evaluate the suitability of the chemoprophylaxis and the empirical antibiotic therapy used. Forty-one patients were analyzed in a period of 28 months. The chemoprophylaxis used was levofloxacin, fluconazole and acyclovir. The empirical sequential treatment was an initial administration of cefepime, followed by teicoplanin and amikacin. Cultures were done of nasal and pharyngeal smears, Hickman catheter and stools, 1 day before chemoprophylaxis started and then on days 5 and 9. In the case of fever, three sets of blood cultures and urine cultures were done and samples from areas related to the clinical condition were analyzed. Levofloxacin induced the selection of resistant strains or species in the flora and in the infectious agents. Fluconazole also selected resistant species in the flora. Seventeen infections were documented in eleven patients, produced by Gram-positive bacteria in thirteen cases (81.25%) and by Gram-negative bacteria in three (18.75%). The coagulase negative staphylococci and Enterococcus faecalis were the most frequent agents of infection. We identified on nine occasions the same microorganism in the flora and in the pathological product; this suggests its endogenous origin and supports the use of prospective cultures of the flora, monitoring the sensibility of the microorganisms isolated to the antimicrobials used in chemoprophylaxis and empirical treatment.