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The Pediatric Infectious Disease Journal Jan 2024
Topics: Child; Humans; Arcanobacterium; Actinomycetales Infections; Immunocompetence
PubMed: 37922488
DOI: 10.1097/INF.0000000000004147 -
Animals : An Open Access Journal From... Nov 2020Lactic acid bacteria (LAB) dominate human vaginal microbiota and inhibit pathogen proliferation. In other mammals, LAB do not dominate vaginal microbiota, however shifts...
Lactic acid bacteria (LAB) dominate human vaginal microbiota and inhibit pathogen proliferation. In other mammals, LAB do not dominate vaginal microbiota, however shifts of dominant microorganisms occur during ovarian cycle. The study objectives were to characterize equine vaginal microbiota in mares by culture-dependent and independent methods and to describe its variation in estrus and diestrus. Vaginal swabs from 8 healthy adult Arabian mares were obtained in estrus and diestrus. For culture-dependent processing, bacteria were isolated on Columbia blood agar (BA) and Man Rogosa Sharpe (MRS) agar. LAB comprised only 2% of total bacterial isolates and were not related to ovarian phases. For culture-independent processing, V3/V4 variable regions of the 16S ribosomal RNA gene were amplified and sequenced using Illumina Miseq. The diversity and composition of the vaginal microbiota did not change during the estrous cycle. Core equine vaginal microbiome consisted of Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria at the phylum level. At the genus level it was defined by , uncultured and . comprised only 0.18% of the taxonomic composition in estrus and 0.37% in diestrus. No differences in the relative abundance of the most abundant phylum or genera were observed between estrus and diestrus samples.
PubMed: 33153053
DOI: 10.3390/ani10112020 -
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 -
FASEB Journal : Official Publication of... Jun 2021Certain species of pathogenic bacteria damage tissues by secreting cholesterol-dependent cytolysins, which form pores in the plasma membranes of animal cells. However,...
Certain species of pathogenic bacteria damage tissues by secreting cholesterol-dependent cytolysins, which form pores in the plasma membranes of animal cells. However, reducing cholesterol protects cells against these cytolysins. As the first committed step of cholesterol biosynthesis is catalyzed by squalene synthase, we explored whether inhibiting this enzyme protected cells against cholesterol-dependent cytolysins. We first synthesized 22 different nitrogen-containing bisphosphonate molecules that were designed to inhibit squalene synthase. Squalene synthase inhibition was quantified using a cell-free enzyme assay, and validated by computer modeling of bisphosphonate molecules binding to squalene synthase. The bisphosphonates were then screened for their ability to protect HeLa cells against the damage caused by the cholesterol-dependent cytolysin, pyolysin. The most effective bisphosphonate reduced pyolysin-induced leakage of lactate dehydrogenase into cell supernatants by >80%, and reduced pyolysin-induced cytolysis from >75% to <25%. In addition, this bisphosphonate reduced pyolysin-induced leakage of potassium from cells, limited changes in the cytoskeleton, prevented mitogen-activated protein kinases cell stress responses, and reduced cellular cholesterol. The bisphosphonate also protected cells against another cholesterol-dependent cytolysin, streptolysin O, and protected lung epithelial cells and primary dermal fibroblasts against cytolysis. Our findings imply that treatment with bisphosphonates that inhibit squalene synthase might help protect tissues against pathogenic bacteria that secrete cholesterol-dependent cytolysins.
Topics: A549 Cells; Bacterial Proteins; Bacterial Toxins; Cell Proliferation; Cholesterol; Cytotoxins; Diphosphonates; Enzyme Inhibitors; Farnesyl-Diphosphate Farnesyltransferase; Fibroblasts; HeLa Cells; Hemolysin Proteins; Humans; Protective Agents; Streptolysins
PubMed: 33991130
DOI: 10.1096/fj.202100164R -
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 -
Veterinary Microbiology Apr 2020The present study was designed to identify nine Arcanobacterium phocae strains isolated from cases of mink dermatitis of a single farm in Finland and characterize the...
The present study was designed to identify nine Arcanobacterium phocae strains isolated from cases of mink dermatitis of a single farm in Finland and characterize the strains for epidemiological relationships. All nine strains and previously described A. phocae used for comparative purposes were identified and further characterized phenotypically, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), by Fourier Transform Infrared Spectroscopy (FT-IR) and genotypically by detection of phocaelysin encoding gene phl with a previously developed loop-mediated isothermal amplification (LAMP) assay and by sequencing 16S rRNA gene and gene phl, the elongation factor tu encoding gene tuf and the β subunit of bacterial RNA polymerase encoding gene rpoB. Genetic relatedness among isolates was determined using whole-genome single nucleotide polymorphism (wgSNP) analysis. The wgSNP results, partly the MALDI-TOF MS and FT-IR analyses and sequencing of the genes, revealed that the nine A. phocae strains recovered from a single farm showed close sequence similarities among each other and differed from previously investigated A. phocae strains isolated from other farms and animals in Finland and from the A. phocae type strain. This indicated a close epidemiological relationship of the A. phocae strains isolated from a single farm and that the nine A. phocae strains of the present study might have developed from a common ancestor.
Topics: Actinomycetales Infections; Animals; Arcanobacterium; Dermatitis; Farms; Finland; Genome, Bacterial; Genotype; Mink; Phenotype; Phylogeny; Polymorphism, Single Nucleotide; RNA, Ribosomal, 16S; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spectroscopy, Fourier Transform Infrared
PubMed: 32273004
DOI: 10.1016/j.vetmic.2020.108618 -
Carbohydrate Polymers Feb 2021Vitexin of Ficus deltoidea exhibits intestinal α-glucosidase inhibitory and blood glucose lowering effects. This study designs oral intestinal-specific alginate...
Vitexin of Ficus deltoidea exhibits intestinal α-glucosidase inhibitory and blood glucose lowering effects. This study designs oral intestinal-specific alginate nanoparticulate system of vitexin. Nanospray-dried alginate, alginate/stearic acid and alginate-C18 conjugate nanoparticles were prepared. Stearic acid was adopted to hydrophobize the matrix and minimize premature vitexin release in stomach, whereas C-18 conjugate as immobilized fatty acid to sustain hydrophobic effect and drug release. Nanoparticles were compacted with polyethylene glycol (PEG 3000, 10,000 and 20,000). The physicochemical, drug release, in vivo blood glucose lowering and intestinal vitexin content of nanoparticles and compact were determined. Hydrophobization of alginate nanoparticles promoted premature vitexin release. Compaction of nanoparticles with PEG minimized vitexin release in the stomach, with stearic acid loaded nanoparticles exhibiting a higher vitexin release in the intestine. The introduction of stearic acid reduced vitexin-alginate interaction, conferred alginate-stearic acid mismatch, and dispersive stearic acid-induced particle breakdown with intestinal vitexin release. Use of PEG 10,000 in compaction brought about PEG-nanoparticles interaction that negated initial vitexin release. The PEG dissolution in intestinal phase subsequently enabled particle breakdown and vitexin release. The PEG compacted nanoparticles exhibited oral intestinal-specific vitexin release, with positive blood glucose lowering and enhanced intestinal vitexin content in vivo.
Topics: Administration, Oral; Alginates; Animals; Apigenin; Bacterial Proteins; Bacterial Toxins; Blood Glucose; Diabetes Mellitus, Experimental; Drug Carriers; Drug Liberation; Ficus; Glycoside Hydrolase Inhibitors; Hemolysin Proteins; Hydrogen Bonding; Hypoglycemic Agents; Male; Nanoparticles; Particle Size; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Stearic Acids; Streptozocin; alpha-Glucosidases
PubMed: 33357875
DOI: 10.1016/j.carbpol.2020.117312 -
Veterinary Microbiology Sep 2023Trueperella pyogenes (T. pyogenes) could cause zoonotic disease in various mammals, resulting in significant economic losses. Due to the lack of effective vaccine and...
Trueperella pyogenes (T. pyogenes) could cause zoonotic disease in various mammals, resulting in significant economic losses. Due to the lack of effective vaccine and the emergence of bacterial resistance, there is a big need for new and improved vaccines. In this study, the non-hemolytic pyolysin mutant (PLOW497F), fimbriae E (FimE) and a truncated cell wall protein (HtaA-2) were selected to generate single or multivalent protein vaccines and their efficacies against lethal T. pyogenes challenge were evaluated in a mouse model. The results showed that the levels of specific antibody were significantly higher than the PBS control group after the booster vaccination. Compared to PBS treated mice, vaccinated mice had upregulated expressions of the inflammatory cytokine genes after the first vaccination. There was a downward trend thereafter, but return to the similar or even higher levels after challenge. Furthermore, co-immunization with rFimE or rHtaA-2 could significantly enhance the anti-hemolysis antibodies induced by rPLOW497F. The supplement of rHtaA-2 induced higher agglutinating antibodies compared with single administration with rPLOW497F or rFimE. Apart from these, the pathological lesions of lung were alleviated in rHtaA-2, rPLOW497F or their combinations immunized mice. Notably, immunization with rPLOW497F, rHtaA-2, combinations of rPLOW497F and rHtaA-2 or rHtaA-2 and rFimE completely protected mice from challenge, whereas the PBS immunized mice could not survive past 1 day post challenge. Thus, PLOW497F and HtaA-2 might be useful in developing efficient vaccines to prevent T. pyogenes infection.
Topics: Animals; Mice; Bacterial Proteins; Bacterial Toxins; Hemolysin Proteins; Bacterial Vaccines; Mammals
PubMed: 37307768
DOI: 10.1016/j.vetmic.2023.109810