Actinomyces hyovaginalis associated with disseminated necrotic lung lesions in slaughter pigs

Insight into the intestinal microbiome of farrowing sows following the administration of garlic (Allium sativum) extract and probiotic bacteria cultures under farming conditions

Background

Due to the tendency to reduce antibiotic use in humans and animals, more attention is paid to feed additives as their replacement. Crucial role of feed additives is to improve the health status, production efficiency and performance. In this original research, we estimate the potential influence of garlic (Allium sativum) extract and probiotic formula including Enterococcus faecium, Lactobacillus rhamnosus and Lactobacillus fermentum on the intestinal microbiota of sows, using the next generation sequencing method (NGS).

Results

Our results indicate that the overall species richness as well as the composition of swine gut microbiota may be shaped by regular feeding with supplemented additives. On the Family and Genus level both additives (garlic extract and probiotics) seem to decrease microbiome diversity and richness. However, when it comes to garlic supplementation, we found the opposite trend on the Species level.

Conclusions

The analysis of the selected microbial function indicates that both additives used in this study (garlic extract and composition of probiotics) seem to create a greater metabolic potential than estimated in a control group of sows. A general trend of losing or decreasing members of pathogenic species in the swine microbiome seems to occur in relation to both supplemented additives. In the prevention of some bacterial diseases supplemented additives could be considered for future use.

Isolation of Actinomyces hyovaginalis from sheep and comparison with isolates obtained from pigs

Actinomyces hyovaginalis, an organism initially described from pigs, was recovered from nine sheep and a moufflon. Further strains of A. hyovaginalis were recovered from five samples from pigs over the same period. 16S rRNA sequencing and extensive phenotyping demonstrated high similarity between the ovine and porcine isolates; however differences with respect to erythritol, adonitol and l-arabitol fermentation were detected. Ovine isolates were made from various sample sites including abscesses and highlight the importance of the accurate identification of the various coryneform isolates which affect sheep. A. hyovaginalis can be added to the growing list of coryneforms which can cause disease in sheep including Corynebacterium pseudotuberculosis, Trueperella pyogenes and Arcanobacterium pluranimalium.

Actinomyces hyovaginalis-associated lymphadenitis in a Nubian goat

A 6-year-old Nubian goat with a history of progressive weight loss and cough was presented for necropsy. The goat tested negative for antibodies to caseous lymphadenitis and caprine arthritis and encephalitis by hemagglutination inhibition assay and enzyme-linked immunosorbent assay, respectively. Postmortem examination revealed marked enlargement and, with histopathology, a fibrinopurulent necrotizing lymphadenitis of a tracheobronchial lymph node, with an appearance similar to that reported in cases of caseous lymphadenitis. An organism characterized by molecular methods as Actinomyces hyovaginalis was isolated together with Staphylococcus spp. and Streptococcus spp. from the lesion. No Corynebacterium pseudotuberculosis was recovered. To the authors' knowledge, this is the first isolation of A. hyovaginalis from a goat. Although the exact contribution of A. hyovaginalis to the lesion remains to be established, this case demonstrates that A. hyovaginalis should be considered in cases of caseous lymphadenitis-type lesions, especially when C. pseudotuberculosis has been excluded.

Carcass condemnation causes of growth retarded pigs at slaughter

Condemnation causes of growth retarded pigs were studied in a Spanish abattoir. A total of 513 carcasses out of 6017 (8.5%) were rejected during inspection. The main reasons for condemnation were abscesses, cachexia, catarrhal bronchopneumonia, vertebral osteomyelitis, arthritis, pleuritis, peritonitis and pleuropneumonia. Positive relationships were found between tail lesions and arthritis (OR=5.23) or vertebral osteomyelitis (OR=24.81), while no relationships were found between tail lesions and abscesses. Lower risks were observed among carcasses condemned for cachexia, and were as follows: abscesses (OR=0.18), arthritis (OR=0.32), vertebral osteomyelitis (OR=0.06). Arcanobacterium pyogenes, either alone or in combination with other agents, was the main bacterial species isolated from abscesses, osteomyelitis and arthritis (73.5% of lesions). Direct economical losses associated with condemnation were calculated to be 30,000 Euro.