Co-infection of broilers with Ornithobacterium rhinotracheale and H9N2 avian influenza virus

Abstract

BackgroundSince 2008, a progressive pneumonia has become prevalent in broilers and laying hens. This disease occurrs the first day after hatching and lasts more than 30 days, resulting in approximately 70% morbidity and 30% mortality in broilers. The objective of this study was to isolate and identify the pathogens that are responsible for the progressive pneumonia and establish an animal model for drug screening.Results193 serum samples were collected from 8 intensive farms from 5 provinces in China and analysed in the current research. Our clinical survey showed that 65.2% to 100% of breeding broilers, breeding layers, broilers and laying hens were seropositive for ORT antibodies. From 8 intensive farms, six ORT isolates were identified by PCR and biochemical assays, and two H9N2 viruses were isolated. Newcastle Disease Virus (NDV) and Infectious BronchitisVirus (IBV) were excluded. Typical pneumonia and airsacculitis were observed both in broilers inoculated intraperitoneally with an ORT isolate alone and in those co-infected with ORT and H9N2 virus isolates. Specifically, the survival rate was 30%, 20%, 70%, 50% and 90% in birds inoculated with ORT+H9N2 virus, ORT followed by H9N2 virus, H9N2 virus followed by ORT, and ORT or H9N2 virus alone, respectively.ConclusionsThe results of this study suggest that ORT infections of domestic poultry have been occurring frequently in China. ORT infection can induce higher economic losses and mortality if H9N2 AIV is also present. Although the isolation of ORT and H9N2 virus has been reported previously, there have been no reported co-infections of poultry with these two pathogens. This is the first report of co-infection of broilers with ORT and H9N2 virus, and this co-infection is probably associated with the outbreak of broiler airsacculitis in China, which has caused extensive economic losses.

Mycoplasma gallisepticum modifies virus shedding and immune response of Newcastle disease virus in broilers

“…Similarly, severe clinical disease was reported after co-infection with MG and H3N8, which further confirms the severity of MG co-infections (Stipkovits et al 2012a, b). Similar findings were reported when chickens were infected with H9N2 in combination with Staphylococcus aureus or Avobacterium paragallinarum or Ornithobacterium rhinotracheal (Kishida et al 2004, Pan et al 2012. Co-infection studies of influenza virus and Streptococcus pneumoniae in mice promoted bacterial colonization in the presence of viral infection (Nakamura et al 2011).…”

Ornithobacterium rhinotracheale infection in red wattled lapwings (Vanellus indicus) in Pakistan - a case report

“…A total of 18 birds were affected by respiratory illness, out of which 3 (16.7%) birds died. The most common gross findings were tracheitis, unilateral pneumonia, and abdominal airsacculitis, with a foamy, white yogurt-like exudate, as described previously (HAFEZ, 2002;HAFEZ and LIERZ 2010;PAN et al, 2012;CHURRIA et al, 2012). Histopathological examination revealed acute fibrinous air sacculitis, oedema and congestion of the lungs.…”

“…Polymerase Chain Reaction (PCR) was used for molecular identification of the agent based on 16S rRNA fragment amplification, as described previously (HAFEZ, 2002;PAN et al, 2012). The forward and reverse primers used were S. Umar et al: Ornithobacterium rhinotracheale infection in lapwings 5'-GAGAATTAATTTACGGATTAA-3' and 5'-TTCGCTTGGTCTCCGAAGAT-3' respectively.…”

Evolutionary trajectories and diagnostic challenges of potentially zoonotic avian influenza viruses H5N1 and H9N2 co-circulating in Egypt

“…However, infections complicated by other opportunistic co-pathogens might enhance mortality (Pan et al, 2012). Among viruses of subtypes H5 and H7 highly pathogenic (HP) biotypes exist that may cause up to 100% mortality especially among galliform poultry (Alexander, 2007).…”