title: Experimental Pseudomonas anguilliseptica infection in turbot Psetta maxima (L.): a histopathological and immunohistochemical study.
abstract: Experimental infection with Pseudomonas anguilliseptica was performed both by intraperitoneal (i.p.) and bath route on juvenile turbot (Psetta maxima) in order to evaluate the pathology induced. Turbot was found to be sensitive to i.p. challenge (1.7x10(6) CFU/fish) but no to bath exposure. The i.p. challenge induced septicaemic infection and mortality. Externally, moribund fish showed distended abdomen and pale areas at day 9. The gross pathological internal signs present were abundant ascitic fluid in the peritoneal cavity, pale and enlarged spleen, pale and friable liver, and congestive and dilated gut with yellowish exudates. On histopathological examination, bacterial invasion was common in all the tissues studied but the most prominent pathological changes were observed in gut, spleen and kidney after 7 day with features of necrosis. The immunohistochemical findings support the widespread localization of the bacteria after the i.p. injection since the P. anguilliseptica was detected in spleen from day 1 post injection, in liver, kidney and gut from day 4, in muscle from day 7 and in brain from day 9. The difficulties in infecting healthy fish by bath challenge can be explained by the opportunistic nature of this pathogen.
authors.affiliation: Dipartimento di Scienze Veterinarie, Facoltà di Medicina Veterinaria, Università di Camerino Matelica, (MC), Italy. gianenrico.magi@unicam.it
authors.forename: G E
authors.initials: GE
authors.lastname: Magi
authors.forename: S
authors.initials: S
authors.lastname: Lopez-Romalde
authors.forename: B
authors.initials: B
authors.lastname: Magariños
authors.forename: J
authors.initials: J
authors.lastname: Lamas
authors.forename: A E
authors.initials: AE
authors.lastname: Toranzo
authors.forename: J L
authors.initials: JL
authors.lastname: Romalde
mesh_terms: D000825:Animal Structures / Q000382:microbiology* / Q000473:pathology*; D000818:Animals; D001921:Brain / Q000382:microbiology / Q000473:pathology; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology* / Q000473:pathology*; D005412:Flatfishes / Q000276:immunology / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000382:microbiology / Q000473:pathology; D007150:Immunohistochemistry; D007668:Kidney / Q000382:microbiology / Q000473:pathology; D008099:Liver / Q000382:microbiology / Q000473:pathology; D009132:Muscles / Q000382:microbiology / Q000473:pathology; D011549:Pseudomonas / Q000276:immunology / Q000302:isolation & purification*; D011552:Pseudomonas Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013154:Spleen / Q000382:microbiology / Q000473:pathology
references.citation: J Fish Dis. 2004 Apr;27(4):249-53
references.pmid: 15049894
references.citation: J Fish Dis. 2006 Nov;29(11):683-90
references.pmid: 17169115