[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%.

[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%.

[Identification of strains of beta-hemolytic streptococci of groups A, B, C, and G by coagglutination]. / Identificación de cepas de estreptococos betahemolíticos de los grupos A, B, C y G por coaglutinación.

A study was conducted on the coagglutination (CoA) technique in the serogrouping of betahemolytic streptococci of the groups A, B, C and G, previously identified by physiological tests and the agar immunodiffusion technique. This technique was used as a reference test and, according to its results, it can be stated that the CoA technique allowed for the serological grouping in 95.7% of the strains. The CoA technique was assessed by using reactions prepared in our laboratories and the commercial kit Phadebact.