The men behind bActivate

The interest for reproduction has been the overall hall mark of my professional life. I started my professional life as a veterinarian in a large animal practice spending most of the time during the breeding season at a standard bred farm. My interest in reproduction, and in particular in equine reproduction, brought me to California as an equine reproduction resident supervised by professors Barry Ball and Irwin Liu.

Following the residency I made a PhD at the section of Veterinary Reproduction and Obstetrics, Copenhagen University, Denmark, this time focusing on oocyte and early embryonic evaluation and development.

I then took on a position as an assistant professor at the same section. My research focus was now on endometritis in the mare, in particular the most common cause of endometritis – the bacteria Streptococcus equi subspecies zooepidemicus (S.zoo).

Demonstrating localization of S.zoo deep within the endometrium of the chronically infected mare, pursued further investigations in this area. The most significant finding was to demonstrate that S.zoo in the chronically infected mare is able to enter a non-active/dormant state in the endometrium and infusion of a special bacterial growth medium into the uterus can induce active growth of S.zoo, previously residing in dormant bacterial reservoirs. With this finding diagnosis of these previously subclinic infections is now possible.

Data from field studies using bActivate when diagnosing problem mares, indicate that improved diagnosis furthered treatment efficacy and mare fertility. My collaborators and I hope that these findings will improve reproductive efficiency in the mare to the benefit of horses and man. Dr. Petersen has authored 21+ peer-reviewed publications, including a paper in Nature Medicine (2025).

I have had an interest in bacteria-host interactions since I took the infection microbiology course during my veterinary studies. I became a DVM in 2000 and immediately initiated my PhD-project, which also dealt with reproductive tract infection albeit in chickens! In 2003 I defended my PhD and got a faculty position culminating with a professorship in preventive veterinary microbiology in 2012.

I started collaborating with Morten Rønn Petersen investigating Streptococcus equi subspecies zooepidemicus (S. zoo) as a cause of endometritis in mares in 2007.

It was a fantastic experience to discover that 5-10% of mares of all sorts may have a subclinical endometrial infection caused by S. zoo. Later, with the help of particularly Kristina Lu at the Hagyard Equine Medical Insitute, we were able to demonstrate the negative impact of such a subclinical infection as clearing enabled by bActivate virtually restored the live-foal rates to normal (75-80%) and thus re-vitalized mares that had been given up for breeding.

My current research concerning S. zoo is focused on how this organism can switch back and forth from being actively dividing to the dormant state we see in the subclinically infected mares. Understanding the underlying regulatory events during these processes is key to further knowledge on how S. zoo and the endometrial tissue interact. Professor Bojesen has authored 157+ peer-reviewed publications and was an invited speaker at the International Workshop on Equine Endometritis, Al Shaqab, Qatar (2016).