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Frontiers in Microbiology 2023is a zoonotic agent that causes severe invasive diseases in domestic animals and humans, but little is known about its pathogenesis and virulence mechanisms so far....
is a zoonotic agent that causes severe invasive diseases in domestic animals and humans, but little is known about its pathogenesis and virulence mechanisms so far. SCM, the M-like protein expressed by , is considered one of the major virulence determinants. Here, we report on the two distinct groups of SCM. SCM-1 proteins were already described to interact with its ligands IgG and plasminogen as well as with itself and confer antiphagocytic capability of SCM-1 expressing bacterial isolates. In contrast, the function of SCM-2 type remained unclear to date. Using whole-genome sequencing and subsequent bioinformatics, FACS analysis, fluorescence microscopy and surface plasmon resonance spectrometry, we demonstrate that, although different in amino acid sequence, a selection of diverse SCM-2-type isolates, phylogenetically representing the full breadth of SCM-2 sequences, were able to bind fibrinogen. Using targeted mutagenesis of an SCM-2 isolate, we further demonstrated that this strain was significantly less able to survive in canine blood. With respect to similar studies showing a correlation between fibrinogen binding and survival in whole blood, we hypothesize that SCM-2 has an important contribution to the pathogenesis of in the host.
PubMed: 37965557
DOI: 10.3389/fmicb.2023.1228472 -
Theriogenology Aug 2024The vaginal microbiota of the queen (i.e., female cat) has never been described using culture independent methods. The objectives of the present research were to...
The vaginal microbiota of the queen (i.e., female cat) has never been described using culture independent methods. The objectives of the present research were to describe the vaginal microbiota of healthy domestic shorthair queens using both 16S rRNA sequencing and culture, and to assess the effects of age, living environment, and reproductive season on its composition. Thirty queens undergoing elective ovariectomy were included in the study. The vaginal samples were collected just before surgery, from animals under general anaesthesia. Two consecutive mini-swabs were introduced in the queens' vaginal tract. A preliminary study with 10 healthy queens aimed to negate sampling order's effect. Two consecutive samples for sequencing (5 queens, 10 swabs) and culture (5 queens, 10 swabs) were collected, confirming a match (100 % in culture, Bray-Curtis P = 0.96 in sequencing). The experiment included 20 queens that were prospectively grouped based on age (prepubertal N = 10, adult N = 10), living environment (indoor N = 10, outdoor N = 10), and time of the year, whether during the reproductive season (N = 10) or during seasonal anoestrous (N = 10). Bacteria were identified through metataxonomic analysis, amplifying the V1-V2 regions of 16S rRNA gene, and through standard culture followed by MALDI-TOF MS. The feline vaginal microbiota is dominated by Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteria. Escherichia-Shigella, Streptococcus, and Pasteurella were the most abundant genera. Although culture underestimated bacterial richness and diversity compared to sequencing, Escherichia and Streptococcus were the most isolated bacteria. No bacterial growth was observed in 15 % of samples (N = 3/20), whereas growth of one or two bacterial species was observed in 64.7 % (N = 11/17) and 35.3 % (N = 6/17) of cases, respectively. No differences in terms of alpha (Kruskal-Wallis rank sum test P = 0.65) and beta diversity (Bray-Curtis, Unweighted and Weighted UniFrac analyses P > 0.5) were observed. Although a difference in alpha diversity based on phylogenetic tree (P = 0.02) was detected between indoor and outdoor queens. In conclusion, mixed and monoculture of Escherichia coli, Streptococcus canis, Staphylococcus felis, and Enterococcus spp. are normal findings within the cat vagina. Age and reproductive season do not influence the feline vaginal microbiota, whereas further research is needed to elucidate the role of the living environment.
Topics: Animals; Cats; Female; Vagina; Microbiota; Bacteria; RNA, Ribosomal, 16S; Seasons
PubMed: 38772246
DOI: 10.1016/j.theriogenology.2024.05.021 -
Journal of Comparative Pathology May 2024This case series describes the post-mortem findings in 17 bitches (Canis lupus familiaris) with a recent (<7 days) history of caesarean section, most (94%) of which had...
This case series describes the post-mortem findings in 17 bitches (Canis lupus familiaris) with a recent (<7 days) history of caesarean section, most (94%) of which had undergone conservative caesarean section with preservation of the uterus. Brachycephalic breeds accounted for 71% of all cases, with the French Bulldog (35%, n = 6), English Bulldog (18%, n = 3) and Boston Terrier (12%, n = 2) overrepresented. Eleven animals (65%) died between 4 and 48 h after surgery, whereas six (35%) died during the procedure. The most common cause of death was septicaemia (41%, n = 7) associated with Streptococcus canis (29%, n = 5) and/or Escherichia coli (24%, n = 4). Other causes of death included brachycephalic obstructive airway syndrome (BOAS)-associated respiratory failure (24%, n = 4), haemorrhagic shock (18%, n = 3), inconclusive (12%, n = 2) and gastric dilatation and volvulus (6%, n = 1). Histopathological changes were seen in the uterus of 10 cases and included marked inflammation (60%, n = 6), marked haemorrhage (20%, n = 2) or both (20%, n = 2). Metritis was often characterized by fibrinonecrotic, neutrophilic to mixed inflammation, consistent with acute infection. However, prominent lymphohistiocytic infiltrates in two cases suggested that infection had been present prior to surgery. Peritonitis, myositis and panniculitis commonly (35%, n = 6) surrounded the incision sites. The presence of inflammation and bacterial colonies within multiple surgical sites suggested iatrogenic implantation of bacteria, potentially from the uterine lumen. Bacterial culture and isolation, as well as tape measurements for evaluation of conformational BOAS risk factors where applicable, are recommended as part of the routine post-mortem work-up for bitches that die shortly after caesarean section.
Topics: Animals; Female; Dogs; Dog Diseases; Cesarean Section; Pregnancy
PubMed: 38636281
DOI: 10.1016/j.jcpa.2024.03.205 -
Journal of Dairy Science Dec 2023The early detection of major mastitis pathogens is crucial for the udder health management of dairy herds. Testing of pooled milk samples, either individual test-day cow...
Estimation of the performance of two real-time polymerase chain reaction assays for detection of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in pooled milk samples in a field study.
The early detection of major mastitis pathogens is crucial for the udder health management of dairy herds. Testing of pooled milk samples, either individual test-day cow samples (TDCS) or aseptically collected pre-milk quarter samples (PMQS) may provide an easy to use and cost-effective group level screening tool. Therefore, the aim of this study was (1) to evaluate the sensitivity (Se) and specificity (Sp) of 2 commercial multiplex real-time PCR test kits applied to pooled milk samples using a Bayesian latent class analysis and (2) to estimate the probability of detection in relation to the pool size and the number of cows positively tested by bacteriological culture (BC) within a pool. Pools of 10, 20 and 50 cows were assembled from 1,912 test-day samples and 7,336 PMQS collected from a total of 2,045 cows from 2 commercial dairy farms. Two commercial quantitative real-time PCR kits were applied to detect Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in the pooled samples, and a BC was applied to PMQS yielding a cumulative pool result. A pool was considered BC-positive if it contained at least one BC-positive PMQS. Pathogens were more frequently detected in the PMQS pools than in the TDCS pools. Pools of 10 cows showed the highest probability of detection irrespective of sample type or type of PCR kit compared with larger pool sizes. Estimation with a Bayesian latent class analysis resulted in a median Se in PMQS pools of 10 cows for Staph. aureus of 63.3% for PCR kit I, 78.1% for PCR kit II, and 95.5% for BC; the Sp values were 97.0%, 97.6%, and 89.1%, respectively. The estimated median Se for Strep. species for PCR kits ranged between 77.5 and 85.6% and for BC between 73.7% and 79.2%; the median Sp values ranged between 93.6 and 99.2% for PCR kits, and between 96.9% and 97.4% for BC. In addition, the probability of detection increased with an increasing number of BC-positive cows per pool. To achieve a probability of detection of 90%, the estimated number of positive cows in PMQS pools of 10 cows for kit I was 4.1 for Staph. aureus, 1.5 for Strep. agalactiae, and 1.3 for Strep. dysgalactiae; for the equivalent TDCS pools and pathogens, 6.9, 1.9, and 2.0 positive cows were required, respectively. For Kit II and PMQS pools, the number of positive cows required was 2.8 for Staph. aureus, 1.4 for Strep. agalactiae, and 1.2 for Strep. dysgalactiae; for the equivalent TDCS pools and pathogens, 5.3, 1.8, and 2.0 positive cows were required, respectively. In conclusion, the type of samples used for pooling, the pool size and the number of infected cows per pool determine the probability of detecting an infection with major mastitis pathogens within a pool by PCR testing.
Topics: Female; Animals; Cattle; Streptococcus agalactiae; Real-Time Polymerase Chain Reaction; Milk; Staphylococcus aureus; Bayes Theorem; Mastitis, Bovine; Streptococcal Infections; Staphylococcal Infections; Cattle Diseases
PubMed: 37641275
DOI: 10.3168/jds.2022-21902 -
Cureus Apr 2024Prosthetic joint infections (PJIs) are one of the most feared complications by orthopaedic surgeons. Haematogenous PJI represents an important part of PJI cases. is an...
Prosthetic joint infections (PJIs) are one of the most feared complications by orthopaedic surgeons. Haematogenous PJI represents an important part of PJI cases. is an extremely rare cause of haematogenous PJI and its medical and surgical treatment and prognosis are not well established. We present a 79-year-old female patient who had a revision total knee arthroplasty (rTKA) surgery three years before. She was admitted to the hospital referring to three days of knee pain, restricted range of motion, and fever. Blood tests demonstrated leukocyte and C-reactive protein elevation. Joint fluid aspiration showed elevated white blood cell count with a high neutrophil differential and its conventional culture was positive for . She did not have pets but she took care of her daughter's dog. An acute haematogenous infection of the rTKA was diagnosed and treated with debridement, antibiotics (eight weeks of IV ceftriaxone), and implant retention (DAIR). After one year, the patient remains clinically asymptomatic without changes on X-rays and with normal serum levels of inflammatory blood markers. has to be kept in mind as a possible cause of haematogenous TKA infection in patients who have contact with domestic pets and patients should be asked for this contact. We recommend DAIR as a viable treatment option for this type of infection, which may show excellent results.
PubMed: 38745789
DOI: 10.7759/cureus.58247 -
Animals : An Open Access Journal From... Jul 2023Studies of microbiota in normal canine milk from healthy dams are sparse. As is the case with blood and urine, it was considered that milk contains no microbiota. Any...
Studies of microbiota in normal canine milk from healthy dams are sparse. As is the case with blood and urine, it was considered that milk contains no microbiota. Any discovery of bacteria in canine milk is, therefore, often noted to be a result of contamination during sampling or interpreted as mastitis and treated with antibiotics. Milk was collected twice within 19 days after natural parturition from 11 lactating dams, with no general or local clinical signs of mastitis or other disease. The skin and teats were prepared with an antimicrobial protocol prior to each milk sampling. In total, 210 milk samples were collected and assessed for a number of bacterial colonies grown on each plate. Bacterial growth was detected in 180 samples (86%). , spp., spp., Coagulase-Negative Staphylococci (CoNS), spp., , spp., spp., and were identified from pure and/or mixed bacterial growth, listed in descending order of occurrence. Despite the small sample size, the consistent occurrence of bacteria in early postpartum dams indicates a genuine occurrence of bacteria in canine milk, rather than random contamination. The finding of bacteria in the milk of dams should not, therefore, be the sole argument for the diagnosis of mastitis.
PubMed: 37444004
DOI: 10.3390/ani13132206 -
BMC Research Notes May 2024The purpose of this study was to identify the M protein trans-acting positive regulator (Mga) orthologue and its adjacent M-like protein (SCM) alleles in Streptococcus...
OBJECTIVE
The purpose of this study was to identify the M protein trans-acting positive regulator (Mga) orthologue and its adjacent M-like protein (SCM) alleles in Streptococcus canis.
RESULTS
Using the 39 SCM allele isolates and polymerase chain reaction-based amplification and sequencing, we obtained the deduced Mga amino acid (AA) sequences. The 22 Mga sequences in whole-genome sequences were obtained by searching the National Collection of Type Cultures 12,191(T) Mga sequence into the database. The percentage identity to the type-strain Mga sequence was examined along with its size. The presence of the Mga-specific motifs was confirmed. Of the 62 strains, we identified 59 Mga sequences with an AA size of 509 (except for four different sizes). Percentage identity ranged from 96.66 to 100% with the confirmed Mga-specific motifs and diverse SCM allele populations. Our findings support the presence of an Mga orthologue and diverse SCM allele populations.
Topics: Alleles; Streptococcus; Bacterial Proteins; Amino Acid Sequence
PubMed: 38750516
DOI: 10.1186/s13104-024-06795-8 -
Journal of Veterinary Science Sep 2023Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the surface of , coded with gapC, is a glycolytic enzyme that was reported to be a moonlighting protein and virulence...
BACKGROUND
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the surface of , coded with gapC, is a glycolytic enzyme that was reported to be a moonlighting protein and virulence factor.
OBJECTIVE
This study assessed GAPDH as a potential immunization candidate protein to prevent streptococcus infections.
METHODS
Mice were vaccinated subcutaneously with recombinant GAPDH and challenged with . They were then evaluated using histological methods. rGAPDH of mouse bone marrow-derived dendritic cells (BMDCs) was evaluated using immunoblotting, reverse transcription quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay methods.
RESULTS
Vaccination with rGAPDH improved the survival rates and decreased the bacterial burdens in the mammary glands compared to the control group. The mechanism by which rGAPDH vaccination protects against was investigated. experiments showed that rGAPDH boosted the generation of interleukin-10 and tumor necrosis factor-α. Treatment of BMDCs with TAK-242, a toll-like receptor 4 inhibitor, or C29, a toll-like receptor 2 inhibitor, reduced cytokines substantially, suggesting that rGAPDH may be a potential ligand for both TLR2 and TLR4. Subsequent investigations showed that rGAPDH may activate the phosphorylation of MAPKs and nuclear factor-κB.
CONCLUSIONS
GAPDH is a promising immunization candidate protein for targeting virulence and enhancing immune-mediated protection. Further investigations are warranted to understand the mechanisms underlying the activation of BMDCs by rGAPDH in a TLR2- and TLR4-dependent manner and the regulation of inflammatory cytokines contributing to mastitis pathogenesis.
Topics: Female; Animals; Mice; Toll-Like Receptor 4; Toll-Like Receptor 2; Streptococcus; Glyceraldehyde-3-Phosphate Dehydrogenases; Cytokines; Immunity, Innate; Immunologic Factors; Vaccines
PubMed: 38031651
DOI: 10.4142/jvs.23103 -
Journal of Veterinary Science Sep 2023Leopard cat () is a small wild cat assessed as an endangered wildlife in Korea. There have been very few reports of their diseases. Herein, we describe fibrinous...
Leopard cat () is a small wild cat assessed as an endangered wildlife in Korea. There have been very few reports of their diseases. Herein, we describe fibrinous pleuritis caused by infection with excessive pleural effusion, hydropericardium, mild ascites, and liver fibrosis in a leopard cat. is a commensal microflora in domestic cats and often affects the upper respiratory tract inducing chronic and severe respiratory diseases. However, there is no literature regarding the in leopard cats. Therefore, we first report fibrinous pleuritis associated with an infection in a leopard cat.
Topics: Cats; Animals; Streptococcus; Animals, Wild; Pleurisy; Cat Diseases
PubMed: 38031647
DOI: 10.4142/jvs.23080 -
Frontiers in Veterinary Science 2023To investigate the antimicrobial effect of cold atmospheric plasma (CAP) on pathogens associated with canine bacterial keratitis.
PURPOSE
To investigate the antimicrobial effect of cold atmospheric plasma (CAP) on pathogens associated with canine bacterial keratitis.
MATERIALS AND METHODS
, , and strains, which were obtained from dogs with infectious keratitis, were subjected to testing. For each species, four isolates and a reference strain were cultivated on Columbia sheep blood agar and treated with the kiNPen Vet plasma pen from Neoplas GmbH, Greifswald, Germany. Various continuous treatment durations (0.5, 2, and 5 min) were applied, along with a 0.5-min treatment repeated four times at short intervals. These treatments were conducted at distances of 3 and 18 mm between the agar surface and the pen.
RESULTS
CAP treatment reduced bacterial growth in all three species. The most effective treatment duration was 5 min at 3 mm distance, resulting in inhibition zones ranging from 19 to 22 mm for , 26-45 mm for and an overall reduction of bacterial growth for . Inhibition zones were smaller with decreasing treatment duration and larger distance. Treatment times of 30 s repeated four times and 2 min showed comparable results. Treatment with argon alone did not lead to visible reduction of bacterial growth.
CONCLUSION
Argon cold atmospheric plasma demonstrated a potent antimicrobial effect on and strains with the latter showing the highest sensitivity.
PubMed: 38264471
DOI: 10.3389/fvets.2023.1320145