Relationship between pathogenic, clinical, and virulence factors of Staphylococcus aureus in infective endocarditis versus uncomplicated bacteremia: a case-control study.

Pathogenic factors of Staphylococcus aureus (SA) in the development of infective endocarditis (IE) have not been sufficiently investigated. The purpose of this study was to analyze the pathogenesis and virulence factors of SA in patients with IE as compared to patients with uncomplicated bacteremia (un-BAC). This is a retrospective case-control study (2002-2014) performed at a tertiary hospital in Spain. Clinical and epidemiological factors were analyzed. We assessed the presence of toxin genes [toxic shock syndrome toxin 1 (tst-1) and enterotoxins A (etA), B (etB), and D (etD)] and the potential relationship between accessory gene regulator (agr) groups and the development of IE confirmed by polymerase chain reaction (PCR). Twenty-nine patients with IE were compared with 58 patients with uncomplicated S. aureus bacteremia (SAB). As many as 75.9 % of patients had community-acquired IE (p < 0.005). Multivariate analysis revealed that there is a significant relationship between community-acquired infection and severe sepsis or septic shock and IE. Also, a minimum inhibitory concentration (MIC) of vancomycin ≥1.5 µg/ml was found to be associated with IE. The agr group I was prevalent (55.2 % vs. 31.0 %; p = 0.030). No association was observed between toxin genes (tst-1, etA, etB, and etD) and IE. The superantigen (SAg) most frequently found in SA isolates was tst-1 (12.6 %). We found no association between toxin genes and IE, probably due to the small sample size. However, a direct relationship was found between agr I and the development of IE, which suggests that agr I strains may have more potential to cause IE.

[Diagnostic and therapeutic assessment of liver trauma]. / Valoración diagnóstica y terapéutica de los traumatismos hepáticos.

We have observed an increase in the frequency of hepatic trauma. They are very severe (44% of our group in IV-V stage), right hepatic lobe is the most frequently injured (22 patients), are associated with several lesions and in 20% of patients radical proceedings (parenchymal resection) were needed. A high incidence of associated lesions (24 patients), mainly thoracic and cranio-encephalic, have been observed. Therefore we have to improve the vital support measures, both in the accident place and in their transport, as quick and safe as possible, to hospital. We have at present better diagnostic and management methods to evaluate these patients: abdominal puncture, echography and abdominal CT. The echography in emergencies is the examination of choice in severe abdominal trauma and laparatomy is an urgent procedure in uncertain cases. Most of the hepatic traumatisms were treated by conservative surgical procedures (suture, hemostasis and abdominal drainage in 25 patients), but at times hepatic resection was needed (6 patients). The main aim is this surgery is the hemorrhage control, which determines mortality and prompt reoperation. That happened in two cases. Respiratory problems, infection with sepsis, renal failure, biliary fistulas, upper digestive tract hemorrhages and hemobilia, are complications most frequently observed in our patients. The vital support measures (respiratory, cardiovascular, nutritional, neurologic, etc.) improve the clinical evolution. In our patients the mortality rate was 12%. This rate is very similar to the one reported by other authors.