ABSTRACT
We evaluated the applicability of the LightCycler Staphylococcus M(GRADE0 assay on artificially infected blood samples from healthy donors and on clinical specimens of 31 hospitalized patients. The sensitivity and specificity of the assay for detecting Staphylococcus aureus was 100% in blood samples, and 100% in blood culture bottles, when data from the BACTEC 9120 blood culture system were taken as gold standard. The same specificity and sensitivity was found during the search for CoNS (Coagulase Negative Staphylococci) in blood culture bottles, whereas a 93.33% sensitivity and 100% specificity was observed for detecting CoNS directly in blood clinical specimens.
Subject(s)
Bacteremia/microbiology , Blood/microbiology , Equipment Contamination , Fluorescence Resonance Energy Transfer/methods , Polymerase Chain Reaction/methods , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Coagulase/analysis , Computer Systems , Culture Techniques/instrumentation , DNA, Bacterial/analysis , Humans , Nucleic Acid Denaturation , Polymerase Chain Reaction/instrumentation , Species Specificity , Staphylococcus aureus/enzymology , Staphylococcus aureus/genetics , Staphylococcus epidermidis/genetics , Staphylococcus haemolyticus/geneticsABSTRACT
There is continued interest in the development of oral beta-lactam compounds, which can be used clinically to treat various bacterial infections, particularly those caused by beta-haemolytic streptococci. Cefixime is a new orally active cephalosporin, with a broad spectrum of antibacterial activity, including Enterobacteriaceae, Haemophilus influenzae, Branhamella catarrhalis, Streptococcus pneumoniae and Streptococcus pyogenes. Cefixime is highly resistant to hydrolysis by most beta-lactamases. In this study the authors examined the effects of this molecule on Group A and Group B beta-haemolytic streptococci, recently isolated from clinical specimens in the authors' laboratory. MICs and the growth curves of 36 strains of Group A streptococci and the effects of sub-MICs on buccal cell adhesion were evaluated. The results show that concerning the sub-MIC cefixime effect on streptococci adherence, the treatment led to a decrease in adherence to the cells of the strains studied. Moreover cefixime showed good activity with 86.1% of the strains with MIC less than or equal to 0.5 microgram/ml, and the growth curves demonstrated that the molecule possesses a bactericidal effect after 3 h. Concerning Group B streptococci, 70.3% of the strains showed a MIC less than or equal to 2 micrograms/ml. In conclusion cefixime demonstrates good activity on beta-haemolytic streptococci, particularly those of Group A.
Subject(s)
Anti-Infective Agents, Urinary/pharmacology , Cefotaxime/analogs & derivatives , Streptococcus agalactiae/drug effects , Streptococcus pyogenes/drug effects , Cefixime , Cefotaxime/pharmacology , Cell Adhesion/drug effects , Cell Division/drug effects , Cheek , Dose-Response Relationship, Drug , Epithelial Cells , Epithelium/drug effects , Microbial Sensitivity Tests , Mouth Mucosa/cytology , Mouth Mucosa/drug effectsABSTRACT
In this study the in vitro antibacterial effects of cefixime are presented. Its activity was studied by evaluation of MICs, MBCs and the disc diffusion susceptibility method on Enterobacteriaceae, Staphylococcus aureus and Streptococcus pneumoniae. Moreover, the coefficient of correlation between MIC values and the disc diffusion susceptibility test was evaluated. The results support the wide antimicrobial activity of cefixime, which appears to be particularly effective against enterobacteria.
