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- ItemSomente MetadadadosActivity of ceftobiprole against methicillin-resistant Staphylococcus aureus strains with reduced susceptibility to daptomycin, linezolid or vancomycin, and strains with defined SCCmec types(Elsevier B.V., 2014-04-01) Farrell, David J.; Flamm, Robert K.; Sader, Helio S. [UNIFESP]; Jones, Ronald N.; JMI Labs; Univ Toronto; Universidade Federal de São Paulo (UNIFESP); Tufts UnivCeftobiprole is a broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative pathogens including Pseudomonas aeruginosa. the aim of this study was to evaluate the activity of ceftobiprole against MRSA isolates with decreased susceptibility to daptomycin, linezolid or vancomycin as well as isolates from staphylococcal chromosome cassette mec (SCCmec) types I, II, III and IV. Overall, ceftobiprole demonstrated high potency against the 216 isolates tested, with MIC50 and MIC90 values (minimum inhibitory concentrations required to inhibit 50% and 90% of the isolates, respectively) of 1 mg/L and 2 mg/L (97.2% susceptible). the MIC90 for ceftobiprole was 2 mg/L against the linezolid-non-susceptible, daptomycin-non-susceptible and vancomycin-intermediate (VISA and hVISA) subsets and was 1 mg/L against the vancomycin-resistant (VRSA) strains. the MIC50/90 values for ceftobiprole were 214, 112, 212 and 111 mg/L against SCCmec types I, II, III and IV, respectively. SCCmec type I strains had the highest MICs, with six strains exhibiting a ceftobiprole MIC of 4 mg/L and 15 strains at 2 mg/L. Ceftobiprole demonstrated potent activity against MRSA, including subsets of isolates with reduced susceptibility to daptomycin, linezolid and vancomycin. the activity of ceftobiprole against these resistant phenotypes indicates that it may have clinical utility in the treatment of infections caused by multidrug-resistant S. aureus and across strains from prevalent SCCmec types. (C) 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
- ItemSomente MetadadadosAntimicrobial Resistance among Gram-Positive Bacteria Isolated in Latin American Hospitals(Esift Srl, 2009-12-01) Sader, Helio Silva [UNIFESP]; Moet, G. J.; Jones, R. N.; JMI Labs; Universidade Federal de São Paulo (UNIFESP); Tufts UnivAntimicrobial resistance patterns of the most frequently isolated Gram-positive bacteria in selected Latin American hospitals were evaluated under the auspices of the SENTRY Antimicrobial Surveillance Program. The strains were consecutively collected (one per patient) between January 2003 and December 2008 and tested by reference broth microdilution methods at the monitoring central laboratory (JMI Laboratories, North Liberty, Iowa, USA). A total of 12,324 Gram-positive cocci were analyzed. The organisms were isolated from bloodstream (53.2%) and skin and skin structure infections (16.4%). Resistance to oxacillin (MRSA) was observed in 40.0% of Staphylococcus aureus, varying from 32.7% in Brazil to 49.7% in Chile. Resistance to erythromycin (90.1%), clindamycin (84.4%), and levofloxacin (86.8%) was very high in MRSA. Vancomycin, linezolid and daptomycin were all very active against S. aureus strains tested (>99.9-100.0% susceptible), but daptomycin (MIC(50/90), 0.25/0.5 mu g/ml) was four- to eight-fold more potent than three comparators. Vancomycin resistance increased from 5.0% in 2003 to 15.5% in 2008 among enterococci (VRE); the most significant increase occurred among isolates from Brazilian medical centers (from 6.9 to 31.1%). Daptomycin was the most active antimicrobial tested against enterococci in general (MIC(50/90) 1/2 mu g/ml; 100.0% susceptible), followed by linezolid (MIC(50/90), 1/2 mu g/ml; 99.9% susceptible), teicoplanin (MIC(50) and MIC(90) of <= 2 mu g/ml; 91.3% susceptible), vancomycin (MIC(50/90), 1/8 mu g/ml; 89.6% susceptible). In summary, daptomycin and linezolid showed excellent in vitro activity against Gram-positive organisms (12,324) collected in Latin American hospitals, including MRSA, VRE and other multidrug-resistant organisms.
- ItemSomente MetadadadosAntimicrobial susceptibility of Gram-positive bacterial isolates from the Asia-Pacific region and an in vitro evaluation of the bactericidal activity of daptomycin, vancomycin, and teicoplanin: a SENTRY Program Report (2003-2004)(Elsevier B.V., 2007-08-01) Biedenbacha, Douglas J.; Bellb, Jan M.; Sadera, Helio S.; Fritsche, Thomas R.; Jones, Ronald N.; Turnidge, John D.; JMI Labs; Womens & Childrens Hosp; Universidade Federal de São Paulo (UNIFESP); Tufts UnivMedical centres in eight countries in the Asia-Pacific region provided 2391 isolates for the SENTRY Antimicrobial Surveillance Program during 2003-2004 to determine their susceptibility to several antimicrobial classes, including daptomycin. Daptomycin, vancomycin and teicoplanin minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined for 120 isolates of Staphylococcus aureus, which included wild-type (WT) methicillin-resistant S. aureus (MRSA) and strains with decreased susceptibility to vancomycin (hetero-vancomycin-intermediate S. aureus (hVISA)). Oxacillin-resistant staphylococcal isolates were much less susceptible to the other tested agents compared with oxacillin-susceptible strains. Vancomycin resistance was higher among Enterococcus faecium (10.3%) than Enterococcus faecalis (0.4%), and macrolide resistance was high both for beta-haemolytic (17.7%) and viridans group (48.7%) streptococci. Daptomycin (MIC for 90% of the organisms (MIC90) = 0.5-1 mg/L) was two-fold more potent than vancomycin, with > 99% susceptibility when tested against staphylococci. All tested isolates of E. faecalis (MIC90 = 2 mg/L) and P-haemolytic streptococci (MIC90 = 0.5 mg/L) were susceptible to daptomycin. Daptomycin MIC and MBC values were slightly higher for the hVISA isolates compared with WT-MRSA, with MBC/MIC ratios of only 1-2 for both groups. the MBC/MlC ratio for vancomycin was often greater when tested against these strains, particularly hVISA. in contrast, teicoplanin MBC/MIC ratios were significantly higher, with many of the strains showing values consistent with tolerance (>= 32). Daptomycin was demonstrated to have excellent in vitro activity when tested against Gram-positive isolates collected from Asia-Pacific countries, including hVISA strains. (c) 2007 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
- ItemSomente MetadadadosAntimicrobial susceptibility of Gram-positive cocci isolated from skin and skin-structure infections in European medical centres(Elsevier B.V., 2010-07-01) Sader, Helio S. [UNIFESP]; Farrell, David J.; Jones, Ronald N.; JMI Labs; Universidade Federal de São Paulo (UNIFESP); Tufts UnivSkin and skin-structure infections (SSSIs) usually involve Gram-positive organisms. Prompt initiation of appropriate antimicrobial treatment is essential for achieving a favourable outcome in severe cases. Empirical antibacterial therapy should be based on several considerations, including patient risk factors, expected pathogens and local/regional susceptibility profiles, among others. in the present study, we evaluated the antimicrobial susceptibility patterns of Gram-positive bacteria isolated from patients with SSSIs hospitalised in European medical centres. A total of 3573 bacterial isolates were collected from 33 medical centres located in 13 European countries as well as Israel over a 6-year period (2003-2008) and were tested for susceptibility to daptomycin and other comparator agents by reference broth microdilution methods in a central laboratory. the most frequently isolated organisms were Staphylococcus aureus (71.1%), beta-haemolytic streptococci (10.5%) and enterococci (9.3%). Overall, rates of meticillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) were 22.5% and 5.1%, respectively, but with great intercountry variation. the overall MRSA rate varied slightly during the study period, but with no overall tendency toward increase or decrease, whilst the overall VRE rate consistently increased from 1.5% in 2003 to 11.0% in 2008. Daptomycin and linezolid were the most active agents tested overall. All isolates monitored were considered susceptible to daptomycin, and only one isolate (Enterococcus faecium) was categorised as non-susceptible to linezolid. in conclusion, the results of this contemporary surveillance study indicate that daptomycin and linezolid retain sustained in vitro activity against Gram-positive cocci isolated from patients hospitalised with SSSI in numerous European medical centres. (C) 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
- ItemSomente MetadadadosAre we doing enough to prevent methicillin-resistant Staphylococcus aureus outbreaks?(Lippincott Williams & Wilkins, 2011-07-01) Carvalho, Werther Brunow de; Machado Fonseca, Marcelo Cunio [UNIFESP]; Jurfest Rivero Ceccon, Maria Esther; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
- ItemSomente MetadadadosCaracterização fenotípica e genotípica de isolados clínicos de Staphylococcus aureus resistentes à oxacilina (MRSA) provenientes de atendimento em unidade de emergência hospitalar de alta complexidade(Universidade Federal de São Paulo (UNIFESP), 2021) Miguel, Bianca Trassi [UNIFESP]; Kiffer, Carlos Roberto Veiga [UNIFESP]; Universidade Federal de São PauloObjectives: Methicillin-resistant Staphylococcus aureus (MRSA) are common colonizers of the skin and mucous membranes in healthy individuals. When infectious, MRSA can be classified as HA-MRSA, if hospital or healthcare associated, or as CA-MRSA, when no hospital or healthcare associated origin is identified. Understanding CA-MRSA epidemiology may benefit from simpler and easier methods to predict its prevalence. This study aimed to analyze the phenotypic and genotypic profiles of emergency unit MRSA isolates. Material and methods: The selection of samples was carried out through the analysis of a database. For inclusion in the project, the samples should have been identified as Staphylococcus aureus and had an antibiogram including at least Clindamycin and Sulfamethoxazole + Trimethoprim. Subsequently, the identification of strains was confirmed by the MALDI-TOF technique and subjected to susceptibility tests by the Kirby-Bauer technique for the antimicrobials Clindamycin, Sulfamethoxazole + Trimethoprim and Ceftaroline. The presence of the lukF gene was analyzed using the protocol by Johnsson et al. (2004) and mecA gene and SCCmec types using the protocol by Zhang et al. (2009). Subsequently, comparative analyses were performed between the results obtained by disk-diffusion and automated procedure (BD Phoenix ™) for reliability purposes. Also, analyses correlating SCCmec types categorized as potential HA- or CA-MRSA were compared with susceptibility profiles for Clindamycin and Sulfamethoxazole + Trimethoprim, in order to determine which phenotypic profile could best predict for specific SCCmec types. Results: When performing susceptibility tests to antimicrobials in 122 isolates, 39.5% were susceptible to Clindamycin, 57.4% to Sulfametoxazole + Trimethoprim and 88.5% to Ceftaroline. 6,55%presented lukF virulence gene (PVL). 107 isolates showed only one SCCmec type, while eleven strains were not typable and four strains presented more than one SCCmec types. Non typable samples or samples with more than one SCCmec types were sent for whole genome sequencing (partnership with Harvard University). Ceftaroline was excluded from sensitivity statistical analysis because both categories, CA- and HAMRSA, were equally susceptible to it. Of 107 MRSA isolates, 72% had SCCmecxviii I, II or III and 28% SCCmec IV. The comparative statistical analysis between susceptibility profiles by disk-diffusion and automated method showed a result with low agreement for both antimicrobials. The sensisitivity analyses for phenotypic and genotypic comparisons showed that isolates susceptible to Clindamycin presented 88.5% PPV, 91.4%NPV, 76.7% sensitivity, 96.1% specificity, and 0.8% likelihood ratio associated to SCCmec types IV or V. Isolates susceptible to Sulfamethoxazole + Trimethoprim showed lower PPV (26.2%), NPV (69%), sensitivity (56.7%), and specifici
- ItemSomente MetadadadosDetection of methicillin resistance in Staphylococcus aureus isolated from pediatric patients: Is the cefoxitin disk diffusion test accurate enough?(Contexto, 2007-08-01) Mimica, M. J.; Berezin, Eitan Naaman [UNIFESP]; Carvalho, R. L. B.; Mimica, I. M.; Mimica, L. M. J.; Safadi, Marco Aurelio Palazzi [UNIFESP]; Schneider, E.; Caiaffa-Filho, H. H.; Universidade Federal de São Paulo (UNIFESP); Santa Casa Univ Hosp; Universidade de São Paulo (USP)We evaluated the performance of several methods for the detection of methicillin resistance in Staphylococcus aureus using 101 clinical S. aureus isolates from pediatric patients in a tertiary hospital in Brazil; 50 isolates were mecA-positive and 51 were mecA-negative. The Etest and oxacillin agar screening plates were 100% sensitive and specific for mecA presence. Oxacillin and cefoxitin disks gave sensitivities of 96 and 92%, respectively, and 98% specificity. Alterations of CLSI cefoxitin breakpoints increased sensitivity to 98%, without decreasing specificity. Our results highlight the importance of a continuing evaluation of the recommended microbiological methods by different laboratories and in different settings. If necessary, laboratories should use a second test before reporting a strain as susceptible, especially when testing strains isolated from invasive or serious infections. With the new (2007) CLSI breakpoints, the cefoxitin-disk test appears to be a good option for the detection of methicillin resistance in S. aureus.
- ItemAcesso aberto (Open Access)Efficacy of a program of prevention and control for methicillin-resistant Staphylococcus aureus infections in an intensive-care unit(Brazilian Society of Infectious Diseases, 2007-02-01) Moreira, Marina [UNIFESP]; Freitas, Marise Reis de [UNIFESP]; Martins, Sinaida Teixeira [UNIFESP]; Castelo Filho, Adauto [UNIFESP]; Medeiros, Eduardo Alexandrino Servolo de [UNIFESP]; Taubaté University; Federal University of Rio Grande do Norte; Universidade Federal de São Paulo (UNIFESP)Methicillin-resistant Staphylococcus aureus (MRSA) is endemic in most Brazilian Hospitals, and there are few studies which show the efficacy of control measures in such situations. This study evaluated intensive care unit (ICU) patients, in two years divided in control, intervention and post-intervention group. Intervention measures: hands-on educational programs for healthcare workers; early identification of MRSA infected or colonized patients, labeled with a bed-identification tag for contact isolation; nasal carriers, patients, and healthcare professionals treated with topical mupirocin for five days. The hospital infection rates in the control period were compared to the ones in the post-intervention period. Hospital infection rates were found by means of the NNISS methodology The incidence coefficients of MRSA hospital infection (monthly average of 1,000 pts/day) in the control, intervention and post-intervention groups were respectively: 10.2, 5.1 and 2.5/1,000 pts/day (p<0.001) and MRSA-originated bloodstream infections were 3.6, 0.9 and 1.8/1,000 central venous catheter/day (p=0.281). Nasal colonization in both intervention and post-intervention periods was of 30.9% and 22.1% among the hospitalized patients, respectively 54.4% and 46.1% of whom were already MRSA-positive when admitted to the unit. In the intervention period, most of those MRSA infected patients (76.2%) were nasal carrier. Mortality rates were, respectively 26.6%; 27.3% and 21.0% (p<0.001). Nasal carriers, both patients (93.7%) and healthcare professionals (88.2%), were successfully treated with topical mupirocin. Intervention measures for the prevention and control of MRSA infections in ICUs, have been efficient in the reduction of the bloodstream and MRSA-originated hospital infections incidence, and reduced the overall mortality rate significantly.
- ItemSomente MetadadadosEvaluation of PPI-0903M (T91825), a novel cephalosporin: bactericidal activity, effects of modifying in vitro testing parameters and optimization of disc diffusion tests(Oxford Univ Press, 2005-12-01) Jones, R. N.; Fritsche, T. R.; Ge, Y. G.; Kaniga, K.; Sader, Helio S. [UNIFESP]; JMI Labs Inc; Tufts Univ; Peninsula Pharmaceut; Universidade Federal de São Paulo (UNIFESP)Objectives: To evaluate bactericidal activity of PPI-0903M and in vitro testing parameters for this compound.Methods: A total of 110 strains were tested to determine MIC and MBC values of PPI-0903M. MIC values were determined by reference broth microdilution whereas MBC was assessed by plating the broth from the MIC well and from those wells above the MIC for each organism onto appropriate drug-free growth media. Seventeen strains were tested by the kill-curve methodology to again evaluate the bactericidal activity of PPI-0903M. Broth microdilution results for 15 strains (in triplicate) were compared with the standard, reference method after modifying several testing parameters. Optimal disc content was assessed by testing seven reference strains with five PPI-0903M disc concentrations (5, 10, 30, 50 and 100 mu g).Results: PPI-0903MMBC/MIC ratios were <= 4 in 90% of strains tested. Kill-curve studies showed > 99.9% killing at concentrations <= 4x MIC within 8 to 24 h against staphylococci and Enterobacteriaceae tested. PPI-0903M MIC results were rarely influenced by the test or medium changes evaluated [high inoculum, low calcium or reduced pH (5.0)]. Human serum had no effect on in vitro antimicrobial activity of PPI-0903M. the 10 mu g disc content would be recommended for optimal correlation of MIC breakpoints of <= 1-4 mg/L.Conclusions: PPI-0903M was generally bactericidal against tested species, and the MIC results were stable across numerous susceptibility test condition changes.
- ItemSomente MetadadadosFirst report of methicillin-resistant Staphylococcus aureus Cordobes/Chilean clone involved in nosocomial infections in Brazil(Cambridge Univ Press, 2012-08-01) Becker, A. P.; Santos, O.; Castrucci, F. M. [UNIFESP]; Dias, C.; Alves D'Azevedo, P.; Univ Fed Ciencias Saude Porto Alegre; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Methicillin-resistant Staphylococcus aureus (MRSA) commonly causes infection in hospitalized patients. Resistance is due to the acquisition of mecA gene located on the chromosomal element SCCmec and to date 12 types have been identified. Specific epidemic clones of MRSA have emerged with enhanced ability to spread within and among hospitals and to cross national boundaries. We studied 30 isolates from patients with MRSA infections at two hospitals in Porto Alegre city from April to December, 2008 and determined their SCCmec type by PCR. Representative strains were typed by PFGE. Eighteen (60%) isolates carried SCCmec type III and had PFGE profiles clonally related to the previously characterized Brazilian epidemic clone, and 11 (36.7%) isolates with pulsotypes closely related to the Cordobes/Chilean clone harboured SCCmec type I. To the best of our knowledge, this is the first report of the appearance of Cordobes/Chilean clone involved in nosocomial infection in Brazil.
- ItemSomente MetadadadosOxazolidinone susceptibility patterns for 2005: International report from the Zyvox (R) Annual Appraisal of Potency and Spectrum study(Elsevier B.V., 2007-03-01) Ross, James E.; Fritsche, Thomas R.; Sader, Helio S. [UNIFESP]; Jones, Ronald N.; JMI Labs; Universidade Federal de São Paulo (UNIFESP); Tufts UnivThe international (non-USA) ZAAPS Program has accumulated 4 years of linezolid resistance surveillance results tracking infections caused by organisms with evolving resistance profiles. the major organism groups monitored were: Staphylococcus aureus and coagulase-negative staphylococci (including methicillin [oxacill in] -resistant strains), enterococci (including vancomycin-resistant [VRE] strains), Streptococcus pneumoniae (including multidrug-resistant [MDR] strains), viridans group streptococci and P-haemolytic streptococci (4209 isolates overall). No linezolid-resistant strains were detected from the 16 monitored nations participating in 2005, consistent with previously reported 2002-2004 results. Linezolid remains highly active against Gram-positive strains including MRSA (MIC90, 2mg/L). With MDR in Gram-positive organisms increasing in prevalence, continued surveillance of linezolid appears to be prudent practice as linezolid becomes more widely prescribed for these difficult-to-treat infections. (c) 2007 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
- ItemSomente MetadadadosUpdate of the in vitro activity of daptomycin tested against 6710 Gram-positive cocci isolated in North America (2006)(Elsevier B.V., 2008-06-01) Castanheira, Mariana; Jones, Ronald N.; Sader, Helio S. [UNIFESP]; JMI Labs; Tufts Univ; Universidade Federal de São Paulo (UNIFESP)Gram-positive bacterial strains (6710) consecutively collected during 2006 in hospitals located in the United States and Canada were tested by reference broth microdilution methods against daptomycin and comparison agents. Only 1 Staphylococcus aureus strain (0.01%) had nonsusceptible daptomycin MIC value as specified by published break points. S. aureus daptomycin MIC distributions from 2006 as compared with those of previous years did not show MIC creep. Resistance to other compounds, such as vancomycin, oxacillin and penicillin, did not adversely influence daptomycin activity. Daptomycin remains highly active against clinical Gram-positive isolates collected in North America. (C) 2008 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosZyvox (R) Annual Appraisal of Potency and Spectrum Program results for 2006: an activity and spectrum analysis of linezolid using clinical isolates from 16 countries(Elsevier B.V., 2007-10-01) Jones, Ronald N.; Fritsche, Thomas R.; Sader, Helio S. [UNIFESP]; Ross, James E.; JMI Labs; Tufts Univ; Universidade Federal de São Paulo (UNIFESP)The Zyvox (R) Annual Appraisal of Potency and Spectrum Program has completed its fifth year of monitoring for emerging resistance to linezolid and other Gram-positive active agents on the continents of Europe, Asia, Australia, and Latin America. in 2006, 4216 Gram-positive isolates from 16 nations were submitted for analysis from 6 organism groups including Staphylococcus aureus (54.0%), coagulase-negative staphylococci (CoNS) (14.6%), enterococci (10.0%), Streptococcus pneumoniae (9.4%), viridans group streptococci (5.0%), and beta-hemolytic streptococci (7.0%). Linezolid retained potent activity against S. aureus MIC50 and MIC90, 2 mu g/mL; 39.8% methicillin resistant) and CoNS (MIC50 and MIC90, I mu g/mL; 74.3% methicillin resistant). Despite endemicity of vancomycin-resistant enterococci (up to 30.0%) in several nations, linezolid inhibited >99% of strains at <= 2 mu g/mL (modal MIC, 1 mu g/mL). Among streptococci, all linezolid MIC values were <= 2 mu g/mL. Rare instances of linezolid-resistance were detected in enterococci (2 isolates, China and Germany) and CoNS (3 isolates, Italy and Brazil); 2 CoNS and 1 Enterococcusfiaecium had documented G2576T mutations. Overall, linezolid remained active against 99.88% of tested strains from this global collection. (C) 2007 Elsevier Inc. All rights reserved.