Argentinean collaborative multicenter study on the in vitro comparative activity of piperacillin-tazobactam against selected bacterial isolates recovered from hospitalized patients.

The in vitro activity of piperacillin-tazobactam and several antibacterial drugs commonly used in Argentinean hospitals for the treatment of severe infections was determined against selected but consecutively isolated strains from clinical specimens recovered from hospitalized patients at 17 different hospitals from 9 Argentinean cities from different geographic areas during the period November 2001-March 2002. Out of 418 Enterobacteriaceae included in the Study 84% were susceptible to piperacillin-tazobactam. ESBLs putative producers were isolated at an extremely high rate since among those isolates obtained from patients with hospital acquired infections 56% of Klebsiella pneumoniae, 32% of Proteus mirabilis and 25% Escherichia coli were phenotypically considered as ESBLs producers Notably P.mirabilis is not considered by for screening for ESBL producers. ESBLs producers were 100% susceptible to imipenem and 70% were susceptible to piperacillin-tazobactam whereas more than 50% were resistant to levofloxacin. The isolates considered as amp C beta lactamase putative producers showed 99% susceptibility to carbapenems while 26.7% were resistant to piperacillin-tazobactam and 38.4% to levofloxacin. Noteworthy only 4% of the Enterobacteriaceae isolates were resistant to amikacin. Piperacillin-tazobactam was the most active agent against Pseudomonas aeruginosa isolates (MIC(90): 128 microg/ml; 78% susceptibility) but showed poor activity against Acinetobacter spp (MIC(90):>256 microg/ml; 21.7% susceptibility). Only 41.7% Acinetobacter spp isolates were susceptible to ampicillin-sulbactam. Piperacillin-tazobactam inhibited 100% of Haemophilus influenzae isolates (MIC(90) < 0.25 microg/ml) but only 16.6% of them were ampicillin resistant. The activity of piperacillin-tazobactam against oxacillin susceptible Staphylococcus aureus or coagulase negative staphylococci was excellent (MIC(90) 2 microg/ml; 100% susceptibility). Out of 150 enterococci 12 isolates (8%) were identified as E.faecium and only three isolates (2%), 2 E.faecium and 1 E.faecalis were vancomycin resistant. All the enterococci isolates were susceptible to linezolid. Piperacillin-tazobactam showed excellent activity (MIC(90) 2 microg/ml; 92% susceptibility). Regarding pneumococci all the isolates showed MICs of 16 microg/ml for piperacillin-tazobactam. Among 34 viridans group streptococci only 67% were penicillin susceptible and 85.2% ceftriaxone susceptible whereas piperacillin-tazobactam was very active (MIC(90) 4 microg/ml).Piperacillin-tazobactam is therefore a very interesting antibacterial drug to be used, preferably in combination (IE: amikacin-vancomycin) for the empiric treatment of severe infections occurring in hospitalized patients in Argentina. Caution must be taken for infections due to ESBL producers considering that the inoculum effect MICs can affect MIC values.

[Clinical and epidemiological study of adult patients with positive blood cultures]. / Estudio clinico y epidemiológico de pacientes adultos con hemocultivo positivo.

A cohort evaluation of the microbiology, epidemiology and outcome of adult patients with positive blood cultures was performed on 336 patients, from July 1997 to March 2000. Data for mortality were obtained from 328 of these patients. The six most common pathogens were Staphylococcus aureus: 81 (23.5%), coagulase negative staphylococci: 50 (14.5%), Escherichia coli: 48 (14.0%), Streptococcus pneumoniae: 30 (8.7%), enterococci: 19 (5.5%) and Pseudomonas aeruginosa: 19 (5.5%). In 169 episodes infections were hospital-acquired and community-acquired in the remaining 159. Main infection foci included the respiratory and urinary tracts. Infection associated mortality was 33.2%; 29.6% of patients received inappropriate empiric antibiotic treatment. Univariate analysis showed that an age of 70 or more years, a systemic inflammatory response syndrome (SIRS) score higher than 2, a polimicrobial episode, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment influenced outcome. By multivariate analysis the variables that influenced death by infectious cause were age of 70 or more years, a SIRS score higher than 2, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment. SIRS score was useful to predict the positivity of the blood culture. No relation between outcome and presence of underlying disease, isolation of Gram negative microorganism and nosocomial vs. community acquired episode was observed (univariate analysis). In order to improve outcome in bacteremic patients, after performing cultures of blood and other relevant clinical foci, prompt and appropriate antibiotic treatment remains critical. Microbiologic, clinical and epidemiological information results crucial for the management of this critically ill population.

Estudio clinico y epidemiologico de pacientes adultos con hemocultivo positivO / Clinical and epidemiological study of adult patients with positive blood cultures

A cohort evaluation of the microbiology, epidemiology and outcome of adult patients with positive blood cultures was performed on 336 patients, from July 1997 to March 2000. Data for mortality were obtained from 328 of these patients. The six most common pathogens were Staphylococcus aureus: 81 (23.5 percent), coagulase negative staphylococci: 50 (14.5 percent), Escherichia coli: 48 (14.0 percent), Streptococcus pneumoniae: 30 (8.7 percent), enterococci: 19 (5.5 percent) and Pseudomonas aeruginosa: 19 (5.5 percent). In 169 episodes infections were hospital-acquired and community-acquired in the remaining 159. Main infection foci included the respiratory and urinary tracts. Infection associated mortality was 33.2 percent; 29.6 percent of patients received inappropriate empiric antibiotic treatment. Univariate analysis showed that an age of 70 or more years, a systemic inflammatory response syndrome (SIRS) score higher than 2, a polimicrobial episode, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment influenced outcome. By multivariate analysis the variables that influenced death by infectious cause were age of 70 or more years, a SIRS score higher than 2, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment. SIRS score was useful to predict the positivity of the blood culture. No relation between outcome and presence of underlying disease, isolation of Gram negative microorganism and nosocomial vs. community acquired episode was observed (univariate analysis). In order to improve outcome in bacteremic patients, after performing cultures of blood and other relevant clinical foci, prompt and appropriate antibiotic treatment remains critical. Microbiologic, clinical and epidemiological information results crucial for the management of this critically ill population. AD - Hospital Municipal de San Isidro, Provincia de Buenos Aires, Capitan Juan de San Martin 1531, 1609 Boulogne, Pcia. Buenos Aires.

Estudio clinico y epidemiológico de pacientes adultos con hemocultivo positivo. / [Clinical and epidemiological study of adult patients with positive blood cultures]

A cohort evaluation of the microbiology, epidemiology and outcome of adult patients with positive blood cultures was performed on 336 patients, from July 1997 to March 2000. Data for mortality were obtained from 328 of these patients. The six most common pathogens were Staphylococcus aureus: 81 (23.5

), coagulase negative staphylococci: 50 (14.5

), Escherichia coli: 48 (14.0

), Streptococcus pneumoniae: 30 (8.7

), enterococci: 19 (5.5

) and Pseudomonas aeruginosa: 19 (5.5

). In 169 episodes infections were hospital-acquired and community-acquired in the remaining 159. Main infection foci included the respiratory and urinary tracts. Infection associated mortality was 33.2

; 29.6

of patients received inappropriate empiric antibiotic treatment. Univariate analysis showed that an age of 70 or more years, a systemic inflammatory response syndrome (SIRS) score higher than 2, a polimicrobial episode, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment influenced outcome. By multivariate analysis the variables that influenced death by infectious cause were age of 70 or more years, a SIRS score higher than 2, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment. SIRS score was useful to predict the positivity of the blood culture. No relation between outcome and presence of underlying disease, isolation of Gram negative microorganism and nosocomial vs. community acquired episode was observed (univariate analysis). In order to improve outcome in bacteremic patients, after performing cultures of blood and other relevant clinical foci, prompt and appropriate antibiotic treatment remains critical. Microbiologic, clinical and epidemiological information results crucial for the management of this critically ill population.

Estudio clinico y epidemiologico de pacientes adultos con hemocultivo positivO / Clinical and epidemiological study of adult patients with positive blood cultures

A cohort evaluation of the microbiology, epidemiology and outcome of adult patients with positive blood cultures was performed on 336 patients, from July 1997 to March 2000. Data for mortality were obtained from 328 of these patients. The six most common pathogens were Staphylococcus aureus: 81 (23.5 percent), coagulase negative staphylococci: 50 (14.5 percent), Escherichia coli: 48 (14.0 percent), Streptococcus pneumoniae: 30 (8.7 percent), enterococci: 19 (5.5 percent) and Pseudomonas aeruginosa: 19 (5.5 percent). In 169 episodes infections were hospital-acquired and community-acquired in the remaining 159. Main infection foci included the respiratory and urinary tracts. Infection associated mortality was 33.2 percent; 29.6 percent of patients received inappropriate empiric antibiotic treatment. Univariate analysis showed that an age of 70 or more years, a systemic inflammatory response syndrome (SIRS) score higher than 2, a polimicrobial episode, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment influenced outcome. By multivariate analysis the variables that influenced death by infectious cause were age of 70 or more years, a SIRS score higher than 2, certain foci (abdominal, respiratory or unknown), and an inappropriate empiric antibiotic treatment. SIRS score was useful to predict the positivity of the blood culture. No relation between outcome and presence of underlying disease, isolation of Gram negative microorganism and nosocomial vs. community acquired episode was observed (univariate analysis). In order to improve outcome in bacteremic patients, after performing cultures of blood and other relevant clinical foci, prompt and appropriate antibiotic treatment remains critical. Microbiologic, clinical and epidemiological information results crucial for the management of this critically ill population. AD - Hospital Municipal de San Isidro, Provincia de Buenos Aires, Capitan Juan de San Martin 1531, 1609 Boulogne, Pcia. Buenos Aires. (AU)

Atributos epidemiologicos de pacientes internados con bacteriemias / Epidemiologic attributes of inpatients with bacteriuria

Se estudiaron historias clinicas de 59 pacientes con bacteriemias registrados en la Seccion de Bacteriologia del Laboratorio Central del Hospital Municipal de San Isidro, pcia. de Buenos Aires. Se determino su distribucion por edad, sexo y riesgo. Se dieron a conocer los germenes detectados por orden de frecuencia y sensibilidad antibiotica predominante Gram (+) y Gram (-)