Actinomyces (A.) hyovaginalis is a Gram-positive, rod-shaped, polymorphic bacterium. In domestic pigs, the infection is typically associated with pyogranulomatous pneumonia. In wild boars, this infection was never associated with such lesion. We report the gross, histopathological, and bacteriological findings in a case of pyogranulomatous pneumonia caused by A. hyovaginalis infection in a free-ranging wild boar. Fragments of the lungs, lymph nodes, and heart from a wild boar were sent by boar hunters for histopathological analysis with a presumptive tuberculosis diagnosis. Grossly, in the lungs, there were multiple nodules of 0.1 to 0.8 cm in diameter, with light-yellow, opaque, friable necrotic centers. Histologically, these nodules were composed of coagulative necrosis, with abundant amorphous to granular eosinophilic material, neutrophilic inflammatory infiltrate, cellular debris, multifocal mineralization, and numerous intralesional extracellular coccobacillary basophilic bacterial colonies within the necrotic centers. Surrounding these areas, there were concentric layers of a marked inflammatory infiltrate of lymphocytes, plasma cells, macrophages, epithelioid macrophages, and neutrophils. The Brown-Hopps stain evidenced intralesional Gram-positive bacilli. In bacterial culture, small white partial hemolytic colonies were identified in 5

We report here the first confirmed case of a pituitary abscess in a calf caused by Helcococcus ovis, an emerging pyogenic bacterium in veterinary medicine. An 8-month-old calf showed progressive neurological signs following the use of a nose ring. Gross and histopathological examination revealed a large abscess in the pituitary gland accompanied by leptomeningitis, encephalitis, and plexus choroiditis. Helcococcus ovis was isolated from the pituitary abscess and identified by MALDI-TOF mass spectrometry with high confidence. Coccoid gram-positive bacteria were observed on gram stain of formalin-fixed tissues from leptomeningitis, plexus choroiditis and pituitary abscess lesions. Gross and histological features were indistinguishable from abscesses caused by other pyogenic organisms, highlighting the critical importance of bacteriological culture to diagnosis. This case expands the known pathogenic spectrum of H. ovis and suggests its inclusion in the differential diagnosis of suppurative central nervous system lesions in cattle.

Streptococcus suis (S. suis) causes systemic disease in piglets mainly at the nursery phase. In Brazil, an increase in outbreaks caused by serotype 9 strains has been a challenge in the last few years. As the nasal cavity is the first line of defense against respiratory agents, this study aimed to characterize the nasal microbiota of piglets systemically infected with S. suis. Nasal swabs were collected from two groups (healthy and diseased piglets) from three farms. After the DNA extraction, the V4 region of 16S rRNA was amplified and submitted to metabarcoding sequencing. A series of bioinformatic analyses was performed to investigate the diversity and composition of the nasal bacterial community and metabolic pathways associated with both groups. Histopathological and bacteriological examination confirmed that all diseased animals had systemic infection by S. suis serotype 9. The diseased group showed significantly lower alpha diversity and distinct beta diversity compared to the healthy group. The nasal microbiota of the diseased group was enriched by Streptococcaceae family and Streptococcus genus. Conversely, gut-associated bacteria were enriched in the healthy group (Bacteroidota, Lachnospiraceae, Prevotellaceae, and Ruminococcaceae). Four metabolic pathways were enriched in the diseased group (Phosphomannomutase, Phenylacetyl-CoA 1,2-epoxidase, Ferrochelatase, and Membrane alanyl aminopeptidase) and could be associated with S. suis infection. In conclusion, this study brings the identification of a nasal dysbiotic profile associated with systemic S. suis serotype 9 infection and an unexpected enrichment of gut-associated taxa in healthy pigs.

Southern right whales (Eubalaena australis) are mysticete cetaceans commonly observed in the coastal waters of Brazil, particularly in Santa Catarina State. There is limited understanding of the causes of calf mortality in this species, particularly concerning infectious diseases. We report a case of omphalophlebitis caused by Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) that led to septicemia in a Southern right whale calf. Gross examination revealed an incompletely healed umbilicus with fibrin deposition and amorphous yellow material present in the lumen of the umbilical vein on the cut surface. The main histopathological findings showed fibrinosuppurative omphalophlebitis with numerous coccoid basophilic bacterial aggregates. These aggregates were also observed in the lamina propria, submucosa, and muscular layers of the small intestine and uterus, as well as in the interstitium of the kidneys and within blood vessels of the skin, skeletal muscle, heart, and ovaries. Tissue samples taken from the umbilicus and uterus were inoculated on 5% sheep blood agar and MacConkey agar. Small, transparent colonies that exhibited complete hemolysis were identified on blood agar. Gram staining revealed the presence of Gram-positive cocci arranged in chains. The bacterial isolate was analyzed using the MALDI-TOF technique, which confirmed its identity as S. zooepidemicus. The presence of S. equi antigen in the extra-umbilical aggregates was confirmed through immunohistochemistry. These findings underscore the significance of streptococcal infections in cetaceans and contribute valuable data regarding calf mortality in baleen whales. Furthermore, we provide new insights into the understanding of marine ecosystem health markers.

Streptococcus suis (S. suis) is a pathogen associated with pigs and human meningitis. Previous studies indicate wild boars (Sus scrofa) as a S. suis reservoir; however, in Brazil this has not yet been assessed in free-ranging wild boars. Therefore, this study aimed to identify the frequency of S. suis in wild boar samples from South Brazil. For that, convenient lung and lymph node samples collected during 2013, 2014, 2015, and 2019 of free-ranging wild boars from Rio Grande do Sul, South Brazil were evaluated. The detection of S. suis was based on the presence of gdh (glutamate dehydrogenase) gene by real-time PCR. Histopathological and immunohistochemical (IHC) analyses were performed to identify lesions associated with the presence of S. suis in positive samples. The results revealed S. suis gdh detection in 4% (5/78) of lung samples and 1.05% (1/95) of lymph node samples. All of the positive animals were from an environmental reserve in Barra do Ribeiro city. No association of S. suis DNA, antigen or lesions was identified in the positive animals. Although there are some limitations due to convenience sampling, lack of upper respiratory samples, and specific geographic localization, this study provides the first insights into the frequency of S. suis in Brazil.

AIMS:Pyometra and cystitis caused by Escherichia coli are common diseases identified in canine or feline females. The origin of pyometra infection remains uncertain, and effective prevention strategies for this disease are still unknown. This study aimed to provide a phenotypic characterization, including antimicrobial resistance and virulence profiles, of endometrial pathogenic (EnPEC) and uropathogenic (UPEC) E. coli strains isolated simultaneously from the same animal.METHODS AND RESULTS:Sixteen E. coli strains, from eight different animals, were analyzed in this study. The antimicrobial susceptibility profile of EnPEC and UPEC strains was determined using the disc diffusion method, which showed a similar susceptibility profile among strains (EnPEC and UPEC) from the same animal. The virulence profile of the strains was assessed through biofilm formation, as well as serum resistance abilities. EnPEC and UPEC strains from the same animal exhibited slight variations in their virulence and antimicrobial resistance capabilities. Overall, most of the strain pairs showed a high similarity in their ability to establish biofilms and survive in serum complement activity.CONCLUSIONS:Overall, strains of E. coli isolated from both pyometra and cystitis in the same animal, despite presenting distinct clinical diseases, exhibit a wide phenotypic similarity, suggesting a common origin for the strains.

Escherichia coli (E. coli) are widely related to pyometra and cystitis in dogs, and these infections can occur simultaneously. The goal of this study was to determine genetic and pathogenic insights of 14 E. coli isolated simultaneously from pyometra content and bladder urine of seven bitches. To achieve this, in silico and in vitro comparative analyses were conducted. Whole-genome comparisons demonstrated that E. coli isolated from pyometra and urine of the same animal were predominantly genetic extraintestinal E. coli clones belonging to the same Sequence Type and phylogroup. The E. coli clones identified in this study included ST372, ST457, ST12, ST127, ST646, and ST961. Five isolates (35.7%) belonged to the ST12 complex. Except for two E. coli, all other isolates belonged to the B2 Clermont phylogroup. Interestingly, some genomes of E. coli from urine carried more virulence genes than those E. coli from pyometra. Both pyometra and urine E. coli isolates demonstrated a strong affinity for adhering to HeLa and T24 cells, with a low affinity for invading them. However, certain isolates from urine exhibited a greater tendency to adhere to T24 cells in qualitative and quantitative assays compared to isolates from pyometra. In conclusion, this study revealed the high genomic similarity between pyometra and urine E. coli isolates, as well as the virulent capacity of both to colonize endometrial and urothelial cells. The findings of this study underscore the importance of concurrently managing both infections clinically and could potentially contribute to future resources for the prevention of cystitis and pyometra.

Bovine genital campylobacteriosis (BGC) is a leading cause of return to estrus in cows. The etiologic agent, Campylobacter fetus subsp. venerealis (Cfv) is transmitted by venereal route. Hence, the surrounding reproductive tract microenvironment could play a role in return to estrus in cows. The presence of Cfv in cervicovaginal mucus of Angus breed females provide three experimental groups, which were subject to bacteriome analyses: 10 Cfv-positive cows (CVP), 10 Cfv-negative cows (CVN), and 10 nonsexually active heifers (NSA). Cows with return to estrus showed higher bacterial richness than NSA. Beta diversity analysis showed a significant difference (P = 0.006) in bacterial composition among the three groups analyzed (CVP, CVN, and NSA). However, no significant difference was found when comparing the CVP versus CVN groups. Ureaplasma and Pseudomonas were the genera most frequently observed in NSA, being Ureaplasma the predictor genus to that group, whereas Alistipes, Bacteroides, Rikenellaceae_RC9_gut_group, UCG-005, and UCG-10 were both significantly more abundant and predictors genera in cows with return to estrus. Our results provide an overview of the cervicovaginal bacterial microbiota in cows harboring Cfv and improve the knowledge of the pathogenesis of BGC.

Cattle farming is a major livestock activity with economic relevance in Rio Grande do Sul (RS), Brazil. However, this activity is still considered of intermediate to low technological level, and in this region, there are few epidemiologic reports of Campylobacter fetus subsp. venerealis (Cfv), the causative agent of bovine genital campylobacteriosis (BGC). Thus, we designed a cross-sectional study to assess the prevalence and Cfv-associated factors in cattle farms in RS, Brazil. In total, 99 farms were randomly selected to participate in the survey. Preputial mucus samples from selected bulls were collected twice (within a 15-day interval) and subjected to Cfv molecular detection. A farm was considered positive when at least one sample was positive for Cfv. Our findings indicate that the farm-level Cfv prevalence in RS is 67.67%. On average, the chance of a farm using natural service to be Cfv-positive increased approximately twice compared to farms that do not use natural service. We also determined that Cfv routine tests reduce the chance of a farm being positive by 92%. Therefore, both Cfv detection tests and the reduction of natural services decrease the chance of a farm being positive for Cfv. Finally, we conclude that Cfv is widely spread in Southern Brazil cattle farms and it is urgent the implementation of control measures to reduce Cfv prevalence in the target population.

SummaryEndometritis is recognised as one of the major causes of reproductive failure, specifically infertility and abortions, in mares. Infectious agents are the most common cause of endometritis, mainly bacteria. Here, we describe a case of an unexplained reproductive failure caused by an uncommon bacterium, A. hippocoleae, in a 15‐year‐old Thoroughbred mare with an oscillating reproductive history from Southern Brazil. Strain A. hippocoleae_LBV077/21 was isolated from the mare's uterus swab and identified by MALDI‐TOF (Matrix‐Assisted Laser Desorption Ionisation – Time of Flight) and 16 S rDNA sequencing. The antimicrobial susceptibility test showed that the strain was susceptible to ampicillin, ceftiofur, cephalexin, ciprofloxacin, rifampicin, penicillin, sulfamethoxazole/trimethoprim, tetracycline and vancomycin. Partial 16 S rDNA sequence phylogenetic analysis indicated a well‐supported position of A. hippocoleae_LBV077/21 in an exclusive clade of A. hippocoleae, whilst all other Arcanobacterium species were positioned in a separated clade, highlighting the lower syntenic relationship of the species A. hippocoleae to the other Arcanobacterium species. The present study reaffirms the importance of the isolation and identification of infectious agents in mares in cases of reproductive failure because uncommon agents can impede successful treatment and the improvement of reproductive failures.

Fungi have already been described as etiological agents of reproductive diseases such as endometritis and infertility in cows. However, few studies have been developed to elucidate the entire cervicovaginal fungal communities in cows. Therefore, our study aimed to characterize the fungal community present in the cervix of cows with different reproductive performances. Cervicovaginal mucus was collected from 36 Angus breed cows (1.5-12 years old) on a commercial beef cattle ranch. Twenty-one cows had a history of infertility in the year prior to the collection, showing early return to estrus. Ten cows were sampled at 60-70 days postpartum being considered fertile cows. Additionally, five non-sexually active heifers were employed as control group. Ascomycota and Basidiomycota were the predominant fungal phyla in the analyzed animals. Diversity metrics of the cervicovaginal fungal community revealed statistical differences in the composition of the fungal community among infertile cows, fertile cows and non-sexually active heifers. In addition, the cervicovaginal fungal microbiota had significative increased richness and evenness in nulliparous cows and non-sexually active heifers, while in multiparous cows a decreased richness and evenness of the fungal microbiota were identified. These results provide an unprecedented understanding of the cervicovaginal fungal structure associated with infertility and parity order.

Brucella canis is responsible for canine brucellosis, a neglected zoonotic disease. The omp25 gene has been described as an important marker for Brucella intra-species differentiation, in addition to the ability to interact with the host immune system. Therefore, this study investigated the omp25 sequence from B. canis strains associated to a phylogenetic characterization and the unveiling of the molecular structure. In vitro analyses comprised DNA extraction, PCR, and sequencing of omp25 from 19 B. canis strains. Moreover, in silico analyses were performed at nucleotide level for phylogenetic characterization and evolutionary history of B. canis omp25 gene; and in amino acid level including modeling, dynamics, and epitope prediction of B. canis Omp25 protein. Here, we identified a new mutation, L109P, which diverges the worldwide omp25 sequences in two large branches. Interestingly, this mutation appears to have epidemiology importance, based on a geographical distribution of B. canis strains. Structural and molecular dynamics analyses of Omp25 revealed that Omp25L109P does not sustain its native β-barrel. Likewise, the conformation of B-cell epitope on the mutated region was changed in Omp25L109P protein. Even without an evolutive marker, the new identified mutation appears to affect the basic function of B. canis Omp25 protein, which could indicate virulence adaptation for some B. canis strains in a context of geographical disposition.

Non-lactose-fermenting Escherichia coli (NLFEC) has a few descriptive studies restricted to human infections. In the present study, isolates of NLFEC obtained from urine samples of dogs with hyperadrenocorticism were characterized regarding their virulence ability, biofilm formation capacity and antimicrobial susceptibility profile. Escherichia coli lactose-fermenting strains from urinary infection in dogs with the same conditions were analysed to provide comparisons. The non-lactose-fermenting E. coli strains were classified as belonging to clade I E. coli, whereas the lactose-fermenting strains were classified in phylogroup B2. All strains presented virulence markers to adhesion, iron acquisition, toxins, colicin and cytotoxin production, and biofilm regulation. Components of the extracellular matrix in addition to the in vitro biofilm formation ability were observed in the strains. Multidrug resistance (MDR) profiles were observed by in vitro susceptibility tests to all NLFEC strains. In summary, non-lactose-fermenting uropathogenic E. coli from dogs behaves similar to lactose-fermenting E. coli, exhibiting MDR profile, and pathogenic potential of promote animal infections.

Pyometra is a life-threatening infectious disease that frequently affects bitches and queens. Although histopathological patterns of pyometra have been extensively explored, the microbiological aspects, such as bacteria pathogenicity, have not been correlated to microscopy endometrial lesions so far. In this study, these two pathological aspects of pyometra were analysed and correlated. Uterus fragments and intrauterine content samples were collected from pets diagnosed with pyometra (30) and submitted to histopathology analysis and bacterial culture, respectively. The degree of endometrial histopathological lesions in pyometra cases were classified as mild, moderate and severe. Thirty different bacteria isolates were identified from intrauterine content culture. Escherichia coli (E. coli) was pure isolated in 57.7% and highly related to severe endometrial lesions. Immunohistochemistry assay revealed the adhesion and invasion of this bacteria agent to the injured endometrium. Virulence aspects of these E. coli strains were explored, demonstrating biofilm formation ability and a set of virulence genes in most isolates. These results support the adaptive genetic and phenotypic advantages of E. coli for uterus infection, and justify the high frequency of this agent involved in pyometra cases.

Endometrial pathogenic E. coli (EnPEC) isolates are involved in endometrial infections in animals and humans. Besides the high aggressiveness of the endometrial infections, the EnPEC virulence profile and pathogenesis are still little known. In this study, we have sequenced and analyzed an EnPEC strain from canine pyometra (E. coli_LBV005/17), following a molecular characterization of the virulence profile and phylogenetic evolution of an EnPEC collection from canines and felines (45 strains). Most of the strains belonged to phylo-group B2, and display a high virulence profile. In particular we highlight the classification of the E. coli_LBV005/17 as sequence type 131 (ST131), in addition to other five strains, as observed by gyrB phylogenetic analysis. Also, the phylogenetic position of EnPEC strains from pyometra in companion animals suggests that their origins are from both extraintestinal and commensal E. coli strains. Accordingly to Principal Coordinates Analysis (PCoA) and phylogenetic analysis we can propose that EnPEC strains have neither the same genetic profile, nor a unique common ancestral. In summary, the present work characterize an EnPEC genome from bitch pyometra and the genetic profile of 45 EnPEC strains from companion animals pyometra, being the commonest virulence pattern: fimA, papC, hlyA, hlyE, cnf1, entB, iroN, irp1, bssS, bssR, and hmsP. These data improving the background knowledge of this E. coli pathotype related to pyometra in companion animals and may support new methods to prevent the disease evolution.

Long transportation times remain a challenge to the satisfactory diagnosis of Campylobacter fetus subsp. venerealis (Cfv). Here we demonstrated that samples of frozen bovine preputial mucus maintained at -20 degrees C for 10 days can be used as an alternative source for molecular diagnosis of Cfv. This approach will improve the analysis of this bacterium.