Analysis of Immune Response In Bacterial Infection of Obese Subject

Inclusion Criteria: * between18 and 80 years * obesity: BMI \> 30 * presumed bacterial infection: * pneumonitis (documented or probably) * pyelonephritis / acute prostatitis * soft tissue / skin infection (except for bedsore) * cholecystitis / angiocholitis * meningitis * clostridium colitis * surgical site infection * signed consent Exclusion Criteria: * patients with viral, parasitic or mycotic documented infection * patients with bacterial infection with treatment\> 4 weeks (ex. endocarditis; osteo- articular infections) * patients with prior antibiotic treatment (\< 14 days) * intensive care unit patients * patients with a history of cancer or malignant hematological disease within the 5 previous years that is currently clinically significant (non metastatic prostatic and basocellular malignancy are excluded) * patients with systemic disease * Known diagnosis of human immunodeficiency infection (DICV, HIV…) * immunosuppression treatment during last month including corticotherapy * pregnancy * 3 months follow up not possible * non signed consent