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 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 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.

scholarly journals Genetic diversity of vancomycinresistant Enterococcus faecium isolated from blood culture in patients with hematological malignancies

2021 ◽  
Vol 23 (3) ◽  
pp. 305-313
Author(s):  
Svetlana A. Khrulnova ◽  
Galina A. Klyasova ◽  
A.V. Fedorova ◽  
I.N. Frolova ◽  
B.V. Biderman
Keyword(s):  
Genetic Diversity ◽  
High Risk ◽  
Blood Culture ◽  
Enterococcus Faecium ◽  
Hematological Malignancies ◽  
Clonal Complex ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Polymerase Chain ◽  
Sequence Types

Objective. To study the genetic diversity of vancomycin-resistant Enterococcus faecium (VR-E. faecium) isolated from the blood culture in patients with hematological malignancies by multilocus sequence typing (MLST). Materials and Methods. VR-E. faecium isolated from the blood culture in hematological patients in 6 hospitals of 4 Russian cities (2003–2019) were evaluated. Susceptibility to vancomycin was tested by the broth microdilution method (CLSI, 2018). Vancomycin-resistance genes (vanA, vanB) were identified by polymerase chain reaction. Genotyping of VR-E. faecium was performed by MLST. Results. A total of 83 VR-E. faecium were examined. The vanA genes were detected in 71.1% (n = 59) VR-E. faecium, vanB genes – in 28.9% (n = 24). A total of 22 sequence types (STs) belonging to epidemic clonal complex CC17 were detected. The dominant sequence types were ST17 (19.3%), ST78 (18.1%), ST80 (16.9%), and comprised 54.3% VR-E. faecium. Other sequence types included 1 to 4 strains. VR-E. faecium carrying vanA, in comparison with VR-E. faecium vanB, significantly more often belonged to ST78 (23.7% vs. 4.2%, p = 0.0559, respectively) and ST80 (23.7% versus 0%, p = 0.0079, respectively) and less frequently to ST17 (6,8% versus 50%, р < 0.0001). Circulation of 9 STs including «high-risk» clones ST17 and ST78 was detected during two study periods (2003–2011 and 2012–2019). Conclusions. This study showed a genetic diversity of VR-E. faecium that was represented by 22 STs. All VR-E. faecium belonged to epidemic clonal complex CC17 and comprised «high-risk» clones ST17, ST78 and less common STs.

Antimicrobial Resistance in Campylobacter jejuni from Broilers and Broiler House Environments in Norway

2007 ◽  
Vol 70 (3) ◽  
pp. 736-738 ◽  
Author(s):  
M. NORSTRÖM ◽  
G. JOHNSEN ◽  
M. HOFSHAGEN ◽  
H. THARALDSEN ◽  
H. KRUSE
Keyword(s):  
Antimicrobial Resistance ◽  
Campylobacter Jejuni ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Monitoring Program ◽  
Outdoor Environment ◽  
Susceptibility Data ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Broiler House

Antimicrobial susceptibility in Campylobacter jejuni collected from the environment outside four broiler houses (n = 63) and from the environment inside these broiler houses (including broiler droppings) (n = 36) from May to September 2004 was studied and compared with isolates from Norwegian broilers analyzed within the frame of the Norwegian monitoring program of antimicrobial resistance in feed, food, and animals (NORM-VET) in 2004 (n = 75). The MICs of oxytetracycline, ampicillin, erythromycin, gentamicin, enrofloxacin, and nalidixic acid were obtained by the broth microdilution method VetMIC. The present study, which to our knowledge is the first Norwegian study on the occurrence of antimicrobial resistance in Campylobacter spp. from the environment of broiler houses, revealed a very low occurrence of antimicrobial resistance in C. jejuni from the broilers and broiler house environments studied. All isolates originating from the four broiler houses studied were susceptible to all the antimicrobial agents tested, except for one isolate from the outdoor environment (courtyard soil), which was resistant to oxytetracycline (MIC, 8 mg/liter). For the isolates from broilers (NORM-VET), low prevalences of resistance to oxytetracycline (1.3%) and ampicillin (4%) were observed. No quinolone resistance was observed. The results for the broiler isolates are in agreement with the earlier findings of a very low prevalence of resistance in Campylobacter from broilers in Norway, which reflects the low usage of antimicrobials in Norwegian broiler production. Furthermore, the present data are in accordance with antimicrobial susceptibility data for C. jejuni from domestically acquired human cases.

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 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 Antimicrobial Susceptibility of Lactobacillus delbrueckii subsp. lactis from Milk Products and Other Habitats

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3145
Author(s):  
Noam Shani ◽  
Simone Oberhaensli ◽  
Hélène Berthoud ◽  
Remo S. Schmidt ◽  
Hans-Peter Bachmann
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Resistance Genes ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Minimal Inhibitory Concentrations ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Positive Results ◽  
Lactobacillus Delbrueckii Subsp

As components of many cheese starter cultures, strains of Lactobacillus delbrueckii subsp. lactis (LDL) must be tested for their antimicrobial susceptibility to avoid the potential horizontal transfer of antibiotic resistance (ABR) determinants in the human body or in the environment. To this end, a phenotypic test, as well as a screening for antibiotic resistance genes (ARGs) in genome sequences, is commonly performed. Historically, microbiological cutoffs (MCs), which are used to classify strains as either ‘sensitive’ or ‘resistant’ based on the minimal inhibitory concentrations (MICs) of a range of clinically-relevant antibiotics, have been defined for the whole group of the obligate homofermentative lactobacilli, which includes LDL among many other species. This often leads to inaccuracies in the appreciation of the ABR status of tested LDL strains and to false positive results. To define more accurate MCs for LDL, we analyzed the MIC profiles of strains originating from various habitats by using the broth microdilution method. These strains’ genomes were sequenced and used to complement our analysis involving a search for ARGs, as well as to assess the phylogenetic proximity between strains. Of LDL strains, 52.1% displayed MICs that were higher than the defined MCs for kanamycin, 9.9% for chloramphenicol, and 5.6% for tetracycline, but no ARG was conclusively detected. On the other hand, all strains displayed MICs below the defined MCs for ampicillin, gentamycin, erythromycin, and clindamycin. Considering our results, we propose the adaptation of the MCs for six of the tested clinically-relevant antibiotics to improve the accuracy of phenotypic antibiotic testing.

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