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Biomedical subjects

E Hofer

Publications and source records attributed to E Hofer.

157 records · Page 9Linked to original sources
PubMedDate not supplied

Evaluation of virulence factors in environmental isolates of Vibrio species.

Strains of Vibrio parahaemolyticus, Vibrio fluvialis and Vibrio mimicus isolated from seafood and seawater were examined for characteristics related to infectivity, such as enzymatic activity and animal assays. All strains hydrolysed DNA, starch, gelatin and chitin. Variable results were obtained with the haemolysin, chondroitin, collagen, elastin and lecithin tests. Production of thermostable direct haemolysin by V. parahaemolyticus was detected in 7.1% strains derived from seafood and 2% from seawater. In the animal assays, strains of V. fluvialis showed positive results at skin PF (75%), mouse lethality (100%), but no fluid accumulation in the suckling mice model was noted. Concerning V. mimicus, results showed skin PF (100%), mouse lethality (100%) and fluid accumulation in suckling mice (66.6%).

Animals↗
PubMedDate not supplied

A Salmonella agona outbreak in a pediatric hospital in the city of Rio de Janeiro, Brazil.

Six Salmonella Agona strains from an outbreak of 15 days duration which occurred in a public hospital in Rio de Janeiro, Brazil, were analyzed. The outbreak involved six infants (mean age, 24 days; mean body weight, 1612 g), all of them with severe clinical signs and symptoms. Two of them had surgical implications, two were preterm and two had respiratory distress at birth. The Salmonella strains were resistant to nine antimicrobial agents (ampicillin, cefalotine, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline). Analysis of the plasmid pattern of the wild strains and of the transconjugants confirmed that these were identical strains.

Brazil↗
PubMedDate not supplied

Helicobacter pylori in dyspeptic children and adults: endoscopic, bacteriologic and histologic correlations.

Using different bacteriological (urease test, Gram staining and culture) and histological (Steiner staining and modified Giemsa staining) techniques, we searched for the presence of Helicobacter pylori in the gastric antrum of 200 dyspeptic Brazilian patients (106 females and 94 males aged 19 days to 81 years). The presence of bacteria was then correlated with the endoscopic and histological findings. H. pylori was present in 59.5% of the population studied. In Brazil, colonization occurs early, involving 37% of the dyspeptic population by 20 years of age. The presence of H. pylori in the gastric antrum was strongly associated with duodenal ulcer (P < 0.001) and a normal endoscopic examination did not exclude the possibility of colonization of the gastric antrum by H. pylori. The most sensitive test was the preformed urease test (89%). We conclude that more than one diagnostic method should preferably be used for the detection of H. pylori and that the presence of H. pylori is closely correlated with active chronic gastritis (P < 0.001).

Adolescent↗
PubMedDate not supplied

Diversity of Campylobacter isolates from three activated sludge systems.

Thermophilic campylobacters were isolated from three sewage plants in Rio de Janeiro, RJ, Brazil and identified. Laboratory analysis of 390 sewage samples showed the presence of 169 thermophilic strains. The results demonstrated that human and animal pathogenic biotypes could be isolated from activated sludge during the initial processing steps. The aeration tank could be considered a barrier to Campylobacter survival. C. jejuni was the prevalent species isolated (40.8%). The most common biotypes were C. jejuni biotype I (21.3%), C. coli biotype I (16%) and C. jejuni biotype II (14.8%).

Bacterial Typing Techniques↗
PubMedDate not supplied

Species and serovars of the genus Listeria isolated from different sources in Brazil from 1971 to 1997.

Using phenotype techniques, characterization was made to species and serovar of 3,112 strains of Listeria, isolated from different sources of infection such as human (247-7.9%) and animals (239-7.6%), as well as from various routes of infection, including food (2, 330-74.8%) and environmental constituents (296-9.5%), all coming from different regions of the country and collected during the period 1971-1997. The following species were recovered in the cultures analysed: L. monocytogenes (774-24.8%), L. innocua (2, 269-72.9%), L. seeligeri (37-1.1%), L. welshimeri (22-0.7%), L. grayi (9-0.2%), and L. ivanovii (1-0.03%). L. monocytogenes was represented by ten serovars, the most prevalent being 4b (352-11.3%), (1/2)a (162-5.2%), and (1/2)b (148-4.7%). The predominant serovar in L. innocua was 6a (2,093-67.2%). Considerations about laboratory methods for diagnosis and epidemiological aspects are presented on the basis of the results obtained.

Animals↗
PubMedDate not supplied

[Isolation of Vibrio cholerae O1 from aquatic environments and foods in Pernambuco State, Brazil].

Incidence of Vibrio cholerae O1 was studied in 2,585 samples from different aquatic environments and 91 from foods in Pernambuco State, northeastern Brazil, from 1992 to 1994. A total of 193 (7.21%) samples of V. cholerae were isolated with a higher prevalence of the Inaba serovar (183-94.8%) than the Ogawa serotype (10-5.1%). All isolates were classified as biotype El Tor, and resistance patterns to antibiotics showed that all strains were susceptible tetracycline. Some 70 random samples of Vibrio cholerae proved toxigenic, including all the Ogawa serovars. Incidence of V. cholerae O1 in river water and sewage (86.0%) pointed to fecal contamination as the most common source and vehicle for rapid spread of the microorganism in the aquatic environment. The vibrio was isolated in 2.1% of all food examined, which was less than expected.

Anti-Bacterial Agents↗
PubMedDate not supplied

A new real-time mapping system to detect microscopic cardiac excitation patterns.

A new fast, high-resolution measurement system has been developed to analyze the propagation of cardiac excitation on a microscopic scale. The instrument uses a microsensor array to detect microscopic excitation patterns at the cardiac surface. Ninety-six epicardial signals are recorded simultaneously with 14-bit resolution at 200-kHz samples per second per channel. The system operates like a digital oscilloscope. Preprocessing routines (offset, gain, and triggering) are executed within a sampling interval of 5 microseconds by 48 digital signal processors. Analog-to-digital (A/D) converters are provided with 12 Mb of buffer memory, allowing continuous recording of up to 64-k samples x 96 channels. The recorded dataset is transferred rapidly (8 Mb/sec) to the memory of the integrated computer system via VXIbus. Analysis and visualization of the propagating excitation are computed by custom-designed software. The performance of the system allows recording as well as visualization of the cardiac excitation spread in a beat-to-beat manner.

Analog-Digital Conversion↗
PubMedDate not supplied

[Fecal coliforms in sewage waters. I. Resistance to antibiotics, heavy metals and colicinogeny].

Qualitative bacteriological analysis was carried out in two sewage treatment plants in the city of Rio de Janeiro during the period 1984-1985. Specific points of the plants were selected for the collection of affluent and effluent samples. The study involved the isolation and the identification of 540 cultures of Escherichia coli that were analyzed for their resistance to eight antibiotics (sulfadiazine, streptomycin, tetracycline, chloramphenicol, kanamycin, ampicillin, nalidixic acid and gentamycin), and three heavy metals (copper sulphate, mercuric chloride and zinc sulphate) as well as colicinogeny. About 95% of the isolated cultures from the effluents had genetic markers while the samples originated from the affluents showed 70%.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Vibriocidal and agglutinating antibodies in the urban population in the municipality of Manacapuru/AM (1992-1993)].

A serological study was carried out involving 1,196 individuals residents in the urban area of Manacapuru--Amazonas, to evaluate the behavior of vibriocidal and agglutinating antibodies. A systematic random sampling procedure was employed to obtain the sample. A year later a 2nd sample of serum was obtained from 120 individuals selected among the participants of the survey. Vibriocidal antibodies microtitulation and seroagglutination in tubes were employed. The correspondence between the studied antibodies was determined by the correlation coefficient calculated according to the frequency of the titles detected. The analysis of the results revealed positive correlation between the antibodies (r = 1.0) and a decrease in titles in a large proportion of the positive samples one year later.

Adolescent↗