Navegando por Palavras-chave "Cephalosporins"
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- ItemAcesso aberto (Open Access)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 PauloOBJECTIVE: 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.
- ItemAcesso aberto (Open Access)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.
- ItemAcesso aberto (Open Access)Molecular structure and antibacterialactivity of degradation products from cephalexin solutions submitted to thermal and photolytic stress(Willey, 2022-11-21) da Silva, Emerson Rodrigo [UNIFESP]; Valêncio, André [UNIFESP]; Machado, Marcelo Ferreira Marcondes [UNIFESP]; Miranda, Antonio [UNIFESP]; http://lattes.cnpq.br/7800589206457326; http://lattes.cnpq.br/0596334947896054; http://lattes.cnpq.br/9703373400186586; http://lattes.cnpq.br/1357848049935882; Lourenço, Cecília; Souza, Louise E. A.Cephalexin is a beta-lactam antibiotic of the first generation of cephalosporins which is very effective against various bacterial infections. In this work, we investigate the structure and antibacterial activity of cephalexin solutions submitted to forced degradation under heat stress and photolytic irradiation. A combination of analytical techniques gathering LC/ESI-MS and NMR spectroscopy allowed us to identify different chemical species amongst the byproducts, revealing that photolysis via UV light leads to significant amounts of oxidized species that conserve the dihydrothiazine ring adjacent to the beta-lactam ring. In contrast, thermodegradation induces the rupture of the bioactive moiety possibly with the production of cephalosporinic acid and deaminated species, which are inactive to bacteria. Microbiological analyses using E. coli as a model organism indicated that the antimicrobial capacity of samples submitted to thermolysis is suppressed while solutions submitted to irradiation with UVA light preserve their bactericidal power. Atomic force microscopy showed that cells incubated with photodegraded cephalexin are much longer than those incubated with the undegraded antibiotic, indicating that byproducts from photolysis inhibit septum formation and likely affect the action of penicillin-binding protein 3 in the divisome of E. coli cells.
- ItemSomente MetadadadosRisk factors for enterococcal bacteremia in allogeneic hematopoietic stem cell transplant recipients(Wiley-Blackwell, 2010-12-01) Mikulska, Malgorzata; Del Bono, V.; Prinapori, R.; Boni, L.; Raiola, A. M.; Gualandi, F.; Van Lint, Maria Teresa; Dominietto, A.; Lamparelli, T.; Cappellano, Paola [UNIFESP]; Bacigalupo, Andrea; Viscoli, Claudio; San Martino Univ Hosp; Ist Toscano AOU Tumori Careggi; Universidade Federal de São Paulo (UNIFESP)P>Bacteremia is a well known cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients and enterococci are among the most frequently isolated pathogens. the aim of this study was to identify risk factors for enterococcal bacteremia during the first 30 days after allogeneic HSCT. A retrospective case-control study was performed; for each case, 3 controls were randomly selected among 306 patients transplanted during the study period (January 1, 2004 to December 31, 2007). Odds ratios (OR) with 95% confidence intervals (CI) were calculated for variables influencing the risk for bacteremia. Overall, 33 patients developed enterococcal bacteremia, within a median of 9 days after HSCT (range, 2-24). the cumulative incidence was 10.8%. Multivariate analysis identified the following variables as risk factors for enterococcal bacteremia: donor and transplant type (greater risk for mismatched related or cord blood) (OR=8.98, 95% CI, 1.65-48.99 and OR=7.52, 95% CI, 1.56-36.31, respectively, P=0.047); severe (grades 3-4) mucositis (OR=9.04, 95% CI, 1.97-41.52, P=0.018); pharyngeal enterococcal colonization (OR=4.48, 95% CI, 1.11-18.03, P=0.035); and previous empirical therapy with cephalosporins (OR=4.16, 95% CI, 0.93-18.66 for 1-7 days of therapy, and OR=7.31, 95% CI, 1.78-30.12 for 8-23 days, P=0.018). Higher Karnofsky score (>= 50) and previous empirical therapy with glycopeptides were associated with a decreased risk (OR=0.25, 95% CI, 0.06-0.97, P=0.045 and OR=0.11, 95% CI, 0.02-0.59, P=0.010, respectively). the crude mortality at 7 and 30 days was 12% (4/33) and 24% (8/33), respectively. Enterococcal bacteremia is frequent after allogeneic HSCT. the factors associated with this infection are type of transplant, pharyngeal colonization, severe mucositis, and use of cephalosporins. Good general conditions and the use of vancomycin were associated with lower risk of enterococcal bacteremia.