Survey and Dynamics of bacteria involved in secondary infections in sheep affected by orf virus

Abstract

In recent decades, secondary infection bacteria quickly increased their pathogenicity in both human and veterinary patients, due to their continuously increasing antibiotic-resistance. When such bacteria intervene in infections as orf in sheep, they can determine an important impact either in the sanitary or in the economic aspect of the brreding sector. Considering the relatively high spread and economic impact of orf in Romanian sheep, this research aimed to estimate the complexity of the secondary infections in diseased sheep in connection with the severity of the lesions displayed. The research was conducted in five herds, on 3 to 96 month old sheep, with orf lesions, scored from mild to severe. The bacteria were isolated from the lesions and identified by cultivation on broth and agar plates plus identification by use of API galleries. The severity of the lesions did not seem to be influenced by the number of bacterial species isolated, but by the herd environment and individual pathogenicity of the isolates.

The cooperation between orf virus and Staphylococcus aureus leads to intractable lesions in skin infection

“…In recent decades, the pathogenicity of bacterial secondary infection in human and animal patients has increased rapidly ( Pastor et al., 2020 ). This has aroused people’s concerns about the health and well-being of herds, environment and biological safety.…”

“…Orf is such a disease that affects the skin, creating a huge gap for S. aureus and also disrupting its O-H program ( Chi et al., 2017 ). This is emphasized by the high detection rate of S. aureus in secondary infection ( Pastor et al., 2020 ). Accordingly, orf can create great convenience for the secondary infection of S. aureus .…”

“…So far, there have been many reports and references about the secondary infection of orf, but there are few systematic studies. Recently, some scholars have made a detailed analysis of the species and quantities of bacteria secondary to orf infection ( Pastor et al., 2020 ). The statistical data had proved that the incidence of secondary infection of orf was 42%, and the detection rate of S. aureus was as high as 58% in the cases of secondary infection.…”

“…The statistical data had proved that the incidence of secondary infection of orf was 42%, and the detection rate of S. aureus was as high as 58% in the cases of secondary infection. In addition, 30% of secondary infections can detect more than two kinds of bacteria ( Pastor et al., 2020 ). Although the biological materials were only collected from five flocks of sheep in Romania, they were very representative of the worldwide prevalence.…”

“…ORFV limits the activity of various cells (through IKK and NF-κB signaling; various virulence factors and immune regulatory molecules) (the red brown part), which facilitates the expansion and penetration of bacteria; and bacteria can also promote the local spread of viruses (the purple part). ( Chan et al, 2006 ; Chen et al, 2016 ; Couñago et al, 2015 ; Diel et al, 2010 ; Diel et al, 2011 ; Fleming et al, 2015 ; Haig, 2006 ; Imlach et al, 2002 ; Khatiwada et al, 2017 ; Lateef et al, 2003; Liu et al, 2021 ; Nagendraprabhu et al, 2017 ; Nardo et al, 2008 ; Ning et al, 2013 ; Pastor et al, 2020 ; Shi et al, 2015 ; Wang et al, 2010 ; Westphal et al, 2009 ; Wise et al, 2012 ; Yu et al, 2020 ; Zecconi and Scali, 2013 ; Zhao et al, 2016 ).…”