Effect of low-pathogenicity influenza virus H3N8 infection onMycoplasma gallisepticuminfection of chickens

Abstract

Mycoplasma infection is still very common in chicken and turkey flocks. Several low-pathogenicity avian influenza (LPAI) viruses are circulating in wild birds that can be easily transmitted to poultry flocks. However, the effect of LPAI on mycoplasma infection is not well understood. The aim of the present study was to investigate the infection of LPAI virus H3N8 (A/mallard/Hungary/19616/07) in chickens challenged with Mycoplasma gallisepticum. Two groups of chickens were aerosol challenged with M. gallisepticum. Later one of these groups and one mycoplasma-free group were aerosol challenged with the LPAI H3N8 virus. The birds were observed for clinical signs for 8 days, then euthanized, and examined for the presence of M. gallisepticum in the trachea, lung, air sac, liver, spleen, kidney and heart, and for developing antimycoplasma and anti-viral antibodies. The LPAI H3N8 virus did not cause any clinical signs but M. gallisepticum infection caused clinical signs, reduction of body weight gain and colonization of the inner organs. These parameters were more severe in the birds co-infected with M. gallisepticum and LPAI H3N8 virus than in the group challenged with M. gallisepticum alone. In addition, in the birds infected with both M. gallisepticum and LPAI H3N8 virus, the anti-mycoplasma antibody response was reduced significantly when compared with the group challenged with M. gallisepticum alone. Co-infection with LPAI H3N8 virus thus enhanced pathogenesis of M. gallisepticum infection significantly.

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

“…Delayed viral clearance in MG infected birds could be the other possible reason for enhanced replication and pathogenicity. 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.…”

“…Virus isolation (VI) and quantification were performed to determine virus shedding in B and C swabs as previously described (Stipkovits et al 2012a;Kaerber, 1931) and reported as mean embryo infectious dose (EID 50 / 0.1 ml) on a Log 10 scale.…”

“…Mycoplasma monitoring: MG antibodies were checked by rapid plate agglutination (RPA) and monoclonal-based blocking enzyme-linked immunosorbent assays (ELISAs) (MYGA test and MYSY test; Diagnosztikum Kft, Budapest, Hungary) as described previously (Feberwee et al 2005;Stipkovits et al 2012a). …”

Virus Shedding in Co-Infections of Low Pathogenic Avian Influenza Virus (H6n2) and Lentogenic Newcastle Disease Virus (La Sota) in Numida Meleagris

“…Concomitant infection could exacerbate the course of the disease, leading to mixed clinical signs, increased mortality and pathological findings could differ from the usual ones (4). What is more, co-infection with two viruses could alter their tropism and hence, to erroneous diagnosis (1,5).…”

Development of a loop-mediated isothermal amplification targeting a gene within the pyruvate dehydrogenase complex, the pdhA gene, for rapid detection of Mycoplasma gallisepticum

“…7,14 Crucially, coinfection with other bacterial and/or viral pathogens dramatically increases morbidity and mortality, including Escherichia coli, Newcastle disease virus, avian Influenza A virus, and infectious bronchitis virus (Avian coronavirus). 11,23,26 Although the culture-based procedure is considered to be the gold standard for definitive diagnosis, M. gallisepticum culture is time-consuming and laborious, usually requiring 7-30 days to obtain the result. 24 Furthermore, the results of culture are often obscured by overgrowth or nutrient depletion by other bacteria.…”