[A novel immunization schedule for obtaining anti-LPS Haemophilus influenzae type b antibodies]. / Novedoso esquema de inmunización para la obtención de anticuerpos anti-LPS de Haemophilus influenzae tipo b.

A novel immunization schedule was tested to increase antibodies to Haemophilus influenzae type B in which a 0.5% formaldehyde-inactivated cellular antigen and a partially purified lipopolysacharid antigen obtained from a selective precipitation with organic solvents were combined as immunogens. High specificity and biological activity antibodies with titers up to 1:256 were obtained by counterinmunoelectrophoresis; they were purified through a selective precipitation with ammonium sulphate and an ion-exchange chromatography using a DEAE-Sapharose column. The method proposed in this paper facilitates the production of purified antibodies useful for the improvement of serological diagnosis and H. influenzae b strain serotyping techniques.

[Production and partial purification of the main hemolysin (pneumolysin) of Streptococcus pneumoniae]. / Producción y purificación parcial de la hemolisina principal (Neumolisina) de Streptococcus pneumoniae.

The capacity of 36 Cuban strains of Streptococcus pneumoniae to produce pneumolysin was studied, and 94.4% of them were determined to be producers of that enzyme. One of the best producers was cultured at a great scale and the pneumolysin found in the supernatan was partially purified through an ion-exchange chromatography in mono-Q column. This method made it possible to recover the enzyme whose purity level increased by 4.39 with 100% output.

[Circulating Haemophilus influenzae in Cuba. Characterization of strains isolated from meningitis]. / Haemophilus influenzae circulantes en Cuba. Caracterización de cepas aisladas de meningitis.

Haemophilus influenzae B(Hib) is often associated with serious systemic infections in children under 5 years of age. Since 1993, it is the most frequent agent isolated in meningoencephalitis. All the strains isolated in the country have been characterized in the National Reference Laboratory at the "Pedro Kourí" Tropical Medicine Institute. Results revealed that 97% of strains isolated from bacterial meningoencephalitis in Cuba during the period 1993-1995 corresponded to serotype B, 0.6% to serotype A and 2.4 not belong to any serotype. The classification of serotype B-strains into biotypes proved that 76% was biotype I and 21% biotype II, 8 to biotype III and 1.2% was biotype V. This study found the following resistance to ampicillin 40%, to chloranphenicol 43.3%, sulpha metoxazol 36%, trimetroprim 37.3% and tetracycline 31%.

[The evaluation of the specific type of capsular polysaccharide of Cryptococcus neoformans as an immunogen and positive-control antigen]. / Evaluación del polisacárido capsular tipo específico de Cryptococcus neoformans como inmunógeno y antígeno control positivo.

The specific type of capsular polysaccharide of an autochthonous strain of Cryptococcus neoformans var. neoformans was obtained by using the method of selective precipitation with hexadimethrine bromide. The capsular polysaccharide was matched to lamb's erythrocytes and it was used as an immunogen in rabbits. Antibody titres of up to 1:32 were attained. Doble serial dilutions of the capsular polysaccharide were evaluated as positive control antigen by contraimmunoelectrophoresis, latex and ELISA techniques, showing biological activity.

[A growth supplement for "fastidious germs"]. / Suplemento de crecimiento para "gérmenes fastidiosos".

A growth supplement for "fastidious germs" was produced at the Laboratory of Acute Respiratory Infections of "Pedro Kourí" Institute of Tropical Medicine. This supplement was studied by computerized optic spectrophotometry, and chemical composition was determined. The efficacy of this supplement for the culture of Haemophilus influenzae type b, was evidenced using 100 strains, and it was proven that it can be used in concentrations raging from 1 to 10%.