The Postantibiotic Effect of Selected Antibiotics on Staphylococcus aureus Newbould 305 from Bovine Intramammary Infection

1993 ◽  
Vol 40 (1-10) ◽  
pp. 603-608 ◽  
Author(s):  
W. E. Owens ◽  
P. J. Washburn ◽  
C. H. Ray
1965 ◽  
Vol 32 (2) ◽  
pp. 171-179 ◽  
Author(s):  
F. H. S. Newbould ◽  
F. K. Neave

SummaryFifty-seven inoculations of a strain of Staphylococcus aureus were made into the outer 4 mm of the teat ducts of 8 cows. The inocula ranged from 10 to 600 colony-forming units (CFU) and were made with a stainless steel instrument designed to overcome the disadvantages of glass rods and cotton swabs hitherto used.A single inoculation resulted in either no colonization of the duct, in temporary colonization for up to 7 days, or in colonization followed by intramammary infection.The recovery of the organisms depended on the size of the inoculum. When 70–100 CFU were placed in the teat duct no organisms were recovered from 12 of 24 quarters after the 1st post-inoculation milking. When 500–600 CFU were used, organisms were recovered from all of 31 quarters for at least 3 milkings, and from 61% for 6 milkings or more, in spite of dipping the teats in a strong disinfectant twice daily.Intramammary infection developed in 1 of 12 quarters (8%) inoculated in the teat duct with about 600 CFU when the animals were milked twice daily, and in 5 of 19 (23%) quarters if the 1st post-inoculation milking was omitted.There was no evidence of sensitization resulting from previous infection.


1993 ◽  
Vol 54 (2) ◽  
pp. 221-226 ◽  
Author(s):  
R. De la Fuente ◽  
J.A. Ruiz Santa Quiteria ◽  
D. Cid ◽  
M. Domingo ◽  
G. Suarez

2020 ◽  
Vol 87 (1) ◽  
pp. 82-88
Author(s):  
Cecilia M. Camussone ◽  
Ana I. Molineri ◽  
Marcelo L. Signorini ◽  
Verónica E. Neder ◽  
Carlos A. Vitulich ◽  
...  

AbstractThe aims of the research reported here were to identify potential risk factors associated with the presence of Staphylococcus aureus intramammary infection (IMI) in pre partum dairy heifers on 17 dairy farms from three provinces of Argentina and to characterize, at molecular level, isolates from those heifers and lactating cows from two selected herds. A total of 1474 heifers and 4878 lactating cows were studied. The prevalence of Staphylococcus aureus IMI in the heifers, heifers at quarter level and lactating cow mammary quarters was 14.41, 4.82, and 14.65%, respectively. Univariate analysis showed the key variables associated with S. aureus IMI presence in the heifers were: S. aureus IMI prevalence in cows of the lactating herd, the time calves stayed with their dam after birth, the calf rearing system, the place of rearing (own farm or other dairy farm) and fly control on the farm. None of the variables included in the multivariable analysis was associated with the presence of S. aureus IMI in the pre partum heifers, probably due to low variability among management practices used by the farms for rearing the heifer calves. At the molecular level, S. aureus isolates were grouped into three main PFGE clusters and several genotypes within the clusters. Isolates from mammary secretion of pre partum heifers and milk of lactating cows comprised different PFGE clusters in both herds, although two exceptions occurred. The absence of gene fnbpB, which codifies for a virulence factor protein involved in cell invasion by S. aureus, was significantly more frequent in pre partum heifer secretion isolates than in isolates from lactating cow milk. These results suggest that, under these management conditions, isolates from mammary secretions of pre partum heifers do not originate from the milk of lactating cows, but rather other sources to which the heifer is exposed.


2020 ◽  
Vol 9 (19) ◽  
Author(s):  
Soyoun Park ◽  
Dongyun Jung ◽  
Simon Dufour ◽  
Jennifer Ronholm

Staphylococcus aureus is one of the most common etiological agents responsible for contagious bovine mastitis. Here, we report the draft whole-genome sequences, with annotations, of 27 S. aureus strains and 3 Staphylococcus species strains that were isolated from Holstein cows with intramammary infection in Canada.


1997 ◽  
Vol 41 (5) ◽  
pp. 950-955 ◽  
Author(s):  
L Licata ◽  
C E Smith ◽  
R M Goldschmidt ◽  
J F Barrett ◽  
M Frosco

The postantibiotic subminimum inhibitory concentration effect (PA SME) may simulate in vivo drug exposure more accurately than the postantibiotic effect (PAE) since subinhibitory concentrations of drug persist between antibiotic dosings. In this study, we compared the PAEs and PA SMEs of levofloxacin and ciprofloxacin for clinical isolates of fluoroquinolone-susceptible Staphylococcus aureus and Streptococcus pneumoniae. At two times the MIC, PAEs of levofloxacin were an average of 0.6 h longer than the PAEs obtained for ciprofloxacin for methicillin-susceptible and methicillin-resistant S. aureus strains. The PAEs of levofloxacin and ciprofloxacin ranged from 1.8 to 3.1 and 1.1 to 2.4 h, respectively. Continued exposure of the methicillin-resistant strain to 1/16, 1/8, and 1/4 the MIC resulted in PA SMEs of 6.5, 15.3, and >22.3 h, respectively, for levofloxacin and 3.8, 8.0, and 12.3 h, respectively, for ciprofloxacin. For isolates of S. pneumoniae, at two times the MIC of both fluoroquinolones, the average PAEs of levofloxacin and ciprofloxacin were equivalent: 1.3 h for the penicillin-susceptible isolate and 0.6 h for the penicillin-resistant isolate. Continued exposure of the penicillin-susceptible S. pneumoniae strain to 1/16, 1/8, and 1/4 the MIC resulted in average PA SMEs of 1.0, 1.4, and 2.8 h, respectively, for levofloxacin and 1.8, 2.0, and 2.5 h, respectively, for ciprofloxacin. Continued exposure of penicillin-resistant S. pneumoniae to 1/16, 1/8, and 1/4 the MIC of the same fluoroquinolones resulted in average PA SMEs of 0.6, 1.1, and 2.9 h, respectively, for levofloxacin and 0.6, 1.1, and 1.5 h, respectively, for ciprofloxacin. The PA SMEs observed demonstrate the superior activity of levofloxacin against methicillin-susceptible or methicillin-resistant S. aureus. Although PAEs were similar for the penicillin-susceptible and penicillin-resistant S. pneumoniae strains, the PA SME of levofloxacin at one-fourth the MIC was longer for penicillin-resistant S. pneumoniae.


Phytomedicine ◽  
2010 ◽  
Vol 17 (5) ◽  
pp. 317-322 ◽  
Author(s):  
Manuela D’Arrigo ◽  
Giovanna Ginestra ◽  
Giuseppina Mandalari ◽  
P.M. Furneri ◽  
G. Bisignano

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