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Frontiers in Immunology 2022() is a commensal and an opportunistic pathogen of animals. This organism can cause inflammatory diseases, such as pneumonia, mastitis and endometritis in hosts....
() is a commensal and an opportunistic pathogen of animals. This organism can cause inflammatory diseases, such as pneumonia, mastitis and endometritis in hosts. However, the molecular basis for the pro-inflammatory properties of this organism is still largely unknown. In the current study, using murine macrophages as model, the ability of to induce pyroptosis was first determined. Then, pyolysin (PLO), a cholesterol-dependent cytolysin secreted by , was found to be closely related to -induced pyroptosis. Next, our work showed that PLO can form pores in the cell membrane, leading to the efflux of potassium (K), NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated caspase-1 activation, and gasdermin D (GSDMD) cleavage. Inhibition of the K/NLRP3/caspase-1/GSDMD pathway abolished and PLO-induced IL-1β release. Taken together, these results indicate -induced inflammation is related to PLO-induced pyroptosis and IL-1β release. Our work shed light on the pathogenesis of and the interaction between and hosts' immune system.
Topics: Animals; Bacterial Proteins; Bacterial Toxins; Caspase 1; Female; Hemolysin Proteins; Macrophages; Mice; NLR Family, Pyrin Domain-Containing 3 Protein; Potassium; Pyroptosis
PubMed: 35371034
DOI: 10.3389/fimmu.2022.832458 -
Revista Argentina de Microbiologia 2020We report the case of a twenty-year-old immunocompetent male patient presenting to the emergency room with pharyngitis and fever. Blood cultures were drawn and...
We report the case of a twenty-year-old immunocompetent male patient presenting to the emergency room with pharyngitis and fever. Blood cultures were drawn and Arcanobacterium haemolyticum (rough biotype) was recovered. The presence of the arcanolysin gene was investigated at the molecular level and the upstream region was amplified and sequenced in order to correlate it with the smooth or rough biotype. Although the isolate was susceptible to penicillin, vancomycin and gentamicin, empirical treatments first with amoxicillin/clavulanic acid (1g/12h) and then with ceftriaxone (1g/12h) failed and the infection evolved to sepsis. Finally, treatment with vancomycin (1g/12h) plus piperacillin/tazobactam (4.5g/8h) was effective. Lemierre's syndrome was ruled out. To the best of our knowledge, this is the first case of bacteremia by A. haemolyticum reported in Argentina.
Topics: Actinomycetales Infections; Adult; Arcanobacterium; Bacteremia; Humans; Male; Sepsis; Young Adult
PubMed: 32201068
DOI: 10.1016/j.ram.2020.01.001 -
Canadian Journal of Veterinary Research... Apr 2015Pododermatitis is a disease of concern for mink breeders in Canada and worldwide, as it causes discomfort and lowers the breeding rates on farms affected by the disease....
Pododermatitis is a disease of concern for mink breeders in Canada and worldwide, as it causes discomfort and lowers the breeding rates on farms affected by the disease. Unfortunately, the etiology and pathogenesis of pododermatitis are still unknown. In this study, we compared Staphylococcus spp. and Streptococcus canis isolates from healthy mink with isolates from animals with pododermatitis on 2 farms in Ontario. Almost all hemolytic Staphylococcus spp. isolated were shown to be Staphylococcus delphini Group A by 16S ribosomal ribonucleic acid (rRNA) sequence analysis and polymerase chain reaction (PCR). Pulsed-field gel electrophoresis (PFGE) did not reveal any S. delphini or S. canis clonal lineages specifically associated with pododermatitis, which suggests that these bacteria do not act as primary pathogens, but does not dismiss their potential roles as opportunistic pathogens. While S. delphini and S. canis were the most prevalent bacterial pathogens in mink pododermatitis, they were also present in samples from healthy mink. Arcanobacterium phocae is occasionally isolated from pododermatitis cases, but is difficult to recover with conventional culture methods due to its slow growth. A quantitative real-time PCR was developed for the detection of A. phocae and was tested on 138 samples of footpad tissues from 14 farms. The bacterium was detected only in pododermatitis-endemic farms in Canada and was at higher concentrations in tissues from infected footpads than in healthy tissues. This finding suggests that A. phocae is involved in the pathogenesis of pododermatitis.
Topics: Actinomycetales Infections; Animals; Arcanobacterium; Canada; Foot Diseases; Mink; RNA, Bacterial; RNA, Ribosomal, 16S; Real-Time Polymerase Chain Reaction; Skin Diseases, Bacterial; Staphylococcal Skin Infections; Staphylococcus; Streptococcal Infections; Streptococcus
PubMed: 25852228
DOI: No ID Found -
Journal of Veterinary Diagnostic... May 2018Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals including humans. Data on phenotypic and genotypic properties of T....
Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals including humans. Data on phenotypic and genotypic properties of T. pyogenes isolated from ruminants, particularly goats and sheep, are lacking. We characterized, by phenotypic and genotypic means, T. pyogenes of caprine and ovine origin, and established their phylogenetic relationship with isolates from other ruminants. T. pyogenes isolates ( n = 50) from diagnostic specimens of bovine ( n = 25), caprine ( n = 19), and ovine ( n = 6) origin were analyzed. Overall, variable biochemical activities were observed among the T. pyogenes isolates. The fimbriae-encoding gene, fimE, and neuraminidase-encoding gene, nanH, were, respectively, more frequently detected in the large ( p = 0.0006) and small ( p = 0.0001) ruminant isolates. Moreover, genotype V ( plo/ nanH/ nanP/ fimA/ fimC) was only detected in the caprine and ovine isolates, whereas genotype IX ( plo/ nanP/ fimA/ fimC/ fimE) was solely present in the isolates of bovine origin ( p = 0.0223). The 16S rRNA gene sequences of all T. pyogenes isolates were clustered with the reference T. pyogenes strain ATCC 19411 and displayed a high degree of identity to each other. Our results highlight phenotypic and genotypic diversity among ruminant isolates of T. pyogenes and reinforce the importance of characterization of more clinical isolates to better understand the pathogenesis of this bacterium in different animal species.
Topics: Actinomycetales Infections; Animals; Arcanobacterium; Cattle; Cattle Diseases; Genotype; Goat Diseases; Goats; Phylogeny; RNA, Ribosomal, 16S; Sheep; Sheep Diseases; Virulence Factors
PubMed: 29528808
DOI: 10.1177/1040638718762479 -
Genome Biology and Evolution Sep 2014The family Actinomycetaceae comprises several important pathogens that impose serious threat to human health and cause substantial infections of economically important...
The family Actinomycetaceae comprises several important pathogens that impose serious threat to human health and cause substantial infections of economically important animals. However, the phylogeny and evolutionary dynamic of this family are poorly characterized. Here, we provide detailed description of the genome characteristics of Trueperella pyogenes, a prevalent opportunistic bacterium that belongs to the family Actinomycetaceae, and the results of comparative genomics analyses suggested that T. pyogenes was a more versatile pathogen than Arcanobacterium haemolyticum in adapting various environments. We then performed phylogenetic analyses at the genomic level and showed that, on the whole, the established members of the family Actinomycetaceae were clearly separated with high bootstrap values but confused with the dominant genus Actinomyces, because the species of genus Actinomyces were divided into three main groups with different G+C content. Although T. pyogenes and A. haemolyticum were found to share the same branch as previously determined, our results of single nucleotide polymorphism tree and genome clustering as well as predicted intercellular metabolic analyses provide evidence that they are phylogenetic neighbors. Finally, we found that the gene gain/loss events occurring in each species may play an important role during the evolution of Actinomycetaceae from free-living to a specific lifestyle.
Topics: Actinomycetaceae; Biological Evolution; Phylogeny
PubMed: 25245410
DOI: 10.1093/gbe/evu211 -
Medicine Nov 2015Bloodstream infection (BSI) is an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the... (Observational Study)
Observational Study
Prevalence of Resistant Gram-Negative Bacilli in Bloodstream Infection in Febrile Neutropenia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Single Center Retrospective Cohort Study.
Bloodstream infection (BSI) is an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the causative bacteria and identify risk factors for BSI associated mortality in febrile neutropenia patients undergoing HSCT, we collected the clinical and microbiological data from patients underwent HSCT between 2008 and 2014 and performed a retrospective analysis. Throughout the study period, among 348 episodes of neutropenic fever in patients underwent HSCT, 89 episodes in 85 patients had microbiological defined BSI with a total of 108 isolates. Gram-negative bacteria (GNB) were the most common isolates (76, 70.3%) followed by gram-positive bacteria (GPB, 29, 26.9%) and fungus (3, 2.8%). As to the drug resistance, 26 multiple drug resistance (MDR) isolates were identified. Resistant isolates (n = 23) were more common documented in GNB, mostly Escherichia coli (9/36, 25%) and Klebsiella pneumonia (6/24, 25%). A total of 12 isolated were resistant to carbapenem including 4 K pneumoniae (4/24, 16.7%), 3 Stenotrophomonas maltophilia, and 1 Pseudomonas aeruginosa and other 4 GNB isolates (Citrobacter freumdii, Pseudomonas stutzeri, Acinetobacter baumanii, and Chryseobacterium indologenes). As to the GPB, only 3 resistant isolates were documented including 2 methicillin-resistant isolates (Staphylococcus hominis and Arcanobacterium hemolysis) and 1 vancomycin-resistant Enterococcus faecium. Among these 85 patients with documented BSI, 11 patients died of BSI as primary or associated cause with a BSI-related mortality of 13.1 ± 3.7% and 90-day overall survival after transplantation at 80.0 ± 4.3%. Patients with high-risk disease undergoing allo-HSCT, prolonged neutropenia (≥15 days) and infection with carbapenem-resistant GNB were associated with BSI associated mortality in univariate and multivariate analyses. Our report revealed a prevalence of GNB in BSI of neutropenic patients undergoing HSCT. Patients with high-risk diseases with prolonged neutropenia and carbapenem-resistant GNB were independent risk factors for BSI-related mortality.
Topics: Adolescent; Adult; Bacteremia; Drug Resistance, Bacterial; Febrile Neutropenia; Female; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Outcome Assessment, Health Care; Retrospective Studies; Young Adult
PubMed: 26559260
DOI: 10.1097/MD.0000000000001931 -
Folia Microbiologica Apr 2022In the present study, a single Arcanobacterium (A.) pinnipediorum strain isolated from discharge of a jaw swelling of a grey seal pup (Halichoerus grypus) in England,...
In the present study, a single Arcanobacterium (A.) pinnipediorum strain isolated from discharge of a jaw swelling of a grey seal pup (Halichoerus grypus) in England, UK, was identified. This strain was further characterized by phenotypical investigations, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), by Fourier transform infrared spectroscopy (FT-IR), and genotypically by sequencing the 16S rRNA gene and the genes gap encoding glyceraldehyde 3-phosphate dehydrogenase, tuf encoding elongation factor tu, and rpoB encoding the β subunit of bacterial RNA polymerase. The present study gives a first detailed characterization of the species A. pinnipediorum from a grey seal in the UK. However, the route of infection of the grey seal with the bacterial pathogen remains unclear.
Topics: Animals; Arcanobacterium; RNA, Ribosomal, 16S; Seals, Earless; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spectroscopy, Fourier Transform Infrared; United Kingdom
PubMed: 34825291
DOI: 10.1007/s12223-021-00932-7 -
IDCases 2021is an extremely rare cause of cerebral abscess. We present a unique case of sinusitis complicated by preseptal cellulitis and cerebral abscess. The patient initially...
is an extremely rare cause of cerebral abscess. We present a unique case of sinusitis complicated by preseptal cellulitis and cerebral abscess. The patient initially presented with pharyngitis and then developed sinus congestion, headache and facial pain. Computed tomography and magnetic resonance imaging revealed a right gyrus rectus cerebral abscess and paranasal sinus infection. The patient underwent endoscopic sinus surgery and cultures revealed . Repeat imaging revealed maturation and progression of intracranial abscess. The abscess was drained and patient was treated with parenteral and oral antibiotics until complete clinical and radiological remission. This case highlights the importance of recognizing as a cause of invasive disease in immunocompetent hosts.
PubMed: 33304814
DOI: 10.1016/j.idcr.2020.e01014 -
Microbial Genomics May 2024Cutaneous ulcers are common in yaws-endemic areas. Although often attributed to ' subsp. and , quantitative PCR has highlighted a significant proportion of these ulcers...
Using 16s rRNA sequencing to characterize the microbiome of tropical cutaneous ulcer disease: insights into the microbial landscape and implications for diagnosis and treatment.
Cutaneous ulcers are common in yaws-endemic areas. Although often attributed to ' subsp. and , quantitative PCR has highlighted a significant proportion of these ulcers are negative for both pathogens and are considered idiopathic. This is a retrospective analysis utilising existing 16S rRNA sequencing data from two independent yaws studies that took place in Ghana and the Solomon Islands. We characterized bacterial diversity in 38 samples to identify potential causative agents for idiopathic cutaneous ulcers. We identified a diverse bacterial profile, including , , , spp and , consistent with findings from previous cutaneous ulcer microbiome studies. No single bacterial species was universally present across all samples. The most prevalent bacterium, , appeared in 42% of samples, suggesting a multifactorial aetiology for cutaneous ulcers in yaws-endemic areas. This study emphasizes the need for a nuanced understanding of potential causative agents. The findings prompt further exploration into the intricate microbial interactions contributing to idiopathic yaw-like ulcers, guiding future research toward comprehensive diagnostic and therapeutic strategies.
Topics: Humans; RNA, Ribosomal, 16S; Microbiota; Skin Ulcer; Ghana; Male; Yaws; Retrospective Studies; Female; Adult; Bacteria; Melanesia; Middle Aged; Staphylococcus; Streptococcus pyogenes; Arcanobacterium; Campylobacter
PubMed: 38739120
DOI: 10.1099/mgen.0.001234 -
Internal Medicine (Tokyo, Japan) Jun 2019An 81-year-old Japanese man with no history of diabetes mellitus was admitted to our hospital for a fever with a new ulcerative lesion on the left heel. Blood cultures... (Review)
Review
An 81-year-old Japanese man with no history of diabetes mellitus was admitted to our hospital for a fever with a new ulcerative lesion on the left heel. Blood cultures on admission grew Arcanobacterium haemolyticum in aerobic bottles. He was therefore diagnosed with A. haemolyticum bacteremia and osteomyelitis complicated with foot decubitus ulcer. He was successfully treated with intravenous antibiotic therapy and debridement of the left heel. Our case and literature review show that it is important to recognize that A. haemolyticum is a systemic causative pathogen in immunocompetent patients in primary care practice.
Topics: Actinomycetales Infections; Aged, 80 and over; Anti-Bacterial Agents; Arcanobacterium; Bacteremia; Combined Modality Therapy; Debridement; Education, Medical, Continuing; Fever; Foot Ulcer; Humans; Male; Microbial Sensitivity Tests; Osteomyelitis; Physicians, Primary Care; Pressure Ulcer
PubMed: 30713320
DOI: 10.2169/internalmedicine.2162-18