The Role of First Line of Defence Mechanisms in the Pathogenesis of Cellulitis in Broiler Chickens: Skin Structural, Physiological and Cellular Response Factors

Abstract

The present study examined several basic attributes of first-line defence mechanisms in the skin as potential factors that may explain the susceptibility of broiler chickens to cellulitis. The variables including structural characteristics of the skin, physicochemical properties and cellular responses to the challenge with pathogens were compared between two categories of chickens, a strain of fast-growing commercial broiler chickens (susceptible to cellulitis) and leghorn chickens (resistant to cellulitis). There were substantial differences between leghorns and broilers with regard to physiological characteristics of the skin. Broiler skin was more amenable to injury and the wound-healing process was slow. Compared with leghorns, the lesions resulting from sub-dermal challenge in broilers were more severe and disseminated over a larger area. Mobilization of phagocytic cells (heterophils and macrophages) in leghorns was brisk even in the areas distant from the site of infection, whereas only few heterophils were recruited in the skin of broilers. The functional competence of heterophils in broilers was inferior when compared with leghorns. Based on the present finding, the predisposition of broilers to cellulitis appears to be primarily associated with the inferior first line of defence of their skin. Broilers in commercial situations may be at higher risk to succumb to even minor infection and eventually develop cellulitis because: (1) structural weaknesses of the skin may predispose broilers to skin injury and thus the risk of skin infection by pathogens is increased; (2) broiler skin surface is more likely to provide a conducive environment for colonization of Escherichia coli; (3) in the event of infection, poor recruitment of phagocytic cells to the site of infection may readily lead to widespread colonization of the tissue by pathogens causing cellulitis and (4) poor functional quality of the phagocytic cells that are mobilized compromise the ability of the host to contain the spread of infection.

Ambient Ozone and Emergency Department Visits for Cellulitis

“…Ozone acting on exposed skin may breach the skins’ barrier function and allow bacteria to penetrate the deeper layers of skin, and/or worsening the symptoms of a pre-existing infection. Animal studies have demonstrated that ozone exposure may cause structural skin damage, which may increase the permeability of the skin to bacteria [ 27 ]. The reliability of this study is enhanced by adequate controlling for the non-linear meteorological confounders, temporal trends (long-term time effects, seasonal cycle, month-of-year impact), and the weekly cycle.…”

Human and Avian Extraintestinal PathogenicEscherichia coli: Infections, Zoonotic Risks, and Antibiotic Resistance Trends

“…Peighambari et al (Peighambari et al, 1995) showed that E. coli isolated from cellulitis lesions were more likely to induce cellulitis lesions in experimentally infected 4-week-old birds than strains of noncellulitis origin. The development of cellulitis lesions in broilers could be due to the weakness of their innate immune response, specifically their heterophils (Olkowski et al, 2005).…”

Principais Causas De Condenação Ao Abate De Aves Em Matadouros Frigoríficos Registrados No Serviço Brasileiro De Inspeção Federal Entre 2006 E 2011

“…Neste estudo, verificou-se que apenas a causa de condenação por dermatose, que é registrada ao abate como qualquer alteração na pele (4) , apresentou uma distribuição sazonal, com a maior ocorrência concentrada no período de inverno, nas principais regiões produtoras. As lesões cutâneas podem ter várias origens e estão relacionados principalmente com deficiências nas condições de manejo nas granjas como alta densidade de criação, excesso de umidade na cama e elevada concentração de amônia no ambiente (21)(22)(23)(24) . Os cuidados de manejo na granja devem ser constantemente monitorados no período de inverno, frente às variações de temperatura observadas principalmente no sul e sudeste do país, para minimizar a ocorrência dos fatores que predispõem à dermatose.…”