Detection of parC mutations in Streptococcus pneumoniae by Real-time PCR and Taqman–MGB probes

A Real-time PCR assay was developed by using Taqman-MGB probes to screen mutations at codons Ser79 and Asp83 of Streptococcus pneumoniae parC. One hundred and thirty levofloxacin-susceptible and forty-two levofloxacin-resistant clinical strains were assayed. Mutations at codon 79 were found among all the levofloxacin-resistant strains. Mutations at codon 79 or 83 were found in ten levofloxacin-susceptible strains. This procedure is a reliable method for a rapid detection of mutations in the QRDRs of parC gene of S. pneumoniae and could be carried out in a diagnostic laboratory for some high-risk patients or in epidemiological surveys.

Detection of Campylobacter jejuni and Campylobacter coli in chicken meat samples by real-time nucleic acid sequence-based amplification with molecular beacons

A nucleic acid sequence-based amplification (NASBA) assay based on molecular beacons was used for real-time detection of Campylobacter jejuni and Campylobacter coli in samples of chicken meat. A set of specific primers and beacon probe were designed to target the 16S rRNA of both species. The real-time NASBA protocol including the RNA isolation was valid for both of the cell suspensions in buffered saline and the artificially contaminated chicken meat samples. The presence of rRNA could be correlated with cellular viability, following inactivation of the bacteria by heating, in inoculated chicken meat samples but not in RNase-free cell suspensions.

An observational study on outgrowing food allergy during non-birch pollen-specific, subcutaneous immunotherapy

BACKGROUND

Birch pollen-specific immunotherapy (SIT) decreases allergy to foods containing birch pollen-homologous allergens. Cross-reactivity was also observed between plane tree pollen and some vegetable foods.

OBJECTIVE

The aim of this study was to evaluate the outgrowing of food allergy by patients suffering from vegetable food allergy associated with plane tree pollinosis (rhinoconjunctivitis and/or asthma) during plane tree pollen SIT.

METHODS

An observational and prospective study was conducted in 16 adult patients suffering from vegetable food allergy (hazelnut, walnut, lettuce, peach and cherry) and from plane tree pollinosis receiving plane tree pollen SIT for 1 year. Open oral challenges with the implicated food were performed before and after SIT. Blood samples were drawn for measurement of pollen- and food-specific IgE and IgG4 before and after treatment.

RESULTS

Plane tree SIT resulted in a significant decrease in food allergy, since the mean food quantity provoking objective symptoms increased from 2.19 to 13.74 g (p < 0.05), and 6 of the 11 patients tolerated the highest level (25 g) of the challenged food after plane tree SIT. Laboratory data also showed a decrease in IgE levels and an increase in IgG4 levels after immunotherapy.

CONCLUSION

SIT with plane tree pollen has a positive impact on food allergy in plane tree pollen-allergic subjects.

Estradiol and its membrane-impermeable conjugate estradiol-BSA inhibit tamoxifen-stimulated prolactin secretion in incubated rat pituitaries

In the absence of estrogen (E), the selective E receptor modulator tamoxifen (TX) has two agonist effects in the rat pituitary: induction of progesterone receptor (PR)-dependent GnRH self-priming in the gonadotrope, and stimulation of prolactin (PRL) secretion in the lactotrope. TX-induced gonadotropin (GnRH) self-priming is absent when 10(-8) M estradiol-17beta (E2) is added to the incubation medium of pituitaries from TX-treated rats. The present experiments investigated whether PR-independent PRL release into the incubation medium of pituitaries from TX-treated ovariectomized (OVX) rats was affected by E2, and the effect of different ER ligands (ICI182780, TX, estradiol-17alpha, E2 -BSA) on TX-stimulated PRL secretion. Moreover, the effect of E2 on TRH-stimulated PRL secretion in pituitaries collected from estradiol benzoate- and TX-treated OVX rats was studied. It was found that: i) incubation with E2 supressed the PRL releasing effect of injected TX; ii) whereas coincubation with the pure anti-E type II ICI182780 antagonized the inhibitory effect of E2, coincubation with the anti-E type I TX did not; iii) estradiol-17alpha lacked inhibitory action, whereas a dose-dependent inhibitory effect of both E2 and E2 -BSA was noticed; and iv) TRH stimulatory effect on PRL release in pituitaries from TX-treated rats was blocked by addition of E2 to the medium. Taken together, these data argue in favor of the presence of specific membrane recognition sites for E in the lactotrope involved in steroid-specific E2 inhibition of TX-stimulated PRL secretion.

First Report of Globodera rostochiensis in Mallorca Island, Spain

Potato (Solanum tuberosum) is one of the most important crops in the Balearic Islands with a yield of 35,000 t in 2004, distributed in 1,100 ha and mostly located in the Sa Pobla Region of Mallorca Island. Potato cyst nematode (PCN) species are widespread in potato crop regions of the Iberian Peninsula and Canary Islands, but only Globodera pallida is known to be present in Sa Pobla (1) where it causes significant yield reductions if it is not properly managed. In the spring of 2000, goldencolored females were detected in several root samples of plant potatoes. In 2001, 2002, and 2003, soil and root samples were collected at harvest from 28 fields to identify and quantify PCN species in this area. According to the European Plant Protection Organization (EPPO) diagnostic protocol, the identification of Globodera spp. populations was based on: (i) morphological and morphometrics characteristics of cyst vulval area and stylets of second-stage juveniles; (ii) protein electrophoresis patterns by isoelectric focusing (2); and (iii) DNA analysis by random amplified polymorphic DNA polymerase chain reaction techniques (2). PCN infestation was detected in 16 potato fields sampled. Mixed populations of G. rostochiensis and G. pallida were found in 14 fields distributed all around Sa Pobla, while two fields contained only G. pallida. The proportion of G. rostochiensis in mixed populations was low, rarely exceeding 20%. The origin of G. rostochiensis introduction in Mallorca is unknown since there is no direct link with other potato-growing areas of Spain. To our knowledge, this is the first report of G. rostochiensis in the Balearics Islands. The identification of G. rostochiensis in the Sa Pobla potato-production fields is very important for the development of a successful integrated pest management (IPM) program in this region. References: (1) M. L. Martinez-Beringola et al. Nematol. Medit. 15:183, 1987. (2) S. K. Ibrahim et al. Pest Manag. Sci. 57:1068, 2001.

High frequency of APOB gene mutations causing familial hypobetalipoproteinaemia in patients of Dutch and Spanish descent

BACKGROUND

Familial hypobetalipoproteinaemia (FHBL) is an autosomal co-dominant hereditary disorder of lipoprotein metabolism characterised by decreased low density lipoprotein (LDL) cholesterol and apolipoprotein B (APOB) plasma levels. High levels of plasma APOB and LDL cholesterol are strong predictors for risk of cardiovascular disease (CVD), while individuals with low APOB and LDL cholesterol levels are thought to have lower than average risk for CVD, and in fact, heterozygous FHBL patients appear to be asymptomatic.

METHODS

Rather than identifying truncated APOB proteins in plasma fractions separated by gel electrophoresis, which will miss any mutations in proteins smaller than 30 kb, we analysed the APOB gene directly, using PCR.

RESULTS

We identified nine different mutations, six of which are novel. Each mutation showed complete co-segregation with the FHBL phenotype in the families, and statistically significant differences between carriers and non-carriers were found for plasma total, LDL, and HDL cholesterol, triglycerides, and APOB levels, but not for APOA1 levels. All carriers of an APOB mutation were completely free from CVD.

CONCLUSIONS

Prolonged low levels of LDL cholesterol and elevated levels of HDL cholesterol may reduce the progression of atherosclerotic disease, but this has not been unequivocally shown that this is indeed the case in individuals with FHBL, and is the subject of a current study.

Diffusion tensor imaging and voxel based morphometry study in early progressive supranuclear palsy

BACKGROUND

A comprehensive characterisation of grey and white matter changes in progressive supranuclear palsy (PSP), the second most common extrapyramidal syndrome after Parkinson disease, is still not available.

OBJECTIVE

To evaluate grey and white matter changes in mild PSP patients by voxel based morphometry (VBM) and diffusion tensor imaging (DTI), respectively.

METHODS

14 mild PSP patients and 14 healthy controls entered the study and underwent a clinical and neuropsychological evaluation according with a standardised assessment. Each subject had a structural magnetic resonance imaging (MRI) study. Processing analysis of MRI data was carried out according to optimised VBM and fractional anisotropy was determined.

RESULTS

Compared with the controls, in PSP patients VBM analysis showed a significant clusters of reduced grey matter in premotor cortex, frontal operculum, anterior insula, hippocampus, and parahippocampal gyrus, bilaterally. With regard to subcortical brain regions, the pulvinar, dorsomedial and anterior nuclei of the thalamus, and superior and inferior culliculum were affected bilaterally. A bilateral decrease in fractional anisotropy in superior longitudinal fasciculus, anterior part of corpus callosum, arcuate fascicolus, posterior thalamic radiations, and internal capsule, probably involving the cortico-bulbar tracts, was present in PSP patients.

CONCLUSIONS

These data provide evidence for both grey and white matter degeneration in PSP from the early disease stage. These structural changes suggest that atrophy of cortical and subcortical structures and neurodegeneration of specific fibre tracts contribute to neurological deficits in PSP.

Detection of cdtA, cdtB, and cdtC genes in Campylobacter jejuni by multiplex PCR

A multiplex PCR was developed for simultaneous detection of the cytolethal distending toxin (cdt) genes of Campylobacter jejuni. Three primer pairs targeting each one of the cdtA, cdtB and cdtC genes were designed and combined in the same PCR reaction. The assay was evaluated with 100 C. jejuni strains recovered from humans and animals and it was found to be rapid and specific. Two isolates presented several deletions affecting both cdtA and cdtB genes. High prevalence (98%) of the three cdt genes was found among isolates of different geographic origins.

Study of the genetic origin of the Mexican creole donkey (Equus asinus) by means of the analysis of the D-loop region of mitochondrial DNA

The aim of this work was to analyse the genetic origin of the Mexican Creole donkey, as well as its genetic diversity, by comparison with Spanish and African donkey populations by means of the D-loop region of mitochondrial DNA. To this end, the genomic DNA of 68 Mexican Creole donkeys from eight geographical regions in six States of the Republic of Mexico and from a Sicilian donkey was obtained. By the polymerase chain-reaction technique (PCR) a fragment of 541 bp was amplified, corresponding to the most informative region of the mitochondrial DNA, the D-loop. The fragments were subsequently sequenced. The analysed sequences revealed 10 new Mexican haplotypes that were different from those of the Spanish and African breeds with which they were compared, showing high levels of genetic diversity. Analysis of the phylogenetic relationships in the different Creole varieties showed a tendency of origin towards Spanish breeds, mainly the Andaluza, Zamorano-Leonesa and Majorera from the Canary Islands; these in turn showed an African origin, seven Mexican haplotypes and three haplotypes similar to those analysed by Aranguren and colleagues (2004) of Spanish and African breeds being obtained. This work allows us to reach the preliminary conclusion that the origin of Mexican Creole donkey populations in the different states of the Republic of Mexico is clearly of Iberian origin, the Spanish donkey breed Andaluza being the main one contributing to the populations of the Mexican Creole donkeys, followed by the Spanish breeds Zamorano-Leonesa and Majorera from the Canary Islands, and that the populations possess high levels of genetic diversity.

Exotic pets are new allergenic sources: allergy to iguana

Although furry animals are known sources of respiratory allergy, scaly animals are assumed not to be allergenic. Exotic animals such as iguanas are becoming increasingly common pets. Nevertheless, these animals are not suspected to be allergenic. We present the case of a 42-year-old woman suffering from allergic rhinoconjunctivitis and asthma caused by a pet iguana. Clear IgE-sensitization and respiratory allergy to iguana scales is demonstrated, suggesting that scaly pets should be taken into account as possible allergenic sources.

Could the homologous sequence of anti-inflammatory pentapeptide (MLIF) produced by Entamoeba histolytica in the N protein of rabies virus affect the inflammatory process?

Amebiasis and rabies are public health problems, and they have in common a poor inflammatory effect in the target organs that they affect. In the GenBank, it was found that the anti-inflammatory peptide monocyte locomotion inhibitory factor (MLIF) produced by Entamoeba histolytica homologates 80%, with a fragment of the N protein of the rabies virus. We speculated if the N protein could contribute to the scant inflammatory reaction produced by rabies virus in central nervous system. The N protein was obtained and studied in vitro and in vivo. The N protein, as MLIF, inhibited the respiratory burst in human mononuclear phagocytes (43%, p<0.05), but in contrast to MLIF, it increased chemotaxis and it did not significantly inhibit delayed hypersensitivity skin reaction to 1-chloro-2-4-dinitrobenzene in guinea pigs. Therefore, the full peptide sequence has to be present or it has to be cleaved-free from the large recombinant N protein molecule (55 kDa) to become active.

MAMA-PCR assay for the detection of point mutations associated with high-level erythromycin resistance in Campylobacter jejuni and Campylobacter coli strains

Twenty Campylobacter jejuni and 16 Campylobacter coli strains isolated from humans and food/animals, including 17 isolates resistant to erythromycin, were analyzed. A combined mismatch amplification mutation assay-PCR technique was developed to detect the mutations A 2074 C and A 2075 G in the 23S rRNA gene associated with erythromycin resistance. All high-level erythromycin-resistant strains examined by DNA sequencing carried the transition mutation A 2075 G, whereas no isolate carried the A 2074 C mutation. No mutations were found among the susceptible and low-level erythromycin-resistant strains.

Screening of APOB gene mutations in subjects with clinical diagnosis of familial hypercholesterolemia

Monogenic hypercholesterolemia is a group of lipid disorders, most of which have autosomal dominant transmission. Familial defective apoB (FDB) resulting from mutations in the APOB gene is a well-recognized cause of autosomal dominant monogenic hypercholesterolemia (ADMH). However, the frequency of FDB among patients with ADMH is not well established. The aim of our research was to screen for mutations responsible for FDB in subjects with a clinical diagnosis of familial hypercholesterolemia. We studied 408 patients from the Spanish Register of Familial Hypercholesterolemia, proportionally distributed among all Spanish regions. Abnormal SSCP patterns of the APOB gene were checked by DNA sequencing and restriction analysis. Three out of the 408 patients were carriers of the R3500Q mutation, and 2 subjects were carriers of the silent T3552T mutation; in both of these patients functional mutations in the LDL receptor gene were found. We conclude that FDB is not a common cause of ADMH in Spain; the R3500Q mutation is the only mutation in APOB causing FDB, and the LDL receptor binding domain of APOB is highly conserved in the studied sample.

Clinical manifestations, treatment and control of infections caused by Clostridium difficile

Clostridium difficile should be suspected in patients who present with nosocomial diarrhoea. It is more common in the elderly or in patients with a debilitating underlying condition who have received antimicrobial agents, and up to 20-25% of patients may experience a relapse. The reference method for diagnosis is the cell culture cytotoxin test which detects the presence of toxin B in a cellular culture of human fibroblasts, but recovering C. difficile in culture allows the performance of a ''second-look" cell culture assay that enhances the potential for diagnosis. Oral metronidazole (500 mg tid or 250 mg every 6 hrs) and oral vancomycin (125 mg every 6 hrs) administered for 1014 days have similar therapeutic efficacy, with response rates near 90-97%. C. difficile strains resistant to metronidazole and with intermediate resistance to vancomycin have been described. The administration of probiotics such as Saccharomyces boulardii, Lactobacillus sp. or brewer's yeast for prophylaxis of CDAD remains controversial.

Tendon Xanthomas in Familial Hypercholesterolemia Are Associated With Cardiovascular Risk Independently of the Low-Density Lipoprotein Receptor Gene Mutation

OBJECTIVE

To investigate the significance of tendon xanthomas (TX) in heterozygous subjects with familial hypercholesterolemia (hFH).

METHODS AND RESULTS

951 men and women with genetic diagnosis of hFH were studied, of whom 278 (29.2%) presented TX. TX frequency increased with age from 6.9% in subjects 20 to 30 years to 38.3% at 51 to 60 years, with a decrease in those older than 60 years. Total and low-density lipoprotein (LDL) cholesterol were higher in TX+ than in TX- subjects (439.0+/-78.5 mg/dL and 363.1+/-76.5 mg/dL versus 400.6+/-73.4 and 323.3+/-71.0, respectively; P=0.001). High-density lipoprotein (HDL) cholesterol was lower in TX+ than in TX- subjects (50.4+/-15.0 mg/dL versus 53.1+/-14.8 mg/dL; P=0.005). Lp(a), apolipoprotein E genotype, and type of LDL receptor gene mutation showed no differences between groups. 102 TX+ reported premature cardiovascular disease (CVD) (36.7%) versus 93 TX- (13.8%) (P=0.001). The relative odds for premature CVD were higher in women (4.49 versus 2.26), and increased in hFH younger than 51 years to 3.60 (95% CI, 1.703 to 7.608) in men and to 17.1 (95% CI, 2.697 to 108.920) in women. In the multivariate analysis, age, male sex, LDL cholesterol, and hypertension showed significant positive association with TX, whereas body mass index showed negative association with TX.

CONCLUSIONS

TX are associated with cardiovascular risk factors and higher CVD, indicating that their detection indicates the need for more aggressive lipid-lowering intervention.