Pseudomonas aeruginosa is a pathogenic bacteria for human, especially in hospital settings. It can sometimes be multi-resistant to many or even to all antibiotics usually used for its treatment.

The aim of the study is to isolate and produce therapeutic antibodies against the bacteria Pseudomonas aeruginosa in order to provide an alternative treatment to antibiotics in case of infection with an antibiotic-resistant strain of Pseudomonas aeruginosa.

Inclusion Criteria:

• Patient selected in the retrospective part of the study (patient with serum containing functional anti-Pseudomonas aeruginosa antibodies)
• Patient with weight ≥ 32kg.
• With a follow-up visit at Grenoble University Hospital with a blood sampling for its care
• Having given its written no objection to participate in the prospective phase of this project

Exclusion Criteria:

• Legally protected patient (minor, pregnant or nursing woman, ward or ward curated, hospitalized under duress or deprived of liberty)

Patient previously infected or colonized by Pseudomonas aeruginosa with serum containing functional anti-Pseudomonas aeruginosa antibodies