scholarly journals Species-Specific Sensitivity of Coagulase-Negative Staphylococci to Single Antibiotics and Their Combinations

2011 ◽  
Vol 60 (2) ◽  
pp. 155-161 ◽  
Author(s):  
GRAŻYNA SZYMAŃSKA ◽  
MAGDALENA SZEMRAJ ◽  
ELIGIA M. SZEWCZYK
Keyword(s):  
University Hospital ◽  
Hospital Environment ◽  
Beta Lactam ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics ◽  
Resistant Strains ◽  
Staphylococcus Hominis ◽  
Species Specific

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 concentration (FIC) index, concerned 26 out of 37 investigated strains and it was a feature of a particular species. Combinations of vancomycin and cephalotin against S. epidermidis and oxacillin with vancomycin were significant, as well as cephalotin and rifampicin in growth inhibition of multiresistant S. haemolyticus strains.

scholarly journals Prevalence and characteristics of methicillin-resistant staphylococci in goats on the island of Tenerife, Spain

2019 ◽  
Vol 67 (3) ◽  
pp. 317-326
Author(s):  
Rossana Abreu ◽  
Cristobalina Rodríguez-Álvarez ◽  
María Lecuona ◽  
Beatriz Castro-Hernández ◽  
Juan Carlos González ◽  
...  
Keyword(s):  
Control Measures ◽  
Animal Origin ◽  
Beta Lactam ◽  
Coagulase Negative Staphylococci ◽  
Cross Sectional ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics ◽  
Resistance Patterns ◽  
Erythromycin A ◽  
Genotypic Characteristics

The aim of this study was to determine the prevalence of methicillin-resistant Staphylococcus (MRS) in healthy goats on the Island of Tenerife, Spain, as well as to identify the phenotypic and genotypic characteristics of the strains found. A cross-sectional prevalence study was conducted. A total of 158 goats from 15 different farms were sampled between September 2017 and January 2018. The percentage of positive samples of methicillin-resistant Staphylococcus aureus (MRSA) was 15.8% (25/158) and that of methicillin-resistant coagulase-negative staphylococci (MRCoNS) was 6.9% (11/158). All MRSA isolates from goats belonged to one clonal group showing Multi-Locus Sequence type 398. All strains studied (n = 36) were resistant to non-carbapenem beta-lactam antibiotics and susceptible to teicoplanin, linezolid, vancomycin, rifampicin, quinupristin-dalfospristin and mupirocine. In MRSA isolates, the highest percentage of resistance obtained, besides beta-lactam non-carbapenem antibiotics, was to trimethoprim-sulphamethoxazole and, in the case of MRCoNS isolates, to phosphomycin and erythromycin. A total of 12 resistance patterns were obtained, presenting differences between patterns obtained for MRSA and MRCoNS, with 7 different patterns for MRSA and 5 for MRCoNS. We therefore consider it essential to expand the epidemiological study of these strains of animal origin, as well as to increase surveillance and control measures at all stages of the food chain.

scholarly journals Missense Mutations in PBP2A Affecting Ceftaroline Susceptibility Detected in Epidemic Hospital-Acquired Methicillin-Resistant Staphylococcus aureus Clonotypes ST228 and ST247 in Western Switzerland Archived since 1998

2015 ◽  
Vol 59 (4) ◽  
pp. 1922-1930 ◽  
Author(s):  
William L. Kelley ◽  
Ambre Jousselin ◽  
Christine Barras ◽  
Emmanuelle Lelong ◽  
Adriana Renzoni
Keyword(s):  
Staphylococcus Aureus ◽  
University Hospital ◽  
Surveillance Program ◽  
Missense Mutations ◽  
Unknown Parameters ◽  
Methicillin Resistant ◽  
Content Type ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACTThe development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistantStaphylococcus aureus(MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested thein vitroactivity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed ceftaroline-resistant strains (MIC, >1 μg/ml in 40/60 strains; EUCAST breakpoints, susceptible [S], ≤1 μg/ml; resistant [R], >1 μg/ml) were present from 1998 to 2003. The detected resistant strains predominantly belonged to sequence type 228 (ST228) (South German clonotype) but also to ST247 (Iberian clonotype). A sequence analysis of these strains revealed missense mutations in the penicillin-binding protein 2A (PBP2A) allosteric domain (N146K or E239K and N146K-E150K-G246E). The majority of our ST228 PBP2A mutations (N146K or E150K) were distinct from ST228 PBP2A allosteric domain mutations (primarily E239K) recently described for MRSA strains collected in Thailand and Spain during the 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance program. We also found that similar allosteric domain PBP2A mutations (N146K) correlated with ceftaroline resistance in an independent external ST228 MRSA set obtained from the nearby University Hospital of Lausanne, Lausanne, Switzerland, collected from 2003 to 2008. Thus, ceftaroline resistance was observed in our archived strains (including two examples of an MIC of 4 µg/ml for the Iberian ST247 clonotype with the triple mutation N146K/E150K/G246E), at least as far back as 1998, considerably predating the commercial introduction of ceftaroline. Our results reinforce the notion that unknown parameters can potentially exert selective pressure on PBP2A that can subsequently modulate ceftaroline resistance.

Antibiotic Resistance: Relationship to Persistence of Group A Streptococci in the Upper Respiratory Tract

PEDIATRICS ◽  
1996 ◽  
Vol 97 (6) ◽  
pp. 971-975
Author(s):  
Michael A. Gerber
Keyword(s):  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Beta Lactam ◽  
Erythromycin Resistance ◽  
In Vitro Susceptibility ◽  
Beta Lactam Antibiotics ◽  
Group A ◽  
Resistant Strains ◽  
Upper Respiratory

Despite the use of penicillin for more than 40 years in treating GABHS infections, there has been no significant change in the in vitro susceptibility of GABHS to penicillin. Reported failures to eradicate GABHS from the upper respiratory tracts of patients with pharyngitis and the apparent resurgence of serious Group A streptococcal infections and their sequelae probably are not related to the emergence of penicillin resistance. Although erythromycin resistance in GABHS had been a major problem in Japan and continues to be a major problem in Finland, it has not been a problem in this country. The susceptibility of GABHS to the newer macrolide antibiotics appears to be similar to that of erythromycin. Comprehensive, community-wide programs to continuously monitor for erythromycin resistance in GABHS would be difficult to justify. However, because little is known about how erythromycin resistance in GABHS is acquired or spread, it would be reasonable to periodically monitor isolates of GABHS for erythromycin resistance. A substantial proportion of GABHS are currently resistant to tetracyclines and these agents are inappropriate for treating GABHS infections. Although little recent information is available about the susceptibility of GABHS to sulfonamides, these agents have been shown to be ineffective in eradicating GABHS from the upper respiratory tract regardless of the in vitro sensitivities. GABHS have not been shown to be resistant to any of the commonly used oral cephalosporins; however, there is a great deal of variability among these agents in their activity against GABHS. Clindamycin resistance in GABHS has remained unusual. This agent is an alternative for treating GABHS infections due to macrolide-resistant strains in patients who cannot be treated with beta-lactam antibiotics. There is no reason, based on the in vitro susceptibilities of GABHS, to change the current recommendations for treating GABHS infections with penicillin and for using erythromycin for patients who are allergic to penicillin.

scholarly journals In vitro evaluation of BO-3482, a novel dithiocarbamate carbapenem with activity against methicillin-resistant staphylococci.

1997 ◽  
Vol 41 (10) ◽  
pp. 2282-2285 ◽  
Author(s):  
Y Adachi ◽  
K Nakamura ◽  
Y Kato ◽  
N Hazumi ◽  
T Hashizume ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clostridium Difficile ◽  
Proteus Mirabilis ◽  
Gram Negative Bacteria ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics

BO-3482, a dithiocarbamate carbapenem, inhibited clinical isolates of methicillin-resistant staphylococci (MRS) at 6.25 microg/ml (MIC at which 90% of isolates tested are inhibited [MIC90]), while the MIC90 of imipenem was > 100 microg/ml. BO-3482 was generally less active than imipenem against methicillin-susceptible Staphylococcus aureus, streptococci, enterococci, and gram-negative bacteria, although BO-3482 showed better activity (MIC90) than imipenem against Enterococcus faecium, Haemophilus influenzae, Proteus mirabilis, and Clostridium difficile. The affinities (50% inhibitory concentrations) of BO-3482 for penicillin-binding protein (PBP) PBP 2' of MRS and PBP 5 of E. faecium (both PBPs have low affinities for ordinary beta-lactam antibiotics) were 3.8 and 20 microg/ml, respectively, reflecting the greater activity of BO-3482 against MRS than against E. faecium.

scholarly journals Methicillin-resistant staphylococci.

1988 ◽  
Vol 1 (2) ◽  
pp. 173-186 ◽  
Author(s):  
H F Chambers
Keyword(s):  
Methicillin Resistance ◽  
Test Methods ◽  
Beta Lactam ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics ◽  
Heterogeneous Expression ◽  
Extreme Variability ◽  
Resistance Trait ◽  
Resistant Strains ◽  
High Concentrations

Strains of staphylococci resistant to methicillin were identified immediately after introduction of this drug. Methicillin-resistant strains have unusual properties, the most notable of which is extreme variability in expression of the resistance trait. The conditions associated with this heterogeneous expression of resistance are described. Methicillin resistance is associated with production of a unique penicillin-binding protein (PBP), 2a, which is bound and inactivated only at high concentrations of beta-lactam antibiotics. PBP2a appears to be encoded by the mec determinant, which also is unique to methicillin-resistant strains. The relationships between PBP2a and expression of resistance and implications for the mechanism of resistance are discussed. The heterogeneous expression of methicillin resistance by staphylococci poses problems in the detection of resistant strains. Experience with several susceptibility test methods is reviewed and guidelines for performance of these tests are given. Treatment of infections caused by methicillin-resistant staphylococci is discussed. Vancomycin is the treatment of choice. Alternatives have been few because methicillin-resistant strains often are resistant to multiple antibiotics in addition to beta-lactam antibiotics. New agents which are active against methicillin-resistant staphylococci are becoming available, and their potential role in treatment is discussed.

In vitro activity of dalbavancin and other anti-staphylococcal agents against infecting isolates of methicillin-resistant coagulase-negative staphylococci

2021 ◽  
Vol 70 (9) ◽  
Author(s):  
Maria Plota ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Fevronia Kolonitsiou ◽  
Ekaterini Tsiata ◽  
Iris Spiliopoulou ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
University Hospital ◽  
Soft Tissue Infections ◽  
In Vitro Activity ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
European Committee

Introduction. Dalbavancin was approved in Europe in 2015 for skin and soft tissue infections. Hypothesis/Gap Statement. Data on methicillin-resistant coagulase-negative staphylococci (MR-CNS) dalbavancin susceptibility are scarce. Aim. To assess the susceptibility of MR-CNS to dalbavancin and other anti-staphylococcal agents. Methodology. A total of 443 MR-CNS clinical isolates from patients hospitalized in a Greek university hospital during a 2.5-year period (January 2018 to June 2020) were included. The MICs for vancomycin, teicoplanin, linezolid and daptomycin were investigated by Etest and the MIC for dalbavancin was determined according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines in 196 isolates. The consumption of the aforementioned antimicrobials was calculated. Results. In total, 51 isolates were resistant to teicoplanin (11.5 %) and 211 (47.6 %) to linezolid; all were susceptible to vancomycin and daptomycin. Among 196 isolates tested, 32 (16.3 %) were resistant to dalbavancin. A significant increase of MIC during the study period was found for vancomycin, teicoplanin and daptomycin, while a decrease in linezolid’s MIC was observed. Dalbavancin’s MIC remained stable. No difference in consumption was observed among the studied anti-staphylococcal agents. Conclusion. An increase of vancomycin, teicoplanin and daptomycin MICs among MR-CNS was observed, whereas 47.6 % of isolates were non-susceptible to linezolid. Dalbavancin retains excellent potency against MR-CNS, even in the presence of non-susceptibility to other anti-staphylococcal antibiotics.

scholarly journals Involvement of a 43-kilodalton outer membrane protein in beta-lactam resistance of Shigella dysenteriae.

1997 ◽  
Vol 41 (10) ◽  
pp. 2302-2304 ◽  
Author(s):  
A K Kar ◽  
A S Ghosh ◽  
K Chauhan ◽  
J Ahamed ◽  
J Basu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Shigella Dysenteriae ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Beta Lactam Antibiotics ◽  
Resistant Strains

A beta-lactam-sensitive strain (C152) of Shigella dysenteriae showed two major outer membrane proteins (OMPs) with M(r)s of 43,000 and 38,000, while the clinical isolate M2 lacked the 43,000-Mr OMP, which acted as a channel for beta-lactam antibiotics. Permeability of beta-lactams across the outer membrane (OM) of M2 was lower than that across the OM of C152. Mutants deficient in the 43-kDa OMP could be selected in vitro from strain C152 in the presence of cefoxitin. All beta-lactam-resistant strains were sensitive to imipenem.

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