Porcine Respiratory Disease Complex and Biofilms

Respiratory disease in pigs is common in modern pork production worldwide and is often referred as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. As a true multifactorial disease; environmental conditions, population size, management strategies and pig-specific factors such as age and genetics play critical roles in the outcome of PRDC. Pathogens involved in respiratory disease in pigs vary significantly among farms, production sites, regions and countries, difficulting the treatment and control of the PRDC. The interaction that occurs on the cellular and molecular levels during concurrent infection of pigs with two or more respiratory pathogens is multi-faceted and complex. Rates of morbidity related to PRDC range from 30% to 70%, and mortality rates vary between 4 and 6 percent, which could be even higher in affected farms

 

 
There are a variety of viral and bacterial pathogens commonly associated with PRDC. The main bacteria associated to PRDC includes:Actinobacillus pleuropneumoniae, Streptococcus suis , Pasteurella multocida , Bordetella bronchiseptica, Haemophilus pasaruis and Mycoplasma hyopneumoniae. Respiratory pathogens can be further distributed into primary pathogens that are capable of inducing severe lesions in respiratory tissues as a result of their own virulence (A. pleuropneumoniae , B. bronchiseptica and M. hyopneumoniae ), and secondary or opportunistic infectious pathogens, which typically need help from others co-infecting pathogens or co-factors, in order to induce substantial lesions in the respiratory system (S. suis , P. multocida and H. parasuis )..