Javier Rodríguez-Granger

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.

Specimen Storage in Transport Medium and Detection of Group B Streptococci by Culture

ABSTRACT Recovery of group B streptococci (GBS) was assessed in 1,204 vaginorectal swabs stored in Amies transport medium at 4 or 21°C for 1 to 4 days either by direct inoculation onto Granada agar (GA) or by culture in blood agar (BA) and GA after a selective broth enrichment (SBE) step. Following storage at 4°C, GBS detection in GA was not affected after 72 h by either direct inoculation or SBE; however, GBS were not detected after SBE in the BA subculture in some samples after 48 h of storage and in GA after 96 h. After storage at 21°C, loss of GBS-positive results was significant after 48 h by direct inoculation in GA and after 96 h by SBE and BA subculture; some GBS-positive samples were not detected after 24 h of storage followed by SBE and BA subculture or after 48 h of storage followed by SBE and GA subculture. Storage of swabs in transport medium, even at 4°C, produced after 24 h an underestimation of the intensity of GBS colonization in most specimens. These data indicate that viability of GBS is not fully preserved by storage of vaginorectal swabs in Amies transport medium, mainly if they are not stored under refrigeration.

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.

Activity of melatonin against Leishmania infantum promastigotes by mitochondrial dependent pathway.

Visceral leishmaniasis, a potentially fatal disease, remains a major international health problem. Only a limited number of effective antileishmanial agents are available for chemotherapy, and many of them are expensive with severe side effects or have a markedly reduced effectiveness due to the development of drug resistance. Hence, there is a genuine need to develop a novel effective and less toxic antileishmanial drug. Melatonin, a neurohormone found in animals, plants, and microbes, can participate in various biological and physiological functions. Several in vitro or in vivo studies have reported the inhibitory effect of melatonin against many parasites via various mechanisms, including modulation of intracellular concentrations of calcium in the parasite and/or any other suggested mechanism. Importantly, many of available antileishmanial drugs have been reported to exert their effects by disrupting calcium homeostasis in the parasite. The objective of the present study was to test the efficacy of exogenous melatonin against Leishmania infantum promastigotes in vitro. Interestingly, melatonin not only demonstrated a significant antileishmanial activity of against promastigote viability in tested cultures but was also accompanied by an alteration of the calcium homeostasis of parasite mitochondrion, represented by earlier mitochondrial permeability transition pore opening, and by changes in some mitochondrial parameters are critical to parasite survival. These pioneering findings suggest that melatonin may be a candidate for the development of novel effective antileishmanial agents either alone or in associations with other drugs.

Diagnóstico de infección congénita

In general, congenital diagnosis is based on: a) maternal serologic assays; b) microbiologic study of amniotic fluid or fetal blood sampling; and c) serology in children and microorganism detection by polymerase chain reaction (PCR) or culture. Congenital infections due to cytomegalovirus, herpes simplex, varicella, B19 erythrovirus and toxoplasmosis are usually the result of primary infection in the mother. Therefore, when IgG antibodies are detected before pregnancy, these infections are ruled out. Definitive serologic diagnosis of acute infection in pregnant women requires the demonstration of seroconversion (i.e., from seronegative to seropositive). In these cases, amniotic fluid or fetal blood sampling should be performed to determine the presence of intrauterine congenital infection. Cytomegalovirus, rubella and toxoplasmosis can be diagnosed by detection of specific IgM antibodies in fetal blood. However, PCR in amniotic fluid has replaced conventional prenatal diagnostic techniques, including fetal blood sampling, in the diagnosis of these infections. In the newborn, these infections may be confirmed by measuring IgM specific antibodies. B19 erythrovirus can be detected by PCR in amniotic fluid or fetal blood. Congenital varicella-zoster infection may be diagnosed on the basis of persistence of IgG antibodies after birth. Definitive diagnosis of herpes simplex virus infection requires viral isolation. Swabs or scraping from clinical specimens can be inoculated into susceptible cell lines for isolation.

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.

Evaluation of the Speed-oligo Direct Mycobacterium tuberculosis Assay for Molecular Detection of Mycobacteria in Clinical Respiratory Specimens

ABSTRACT We present the first evaluation of a novel molecular assay, the Speed-oligo Direct Mycobacterium tuberculosis (SO-DMT) assay, which is based on PCR combined with a dipstick for the detection of mycobacteria and the specific identification of M. tuberculosis complex (MTC) in respiratory specimens. A blind evaluation was carried out in two stages: first, under experimental conditions on convenience samples comprising 20 negative specimens, 44 smear- and culture-positive respiratory specimens, and 11 sputa inoculated with various mycobacterium-related organisms; and second, in the routine workflow of 566 fresh respiratory specimens (4.9% acid-fast bacillus [AFB] smear positives, 7.6% MTC positives, and 1.8% nontuberculous mycobacteria [NTM] culture positives) from two Mycobacterium laboratories. SO-DMT assay showed no reactivity in any of the mycobacterium-free specimens or in those with mycobacterium-related organisms. Compared to culture, the sensitivity in the selected smear-positive specimens was 0.91 (0.92 for MTC and 0.90 for NTM), and there was no molecular detection of NTM in a tuberculosis case or vice versa. With respect to culture and clinical data, the sensitivity, specificity, and positive and negative predictive values for the SO-DMT system in routine specimens were 0.76 (0.93 in smear positives [1.0 for MTC and 0.5 for NTM] and 0.56 in smear negatives [0.68 for MTC and 0.16 for NTM]), 0.99, 0.85 (1.00 in smear positives and 0.68 in smear negatives), and 0.97, respectively. Molecular misidentification of NTM cases occurred when testing 2 gastric aspirates from two children with clinically but not microbiologically confirmed lung tuberculosis. The SO-DMT assay appears to be a fast and easy alternative for detecting mycobacteria and differentiating MTC from NTM in smear-positive respiratory specimens.

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

Evaluation of the rapid RIDAQUICK Campylobacter® test in a general hospital

The study objective was to evaluate the effectiveness of the new rapid immunochromatographic test RIDAQUICK Campylobacter® (r-biopharm AG, Darmstadt, Germany) for the qualitative detection of Campylobacter antigens in pathologic feces from primary and specialist care patients. Three hundred feces samples were studied from patients with diarrhea, 50.6% from adults and 49.4% from children, which were received by our microbiology laboratory for coproculture. Campylobacter culture results, with or without PCR data, served as reference values for the comparative evaluation of RIDAQUICK Campylobacter® findings. Campylobacter was detected in 12.3% of samples. The diagnostic accuracy values of the RidaQuick Campylobacter® versus culture were: sensitivity of 87%, specificity of 97%, and positive and negative predictive values of 77% and 98%, respectively. RIDAQUICK Campylobacter® is a rapid test for the diagnosis of enteritis due to Campylobacter and could be an option for the clinical diagnosis of one of the main causes of bacterial enteritis in resource-limited settings.