scholarly journals Detection of vancomycin-resistant enterococci using chromogenic selective medium

2018 ◽  
Vol 20 (1) ◽  
pp. 55-61
Author(s):  
Anastasiya V. Fyodorova ◽  
Galina A. Klyasova
Keyword(s):  
Blood Culture ◽  
High Sensitivity ◽  
Selective Medium ◽  
Vana Gene ◽  
Microdilution Method ◽  
Vancomycin Resistant Enterococci ◽  
Broth Microdilution Method ◽  
Enterococcus Spp ◽  
Rectal Swabs ◽  
Vancomycin Resistant

Objective. To detect vancomycin-resistant enterococci (VRE) using chromogenic selective medium CHROMagar™VRE (CHROMagar, France). Materials and Methods. In the first part of the study, a total of 39 vancomycin-resistant and 20 vancomycinsusceptible Enterococcus spp. isolated from blood culture with known susceptibility profiles were incubated on the CHROMagar™VRE (CHROMagar, France) and examined after 24 h and 48 h of incubation. In the second part of the study, a total of 110 rectal swabs were taken from patients with hematological malignancies and incubated on the CHROMagar™VRE. The vancomycin susceptibility of isolates grown on the selective medium was further evaluated by the broth microdilution method (CLSI, 2017). Glycopeptide resistance genes were detected by PCR. Results. Using the CHROMagar™VRE, a total of 36 (92.3%) vancomycin-resistant isolates were detected after 24 h and additional two isolates – after 48 h of incubation. The sensitivity of the selective medium for detection of VRE obtained from blood culture was 92% and 97% after 24 h and 48 h of incubation, respectively. All 20 vancomycin-susceptible enterococci did not grow on the CHROMagar™VRE (specificity – 100%). Of 110 rectal swabs, 35 (31.8%) samples were positive for Enterococcus spp. on the CHROMagar™VRE (33 – E. faecium и 2 – E. faecalis). Resistance to vancomycin was detected in 32⁄33 (97%) E. faecium isolates, of them 28 and 4 strains were isolated after 24 h and 48 h of incubation; all VRE strains carried vanA gene. The proportion of false positive isolates was 3.4% after 24 h of incubation and 8.6% after 48 h of incubation on the CHROMagar™VRE medium for screening of VRE from rectal swabs. Conclusions. The chromogenic selective media CHROMagar™VRE has a high sensitivity and specificity for the detection of VRE and can be used for screening in laboratory practice.

scholarly journals Antimicrobial resistance of nosocomial Enterococcus spp. isolated from blood culture in patients with hematological malignancies

2018 ◽  
Vol 20 (2) ◽  
pp. 142-149
Author(s):  
Galina A. Klyasova ◽  
Anastasiya V. Fyodorova ◽  
I.N. Frolova ◽  
Svetlana A. Khrulnova ◽  
A.V. Vetokhina ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Hematological Malignancies ◽  
Resistant Isolate ◽  
23S Rrna ◽  
Vana Gene ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Enterococcus Spp ◽  
Vancomycin Resistant

Objective. To evaluate antimicrobial susceptibility of Enterococcus spp. isolated from blood culture in patients with hematological malignancies. Materials and Methods. Antimicrobial susceptibility of 427 Enterococcus spp. collected from 10 hospitals in 8 cities of Russia in 2002-2016 as part of the multicenter study was tested by the broth microdilution method [CLSI 2015]. Results. Among bloodstream pathogens there was a prevalence of E. faecium (78.2%), followed by E. faecalis (19.7%) and other Enterococcus spp. (2.1%). A total of 50 (15%) vancomycin-resistant E. faecium (Vancomycin-resistant Enterococcus – VRE) was detected, of them 33 (66%) were harboring vanA gene, 17 (34%) – vanB gene. In 2012 one linezolid resistant E. faecium (MIC = 16 µg/mL) was detected. Linezolid-resistant E. faecium contained the G2576T 23S rRNA mutation. All VRE faecium including the one linezolid-resistant isolate were susceptible to daptomycin. All E. faecium were susceptible to tigecycline, 78.7% – to chloramphenicol, 74.9% – to tetracycline. Proportion of E. faecium with high level resistance to gentamicin was 85%, to streptomycin – 60%, to both aminoglycosides – 45%. All E. faecalis were susceptible to linezolid, teicoplanin and tigecycline; 97.6% – to ampicillin. One isolate of E. faecalis (1.2%) with intermediate susceptibility to vancomycin (MIC = 16 µg/mL) harboring vanD gene and one isolate of E. gallinarum resistant to vancomycin, carrying vanC1 and vanB genes were detected. Conclusions. Isolates of E. faecalis had more favorable profile of antimicrobial susceptibility comparing to E. faecium. A total of 15% E. faecium were vancomycin resistant and one of them had resistance to linezolid. In this study one E. faecalis and one E. gallinarum isolates were non-susceptible to vancomycin.

scholarly journals In vitro efficacy of vancomycin combined with fosfomycin against Vancomycin-Resistant Enterococci strains

2019 ◽  
Vol 36 (2) ◽  
Author(s):  
Gulseren Aktas
Keyword(s):  
Inhibitory Concentration ◽  
Distinct Advantage ◽  
Creative Commons ◽  
Microdilution Method ◽  
Vancomycin Resistant Enterococci ◽  
Broth Microdilution Method ◽  
Vancomycin Resistant ◽  
Time Kill ◽  
Open Access Article

Objective: Enterococci have been isolated frequently worldwide and have difficulties in the treatment. Combination antibiotherapies have a distinct advantage over monotherapies in terms of their synergistic effect. In the study, it was aimed to investigate in vitro activity of vancomycin combined with fosfomycin against VRE strains. Methods: A total of 30 VRE strains were included in the study. Bacterial identifications of the strains were undertaken using conventional routine methods. The resistance to agents tested was investigated by using the broth microdilution method. Glucose-6-phosphate (25 mcg/mL) for fosfomycin were used in all experiments. The activity of antibiotics in combination was assessed using a broth microcheckerboard. The fractional inhibitory concentration index (FICI) was interpreted as follows: synergism, FICI ≤0.5. Additionally, two strains in 30 VRE were studied to determine the time-kill curves to verify the synergistic results. For each strain, antibiotics were studied alone and in combination at the minimum inhibitory concentration (1xMIC) values. Results: Susceptibility rate to fosfomycin was found at 26.6 % (8/30). The MIC50, MIC90 and MIC interval values of antimicrobials were 512, 512, and 512 - 1024 mcg/mL for vancomycin, and 128, 160, and 64 - 224 mcg/mL for fosfomycin, respectively. The rate of synergism was found as 100 % by both checkerboard and time-kill methods. Conclusion: The result shows that the combination of vancomycin with fosfomycin could be an alternative in the treatment of infections caused by VRE. doi: https://doi.org/10.12669/pjms.36.2.1347 How to cite this:Aktas G. In vitro efficacy of vancomycin combined with fosfomycin against Vancomycin-Resistant Enterococci strains. Pak J Med Sci. 2020;36(2):281-285. doi: https://doi.org/10.12669/pjms.36.2.1347 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Characterization of a vancomycin-resistant Enterococcus faecium isolate and a vancomycin-susceptible E. faecium isolate from the same blood culture

2020 ◽  
Author(s):  
Kyriaki Xanthopoulou ◽  
Julia Wille ◽  
Janine Zweigner ◽  
Kai Lucaßen ◽  
Thorsten Wille ◽  
...  
Keyword(s):  
Blood Culture ◽  
Enterococcus Faecium ◽  
Core Genome ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Vana Gene ◽  
Plasmid Analysis ◽  
Vancomycin Resistant ◽  
Faecium Isolate

Abstract Objectives To characterize two Enterococcus faecium isolates with different resistance phenotypes obtained from the same blood culture. Methods The isolates were identified by MALDI-TOF MS and antimicrobial susceptibility testing (AST) was performed using a VITEK® 2 AST P592 card and Etest. WGS was performed on the MiSeq and MinION sequencer platforms. Core-genome MLST (cgMLST) and seven-loci MLST were performed. Plasmid analysis was performed using S1-PFGE followed by Southern-blot hybridization. Results Both E. faecium isolates were ST203. AST revealed that one was a vancomycin-resistant E. faecium (VREfm) isolate and the other was a vancomycin-susceptible E. faecium (VSEfm) isolate. The VREfm isolate harboured the vanA gene cluster as part of a Tn1546-type transposon encoded on a 49 kb multireplicon (rep1, rep2 and rep7a) plasmid (pAML0157.1). On the same plasmid, ant(6)-Ia, cat-like and erm(B) were encoded. The VSEfm isolate harboured a rep2 plasmid (pAML0158.1), 12 kb in size, which was present in full length as part of pAML0157.1 from the VREfm isolate. The vanA-encoding pAML0157.1 was a chimera of the rep2 pAML0158.1 and a second DNA segment harbouring vanA, ant(6)-Ia, erm(B) and cat-like, as well as the replicons rep1 and rep7a. By cgMLST analysis, the VREfm and VSEfm isolates were identical. Conclusions Our results demonstrate that the VREfm and VSEfm blood culture isolates represented ST203 and were identical. The investigated heterogeneous resistance phenotypes resulted from the acquisition or loss of plasmid segments in the enterococcal isolates. These data illustrate that mobile genetic elements may contribute to the spread of vancomycin resistance among enterococci and to the genotypic and phenotypic variation within clonal isolates.

scholarly journals Antimicrobial Susceptibility of 6685 Organisms Isolated from Canadian Hospitals: CANWARD 2007

2009 ◽  
Vol 20 (suppl a) ◽  
pp. 20A-30A
Author(s):  
George G Zhanel ◽  
Mel DeCorby ◽  
Kim A Nichol ◽  
Aleksandra Wierzbowski ◽  
Patricia J Baudry ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Methicillin Resistant ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Testing Susceptibility ◽  
Polymyxin E ◽  
Vancomycin Resistant ◽  
Gram Positive Cocci

BACKGROUND: Antimicrobial resistance is a growing problem in North American hospitals as well as hospitals worldwide. OBJECTIVES: To assess the antimicrobial susceptibility patterns of commonly used agents against the 20 most common organisms isolated from Canadian hospitals. METHODS: In total, 7881 isolates were obtained between January 1, 2007, and December 31, 2007, from 12 hospitals across Canada as part of the Canadian Ward Surveillance Study (CANWARD 2007). Of these, 6685 isolates (20 most common organisms) obtained from bacteremic, urinary, respiratory and wound specimens underwent antimicrobial susceptibility testing. Susceptibility testing was assessed using the Clinical and Laboratory Standards Institute broth microdilution method. RESULTS: The most active (based upon minimum inhibitory concentration [MIC] data only) agents against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) were dalbavancin, daptomycin, linezolid, telavancin, tigecycline and vancomycin, with MICs required to inhibit the growth of 90% of organisms (MIC90) of 0.06 μg/mL and 0.06 μg/mL, 0.25 μg/mL and 0.25 μg/mL, 4 μg/mL and 1 μg/mL, 0.25 μg/mL and 0.25 μg/mL, 0.5 μg/mL and 0.25 μg/mL, and 1 μg/mL and 2 μg/mL, respectively. The most active agents against vancomycin-resistant enterococci were daptomycin, linezolid and tigecycline with MIC90sof 2 μg/mL, 4 μg/mL and 0.12 μg/mL, respectively. The most active agents againstEscherichia coliwere amikacin, cefepime, ertapenem, meropenem, piperacillin-tazobactam and tigecycline with MIC90sof 4 μg/mL, 2 μg/mL, 0.06 μg/mL or less, 0.12 μg/mL or less, 4 μg/mL and 1 μg/mL, respectively. The most active agents against extendedspectrum beta-lactamase-producing E coli were ertapenem, meropenem and tigecycline with MIC90sof 0.12 μg/mL or less, 0.12 μg/mL or less and 1 μg/mL, respectively. The most active agents againstPseudomonas aeruginosawere amikacin, cefepime, meropenem and piperacillin-tazobactam with MIC90sof 32 μg/mL, 32 μg/mL, 8 μg/mL and 64 μg/mL, respectively. The most active agents againstStenotrophomonas maltophiliawere tigecycline and trimethoprimsulfamethoxazole and levofloxacin with MIC90sof 8 μg/mL, 8 μg/mL and 8 μg/mL, respectively. The most active agents againstAcinetobacter baumanniiwere amikacin, fluoroquinolones (eg, levofloxacin), meropenem, and tigecycline with MIC90sof 2 μg/mL or less, 1 μg/mL, 4 μg/mL and 2 μg/mL, respectively. CONCLUSIONS: The most active agents versus Gram-positive cocci from Canadian hospitals were vancomycin, linezolid, daptomycin, tigecycline, dalbavancin and telavancin. The most active agents versus Gram-negative bacilli from Canadian hospitals were amikacin, cefepime, ertapenem (notP aeruginosa), meropenem, piperacillintazobactam and tigecycline (notP aeruginosa). Colistin (polymyxin E) was very active againstP aeruginosaandA baumannii.

Vancomycin-resistant enterococci with vanA gene in treated municipal wastewater and their association with human hospital strains

2017 ◽  
Vol 609 ◽  
pp. 633-643 ◽  
Author(s):  
Veronika Oravcova ◽  
Matus Mihalcin ◽  
Jana Zakova ◽  
Lucie Pospisilova ◽  
Martina Masarikova ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Vana Gene ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Treated Municipal Wastewater

scholarly journals Antimicrobial resistance of Enterococcus faecium and Enterococcus faecalis, isolated from blood culture of patients with hematological malignancies during different study periods

2021 ◽  
Vol 16 (1) ◽  
pp. 54-63
Author(s):  
A. V. Fedorova ◽  
G. A. Klyasova ◽  
I. N. Frolova ◽  
S. A. Khrulnova ◽  
A. V. Vetokhina ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Blood Culture ◽  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
High Susceptibility ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Level

Objective: to determine antimicrobial resistance of Enterococcus faecium and Enterococcus faecalis isolated from blood culture of hematological patients during different study periods.Materials and methods. Antimicrobial susceptibility of Enterococcus spp., collected as part of the multicenter study was tested by the broth microdilution method (USA Clinical and Laboratory Standards Institute (CLSI), 2018), to daptomycin by Etest (bioMeriéux, France). High-level gentamicin resistance (HLGR) and high-level streptomycin resistance (HLSR) was performed by the agar dilution method (CLSI (Oxoid, UK), 2018).Results. The susceptibility of 366 E. faecium (157 in 2002-2009 and 209 in 2010-2017) and 86 E. faecalis (44 in 20022009 and 42 in 2010-2017) was studied. In the second study period (2010-2017) the rise of vancomycin-resistant E. faecium (VREF) increased from 8.3 % to 23.4 % (p = 0.0001), and two linezolid-resistant (LREF) were identified. All VREF and LREF remained susceptible to daptomycin and tigecycline. The rate of susceptible to tetracycline E. faecium remained the same (73.9 and 74.6 %), and an increase in susceptibility to chloramphenicol (74.5 and 82.3 %) was observed. Susceptibility of E. faecium to tetracycline was detected with almost the same rate and in a part of isolates, the increase of susceptibility to chloramphenicol was registered during the analyzed periods. The rise of E. faecium susceptible to HLGR and HLSR has increased significantly in 2010-2017 compared to 2002-2009. Erythromycin, levofloxacin, ampicillin and penicillin had the least activity against E. faecium (less than 5 %).All E. faecalis were susceptible to tigecycline, linezolid, and teicoplanin. Only one of E. faecalis had intermediate resistance to vancomycin. High susceptibility to ampicillin in E. faecalis remained unchanged (97.7 and 97.6 %, respectively). In the second period of the study the rise of susceptible E. faecalis decreased significantly to penicillin (from 97.7 % to 76.2 %), to levofloxacin (from 59.1 % to 31 %), to HLSR (from 52.3 % до 31 %), and to HLGR (from 47.7 % to 26.2 %), remained unchanged to chloramphenicol (52.3 % and 50 %) and was minimal to erythromycin and tetracycline.Conclusion. The study demonstrated higher rates of antibiotic resistance among E. faecium, which consisted of an increase in VREF and the appearance of linezolid-resistant strains. High susceptibility to ampicillin remained in E. faecalis, but there was an increase in resistance to penicillin and aminoglycosides.

scholarly journals Mechanism of VanB Phenotype in Vancomycin-Resistant Enterococci carrying vanA gene

2006 ◽  
Vol 26 (6) ◽  
pp. 412-417 ◽  
Author(s):  
Il Joong Park ◽  
Wee Gyo Lee ◽  
Hyukmin Lee ◽  
Dongeun Yong ◽  
Kyungwon Lee ◽  
...  
Keyword(s):  
Vana Gene ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant
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