[Detection of vancomycin-resistant Enterococcus faecium: 2 years' experience in a high complexity hospital ]. / Detección de Enterococcus faecium resistente a vancomicina: experiencia de dos años en un hospital de alta complejidad.

The presence of vancomycin-resistant enterococci (VRE) in our hospital prompted us to apply an appropriate method for assessing its rectal carriage. A screening method with bile-esculin azide agar plus different concentrations of vancomycin was used. The antimicrobial susceptibility study of enterococci isolated from clinical samples was also emphasized. The present study includes the surveillance and detection of VRE in our hospital during two years. A total of 260 samples corresponding to 138 patients were studied, 158 of them resulting positive. All EVR were Van A Enterococcus faecium, with MICs of vancomycin > or = 256 micrograms/ml. The analysis of susceptibility patterns shows variations with chloramphenicol, tetracycline and high level gentamicin concentrations. This method was easily applied because materials could be available in any clinical microbiology laboratory, and in our hands it has demonstrated to be useful for epidemiological surveillance for EVR.

[Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]. / Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino.

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19%) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38% were isolated by the anaerobic standard (65% were Propionibacterium spp and 29% coagulase negative staphylococci), 31.2% by the FAN aerobic (33.3% difphteroids and 28.9% Bacillus spp), 11.8% by the pediatric, 9% by FAN pediatric, 8.33% by aerobic standard and 1.4% by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.

[Production of inoculates for leguminous plants. Production of cellular suspensions of Rhizobium (Lotus group)]. / Producción de inoculantes para leguminosas. Obtención de suspensiones celulares de Rhizobium del grupo Lotus.

The influence of culture medium composition and operative conditions on the cellular growth of Rhizobium sp (group Lotus) strain is studied. As much as 1 x 10(9) cell/ml were obtained in 16 hours using sucrose in the medium as carbon source. The best growth rate was obtained (mu = O,22 h-1) when the experiments were performed at 400 r.p.m. and one volume of air/volume of medium x minute (OAR = 793,0 ml of oxygen/1 h).

Detección de Enterococcus faecium resistente a vancomicina: experiencia de dos años en un hospital de alta complejidad / [Detection of vancomycin-resistant Enterococcus faecium: 2 years’ experience in a high complexity hospital ]

The presence of vancomycin-resistant enterococci (VRE) in our hospital prompted us to apply an appropriate method for assessing its rectal carriage. A screening method with bile-esculin azide agar plus different concentrations of vancomycin was used. The antimicrobial susceptibility study of enterococci isolated from clinical samples was also emphasized. The present study includes the surveillance and detection of VRE in our hospital during two years. A total of 260 samples corresponding to 138 patients were studied, 158 of them resulting positive. All EVR were Van A Enterococcus faecium, with MICs of vancomycin > or = 256 micrograms/ml. The analysis of susceptibility patterns shows variations with chloramphenicol, tetracycline and high level gentamicin concentrations. This method was easily applied because materials could be available in any clinical microbiology laboratory, and in our hands it has demonstrated to be useful for epidemiological surveillance for EVR.

Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino / [Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19

) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38

were isolated by the anaerobic standard (65

were Propionibacterium spp and 29

by the FAN aerobic (33.3

difphteroids and 28.9

by the pediatric, 9

by aerobic standard and 1.4

by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.