Pharmacokinetics of High-dose Ceftobiprole in Community-acquired Pneumonia Under Mechanical Ventilation.

Inclusion Criteria: * All patients (or his/her representative for those patients who are unable to express their consent) who have given free, informed consent, and signed the consent form. * All patients affiliated to or benefitting from a health insurance scheme. * All patients hospitalised in the intensive care unit with severe acute community-acquired pneumonia requiring the use of mechanical ventilation: this is characterised by signs and symptoms corresponding to an infection of the lower respiratory tract and imaging data corresponding to bacterial pneumonia.The patient has been under mechanical ventilation for less than 24 hours. Exclusion Criteria: * Any patient who is already taking part in another interventional study that may influence the main criterion for judgement. * Any patient who is in the exclusion period determined by another study. * Any patient under curatorship or guardianship established by a court * Any patient who is pregnant, about to give birth or breastfeeding. * Any patient with a contra-indication or allergy to beta-lactams * Any patient whose survival is estimated at less than 48 hours * Any patient whose discharge from hospital is planned for 24 hours after admission * Any patient whose creatinine clearance is estimated at less than 50 ml/min or who is undergoing renal replacement therapy * Any patient undergoing extracorporeal life support.