scholarly journals Pantothenate-requiring dwarf colony variants ofStaphylococcus aureusas the etiological agent in bovine mastitis

1969 ◽  
Vol 67 (3) ◽  
pp. 511-516 ◽  
Author(s):  
D. Sompolinsky ◽  
I. Gluskin ◽  
G. Ziv
Keyword(s):  
Staphylococcus Aureus ◽  
Metabolic Disorder ◽  
Bovine Mastitis ◽  
Etiological Agent

SUMMARYIn a herd affected with bovine mastitis, dwarf colony variants ofStaphylococcus aureus, auxotrophic for Ca-pantothenate, were isolated from the milk of four cows with mastitis. From one of these cows, a dwarf variant with an unknown metabolic disorder was isolated during the same period. Infections with auxo trophic staphylococci were always chronic and proved to be refractory to anti biotic treatment, though the causative micro-organism was highly susceptible to the drugs used as judged byin vitrotests.The authors acknowledge with appreciation the skilful help of Miss Nili Abramova.

scholarly journals Within-Host Adaptation of Staphylococcus aureus in a Bovine Mastitis Infection Is Associated with Increased Cytotoxicity

2021 ◽  
Vol 22 (16) ◽  
pp. 8840
Author(s):  
Katharina Mayer ◽  
Martin Kucklick ◽  
Helene Marbach ◽  
Monika Ehling-Schulz ◽  
Susanne Engelmann ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Adaptive Strategy ◽  
Subclinical Mastitis ◽  
Growth Conditions ◽  
Typical Feature ◽  
Host Adaptation ◽  
Bovine Mammary Epithelial Cells ◽  
Strain Pair

Within-host adaptation is a typical feature of chronic, persistent Staphylococcus aureus infections. Research projects addressing adaptive changes due to bacterial in-host evolution increase our understanding of the pathogen’s strategies to survive and persist for a long time in various hosts such as human and bovine. In this study, we investigated the adaptive processes of S. aureus during chronic, persistent bovine mastitis using a previously isolated isogenic strain pair from a dairy cow with chronic, subclinical mastitis, in which the last variant (host-adapted, Sigma factor SigB-deficient) quickly replaced the initial, dominant variant. The strain pair was cultivated under specific in vitro infection-relevant growth-limiting conditions (iron-depleted RPMI under oxygen limitation). We used a combinatory approach of surfaceomics, molecular spectroscopic fingerprinting and in vitro phenotypic assays. Cellular cytotoxicity assays using red blood cells and bovine mammary epithelial cells (MAC-T) revealed changes towards a more cytotoxic phenotype in the host-adapted isolate with an increased alpha-hemolysin (α-toxin) secretion, suggesting an improved capacity to penetrate and disseminate the udder tissue. Our results foster the hypothesis that within-host evolved SigB-deficiency favours extracellular persistence in S. aureus infections. Here, we provide new insights into one possible adaptive strategy employed by S. aureus during chronic, bovine mastitis, and we emphasise the need to analyse genotype–phenotype associations under different infection-relevant growth conditions.

scholarly journals Efficacy of Bacteriophages Against Staphylococcus aureus Isolates from Bovine Mastitis

2020 ◽  
Vol 13 (3) ◽  
pp. 35 ◽  
Author(s):  
Isabel Titze ◽  
Tatiana Lehnherr ◽  
Hansjörg Lehnherr ◽  
Volker Krömker
Keyword(s):  
Staphylococcus Aureus ◽  
Host Range ◽  
Bacterial Infections ◽  
Plaque Assay ◽  
Bovine Milk ◽  
Bovine Mastitis ◽  
Raw Milk ◽  
Pasteurized Milk

The lytic efficacy of bacteriophages against Staphylococcus aureus isolates from bovine milk was investigated in vitro, regarding possible applications in the therapy of udder inflammation caused by bacterial infections (mastitis). The host range of sequenced, lytic bacteriophages was determined against a collection of 92 Staphylococcus (S.) aureus isolates. The isolates originated from quarter foremilk samples of clinical and subclinical mastitis cases. A spot test and a subsequent plaque assay were used to determine the phage host range. According to their host range, propagation and storage properties, three phages, STA1.ST29, EB1.ST11, and EB1.ST27, were selected for preparing a bacteriophage mixture (1:1:1), which was examined for its lytic activity against S. aureus in pasteurized and raw milk. It was found that almost two thirds of the isolates could be lysed by at least one of the tested phages. The bacteriophage mixture was able to reduce the S. aureus germ density in pasteurized milk and its reduction ability was maintained in raw milk, with only a moderate decrease compared to the results in pasteurized milk. The significant reduction ability of the phage mixture in raw milk promotes further in vivo investigation.

scholarly journals Risk factors associated with the antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis

2014 ◽  
Vol 34 (10) ◽  
pp. 947-952 ◽  
Author(s):  
Daniele C. Beuron ◽  
Cristina S. Cortinhas ◽  
Bruno G. Botaro ◽  
Susana N. Macedo ◽  
Juliano L. Gonçalves ◽  
...  
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Management Practices ◽  
Bovine Mastitis ◽  
Factors Associated ◽  
Milk Samples ◽  
Treatment Procedures

The objective of this study was to evaluate herd management practices and mastitis treatment procedures as risk factors associated with Staphylococcus aureus antimicrobial resistance. For this study, 13 herds were selected to participate in the study to evaluate the association between their management practices and mastitis treatment procedures and in vitro antimicrobial susceptibility. A total of 1069 composite milk samples were collected aseptically from the selected cows in four different periods over two years. The samples were used for microbiological culturing of S. aureus isolates and evaluation of their antimicrobial susceptibility. A total of 756 samples (70.7%) were culture-positive, and S. aureus comprised 27.77% (n=210) of the isolates. The S. aureus isolates were tested using the disk-diffusion susceptibility assay with the following antimicrobials: ampicillin 10mg; clindamycin 2μg; penicillin 1mg; ceftiofur 30μg; gentamicin 10mg; sulfa-trimethoprim 25μg; enrofloxacin 5μg; sulfonamide 300μg; tetracycline 30μg; oxacillin 1mg; cephalothin 30μg and erythromycin 5μg. The variables that were significantly associated with S. aureus resistance were as follows: the treatment of clinical mastitis for ampicillin (OR=2.18), dry cow treatment for enrofloxacin (OR=2.11) and not sending milk samples for microbiological culture and susceptibility tests, for ampicillin (OR=2.57) and penicillin (OR=4.69). In conclusion, the identification of risk factors for S. aureus resistance against various mastitis antimicrobials is an important information that may help in practical recommendations for prudent use of antimicrobial in milk production.

scholarly journals Antıbacterıal potentıal of anthocyanıc extracts of strawberry on Staphylococcus aureus assocıated to bovıne mastıtıs

2018 ◽  
Vol 28 (5) ◽  
pp. 52-57
Author(s):  
Jeanette Guadalupe Cárdenas-Valdovinos ◽  
Guadalupe Oyoque-Salcedo ◽  
Pedro Damian Loeza-Lara ◽  
Ernesto Oregel-Zamudio ◽  
Maria Valentina Angoa-Perez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Growth ◽  
Bovine Mastitis ◽  
Positive Control ◽  
Fragaria X Ananassa ◽  
In Vitro Growth ◽  
Strain Atcc ◽  
Sensitivity Tests ◽  
Antibacterial Potential

In this study, the effect of anthocyanic extracts of strawberry (Fragaria x ananassa Duch.) variety Jacona on the in vitro growth of Staphylococcus aureus associated to bovine mastitis was evaluated. Sensitivity tests were carried out on the anthocyanic extracts by disk difussion method (10 µg/disk-100 µg/disk), using the antibiotic Dicloxacillin® as positive control (50 µg/mL, 50 µL/disk) and percentages of inhibition of bacterial growth were determined. Anthocyanic extracts managed to inhibit the bacterial growth of the strain ATCC 27543 and the isolated STA28 of S. aureus up to 54% and 40%, respectively. The results showed the antimicrobial potential of anthocyanic extracts of strawberry against S. aureus associated to bovine mastitis.

scholarly journals Escherichia coli and Staphylococcus aureus responsible for bovine mastitis sensitivity to the essential oil of Algerian Thymus fontanesii Boiss. et Reut.

2020 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
Bendella Amina nor elhouda ◽  
Ghazi Kheira ◽  
Meliani Samia
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Bovine Mastitis ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Zones Of Inhibition

AbstractThe aim of this study is to test two different methods for evaluating the in vitro antibacterial effect of Thymus fontanesii Boiss. et Reut. essential oil against standard and clinical bacterial strains responsible for bovine mastitis: the disc diffusion method or the aromatogram which allows the demonstration of the antibacterial power of essential oils on the bacterial strains tested, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and two strains isolated from bovine mastitis milk S. aureus and E. coli. The inhibition activity of the essential oil of T. fontanesii on bacterial strains by the two methods shows that the antimicrobial power of this oil is very important and is characterized by bactericidal and bacteriostatic action against gram negative and gram positive bacteria. The antimicrobial evaluation by the aromatogram showed good antibacterial activity against all the strains tested, the zones of inhibition of the bacteria were between 23,33±1,527mm and 37,5±3,535 mm. The search for minimum inhibitory concentrations MIC and bactericides CMB made it possible to quantitatively assess the antimicrobial power of this essential oil. In this work, the MIC was 0,625 µl/ml for all strains tested, and the lowest CMB was that of T. fontanesii against E. coli ATCC 25922 was 0,625 µl/ml.

Staphylococcus aureus leucocidin, a virulence factor in bovine mastitis

2005 ◽  
Vol 72 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Ahmed Younis ◽  
Oleg Krifucks ◽  
Gideon Fleminger ◽  
Elimelech D Heller ◽  
Natan Gollop ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mononuclear Cells ◽  
Gel Filtration ◽  
Bovine Mastitis ◽  
Culture Broth ◽  
Protein Sequencing ◽  
Staph Aureus ◽  
Proliferation Response

The involvement of Staphylococcus aureus exosecretions in bovine udder infection (Younis et al. 2003) suggests that four different monomer protein bands appearing between 36 and 31 kDa, are associated with the severity of the cow's infection response. Three out of these four bands have been identified by means of protein sequencing. Band B, with a MW of 35 kDa was identified as Panton-Valentaine leucocidin LukF'-PV chain- Staph. aureus; band C, with a MW of 32 kDa was identified as leucocidin chain LukM precursor- Staph. aureus; and band D was found to be similar, but not identical, to phosphatidylinositol-specific phospholipase-C-X. Bands B and C were purified by gel filtration using FPLC. The ability of these proteins to induce udder inflammation in vivo, and proliferation response in vitro and cytokine secretion were tested for both the crude exosecretions and purified bands. Three cows were inoculated intracisternally, with three quarters receiving either 0·007–0·008 mg (as total proteins) of Staph. aureus FR2449/1 bacterial exosecretion, pooled fraction 39–41 (bands B and C), or culture broth medium. The fourth quarter was left free as a control. Quarters that received fraction 39–41 of Staph. aureus FR2449/1, exhibited induced inflammation, which was indicated by increased somatic cell count and enhanced NAGase activity that was significantly higher than that of the original Staph. aureus FR2449/1 bacterial exosecretion. Proliferation tests of bovine blood lymphocytes in vitro showed that the pooled fraction 39–41 stimulated bovine proliferation of mononuclear cells much more than the original Staph. aureus FR2449/1 bacterial exosecretion. Secretion of TNF-α, IL-1β, IL-6 and IL-8 was in accordance with the contents of LukF'-PV and LukM precursor in the exosecretions. The results suggest that LukM/LukF' induce inflammation into the udder by a mechanism similar to that of LPS or by a unique mechanism(s) which requires further investigation.

Sign in / Sign up

Export Citation Format

Share Document