Navegando por Palavras-chave "Antimicrobial susceptibility"

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    Atividade antimicrobiana in vitro da cefpiroma em comparação com outros beta-lactâmicos de amplo espectro contra 804 amostras clínicas de nove hospitais brasileiros
    (Associação Médica Brasileira, 1998-12-01) Sader, Helio Silva [UNIFESP]; Mendes, Caio Márcio Figueredo; Montelli, Augusto; Sampaio, Jorge; Segura, Adilia J A; Kesselring, Gustavo L F [UNIFESP]; Costa, Libera; Ribeiro, José E F [UNIFESP]; Mamizuka, Elza; Mimiça, Igor; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); Universidade Estadual Paulista (UNESP); Laboratório Lâmina; Hospital de Base de Brasília; Universidade Federal do Paraná; Santa Casa de Misericórdia de Belo Horizonte; Santa Casa de Misericórdia de São Paulo
    OBJECTIVE: To evaluate the in vitro activity of the fourth-generation cephalosporin cefpirome in comparison to that of ceftazidime, ceftriaxone, cefotaxime and imipenem in a multicenter study involving nine hospitals from six cities (four States). MATERIAL AND METHOD: A total of 804 isolates from patients hospitalized in either intensive care units or Oncology/Hematology units was evaluated. The isolates were collected between June and November of 1995, i.e. before cefpirome became commercially available in Brazil, and susceptibility tested by broth microdilution following the NCCLS procedures. All isolates resistant to cefpirome were retested by E-test. RESULTS: Against Enterobacteriaceae (n=344), cefpirome demonstrated an activity 2 to 32-fold higher than that of the third-generation cephalosporins (TGCs) and similar to that of imipenem. The percentages of Enterobacteriaceae susceptible were: 88%, 69% and 96% for cefpirome, TGCs and imipenem, respectively. The cefpirome spectrum was greater or equal than that of imipenem against Citrobacter freundii, Enterobacter aerogenes, Morganella morganii and Serratia marcescens. Against Acinetobacter sp. (n=77), cefpirome was slightly more active than ceftazidime; however, the percentages of isolates resistant to these compounds were high (84% and 88%, respectively). The activities of cefpirome, ceftazidime and imipenem were very similar against P. aeruginosa isolates (n=128), with MIC50(mg/ml)/percent susceptible of 8/59%, 8/62% and 4/62% respectively. Against aerobic gram-positive bacteria, the cefpirome activity was 4 to 16-fold higher than that of TGCs but 2 to 8-fold lower than that of imipenem. CONCLUSION: The results suggest that, in Brazil, cefpirome has a spectrum of activity which is higher than that of the TGCs against aerobic gram-negative (Enterobacteriaceae and non-Enterobacteriaceae) and gram-positive bacteria and similar to that of imipenem against some Enterobacteriaceae species and P. aeruginosa.
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    In vitro activity of tigecycline, a new glycylcycline, tested against 1,326 clinical bacterial strains isolated from Latin America
    (Brazilian Society of Infectious Diseases, 2005-10-01) Gales, Ana Cristina [UNIFESP]; Jones, Ronald N.; Andrade, Soraya Sgambatti [UNIFESP]; Pereira, Andrea dos Santos [UNIFESP]; Sader, Helio Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Department of Medicine; The JMI Laboratories
    The in vitro activity of tigecycline (former GAR-936), a new semisynthetic tetracycline, was evaluated in comparison with tetracycline and other antimicrobial agents. MATERIAL AND METHODS: A total of 1,326 contemporary clinical isolates collected from the Latin American region were collected in 2000-2002 period and tested with microdilution broth according to the CLSI guidelines. The bacterial pathogens evaluated included Staphylococcus aureus (505), Streptococcus pneumoniae (269), coagulase-negative staphylococci (CoNS; 227), Haemophilus influenzae (129), Enterococcus spp. (80), Moraxella catarrhalis (54), beta-haemolytic streptococci (28), viridans group streptococci (26), and Neisseria meningitidis (8) RESULTS:Tigecycline demonstrated excellent activity against all Gram-positive cocci, with 90% of penicillin-resistant S. pneumoniae strains being inhibited at 0.12 µg/mL, while the same isolates had an MIC90 of > 16 µg/mL for tetracycline. All Enterococcus spp. were inhibited at 0.25 µg/mL of tigecycline. Tigecycline (MIC50, 0.25 µg/mL) was eight-fold more potent than minocycline (MIC50, 2 µg/mL) against oxacillin-resistant S. aureus (ORSA); all ORSA were inhibited at < 2 µg/mL of tigecycline. Tigecycline demonstrated excellent activity (MIC50, 0.5 µg/mL) against CoNS with reduced susceptibility to teicoplanin (MIC, 16 µg/mL). Tigecycline also showed high potency against respiratory pathogens such as M. catarrhalis (MIC50, 0.12 µg/mL) and H. influenzae (MIC50, 0.5 µg/mL). No tigecycline resistant isolates were detected when the proposed susceptible breakpoints (< 4 µg/mL) was applied. CONCLUSIONS: This results indicate that tigecycline has potent in vitro activity against clinically important pathogenic bacteria, including Gram-positive isolates resistant to both tetracycline and minocycline.