title: Serological hint suggesting that Parachlamydiaceae are agents of pneumonia in polytraumatized intensive care patients.
abstract: Parachlamydiaceae are potential emerging pathogens that naturally infect free-living amoebae. Intensive-care patients are highly exposed to aerosols and, consequently, exposed to free-living amoebae and to their intracellular hosts. Thus, we tested intensive-care patients for antibodies to Parachlamydia and determined if serum reactivity was associated with pneumonia. Patients who underwent intubation and were hospitalized in our intensive-care unit were eligible. Clinical data and serum were recorded prospectively. Seventy-three sera taken from 37 intensive-care patients and 100 sera from healthy blood donors were tested for reactivity against Parachlamydia by immunofluorescence. We detected an antibody titer greater than or equal to 1:100 in 5 out of 37 intensive-care unit patients (13.5%), including three seroconversions (8.1%). By contrast, no blood donors were reactive against Parachlamydia (P < 0.001). All patients with serological evidence of a recent exposure to Parachlamydia were trauma patients with head injury and aspiration pneumonia. Moreover, both patients with serological evidence of previous exposure to Parachlamydia were admitted for a cerebral hemorrhage. This serological study suggests that Parachlamydiaceae are associated with aspiration pneumonia in trauma patients admitted to intensive-care units.
authors.affiliation: Unité des Rickettsies, Faculté de médecine, and Département d'anesthésie réanimation, Hôpital Nord, Marseille, France. gilbert.greub@medecine.univ-mrs.fr
authors.forename: Gilbert
authors.initials: G
authors.lastname: Greub
authors.forename: Ioanna
authors.initials: I
authors.lastname: Boyadjiev
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Claude
authors.initials: C
authors.lastname: Martin
mesh_terms: D000059:Accidents; D000942:Antigens, Bacterial / Q000302:isolation & purification; D002695:Chlamydiales / Q000145:classification* / Q000302:isolation & purification; D003422:Critical Care; D005334:Fever; D005455:Fluorescent Antibody Technique; D005602:France; D006801:Humans; D007362:Intensive Care Units; D018410:Pneumonia, Bacterial / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014947:Wounds and Injuries
chemical_list: D000942:Antigens, Bacterial