RESUMO
Staphylococcus haemolyticus (S. haemolyticus) is one of the most common coagulase-negative staphylococci (CoNS) isolates from bovine mastitis. Paeoniflorin (PF) shows anti-inflammatory effects on different inflammatory diseases in vitro studies and in vivo animal experiments. In this study, the viability of bovine mammary epithelial cells (bMECs) was detected by the cell counting kit-8 experiment. Subsequently, bMECs were induced with S. haemolyticus, and the induction dosage was determined. The expression of pro-inflammatory cytokines and toll-like receptor (TLR2) and nuclear factor kappa-B (NF-κB) signaling pathway-related genes were investigated by quantitative real-time PCR. The critical pathway proteins were detected by western blot. The results showed that the multiplicity of infection (MOI; the ratio of bacteria to bMECs) 5:1 of S. haemolyticus for 12 h could cause cellular inflammation, which was selected to establish the inflammatory model. Incubation with 50 µg/ml PF for 12 h was the best intervention condition for cells stimulated by S. hemolyticus. Quantitative real-time PCR and western blot analysis showed that PF inhibited the activation of TLR2 and NF-κB pathway-related genes and the expression of related proteins. Western blot results showed that PF suppressed the expression of NF-κB unit p65, NF-κB unit p50, and MyD88 in bMECs stimulated by S. haemolyticus. The inflammatory response pathway and molecular mechanism caused by S. haemolyticus on bMECs are related to TLR2-mediated NF-κB signaling pathways. The anti-inflammatory mechanism of PF may also be through this pathway. Therefore, PF is expected to develop potential drugs against CoNS-induced bovine mastitis.
Assuntos
Doenças dos Bovinos , Mastite Bovina , Feminino , Animais , Bovinos , NF-kappa B/metabolismo , Receptor 2 Toll-Like/genética , Staphylococcus haemolyticus/metabolismo , Mastite Bovina/microbiologia , Transdução de Sinais , Inflamação/veterinária , Receptores Toll-Like , Anti-Inflamatórios/farmacologia , Células Epiteliais/metabolismo , Glândulas Mamárias Animais/metabolismoRESUMO
Decabromodiphenyl ether (BDE-209) is a brominated flame retardant and a priority contaminant. Currently, little information is available about its significance in the environment, specifically about its susceptibility to aerobic biotransformation at low temperature. In this work, five phylogenetically diverse BDE-209-degrading bacterial strains were isolated from river sediments of northern China. These strains were distributed among four different genera-Acinetobacter, Pseudomonas, Bacillus and Staphylococcus. All five isolates were capable of growing on BDE-209, among which two isolates show better growth. By detailed morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis, the two strains were identified and named as Staphylococcus haemolyticus LY1 and Bacillus pumilus LY2. The two bacteria can grow in mineral salt medium containing BDE-209 substrate across the temperatures ranging from 2.5 to 35 °C, with an optimum temperature of 25 °C which could be considered as psychrotrophs accordingly. The degradation experiment showed that more than 70.6 and 85.5 % of 0.5 mg/L BDE-209 were degraded and the highest mineralization efficiencies of 29.8 and 39.2 % were achieved for 0.5 mg/L BDE-209 by S. haemolyticus LY1 and B. pumilus LY2, respectively. To the best of our knowledge, this is the first demonstration for the biodegradation of BDE-209 by two psychrotrophic bacteria isolated from environment.
Assuntos
Bacillus pumilus/metabolismo , Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/metabolismo , Staphylococcus haemolyticus/metabolismo , Acinetobacter/crescimento & desenvolvimento , Acinetobacter/isolamento & purificação , Acinetobacter/metabolismo , Bacillus pumilus/crescimento & desenvolvimento , Bacillus pumilus/isolamento & purificação , Biodegradação Ambiental , Biotransformação , China , DNA Ribossômico , Sedimentos Geológicos/microbiologia , Filogenia , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Rios/microbiologia , Staphylococcus haemolyticus/crescimento & desenvolvimento , Staphylococcus haemolyticus/isolamento & purificaçãoRESUMO
This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the
Assuntos
Animais , Farmacorresistência Bacteriana Múltipla/genética , Fermentação/fisiologia , Manitol/metabolismo , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/metabolismo , Staphylococcus haemolyticus/isolamento & purificação , Staphylococcus haemolyticus/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , DNA Girase/genética , DNA Bacteriano/genética , Genes Bacterianos/genética , Testes de Sensibilidade Microbiana , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Nigéria , Proteínas de Ligação às Penicilinas/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/patogenicidade , Suínos/microbiologiaRESUMO
A careful study of human axillary microflora led us to the identification of a new strain of Staphylococcus haemolyticus. The role in axillary malodour formation of this microorganism was compared to those of Corynebacterium xerosis and Staphylococcus epidermidis, upon incubation on sterile human eccrine and apocrine axilla sweat. St. haemolyticus was responsible for the strongest sulfury malodour and the generation of the volatile sulfur compound (VSC) (S)-3-methyl-3-sulfanylhexan-1-ol (3). In this study, we investigated the nonvolatile precursors of VSCs. Human axillary sweat was collected, fractionated and analysed by HPLC/APCI-MS (High-Pressure Liquid Chromatography coupled to Atmospheric Pressure Chemical Ionisation Mass Spectrometry). The precursor of 3 was identified as [1-(2-hydroxyethyl)-1-methylbutyl]-L-cysteinylglycine (Cys-Gly-(S)-conjugate; 12). Because Cys-Gly-(S)-conjugates are key intermediates in the glutathione biodetoxification pathway, other derivatives of 12, specifically glutathione-(S)-conjugate 11 and Cys-(S)-conjugate 13, were prepared. Compounds 11 and 13 were not detected by HPLC/MS of sterile sweat. Synthetic homologues 11, 12, and 13 were incubated with C. xerosis, St. heamolyticus, and St. epidermidis. We observed efficient conversion of precursors 12 and 13 to form VSCs when incubated with St. haemolyticus, with a clear preference for 12. C. xerosis and St. epidermidis were less efficient in cleaving Cys-Gly-(S)-conjugate 12 to form the corresponding thiol 3. Incubation of glutathione-(S)-conjugate 11 never led to the formation of 3 under the experimental conditions employed.