[Effect of cyclophosphamide in experimental histoplasmosis in the rat]. / Acción de la ciclofosfamida en la histoplasmosis experimental de la rata.

Histoplasmosis is a fungal disease caused by the dimorphous fungus Histoplasma capsulatum (Hc). Cyclophosphamide (Cy) was used as an immunomodulator capable of modifying the course of the disease, as well as of regulating the mechanisms involved in T-lymphocyte mediated immune response. Rats were subjected to intracardiac inoculation of Hc followed by a fractionated treatment with a 100 mg/kg body weight dose of Cy on days +4, +5, +6, +7 and +11 pi. Until day 26 pi, treatment with Cy caused 85% mortality whereas no mortality was observed among animals only inoculated with Hc. On day 14 pi, the group of Hc animals showed a delayed hypersensitivity test (DH) of 26.60 + 13.96 as determined by the swelling of the leg. Conversely, DH was significantly depressed in rats inoculated with Hc and treated with Cy: 3.88 +/- 1.00 (p < 0.01). Colony forming units count in this group was 2020 CFU/g of spleen, and 24 CFU/g of spleen (p < 0.01) in controls. A macroscopic study of the organs revealed that the animals in the Hc+Cy group had spleenomegaly and lungs with granuloma and hemorrhagic spots. The controls only presented small lung abscesses. These findings lead to the conclusion that Cy causes a deterioration of cell mediated immune response which results in the manifestation of an acute, fatal experimental mycosis.

[Evaluation of alternative hemoculture tests for the diagnosis of early neonatal sepsis]. / Evaluación de pruebas alternativas al hemocultivo en el diagnóstico de la sepsis neonatal precoz.

In order to evaluate the diagnostic usefulness of coadjuvant tests such as external auditory canal swab culture and cultures from nasopharyngeal and gastric aspirates, and to determine the incidence and etiology of early neonatal sepsis (ENS) at our Unit, 90 newborn cases whose mothers experienced premature rupture of the membranes (PRM) were studied prospectively. Although a firm diagnosis requires positive blood cultures, the difficulty in recovering microorganisms and the trauma induced by sample collection in the baby justify the search for alternative diagnostic tests. Out of 2293 childbirths during 1991, 90 mothers (4%) had PRM more than 24 hours pre-partum, while 6.9/1000 (16/2293) developed ENS. In newborns from PMR mothers, ENS percentage was 3.3%, but increased to 5.5% in association with chorionamnionitis and reached 8.8% in premature cases. Among etiological ENS agents, Gram-positive microorganisms predominated (Table 1), particularly Staphylococcus aureus. Despite the finding that none of the coadjuvant assays (Table 2) had sufficient sensitivity or positive predictive value to identify all septic cases, they may prove useful to pinpoint newborns at high risk due to amniotic fluid exposure to infection or to chorioamnionitis.

Evaluación de pruebas alternativas al hemocultivo en el diagnóstico de la sepsis neonatal precoz. / [Evaluation of alternative hemoculture tests for the diagnosis of early neonatal sepsis]

In order to evaluate the diagnostic usefulness of coadjuvant tests such as external auditory canal swab culture and cultures from nasopharyngeal and gastric aspirates, and to determine the incidence and etiology of early neonatal sepsis (ENS) at our Unit, 90 newborn cases whose mothers experienced premature rupture of the membranes (PRM) were studied prospectively. Although a firm diagnosis requires positive blood cultures, the difficulty in recovering microorganisms and the trauma induced by sample collection in the baby justify the search for alternative diagnostic tests. Out of 2293 childbirths during 1991, 90 mothers (4

) had PRM more than 24 hours pre-partum, while 6.9/1000 (16/2293) developed ENS. In newborns from PMR mothers, ENS percentage was 3.3

, but increased to 5.5

in association with chorionamnionitis and reached 8.8

in premature cases. Among etiological ENS agents, Gram-positive microorganisms predominated (Table 1), particularly Staphylococcus aureus. Despite the finding that none of the coadjuvant assays (Table 2) had sufficient sensitivity or positive predictive value to identify all septic cases, they may prove useful to pinpoint newborns at high risk due to amniotic fluid exposure to infection or to chorioamnionitis.

[Haemophilus influenzae type B: subtyping of strains isolated from respiratory infections using the outer membrane protein profiles]. / Haemophilus influenzae tipo b: subtipificación de cepas aisladas de infecciones respiratorias mediante los perfiles de proteínas de la membrana externa.

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) applied to outer membrane protein (OMP), extracted by a micromethod, was employed to subtype H. influenza b type I. A total of 37 H. influenzae b strains were isolated from children under 4 years of age, either with lower acute respiratory infection (LARI), or asymptomatic carriers matched according sex, socioeconomic level and seasonality. Twenty seven out of the 37 H. influenzae b strains belonged to biotype I. On the basis of OMP profiles, these 27 were classified into 8 subtypes (Figs. 2, 3, 4 and 5). The probability of two randomly chosen isolates having different OMP profiles was 0.733. The subtype termed "a" showed the greatest relative frequency and was detected both in invasive strains and in those isolated from throat samples of LARI cases and healthy children. The use of 14% SDS-PAGE allowed de detection either of a 51kD or a 49kD, as well as 25-40kD proteins, in a single run (Fig. 1). Most subtype profiles showed the 51 kD protein. Growth conditions and extraction of OMPs by our modified micromethod provide a single and inexpensive procedure within the means of the average clinical laboratory. Besides, this test is much less time-consuming than classical assays. Jointly, biotyping , serotyping and OMP profile determination, proved a useful epidemiological tool to survey H. influenzae b infection.

Haemophilus influenzae tipo b: subtipificación de cepas aisladas de infecciones respiratorias mediante los perfiles de proteínas de la membrana externa. / [Haemophilus influenzae type B: subtyping of strains isolated from respiratory infections using the outer membrane protein profiles]

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) applied to outer membrane protein (OMP), extracted by a micromethod, was employed to subtype H. influenza b type I. A total of 37 H. influenzae b strains were isolated from children under 4 years of age, either with lower acute respiratory infection (LARI), or asymptomatic carriers matched according sex, socioeconomic level and seasonality. Twenty seven out of the 37 H. influenzae b strains belonged to biotype I. On the basis of OMP profiles, these 27 were classified into 8 subtypes (Figs. 2, 3, 4 and 5). The probability of two randomly chosen isolates having different OMP profiles was 0.733. The subtype termed [quot ]a[quot ] showed the greatest relative frequency and was detected both in invasive strains and in those isolated from throat samples of LARI cases and healthy children. The use of 14

SDS-PAGE allowed de detection either of a 51kD or a 49kD, as well as 25-40kD proteins, in a single run (Fig. 1). Most subtype profiles showed the 51 kD protein. Growth conditions and extraction of OMPs by our modified micromethod provide a single and inexpensive procedure within the means of the average clinical laboratory. Besides, this test is much less time-consuming than classical assays. Jointly, biotyping , serotyping and OMP profile determination, proved a useful epidemiological tool to survey H. influenzae b infection.

Perfiles de resistencia de las distintas especies del género Staphylococcus frente a quince antimicrobianos de uso clínico / Resistance profiles of the various species of the genus Staphylococcus to 15 clinically-used antimicrobials

Se estudiaron 78 cepas de distinas especies del género Staphylococcus (29 S. aureus, 48 Staphylococcus coagulasa-negativos y 1 cepa de S. intermedius) para conocer los perfiles de resistencia frente a quince antimicrobianos de uso clínico. De las 48 cepas de Staphylococcus coagulasa-negativos estudiadas, 8 (4 S. epidermidis, 1 S. haemolyticus, 1 S. hominis, 2 S. xylosus) presentaron un perfil de resistencia semejante a S. aureus frente a antibióticos beta-lactámicos, aminoglicósidos, cloranfenicol y fosfomicina. Diez de las restantes cepas de Staphylococcus coagulasa negativos estudiadas presentaron actividad de beta-lactamasa. A pesar que las 7 cepas de S. saprophyticus estudiadas fueron beta-lactamasa-negativas aún luego de la inducción, la concentración inhibitoria mínima a penicilina G fue ligeramene mayor en comparación al valor obtenido en las cepas beta-lactamasas-negativas del resto de las especies. La resistencia a eritromicina fue coincidente con la resistencia a clindamicina en la mayoría de las especies coagulasa-negativas estudiadas, y la resistencia a aminoglicósidos parece ser mediada por las mismas enzimas modificantes en todo el género. Todo el género fue sensible a vancomicina. La rifampicina fue muy activa contra todas las cepas de Staphylococcus coagulasa-negativas. Las cepas de S. aureus rifampicina-resistentes fueron todas resistentes a oxacilina, aunque con respecto al resto de antimicrobianos probados, el patrón de resistencia fue diferente para cada cepa ...

Perfiles de resistencia de las distintas especies del género Staphylococcus frente a quince antimicrobianos de uso clínico / Resistance profiles of the various species of the genus Staphylococcus to 15 clinically-used antimicrobials

Se estudiaron 78 cepas de distinas especies del género Staphylococcus (29 S. aureus, 48 Staphylococcus coagulasa-negativos y 1 cepa de S. intermedius) para conocer los perfiles de resistencia frente a quince antimicrobianos de uso clínico. De las 48 cepas de Staphylococcus coagulasa-negativos estudiadas, 8 (4 S. epidermidis, 1 S. haemolyticus, 1 S. hominis, 2 S. xylosus) presentaron un perfil de resistencia semejante a S. aureus frente a antibióticos beta-lactámicos, aminoglicósidos, cloranfenicol y fosfomicina. Diez de las restantes cepas de Staphylococcus coagulasa negativos estudiadas presentaron actividad de beta-lactamasa. A pesar que las 7 cepas de S. saprophyticus estudiadas fueron beta-lactamasa-negativas aún luego de la inducción, la concentración inhibitoria mínima a penicilina G fue ligeramene mayor en comparación al valor obtenido en las cepas beta-lactamasas-negativas del resto de las especies. La resistencia a eritromicina fue coincidente con la resistencia a clindamicina en la mayoría de las especies coagulasa-negativas estudiadas, y la resistencia a aminoglicósidos parece ser mediada por las mismas enzimas modificantes en todo el género. Todo el género fue sensible a vancomicina. La rifampicina fue muy activa contra todas las cepas de Staphylococcus coagulasa-negativas. Las cepas de S. aureus rifampicina-resistentes fueron todas resistentes a oxacilina, aunque con respecto al resto de antimicrobianos probados, el patrón de resistencia fue diferente para cada cepa ... (AU)

[Resistance profiles of the various species of the genus Staphylococcus to 15 clinically-used antimicrobials]. / Perfiles de resistencia de las distintas especies del género Staphylococcus frente a quince antimicrobianos de uso clínico.

A total of 78 strains of 11 species of Staphylococcus genus (29 S. aureus, 48 Staphylococcus coagulase-negative and 1 S. intermedius strain,) were studied in order to determine the resistance patterns to fifteen commonly used antimicrobial agents. Out of 48 Staphylococcus coagulase-negative strains studied, 8 (4/15 S. epidermidis, 1/10 S. hominis, 1/6 S. haemolyticus, 2/3 S. xylosus) showed resistance patterns similar to that of S. aureus strains against beta-lactam antibiotics, aminoglycosides, chloramphenicol and fosfomycin, and 10 exhibit beta-lactamase-activity. Although the 7 S. saprophyticus strains assayed were beta-lactamase-negative by the chromogenic cephalosporin method after induction, the penicillin G minimal inhibitory concentration values were slightly higher than those obtained with other beta-lactamase-negative species. The susceptibilities to erythromycin and clindamycin suggested that macrolides-lincosamides-streptogramin type B (MLS) resistance was present in a large number of Staphylococcus coagulase-negative strains. In all the Staphylococcus genus, the aminoglycosides resistance seems to be mediated by the same aminoglycosides modifying-enzymes. Vancomycin was very active against the 11 species assayed. Rifampicin was effective with all Staphylococcus coagulase-negative strains. The S. aureus rifampicin-resistant were also resistant to oxacillin, and variable against aminoglycosides, chloramphenicol, fosfomycin, erythromycin and clindamycin. Only 5 strains were resistant to trimethoprim-sulfamethoxazole (TMS), 1 S. aureus oxacillin-susceptible, 1 S. aureus oxacillin-resistant, 2 S. xylosus and 1 S. warneri strains.

Perfiles de resistencia de las distintas especies del género Staphylococcus frente a quince antimicrobianos de uso clínico. / [Resistance profiles of the various species of the genus Staphylococcus to 15 clinically-used antimicrobials]

A total of 78 strains of 11 species of Staphylococcus genus (29 S. aureus, 48 Staphylococcus coagulase-negative and 1 S. intermedius strain,) were studied in order to determine the resistance patterns to fifteen commonly used antimicrobial agents. Out of 48 Staphylococcus coagulase-negative strains studied, 8 (4/15 S. epidermidis, 1/10 S. hominis, 1/6 S. haemolyticus, 2/3 S. xylosus) showed resistance patterns similar to that of S. aureus strains against beta-lactam antibiotics, aminoglycosides, chloramphenicol and fosfomycin, and 10 exhibit beta-lactamase-activity. Although the 7 S. saprophyticus strains assayed were beta-lactamase-negative by the chromogenic cephalosporin method after induction, the penicillin G minimal inhibitory concentration values were slightly higher than those obtained with other beta-lactamase-negative species. The susceptibilities to erythromycin and clindamycin suggested that macrolides-lincosamides-streptogramin type B (MLS) resistance was present in a large number of Staphylococcus coagulase-negative strains. In all the Staphylococcus genus, the aminoglycosides resistance seems to be mediated by the same aminoglycosides modifying-enzymes. Vancomycin was very active against the 11 species assayed. Rifampicin was effective with all Staphylococcus coagulase-negative strains. The S. aureus rifampicin-resistant were also resistant to oxacillin, and variable against aminoglycosides, chloramphenicol, fosfomycin, erythromycin and clindamycin. Only 5 strains were resistant to trimethoprim-sulfamethoxazole (TMS), 1 S. aureus oxacillin-susceptible, 1 S. aureus oxacillin-resistant, 2 S. xylosus and 1 S. warneri strains.