Comparison of conventional ribotyping and PCR-RFLP ribotyping for the analysis of endemic strains of Neisseria meningitidis isolated in a local community over 7 years.

Conventional ribotyping was compared with the PCR amplification of the intergenic spacer region between 16S and 23S rRNA genes (PCR-RFLP ribotyping) when applied to the subtyping of sporadic Neisseria meningitidis strains. Thirty isolates out of a total of 36 meningococcal disease cases, reported as having occurred in a particular community over a 7-year endemic period, were analyzed by each of the methods. Only ribotyping with three restriction enzymes (EcoRI, ClaI and XhoI) gave acceptable discriminatory power for short-term epidemiological purposes. We conclude that conventional ribotyping is a suitable method for typing sporadic meningococcal strains and that it cannot be replaced by the more straightforward PCR-RFLP ribotyping method.

Human intestinal infection due to coccidia in Mozambique: two cases.

A case of intestinal infection by Cryptosporidium parvum and another of intestinal Isospora belli infection, both in AIDS patients, are described. The two patients presented pulmonary tuberculosis symptoms and watery diarrhoea. Modified Ziehl-Neelsen stain of stools gave a definitive diagnosis in both cases. They are the first reports of intestinal coccidia infections in AIDS patients described in Mozambique.

Association between asymptomatic carriage and sporadic (endemic) meningococcal disease in an open community.

We analysed a strain collection representative of the overall Neisseria meningitidis population circulating in an open community (46,000 inhabitants, Spain) during an endemic period (30 isolates from patients and 191 from throat cultures of healthy individuals) by both phenotypic and molecular techniques. Almost all patient isolates were assigned to three hyper-virulent lineages (ET-5 complex, ET-37 complex and cluster A4) by both multilocus enzyme electrophoresis (MEE) and pulsed-field gel electrophoresis (PFGE). In contrast, MEE and PFGE assigned 20% and 15% respectively of carrier isolates to the hyper-virulent clones (4% for both methods together). There was also a higher correlation between PFGE and phenotypes associated with virulent clones. These notable differences between the two molecular methods were further observed in more than half the carrier isolates, suggesting that the associations between these strains were distorted by recombination events. However, almost one-third of total endemic strains from symptom-free carriers and almost all patient strains belonged to clones defined by MEE and PFGE, with no known epidemiological connection. These data indicate low transmission and a weak clonal structure for N. meningitidis.