Navegando por Palavras-chave "Carbapenens"

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    Avaliação comparativa de distintos métodos fenotípicos para a detecção de cepas produtoras de carbapenemases
    (Universidade Federal de São Paulo (UNIFESP), 2016-08-22) Moura, Jhonatha Rodrigo Cordeiro de [UNIFESP]; Gales, Ana Cristina [UNIFESP]; http://lattes.cnpq.br/8402272715765172; http://lattes.cnpq.br/2346858488495749; Universidade Federal de São Paulo (UNIFESP)
    During the last decade, it has been observed the rapid development of antimicrobial resistance among clinical isolates of Enterobacteriaceae, Pseudomonas spp., and Acinetobacter spp. worldwide. The production of ?-lactamases is the most important mechanism of resistance in Gram-negative bacilli, being the carbapenemases the most versatile mechanisms of carbapenem resistance. These enzymes have broad spectrum of activity, making difficult the selection of adequate antimicrobial therapy. Furthermore, genes encoding ?-lactamases are highly transmissible. Objective: This study aimed to evaluate the performance of five phenotypic methods for detection of carbapenemase-producing Gram-negative bacilli. Methods: Strains previously characterized were pulled out from the LEMC/ALERTA bank of microorganisms. The confirmation of carbapenemase production was performed by ertapenem hydrolysis using MALDI-TOF MS. The phenotypic tests evaluated were: Hodge modified test, ANVISA Technical Note 01/2013, Carba NP and its modification, CarbAcineto NP, Blue-Carba, CarbapenemBac, and CarbapenemBac Metallo. Results: Although the specificity rates of the ANVISA Technical Note and MHT were 100%, the Technical Note (97.3%) showed higher sensitivity rate than that of the MHT (88.5%) for carbapenemase detection. The Carba NP, Blue-Carba and CarbapenemBac tests showed high sensitivity and specificity rates (100%) when colonies subcultured on Mueller-Hinton agar were tested. The sensitivity and specificity rates of Carba NP (98.6 and 100%), BlueCarba (97.1 and 91%) and CarbapenemBac (96.5 and 100%) were slightly lower when bacterial colonies were obtained from blood agar. On the other hand, the sensitivity rates of Carba NP (71.1%) and Blue-carba (68.9%) were unacceptable when colonies obtained from MacConkey agar were evaluated. However, the sensitivity of CarbapenemBac (97.3% sensitivity) was less affected by the MacConkey agar. Conclusions: We conclude that 1. The colorimetric methods showed excellent sensitivity and specificity for carbapenemases detection when bacterial colonies were subcultured on Mueller-Hinton agar or blood agar; 2. Bacteria colonies subcultured on MacConkey agar must not be utilized for colorimetric tests, except for CarbapenemBac, which showed a good sensitivity and specificity rates for detection of carbapenemases independently of the culture medium used to subculture the bacterial isolate.
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    Avaliação da atividade in vitro dos novos antimicrobianos da classe das fluoroquinolonas, cefalosporinas e carbapenens contra 569 amostras clínicas de bactérias gram-negativas
    (Associação Médica Brasileira, 1997-06-01) Gales, Ana Cristina [UNIFESP]; Pignatari, Antonio Carlos Campos [UNIFESP]; Jones, R.n. [UNIFESP]; Baretta, M. [UNIFESP]; Sader, Helio Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    OBJECTIVE. Evaluation of the in vitro activity of new fluoroquinolones, cephalosporins and carbapenems against gram-negative bacteria. MATERIAL AND METHOD. A total of 569 clinical isolates were obtained from inpatients at São Paulo Hospital - UNIFESP/EPM in June and July of 1992. The species distribution was as follows: Enterobacter sp. (62), Escherichia coli (308), Klebsiella pneumoniae (27), Klebsiella sp. (9), Proteus mirabilis (23), Pseudomonas aeruginosa (88), Pseudomonas sp. (4), Serratia sp. (30) and other gram-negatives (7). Susceptibility tests were performed by broth microdilution. The antimicrobials agents tested were: ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, DU 6859-a, ceftazidime, cefepime, FK 037, imipenem, meropenem and biapenem. RESULTS. DU 6859-a showed the highest antimicrobial activity among the fluoroquinolones. It was two- to four-fold more active than ciprofloxacin against some species. The potency and antimicrobial spectrum were similar between the fourth-generation cephalosporins against Enterobacteriaceae, except for Enterobacter sp. strains which were more susceptible to cefepime than they were to cefetazidime or FK 037. When testing Pseudomonas aeruginosa, ceftazidime was slightly more active than the other cephalosporins. Against Enterobacteriaceae and Pseudomonas aeruginosa strains, meropenem was more active than imipenem or biapenem. In addition, the percentage of strains, susceptible to meropenem was higher than the percentage susceptible to the other cerbapenems against these species. CONCLUSION. The new antimicrobial agents demonstrated in vitro activity higher than that of agents commercially avaliable. However, more studies are necessary to further evaluate the in vivo activity and the clinical benefit of these compounds.
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    Comparação das atividades antimicrobianas de meropenem e imipenem/cilastatina: o laboratório necessita testar rotineiramente os dois antimicrobianos?
    (Sociedade Brasileira de Patologia ClínicaSociedade Brasileira de PatologiaSociedade Brasileira de Citopatologia, 2002-01-01) Gales, Ana Cristina [UNIFESP]; Mendes, Rodrigo Elisandro [UNIFESP]; Rodrigues, José [UNIFESP]; Sader, Helio Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Meropenem and imipenem are the most active and potent ß-lactams against gram-negative bacteria and the only carbapenems commercially available in Brazil, USA, and Europe. Meropenem has higher in vitro activity against gram-negative bacteria, while imipenem has slightly higher in vitro activity against gram-positive. The objectives of this study are to compare the in vitro activities of these carbapenems and to evaluate the necessity of susceptibility testing both compounds at the routine of the microbiology laboratory. The broth microdilution results of 2,144 gram-negative bacilli were analyzed. Against Enterobacteriaceae meropenem was at least eight-fold more potent than imipenem. Against Pseudomonas aeruginosa meropenem (MIC50, 1mug/ml) was also more potent than imipenem (MIC50, 2mug/ml), and against Acinetobacter baumannii both carbapenems presented similar in vitro activities (MIC50, 1mug/ml for both). Only 2.7% of the isolates presented discrepant category results between the carbapenems; i.e. susceptible to one and resistant to the other. Forty-six isolates (2.14%) were susceptible to meropenem and resistant to imipenem; while only 12 isolates (0.55%) were susceptible to imipenem and resistant to meropenem. The vast majority of discordant results (91.4%) occur among non-fermentative bacilli (NF-BGN). Five discordant results were detected among 1,350 Enterobacteriaceae evaluated (0.37%); while 53 discrepant results were detected among 794 NF-BGN (6.64%). Isolates showing susceptibility to meropenem and resistance to imipenem account for 80% of the discrepant results. The results of this study indicate that the microbiology laboratory may susceptibility test only one of the carbapenems for Enterobacteriaceae and use the same category result for the other one. It is important that the results for both carbapenems are sent to the physicians in order for them to be able to choose the most appropriated for the case. On the other hand, for NF-BGN the laboratory should susceptibility test both carbapenems.