FATAL CASE OF STREPTOCOCCUS SUIS INFECTION IN A YOUNG WILD BOAR (SUS SCROFA) FROM SOUTHWESTERN SPAIN.

Streptococcus suis is a recognized pathogen that may cause important diseases in pigs and humans. This microorganism has been repeatedly isolated from wild boar (Sus scrofa). However, its health implications for this wild species are still unknown. This article reports a detailed description of a fatal case of septicemia by S. suis affecting a young wild boar. The affected animal, about 15 days old, was found near death and exhibiting neurologic signs at a wild boar estate in southwestern Spain. Postmortem examination showed generalized congestion, brain hemorrhages and lobular pneumonia. Histopathological evaluation demonstrated the presence of meningitis and encephalitis with marked congestion and suppurative bronchopneumonia. Streptococcus suis serotype 2 isolates exhibiting important virulence factors (extracellular factor, muramidase-released protein, and suylisin) were isolated from the affected animal. This study confirms the presence of potentially virulent and zoonotic strains of S. suis in wild boar from Spain.

Ocular lesions associated with Chlamydia suis in a wild boar piglet (Sus scrofa) from a semi-free range population in Spain.

The role of the wild boar (Sus scrofa) as a reservoir for a large number of pathogens that can affect both domestic animals and humans has been widely studied in the last few years. However, the impact of some of these pathogens on the health of wild boar populations is still being determined. This article presents a clinical case of severe bilateral keratoconjunctivitis affecting a 2-mo-old piglet from a semi-free range population in Spain. Histopathologic and microbiologic analysis revealed lesions in the cornea, choroid, and optical nerve, and Chlamydia suis was detected in the eyes bilaterally. The visual handicap resulting from this type of lesion greatly affects the survival of this affected piglet.

Isolation of Aeromonas hydrophila in the respiratory tract of wild boar: pathologic implications.

Aeromonas hydrophila has been repeatedly reported as an animal pathogen. This study describes a case of a wild boar piglet in Spain with severe purulent pneumonia caused by A. hydrophila. To confirm the presence of A. hydrophila in the respiratory tract of wild boars from the same region, lung samples from 34 adult hunted animals and nasal samples from 12 live animals were collected and cultured in selective medium. Lung lesions were studied in hunted wild boars to determine the presence of A. hydrophila and to assess its role as a possible respiratory pathogen in wild boars. A. hydrophila was isolated in 10.87% of the animals studied (8.82% of the dead animals and 16% of the live animals). However, its presence in the lungs of adults could not be correlated with the lesions found. Thus, the role of A. hydrophila as a respiratory pathogen is likely to be influenced by other factors, such as age, immunologic status, or coinfection with other pathogens. As a zoonotic pathogen, the presence of A. hydrophila in wild boars may pose a potential risk to people who consume their flesh.

Severity of bovine tuberculosis is associated with co-infection with common pathogens in wild boar.

Co-infections with parasites or viruses drive tuberculosis dynamics in humans, but little is known about their effects in other non-human hosts. This work aims to investigate the relationship between Mycobacterium bovis infection and other pathogens in wild boar (Sus scrofa), a recognized reservoir of bovine tuberculosis (bTB) in Mediterranean ecosystems. For this purpose, it has been assessed whether contacts with common concomitant pathogens are associated with the development of severe bTB lesions in 165 wild boar from mid-western Spain. The presence of bTB lesions affecting only one anatomic location (cervical lymph nodes), or more severe patterns affecting more than one location (mainly cervical lymph nodes and lungs), was assessed in infected animals. In addition, the existence of contacts with other pathogens such as porcine circovirus type 2 (PCV2), Aujeszky's disease virus (ADV), swine influenza virus, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Haemophilus parasuis and Metastrongylus spp, was evaluated by means of serological, microbiological and parasitological techniques. The existence of contacts with a structured community of pathogens in wild boar infected by M. bovis was statistically investigated by null models. Association between this community of pathogens and bTB severity was examined using a Partial Least Squares regression approach. Results showed that adult wild boar infected by M. bovis had contacted with some specific, non-random pathogen combinations. Contact with PCV2, ADV and infection by Metastrongylus spp, was positively correlated to tuberculosis severity. Therefore, measures against these concomitant pathogens such as vaccination or deworming, might be useful in tuberculosis control programmes in the wild boar. However, given the unexpected consequences of altering any community of organisms, further research should evaluate the impact of such measures under controlled conditions. Furthermore, more research including other important pathogens, such as gastro-intestinal nematodes, will be necessary to complete this picture.

Fatal outbreak of systemic pasteurellosis in a wild boar (Sus scrofa) population from southwest Spain.

Pasteurella multocida is a common pathogen of swine that causes specific diseases with great economic impact. However, the importance of this pathogen in wild boar is still unknown. In the current work, an outbreak of systemic pasteurellosis in wild boar with a high mortality rate is described. A total of 23 wild boar of all ages were found dead over a 5-day period on a game estate in southwest Spain (11.11% mortality). Three animals were necropsied and showed subcutaneous edema, a generalized congestion, and fibrin deposits in the peritoneal cavity. Hemorrhages, general congestion, and intravascular thrombosis were microscopically observed. Pasteurella multocida type B was isolated from all of the studied organs. Outbreaks of systemic pasteurellosis have been described in domestic pigs from Asia and Australia, but not to date in Europe. This outbreak suggests that systemic pasteurellosis affecting wild boar populations may be an important cause of mortality.