Accession Number : ADA551713


Title :   Assessment of the Duration of Protection in Campylobacter jejuni Experimental Infection in Humans


Descriptive Note : Journal article


Corporate Author : NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD


Personal Author(s) : Tribble, David R ; Baqar, Shahida ; Scott, Daniel A ; Oplinger, Michael L ; Trespalacios, Fernando ; Rollins, David ; Walker, Richard L ; Clements, John D ; Walz, Steven


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a551713.pdf


Report Date : Jan 2010


Pagination or Media Count : 11


Abstract : A human Campylobacter jejuni infection model provided controlled exposure to assess vaccine efficacy and investigate protective immunity for this important diarrheal pathogen. A well-characterized outbreak strain, C.jejuni 81-176, was investigated using a volunteer experimental infection model to evaluate the dose range and duration ol' protection. healthy Campylobacter-seronegntive adults received C. jejuni strain 81-176 via oral inoculation of 105 , 107 , or 109 CFU (5 adults/dose), which was followed hy clinical and immunological monitoring. Based on dose range clinical outcomes, the 109-CFU dose (II= 31) was used to assess homologous protection at 28 to 49 days (short-term veterans [S'IV]; n = 8) or 1 year (long-term veterans [L1V]; = 7) after primary infection. An illness dose effect was observed for naive subjects (with lower doses, 40 to 60% of the subjects were ill; with the 109 -CFU dose, 92% of the subjects were ill) along with complete protection for the STV group and attenuated illness for the LTV group (57%). Partial resistance to colonization was seen in S'IV (25% of the subjects were not infected; 3-log-lower maximum excretion level). Systemil' and mucosal immune responses were robust in na'ive subjects irrespective of the dose or the severity of illness. In contrast, in S'IV there was a lack of' circulating antibody-secreting cells (ASC), reflecting the local mucosal eft'ector responses. L1V exhibited comparable ASC responses to primary infection, and anamnestic fecal lgA responses likely contributed to self-resolving illness prior to antibiotic treatment. Cnmpylobacter antigen-dependent production of gamma interferon by peripheral blood mononuclear cells was strongly associated with protection from illness, supporting the hypothesis that THI polarization has a primary role in acquired immunity to C. jejuni.


Descriptors :   *DIARRHEA , *EXPOSURE(PHYSIOLOGY) , *INFECTIOUS DISEASES , *STRAINS(BIOLOGY) , ANTIBIOTICS , BLOOD CELLS , CIRCULATION , CLINICAL MEDICINE , DOSAGE , ILLNESS , IMMUNITY , MUCOUS MEMBRANES , PROTECTION , RESISTANCE(BIOLOGY) , RESPONSE(BIOLOGY) , SPIRILLACEAE , VACCINES


Subject Categories : Medicine and Medical Research
      Microbiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE