Combined Effect of Shegandilong Granule and Doxycycline on Immune Responses and Protection Against Avian Infectious Bronchitis Virus in Broilers

Abstract

Infectious bronchitis (IB) causes significant economic losses to commercial chicken farms due to the failures of vaccine immunization or incomplete protection. In this study, we evaluated the combination effect of Shegandilong (SGDL) granule (a traditional Chinese veterinary medicine) and doxycycline on the prevention of IBV infection and injury in the respiratory tract in broilers. A total of 126, 7-day-old broilers were randomly divided into four groups after vaccination. Group I served as a control. Broilers in Group II were given doxycycline, and Group III was given SGDL granule through drinking water. Broilers in Group IV were given SGDL granule and doxycycline by drinking water. Broilers in all groups were challenged with IBV through intraocular and intranasal routes at day 28. Results showed that the anti-IBV antibody level was higher in group IV compared with the level in other groups. Immunohistochemistry and ELISA results showed that an increase of immunoglobulin A (IgA) was observed in the trachea with the maximum level observed at day 14. In addition, SGDL granule + doxycycline effectively inhibited IBV replication and stopped IBV propagation from the trachea to the lung; modulated the mRNA expressions of IL-1β, IL-6, TNF-α, and IFN-γ; and extenuated the histopathology lesions in trachea and lung. These data imply that a combination of SGDL granule and doxycycline is effective in preventing IBV infection and respiratory tract injury in broilers.

Human Wharton’s Jelly Mesenchymal Stem Cells Secretome Inhibits Human SARS-CoV-2 and Avian Infectious Bronchitis Coronaviruses

“…SARS-CoV-2 and IBV are highly infectious coronaviruses and leading causes of morbidity and mortality rates in infected hosts [53][54][55]. Currently, there are no effective methods or proven therapies to control the viral spread and mitigate disease progression for SARS-CoV-2 and IBV infections [56][57][58]. Furthermore, inherited mutagenic characteristics of SARS-CoV-2 and IBV limit the efficacy of available vaccines and exacerbate the disease situations [59,60].…”

Radix Isatidis polysaccharide (RIP) resists the infection of QX-type infectious bronchitis virus via the MDA5/TLR3/IRF7 signaling pathway

“…For instance, Licl has been shown to suppress the inflammatory response induced by IBV by downregulating the inflammation-related genes NF-κB, NLRP3, TNF-α, and IL-1β ( Liu et al., 2022 ). The Chinese medicines Astragalus polysaccharide, forsythoside A, chlorogenic acid, Shegandilong Granule , and Doxycycline was found to modulate the inflammatory response induced by IBV by suppressing NF-κB expression and thus the expression levels of inflammatory factors ( Li et al., 2011 ; Zhang et al., 2017 ; Abaidullah et al., 2021 ; Feng et al., 2021 ). The present study showed that RIP could reduce the expression levels of the inflammatory factors IL-6, IL-8, and IL-1β by decreasing the expression levels of NF-κB, similar to previous studies ( Li et al., 2011 ; Feng et al., 2021 ).…”

The effect of early administration of antibiotics or feeding a diet containing a coccidiostat on inflammatory responses and the morphological structure of selected organs of the immune system in young meat-type turkeys

“…After infection, IgA is synthesized and transported through epithelial cells to the mucosal surface via a secretory component that neutralizes pathogens. As a result, the proliferation of pathogens is limited, but not completely inhibited, and serum IgA levels may be lower due to their secretion at the mucosal surface ( Ganapathy et al, 2005 ; Feng et al, 2021 ). Vaccination of 28-day-old turkeys with a subcutaneously injected inactivated vaccine against ORT had no influence on serum IgA levels, most likely because such vaccines usually induce systemic IgY-dependent immunity, whereas local immune responses involving IgA are limited.…”