ABSTRACT
PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Erythromycin/therapeutic use , Penicillin Resistance , Respiratory Tract Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Argentina/epidemiology , Brazil/epidemiology , Community-Acquired Infections/drug therapy , Community-Acquired Infections/epidemiology , Community-Acquired Infections/microbiology , Drug Resistance, Multiple , Erythromycin/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Haemophilus influenzae/drug effects , Haemophilus influenzae/isolation & purification , Humans , Mexico/epidemiology , Microbial Sensitivity Tests , Moraxella catarrhalis/drug effects , Moraxella catarrhalis/isolation & purification , Population Surveillance , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/isolation & purificationABSTRACT
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.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporin Resistance , Cephalosporins/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Bacterial Infections/microbiology , Humans , Intensive Care Units , Microbial Sensitivity Tests , CefpiromeABSTRACT
Objetivo. Avaliar a atividade in vitro da cefalosporina de quarta geraçao, cefpiroma em comparaçao com ceftazidima, ceftriaxona, cefotaxima e imipenem em um estudo multicêntrico envolvendo nove hospitais de seis cidades em quatro estados. Material e Métodos. Foram estudadas 804 amostras clínicas isoladas em pacientes internados em unidades de terapia intensiva ou unidades de oncohematologia. As amostras foram coletadas no período de junho a novembro de 1995, isto é, antes da cefpiroma estar disponível comercialmente no Brasil, e testadas através do método de microdiluiçao em placas conforme descrito pelo National Committee for Clinical Laboratory Standards (NCCLS). Todas as amostras resistentes à cefpiroma foram retestadas utilizando-se o E-test. Resultados. Contra as amostras de enterobactérias (n=344), a cefpiroma apresentou atividade de 2 a 32 vezes superior àquela apresentada pelas cefalosporinas de terceira geraçao (CTGs) e semelhnate àquela apresentada pelo imipenem. As porcentagens de enterobactérias sensíveis foram: 88 por cento para a cefpiroma, 69 por cento para as CTGs e 96 por cento para o imipenem. O espectro de açao da cefpiroma foi maior ou igual ao do imipenem contras as espécies Citrobacter freundii, E. aerogenes, Morganella morganii e Serratia marcescens. Contra Acinetobacter sp. (n=77), a cefpiroma foi ligeiramente mais ativa que a ceftazidima, porém as porcentagens de resistência foram muito altas para esses compostos (84 por cento e 88 por cento respectivamente). As atividades da cefpiroma, ceftazidima e imipenem foram semelhantes contra Pseudomonas aeruginosa (n=128), com MIC50/porcentagem de sensibilidade de 8/59 por cento, 8/62 por cento e 4/62 por cento respectivamente. Contra bactérias aeróbias gram-positivas, a cefpiroma foi de 4 a 16 vezes mais ativa que as CTGs. Contra S. epidermidis e outras espécies de estafilococos coagulase-negativos a cefpiroma foi ligeiramente superior ao imipenem, porém, contra as outras espécies de bactérias gram-positivas avaliadas, o imipenem apresentou atividade um pouco superior. Conclusao: Os resultados desse estudo sugerem que, no Brasil, a cefpiroma apresenta espectro de açao superior ao das CTGs contra bactérias gram-negativas (Enterobacteriaceae e nao fermentadares) e gram-positivas e semelhante ao do imipenem contra algumas espécies de enterobactérias e contra P. aeruginosa.
Subject(s)
Cephalosporins/pharmacology , Cephalosporin Resistance , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Lactams/pharmacology , Bacterial Infections/microbiology , Microbial Sensitivity Tests , Intensive Care UnitsABSTRACT
The in vitro activity of cefepime was compared to that of ceftazidime, ceftriaxone, and cefotaxime in a multicenter study involving 10 clinical microbiology laboratories and clinical isolates from 18 Brazilian hospitals from 7 cities (4 states). A total of 982 isolates consecutively collected between December 1995 and March 1996 were susceptibility tested by using Etest and following the NCCLS procedures for agar diffusion tests. The cefepime spectrum was broader than that of the other broad-spectrum cephalosporins against both Gram-negative rods and Gram-positive cocci. Cefepime was particularly more active against Enterobacter sp. (MIC90, 2 micrograms/ml), Serratia sp. (MIC90, 2 micrograms/ml) and oxacillin-susceptible Staphylococcus aureus (MIC90, 3 micrograms/ml). Against Pseudomonas aeruginosa, cefepime (MIC90, 16 micrograms/ml) was slightly more active than ceftazidime (MIC90, 32 micrograms/ml) and 8- to 16-fold more active than ceftriaxone of cefotaxime (MIC90, > 256 micrograms/ml). Our results show that nosocomial bacteria, especially Gram-negative rods, have a high rate of cephalosporin resistance in Brazil. However, part of these resistant bacteria remains susceptible to cefepime. The Etest was shown to be an excellent method for multicenter studies of the in vitro evaluation of new antimicrobial agents.
