Susceptibility patterns of coagulase-negative staphylococci to several newer antimicrobial agents in comparison with vancomycin and oxacillin (original) (raw)
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In vitro study to evaluate the sensitivity to daptomycin among gram positive clinical isolates
Indian Journal of Medical Microbiology, 2012
Sr. No. Title Page No. 1. Abbreviations vii-viii 2. Distribution list (Controlled copies) ix 3. Amendment sheet x 4. Chapter 1: General guidelines 1-13 5. Chapter 2: Specimen collection, transport & processing Blood CSF Body fluids Ocular specimens Respiratory specimens Pus Urine Fecal specimen Tissue 15-47 6. Chapter 3: Identification of isolates Enterobacteriaceae Salmonella Stenotrophomonas maltophilia, Burkholderia cepacia complex Pseudomonas Acinetobacter Staphylococci Enterococci Fecal isolates Streptococcus sp (beta and alpha hemolytic) Streptococcus pneumoniae 49-77 7. Chapter 4: Antimicrobial Susceptibility Testing Definitions Disc diffusion testing ATCC control strains Preparing antibiotic discs in-house Minimum Inhibitory Concentration (MIC) testing Zone diameters and MIC breakpoints 79-103 8. Chapter 5: Special Tests (Phenotypic) Carba-NP test (For Enterobacteriaceae and Pseudomonas spp.) Modified carbapenem inactivation method (mCIM and eCIM); (For Enterobacteriaceae and Pseudomonas spp.) D-test for inducible clindamycin resistance Vancomycin screen agar for S. aureus and Enterococcus spp. MIC for vancomycin by broth micro dilution method Detection of heteroresistant vancomycin intermediate Staphylococcus aureus (hVISA) population analysis profile/area under curve (PAP/AUC) analysis Combination antimicrobial testing to evaluate the best combination of drugs for MRSA Detection of over-expression of efflux pumps MIC 105-113 9. Chapter 6: Quality control (QC) Reference strains for QC Storing and testing QC strains Frequency of testing Quality control of media
PLoS ONE, 2014
Objective: The main objective of this study was to comparatively evaluate the performance of M.I.C.E. and Etest methodologies to that of agar dilution for determining the antimicrobial susceptibility profile of oxacillin-resistant Staphylococcus spp. Methods: A total of 100 oxacillin-resistant Staphylococcus spp. isolates were collected from hospitalized patients at a teaching hospital. Antimicrobial susceptibility testing for vancomycin, teicoplanin and linezolid was performed using the reference CLSI agar dilution method (2009), Etest and M.I.C.E. methodologies. The MIC values were interpreted according to CLSI susceptibility breakpoints and compared by regression analysis. Results: In general, the essential agreement (61-log 2) between M.I.C.E. and CLSI agar dilution was 93.0%, 84.0% and 77.0% for linezolid, teicoplanin and vancomycin, respectively. Essential agreement rates between M.I.C.E. and Etest were excellent (.90.0%) for all antibiotics tested. Both strips (M.I.C.E. and Etest) yielded two very major errors for linezolid. Unacceptable minor rates were observed for teicoplanin against CoNS and for vancomycin against S. aureus. Conclusions: According to our results, linezolid and teicoplanin MICs against all staphylococci and S. aureus, respectively, were more accurately predicted by M.I.C.E. strips. However, the Etest showed better performance than M.I.C.E. for predicting vancomycin MICs against all staphylococci. Thus, microbiologists must be aware of the different performance of commercially available gradient strips against staphylococci.
A multicentre study:Staphylococcus andEnterococcus susceptibility to antibiotics
European Journal of Epidemiology, 1994
A multicentre study to evaluate the susceptibility of Gram-positive cocci isolated from clinical samples, was performed by six centres working in different areas of Italy. We examined 4,544 strains of Staphylococcus aureus, 4,381 strains of coagulase-negative staphylococci and 2,478 strains of enterococci. The following antibiotics were tested: penicillin G, ampicillin, amoxicillin, piperacillin, imipenem, oxacillin, ofloxacin, pefloxacin, ciproftoxacin, gentamicin, tobramycin, amikacin, netilmicin, rifampicin, clindamycin, tetracycline, cotrimoxazole, erythromycin, chloramphenicol, vancomycin and teicoplanin. Oxacillin-susceptible staphylococci confirmed their susceptibility to many other anti-microbial agents while oxacillin-resistant strains confirmed their multiple and frequent resistance to antibiotics. Resistance to oxacillin, cotrimoxazole and chloramphenicol was more frequent in coagulase-negative staphylococci than in Staphylococcus aureus. Aminoglycosides, rifampicin and quinolones were more active against coagulase-negative staphylococci than against Staphylococcus aureus. Enterococci were susceptible to penicillins and imipenem, and moderately susceptible to ciprofloxacin. Susceptibility of 70-79% was observed with high levels of aminoglycosides. Excellent results against staphylococci and enterococci were observed with vancomycin and teicoplanin.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2011
The activity of beta-lactam antibiotics (oxacillin, cloxacillin, cephalotin), vancomycin, gentamicin and rifampicin applied in vitro individually and in combination against 37 nosocomial methicillin-resistant strains of coagulase-negative staphylococci (CNS) was assessed to demonstrate the heterogeneity of this group of bacteria and estimate the chance of the efficacy of such therapy. The strains belonged to four species: Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus cohnii, Staphylococcus hominis. They originated from a hospital environment and from the skin of medical staff of the intensive care unit of a paediatric ward at a university hospital. All strains were methicillin-resistant, according to CLSI standards, but individual strains differed in MIC(ox) values. Susceptibility to other tested antibiotics was also characteristic for the species. The increased susceptibility to antibiotics in combinations, tested by calculating the fractional inhibitory c...
Microbial Drug Resistance, 2003
We assessed the in vitro activities of daptomycin, linezolid, and quinupristin-dalfopristin (QD) against a contemporary challenge panel of 88 staphylococcal and 90 enterococcal isolates. The staphylococci selected included vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant S. aureus, and coagulasenegative staphylococci. Enterococcal isolates included vancomycin-resistant Enterococcus faecium (VREF) containing either vanA, vanB1, or vanD. The MICs of daptomycin, linezolid, and QD were determined using commercial broth microdilution panels. All three VISA isolates were susceptible to daptomycin, linezolid, and QD. QD was the most active agent against staphylococcal isolates (MIC 50 # 0.5 mg/ml and MIC 90 5 1 mg/ml), including those with decreased susceptibility to vancomycin. QD was also the most active agent against VREF (MIC 90 # 0.5 mg/ml). No differences were seen for susceptibility of vanA, vanB1, and vanD VREF strains for daptomycin, linezolid, or QD. Daptomycin was the most effective against E. faecalis. On the basis of manufacturer-suggested interpretive criteria, 92% of isolates were susceptible (MIC 90 5 4 mg/ml). All isolates tested were susceptible to at least one antimicrobial agent for which interpretive criteria have been defined. Population analysis of three S. aureus isolates for which the daptomycin MICs were 8 mg/ml showed a pattern of homogeneous resistance.