<i>Ornithobacterium rhinotracheale</i> Infection in Poultry: an Updated Review

Abstract

Ornithobacterium rhinotracheale is a Gram-negative bacterium of the rRNA superfamily V within the CytophagaFlavobacterium-Bacteroides phylum, which has become an emerging pathogen in the poultry industry. The purpose of this work is to review the current literature on O. rhinotracheale infection in domestic poultry. Despite the difficulties to identify the bacteria using biochemical tests, the polymerase chain reaction (PCR) technique has been successfully used to identify suspected isolates. Moreover, pulsed-field gel electrophoresis (PFGE) has allowed the genetic typing of O. rhinotracheale. Recent investigations carried out in the United States and Argentina described the unusual and extensive β-hemolytic activity of field strains isolated from affected chickens and turkeys. According to the latest serological studies, the causing agent has eighteen serotypes (A to R) and serotype A is the most prevalent among chicken and turkey strains. Gross findings typically found in broiler chickens are unilateral pneumonia, pleuritis, and abdominal airsacculitis with foamy, white yogurt-like exudate, which cause increased condemnation rates at slaughter, whereas those found in turkeys include tracheitis, pneumonia or bronchopneumonia, thoracic and/or abdominal airsacculitis, pericarditis, and peritonitis. Despite the worldwide efforts to control O. rhinotracheale infection, the present situation shows several problems not only because antibiotic treatments appear to be less effective due to the resistance acquired in the poultry industry but also because the vaccines developed so far show variable results in commercial poultry.

A combined retrospective, prospective and experimental study ofOrnithobacterium rhinotrachealeinfection in chickens

“…Tracheal swabs and lung samples were inoculated onto 10% defibrinated goat blood agar plates (Agar Nutritivo, Laboratorios Britania S.A., CABA, Argentina) with 20 µl of gentamicin (Laboratorio Interbiol s.r.l., Victoria, Argentina) and microaerobically incubated at 37°C for 24-48 h. The blood agar plates which showed colonies phenotypically similar to O. rhinotracheale where evaluated for the presence of haemolytic activity for 48 h-postincubation period at room temperature to differentiate between BH and NH isolates as previously suggested (Tabatabai et al, 2010;Gornatti Churria et al, 2011, 2012Walters, 2014;Walters et al 2014).…”

“…It was first isolated and characterized by Charlton et al (1993) from Californian commercial turkeys with respiratory disorders, and belongs to the Flavobacteriaceae family, Bacteroidetes phylum and Chryseobacterium clade (McBride, 2014). O. rhinotracheale was first identified as a non-haemolytic (NH) bacterium (Chin & Charlton, 2008;Gornatti Churria et al, 2012;Boulianne et al, 2013;Chin et al, 2013), but unusual and extensive β-haemolytic (BH) activity was subsequently identified in field isolates obtained from commercial chicken and turkey flocks with severe respiratory signs and mortality in Argentina and the US (Gornatti Churria et al, 2012;Walters, 2014;Walters et al, 2014).…”