Eduardo Osório Cisalpino

Six years' experience in treatment of chromomycosis with 5-fluorocytosine.

Twenty‐three patients with chromomycosis were treated with oral 5‐fluorocytosine for periods ranging from 2 to 67 months. Sixteen were considered cured, after 3 consecutive monthly controls showing healing of the lesions and absence of fungi in mycologic and histopathologic examinations of biopsy specimens. Seven, in spite of initial clinical improvement, showed resistance to treatment. Associated treatment with amphotericin B, calciferol or thiabendazole failed to help patients resistant to 5‐fluorocytosine. Resistance seems to occur especially in those with long‐standing lesions or widespread involvement.

Extraction, partial purification and characterization of a bacteriocin (fragilicin) produced by a strain of Bacteroides fragilis isolated from Callithrix penicillata

A strain of Bacteroides fragilis, isolated from the marmoset Callithrix penicillata, produced protein(s) with bacteriocin activity (fragicilin). Two active fractions (36 and 150 kDa) were isolated by chromatography. The bacteriocin exhibited iso- and heteroantagonism. It remained stable between pH 3 and 10 and at 60 degrees C for 24 h. Pronase, trypsin, proteinase K and type VII protease inactivated the bacteriocin, giving evidence of its protein nature.

Bacteriocin-like activity of Bacteriodes fragilis group isolated from marmosets

The ability of strains of the B. fragilis group, isolated from the oral cavity and intestine of marmosets, to produce bacteriorin-like substances in solid medium, in terms of auto-, iso- and heteroantagonism, was evaluated. Antagonistic activity was exhibited by 52% of the intestinal strains, 3 of which showed autoantagonistic activity. Three out of 9 oral strains isolated, tested against themselves, showed simultaneous isoantagonism to 4 indicator strains; but not autoantagonism. The same 9 oral strains, when tested against 16 reference strains, revealed interspecific activity only against 2 Gram-positive microorganisms. Higher activity, evaluated by the size of the inhibition halo, was observed in BHI-S agar, and greatest inhibition was obtained after 72 h of incubation.

Partial biochemical characterization of fiveParacoccidioides brasiliensis strains

The yeast forms of four strains ofParacoccidioides brasiliensis (SN, 2, 18, and 192), maintained in the laboratory for a long period of time, and a recent isolate of this fungus (JT-1) were cultured in a synthetic medium. Cell masses of each strain, in exponential growth phase, were obtained and lyophilized for partial analysis of their biochemical composition. The lipids of the five strains were extracted, purified, and analyzed in relation to the presence of sterols, phospholipids, glycolipids, and lipoproteins. The material withdrawn during the purification phase (“supernatant of lipid purification”) was subjected to protein and carbohydrate measurements. Another subfraction, lipid-free yeast, was analyzed after cell rupture by sonication, in relation to protein and carbohydrate total contents. The results showed significant differences in the measurements of total lipids (6.6–13.2 mg%), phospholipids (0.19–0.77 mg%) and glycolipids (0.14–0.42 mg%) among the five strains. Sterol analysis revealed the presence of ergosterol, lanosterol, and squalene in all of the samples. The measurements carried out on the supernatants of lipid purification and in the lipid-free yeasts also showed differences among the studied strains, particularly in relation to total carbohydrate content, which was significantly higher in the recent isolate of the fungus (JT-1). As a whole, this study revealed the existence of relevant biochemical differences among these differentParacoccidioides brasiliensis strains.

Isolation and identification of strains of Bacteroides fragilis group from the digestive tract of Callithrix penicillata marmosets

Thirty-five strains of the Bacteroides fragilis group were isolated from oral and intestinal samples from 5 wild caught, captive Callithrix penicillata. Nine oral strains of Bacteroides fragilis (7) and Bacteroides distasonis (2), and 26 intestinal strains of Bacteroides fragilis (14) and Bacteroides distasonis (12) were identified.

Biochemical analysis of the methylic antigen of Paracoccidioides brasiliensis

Yeast forms of five strains of Paracoccidioides brasiliensis (SN, 2, 18, 192 and JT-1) were cultured in a synthetic medium for obtaining methylic antigens. These antigens were lyophilized and studied for each strain, to determine their partial biochemical composition, through measurements of total lipid, protein and carbohydrate contents. Lipids of methylic antigens were purified and analysed for sterols, phospholipids, glycolipids, lipoproteins, and partial characterization of sterols. Significant differences were found among antigenic preparations derived from distinct P. brasiliensis strains, in relation to the quantitative determinations. On the other hand, sterol analysis revealed the presence of ergosterol, lanosterol and squalene in all samples. The diversity verified in the biochemical characteristics of antigens derived from different P. brasiliensis strains, confirm the need of using a pool of fungal samples in order to produce antigen preparations for serological procedures without hampering their sensitivity.

Haematological alterations induced by biochemical fractions of Paracoccidioides brasiliensis in mice

Zusammenfassung. Von Paracoccidioides brasiliensis wurden biochemische Faktionen zur experimentellen Inokulation in Mäuse und zur hämatologischen Analyse hergestellt. Die geprüften Präparationen waren: Abgetötete ganze Pilzzellen, Ultraschall‐Homogenat der Pilzzellen, Lipidextrakt, Überstand der Lipidausfällung, lipidfreie Ganzzellen, lipidfreies Ultraschall‐Homogenat. Ausgangsmaterial der sechs Fraktionen waren lyophilisierte Zellen der Hefephase eines frischen P. brasiliensis‐Isolats sowie eines Pools aus vier langfristig aufbewahrten Laborstämmen. Unterschiedliche Dosen dieser 12 Fraktionen wurden Mäusen intraperitoneal inokuliert und 30 Tage spärer die hämatologische Analyse durchgeführt. Im roten Blutbild wurden keine signifikanten Änderungen gefunden. Im weißen Blutbild fanden sich jedoch beträchtliche Veränderungen, wie Leukopenie, relative Neutrophilie und Lymphopenie. Eine Thrombozytose trat in weiten Bereichen auf. Die beobachteten hämatologischen Veränderungen waren dosisabhängig ohne Beziehung zur biochemischen Beschaffenheit der einzelnen Fraktionen. Zwischen den Präparaten aus dem Frischisolat und aus den Laborstämmen wurde kein Unterschied in den hämatologischen Befunden gesehen.

Antimicrobial resistance and plasmid detection in strains of the Bacteroides fragilis group

Resistant populations of the Bacteroides fragilis group bacteria (two reference ones and two isolated from human and Callithrix penicillata marmoset) were obtained by the gradient plate technique, to clindamycin, penicillin G, metronidazole and mercuric chloride. All the four tested strains were originally susceptible to the four antimicrobial drugs at the breakpoint used in this study. MICs determination for the four cultures gave constant values for each antimicrobial, on the several steps by the gradient plate technique. The intestinal human B. fragilis strains showed three DNA bands, that could be representative of only two plasmids in the closed covalently circular (CCC) form with molecular weights of approximately 25 and 2.5 Md. The results do not permit an association between the presence of plasmid in the human strain with the susceptibility to the studied drugs. The four strains were beta-lactamase negative in the two methods used, and no particular chromosomal genetic resistance marker was demonstrated. The resistance (MIC) observed, after contact with penicillin G and mercuric chloride, were two-fold in the four tested strains.

Testes de susceptibilidade de agentes da cromomicose à 5-fluorocitosina e ao butil-simpatol (Vasculat)

The sensitivity of strains isolated from patients with chromomycosis was tested in relation to 5-fluorocitosine and butyl-simpatol (Vasculat); some strains were resistant to fluorocitosine, even in the concentration of 100 mcg/ml and all of them showed complete resistance to butyl-simpatol.