Paulo da Silva

Etiology of acute diarrhea among children in Ribeirão Preto-SP, Brazil

To study the main enteropathogens causing diarrhea in the region of Ribeirão Preto regarding serogroups and serotypes, the feces of 1836 children under 10 years old, from both sexes, attack of acute gastroenteritis, were analysed during a period of 4 years in Adolfo Lutz Institute - Ribeirão Preto, SP. The pathogens identified by standard methods were the following: Escherichia coli, Salmonella spp., Shigella spp., Campylobacter spp., Yersinia spp., and Cryptosporidium spp. Positive samples were 22.8% (419) with 1.7% association of pathogens. Larger isolates were mainly from children 0 to 11 months old. Enteropathogenic E. coli (EPEC) was most frequent (8.7%) with predominance of serogroup O119 (40.2%), followed by Shigella (6.2%), 63.6% of which S. sonnei.

Bacterial diversity in soil in response to different plans, phosphate fertilizers and liming

Este estudo avaliou a diversidade de bacterias isoladas do solo em resposta a diferentes plantas (controle, Brachiaria ruziziensis e Cajanus cajan), fertilizantes (controle, superfosfato simples e fosfato de rocha) e calagem (com e sem calcario). As caracteristicas fenotipicas e fisiologicas dos isolados foram registradas e organizadas em um arquivo para identificar as bacterias. Entre os isolados, 95% foram de bacterias Gram positivas e 5% bacilos Gram negativos. B. ruziziensis favoreceu mais os bacilos Gram positivos nao esporulados e bacilos Gram negativos que o solo com C. cajan ou nao cultivado. O numero de bacilos Gram positivos esporulados foi superior nas parcelas fertilizadas com fosfato do que nas nao adubadas ou fertilizadas com fosfato de rocha. Nas parcelas nao fertilizadas, maior numero de cocos Gram positivos e bacilos Gram negativos foi obtido do que nas parcelas fertilizadas. A ausencia de calagem favoreceu os bacilos Gram positivos esporulados, cocos Gram positivos e os bacilos Gram negativos, enquanto que, com calagem foram encontradas proporcoes maiores de bacilos Gram positivos nao esporulados. De 7 a 86% do total de isolados utilizaram diferentes carboidratos. O registro dos dados utilizado neste experimento foi efetivo na identificacao dos isolados e pode ser util para o diagnostico das bacterias do solo. Os generos mais frequentes foram Bacillus, Cellulomonas, Rhodococcus, Enterobacter, Flavobacterium, Micrococcus e Arthrobacter. A diversidade bacteriana foi aumentada nas parcelas com calagem, nao fertilizadas e cultivadas com plantas.

Streptococcus pneumoniae and Haemophilus influenzae as etiological agents of conjunctivitis outbreaks in the region of Ribeirão Preto, SP, Brazil

In the study of conjunctivitis outbreaks occurring from September 1994 to September 1996 in the region of Ribeirão Preto, conjunctival exudates of 92 patients were cultivated in Instituto Adolfo Lutz Laboratory I, Ribeirão Preto. Most cases occurred in the age range 2-7 years. The etiological agents which were most frequently isolated from the analyzed cases were: Streptococcus pneumoniae and Haemophilus influenzae, in 40.22% and 21.74%, respectively. 51.35% of the S. pneumoniae isolated strains were not typable. The oxacillin-resistant S. pneumoniae strains were submitted to the minimum inhibitory concentration test (MIC) and three of them presented intermediate resistance, whereas only one was highly resistant to penicillin.

Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum

INTRODUCTION Rhodococcus equi is an opportunistic pathogen, causing rhodococcosis, a condition that can be confused with tuberculosis. Often, without identifying M. tuberculosis, physicians initiate empiric treatment for tuberculosis. R. equi and M. tuberculosis have different susceptibility to drugs. Identification of R. equi is based on a variety of phenotypic, chromatographic, and genotypic characteristics. OBJECTIVE This study aimed to characterize bacterial isolates from sputum samples suggestive of R. equi. METHODS The phenotypic identification included biochemical assays; thin-layer chromatography (TLC) and polymerase chain reaction (PCR) were used for genotypic identification. RESULTS Among 78 Gram-positive and partially acid-fast bacilli isolated from the sputum of tuberculosis-suspected patients, 51 were phenotypically and genotypically characterized as R. equi based on literature data. Mycolic acid analysis showed that all suspected R. equi had compounds with a retention factor (R(f)) between 0.4-0.5. Genotypic characterization indicated the presence of the choE gene 959bp fragments in 51 isolates CAMP test positive. Twenty-two CAMP test negative isolates were negative for the choE gene. Five isolates presumptively identified as R. equi, CAMP test positive, were choE gene negative, and probably belonged to other bacterial species. CONCLUSIONS The phenotypic and molecular techniques used constitute a good methodological tool to identify R. equi.

Nasopharyngeal colonization by Haemophilus influenzae in children attending day-care centers, in Ribeirão Preto, State of São Paulo, Brazil

Nasopharyngeal carriage of Haemophilus influenzae (Hi) was studied in 114 healthy children < 3 years old, attending day-care centers (DCCs) in Ribeirao Preto, State of Sao Paulo, Brazil. Biotype, serotype (by specific antisera and PCR) and antibiotic susceptibility to 14 antibiotics of each isolate were determined. Carriage rates of Hi were 72.0%. Isolates belonged to biotype II (36.5%), I (21.5%), V (18.2%) and III (16.1%). The prevalence of encapsulated Hi carriers was 3.2% for type f, 1.0% for type b, 1.0% for type d and 1.0% for type e. Resistances to trimethoprim-sulphamethoxazole and ampicillin were 46.2% and 10.7% respectively. Multidrug resistance was found in 14 (15.0%) of the isolates tested. Among the isolates, 13.9% were b-lactamase producers; there were no b-lactamase negative ampicillin resistant isolates. DCCs are niches with a high potential for the spread of microorganisms and should be continuously monitored to detect elimination or replacement of H. influenzae type b colonization.

ON AN ACUTE CASE OF CHAGAS DISEASE IN A REGION UNDER VECTOR CONTROL IN THE STATE OF SÃO PAULO, BRAZIL

No vector transmitted cases of Chagas disease had been notified in the state of São Paulo since the 1970s. However, in March, 2006, the death of a six-year-old boy from the municipality of Itaporanga was notified to the Center for Epidemiological Survey of the São Paulo State Health Secretariat: an autochthonous case of acute Chagas disease. The postmortem histopathological examination performed in the Hospital das Clínicas of the Botucatu School of Medicine confirmed the diagnosis. Reference to hospital records, consultation with the health professionals involved in the case and interviews with members of the patients family supplied the basis for this study. We investigated parasite route of transmission, probable local reservoirs and vectors. No further human cases of acute Chagas disease were diagnosed. No locally captured vectors or reservoirs were found infected with Trypanosoma cruzi. Alternative transmission hypotheses - such as the possible ingestion of foods contaminated with vector excreta - are discussed, as well as the need to keep previously endemic regions and infested houses under close surveillance. Clinicians should give due attention to such signs as uni- or bilateral palpebral edema, cardiac failure, myocarditis, pericarditis, anasarca and atypical signs of nephrotic syndrome or nephritis and consider the diagnostic hypothesis of Chagas disease.

COMPARISON OF TWO SLIDE AGGLUTINATION SEROTYPING METHODS AND PCR-BASED CAPSULE TYPING FOR THE CHARACTERIZATION OF HAEMOPHILUS INFLUENZAE SEROTYPES

Ninety-three nasopharyngeal Haemophilus influenzae isolates were serotyped by two slide agglutination methods (SAST 1 and SAST 2) and the results compared with those obtained by capsule type-specific PCR. SAST 1 presented a low correlation with results obtained by PCR (75.2%) while SAST 2 showed a better agreement with the molecular technique results (93.5%). These findings suggest that SAST 2 could be an alternative method for adequate detection of H.influenzae type b.