scholarly journals Clinical implications of vancomycin susceptibility testing in Staphylococcus aureus

2013 ◽  
Vol 17 (2) ◽  
pp. 274
Author(s):  
Marcelo J. Mimica
2010 ◽  
Vol 23 (1) ◽  
pp. 99-139 ◽  
Author(s):  
Benjamin P. Howden ◽  
John K. Davies ◽  
Paul D. R. Johnson ◽  
Timothy P. Stinear ◽  
M. Lindsay Grayson

SUMMARY The emergence of vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) over the past decade has provided a challenge to diagnostic microbiologists to detect these strains, clinicians treating patients with infections due to these strains, and researchers attempting to understand the resistance mechanisms. Recent data show that these strains have been detected globally and in many cases are associated with glycopeptide treatment failure; however, more rigorous clinical studies are required to clearly define the contribution of hVISA to glycopeptide treatment outcomes. It is now becoming clear that sequential point mutations in key global regulatory genes contribute to the hVISA and VISA phenotypes, which are associated predominately with cell wall thickening and restricted vancomycin access to its site of activity in the division septum; however, the phenotypic features of these strains can vary because the mutations leading to resistance can vary. Interestingly, changes in the staphylococcal surface and expression of agr are likely to impact host-pathogen interactions in hVISA and VISA infections. Given the subtleties of vancomycin susceptibility testing against S. aureus, it is imperative that diagnostic laboratories use well-standardized methods and have a framework for detecting reduced vancomycin susceptibility in S. aureus.


2019 ◽  
Vol 109 ◽  
pp. 1809-1818 ◽  
Author(s):  
Saeed Khoshnood ◽  
Mohsen Heidary ◽  
Arezoo Asadi ◽  
Saleh Soleimani ◽  
Moloudsadat Motahar ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hend M. Abdulghany ◽  
Rasha M. Khairy

The current study aimed to use Coagulase gene polymorphism to identify methicillin-resistant Staphylococcus aureus (MRSA) subtypes isolated from nasal carriers in Minia governorate, Egypt, evaluate the efficiency of these methods in discriminating variable strains, and compare these subtypes with antibiotypes. A total of 400 specimens were collected from nasal carriers in Minia governorate, Egypt, between March 2012 and April 2013. Fifty-eight strains (14.5%) were isolated and identified by standard microbiological methods as MRSA. The identified isolates were tested by Coagulase gene RFLP typing. Out of 58 MRSA isolates 15 coa types were classified, and the amplification products showed multiple bands (1, 2, 3, 4, 5, and 8 bands). Coagulase gene PCR-RFLPs exhibited 10 patterns that ranged from 1 to 8 fragments with AluI digestion. Antimicrobial susceptibility testing with a panel of 8 antimicrobial agents showed 6 different antibiotypes. Antibiotype 1 was the most common phenotype with 82.7%. The results have demonstrated that many new variants of the coa gene are present in Minia, Egypt, different from those reported in the previous studies. So surveillance of MRSA should be continued.


Author(s):  
Ouattara Karamoko ◽  
Dibi Koffi Saint Didier ◽  
Kone Monon ◽  
Ouattara Abou ◽  
Bagre Issa

The emergence of infectious diseases, particularly staphylococcal infections, treatment failures and the more high cost of treatment of infections caused by resistant staphylococci called to find other care alternatives. This study was initiated to evaluate the antibacterial activity of the aqueous extract from Garcinia kola almonds on the in vitro growth of Staphylococcus aureus strains. The methods of diffusion in agar and liquid media were used for susceptibility testing and MIC and MBC determination. The tests were performed on four strains of S. aureus and one reference strain. The minimum inhibitory concentrations of the extracts ranged from 3.12 mg/mL and 12.5 mg/mL and the minimum bactericidal concentrations between 6.25 mg/mL and 25 mg/mL. The lowest value of MIC and MBC was observed with S. aureus ATCC 29213 while the greatest value of these same parameters was obtained on S. aureus 993C/18 and S. aureus 1075C/18. The aqueous almonds extract of Garcinia kola had a bactericidal activity on all the strains of S. aureus studied. This could justify the use of Garcinia kola almonds in the treatment of various diseases in traditional society.


2013 ◽  
Vol 58 (2) ◽  
pp. 1243-1247 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Robert K. Flamm ◽  
Patricia A. Hogan ◽  
James E. Ross ◽  
Ronald N. Jones

ABSTRACTThis study summarizes the linezolid susceptibility testing results for 7,429 Gram-positive pathogens from 60 U.S. sites collected during the 2012 sampling year for the LEADER Program. Linezolid showed potent activity when tested against 2,980Staphylococcus aureusisolates, inhibiting all but 3 at ≤2 μg/ml. Similarly, linezolid showed coverage against 99.5% of enterococci, as well as for all streptococci tested. These results confirm a long record of linezolid activity against U.S. Gram-positive isolates since regulatory approval in 2000.


1997 ◽  
Vol 64 (2) ◽  
pp. 253-260 ◽  
Author(s):  
TERHI ALI-VEHMAS ◽  
PETER WESTPHALEN ◽  
VESA MYLLYS ◽  
MARKUS SANDHOLM

The susceptibility to penicillin-G of Staphylococcus aureus strains that cause mastitis was tested in milk and in Iso-sensitest broth (ISB). The minimal inhibitory concentrations (MIC) of β-lactamase-positive strains in milk were 10–100-fold those in ISB, whereas the MIC of β-lactamase-negative strains in milk were some 10-fold those in ISB; β-lactamase production was induced by milk in β-lactamase-positive strains. Much of the increase in resistance to penicillin-G caused by milk can be attributed to milk fat globules; the increase in resistance was related to the binding capacity of the bacteria to milk fat globules as well as to capsule formation by the bacteria. It appears that the binding of the staphylococci to the fat globules and bacterial capsule formation resulted in a biofilm type of growth. In this case, the staphylococci behaved differently from the planktonic type of growth in artificial broth medium in which antibiotic susceptibility testing is usually carried out.


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