Sonia Regina T. Silva Ramos

Phenotypic and Genotypic Characteristics of Escherichia coli Strains of Non–Enteropathogenic E. coli (EPEC) Serogroups that Carry eae and Lack the EPEC Adherence Factor and Shiga Toxin DNA Probe Sequences

This study was conducted to characterize the virulence potential of 59 Escherichia coli strains carrying EAE and lacking the enteropathogenic E. coli adherence factor and Shiga toxin probe sequences. In hybridization studies, all strains carried the locus of enterocyte effacement (LEE)-associated DNA sequences. Of the other 15 virulence DNA sequences tested, HLY was the most frequent (44.1%); 17 combinations of these sequences were found, but strains carrying EAE only (EAE profile) were the most frequent (35.6%). Except for 1 cytodetaching strain, all others adhered to HeLa and Caco-2 cells, most of which (approximately 75.0%) showed variations of the localized adherence pattern. Actin accumulation was detected in 75.9% of the nondetaching strains. Most strains had LEE, probably inserted in pheU (49.2%), and presented a nontypeable intimin (83.1%). Translocated intimin receptor-derived DNA sequences correlated with enteropathogenic and enterohemorrhagic E. coli in 61.0% and 32.0% of the strains, respectively. Thirty-five different serotypes were found. Only strains with the EAE profile were associated with diarrhea (P=.039).

Etiology of childhood diarrhea in the northeast of Brazil: significant emergent diarrheal pathogens

In a study conducted in João Pessoa, northeast of Brazil, 2344 Escherichia coli isolated from 290 infants with diarrhea and 290 healthy matched controls were analyzed for virulence traits. Enteroaggregative E. coli (EAEC) was the most prevalent pathogen associated to acute diarrhea. Based on the results of colony blot hybridization, serotyping, and HEp-2 cell adherence assays, strains were separated in categories as typical enteropathogenic E. coli (EPEC) (1.7%), atypical EPEC (a-EPEC) (9.3%), EAEC (25%), enterotoxigenic E. coli (10%), and enteroinvasive E. coli (EIEC) (1.4%). No enterohemorrhagic E. coli strains were isolated. Other enteropathogens were found, including Salmonella (7.9%), Shigella spp. (4.1%), thermophilic Campylobacter spp. (2.4%), Giardia lamblia (9.3%), and Entamoeba histolytica (5.8%). All enteropathogens were associated with diarrhea (P < 0.01). However, the association was lower for EPEC and EIEC (P < 0.03). Different pathogens associated with diarrhea may have been changing in Brazil where EAEC and a-EPEC seem to be the most prevalent pathogens among them.

Prevalence of colonization factor antigens (CFAs) and adherence to HeLa cells in enterotoxigenic Escherichia coli isolated from feces of children in São Paulo.

Fifty‐eight enterotoxigenic Escherichia coli (ETEC) strains, isolated from children with and without diarrhea in Sao Paulo, were examined for the presence of colonization factor antigens (CFAs) and their ability to adhere to HeLa cells. Antisera to CFA/I, the coli surface (CS) antigens CS1CS3, CS2CS3, and CS2 of CFA/II, CFA/III, and CS5CS6 and CS6 of CFA/IV were used. CFAs were identified in 43% of the ETEC strains: 40% of the strains with CFAs harbored CFA/I, 24% carried CFA/II (CS1CS3), 24% carried CFA/IV (CS6), and 12% carried CFA/IV (CS5CS6). CFAs occurred mainly among ETEC strains producing only heat‐stable (ST‐I) enterotoxin and in strains also producing heat‐labile toxin (LT‐I). No ETEC strains tested expressed CFA/III. A marked change in serotypes of ST‐I‐producing strains was found in Sao Paulo between 1979 and 1990. Adherence to HeLa cells was detected in 14% of the ETEC strains. All of them had a diffuse adherence pattern and produced only ST‐I, and 88% carried CS6 antigen.

Infecção hospitalar em Unidade de Terapia Intensiva Neonatal: há influência do local de nascimento?

ABSTRACT Objective: To analyze the hospital infection incidence rate and their etiologic profile among inborn and outborn infants admitted to a Neonatal Intensive Care Unit (NICU). Methods: This cohort study included newborns admitted to a NICU in 2002 and 2003. Hospital infection epidemio-logic surveillance was conducted prospectively following the National Nosocomial Infections Surveillance System methodology. Clinical and demographic aspects, early and late hospital infection incidence rates, and the organisms isolated from newborns with late hospital infection were compared according to birth place. Results: In this study, 426 (88%) inborn and 60 (12%) outborn infants were included. Early and late onset hospital infection incidence rate were 10% and 21% respectively, with no statistical difference between inborn and outborn infants for early ( p =0.40) and late hospital infections ( p =0.41). Among the microorganisms isolated in late hospital infections, 52% were Gram-positive organisms: coagulase-negative

Use of selective medium for Burkholderia cepacia isolation in respiratory samples from cystic fibrosis patients

Burkholderia cepacia colonizes cystic fibrosis (CF) patients. We evaluated the impact of the use of a selective medium in the rate of B. cepacia recovery from respiratory samples of CF patients. During a 6-month period, respiratory samples were collected from 106 CF patients and cultivated on selective media including a B. cepacia selective medium. Confirmation of the identity of B. cepacia isolates was carried out by species specific PCR and determination of genomovar status performed by a sequential PCR approach. Results of B. cepacia isolation during this period were compared to the preceding two years, when the sample processing was identical except for the lack of the B. cepacia selective medium. B. cepacia was isolated in 11/257 (4.2%) of the samples using the selective medium, in contrast with the preceding two years, when it was isolated in 6/1029 samples (0.58%), p < 0.0001. Identity of all 11 isolates was confirmed by PCR and genomovar determination was accomplished in all but one isolate. These results suggest that the use of a selective medium increases recovery rate of B. cepacia from respiratory samples.

Meningite bacteriana no período neonatal evolução clínica e complicações em 109 casos: clinical evolution and complications in 109 cases

Bacterial meningitis has special clinical features in the newborn infant. Major complications and sequelae result from the infectious involvement of the CNS in the majority of these children. We studied 109 newborn infants with bacterial meningitis accompanied from January 1977 to April 1987. The mortality rate was 34.8%. Perinatal risk factors were not found. The majority (80.5%) were term newborn infants. The main signs at admission were convulsion (53.2%), bulging fontanel (37.6%) and apnea (20.2%), and the main symptoms were neurosensorial depression (64.2%), nursing refuse (64.2%), fever (50.5%) and irritability (35.8%). Complications during hospitalization were ventriculitis (34.9%), inappropriate antidiuretic hormone secretion syndrome (27.5%), subdural collection (8.3%), brain abscess (4.6%) and brain infarction (2.8%). Inappropriate antidiuretic hormone secretion syndrome and ventriculitis were closely associated with high mortality. Seventy one children survived: 44 (62%) had gross abnormalities at the neurologic examination, and 29 (40.8%) developed hydrocephalus. Neurological follow-up of these children is important. Prognostic can change along the course of long time follow-up.Bacterial meningitis, has special clinical features in the newborn infant. Major complications and sequelae result from the infectious involvement of the CNS in the majority of these children. We studied 109 newborn infants with bacterial meningitis accompanied from January 1977 to April 1987. The mortality rate was 34.8%. Perinatal risk factors were not found. The majority (80.5%) were term newborn infants. The main signs tat admission were convulsion (53.2%), bulging fontanel (37.6%) and apnea (20.2%), and the main symptoms were neurosensorial depression (64.2%), nursing refuse (64.2%), fever (50.5%) and irritability (35.8%). Complications during hospitalization were ventriculitis (34.9%), inappropriate antidiuretic hormone secretion syndrome (27.5%), subdural collection (8.3%), brain (abscess (4.6%) and brain infarction (2.8%). Inappropriate antidiuretic hormone secretion syndrome and ventriculitis were closely associated with high mortality. Seventy one children survived: 44 (62%) had gross abnormalities at the neurologic examination, and 29 (40.8%) developed hydrocephalus. Neurological follow-up of these children is important. Prognostics can change along the cours of long time follow-up.Bacterial meningitis, has special clinical features in the newborn infant. Major complications and sequelae result from the infectious involvement of the CNS in the majority of these children. We studied 109 newborn infants with bacterial meningitis accompanied from January 1977 to April 1987. The mortality rate was 34.8%. Perinatal risk factors were not found. The majority (80.5%) were term newborn infants. The main signs tat admission were convulsion (53.2%), bulging fontanel (37.6%) and apnea (20.2%), and the main symptoms were neurosensorial depression (64.2%), nursing refuse (64.2%), fever (50.5%) and irritability (35.8%). Complications during hospitalization were ventriculitis (34.9%), inappropriate antidiuretic hormone secretion syndrome (27.5%), subdural collection (8.3%), brain (abscess (4.6%) and brain infarction (2.8%). Inappropriate antidiuretic hormone secretion syndrome and ventriculitis were closely associated with high mortality. Seventy one children survived: 44 (62%) had gross abnormalities at the neurologic examination, and 29 (40.8%) developed hydrocephalus. Neurological follow-up of these children is important. Prognostics can change along the cours of long time follow-up.

Tuberculose do sistema nervoso central em crianças: 1. Apresentaçäo clínica e laboratorial

Tuberculosis still occupies a remarkable place as a worldwide health problem, chiefly in emerging countries, like Brazil. The central nervous system (CNS) involvement by Mycobacterium tuberculosis is one of the most feared features of disease, because of its high morbidity and mortality. This study aimed to describe some epidemiological, clinical and laboratorial aspects of 52 children in a tertiary pediatric hospital with CNS tuberculosis. At diagnosis, the majority of patients showed low age, compromised nutritional status, previous contact with bacillary individuals, delayed or absent immunization, advanced neurological signs and compatible abnormalities in cerebrospinal fluid (CSF) analysis and in radiological findings. The etiologic agent was identified by staining methods or CSF and other fluids culturing in 40% of patients. In most cases, despite of suggestive clinical, epidemiological and laboratorial picture and feasibility of patients access to health care centres, therapy was started lately.

Tuberculose do sistema nervoso central em crianças: 2. Tratamento e evoluçäo

Neurologic damage is usual after central nervous system (CSN) tuberculosis recovery. Treatment is long, difficult and prone to complications. Many factors are enrolled as prognostic determinants. This study aimed to describe the treatment and outcome of 52 children with CNS tuberculosis of a tertiary pediatric hospital. All of them received standard triple drug regimen, and 41 (78.8%) received corticosteroids as adjunctive therapy. Hydrocephalus was common (28 of 41 tested), but only 8 (15.4%) patients underwent ventricular shunt surgery. Hepatotoxicity to anti tuberculosis drugs occurred in 32 (61.5%) cases, but in only 3 (9.4%) drug substitution was necessary. There were 8 (15.4%) deaths and 24 (46.1%) cases developed neurologic damage after therapy. Patients who did not receive steroids during treatment and those with advanced neurological involvement at diagnosis showed a tendency to worse prognosis.

Accuracy of the QuantiFERON-TB Gold in Tube for diagnosing tuberculosis in a young pediatric population previously vaccinated with Bacille Calmette-Guérin

Objective: To evaluate the accuracy of an interferongamma release assay (QuantiFERON-TB Gold in Tube) for diagnosing Mycobacterium tuberculosis infection in a young pediatric population. Methods: 195 children previously vaccinated with BCG were evaluated, being 184 healthy individuals with no clinical or epidemiological evidence of mycobacterial infection, and 11 with Mycobacterium tuberculosis infection, according to clinical, radiological, and laboratory parameters. A blood sample was obtained from each child and processed according to the manufacturers instructions. The assay performance was evaluated by a Receiver Operating Characteristic (ROC) curve. Results: In the group of 184 non-infected children, 130 (70.6%) were under the age of four years (mean age of 35 months). In this group, 177 children (96.2%) had negative test results, six (3.2%) had indeterminate results, and one (0.5%) had a positive result. In the group of 11 infected children, the mean age was 58.5 months, and two of them (18%) had negative results. The ROC curve had an area under the curve of 0.88 (95%CI 0.82-0.92; p<0.001), disclosing a predictive positive value of 81.8% for the test (95%CI 46.3-97.4). The assay sensitivity was 81.8% (95%CI 48.2-97.2) and the specificity was 98.8% (95%CI 96-99.8). Conclusions: In the present study, the QuantiFERON-TB Gold in Tube performance for diagnosing M. tuberculosis infection was appropriate in a young pediatric population.

Acurácia do QuantiFERON-TB Gold in Tube no diagnóstico de tuberculose em uma população pediátrica jovem previamente vacinada com Bacille Calmette-Guérin

Objective: To evaluate the accuracy of an interferongamma release assay (QuantiFERON-TB Gold in Tube) for diagnosing Mycobacterium tuberculosis infection in a young pediatric population. Methods: 195 children previously vaccinated with BCG were evaluated, being 184 healthy individuals with no clinical or epidemiological evidence of mycobacterial infection, and 11 with Mycobacterium tuberculosis infection, according to clinical, radiological, and laboratory parameters. A blood sample was obtained from each child and processed according to the manufacturers instructions. The assay performance was evaluated by a Receiver Operating Characteristic (ROC) curve. Results: In the group of 184 non-infected children, 130 (70.6%) were under the age of four years (mean age of 35 months). In this group, 177 children (96.2%) had negative test results, six (3.2%) had indeterminate results, and one (0.5%) had a positive result. In the group of 11 infected children, the mean age was 58.5 months, and two of them (18%) had negative results. The ROC curve had an area under the curve of 0.88 (95%CI 0.82-0.92; p<0.001), disclosing a predictive positive value of 81.8% for the test (95%CI 46.3-97.4). The assay sensitivity was 81.8% (95%CI 48.2-97.2) and the specificity was 98.8% (95%CI 96-99.8). Conclusions: In the present study, the QuantiFERON-TB Gold in Tube performance for diagnosing M. tuberculosis infection was appropriate in a young pediatric population.