Prevalence and Genetic Diversity of Trueperella pyogenes Isolated from Infections in European Bison (Bison bonasus)

Furazolidone reduces the pathogenesis of Trueperella pyogenes and Pseudomonas aeruginosa co-infection in a mouse model

The prevalence of abscess disease significantly limits the population expansion of captive forest musk deer, which is an endangered species protected by the legislation of China. Our prior work had demonstrated that Trueperella pyogenes and Pseudomonas aeruginosa are two important microorganisms in causing the abscess disease of forest musk deer, and furazolidone could inhibit the growth and virulence of the pathogens in vitro. In this study, the in vivo protection activity of furazolidone was evaluated by using mouse models chronically infected with T. pyogenes and P. aeruginosa. The results showed that furazolidone treatment significantly increased the survival rates of mice in the co-infection group, all the mice survived at 14 days post-infection. The damage degree of the lung tissues caused by bacterial infection was ameliorated by the treatment of furazolidone from 7 to 14 days post-infection, which also reduced the residual bacterial burden in the lungs. Compared to the untreated control group, the expression levels of genes activated by the quorum-sensing system of P. aeruginosa and the core virulence regulatory genes of T. pyogenes were significantly suppressed by furazolidone. In addition, the results of transcriptomic analyses showed that 270 DEGs were identified in the co-infection group. This finding further revealed that the immune responses of mice could be enhanced by the treatment of furazolidone, and this might also contribute to the clearance of bacteria from the lungs. Therefore, this study clearly reveals the protection activity of furazolidone against P. aeruginosa and T. pyogenes infection, and thus provides a promising candidate in the treatment of abscess disease.

Prevalence, Virulence Genes, Drug Resistance and Genetic Evolution of Trueperella pyogenes in Small Ruminants in Western China

Trueperella pyogenes is a significant opportunistic pathogen that causes substantial economic losses in animal agriculture due to its ability to infect various animal tissues and organs. Limited research has been conducted on the prevalence and biological characteristics of T. pyogenes isolated from sheep and goats. This study aimed to isolate T. pyogenes from clinical samples of sheep and goats in western China, examining genetic evolutionary relationships, antibiotic resistance, and virulence genes. Between 2021 and 2023, standard bacteriological methods were used to isolate and identify T. pyogenes from 316 samples (209 from goats and 107 from sheep) collected from 39 farms. Susceptibility to 14 antibiotics was tested using broth microdilution per CLSI guidelines, and PCR detected eight virulence genes. Whole-genome sequencing analyzed genetic relationships and gene carriage status in 39 isolates. The results indicated that 86 strains of T. pyogenes were isolated from 316 samples, yielding an isolation rate of 27.2% (goats n = 47, 22.5%; sheep n = 39, 36.4%). The virulence genes plo, cbpA, nanH, nanP, fimA, fimC, and fimE were present in 100%, 66.7%, 64.1%, 71.8%, 69.2%, 59.0%, and 82.1% of isolates, respectively, with none carrying the fimG gene. The dominant virulence genotype was plo/nanH/nanP/fimA/fimC/fimE. The isolates exhibited resistance to erythromycin (44.2%, 38/86), gentamicin (38.4%, 33/86), sulfamethoxazole/trimethoprim (37.2%, 32/86), tetracycline (32.6%, 28/86), and streptomycin (32.6%, 28/86), and low resistance to chloramphenicol (14.0%, 12/86), ciprofloxacin (7.0%, 6/86), penicillin (5.8%, 5/86), and clindamycin (4.7%, 4/86). All isolates were susceptible to cefotaxime, vancomycin, and linezolid. Among the 86 isolates, 37 (43.0%) displayed multidrug resistance (MDR) characteristics. The whole genome sequencing of 39 isolates identified eight types of resistance genes, including ant(2″)-Ia, ant(3″)-Ia, cmlA1, cmx, erm(X), lnu(A), sul1, and tet(W). Except for tet(W), erm(X), and sul1, the other resistance genes were reported for the first time in T. pyogenes isolated in China. The drug susceptibility test results and resistance gene detection for the isolated strains were consistent for tetracycline, erythromycin, gentamicin, and sulfisoxazole. Similar allelic profiles and genetic evolutionary relationships were found among isolates from different farms. This study highlights the antibiotic resistance status and virulence gene-carrying rate of Trueperella pyogenes, providing a basis for clinical medication.

Genetic diversity and virulence properties of caprine Trueperella pyogenes isolates

BACKGROUND

Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in various animal species, including goats. So far, only limited knowledge of phenotypic and genotypic properties of T. pyogenes isolates from goats has been gathered. In our study, we characterized the phenotypic and genotypic properties of caprine T. pyogenes isolates and established their relationship by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR).

RESULTS

From 2015 to 2023, 104 T. pyogenes isolates were obtained from 1146 clinical materials. In addition, two T. pyogenes isolates were obtained from 306 swabs collected from healthy goats. A total of 51 T. pyogenes isolates were subjected to detailed phenotypic and genotypic characterization. The virulence genotype plo/nanH/nanP/fimA/fimC/luxS was predominant. All of the tested isolates showed the ability to form a biofilm but with different intensities, whereby most of them were classified as strong biofilm formers (72.5%). The high level of genetic diversity among tested caprine T. pyogenes isolates (19 different RAPD profiles) was observed. The same RAPD profiles were found for isolates obtained from one individual, as well as from other animals in the same herd, but also in various herds.

CONCLUSIONS

This study provided important data on the occurrence of T. pyogenes infections in goats. The assessment of virulence properties and genetic relationships of caprine T. pyogenes isolates contributed to the knowledge of the epidemiology of infections caused by this pathogen in small ruminants. Nevertheless, further investigations are warranted to clarify the routes of transmission and dissemination of the pathogen.

Contact between European bison and cattle from the cattle breeders' perspective, in the light of the risk of pathogen transmission

Pathogens transmitted between wildlife and domestic animals can pose a threat to endangered species, undermine conservation efforts in wildlife, and affect productivity and parasite control in domestic animals. There are several examples of pathogen transmission between European bison and other animals. The present study surveyed breeders from the vicinity of four large wisent populations in eastern Poland about observed contacts between wisent and cattle. Such contacts were noted by 37% of breeders, indicating a significant risk of contact between European bison and cattle in the study areas, even in the areas where the European bison live mainly in a forest complex, i.e., in the Borecka Forest. A higher potential risk of contacts between European bison and cattle was noted in the Białowieska Forest and the Bieszczady Mountains than in the Borecka and Knyszyńska Forests. In the Białowieska Forest, the risk of viral pathogen transmission resulting from contacts is higher (more direct contacts), and in the case of the Bieszczady Mountains, the probability of parasitic diseases is higher. The chance of contacts between European bison and cattle depended on the distance of cattle pastures from human settlements. Moreover, such contact was possible throughout the year, not only in spring and fall. It appears possible to minimize the risk of contacts between wisent and cattle by changing management practices for both species, such as keeping grazing areas as close as possible to settlements, and reducing the time cattle graze on pastures. However, the risk of contact is much greater if European bison populations are large and are dispersed beyond forest complexes.