title: IFAT and ELISA phase I/phase II as tools for the identification of Q fever chronic milk shedders in cattle.
abstract: Q fever is a widespread zoonotic disease caused by Coxiella burnetii. In cattle the bacterial shedding can persist without symptoms for several months and the shedders identification is a critical issue in the control of the infection at herd level. Following the example of the human protocols for the assessment of Q fever infection status, the aim of this study was the evaluation of the antibody response dynamics to phase I and phase II antigens in C. burnetii shedder dairy cows by means of a phase-specific serology, to verify the suitability of the investigated tools in recognising milk shedders. A total of 99 cows were monitored during time and classified on the basis of serological and PCR results in five groups identifying different shedding patterns. The 297 sera collected in three sampling times were tested by means of ELISA IgG for differential phase I and phase II antibodies detection, while a selection of 107 sera were tested by means of phase specific IgM and IgG IFAT. Both ELISA IgG and IFAT IgG highlighted a low reactivity in non-shedder seropositive animals compared to chronic milk shedder animals. ELISA IgG seemed to perform better than IFAT IgG-IgM, showing significant serological differences among groups that allowed recognising specific serological group patterns, in particular for chronic and occasional milk shedders. These results supported the hypothesis that an animal classification based on phase patterns is reasonable, although it needs to be further investigated.
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy. Electronic address: llucchese@izsvenezie.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Lucchese
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Capello
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, V.le Fiume 78, 36100 Vicenza, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Barberio
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Zuliani
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, University of Utrecht, P.O. Box 80151, 3508 TD Utrecht, The Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: Stegeman
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Ceglie
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Eulalia
authors.initials: E
authors.lastname: Guerrini
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Marangon
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro (PD), Italy.
authors.forename: Alda
authors.initials: A
authors.lastname: Natale
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D016997:Coxiella burnetii / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006801:Humans; D008892:Milk / Q000382:microbiology*; D011778:Q Fever / Q000382:microbiology / Q000662:veterinary*
keywords: Cattle; Chronic milk shedder; Coxiella; Phase I/II; Q fever; Serology