[Quantitative cultures from catheters, using the Brun Buisson technique]. / Cultivos cuantitativos de catéteres por la técnica de Brun Buisson.

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10% CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).

Cultivos cuantitativos de catéteres por la técnica de Brun Buisson / Quantitative cultures from catheters, using the Brun Buisson technique

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10 CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).

Cultivos cuantitativos de catéteres por la técnica de Brun Buisson / Quantitative cultures from catheters, using the Brun Buisson technique

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10 CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).(AU)

Cultivos cuantitativos de catéteres por la técnica de Brun Buisson. / [Quantitative cultures from catheters, using the Brun Buisson technique]

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10

CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).

[Utility of prolonged incubation and terminal subcultures of blood cultures from immunocompromised patients]. / Utilidad de la incubación prolongada y de los subcultivos terminales de hemocultivos de pacientes inmunocomprometidos.

The value of blind terminal subcultures (7 and 30 days) and prolonged incubation (30 days) of blood cultures from immunosuppressed patients was analyzed in the Fundación Favaloro, the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia and the Hospital de Niños Ricardo Gutiérrez. A total of 2707 blood cultures and 369 patients were included (transplantation of solid organs 154, oncohematologic disorders 106 and solid tumors 109). Bact-Alert bottles were incubated at 35 degrees C for 30 days in the Bact-Alert System. Bottles with positive signals were routinely removed, and aliquots of the broth were Gram stained and subcultured aerobically in chocolate agar and Sabouraud agar. A total of 136 bacteremic episodes were obtained. The positivization time of blood cultures was 81.6% at 24 h, 93.3% at 48 h, 94.5% at 72 h and 97.7% within 7 days. Only 3 (2.2%) episodes were positive by blind terminal subcultures and 1 (0.75%) by prolonged incubation (14 days). The median time and range of positivization in hours were 13.8 and 2.2-168, respectively. The microorganisms isolated were coagulase negative staphylococci (n = 24), Klebsiella pneumoniae (n = 22), Staphylococcus aureus (n = 21), Escherichia coli (n = 18), Acinetobacter spp (n = 9), Candida spp (n = 8), Pseudomonas aeruginosa (n = 6), Enterobacter cloacae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterococcus faecalis, Salmonella spp and Capnocytophaga sputigena (n = 2), Enterobacter aerogenes, Enterococcus faecium, Citrobacter diversus, Candida albicans, Klebsiella oxytoca, Chryseomonas luteola, Serratia marcescens, Abiotrophia spp, Campylobacter jejuni, Moraxella catarrhalis, Moraxella urethralis, Neisseria sicca, beta hemolytic group G streptococci, Rhodococcus equi, Micrococcus spp, Cryptococcus neoformans and Streptococcus mitis (n = 1). In our experience, blind terminal subcultures and prolonged incubation of blood cultures from immunosuppressed patients are unnecessary and cost expensive.

Utilidad de la incubación prolongada y de los subcultivos terminales de hemocultivos de pacientes inmunocomprometidos / Utility of prolonged incubation and terminal subcultures of blood cultures from immunocompromised patients

The value of blind terminal subcultures (7 and 30 days) and prolonged incubation (30 days) of blood cultures from immunosuppressed patients was analyzed in the Fundación Favaloro, the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia and the Hospital de Niños Ricardo GutiÚrrez. A total of 2707 blood cultures and 369 patients were included (transplantation of solid organs 154, oncohematologic disorders 106 and solid tumors 109). Bact-Alert bottles were incubated at 35 degrees C for 30 days in the Bact-Alert System. Bottles with positive signals were routinely removed, and aliquots of the broth were Gram stained and subcultured aerobically in chocolate agar and Sabouraud agar. A total of 136 bacteremic episodes were obtained. The positivization time of blood cultures was 81.6 at 24 h, 93.3 at 48 h, 94.5 at 72 h and 97.7 within 7 days. Only 3 (2.2) episodes were positive by blind terminal subcultures and 1 (0.75) by prolonged incubation (14 days). The median time and range of positivization in hours were 13.8 and 2.2-168, respectively. The microorganisms isolated were coagulase negative staphylococci (n = 24), Klebsiella pneumoniae (n = 22), Staphylococcus aureus (n = 21), Escherichia coli (n = 18), Acinetobacter spp (n = 9), Candida spp (n = 8), Pseudomonas aeruginosa (n = 6), Enterobacter cloacae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterococcus faecalis, Salmonella spp and Capnocytophaga sputigena (n = 2), Enterobacter aerogenes, Enterococcus faecium, Citrobacter diversus, Candida albicans, Klebsiella oxytoca, Chryseomonas luteola, Serratia marcescens, Abiotrophia spp, Campylobacter jejuni, Moraxella catarrhalis, Moraxella urethralis, Neisseria sicca, beta hemolytic group G streptococci, Rhodococcus equi, Micrococcus spp, Cryptococcus neoformans and Streptococcus mitis (n = 1). In our experience, blind terminal subcultures and prolonged incubation of blood cultures from immunosuppressed patients are unnecessary and cost expensive.

Utilidad de la incubación prolongada y de los subcultivos terminales de hemocultivos de pacientes inmunocomprometidos / Utility of prolonged incubation and terminal subcultures of blood cultures from immunocompromised patients

The value of blind terminal subcultures (7 and 30 days) and prolonged incubation (30 days) of blood cultures from immunosuppressed patients was analyzed in the Fundación Favaloro, the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia and the Hospital de Niños Ricardo GutiUrrez. A total of 2707 blood cultures and 369 patients were included (transplantation of solid organs 154, oncohematologic disorders 106 and solid tumors 109). Bact-Alert bottles were incubated at 35 degrees C for 30 days in the Bact-Alert System. Bottles with positive signals were routinely removed, and aliquots of the broth were Gram stained and subcultured aerobically in chocolate agar and Sabouraud agar. A total of 136 bacteremic episodes were obtained. The positivization time of blood cultures was 81.6 at 24 h, 93.3 at 48 h, 94.5 at 72 h and 97.7 within 7 days. Only 3 (2.2) episodes were positive by blind terminal subcultures and 1 (0.75) by prolonged incubation (14 days). The median time and range of positivization in hours were 13.8 and 2.2-168, respectively. The microorganisms isolated were coagulase negative staphylococci (n = 24), Klebsiella pneumoniae (n = 22), Staphylococcus aureus (n = 21), Escherichia coli (n = 18), Acinetobacter spp (n = 9), Candida spp (n = 8), Pseudomonas aeruginosa (n = 6), Enterobacter cloacae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterococcus faecalis, Salmonella spp and Capnocytophaga sputigena (n = 2), Enterobacter aerogenes, Enterococcus faecium, Citrobacter diversus, Candida albicans, Klebsiella oxytoca, Chryseomonas luteola, Serratia marcescens, Abiotrophia spp, Campylobacter jejuni, Moraxella catarrhalis, Moraxella urethralis, Neisseria sicca, beta hemolytic group G streptococci, Rhodococcus equi, Micrococcus spp, Cryptococcus neoformans and Streptococcus mitis (n = 1). In our experience, blind terminal subcultures and prolonged incubation of blood cultures from immunosuppressed patients are unnecessary and cost expensive.(AU)

Utilidad de la incubación prolongada y de los subcultivos terminales de hemocultivos de pacientes inmunocomprometidos. / [Utility of prolonged incubation and terminal subcultures of blood cultures from immunocompromised patients]

The value of blind terminal subcultures (7 and 30 days) and prolonged incubation (30 days) of blood cultures from immunosuppressed patients was analyzed in the Fundación Favaloro, the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia and the Hospital de Niños Ricardo Gutiérrez. A total of 2707 blood cultures and 369 patients were included (transplantation of solid organs 154, oncohematologic disorders 106 and solid tumors 109). Bact-Alert bottles were incubated at 35 degrees C for 30 days in the Bact-Alert System. Bottles with positive signals were routinely removed, and aliquots of the broth were Gram stained and subcultured aerobically in chocolate agar and Sabouraud agar. A total of 136 bacteremic episodes were obtained. The positivization time of blood cultures was 81.6

at 24 h, 93.3

at 48 h, 94.5

at 72 h and 97.7

within 7 days. Only 3 (2.2

) episodes were positive by blind terminal subcultures and 1 (0.75

) by prolonged incubation (14 days). The median time and range of positivization in hours were 13.8 and 2.2-168, respectively. The microorganisms isolated were coagulase negative staphylococci (n = 24), Klebsiella pneumoniae (n = 22), Staphylococcus aureus (n = 21), Escherichia coli (n = 18), Acinetobacter spp (n = 9), Candida spp (n = 8), Pseudomonas aeruginosa (n = 6), Enterobacter cloacae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterococcus faecalis, Salmonella spp and Capnocytophaga sputigena (n = 2), Enterobacter aerogenes, Enterococcus faecium, Citrobacter diversus, Candida albicans, Klebsiella oxytoca, Chryseomonas luteola, Serratia marcescens, Abiotrophia spp, Campylobacter jejuni, Moraxella catarrhalis, Moraxella urethralis, Neisseria sicca, beta hemolytic group G streptococci, Rhodococcus equi, Micrococcus spp, Cryptococcus neoformans and Streptococcus mitis (n = 1). In our experience, blind terminal subcultures and prolonged incubation of blood cultures from immunosuppressed patients are unnecessary and cost expensive.

Sistema bact-alert de hemocultivos: evaluación de los subcultivos terminales / Bact-Alert system for hemocultures: evaluation of terminal subcultures

Few laboratory microbiological procedures are as important as the isolation of microorganisms from blood. To evaluate the usefulness of the terminal subcultures, 5669 blood cultures giving negative results after 7 days of incubation in the Bact/Alert System (Organon Teknika) were studied. Bottles were distributed as follows: 1562 adult aerobic bottles, 119 adult anaerobic bottles, 3960 pediatric bottles and 28 FAN bottles. From 5669 blood cultures, 10 subcultures that yielded growth had not been detected by the system. These included 5 adult aerobic bottles and 5 pediatric bottles, 7 of these microorganisms were considered contaminants according to clinical data (2 Micrococcus spp, 1 staphylococci coagulase negative, 1 Burkholderia cepacia, 1 Peptoestreptococcus spp, 1 Corynebacterium spp, 1 Scedosporium spp) while the other 3 were considered true bacteremia (1 Pseudomonas aeruginosa, 1 Proteus mirabilis, 1 Streptococcus sanguis), although no one made any change in treatment on the basis of the previous isolation. Based on these results the routinary utilization of terminal subcultures is not advisable and should be used only for special cases or a second system of blood culture should be added according to clinical or epidemiological data.

Sistema bact-alert de hemocultivos: evaluación de los subcultivos terminales / Bact-Alert system for hemocultures: evaluation of terminal subcultures

Few laboratory microbiological procedures are as important as the isolation of microorganisms from blood. To evaluate the usefulness of the terminal subcultures, 5669 blood cultures giving negative results after 7 days of incubation in the Bact/Alert System (Organon Teknika) were studied. Bottles were distributed as follows: 1562 adult aerobic bottles, 119 adult anaerobic bottles, 3960 pediatric bottles and 28 FAN bottles. From 5669 blood cultures, 10 subcultures that yielded growth had not been detected by the system. These included 5 adult aerobic bottles and 5 pediatric bottles, 7 of these microorganisms were considered contaminants according to clinical data (2 Micrococcus spp, 1 staphylococci coagulase negative, 1 Burkholderia cepacia, 1 Peptoestreptococcus spp, 1 Corynebacterium spp, 1 Scedosporium spp) while the other 3 were considered true bacteremia (1 Pseudomonas aeruginosa, 1 Proteus mirabilis, 1 Streptococcus sanguis), although no one made any change in treatment on the basis of the previous isolation. Based on these results the routinary utilization of terminal subcultures is not advisable and should be used only for special cases or a second system of blood culture should be added according to clinical or epidemiological data.(AU)

[Blood cultures: use of presumptive antiobiograms]. / Hemocultivos: utilidad de los antibiogramas presuntivos.

Mortality associated to bacteremia varies between 20 and 40% depending upon several factors, such as focus of infection, microorganism, host conditions, etc. It has also been documented that mortality may double when the patient does not receive antibiotic treatment to which the microorganism is susceptible. The objective of our work has been to determine the correlation between disk diffusion antibiogram according to NCCLS guidelines, from isolated colonies, and the one performed directly from the blood culture flask. During 1996, in the Institute of Cardiology and Cardiovascular Surgery (ICYCC) in Buenos Aires City, 81 episodes of bacteremia were studied. In every case, an antibiogram was carried out: 1) from the bottle: a- Directly (D), harvesting 20 microliters in Mueller Hinton agar, b- Diluted (d), previous centrifugation and Gram staining to adjust turbidity equivalent to 0.5 Mc Farland; 2) from isolated colonies, according to NCCLS guidelines. There were almost no major errors, except with two strains of Enterobacter cloacae versus cephalotin. The diluted method was not so convenient to read inhibition zones, especially with staphylococci. With gram-positive bacteria, the main problems appeared in the direct method with erythromycin, oxacillin and ciprofloxacin because of minor errors. With gram-negative bacteria, major errors were observed in the direct method, mainly with piperacillin (7%) and to a lesser extent with piperacillin tazobactam (2%). Except for imipenem, trimethoprim sulfamethoxazoie and cefotaxime, all antimicrobial agents presented minor errors with both methodologies. Based upon the high rate of minor errors, we consider it is important to confirm results obtained with the standard technique (NCCLS), considering as presumptive those results from the blood culture bottles (D and d).

Hemocultivos: utilidad de los antibiogramas presuntivos / Blood cultures: use of presumptive antiobiograms

Mortality associated to bacteremia varies between 20 and 40 depending upon several factors, such as focus of infection, microorganism, host conditions, etc. It has also been documented that mortality may double when the patient does not receive antibiotic treatment to which the microorganism is susceptible. The objective of our work has been to determine the correlation between disk diffusion antibiogram according to NCCLS guidelines, from isolated colonies, and the one performed directly from the blood culture flask. During 1996, in the Institute of Cardiology and Cardiovascular Surgery (ICYCC) in Buenos Aires City, 81 episodes of bacteremia were studied. In every case, an antibiogram was carried out: 1) from the bottle: a- Directly (D), harvesting 20 microliters in Mueller Hinton agar, b- Diluted (d), previous centrifugation and Gram staining to adjust turbidity equivalent to 0.5 Mc Farland; 2) from isolated colonies, according to NCCLS guidelines. There were almost no major errors, except with two strains of Enterobacter cloacae versus cephalotin. The diluted method was not so convenient to read inhibition zones, especially with staphylococci. With gram-positive bacteria, the main problems appeared in the direct method with erythromycin, oxacillin and ciprofloxacin because of minor errors. With gram-negative bacteria, major errors were observed in the direct method, mainly with piperacillin (7) and to a lesser extent with piperacillin tazobactam (2). Except for imipenem, trimethoprim sulfamethoxazoie and cefotaxime, all antimicrobial agents presented minor errors with both methodologies. Based upon the high rate of minor errors, we consider it is important to confirm results obtained with the standard technique (NCCLS), considering as presumptive those results from the blood culture bottles (D and d).

Hemocultivos: utilidad de los antibiogramas presuntivos / Blood cultures: use of presumptive antiobiograms

Mortality associated to bacteremia varies between 20 and 40 depending upon several factors, such as focus of infection, microorganism, host conditions, etc. It has also been documented that mortality may double when the patient does not receive antibiotic treatment to which the microorganism is susceptible. The objective of our work has been to determine the correlation between disk diffusion antibiogram according to NCCLS guidelines, from isolated colonies, and the one performed directly from the blood culture flask. During 1996, in the Institute of Cardiology and Cardiovascular Surgery (ICYCC) in Buenos Aires City, 81 episodes of bacteremia were studied. In every case, an antibiogram was carried out: 1) from the bottle: a- Directly (D), harvesting 20 microliters in Mueller Hinton agar, b- Diluted (d), previous centrifugation and Gram staining to adjust turbidity equivalent to 0.5 Mc Farland; 2) from isolated colonies, according to NCCLS guidelines. There were almost no major errors, except with two strains of Enterobacter cloacae versus cephalotin. The diluted method was not so convenient to read inhibition zones, especially with staphylococci. With gram-positive bacteria, the main problems appeared in the direct method with erythromycin, oxacillin and ciprofloxacin because of minor errors. With gram-negative bacteria, major errors were observed in the direct method, mainly with piperacillin (7) and to a lesser extent with piperacillin tazobactam (2). Except for imipenem, trimethoprim sulfamethoxazoie and cefotaxime, all antimicrobial agents presented minor errors with both methodologies. Based upon the high rate of minor errors, we consider it is important to confirm results obtained with the standard technique (NCCLS), considering as presumptive those results from the blood culture bottles (D and d).(AU)

[Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia]. / Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas.

Between February and September 1997, 6588 blood cultures at the Instituto de Cardiología y Cirugía Cardiovascular and Hospital de Niños Ricardo Gutiérrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3%) were monomicrobial episodes and 14 (4.7%) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10% CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7% to 4.7%. Taking into account the total number of bacteremias, only in 3 out of 294 (1%), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

[The microbiology laboratory in the diagnosis of bacteremia associated with catheters]. / El laboratorio de microbiología en el diagnóstico de la bacteriemia relacionada con los catéteres.

Catheter related sepsis is an outstanding problem in patients in every age group. The microbiological diagnosis should consider the main pathways of infection (catheter-skin interface, endoluminal). With this aim we analysed 1496 central and peripheral short term catheters and 119 episodes of catheter related bacteremia. Catheters were cultured according to the quantitative technique of Brun Buisson (QT), the semiquantitative technique of Maki (SQ) and qualitative broth culture (QL). The following results of sensitivity, specificity, positive predictive value, negative predictive value and Youden index were obtained: SQ = 87%, 88%, 40%, 99%, 0.75; QT (> or = 10(2) CFU/ml) = 88%, 89%, 43%, 99%, 0.77; QT (> or = 10(3) CFU/ml) = 77%, 92%, 48%, 97%, 0.69; QL = 94%, 68%, 20%, 99%, 0.62. Results of SQ and QT > or = 10(2) were comparable, nevertheless, the addition of QT to SQ increased the detection of bacteremia by 12.8%, while in the opposite situation the increase was 10%. According to this, it is advisable to combine routinely SQ and QT. Finally, in 42 episodes of bacteremia related to implanted catheters processed by quantitative differential culture of blood drawn through the catheter and blood drawn through the peripheral vein the relationships were: > 1000 in 79% of cases, between 100 and 1000 in 9% of cases and between 5 and 10 in just 5% of cases.

Aumento transitorio de fosfatasa alcalina sérica post trasplante hepático en un paciente pediátrico / Transient high alkaline phosphatase activity in serum of a pediatric patient after liver transplantation

En este estudio se presenta el caso de un paciente pediátrico que luego de ser sometido a un transplante hepático con donante vivo relacionado, presentó un cuadro de hiperfosfatasemia alcalina sérica. Se pone énfasis en la importancia de la utilización de la técnica de isoelectroenfoque para determinar el origen tisular del hallazgo mencionado

Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas / Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia

Between February and September 1997, 6588 blood cultures at the Instituto de CardiologÝa y CirugÝa Cardiovascular and Hospital de Niños Ricardo GutiÚrrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3) were monomicrobial episodes and 14 (4.7) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10 CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7 to 4.7. Taking into account the total number of bacteremias, only in 3 out of 294 (1), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.

Evaluación de la reincubación de hemocultivos positivos por el sistema BACT-ALERT para la detección de bacteriemias polimicrobianas / Evaluation of the reincubation of positive blood cultures for detection in the BACT-ALERT system for the detection of polymicrobial bacteremia

Between February and September 1997, 6588 blood cultures at the Instituto de CardiologYa y CirugYa Cardiovascular and Hospital de Niños Ricardo GutiUrrez were studied by using the Bact-Alert system (Organon Teknika) 341 contaminants and 294 episodes of bacteremia (600 samples) were analyzed. From these samples, 280 (95.3) were monomicrobial episodes and 14 (4.7) polymicrobial episodes. Positive blood cultures detected by the Bact-Alert system were processed and then reincubated during 7 days, when they were Gram stained and subcultured in blood agar, chocolate agar (both in 5-10 CO2), laked blood agar supplemented with hemin and vitamin K in anaerobic atmosphere (only anaerobic bottles) and CLDE (aerobic conditions). Following reincubation, 3 out of 14 polymicrobial bacteremias were detected, rising the level of detection from 3.7 to 4.7. Taking into account the total number of bacteremias, only in 3 out of 294 (1), a second microorganism was detected. Otherwise, in blood cultures where a contaminating microorganism was initially isolated, no further isolates representing a true bacteremia were recovered. Reincubation and terminal subculture of initially positive blood cultures did not provide relevant data in order to change therapeutic measures in the studied population. Due to the increase in costs and labor we consider that this methodology is not routinely advised.(AU)

Aumento transitorio de fosfatasa alcalina sérica post trasplante hepático en un paciente pediátrico / Transient high alkaline phosphatase activity in serum of a pediatric patient after liver transplantation

En este estudio se presenta el caso de un paciente pediátrico que luego de ser sometido a un transplante hepático con donante vivo relacionado, presentó un cuadro de hiperfosfatasemia alcalina sérica. Se pone énfasis en la importancia de la utilización de la técnica de isoelectroenfoque para determinar el origen tisular del hallazgo mencionado (AU)