** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** CAMPYLOBACTER JEJUNI IS A MAJOR CONCERN FOR FOOD SAFETY, ANIMAL HEALTH, AND PUBLIC HEALTH. TWO ZOONOTICALLY IMPORTANT C. JEJUNI STRAINS WILL BE UTILIZED DURING THIS STUDY, C. JEJUNI CLONE SA (SHEEP ABORTION STRAIN) AND REFERENCE HUMAN PATHOGENIC STRAIN C. JEJUNI 11168. SMALL RNAS (SRNAS) HAVE BEEN DEMONSTRATED TO BE EXPRESSED BY C. JEJUNI, BUT LITTLE IS KNOWN ABOUT THEIR REGULATORY MECHANISMS AND PHYSIOLOGICAL FUNCTIONS. OUR PRELIMINARY RESEARCH HAS DEMONSTRATED THAT TWO C. JEJUNI SRNAS (CJNC110 AND CJNC140) DIRECTLY AFFECT PHENOTYPES NECESSARY FOR SURVIVAL, INCLUDING PHENOTYPES CONNECTED TO BIOFILM FORMATION. THE GOAL OF THE PROPOSED RESEARCH IS TO DECIPHER THE REGULATION OF BIOFILM FORMATION BY SMALL RNAS CJNC110 AND CJNC140. THE CENTRAL HYPOTHESIS IS THAT SRNA CJNC110 AND CJNC140 REGULATE BIOFILM FORMATION AND THAT THEIR ABILITY TO REGULATE BIOFILM FORMATION CONTRIBUTES TO CHICKEN COLONIZATION. TO TEST THIS HYPOTHESIS, I PROPOSE THE FOLLOWING OBJECTIVES:OBJECTIVE # 1:DETERMINE THE MOLECULAR AND PHENOTYPIC ROLES OF SRNA CJNC140 AND CJNC110 REGULATION DURING BIOFILM FORMATION.OBJECTIVE # 2:CONDUCT COMPETITIVE FITNESS ASSAYS AND RNASEQ TO REVEAL CHICKEN COLONIZATION AND ENVIRONMENTAL SURVIVAL DETERMINANTS MODULATED BY CJNC110 AND CJNC140.THIS TRAINING GRANT WILL SUPPORT FOOD SAFETY, NUTRITION, AND HEALTH, AND OUTCOMES WILL SUPPORT FOOD AND NUTRITION TRANSLATION. CRITICALLY, TRAINING WILL SUPPORT THE POST-DOCTORAL APPLICANT WHO IS INTERESTED IN MICROBES AFFLICTING AGRICULTURE. OUR OBJECTIVES ARE INNOVATIVE BECAUSE CHARACTERIZING THE MOLECULAR MECHANISMS OF C. JEJUNI BIOFILM FORMATION IN ASSOCIATION WITH SRNAS COULD PROVIDE NOVEL TARGETS FOR DRUG DEVELOPMENT, ULTIMATELY REDUCING CAMPYLOBACTER PERSISTENCE PRE- AND POST-HARVEST OF THE CHICKEN RESERVOIR.