A study of Klebsiella pneumoniae infection in the uterus of the mare.

The study investigates the infection process and impact of Klebsiella pneumoniae in the uterus of mares. The main findings suggest that the infection can persist in the uterus through at least one estrous cycle, with tampons being the more reliable means of isolating and monitoring the bacteria.

Research Design and Procedure

• Using 13 mares, two distinct experiments were conducted. The aim was to stimulate and monitor an intrauterine infection with Klebsiella pneumoniae.
• The initial pilot study created the infection using strains of K pneumoniae type 68 and type 10, which were isolated from the genital tract of stallions with a history of breeding issues.
• The principal study used only K pneumoniae type 68 to instigate infection.
• Instrumentation used to gather uterine samples initially included tampons and guarded culture swabs. Tampons emerged as the more dependable tool for isolating K pneumoniae and thus were applied in the principal study.

Results and Findings

• In both experiments, mares that were inoculated with K pneumoniae became persistently infected at least until the commencement or completion of the post-inoculation estrous cycle. The infection persisted in a number of mares through more than one estrous cycle.
• K pneumoniae counts in the mare’s uterus started to decline after completing the estrous cycle post-inoculation.
• In frozen tissue samples taken from uterine biopsies, K pneumoniae wasn’t detected by fluorescent antibody staining technique.
• The study found post-inoculation sera antibody titers to K pneumoniae were relatively low, being no higher than 1:8, as measured by the capsule swelling method.

Conclusion

• This study has highlighted the proliferative capabilities of Klebsiella pneumoniae in the uterus of the mare. The ability of this organism to maintain infection, at least through one full estrous cycle, could potentially have significant implications for equine reproduction.
• The study also identified the tampon as an effective tool in the isolation of K pneumoniae.
• Despite the persistence of the infection, the observed immune response in mares was relatively low. This raises further questions about how these organisms can evade the host’s immune defenses.