Z-006. White Blood Cell Borne Chlamydial Prevalence among Alpaca, Sheep, and Goat Cohorts in Western Massachusetts

E. Clark, S. Purdy, W. Webley, E. Stuart;
Univ. of Massachusetts, Amherst, MA.

Chlamydiae, obligate intracellular pathogens, are responsible for a number of medically and economically relevant infectious diseases. While human infection and transmission have and continue to be characterized, less is known regarding infection in animals. Studies have demonstrated that chlamydial species infect various animal groups (e.g. ruminants) and show linkage to several conditions: polyarthritis and spontaneous abortion. Despite the potential gravity of infection, little is known concerning the overall prevalence of Chlamydia strains in these animals. To bridge this information gap, we have surveyed local livestock, including healthy cohorts of alpacas (n=14), sheep (n=11), and goats (n=4) from the Hadley Farm at the University of Massachusetts-Amherst. We also surveyed local farms with female alpacas (n=11) experiencing chronic reproductive problems. In humans, Chlamydia is detectible and can be quantified in buffy coat cells from peripheral circulation. Blood samples were thus collected from each cohort, and vaginal swabs were taken from ill females. Buffy coats, isolated from each blood sample, were divided into two aliquots: one for DNA isolation and the other for culturing with HEp-2 cells. All specimens (buffy coats and swabs) were assayed for chlamydial DNA by PCR (16S rRNA). The presence of viable chlamydial organisms in buffy coats was assessed 96hpi after cells were fixed, stained for Chlamydia, and examined by epifluorescence microscopy. Results from PCR indicate chlamydial DNA was present in 71.4%, 63.6%, and 75%, of normal alpacas, sheep and goats, respectively. Chlamydial DNA was also found in 72.7% of blood samples and 27.2% of vaginal swabs from infertile female alpacas. Viable Chlamydia was found in peripheral blood samples of healthy alpacas (50%), infertile female alpacas (63.6%), sheep (54.4%), and goats (75%). These results suggest that a large percentage of domesticated animals may be harboring infectious chlamydial organisms. Examination and quantification of infected peripheral white blood cells could thus be a new non-invasive diagnostic approach for surveying, tracking, and assessing health and reproduction in food and fiber animals.