A HEADACHE FROM OUR PAST? INTRACRANIAL ABSCESS DISEASE, VIRULENCE FACTORS OF TRUEPERELLA PYOGENES, AND A LEGACY OF TRANSLOCATING WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS)

Abstract

Trueperella pyogenes, a bacterial opportunistic pathogen residing along the skin layer of apparently healthy animals, is the etiologic agent of intracranial abscessation-suppurative meningoencephalitis, a cause of mortality for male white-tailed deer ( Odocoileus virginianus). Occurrence of this disease has been speculated to be influenced by virulence of T. pyogenes residing on white-tailed deer in geographically distinct metapopulations. To determine if differences in virulence potential of T. pyogenes could affect occurrence of disease across populations, we examined if frequency of seven virulence genes of T. pyogenes from forehead swabs of 186 apparently healthy white-tailed deer differed between sites in the state of Georgia, US, where ≥1 male tested positive for a cranial abscess and sites where no individuals tested positive for a cranial abscess. We detected six of seven virulence genes more frequently at sites where we detected ≥1 male with a cranial abscess compared to sites where we did not detect any individuals with a cranial abscess ( nanH, P<0.001; nanP, P=0.007; fimA, P<0.001; fimC, P=0.037; fimE, P<0.009; fimG, P<0.001; and cbpA, P=0.872). Our findings suggest differences in the pathogenic potential of T. pyogenes at individual sites may help to explain spatial variability of this disease. Anecdotally, the incidence of cranial abscess disease in Georgia seems to be associated with areas that were restocked with white-tailed deer from a high-fenced property in Wisconsin, US. Given the spatial distribution of this disease, we speculate that these genetic differences in T. pyogenes may have arisen from white-tailed deer restocking efforts, and our observations may be a legacy of an introduced disease manifesting itself generations later.

Pathogenicity and Virulence of Trueperella pyogenes: A Review

“…In wildlife, T. pyogenes may be associated with many types of purulent disorders occurring in free-living and captive animals. T. pyogenes infections were reported the most frequently in ruminants and other herbivores, in which the bacteria were also found as a resident microbiota of the skin and mucous membranes of respiratory and urogenital tracts [20,54,124].…”

“…In the United States and Canada, T. pyogenes is an emerging pathogen of captive or free-ranging white-tailed deer ( Odocoileus virginianus ), which cause intracranial abscessation—suppurative meningoencephalitis disease complex (the intracranial abscess disease) that occurs with a variable frequency, depending on animal populations [54,124,125,126,127]. T. pyogenes may be also involved in pneumonia and necrobacillosis occurring in this animal species [128,129].…”

“…This finding indicates the genetic heterogeneity in the studied T. pyogenes populations. On the other hand, Cohen et al [124] detected significantly more virulence genes in T. pyogenes isolates from populations of white-tailed deer males, in which a high incidence of the intracranial abscess disease was observed, compared with those detected in the isolates from apparently healthy animals in populations in which the disease was not noted. This finding suggests that the essential differences in the pathogenic potential may exist among T. pyogenes strains, depending on their origin.…”

Suppurative meningoencephalitis secondary to a Trueperella pyogenes-induced mandibular abscess in a free-ranging gray brocket deer (Mazama gouazoubira)

“…It is largely distributed in Brazil, Uruguay, Argentina, Paraguay, and Bolivia. M. gouazoubira is the most common Cervidae species in these areas, occupying a large variety of biomes (4,7). This species has a solitary behavior.…”

“…Trueperella pyogenes is an emerging pathogen of captive or free-ranging white-tailed deer (Odocoileus virginianus) (3,7,14,31,32). This bacterium has been isolated as the etiological agent associated with chronic purulent infections in other species of deer, including the red deer (Cervus elaphus), key deer (Odocoileus virginianus clavium), fallow deer (Dama dama), forest musk deer (Moschus berezovskii), roebuck (Capreolus capreolus), and mule deer (Odocoileus hemionus) (1,15,18,21,33,34,35).…”