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FEMS Microbiology Letters Apr 1989The peptidoglycan hydrolyzing endo-beta-N-acetylglucosaminidase of Staphylococcus simulans 22 is not able to attack intact cell walls of S. simulans 22, but hydrolyzes...
The peptidoglycan hydrolyzing endo-beta-N-acetylglucosaminidase of Staphylococcus simulans 22 is not able to attack intact cell walls of S. simulans 22, but hydrolyzes cell walls of Micrococcus luteus and soluble peptidoglycan chains of S. simulans 22. Hydrolysis of cell walls of M. luteus is activated in presence of organic cations such as poly-L-lysine (n = 17) and the peptide antibiotics Pep 5 and nisin, whereas hydrolysis of soluble peptidoglycan chains is not influenced. High concentrations of inorganic cations inhibit enzyme activity. These effects are discussed with respect to the cationic nature of the enzyme (pI greater than 9.5) and the regulation of the concerted action of the N-acetylmuramoyl-L-alanine amidase and the glucosaminidase during S. simulans 22 autolysis in vivo.
Topics: Acetylglucosaminidase; Anti-Bacterial Agents; Autolysis; Bacteriocins; Cations; Cell Wall; Hexosaminidases; Kinetics; Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; Nisin; Peptides; Staphylococcus
PubMed: 2501145
DOI: 10.1016/0378-1097(89)90042-6 -
Molecular and Cellular Probes Apr 2012The recently described phenol-soluble modulin PSM-mec was detected in Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus fleuretti, Staphylococcus...
The recently described phenol-soluble modulin PSM-mec was detected in Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus fleuretti, Staphylococcus hominis, Staphylococcus pseudintermedius, Staphylococcus saprophyticus, Staphylococcus simulans and Staphylococcus vitulinus from different hosts (humans, goats, dogs, cats, pigs, cattle and turkeys). It was identified in isolates harbouring SCCmec types II, IIA, IIB, IID, III, VIII and in some irregular or truncated elements.
Topics: Animals; Bacterial Proteins; Genotype; Humans; Polymerase Chain Reaction; Sequence Analysis, DNA; Staphylococcus; Virulence Factors
PubMed: 22251619
DOI: 10.1016/j.mcp.2012.01.001 -
Journal of Dairy Science Jul 2017The effect of non-aureus staphylococci (NAS) in bovine mammary health is controversial. Overall, NAS intramammary infections (IMI) increase somatic cell count (SCC),...
The effect of non-aureus staphylococci (NAS) in bovine mammary health is controversial. Overall, NAS intramammary infections (IMI) increase somatic cell count (SCC), with an effect categorized as mild, mostly causing subclinical or mild to moderate clinical mastitis. However, based on recent studies, specific NAS may affect the udder more severely. Some of these apparent discrepancies could be attributed to the large number of species that compose the NAS group. The objectives of this study were to determine (1) the SCC of quarters infected by individual NAS species compared with NAS as a group, culture-negative, and major pathogen-infected quarters; (2) the distribution of NAS species isolated from quarters with low SCC (<200,000 cells/mL) and high SCC (≥200,000 cells/mL), and clinical mastitis; and (3) the prevalence of NAS species across quarters with low and high SCC. A total of 5,507 NAS isolates, 3,561 from low SCC quarters, 1,873 from high SCC quarters, and 73 from clinical mastitis cases, were obtained from the National Cohort of Dairy Farms of the Canadian Bovine Mastitis Research Network. Of quarters with low SCC, high SCC, or clinical mastitis, 7.6, 18.5, and 4.3% were NAS positive, respectively. The effect of NAS IMI on SCC was estimated using mixed-effect linear regression; prevalence of NAS IMI was estimated using Bayesian analyses. Mean SCC of NAS-positive quarters was 70,000 cells/mL, which was higher than culture-negative quarters (32,000 cells/mL) and lower than major pathogen-positive quarters (129,000 to 183,000 cells/mL). Compared with other NAS species, SCC was highest in quarters positive for Staphylococcus capitis, Staphylococcus gallinarum, Staphylococcus hyicus, Staphylococcus agnetis, or Staphylococcus simulans. In NAS-positive quarters, Staphylococcus xylosus (12.6%), Staphylococcus cohnii (3.1%), and Staphylococcus equorum (0.6%) were more frequently isolated from quarters with low SCC than other NAS species, whereas Staphylococcus sciuri (14%) was most frequently isolated from clinical mastitis cases. Finally, in NAS-positive quarters, Staphylococcus chromogenes, S. simulans, Staphylococcus epidermidis, and Staphylococcus haemolyticus were isolated with similar frequency from among low SCC and high SCC quarters and clinical mastitis cases. Staphylococcus chromogenes, S. simulans, S. xylosus, S. haemolyticus, S. epidermidis, S. agnetis, Staphylococcus arlettae, S. capitis, S. gallinarum, S. sciuri, and Staphylococcus warneri were more prevalent in high than in low SCC quarters. Because the NAS are a large, heterogeneous group, considering them as a single group rather than at the species, or even subspecies level, has undoubtedly contributed to apparent discrepancies among studies as to their distribution and importance in IMI and mastitis.
Topics: Animals; Bayes Theorem; Canada; Cattle; Cell Count; Female; Mammary Glands, Animal; Mastitis, Bovine; Milk; Staphylococcal Infections; Staphylococcus
PubMed: 28456402
DOI: 10.3168/jds.2016-12479 -
Microbiologica Oct 1983Biochemical and physical properties of the pure bacteriolytic enzymes excreted by three different Staphylococcus species (S. aureus, S. simulans, and S. saprophyticus)...
Biochemical and physical properties of the pure bacteriolytic enzymes excreted by three different Staphylococcus species (S. aureus, S. simulans, and S. saprophyticus) were investigated. Although the three enzymes have previously been shown to share the same specificity of action (endo-beta-N-acetylglucosaminidase activity), their biochemical features clearly indicated that they were three different enzymes, confirming what had previously been suggested by the different lytic-activity patterns displayed by each species and the different procedures needed to achieve purification of each enzyme. Very different values resulted from molecular weight determination: 80,000 for the S. aureus enzyme, 45,000 for the S. simulans enzyme and 31,000 for the S. saprophyticus enzyme. Other important differences were observed in their kinetics of activity on Micrococcus luteus purified cell walls; their stability; their bacteriolytic spectrum against heat-killed cells of various microorganisms; and their response to physical and chemical factors, such as temperature, pH, ionic strength, divalent cations, chelating agents, thiol compounds, and glucose derivatives.
Topics: Acetylglucosaminidase; Bacteriolysis; Chelating Agents; Hexosaminidases; Hydrogen-Ion Concentration; Kinetics; Magnesium; Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; Molecular Weight; Staphylococcus; Staphylococcus aureus; Temperature
PubMed: 6420648
DOI: No ID Found -
Drug Metabolism and Personalized Therapy Dec 2023Antibiotic resistance is rising, prompting innovative strategies for eradicating the epidemic. This study investigated the antibacterial properties of the leaves of a...
OBJECTIVES
Antibiotic resistance is rising, prompting innovative strategies for eradicating the epidemic. This study investigated the antibacterial properties of the leaves of a widely used medicinal plant, .
METHODS
The plant's polar (water, methanol) and non-polar (hexane) extracts were tested against several different bacterial strains using the disc diffusion technique.
RESULTS
In a study, it was found that the water extract had the greatest inhibitory effect on and , with minimum inhibitory concentrations of 16.444 and 19.315 g/mL, respectively. Gram-negative strains were more susceptible to plant extracts than Gram-positive strains. The phytochemical analysis indicated the presence of secondary metabolites such as alkaloids, saponins, flavonoids, tannins, and steroids, where absorbance was recorded at 415 nm. The water extract had the highest amount of phenolics, with a total phenolic content of 53.92 0.47 mg and a total flavonoid content of 7.25 0.08 mg. Results suggest that the extract may have potential therapeutic applications for antimicrobial properties.
CONCLUSIONS
The study concluded that the extract's phenolic group of secondary metabolites were responsible for its antibacterial activity. The study highlights as a promising source for discovering new and effective antibacterial compounds.
Topics: Humans; Plants, Medicinal; Plant Extracts; Justicia; Anti-Infective Agents; Anti-Bacterial Agents; Flavonoids; Water; Phenols; Plant Leaves
PubMed: 37381682
DOI: 10.1515/dmpt-2023-0012 -
Veterinary Microbiology Feb 2009Coagulase-negative Staphylococcus species (CNS) were isolated from 11.3% (1407 of 12,412) of mammary quarter milk samples obtained from cows in three dairy research...
Coagulase-negative Staphylococcus species (CNS) were isolated from 11.3% (1407 of 12,412) of mammary quarter milk samples obtained from cows in three dairy research herds in 2005. Approximately 27% (383/1407) of CNS was identified to the species level. The species distribution among those CNS identified from all herds was Staphylococcus chromogenes (48%), Staphylococcus hyicus (26%), Staphylococcus epidermidis (10%), Staphylococcus simulans (7%), Staphylococcus warneri (2%), Staphylococcus hominis (2%), Staphylococcus saprophyticus (1%), Staphylococcus xylosus (1%), Staphylococcus haemolyticus (<1%), Staphylococcus sciuri (<1%), and Staphylococcus intermedius (<1%). Staphylococcuschromogenes was the predominant CNS isolated from all three herds; however, differences were seen in the prevalence of other CNS species. A total of 158 CNS (S. chromogenesn=66, S. hyicusn=38, S. epidermidisn=37, S. simulans n=10, and S. warneri n=7) were analyzed by pulsed-field gel electrophoresis (PFGE). The majority (33/41) of CNS isolated from the same mammary quarter on more than one occasion had the same PFGE pattern indicating persistence of the same infection over time. When all PFGE patterns for each CNS were analyzed, no common pulsotype was seen among the three herds indicating that CNS are quite diverse. Composite milk somatic cell count (SCC) data were obtained +/-14d of when CNS were isolated. Average milk SCC (5.32 log(10)/ml) for cows in which CNS was the only bacteria isolated was significantly higher than the average milk SCC (4.90 log(10)/ml) from cows with quarter milk samples that were bacteriologically negative.
Topics: Animals; Cattle; Coagulase; Dairying; Female; Mastitis, Bovine; Milk; Phylogeny; Prevalence; Staphylococcal Infections; Staphylococcus
PubMed: 18950962
DOI: 10.1016/j.vetmic.2008.09.007 -
Veterinary World Dec 2023The agar dilution method is the approved method for determining the minimum inhibitory concentration (MIC) in fosfomycin susceptibility testing, whereas the broth...
BACKGROUND AND AIM
The agar dilution method is the approved method for determining the minimum inhibitory concentration (MIC) in fosfomycin susceptibility testing, whereas the broth dilution method is not recommended. This study aimed to investigate the potential of the gradient diffusion method as a more convenient alternative to agar dilution method for MIC evaluation, particularly for the susceptibility testing of spp. and spp. to fosfomycin.
MATERIALS AND METHODS
A total of 194 isolates of spp. and spp. were collected from urine samples of dogs diagnosed with bacterial cystitis. Bacterial identification and susceptibility to multiple antibiotics were tested using the Vitek 2 automated system. The susceptibility to fosfomycin was compared between agar dilution (reference method) and the gradient diffusion method. We assessed the agreement rates and errors between the two approaches by analyzing the MIC data.
RESULTS
(98.7%) and (80.0%) exhibited high fosfomycin susceptibility rates, whereas exhibited a lower susceptibility rate (38.5%). The gradient diffusion method demonstrated unacceptably low essential agreement (EA) rates (>90%) but acceptable categorical agreement (CA) rates (≥ 90%) for (83.54% EA and 97.47% CA) and coagulase-negative staphylococci (CoNS) such as , , and (85.00% EA and 95.00% CA). spp. had an acceptable EA of 93.75%, but an unacceptably low CA rate of 82.81%, with a minor error rate of 17.19%. No significant errors were observed for and spp.
CONCLUSION
The gradient diffusion method reliably determines MICs and interpretative breakpoints (S, I, R) for . However, its applicability to CoNS and enterococci may be limited due to unacceptable errors.
PubMed: 38328370
DOI: 10.14202/vetworld.2023.2497-2503 -
Acta Microbiologica Hungarica 1985Localization and genetic nature of inducible macrolide resistance determinants in some coagulase negative staphylococci (CNS) were studied and compared with those in...
Localization and genetic nature of inducible macrolide resistance determinants in some coagulase negative staphylococci (CNS) were studied and compared with those in Staphylococcus aureus. An 1.7-megadalton R-plasmid, pEI 1107, mediating inducible resistance to macrolides and lincosamides was present in part of Staphylococcus simulans and Staphylococcus epidermidis strains isolated in the Central Hospital for Infectious Diseases. Two other plasmids were harboured by S. simulans LK 6108 strain. One of these plasmids, pEI 6108 (molecular mass 5.2 Md) was encoded for inducible macrolide-lincosamide resistance, and the second one, pE 6108 (molecular mass 4.9 Md) for constitutive marcolide resistance. The similarity in size and phenotype of small plasmids in CNS and S. aureus suggest a common origin of these resistance determinants.
Topics: DNA, Bacterial; Electrophoresis, Agar Gel; Erythromycin; Lincomycin; Phenotype; R Factors; Staphylococcus; Staphylococcus epidermidis
PubMed: 4082898
DOI: No ID Found -
Veterinary Research Apr 2021Communications via quorum sensing (QS) between non-aureus staphylococci (NAS) and Staphylococcus (S.) aureus in the bovine mammary gland remains largely unexplored. We...
Communications via quorum sensing (QS) between non-aureus staphylococci (NAS) and Staphylococcus (S.) aureus in the bovine mammary gland remains largely unexplored. We determined whether 34 S. chromogenes, 11 S. epidermidis, and 14 S. simulans isolates originating from bovine milk samples and teat apices were able to regulate the QS of S. aureus, and if so, how in vitro growth inhibition of S. aureus by NAS, or NAS metabolites, or NAS cells themselves play a role in this process. In co-culture with S. aureus we observed that these 3 NAS species in general downregulated the expression of rnaIII, the effector molecule of the QS system, but this effect was more pronounced in S. chromogenes and S. simulans isolates than in S. epidermidis isolates. In vitro growth inhibition of S. aureus by NAS resulted in a small underestimation of the downregulating effect of NAS on rnaIII expression of S. aureus. Additionally, the culture supernatant of these NAS isolates and supernatant treated with proteinase K expressed greater regulatory activity over S. aureus virulence genes rnaIII, hla, and spa than washed NAS cells suspended in sterile water. These microbial interactions may influence S. aureus virulence and pathogenesis within the host. Isolation and identification of NAS metabolites affecting the QS system of S. aureus might help to develop alternative strategies for treatment and control of S. aureus mastitis.
Topics: Animals; Bacterial Proteins; Down-Regulation; Gene Expression Regulation, Bacterial; Mammary Glands, Animal; Milk; Quorum Sensing; Staphylococcus; Staphylococcus aureus; Trans-Activators
PubMed: 33926572
DOI: 10.1186/s13567-021-00933-x -
Journal of Dairy Science Dec 2012The aim of this study was to investigate whether the main coagulase-negative staphylococci (CNS) species involved in bovine intramammary infections (IMI) possess...
Characterization of coagulase-negative staphylococcus species from cows' milk and environment based on bap, icaA, and mecA genes and phenotypic susceptibility to antimicrobials and teat dips.
The aim of this study was to investigate whether the main coagulase-negative staphylococci (CNS) species involved in bovine intramammary infections (IMI) possess specific characteristics that promote colonization of the udder. Virulence markers associated with biofilm formation, antimicrobial resistance, and biocide tolerance were compared between typically contagious CNS species (Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus simulans) and those rarely causing IMI (Staphylococcus sciuri, Staphylococcus equorum, and others) to find possible associations with pathogenicity. Coagulase-negative staphylococci isolates (n=366) belonging to 22 different species were analyzed by PCR for the presence of the biofilm-associated genes bap and icaA, and the methicillin resistance gene mecA. A selection of 82 isolates was additionally tested for their susceptibility to 5 antibiotics and 2 commercial teat dip products. Minimum inhibitory concentrations of antimicrobials were determined by Etest (AB bioMérieux, Marcy l'Etoile, France), and a microdilution method was optimized to determine minimum biocidal concentrations of teat dips. The bap, icaA, and mecA genes were detected significantly more in isolates from CNS species typically living in the cows' environment than in isolates from IMI-causing species. Antimicrobial resistance was mainly against erythromycin (23%) or oxacillin (16%), and was detected more often in the environmental species. The isolates least susceptible to the teat dips belonged to the IMI-causing species Staph. chromogenes and Staph. simulans. We concluded that carriage of biofilm genes and antimicrobial resistance were not associated with the ability to colonize the mammary gland because free-living CNS species constituted a more significant reservoir of biofilm and resistance determinants than did IMI-causing species. In contrast, increased tolerance to biocides may favor the establishment of bovine IMI by some CNS species.
Topics: Animals; Anti-Infective Agents; Bacterial Proteins; Cattle; Drug Resistance, Bacterial; Female; Genes, Bacterial; Mammary Glands, Animal; Mastitis, Bovine; Microbial Sensitivity Tests; Milk; Phenotype; Staphylococcal Infections; Staphylococcus; Staphylococcus epidermidis; Staphylococcus haemolyticus
PubMed: 22999285
DOI: 10.3168/jds.2012-5400