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Nutrients Dec 2022Proteases, especially microbial proteases, are widely used in food processing. The purpose of this study was aimed to purify an extracellular protease produced by the...
Proteases, especially microbial proteases, are widely used in food processing. The purpose of this study was aimed to purify an extracellular protease produced by the strain QB7 and to evaluate its ability in hydrolyzing meat proteins and generating antioxidant and anti-inflammatory peptides. The optimal conditions for producing the enzyme were as follows: inoculum ratio, 10%; initial pH, 6.5; temperature, 32 °C; incubation time, 36 h; and rotation speed, 160 rpm. The protease had a molecular weight of approximately 47 kDa, possessing the optimal activity at 50 °C, pH 7.0, The protease was stable at pH 4.0-8.0 and 30-60 °C, and the activity was improved by Na, Mg, Ca, and Zn ions, whereas it was inhibited by Cu, Co, Fe, Ba, Fe, β-M, and ethylene diamine tetraacetic acid disodium salt (EDTA). The protease could effectively hydrolyze meat proteins, and the generated hydrolysate could significantly inhibit tumor necrosis factor-alpha (TNFα)-induced oxidative stress, including superoxide and malondialdehyde levels and inflammation (vascular adhesion molecule-1 [VCAM-1] and cyclooxygenase 2 [COX2)) in human vascular EA.hy926 cells. The present findings support the ability of QB7 protease in generating antioxidant and anti-inflammatory peptides during the fermentation of meat products.
Topics: Humans; Peptide Hydrolases; Antioxidants; Meat Proteins; Endopeptidases; Peptides; Anti-Inflammatory Agents; Hydrogen-Ion Concentration
PubMed: 36615723
DOI: 10.3390/nu15010065 -
Veterinary Journal (London, England :... Jan 2015Since phenotypic methods to identify coagulase negative staphylococci (CNS) from the milk of ruminants often yield unreliable results, methods for molecular... (Review)
Review
Since phenotypic methods to identify coagulase negative staphylococci (CNS) from the milk of ruminants often yield unreliable results, methods for molecular identification based on gene sequencing or fingerprinting techniques have been developed. In addition to culture-based detection of isolates, culture-independent methods may be of interest. On the basis of molecular studies, the five CNS species commonly causing intramammary infections (IMI) are Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus simulans and Staphylococcus xylosus. Current knowledge suggests that S. chromogenes is a bovine-adapted species, with most cases of IMI due to this bacterium being opportunistic. S. haemolyticus also appears to be an opportunistic pathogen, but this bacterium occupies a variety of habitats, the importance of which as a source of IMI remains to be elucidated. S. xylosus appears to be a versatile species, but little is known of its epidemiology. S. epidermidis is considered to be a human-adapted species and most cases of IMI appear to arise from human sources, but the organism is capable of residing in other habitats. S. simulans typically causes contagious IMI, but opportunistic cases also occur and the ecology of this bacterium requires further study. Further studies of the ecology and epidemiology of CNS as a cause of IMI in cattle are required, along with careful attention to classification of these bacteria and the diseases they cause.
Topics: Animals; Bacteriological Techniques; Mastitis; Ruminants; Staphylococcal Infections; Staphylococcus
PubMed: 25467994
DOI: 10.1016/j.tvjl.2014.11.001 -
Antimicrobial Agents and Chemotherapy May 2020Recent studies highlight the abundance of commensal agulase-egative taphylococci (CoNS) on healthy skin. Evidence suggests that CoNS actively shape the skin...
Recent studies highlight the abundance of commensal agulase-egative taphylococci (CoNS) on healthy skin. Evidence suggests that CoNS actively shape the skin immunological and microbial milieu to resist colonization or infection by opportunistic pathogens, including methicillin-resistant (MRSA), in a variety of mechanisms collectively termed colonization resistance. One potential colonization resistance mechanism is the application of quorum sensing, also called the ccessory ene egulator () system, which is ubiquitous among staphylococci. Common and rare CoNS make autoinducing peptides (AIPs) that function as MRSA inhibitors, protecting the host from invasive infection. In a screen of CoNS spent media, we found that , a rare human skin colonizer and frequent livestock colonizer, released potent inhibitors of all classes of MRSA signaling. We identified three classes and have shown intraspecies cross talk between noncognate types for the first time. The AIP-I structure was confirmed, and the novel AIP-II and AIP-III structures were solved via mass spectrometry. Synthetic AIPs inhibited MRSA signaling with nanomolar potency. in competition with MRSA reduced dermonecrotic and epicutaneous skin injury in murine models. The addition of synthetic AIP-I also effectively reduced MRSA dermonecrosis and epicutaneous skin injury in murine models. These results demonstrate potent anti-MRSA quorum sensing inhibition by a rare human skin commensal and suggest that cross talk between CoNS and MRSA may be important in maintaining healthy skin homeostasis and preventing MRSA skin damage during colonization or acute infection.
Topics: Animals; Bacterial Proteins; Humans; Methicillin-Resistant Staphylococcus aureus; Mice; Peptides; Quorum Sensing; Staphylococcal Infections; Staphylococcus
PubMed: 32253213
DOI: 10.1128/AAC.00172-20 -
Biochimica Et Biophysica Acta.... Mar 2024Epilancin 15X is a lantibiotic that has an antimicrobial activity in the nanomolar concentration range towards Staphylococcus simulans. Such low MICs usually imply that... (Review)
Review
Epilancin 15X is a lantibiotic that has an antimicrobial activity in the nanomolar concentration range towards Staphylococcus simulans. Such low MICs usually imply that these peptides employ a mechanism of action (MoA) involving high affinity targets. Here we studied this MoA by using epilancin 15X's ability to dissipate the membrane potential of intact S. simulans cells. These membrane depolarization assays showed that treatment of the bacteria by antibiotics known to affect the bacterial cell wall synthesis pathway decreased the membrane depolarization effects of epilancin 15X. Disruption of the Lipid II cycle in intact bacteria using several methods led to a decrease in the activity of epilancin 15X. Antagonism-based experiments on 96-well plate and agar diffusion plate pointed towards a possible interaction between epilancin 15X and Lipid II and this was confirmed by Circular Dichroism (CD) based experiments. However, this interaction did not lead to a detectable effect on either carboxyfluorescein (CF) leakage or proton permeability. All experiments point to the involvement of a phosphodiester-containing target within a polyisoprene-based biosynthesis pathway, yet the exact identity of the target remains obscure so far.
Topics: Amino Acid Sequence; Bacteriocins; Anti-Bacterial Agents; Peptides
PubMed: 38218577
DOI: 10.1016/j.bbamem.2024.184282 -
Journal of Dairy Science Feb 2018Subclinical mastitis causes an increase in milk somatic cell count (SCC) and can lead to reduced milk production and early culling. In many countries, non-aureus...
Subclinical mastitis causes an increase in milk somatic cell count (SCC) and can lead to reduced milk production and early culling. In many countries, non-aureus staphylococci (NAS) is the most common bacterial finding in subclinical mastitis of dairy cows. New methodology makes it possible to identify NAS species, but knowledge about the epidemiology is limited. The objective of this project was to improve advisory services for mastitis control by investigating associations between NAS and SCC, milk production, and persistence of intramammary infections (IMI). Farmers who had sent milk samples to the Swedish National Veterinary Institute (Uppsala, Sweden) were asked to participate if NAS was identified in the samples. Participating farmers were asked to resample all udder quarters of the cow once within 1 mo. Regression models were used to investigate associations between NAS and cow factors, udder quarter California mastitis test and SCC, and persistence of IMI. Associations with cow composite milk yield and SCC were also investigated. In total, 671 cows from 201 herds were enrolled in the study, and 19 NAS species were identified, of which the 4 most common were Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus chromogenes, and Staphylococcus haemolyticus. Persistent IMI was more common in udder quarters with Staphylococcus hyicus and S. simulans and less common in those with Staphylococcus saprophyticus IMI. β-Lactamase production by the different NAS species varied from 0 to 100%. There was a significant association between NAS species and California mastitis test and SCC of udder quarters, and this varied depending on parity. The cow composite milk SCC at the test milking before the initial sample was taken differed significantly with NAS species, but not at the subsequent test milking. Milk yield-at the test milking before or after the initial sample-did not differ significantly for NAS species. There were no significant associations between milk yield or SCC and persistent NAS IMI. In conclusion, the NAS species affects SCC and persistent IMI differently but not milk yield.
Topics: Animals; California; Cattle; Cell Count; Dairying; Female; Mastitis, Bovine; Milk; Parity; Pregnancy; Staphylococcus; Staphylococcus epidermidis; Staphylococcus haemolyticus; Staphylococcus hyicus; Sweden; beta-Lactamases
PubMed: 29174143
DOI: 10.3168/jds.2017-13467 -
Central European Journal of Public... Jun 2022This work aimed to determine the representation and resistance of bacteria belonging to the genus Staphylococcus and Enterococcus on inanimate surfaces of two selected...
OBJECTIVES
This work aimed to determine the representation and resistance of bacteria belonging to the genus Staphylococcus and Enterococcus on inanimate surfaces of two selected workplaces of the University Hospital of L. Pasteur in Košice (UHLP) and to investigate their importance in the hospital environment. The men's ward of the Department of Internal Medicine (DIM) and the Department of Anaesthesiology and Intensive Care (DAIC) were chosen.
METHODS
Using sterile sampling kits, a total of 182 swabs were collected from the inanimate surfaces of both UHLP workplaces. The swabs were then transported to a microbiological laboratory and inoculated onto sterile culture media (blood agar containing 5% ram erythrocytes). After culturing (24-48 hours, in a thermostat at constant temperature 37 °C), bacterial colonies were identified by mass spectrometry on a MALDI TOF MS. Bacteria belonging to the genera Staphylococcus and Enterococcus were subsequently separated from the spectrum of identified bacteria. Nosocomial significant strains of staphylococci (Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus aureus) and all isolated enterococci were subjected to susceptibility testing for selected antibiotics using the disk diffusion method - E-tests.
RESULTS
Several members of the genus Staphylococcus were identified from the inanimate surfaces of both workplaces. These were mainly coagulase-negative strains - Staphylococcus epidermidis (45), Staphylococcus capitis (34), Staphylococcus haemolyticus (20), Staphylococcus hominis (45), Staphylococcus pasteuri (2), Staphylococcus sroph (1), Staphylococcus simulans (3), and Staphylococcus warneri (4). Staphylococcus aureus strains were also identified (2). Nosocomial significant isolates were tested for susceptibility to the antibiotics cefoxitin (FOX) and oxacillin (OXA). Two members of the genus Enterococcus - Enterococcus faecium (7) and Enterococcus faecalis (8) were isolated. All strains were subject to vancomycin susceptibility testing using the disk method.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Cross Infection; Enterococcus; Hospitals; Humans; Male; Microbial Sensitivity Tests; Sheep; Staphylococcal Infections; Staphylococcus
PubMed: 35841227
DOI: 10.21101/cejph.a7241 -
International Journal of Systematic and... Aug 2019A novel type strain, designated SDB 2975 (=CECT 9737=DSM 105892), of the novel species Staphylococcus debuckii sp. nov. isolated from bovine milk is described. The novel...
A novel type strain, designated SDB 2975 (=CECT 9737=DSM 105892), of the novel species Staphylococcus debuckii sp. nov. isolated from bovine milk is described. The novel species belongs to the genus Staphylococcus and showed resistance to tetracycline and was oxidase- and coagulase-negative, catalase-positive, and Gram-stain-positive. Phylogenetic relationships of Staphylococcus debuckii SDB 2975 to other staphylococcal species were inferred from 16S rRNA gene and whole-genome-based phylogenetic reconstruction. The 16S rRNA gene comparisons showed that the strain is closely related to Staphylococcus condimenti (99.73 %), Staphylococcus piscifermentans (99.66 %), Staphylococcus carnosus (99.59 %) and Staphylococcus simulans (98.03 %). Average nucleotide identity (ANI) values between S.taphylococcus debuckii SDB 2975 and its closely related Staphylococcus species were 83.96, 94.5, 84.03 and 78.09 %, respectively, and digital DNA-DNA hybridization (dDDH) values were 27.70, 58.02, 27.70 and 22.00 %, respectively. The genome of Staphylococcus debuckii SDB 2975 was sequenced with PacBio and Illumina technologies and is 2 691 850 bp long, has a G+C content of 36.6 mol% and contains 2678 genes and 80 RNAs, including six copies of each5S rRNA, 16S rRNA and 23S rRNA genes. Biochemical profiling and a newly developed PCR assay enabled differentiation of Staphylococcus debuckii SDB 2975 and three other SDB strains from its closest staphylococcal species. Differentiation was also achieved by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). Genes unique to Staphylococcus debuckii were identified and a PCR-based assay was developed to differentiate Staphylococcus debuckii from other staphylococcal species. In conclusion, the results of phylogenetic analysis along with the ANI values <95 %, and dDDH values <70 % from closely related species along with the phenotypic and biochemical characteristics and specific MALDI-TOF profiles demonstrated that Staphylococcus debuckii SDB 2975 represents a novel species within the genus Staphylococcus, named Staphylococcus debuckii sp. nov. (SDB 2975=CECT 9737=DSM 105892).
Topics: Animals; Bacterial Typing Techniques; Base Composition; Cattle; DNA, Bacterial; Fatty Acids; Milk; Nucleic Acid Hybridization; Phylogeny; Quebec; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Staphylococcus
PubMed: 31135334
DOI: 10.1099/ijsem.0.003457 -
Environmental Research Apr 2019The airborne fungal and bacterial species present in pig farm dust have not been well characterised even though these bioaerosols are known to cause inflammation and...
The airborne fungal and bacterial species present in pig farm dust have not been well characterised even though these bioaerosols are known to cause inflammation and other airway maladies. In this study, the microbial species and composition in airborne dust within and between pig farms were investigated. Passively sedimenting dust from six pig farms were collected using electrostatic dust collectors. The bacterial and fungal species were identified using matrix-assisted laser desorption-ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and next generation sequencing (NGS). Dust samples taken within the same stable section revealed high resemblance and stability. Constrained statistical analysis of the microbial community compositions indicated that the types of stable did not appear to have a great effect on the bacterial and fungal β-diversity. In contrast to this, the farm from which samples were taken appeared to have the greatest effect on the bacterial β-diversity, but this trend was not observed for the fungal β-diversity. The most common bacteria and fungi according to NGS data were anaerobes typically associated with the pig intestinal tract and yeasts respectively. Bacterial sedimentation varied at a rate between 10 and 10 CFU/m/day, with the most common species after aerobic incubation being Aerococcus viridans and Staphylococcus equorum, while Clostridium perfringens and Staphylococcus simulans were the most common species after anaerobic incubation. A total of 28 different species of bacteria and fungi were classifiable as pathogens. In conclusion, the biodiversity in pig farm dust shows a high diversity of bacterial species. However, samples from the same stable section resembled each other, but also different sections within the same farm also resembled each other, thus indicating a high degree of community stability in the dust source. In regards to fungal identification, the biodiversity was observed to be similar between samples from different stable sections and farms, indicating a higher degree of similarities in the mycobiomes found across pig farms studied.
Topics: Air Microbiology; Animals; Bacteria; Biodiversity; Dust; Environmental Monitoring; Farms; Fungi; Swine
PubMed: 30771719
DOI: 10.1016/j.envres.2019.01.008 -
Food Research International (Ottawa,... Dec 2022Chinese traditional fermented meat products in Guizhou province harbor a unique microbial community owing to particular geographical, environmental, and climatic...
Chinese traditional fermented meat products in Guizhou province harbor a unique microbial community owing to particular geographical, environmental, and climatic conditions. In this study, coagulase-negative staphylococci (CNS) with high protease activity were isolated from a Guizhou traditional naturally fermented meat product, i.e., Qianwufu sausages. In addition, the potential of isolated CNS strains to be used as starter cultures in sausage fermentation was evaluated. Culture- and molecular-biology-based methods were employed to isolate and identify CNS. A total of 40 CNS strains could hydrolyze pork meat proteins. In particular, strain QB7 identified as Staphylococcus simulans had the highest proteolytic activity, was resistant to growth in the presence of 6.5 % NaCl and 150 mg/kg of nitrites, and lacked virulence genes, hemolytic, decarboxylase, DNase, and biofilm-forming activities. Subsequently, S. simulans QB7 was used as a starter in sausage fermentation, which led to an increase in competitiveness of dominant bacteria, reduced growth of undesirable bacteria, higher content of total free fatty acids and free amino acids, and lower pH and water activity values. Thus, S. simulans QB7 can potentially be used as a starter to improve the quality and nutritional properties of fermented meat products.
Topics: Meat Products; Coagulase; Peptide Hydrolases; Proteolysis; Pork Meat
PubMed: 36461208
DOI: 10.1016/j.foodres.2022.111957 -
Pathogens (Basel, Switzerland) Feb 2023Antimicrobials are added to semen extenders to inhibit the growth of bacteria that are transferred to the semen during collection. However, this non-therapeutic use of...
Antimicrobials are added to semen extenders to inhibit the growth of bacteria that are transferred to the semen during collection. However, this non-therapeutic use of antimicrobials could contribute to the development of antimicrobial resistance. The objective of this study was to determine changes in the antibiotic susceptibility of vaginal microbiota after artificial insemination. Swabs were taken from the vagina of 26 mares immediately before artificial insemination and again 3 days later. Bacteria isolated from the vagina at both time points were subjected to antibiotic susceptibility testing and whole-genome sequencing. In total, 32 bacterial species were identified. There were increases in the resistance of to trimethoprim ( = 0.0006), chloramphenicol and ( = 0.012) tetracycline ( = 0.03) between day 0 and day 3. However, there was no significant effect of exposure to antibiotics in semen extenders with respect to the resistance of and ( > 0.05). Whole-genome sequencing indicated that most phenotypic resistance was associated with genes for resistance. These results indicate that the resistance patterns of vaginal bacteria may be affected by exposure to antibiotics; therefore, it would be prudent to minimize, or preferably, avoid using antibiotics in semen extenders.
PubMed: 36986297
DOI: 10.3390/pathogens12030375