Antonio Sampedro

Modification of immune response in mice by ciprofloxacin.

Some studies have suggested that the addition of ciprofloxacin to in vitro cultures of mitogen-stimulated lymphocytes exerts inhibitory effects on cell cycle progression and immunoglobulin (Ig) secretion. We tested the effects of this drug on some immunity parameters in BALB/c mice. Mice treated intraperitoneally with ciprofloxacin (10 mg/kg of body weight per day) for 3 consecutive days and immunized with sheep erythrocytes 24 h after the last injection showed significant suppression of hemolytic IgG-forming cells, whereas the response of IgM-forming cells remained unchanged. When treatment lasted 7 days the response of antibody-forming cells was not modified. When the 3-day treatment was started at 24 h after immunization with sheep erythrocytes, the response of IgM-forming cells was increased, whereas the response of IgG-forming cells was suppressed. Delayed-type hypersensitivity to sheep erythrocytes was significantly suppressed in animals that received the 3-day treatment with ciprofloxacin and were immunized subcutaneously 24 h after the last injection. In vitro proliferation of lymphocytes from ciprofloxacin-treated mice in response to either lipopolysaccharide or concanavalin A was also suppressed. Leukopenia and an increase in the level of granulocyte-macrophage colony-forming cells in bone marrow were also observed in ciprofloxacin-treated mice. These results, together with those from other reports, suggest that modification of the biological responses by ciprofloxacin is a complex phenomenon that may be influenced by several factors.

Granadaene: Proposed Structure of the Group B Streptococcus Polyenic Pigment

ABSTRACT The goal of this work was to determine the chemical nature of the red pigment produced by Streptococcus agalactiae, which has been thought to be a carotene. We extracted the pigment with 0.1 M KOH and purified it by column chromatography on Sephadex LH. Data from elemental analysis and mass and nuclear magnetic resonance spectra lead us to propose the structure to be that of a new ornithine rhamno-polyene with 12 conjugated double bonds, to which we have assigned the trivial name granadaene.

Mediterranean spotted fever with encephalitis.

Rickettsia conorii infection is endemic in the Mediterranean basin, where it is known as Mediterranean spotted fever, also known as Boutonneuse fever and Marseilles fever. We report the case of a 66-year-old diabetic man who presented a severe form of the disease, complicated by acute renal failure, thrombocytopenia and encephalitis. Diagnosis was confirmed by indirect immunofluorescence assay. Despite appropriate treatment, severe neurological sequelae have remained. Medical literature on encephalitis caused by R. conorii is also reviewed.

Experimental Infection of Mice with Yersinia enterocolitica Serotype O9 by Oral and Parenteral Routes: Spreading and Enterotropism of Virulent Yersiniae

Abstract. An isogenic pair of Yersinia enterocolitica serotype O9 strains, with and without virulence plasmid, was used to study the plasmid role in the infection of BALB/c mice by oral, intraperitoneal, and intravenous routes. The plasmid-bearing strain, but not its plasmid-less derivative, caused enteric infection after challenge by all three routes. The virulence plasmid did not influence the peritoneal clearance of yersiniae, but only the plasmid-bearing yersiniae were able to move from the peritoneal cavity to the bloodstream, and thus they spread to spleen and liver. Moreover, plasmid-bearing yersiniae were able to move from the liver to the gallbladder, and they shed in bile into the intestine. Western blot analysis of antibody responses to chromosomally encoded outer membrane proteins revealed similar patterns with sera from mice challenged with each one of the two strains by intraperitoneal route. In contrast, only the plasmid-bearing strain elicited an antibody response to these antigens in mice challenged by oral route. Although mice experimentally infected with plasmid-bearing O9 yersiniae developed an enteric infection, irrespective of the inoculation route, differences between the first steps in infection by oral and parenteral routes may be important, especially when the infection model is used as an approach to study the yersinia-host interactions.

Pigment production by Streptococcus agalactiae in quasi-defined media

ABSTRACT A quasi-defined medium that supports the growth ofStreptococcus agalactiae as pigmented colonies has been developed. The medium contains starch, a peptic digest of albumin, amino acids, nucleosides, vitamins, and salts. The presence of free cysteine, which could be replaced with other sulphur-containing compounds and to a lesser degree by reducing agents, was required for pigment formation.

Comparative evaluation of a new chemiluminiscent assay and an ELISA for the detection of IgM against measles

The primary test for the laboratory confirmation of measles is immunoglobulin M (IgM) serology. It is therefore important to evaluate new commercial measles IgM immunoassays to ensure high‐quality measles diagnostic testing. The purpose of this study was to evaluate the diagnostic performance of LIAISON IgM measles (DiaSorin, Saluggia, Italy), a new automated chemiluminescence immunoassay (CLIA), in comparison with enzyme immunoassay (EIA) Enzygnost (Siemens, Marburg, Germany).

Suitability of Frozen Serum Stored in Gel Separator Primary Sampling Tubes for Serological Testing

ABSTRACT The suitability of frozen serum after storage in primary sampling tubes with a gel separator for serological enzyme-linked immunosorbent assay testing (hepatitis B virus surface antigen [HBs Ag], anti-HBs Ag, anti-Toxoplasma gondii immunoglobulin G [IgG], anti-rubella virus IgG, anti-cytomegalovirus IgM, and anti-Epstein-Barr virus IgM) was evaluated for 375 samples. No difference was found among test results using fresh or stored frozen serum

Utilidad del medio cromogénico MPO® en el procesamiento habitual del urocultivo

BACKGROUND: The chromogenic culture medium, MPO, was compared to culture on CLED (cystein, lactose, electrolyte-deficient) agar for the detection, enumeration and identification of urinary tract pathogens. METHODS: A total of 1,080 clinical urine specimens were assessed. All samples were inoculated in MPO and CLED using the calibrated loop method. RESULTS: Among 145 positive urine samples, 171 strains of bacteria were isolated (111 Escherichia coli, 26 Enterococcus spp., 12 Proteus spp., 10 Enterobacteriaceae from the Klebsiella-Enterobacter-Serratia group, 5 Pseudomonas aeruginosa, 4 Streptococcus agalactiae, 3 Staphylococcus spp. and 4 Candida albicans. For all samples, enumeration of microorganisms was comparable with the two media studied. Identification was also similar, except for 6 cases in which Enterococcus spp. were only detected with the chromogenic medium. CONCLUSIONS: Overall urine culture results with MPO chromogenic medium were similar to those obtained with CLED, making it a feasible alternative to the standard medium. Moreover, use of a chromogenic technique implies a significant reduction in workload, since additional tests to identify the microorganisms isolated are not needed in most cases.

Endocarditis por Streptococcus agalactiae

Streptococcus agalactiae es una etiologia poco comun de endocarditis infecciosa. Describimos las caracteristicas clinicas, tratamiento y evolucion de nuestros casos diagnosticados entre 1996-2003. Encontramos 4 pacientes con valvulas nativas afectadas y vegetaciones en todos los casos. Todos presentaron insuficiencia aortica grave, e insuficiencia cardiaca en 3 casos. El recambio valvular se efectuo en todos ellos, con una mortalidad del 50%. Las endocarditis infecciosas por S. agalactiae son muy agresivas. Para prevenir la destruccion de las valvas y serias complicaciones, debe considerarse la cirugia precoz.

Use of Unmodified Starches and Partial Removal of Serum To Improve Granada Medium Stability

ABSTRACT The use of 1% unmodified rice starch and 1% horse serum instead of 2% soluble starch and 5% serum in Granada medium is described. These components result in a medium of increased stability, preventing spoilage after a few days of storage at room temperature.