In addition, APEC O1 is one of the most well characterized APEC strains in the literature [37], [42] and [45]. Antimicrobials are commonly used to control colibacillosis in the poultry industry. With rising concern and demonstration of drug resistant bacteria [47], other control methods, such as enhanced host genetics, are a growing area of research. Past experimentation has illustrated the potential for breeding for colibacillosis resistance [2] and [10], indicating that greater research surrounding the genetic control of mechanisms of resistance is needed as a foundation for more effective

breeding programs. Gene expression analysis of immune tissues is commonly used to characterize immune response [13] and [59] and provides potential candidate genes for disease resistance. Expression levels of immune genes have been shown to be heritable [68], evidence that the tactic of genetic VX-770 manufacturer selection for gene expression levels could be successful in a breeding program. The chicken immune system is equipped with several mechanisms to combat pathogens. Multiple tissues each contribute unique signals and functions to help identify

and FDA approved Drug Library manufacturer combat disease. Peripheral blood leukocytes (PBL) are comprised of a dynamic population of cell types that serve in both the innate and adaptive immune responses [20] and [66]. Heterophils, the avian equivalent of neutrophils, are an innate responder and typically the first cell type to fight infection. Heterophils destroy susceptible

bacteria through phagocytosis, oxidative burst and extracellular traps [14] and [22]. Proper signaling by cytokines and T-helper cells can increase the effectiveness of immune response. The defensive mechanisms of APEC can, however, reduce the effectiveness of the innate immune response and may include resistance to the detrimental effects of phagocytosis and complement, or decreasing the antimicrobial activity of heterophils [28], [41], [50], [54] and [58]. Enhanced genetics of the host immune response may allow chickens to overcome APEC’s defenses. Very few publications Methane monooxygenase have documented differences in gene expression between individuals that are resistant vs. susceptible to APEC. We hypothesize that the global transcriptome of peripheral blood leukocytes will differ depending upon vaccination, challenge, and pathological response to APEC. This study aims to determine these gene expression differences associated with an APEC infection, which will lead to a better understanding of the genetic control of resistance and may serve as biomarkers for genetic selection for improved response to APEC infection. APEC O1 strain O1:K1:H7 (NCBI reference sequence: NC_008563.1) was kept in brain heart infusion broth with 10% glycerol at −80 °C. Its genomic sequence is available and has been completely characterized [37].