Characteristics of Adherence to Plastic Tissue Culture Plates of Coagulase-Negative Staphylococci Exposed to Subinhibitory Concentrations of Antimicrobial Agents

1988 ◽  
Vol 157 (1) ◽  
pp. 71-77 ◽  
Author(s):  
K. H. Schadow ◽  
W. A. Simpson ◽  
G. D. Christensen
1998 ◽  
Vol 42 (11) ◽  
pp. 2870-2876 ◽  
Author(s):  
P. Christian Lück ◽  
Jürgen W. Schmitt ◽  
Arne Hengerer ◽  
Jürgen H. Helbig

ABSTRACT We determined the MICs of ampicillin, ciprofloxacin, erythromycin, imipenem, and rifampin for two clinical isolates of Legionella pneumophila serogroup 1 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay and by quantitative culture. To test the influence of subinhibitory concentrations (sub-MICs) of antimicrobial agents on Legionella uptake into Acanthamoeba castellanii and U937 macrophage-like cells, both strains were pretreated with 0.25 MICs of the antibiotics for 24 h. In comparison to that for the untreated control, subinhibitory concentrations of antibiotics significantly reducedLegionella uptake into the host cells. Measurement of the binding of monoclonal antibodies against several Legionellaantigens by enzyme-linked immunoassays indicated that sub-MIC antibiotic treatment reduced the expression of the macrophage infectivity potentiator protein (Mip), the Hsp 60 protein, the outer membrane protein (OmpM), an as-yet-uncharacterized protein of 55 kDa, and a few lipopolysaccharide (LPS) epitopes. In contrast, the expression of some LPS epitopes recognized by monoclonal antibodies 8/5 and 30/4 as well as a 45-kDa protein, a 58-kDa protein, and the major outer membrane protein (OmpS) remained unaffected.


1964 ◽  
Vol 41 (4) ◽  
pp. 385-387
Author(s):  
R. C. Reynolds ◽  
Louise Stinson ◽  
Betty Hatten

2015 ◽  
Vol 59 (5) ◽  
pp. 2583-2587 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Nachum Kaplan ◽  
Ronald N. Jones ◽  
David J. Farrell

ABSTRACTStaphylococcus aureusand coagulase-negative staphylococci (CoNS) are responsible for a wide variety of human infections. The investigational antibacterial Debio1450 (previously AFN-1720), a prodrug of Debio1452 (previously AFN-1252), specifically targets staphylococci without significant activity against other Gram-positive or Gram-negative species. Debio1452 inhibits FabI, an enzyme critical to fatty acid biosynthesis in staphylococci. The activity of Debio1452 against CoNS, methicillin-susceptibleS. aureus(MSSA), and methicillin-resistantS. aureus(MRSA), including significant clones, was determined. A globally diverse collection of 574 patient isolates from 35 countries was tested that included CoNS (6 species, 103 strains), MSSA (154 strains), MRSA (163 strains), and molecularly characterized strains (includingspa-typed MRSA clones; 154 strains). The isolates were tested for susceptibility by CLSI broth microdilution methods against Debio1452 and 10 comparators. The susceptibility rates for the comparators were determined using CLSI and EUCAST breakpoint criteria. AllS. aureusand CoNS strains were inhibited by Debio1452 concentrations of ≤0.12 and ≤0.5 μg/ml, respectively. The MIC50s for MSSA, MRSA, and molecularly characterized MRSA strains were 0.004 μg/ml, and the MIC90s ranged from 0.008 to 0.03 μg/ml. The MICs were higher for the CoNS isolates (MIC50/90, 0.015/0.12 μg/ml). AmongS. aureusstrains, resistance was common for erythromycin (61.6%), levofloxacin (49.0%), clindamycin (27.6%), tetracycline (15.7%), and trimethoprim-sulfamethoxazole (7.0%). Debio1452 demonstrated potent activity against MSSA, MRSA, and CoNS. Debio1452 showed significantly greater activity overall (MIC50, 0.004 μg/ml) than the other agents tested against these staphylococcal species, which included dominant MRSA clones and strains resistant to currently utilized antimicrobial agents.


1988 ◽  
Vol 8 (4) ◽  
pp. 277-279
Author(s):  
Wendy L. Vaudry ◽  
Claudia Gratton ◽  
Kinga Kowalewska ◽  
Wanda M. Wenman

The minimum inhibitory concentration (MIC) of daptomycin was compared with that of four other antimicrobial agents against clinically relevant staphylococci. Sixtyfive isolates were obtained from patients on continuous ambulatory peritoneal dialysis (CAPD) who contracted peritonitis. These isolates comprised 29 S. Sureus strains (all sensitive to oxacillin); 25 S. epidermidis strains (14 sensitive and 9 resistant to oxacillin); and 11 unspeciated coagulase-negative staphylococci (2 sensitive and 11 resistant to oxacillin). All of the oxacillin susceptible strains were inhibited by ≤2 mg/L of the five antibiotics tested. The oxacillin resistant staphylococci were also resistant to cefuroxime and variably resistant to cefamandole, but were uniformly susceptible to both vancomycin and daptomycin. Daptomycin possesses equivalent in vitro activity to vancomycin against strains of S. Sureus and coagulase negative staphylococci associated with CAPD peritonitis. If vancomycin resistance becomes a significant problem in these patients, and daptomycin is shown to be active against vancomycin resistant organisms, then it would have potential usefulness as an alternative to vancomycin in the treatment of peritonitis caused by multiply -resistant staphylococci.


2019 ◽  
Vol 53 (5) ◽  
pp. 351-354
Author(s):  
Carla Moraes ◽  
Camila Q.M. Bruna ◽  
Cristiane de Lion Botero Couto Lope ◽  
Kazuko U. Graziano

Abstract Currently, there are two orthopedic implant types: (1) Sterile implants (e.g., joint prostheses) are distributed in a ready-for-use sterile fashion, and (2) nonsterile implants (e.g., plates, screws, Schanz pins, intramedullary rods) are processed by a healthcare facility's central sterile service department (CSSD). The current study evaluated processed implants for presence of coagulase-negative staphylococci, which was observed in 30% of the cortical screws, spongy screws, and Schanz pins (37 total samples) processed by a CSSD. Some samples were resistant to antimicrobial agents, thereby demonstrating that risk exists in the current methods used in the processing of nonsterile implants. Also of important note, nonsterile implants are commonly loaned worldwide. Loaned implantable materials should not be processed in the same manner as materials routinely prepared in the CSSD, as it is not possible to know the quality of the cleaning performed before the materials are returned to the loaning company. It is not uncommon for hospitals to receive loaned materials with organic residues.


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