Virulent strains of Salmonella enteritidis disrupt the epithelial barrier of Caco-2 and HEp-2 cells.

To confirm the existence in nature of Salmonella enteritidis strains of different degrees of virulence and to elucidate the mechanisms underlying the effects of such strains on the epithelial barrier function, the consequences of infection of Caco-2 cells and HEp-2 cells with 15 S. enteritidis strains in a chicken infection model were examined. The more virulent strains of S. enteritidis, which are biofilm producers in adherence test medium, were able to disrupt HEp-2 and Caco-2 monolayers, as shown by transmonolayer electrical resistance and lactate dehydrogenase activity. In contrast, the low-virulence strains of S. enteritidis, which do not produce biofilms in adherence test medium, had no effect on the same cells. An avirulent rough mutant of Salmonella minnesota exhibited a pattern of behaviour similar to that of the low virulence strains of S. enteritidis, whilst a clinical Salmonella typhi strain caused rapid injury to the monolayers. The effect of supernatants of Salmonella cultures in adherence test medium on the integrity of Caco-2 cell monolayers indicated that the high-virulence S. enteritidis strains, but not the low-virulence strains, release a soluble factor when incubated under optimum biofilm-forming conditions, which enables the disruption of the integrity of Caco-2 monolayers.

Enzyme-linked immunosorbent assay with a Salmonella enteritidis antigen for differentiating infected from vaccinated poultry.

The specificity and sensitivity of indirect ELISA, based on the use of four different antigenic extracts obtained from a clinical isolate of Salmonella enteritidis, were compared with those obtained with the gm-flagellin based ELISA (IDEXX). A total of 116 serum samples from salmonellae free, naturally infected and vaccinated hens were studied. The results showed that the indirect ELISA, based on lipopolysaccharide (LPS), O-polysaccharide (PS) or membrane sediment (SD) antigens, enable the identification of a greater number of infected birds and discriminated field antibody responses from vaccinal ones better than the commercial IDEXX test. The indirect ELISA that used a O-polysaccharide rich fraction (PS) proved to be the most specific and sensitive test, suggesting that this indirect ELISA could be used to confirm IDEXX results, especially when the differentiation between vaccinated and infected poultry is required.

The relationship between glycogen synthesis, biofilm formation and virulence in salmonella enteritidis.

Salmonella enteritidis accumulated large quantities of intracellular polysaccharide when grown in unrestricted nutrient conditions. Dense, abundant cytoplasmic granules were observed by electron microscopy in sections stained by the periodic acid-chlorite technique, indicating that the polysaccharide was of the glycogen type. When biofilm-producing S. enteritidis was pre-incubated in media containing increasing levels of glucose concentration, the levels of both cytoplasmic glycogen and biofilm rose correlatively to a point where a ceiling effect was observed. Studies carried out with activators and inhibitors of glycogen biosynthesis confirmed that biofilm was formed from glycogen cell stores. On the other hand, the virulence of the biofilm-producing strain in infected chickens increased proportionally to the amount of stored glycogen, suggesting a possible role of the glycogen depot in the virulence of S. enteritidis.

Albendazole plus praziquantel versus albendazole alone as a pre-operative treatment in intra-abdominal hydatisosis caused by Echinococcus granulosus.

OBJECTIVE: To compare the effects of a combined medication of albendazole (10 mg/kg/day) plus praziquantel (25 mg/kg/day) to those of albendazole alone at different doses (10 and 20 mg/kg/day). METHOD: The protoscoleces' viability was studied in a consecutive series of patients affected by intra-abdominal hydatidosis caused by Echinococcus granulosus. In all cases the drugs were given during the month prior to surgery. RESULTS: A significant increase of patients with nonviable protoscoleces was observed in the group treated with the scolicides combination compared to those treated with albendazole alone, both at a dose of 10 mg/kg/day (P = 0.004) and at a dose of 20 mg/kg/day (P = 0.03). Albendazole sulphoxide levels in serum and in cyst fluid were higher in patients given the combined therapy than in those who received only albendazole (10 mg/kg/day: P = 0.016; 20 mg/kg/day: P = 0.034). Levels in the cysts were not significantly different probably due to the sample size; nevertheless a lineal relation between the values obtained in serum and inside the cysts could be discerned in the patients treated with the combined medication. CONCLUSION: Albendazole plus praziquantel is more effective than monotherapy with albendazole in the preoperative treatment of intra-abdominal hydatidosis.

Discrimination of strains of Salmonella enteritidis with differing levels of virulence by an in vitro glass adherence test.

The objective of this study was the in vitro differentiation of isolates of Salmonella enteritidis whose virulences differed in a chick model. A total of 14 strains of S. enteritidis were isolated from either the environment, dairy products, or infected patients. The isolates could be divided into two groups on the basis of their virulence (50% lethal dose) in chickens infected intraperitoneally. When the strains were incubated in adherence test medium (Spanish patent 9700408), only the virulent strains produced aggregates and formed visible filaments attached to the glass tube. These results suggest, although for a limited number of strains, that aggregation in such a medium could be used as a diagnostic tool to discriminate virulent strains of S. enteritidis.

[Leishmaniasis in Navarra: review of activities]. / Leishmaniasis en Navarra: revisión de actuaciones.

It has been recently reported a new case of human leishmaniasis in Navarra. Therefore, in this paper we have reviewed in a systematic and aggregated manner the data relating to this disease that is available in the Institute of Public Health of Navarra and that concerns different activities from 1976 to 1996, the date of notification at the Centre of the first case in humans. It includes the data about the known cases, since they were reported to the Epidemiological Surveillance System, together with that obtained by active searching (a figure that is three times higher). This review also includes the actions relating to the localisation of the transmitter vector, detected in different population centres of Navarra, as well as the degree of seroprevalence in the canine population on the census of the Foral Community. The figures make it possible to conclude that this illness is not sufficiently well-known in our area and that there is an underestimation in reporting to the Epidemiological Vigilance System. It possibly shows a growing incidence, which would call for profound reflection and the development of a program for controlling the disease, with activities directed basically against the reservoir and the transmitter vector

Vibrio navarrensis sp. nov., a species from sewage.

A group of 11 strains, mostly isolated from sewage water in the Province of Navarra, Spain, were found to constitute a DNA relatedness group which is 2 to 39% related to 23 species of the genus Vibrio and 2 to 3% related to two Aeromonas species. Phenotypically, these strains have all of the properties that define the genus Vibrio. However, they differ from the previously described species by three or more properties. The strains are negative for arginine, ornithine, and lysine decarboxylase activities and the Voges-Proskauer test and are unable to utilize putrescine, gluconate, glucuronate, and histidine. They utilize and produce acid from sucrose and grow at 40 degrees C. All strains grow in the presence of 0.5% (wt/vol) NaCl, and seven strains grow weakly in peptone water lacking NaCl. The group of strains which we studied can also be differentiated from other Vibrio species by fatty acid content. The G+C ratio of the DNA is 45 to 47 mol%. The name Vibrio navarrensis sp. nov. is proposed for these strains; strain 1397-6 (= CIP 103381) is the type strain.

[Extraintestinal isolation of Salmonella in chickens: epidemiologic study of 3 salmonellosis outbreaks after ingestion of raw eggs]. / Aislamiento extraintestinal de Salmonella en gallinas: estudio epidemiológico de dos brotes de salmonelosis por consumo de huevo crudo.

A taxonomic analysis of the malolactic microflora present in nine grape samples from different zones of Galicia, was carried out. Nineteen strains were isolated and identified as Lactobacillus plantarum (42%), L. brevis (10.6%), L. casei (5.25%), L. hilgardii (5.25%), Streptococcus cremoris (5.25%), Leuconostoc lactis (5.25%), L. oenos (10.6%), and Pediococcus acidilactici (15.8%).