[Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients]. / Estudio microbiológico de bacteriemias y fungemias en pacientes en hemodiálisis crónica.

Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients. Bloodstream infections are the second cause of death in patients in chronic hemodialysis (CHD), and the knowledge of the epidemiology is useful to establish proper empiric therapies. The aim of this study was to evaluate the frequency and distribution of microorganisms, in bacteremia and fungemia in 530 patients in CHD. Two hundred and forty eight blood culture series from 114 patients with suspected bacteremia were processed; 44% of them were positive from which 71% (n=78) were clinically significative and belonged to 58 patients. Sixty eight percent of these isolates were gram-positive cocci (n:53), and 22% gram-negative rods (n:17). Staphylococcus aureus was the most prevalent pathogen showing 23% of methicillin-resistance. Candida spp. was the fourth pathogen most common in frequency.

Estudio microbiológico de bacteriemias y fungemias en pacientes en hemodiálisis crónica / [Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients]

Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients. Bloodstream infections are the second cause of death in patients in chronic hemodialysis (CHD), and the knowledge of the epidemiology is useful to establish proper empiric therapies. The aim of this study was to evaluate the frequency and distribution of microorganisms, in bacteremia and fungemia in 530 patients in CHD. Two hundred and forty eight blood culture series from 114 patients with suspected bacteremia were processed; 44

(n=78) were clinically significative and belonged to 58 patients. Sixty eight percent of these isolates were gram-positive cocci (n:53), and 22

gram-negative rods (n:17). Staphylococcus aureus was the most prevalent pathogen showing 23

of methicillin-resistance. Candida spp. was the fourth pathogen most common in frequency.

Estudio microbiológico de bacteriemias y fungemias en pacientes en hemodiálisis crónica. / [Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients]

Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients. Bloodstream infections are the second cause of death in patients in chronic hemodialysis (CHD), and the knowledge of the epidemiology is useful to establish proper empiric therapies. The aim of this study was to evaluate the frequency and distribution of microorganisms, in bacteremia and fungemia in 530 patients in CHD. Two hundred and forty eight blood culture series from 114 patients with suspected bacteremia were processed; 44

of them were positive from which 71

(n=78) were clinically significative and belonged to 58 patients. Sixty eight percent of these isolates were gram-positive cocci (n:53), and 22

gram-negative rods (n:17). Staphylococcus aureus was the most prevalent pathogen showing 23

of methicillin-resistance. Candida spp. was the fourth pathogen most common in frequency.

Susceptibility of Candida species to fluconazole assayed by a disk diffusion method with automated reading versus a microdilution method.

In vitro susceptibilities of 290 isolates of Candida spp to fluconazole were evaluated by a new NCCLS M44-P agar disk diffusion method that was read and interpreted automatically by the BIOMIC image-analysis plate reader system. Disk test results were compared to results obtained by a modified NCCLS M27-A broth microdilution method using RPMI-1640 supplemented with 2% dextrose. Overall agreement between both methods was 90.0%. Category agreement between the broth and disk test results for susceptible, susceptible dose-dependent and resistant disk results were 99.6%, 19.05% and 52.17%, respectively. No very major discrepancies, 1.03% major discrepancies, and 8.97% minor discrepancies were observed between results of the two test methods. This analysis suggests that results from both methods correlate highly for Candida strains susceptible to fluconazole. The lower agreement between the two methods for resistant and susceptible dose-dependent isolates was due to strains near or on that breakpoint, different media (Mueller-Hinton vs RPMI), agar vs broth, 80% vs 50% endpoints, and trailing growth near the endpoints.

Susceptibility of Candida species to fluconazole assayed by a disk diffusion method with automated reading versus a microdilution method

In vitro susceptibilities of 290 isolates of Candida spp to fluconazole were evaluated by a new NCCLS M44-P agar disk diffusion method that was read and interpreted automatically by the BIOMIC image-analysis plate reader system. Disk test results were compared to results obtained by a modified NCCLS M27-A broth microdilution method using RPMI-1640 supplemented with 2

. Category agreement between the broth and disk test results for susceptible, susceptible dose-dependent and resistant disk results were 99.6

major discrepancies, and 8.97

minor discrepancies were observed between results of the two test methods. This analysis suggests that results from both methods correlate highly for Candida strains susceptible to fluconazole. The lower agreement between the two methods for resistant and susceptible dose-dependent isolates was due to strains near or on that breakpoint, different media (Mueller-Hinton vs RPMI), agar vs broth, 80

endpoints, and trailing growth near the endpoints.

Susceptibility of Candida species to fluconazole assayed by a disk diffusion method with automated reading versus a microdilution method.

In vitro susceptibilities of 290 isolates of Candida spp to fluconazole were evaluated by a new NCCLS M44-P agar disk diffusion method that was read and interpreted automatically by the BIOMIC image-analysis plate reader system. Disk test results were compared to results obtained by a modified NCCLS M27-A broth microdilution method using RPMI-1640 supplemented with 2

dextrose. Overall agreement between both methods was 90.0

. Category agreement between the broth and disk test results for susceptible, susceptible dose-dependent and resistant disk results were 99.6

, 19.05

and 52.17

, respectively. No very major discrepancies, 1.03

major discrepancies, and 8.97

minor discrepancies were observed between results of the two test methods. This analysis suggests that results from both methods correlate highly for Candida strains susceptible to fluconazole. The lower agreement between the two methods for resistant and susceptible dose-dependent isolates was due to strains near or on that breakpoint, different media (Mueller-Hinton vs RPMI), agar vs broth, 80

vs 50

endpoints, and trailing growth near the endpoints.

[Comparative study of the Candida albicans genotypes isolated from immunocompromised patients and health carriers]. / Estudio comparativo de los genotipos de Candida albicans aislados de pacientes inmunocomprometidos y portadores sanos.

The aim of this study is to compare Candida albicans strain genotype isolates from oral cavity of immunocompromised patients due to different immunologic impairments with apparently normal carriers. Four populations were studied: 1) HIV positive hospitalized patients, 2) HIV negative immunocompromised patients (leukemia, lymphoma, organ transplant recipients), 3) drug addicts prior to AIDS pandemia in Argentina, 4) apparently normal carriers. DNA extracted was digested with the enzyme Eco RI, electrophoresed, transferred to nitrocellulose membrane and hybridized with the 27A probe labelled with 32P. The comparison between the profiles obtained permitted the differentiation of 16 genotypes. The distribution of the strains led to the conclusion that: a) all the isolated strains from AIDS patients were closely related and distributed in only three genotypes (1, 3, 11); b) a major genetic relationship between the isolates from AIDS patients and HIV negative immunocompromised patients was observed; c) strains from carriers showed a minor genetic similarity with those obtained from AIDS patients; d) characteristic profiles belonging to any of the studied groups were not found; e) significant genomic changes have not been observed during the last twenty years.

Estudio comparativo de los genotipos de Candida albicans aislados de pacientes inmunocomprometidos y portadores sanos / [Comparative study of the Candida albicans genotypes isolated from immunocompromised patients and health carriers]

The aim of this study is to compare Candida albicans strain genotype isolates from oral cavity of immunocompromised patients due to different immunologic impairments with apparently normal carriers. Four populations were studied: 1) HIV positive hospitalized patients, 2) HIV negative immunocompromised patients (leukemia, lymphoma, organ transplant recipients), 3) drug addicts prior to AIDS pandemia in Argentina, 4) apparently normal carriers. DNA extracted was digested with the enzyme Eco RI, electrophoresed, transferred to nitrocellulose membrane and hybridized with the 27A probe labelled with 32P. The comparison between the profiles obtained permitted the differentiation of 16 genotypes. The distribution of the strains led to the conclusion that: a) all the isolated strains from AIDS patients were closely related and distributed in only three genotypes (1, 3, 11); b) a major genetic relationship between the isolates from AIDS patients and HIV negative immunocompromised patients was observed; c) strains from carriers showed a minor genetic similarity with those obtained from AIDS patients; d) characteristic profiles belonging to any of the studied groups were not found; e) significant genomic changes have not been observed during the last twenty years.

Estudio comparativo de los genotipos de Candida albicans aislados de pacientes inmunocomprometidos y portadores sanos. / [Comparative study of the Candida albicans genotypes isolated from immunocompromised patients and health carriers]

The aim of this study is to compare Candida albicans strain genotype isolates from oral cavity of immunocompromised patients due to different immunologic impairments with apparently normal carriers. Four populations were studied: 1) HIV positive hospitalized patients, 2) HIV negative immunocompromised patients (leukemia, lymphoma, organ transplant recipients), 3) drug addicts prior to AIDS pandemia in Argentina, 4) apparently normal carriers. DNA extracted was digested with the enzyme Eco RI, electrophoresed, transferred to nitrocellulose membrane and hybridized with the 27A probe labelled with 32P. The comparison between the profiles obtained permitted the differentiation of 16 genotypes. The distribution of the strains led to the conclusion that: a) all the isolated strains from AIDS patients were closely related and distributed in only three genotypes (1, 3, 11); b) a major genetic relationship between the isolates from AIDS patients and HIV negative immunocompromised patients was observed; c) strains from carriers showed a minor genetic similarity with those obtained from AIDS patients; d) characteristic profiles belonging to any of the studied groups were not found; e) significant genomic changes have not been observed during the last twenty years.

Comparative in vitro bactericidal activity between cefepime and ceftazidime, alone and associated with amikacin, against carbapenem-resistant Pseudomonas aeruginosa strains.

Fifteen unique isolates of carbapenem-resistant Pseudomonas aeruginosa were selected for time-kill studies to assess the bactericidal activity of cefepime (CFP) and ceftazidime (CZD) (at 4 and 16 microg/mL), alone and associated with amikacin (AMK) (4 microg/mL). CFP proved more active than CZD (p < 0.05, Student's t test). Bactericidal activity after 24-h incubation was only achieved by the combination of CFP (16 microg/mL) plus AMK. The higher in vitro activity of cefepime over that of ceftazidime against imipenem-resistant P. aeruginosa strains highlights the differences of these drugs beyond Enterobacterspp. and Staphylococcus aureus.

Comparison of several methods to determine methicillin-resistance in Staphylococcus aureus with focus on borderline strains.

We compared the performance of several phenotypic tests to detect methicillin-resistant Staphylococcus aureus, with special focus on borderline strains. The reliability of the agar screen oxacillin and BBL Crystal tests was asserted for all methicillin-susceptible (n = 25), -resistant (n = 29) and borderline beta-lactamase-hyperproducer (n = 10) strains. Whereas these tests failed to detect 4 of 5 rare borderline strains containing few cells with high-level methicillin resistance (i.e., a frequency of 10(-7)-10(-8)), a "two-temperature" disk diffusion method, performed simultaneously at 35 and 42 degrees C, detected all of such strains.

Species belonging to the "Streptococcus milleri" group: antimicrobial susceptibility and comparative prevalence in significant clinical specimens.

The association between the three species belonging to the "Streptococcus milleri" group and different sites of isolation was examined for 73 successive strains recovered from clinically significant, purulent infections. Susceptibility testing was performed on 64 of these strains. The present study supports the association of particular species with different clinical sources. Susceptibility data suggest that emerging penicillin resistance among Streptococcus anginosus and Streptococcus intermedius isolates may represent a potential clinical problem in the therapeutic management of infections caused by these species.

In vitro susceptibility of Ureaplasma urealyticum and Mycoplasma hominis isolates in Argentina.

OBJECTIVE: Our goal was to determine the in vitro susceptibility of Ureaplasma urealyticum and Mycoplasma hominis isolates to several antibiotics in Argentina. METHODS: Ninety-four strains of U. urealyticum and 18 strains of M. hominis isolated from cervical and urethral specimens were studied. Broth microdilution and agar dilution tests for minocycline, tetracycline, erythromycin, ciprofloxacin, and ofloxacin were performed. RESULTS: Both methods proved to be reliable and reproducible for U. urealyticum and M. hominis, with no major differences in results. The U. urealyticurn strains were inhibited by erythromycin at MICs ranging from < or =0.5 to >8 micro/ml. Ofloxacin showed the highest activity against this latter organism. No differences between tetracycline and minocycline MICs were observed with U. urealyticum. Two M. hominis strains displaying high MICs both to tetracycline and to minocycline were detected. CONCLUSIONS: The emerging resistance of mycoplasmas to certain antibiotics emphasizes the need to undertake further surveillance studies on the clinical isolates of such organisms.

Características epidemiológicas de 71 casos de criptococosis diagnosticados en diferentes centros asistenciales de la ciudad de Buenos Aires y sus alrededores, durante 1991 / Epidemiological characteristics of 71 cases of cryptococcosis diagnosed in different medical centers of the city of Buenos Aires and its suburbs, in 1991

Se estudiaron algunas características epidemiológicas de 71 casos de criptococosis diagnosticados en 8 centros asistenciales de la ciudad de Buenos Aires y el Gran Buenos Aires, durante 1991. Los hospitales Muñiz y Fernández, comunicaron cerca del 85 por ciento de los casos. El 89 por ciento de los pacientes era de sexo masculino. Las causas predisponentes fueron SIDA (66 casos), transplante renal (2 casos), hepatopatía autoinmune tratada con corticoides, diabetes descompensada y embarazo/puerperio. La mediana de la edad fue de 27 años en la población total (rango 19-62), de 27 años en los casos asociados al SIDA (rango 19-50) y de 50 años en los no asociados a esa enfermedad (rango 24-62). El 56 por ciento de los pacientes se ubicó en el grupo etario de 20-29 años de edad. Una estimación indirecta permite suponer que el porcentaje de pacientes con SIDA que padecieron criptococosis durante 1991 en el área en estudio fue de 25,88 por ciento. El 100 por ciento de 32 casos de Cryptococcus neoformans aisladas de los pacientes fueron identificadas como variedad neoformans. La criptococosis aumenta año a año su incidencia en nuestro medio, paralelamente con su causa predisponente más importante, el SIDA. Su transformación potencial en un problema sanitario, debe alertar a la autoridades competentes

Características epidemiológicas de 71 casos de criptococosis diagnosticados en diferentes centros asistenciales de la ciudad de Buenos Aires y sus alrededores, durante 1991 / Epidemiological characteristics of 71 cases of cryptococcosis diagnosed in different medical centers of the city of Buenos Aires and its suburbs, in 1991

Se estudiaron algunas características epidemiológicas de 71 casos de criptococosis diagnosticados en 8 centros asistenciales de la ciudad de Buenos Aires y el Gran Buenos Aires, durante 1991. Los hospitales Muñiz y Fernández, comunicaron cerca del 85 por ciento de los casos. El 89 por ciento de los pacientes era de sexo masculino. Las causas predisponentes fueron SIDA (66 casos), transplante renal (2 casos), hepatopatía autoinmune tratada con corticoides, diabetes descompensada y embarazo/puerperio. La mediana de la edad fue de 27 años en la población total (rango 19-62), de 27 años en los casos asociados al SIDA (rango 19-50) y de 50 años en los no asociados a esa enfermedad (rango 24-62). El 56 por ciento de los pacientes se ubicó en el grupo etario de 20-29 años de edad. Una estimación indirecta permite suponer que el porcentaje de pacientes con SIDA que padecieron criptococosis durante 1991 en el área en estudio fue de 25,88 por ciento. El 100 por ciento de 32 casos de Cryptococcus neoformans aisladas de los pacientes fueron identificadas como variedad neoformans. La criptococosis aumenta año a año su incidencia en nuestro medio, paralelamente con su causa predisponente más importante, el SIDA. Su transformación potencial en un problema sanitario, debe alertar a la autoridades competentes (AU)

Abscess caused by vancomycin-resistant Lactobacillus confusus.

Several isolates of vancomycin-resistant Lactobacillus confusus from human sources have been described, but to our knowledge, no well-documented infection attributable to this organism has been published. A thumb abscess caused by this bacterium in a healthy 49-year-old male is reported here. He was successfully treated by surgical drainage and cephalothin.