SCI scientific publications 1990
TSST-1 production by Staphylococcus aureus subsp. anaerobius
Research In Microbiology 141(9):1073-6.
La capacité de produire des entérotoxines et du TSST-1 est étudiée chez 53 souches sauvages de Staphylococcus aureus subsp. anaerobius et chez 48 mutants aerotolérants obtenus par incubation des souches sauvages en aérobiose. La protéine A est produite par 4 souches sauvages et 3 souches aérotolérantes. Le TSST-1 est produit par 2 souches sauvages aux concentrations de 7,0 et de 6,8 ng/ml, concentrations définies par ELISA. Aucune entérotoxine (A-E) n`est détectée, quel que soit l`extrait.… Leer más
Goyache J., Ruiz JA., Orden JA., Hernandez FJ., Gomez-Lucia E., de la Fuente R., Bergdoll MS. and Suarez G.
Overlay technique for direct detection and identification of haemolytic Listeria on selective plating medium. Comparison of five media
Zeitschrift Für Lebensmittel-Untersuchung Und -Forschung 191(1):16-9.
An overlay technique is proposed for the identification and counting of haemolytic Listeria colonies directly on selective plating media. The technique was applied to different Listeria-selective plating media. In pure culture studies with collection strains, the overlay technique was more efficient and reliable for detection haemolytic Listeria species compared with the incorporation of blood into the agar. The efficacy of the overlay technique for the direct detection of haemolytic colonies of Listeria from raw milk samples was related to agar selectivity. The best results were obtained with Listeria-selective agar medium modified (LSAMM). Catalase assay, together with reactions for aesculin and tellurite, were useful and reliable criteri… Leer más
Dominguez L., Fernandez-Garayzabal JF., Blanco MM., Briones V., Vazquez-Boland JA., Blanco JL. and Suarez G.
Influence of temperature of incubation on Staphylococcus aureus growth and enterotoxin production in homemade mayonnaise
Journal Of Food Protection 53(5):386-390.
Homemade mayonnaise, in which pH had been adjusted to a range between 5.0 and 5.8 by the addition of vinegar, was inoculated with 8 S. aureus strs known to be enterotoxigenic. They were incubated for a max. of 7 d at 22, 28, 37 and 44°C. Periodically, staphylococcal growth and pH were determined. Mayonnaise samples were examined on d 7 for the presence of enterotoxins A, B, C and D. Staphylococcal growth was higher at 22° (av. log10 7.21 cfu/g), than at the other temp. tested (log10 7.15, 6.77, and 5.93 cfu/g, respectively for 28, 37 and 44°), suggesting a better growth in mayonnaise at low room temp. Enterotoxin synthesis took place mainly at 28°, as 33.3% of the total enterotoxins produced were detected at this temp. However, some strs sy… Leer más
Gomez-Lucia E., Goyache J., Orden JA., Domenech A., Hernandez FJ., Ruiz JA. and Suarez G.
Enterotoxin production by staphylococci isolated from healthy goats
Applied And Environmental Microbiology 56(5):1323-6.
The ability of 342 staphylococcal isolates from different anatomical sites in healthy goats to produce staphylococcal enterotoxins (SE) was investigated. SE were produced by 74.3% of the 70 coagulase-positive strains and by 22% of the coagulase-negative strains studied. Most enterotoxigenic strains were isolated from the skin of udders and teats and from milk. SEC was the SE type most frequently produced, either alone (67.9%) or in combination with others. Five coagulase-negative species not previously reported as SE producers were identified (Staphylococcus chromogenes, S. warneri, S. sciuri, S. saprophyticus, and S. lentus). SEA, SEB, and SEC were detected in the milk of 17 of the 133 healthy goats studied. These results suggest that the … Leer más
Valle J., Gomez-Lucia E., Piriz S., Goyache J., Orden JA. and Vadillo S.
Revision of the antigenic structure of genus Listeria
FEMS Microbiology Letters 55(1-2):113-9.
O-antigenic structure of genus Listeria was studied, using antisera (obtained from rabbits) against different O-antigens of reference strains of each serovar. The titres of sera were determined by agglutination using antigens of the same reference strains as well. Some differences from the actual scheme were found: serum antifactor-IX gave a lower titre than expected against antigens 4ab and 6b, while the titre observed against antigen 4b was higher than the expected in this case. Serum antifactor-VIII presented a higher titre than could be expected against antigen 6b. The strains of serovars 4d and 4e used in this experience were impossible to distinguish, and could have been classified in the same serovar. We could not obtain serum antifa… Leer más
Garcia JA., Dominguez L., Briones V., Blanco MM., Fernandez-Garayzabal JF. and Suarez G.
Revision of the O antigenic scheme of Listeria
Acta Microbiologica Hungarica 37(1):87-91.
Factor sera against Listeria O antigens (serologic reference strains) were produced. The results confirm the validity of the O antigenic scheme established for Listeria, but show slight discrepancies in strains of serovars 4b, 4ab and 6b… Leer más
Garcia JA., Dominguez L., Briones V., Fernandez-Garayzabal JF., Vazquez-Boland JA. and Suarez G.
O antigenic structure of Listeria grayi and Listeria murrayi
Acta Microbiologica Hungarica 37(1):93-6.
Cross-agglutination and absorption studies indicated that two serological reference strains of Listeria grayi and Listeria murrayi differed in at least one O factor. The serological analysis revealed that the unshared O factors are not present in other Listeria serovars. These results are not in accordance with the antigenic structure previously reported for L. grayi and L. murrayi, then a new O antigen formulation is proposed for these species: L. grayi (III), XII, XIV and XVI; L. murrayi (III), XII, XIV and XVII… Leer más
Vazquez-Boland JA., Dominguez L., Fernandez-Garayzabal JF., Briones V., Garcia JA. and Suarez G.
Revision of the validity of CAMP tests for Listeria identification. Proposal of an alternative method for the determination of hemolytic-activity by Listeria strains
Acta Microbiologica Hungarica 37(2):201-6.
The validity of CAMP tests with Staphylococcus aureus and Rhodococcus (Corynebacterium) equi as defined for Listeria identification was revised. This characterization method appeared to be unreliable for two reasons: first, a positive CAMP test with R. equi is not specific for Listeria ivanovii as Listeria monocytogenes (and Listeria seeligeri) give also a clear positive reaction; second, doubtful reactions could be observed with S. aureus when assaying haemolytic and non-haemolytic Listeria strains (possibility of false negative and false positive results; subjectivity of the interpretation). The use of a Microplate technique previously described instead of CAMP tests is proposed for the reliable demonstration of the haemolytic character o… Leer más
Vazquez-Boland JA., Dominguez L., Fernandez-Garayzabal JF., Rodriguez-Ferri E., Briones V., Blanco MM. and Suarez G.
