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The serotype distribution of Streptococcus pneumoniae varies through time. The introduction of pneumococcal conjugate vaccines showed a decreased prevalence of pneumococcal invasive isolates belonging to serotype 14 and an increase of serotypes not therein included. In 1993, the Hospital de Niños of Santa Fe began surveillance of the serotype distribution of invasive S. pneumoniae disease. In the period 2003-2005, 76 isolates were analysed by studying the correlation between serotype and pathology, age and MIC of penicillin. Serotype 14 was the most frequent followed by serotypes 1, 6B, 18C, 7F, 19 F and 5. Serotype 14 showed a statistically significant correlation with MICs of penicillin ranging from 0,5 to 2 mg/l. Although this serotype was more frequently observed in pneumonia than in meningitis, there was not a significant association with any particular pathology. Serotypes 14 and 1, were prevalent among children under and over 2 years old, respectively. Most of these isolates with MICs of penicillin = 2 mg/l, were from patients with pneumonia and not with meningitis. The serotype distribution was similar to that during the period 1993-99, with the exception of serotypes 18C, 4, 12F and 22F which had never been found before. The emergence of these serotypes makes it essential to continue surveillance to determine which conjugated vaccine formulation would be suitable to prevent the most frequent pneumococcal invasive infections.

The aim of the present work was to evaluate the usefulness of a simplified method for DNA extraction coupled to a nested-PCR protocol, based on the amplification of pneumolysin gene fragments for the diagnosis of pneumococcal pneumonia in pediatric patients with clinical and radiological evidence of bacterial infection. Bacterial DNA was extracted from sera by boiling and used without further purification in the PCR for the pneumolysin gene. None toxic reagents were used and the necessary steps to obtain the DNA were left at a minimum; furthermore, it overcomes the use of expensive commercial kits for DNA purification. The total procedure can be completed the same day of sampling and, most important, it avoids the use of sophisticated technology. Both in vitro analytical specificity and sensitivity (10 CFU/ml) of the assay were similar to those previously reported. When clinical samples were tested, the rate of positivity was shown to be 83.3% and 71% in pediatric patients with positive (group a) and negative blood cultures (group b), respectively. In group a, DNA detection was successful in samples from children without treatment or with less than 48 h of antibiotic therapy. None amplification was obtained from sera patients with viral infection or in samples from healthy controls. The application of the strategy described in this paper substantially seems to improve the diagnostic process in a determinate group: blood culture-negative children with pneumonia.

A case of a healthy girl with a trauma in her right leg is described. Twelve hours later she developed fever and pain in the inguinal region. Two days later, she was admitted to the Hospital, and there, an aspiration of pus from the lymph node was performed, and this sample was sent for culture. The Gram smear showed gram-positive filamentous bacilli and when Kinyoun was used they were observed as weakly acid fast rods. After four days of incubation under aerobic conditions, white and hemolitic colonies were seen on human blood agar plates. Biochemical tests as urea hydrolysis and gelatin liquefaction were performed. To complete the identification it was sent to a reference laboratory, INEI-ANLIS Dr. Carlos G. Malbrán, where the isolate was confirmed as Nocardia asteroides sensu stricto. The patient was treated with intravenous cephalotin with good evolution. Therapy was followed with oral trimethoprim-sulfamethoxazole. This case is the first report of a Nocardia infection in the Hospital de Niños de Santa Fe. The fact that N. asteroides was isolated from an immunologically competent girl should be highlighted. This species is uncommon in children and it is rare in our region. In addition, N. asteroides infections are usually seen in pulmonary disease and rarely producing cutaneous infections.

The present research was designed to investigate the concept of familiarity and how different kinds of familiarity could affect the coding and memory of places having specific and strong functional significance, i.e., sport courts. Tennis and basketball were selected. Users and nonusers of such sport courts had first to describe a sport court taking the necessary information from their stored schematic knowledge and then to describe a sport court previously seen in a photograph. Subjects' verbal reports showed a certain superiority of users' performance, a commonly found place effect, and the presence of errors only on the second task and mainly by the users group. The results are discussed in terms of the environmental schemata theory and of the different kinds of familiarity considered.

Recall and recognition of various aspects of three places were studied under incidental and intentional conditions. Data showed that subjects passing through a place incidentally remembered structural features such as walls better than variable features such as furniture. On the other hand, subjects passing through a place knowing they will be tested for memory of its remembered the variable elements better than the structural elements. The results are interpreted in terms of intentionally governed coding.