Molecular Typing and Antimicrobial Susceptibility of Vancomycin-ResistantEnterococcus faeciumin Brazil

2002 ◽  
Vol 23 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Rosangela F. Cereda ◽  
Ana C. Gales ◽  
Suzane Silbert ◽  
Ronald N. Jones ◽  
Helio S. Sader
Keyword(s):  
Resistance Genes ◽  
Molecular Typing ◽  
Medical Center ◽  
Sao Paulo ◽  
Vancomycin Resistance ◽  
São Paulo ◽  
Microdilution Method ◽  
Medical Centers ◽  
Broth Microdilution Method ◽  
Vancomycin Resistant

AbstractObjectives:To characterize vancomycin-resistant enterococci (VRE) isolates and to evaluate the mode of dissemination of this pathogen in Brazil.Design:We collected 22 vancomycin-resistantEnterococcus faeciumisolates from 6 medical centers in Sao Paulo, Brazil, and 1 isolate from a medical center in Curitiba, Brazil.Participants:All Brazilian hospitals that had identified vancomycin-resistantE. faeciumup to the beginning of this study (late 1999) contributed isolates to the study.Methods:The isolates were susceptibility tested using the broth microdilution method and the E-test. The presence of vancomycin resistance genes (vanA,vanB,vanC1,vanC2-3, andvanD) was evaluated by polymerase chain reaction; molecular typing was performed by pulsed-field gel electrophoresis (PFGE).Results:ThevanA gene was demonstrated in all vancomycin-resistantE. faecium, except for 1 isolate. None of the vancomycin resistance genes cited above was detected in the isolate from Curitiba, which was the first vancomycin-resistantE. faeciumdescribed in Brazil. All isolates were resistant to ampicillin and teicoplanin. The main clone remains susceptible to doxycycline and chloramphenicol, but intermediate to quinupristin-dalfopristin. PFGE analysis demonstrated 7 major PFGE patterns. A unique PFGE pattern with 4 subtypes was detected in 17 isolates from 4 different hospitals.Conclusion:The results of our study indicate the occurrence of intra- and interhospital dissemination of VRE in Sao Paulo, Brazil.

scholarly journals Molecular typing and occurrence of beta-lactam resistance genes ofShigella sonneistrains isolated from 1983 to 2014 in the São Paulo state of Brazil

2017 ◽  
Vol 61 (12) ◽  
pp. 547-553
Author(s):  
Amanda Ap. Seribelli ◽  
Miliane R. Frazão ◽  
Marta I. Cazentini Medeiros ◽  
Eliana G. Stehling ◽  
Juliana P. Falcão
Keyword(s):  
Resistance Genes ◽  
Molecular Typing ◽  
Sao Paulo ◽  
São Paulo ◽  
Beta Lactam ◽  
Paulo State ◽  
São Paulo State

scholarly journals Evaluation of Vancomycin and Daptomycin Potency Trends (MIC Creep) against Methicillin-Resistant Staphylococcus aureus Isolates Collected in Nine U.S. Medical Centers from 2002 to 2006

2009 ◽  
Vol 53 (10) ◽  
pp. 4127-4132 ◽  
Author(s):  
Helio S. Sader ◽  
Paul D. Fey ◽  
Douglas N. Fish ◽  
Ajit P. Limaye ◽  
George Pankey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Center ◽  
Geometric Mean ◽  
Yearly Variation ◽  
Microdilution Method ◽  
Medical Centers ◽  
Broth Microdilution Method ◽  
Vancomycin Mics ◽  
Type Population ◽  
Mrsa Strains

ABSTRACT Vancomycin MIC creep has been reported by some institutions but not confirmed in large surveillance studies. We evaluated the possible occurrence of MIC creep when testing vancomycin and daptomycin against methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) by using precise incremental reference MIC methods. Nine hospitals (one in each U.S. census region) randomly selected bloodstream MRSA strains (target, 40/year) from 2002 to 2006. MICs were determined by the reference broth microdilution method using incremental dilutions (eight for each log2 dilution step). Isolates for which vancomycin MICs were >1 μg/ml were typed by pulsed-field gel electrophoresis (PFGE). The vancomycin MIC mode was either 0.625 μg/ml (for eight hospitals) or 0.813 μg/ml (for one hospital), and vancomycin MIC results for 72.9% of strains were between 0.563 and 0.688 μg/ml. No yearly variation in the central tendency of vancomycin MICs for the wild-type population in any medical center was observed; however, when data were analyzed by the geometric mean statistic, vancomycin MIC increases (at three sites) and declines (at three sites) were observed. The daptomycin MIC mode varied from 0.156 μg/ml (2003 to 2005) to 0.219 μg/ml (2002 and 2006), and MIC results for 83.5% (80.3 to 89.2% in each of the centers) of isolates fell between these values. Among PFGE-typed strains, 43 of 55 (78%; from seven hospitals) showed a pattern consistent with that of the USA100 clone, which was represented by all strains from two hospitals and 64 to 88% of strains from five other medical centers; only one strain (2%) was USA300. In conclusion, the perception of MIC creep may vary according to the methods used to analyze the data. Geometric mean MIC data revealed a possible, very-low-level MIC creep at three of nine sites over the 5-year period, which was not evident using modal MICs or the data from all nine hospitals (+0.02 μg/ml). The occurrence of isolates for which the vancomycin MIC was >1 μg/ml was very unusual, with no increased trend, but these organisms were usually clonal (USA100).

scholarly journals Detection and typing of vancomycin-resistance genes of enterococci from clinical and nosocomial surveillance specimens by multiplex PCR

2001 ◽  
Vol 126 (3) ◽  
pp. 357-363 ◽  
Author(s):  
J. J. LU ◽  
C. L. PERNG ◽  
T. S. CHIUEH ◽  
S. Y. LEE ◽  
C. H. CHEN ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Resistance Genes ◽  
Culture Method ◽  
Vancomycin Resistance ◽  
Conventional Culture ◽  
Multiplex Pcr Assay ◽  
Vancomycin Resistant ◽  
Surveillance Specimens ◽  
Conventional Culture Method

Ninety-three clinical isolates of vancomycin-resistant enterococci (VRE) collected from nine hospitals in Taiwan were examined for the presence of vanA, vanB, vanC1, or vanC2/vanC3 genes by a multiplex PCR. Forty-seven of these VRE isolates were vanA positive, 1 contained both vanC1 and vanA, 40 harboured vanB, 2 were vanC1, and 3 were identified to be vanC2/vanC3. Twenty-four vanA isolates were sensitive to teicoplanin and thus did not have a typical VanA phenotype. Five isolates with the VanC phenotype harboured vanB. None of the 40 clinically isolated vancomycin-susceptible E. faecium or E. faecalis and the vancomycin-resistant Leuconostoc and Pediococcus isolates were positive for any of the van genes. While performing nosocomial surveillance, VRE were isolated from 47 of 467 rectal swabs by culture. Compared with the conventional culture method, the sensitivity and specificity of the multiplex PCR for detecting and identifying vancomycin-resistance genes in enterococci directly from culture-positive broth were 97·9% and 100%, respectively. The results suggest that genotypic characterization of vancomycin-resistance is necessary for all clinical VRE isolates and that the multiplex PCR assay can be an alternative method for this purpose.

scholarly journals Prevalence of a Cefazolin Inoculum Effect Associated withblaZGene Types among Methicillin-SusceptibleStaphylococcus aureusIsolates from Four Major Medical Centers in Chicago

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Sheila K. Wang ◽  
Annette Gilchrist ◽  
Anastasia Loukitcheva ◽  
Balbina J. Plotkin ◽  
Ira M. Sigar ◽  
...  
Keyword(s):  
Fold Increase ◽  
Type A ◽  
Content Type ◽  
Microdilution Method ◽  
Medical Centers ◽  
High Inoculum ◽  
Gene Type ◽  
Broth Microdilution Method ◽  
Type C ◽  
Inoculum Effect

ABSTRACTThe efficacy of cefazolin with high-inoculum methicillin-susceptibleStaphylococcus aureus(MSSA) infections remains in question due to therapeutic failure inferred as being due to an inoculum effect (InE). This study investigated the local prevalence of a cefazolin InE (CInE) and its association with staphylococcalblaZgene types among MSSA isolates in the Chicago area. Four medical centers in Chicago, IL, contributed MSSA isolates. Cefazolin MICs (C-MIC) were determined at 24 h by the broth microdilution method using a standard inoculum (SI; 5 × 105CFU/ml) and a high inoculum (HI; 5 × 107CFU/ml). The CInE was defined as (i) a ≥4-fold increase in C-MIC between SI and HI and/or (ii) a pronounced CInE, i.e., a nonsusceptible C-MIC of ≥16 μg/ml at HI. PCR was used to amplify theblaZgene, followed by agarose gel electrophoresis and sequencing to determine the gene type. Approximately 269 MSSA isolates were included. All but one isolate were susceptible to cefazolin at SI, and 97% remained susceptible at HI. A total of 196 isolates (73%) wereblaZpositive, with theblaZtypes led by gene type C (40%). CInE was seen in 45blaZ-positive isolates (23%), with 44 (22%) presenting a ≥4-fold increase in C-MIC (SI to HI) and 5 (3%) a pronounced CInE. Four of the five met both definitions of CInE, two of which expressed the type A gene. The prevalence of a pronounced CInE associated with the type AblaZgene from MSSA isolates in Chicago is low. Our predilection for cefazolin use, even early in the management of hospitalized MSSA infections, is tenable.

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 Arbekacin Activity against Contemporary Clinical Bacteria Isolated from Patients Hospitalized with Pneumonia

2015 ◽  
Vol 59 (6) ◽  
pp. 3263-3270 ◽  
Author(s):  
Helio S. Sader ◽  
Paul R. Rhomberg ◽  
David J. Farrell ◽  
Ronald N. Jones
Keyword(s):  
The United States ◽  
Multidrug Resistant ◽  
Surveillance Program ◽  
Content Type ◽  
Microdilution Method ◽  
Medical Centers ◽  
Broth Microdilution Method ◽  
Mrsa Strains ◽  
Infection Types

ABSTRACTArbekacin is a broad-spectrum aminoglycoside licensed for systemic use in Japan and under clinical development as an inhalation solution in the United States. We evaluated the occurrence of organisms isolated from pneumonias in U.S. hospitalized patients (PHP), including ventilator-associated pneumonia (VAP), and thein vitroactivity of arbekacin. Organism frequency was evaluated from a collection of 2,203 bacterial isolates (339 from VAP) consecutively collected from 25 medical centers in 2012 through the SENTRY Antimicrobial Surveillance Program. Arbekacin activity was tested against 904 isolates from PHP collected in 2012 from 62 U.S. medical centers and 303 multidrug-resistant (MDR) organisms collected worldwide in 2009 and 2010 from various infection types. Susceptibility to arbekacin and comparator agents was evaluated by the reference broth microdilution method. The four most common organisms from PHP wereStaphylococcus aureus,Pseudomonas aeruginosa,Klebsiellaspp., andEnterobacterspp. The highest arbekacin MIC amongS. aureusisolates from PHP (43% methicillin-resistantS. aureus[MRSA]) was 4 μg/ml. AmongP. aeruginosaisolates from PHP, only one had an arbekacin MIC of >16 μg/ml (MIC50and MIC90, 1 and 4 μg/ml), and susceptibility rates for gentamicin, tobramycin, and amikacin were 88.0, 90.0, and 98.0%, respectively. Arbekacin (MIC50, 2 μg/ml) and tobramycin (MIC50, 4 μg/ml) were the most potent aminoglycosides tested againstAcinetobacter baumannii. AgainstEnterobacteriaceaefrom PHP, arbekacin and gentamicin (MIC50and MIC90, 0.25 to 1 and 1 to 8 μg/ml for both compounds) were generally more potent than tobramycin (MIC50and MIC90, 0.25 to 2 and 1 to 32 μg/ml) and amikacin (MIC50and MIC90, 1 to 2 and 2 to 32 μg/ml). Arbekacin also demonstrated potentin vitroactivity against a worldwide collection of well-characterized MDR Gram-negative and MRSA strains.

scholarly journals Molecular typing and antifungal susceptibility of clinical sequential isolates of Cryptococcus neoformans from Sao Paulo State, Brazil

2007 ◽  
Vol 7 (1) ◽  
pp. 152-164 ◽  
Author(s):  
Ana Marisa Fusco Almeida ◽  
Marcelo Teruyuki Matsumoto ◽  
Lilian Cristiane Baeza ◽  
Rosana Bellan De Oliveira e Silva ◽  
Aline Aparecida Pizzirani Kleiner ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Molecular Typing ◽  
Antifungal Susceptibility ◽  
Sao Paulo ◽  
São Paulo ◽  
Paulo State ◽  
São Paulo State

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 Activity of Ceftolozane-Tazobactam Tested against Enterobacteriaceae and Pseudomonas aeruginosa with Various Resistance Patterns Isolated in U.S. Hospitals (2011-2012)

2013 ◽  
Vol 57 (12) ◽  
pp. 6305-6310 ◽  
Author(s):  
David J. Farrell ◽  
Robert K. Flamm ◽  
Helio S. Sader ◽  
Ronald N. Jones
Keyword(s):  
Pseudomonas Aeruginosa ◽  
The United States ◽  
Multidrug Resistant ◽  
High Rate ◽  
Drug Resistant ◽  
Good Activity ◽  
Content Type ◽  
Microdilution Method ◽  
Medical Centers ◽  
Broth Microdilution Method

ABSTRACTCeftolozane/tazobactam, a novel antimicrobial agent with activity againstPseudomonas aeruginosa(including drug-resistant strains) and other common Gram-negative pathogens (including most extended-spectrum-β-lactamase [ESBL]-producingEnterobacteriaceaestrains), and comparator agents were susceptibility tested by a reference broth microdilution method against 7,071Enterobacteriaceaeand 1,971P. aeruginosaisolates. Isolates were collected consecutively from patients in 32 medical centers across the United States during 2011 to 2012. Overall, 15.7% and 8.9% ofP. aeruginosaisolates were classified as multidrug resistant (MDR) and extensively drug resistant (XDR), and 8.4% and 1.2% ofEnterobacteriaceaewere classified as MDR and XDR. No pandrug-resistant (PDR)Enterobacteriaceaeisolates and only one PDRP. aeruginosaisolate were detected. Ceftolozane/tazobactam was the most potent (MIC50/90, 0.5/2 μg/ml) agent tested againstP. aeruginosaand demonstrated good activity against 310 MDR strains (MIC50/90, 2/8 μg/ml) and 175 XDR strains (MIC50/90, 4/16 μg/ml). Ceftolozane/tazobactam exhibited high overall activity (MIC50/90, 0.25/1 μg/ml) againstEnterobacteriaceaeand retained activity (MIC50/90, 4/>32 μg/ml) against many 601 MDR strains but not against the 86 XDR strains (MIC50, >32 μg/ml). Ceftolozane/tazobactam was highly potent (MIC50/90, 0.25/0.5 μg/ml) against 2,691Escherichia coliisolates and retained good activity against most ESBL-phenotypeE. coliisolates (MIC50/90, 0.5/4 μg/ml), but activity was low against ESBL-phenotypeKlebsiella pneumoniaeisolates (MIC50/90, 32/>32 μg/ml), explained by the high rate (39.8%) of meropenem coresistance observed in this species phenotype. In summary, ceftolozane/tazobactam demonstrated high potency and broad-spectrum activity against many contemporaryEnterobacteriaceaeandP. aeruginosaisolates collected in U.S. medical centers. Importantly, ceftolozane/tazobactam retained potency against many MDR and XDR strains.

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