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J M Alonso

Publications and source records attributed to J M Alonso.

At least 19 recordsLinked to original sources
PubMed2006

Presence of Shiga toxin-producing E. coli O157:H7 in a survey of wild artiodactyls.

This study was carried out to evaluate the role of wild artiodactyls as reservoirs of Escherichia coli O157:H7 for livestock and humans. Retroanal mucosal swabs samples from 206 red deer (Cervus elaphus), 20 roe deer (Capreolus capreolus), 6 fallow deer (Dama dama) and 11 mouflon (Ovis musimon), collected during the hunting season (autumn-winter) in South-western Spain, were screened. Samples were pre-enriched in modified buffered peptone water, concentrated by an immunomagnetic separation technique and cultured onto selective cefixime tellurite sorbitol MacConkey agar. Polymerase chain reaction (PCR) was used to detect the presence of genes coding O157 and H7 antigens and the virulence factors verocytotoxin, intimin and enterohaemolysin. Three E. coli O157:H7 isolates were obtained from red deer (1.5%). Two of them showed inability to ferment sorbitol and lack of beta-d-glucuronidase (GUD) activity, however, the other strain investigated was an atypical sorbitol-fermenting E. coli O157:H7 with GUD(+) activity. This is the first report pointing to red deer as a reservoir of E. coli O157:H7 in Spain.

Adhesins, Bacterial↗
PubMed2006

ACTN3 genotype in professional endurance cyclists.

The Z-disk protein alpha-actinin-3 is only expressed in type II muscle fibres, which are responsible for generating forceful contractions at high velocity. Despite the evolutionary conservation of alpha-actinin-3, approximately one in every five Caucasians of European ancestry is totally deficient in this protein, due to homozygosity for a R577X polymorphism in the ACTN3 gene. This, together with the results of recent research on elite athletes, suggests that the "null" XX polymorphism might confer some advantage to endurance performance events. To test this hypothesis, we studied the frequency distribution of R577X genotypes in a group of 50 top-level male professional cyclists (26.9 +/- 0.4 yrs [mean +/- SEM]; VO2max: 73.5 +/- 0.8 ml x kg (-1) x min (-1)). Their results were compared with those of a group of 52 Olympic-class male endurance runners (26.8 +/- 0.6 yrs; VO2max: 73.3 +/- 0.8 ml x kg (-1) x min (-1)) and 123 healthy, sedentary male controls. All subjects were Caucasian, and of European ancestry. No significant differences (p > 0.05) were found between groups: RR: 28.5 %; RX: 53.6 % and XX: 17.9 % in controls; RR: 28.0 %; RX: 46.0 % and XX: 26.0 % in cyclists; and RR: 25.0 %; RX: 57.7 %; XX: 17.3 % in runners). No differences were found in indices of endurance performance (VO2peak or ventilatory thresholds) between athlete carriers of each R577X genotype. In summary, although the alpha-actinin-3 deficient XX genotype may be detrimental for sprint performance in humans, the R577X polymorphism of the ACTN3 gene does not appear to confer an advantage on the ability of male athletes to sustain extreme endurance performance.

Actinin↗
PubMed2005

Bovine tuberculosis in wild boar (Sus scrofa), red deer (Cervus elaphus) and cattle (Bos taurus) in a Mediterranean ecosystem (1992-2004).

During the last 12 years, an increasing frequency in condemnation of hunted red deer and wild boar carcasses due to the presence of tubercle-like lesions has been observed in Extremadura (Western Spain). Before 1993, tuberculosis was a very rare finding in hunted animals. The current tuberculosis regional prevalence in cattle approaches 0.4% after years of expensive test and slaughter campaigns. It is imperative to investigate the epidemiology of Mycobacterium bovis infection in red deer and wild boar in order to keep a good health status and to maintain the effectiveness of domestic species TB eradication programs. The present paper evaluates the problem in Sierra de San Pedro, estimating the prevalence of TB in wild boar and red deer, the main wild artiodactyls in the area, and domestic cattle since 1992-2004, by the use of a low-cost surveillance method based on detailed pathological inspection of hunted animal carcasses. Microbiology and molecular epidemiology studies on several M. bovis isolates from domestic and wild animals helped to define the interspecies contacts. These findings, as well as recent history of game estates management and descriptive epidemiology field work, throw light on the rise and maintenance of these epizootics.

Animals↗
PubMed2005

Prevalence, serotypes and virulence genes of Shiga toxin-producing Escherichia coli isolated from ovine and caprine milk and other dairy products in Spain.

The aim of this study was to determinate the prevalence, serotypes and virulence genes of Shiga toxin-producing Escherichia coli (STEC) strains isolated from different dairy products (DP) in Spain with the purpose of determining whether DP represent a potential source of STEC pathogenic for humans. A total of 502 DP were examined from 64 different ovine and caprine flocks and 6 dairy plants in Extremadura (Western Spain). Samples were collected monthly between March 2003 and June 2004 and included 360 unpasteurised milk obtained from the bulk tank, 103 fresh cheese curds and 39 cheeses. Samples obtained were examined for STEC using genotypic (PCR) methods. STEC strains were detected from 39 (10.8%) bulk tank, 4 (3.9%) fresh cheese curds and 2 (5%) cheese, whereas O157:H7 serotype were isolated from one (0.3%) bulk tank. A total of 9 STEC strains (O27:H18, O45:H38, O76:H19, O91:H28, O157:H7, ONT:H7, ONT:H9 and ONT:H21) were identified in this study. One of them, the serotype O27:H18, has not been reported previously as STEC. PCR showed that 3 strains carried stx1 genes, 5 possessed stx2 genes and 1 both stx1 and stx2. Whereas all STEC caprine isolates showed ehxA genes, only O157:H7 serotype showed eae virulence genes. The strain O157:H7 isolated possessed intimin type gamma1 and belonged to phage type 31. This study confirms that dairy product is an important reservoir of STEC pathogenic for humans.

Animals↗
PubMed2005

Molecular epidemiology of bovine tuberculosis in wild animals in Spain: a first approach to risk factor analysis.

In human tuberculosis (Mycobacterium tuberculosis), molecular epidemiology has accurately indicated the risk factors involved in active transmission of the disease, by comparing individuals whose isolates belong to a cluster with patients whose strains are considered unique. Nevertheless, this application has not been used in bovine tuberculosis (Mycobacterium bovis). Our study describes the integration of epidemiological data into molecular classification data on M. bovis isolates. These were isolated from wild ungulates in Extremadura (western Spain) with the objective of detecting the risk factors linked to the association of strains in clades, which are indicators of the active spread of the disease. The molecular markers used were spoligotyping + VNTR typing (loci: VNTR 2165, VNTR 2461, VNTR 0577, VNTR 0580, VNTR 3192 VNTR 2163a and VNTR 2163b) on a population of 59 M. bovis strains isolated from deer (Cervus elaphus), 112 from wild boar (Sus scrofa), six from bovines, 28 from pigs and 2 from goats (n=207). Epidemiological variables included the animal species from which the strain was isolated, pathological condition of the host (incipient lesion, early and late generalisation), date of sampling (during or after the reproductive period) and hunting season. Bivariant analysis was used to establish the risk factors connected to the association of strains and later, the variables were evaluated by means of logistic regression. Molecular typing grouped a total of 131 strains (64.21%) in 28 clusters and 76 isolates shows unique profiles. The association of strains was connected to the appearance of macroscopic lesions during the reproductive period (O.R. 4.80; 95% CI 1.09-22.99, P<0.005), showing a possible higher transmission during the courting period. This happened mainly during the last hunting season analysed (2002-2003, O.R. 3.69; 95% CI 1.27-11.9, P<0.05), clashing with the time of higher prevalence of the disease in wild ungulates. Active spread was not connected to any species in particular, or to any concrete pathological condition.

Animals↗
PubMed2005

An epidemiological evaluation of Mycobacterium bovis infections in wild game animals of the Spanish Mediterranean ecosystem.

Recreational hunting of indigenous wild artiodactyls has been one of the most lucrative and rapidly growing industries in Western Spain over the last five years. In the absence of careful ecological management, one consequence of the commercial exploitation of this natural resource has been the appearance of outbreaks of infectious disease; most notably bovine tuberculosis. From the outset of the study in 1997, we have observed a steady increase in prevalence of Mycobacterium bovis (M. bovis) in both species reaching 1.74 (+/-0.17) in deer in 2002 and 2.32 (+/-0.24) in wild boar. The latter species seems to be most severely affected with pulmonary lesions appearing more chronic than those observed in deer. In this study, we describe the epidemiology of M. bovis in European wild boar (Sus scrofa) and Iberian red deer (Cervus elaphus hispanicus) in Extremadura (W. Spain); a region where there are large areas of natural habitat for these species.

Animals↗
PubMed2005

[Neisseria meningitidis infection. Clinical criteria orienting towards a deficiency in the proteins of the complement].

OBJECTIVE: Complement protein deficiency of the classical pathway or in proteins of the alternate pathway is rare but considerably increase the risk of infection with Neisseria meningitidis. The aim of this study was to determine the clinical criteria of the group at risk. METHODS: Retrospective study of the clinical and biological data of patients exhibiting complement protein deficiency associated with one or several N. meningitidis infections. RESULTS: Forty cases were studied, including 35 classical pathway protein deficiencies, with a predominance of C7 deficiency, 3 properdin deficiencies and 2 acquired C3 deficiencies. More than 60% of the patients exhibited recurrent N. meningitidis infections. Serogroups of rare strains were isolated in 50% of cases. Properdin deficiency was associated with a fulminating form in 2 cases out of 3. The age at onset of the first manifestations varied from 2 months to 32 years. CONCLUSION: A deficiency must be systematically searched for in all patients presenting with a N. meningitidis infection before the age of 6 months or after the age of 5 years. Identification of deficient patients permits the proposal of family screening and appropriate prophylaxis, including preventive vaccination.

Adolescent↗
PubMed2004

A computational tool to simulate correlated activity in neural circuits.

A new computational approach to study correlated neural activity is presented. Simulating Elementary Neural NEtworks for Correlation Analysis (SENNECA) is a specific-purpose simulator oriented to small circuits of realistic neurons. The model neuron that it implements can reproduce a wide scope of integrate-and-fire models by simply adjusting the parameter set. Three different distributions of SENNECA are available: an easy-to-use web-based version, a Matlab (Windows and Linux) script, and a C++ class library for low-level coding. The main features of the simulator are explained, and several examples of neural activity analysis are given to illustrate the potential of this new tool.

Animals↗
PubMed2004

Outbreak in France of Neisseria meningitidis B:15:P1.12 belonging to sequence type 1403.

This report describes a meningococcal outbreak in France caused by Neisseria meningitidis B:15:P1.12 of sequence type 1403, which affected eight young patients, between November 2000 and February 2002. Epidemiological typing confirmed that a single strain was responsible. Favourable outcome, sequelae or death resulted in similar proportions as in other cases of meningococcal disease in France during the same period, but purpura was observed in all eight cases. The patients were aged between 14 and 28 years, whereas the median age of patients affected by other meningococcal strains during this period in the same area was 60.4 years.

Adolescent↗
PubMed2004

Mutations in the hereditary haemochromatosis gene HFE in professional endurance athletes.

BACKGROUND: Hereditary haemochromatosis, a disease that affects iron metabolism, progresses with a greater or lesser tendency to induce iron overload, possibly leading to severe organ dysfunction. Most elite endurance athletes take iron supplements during their active sporting life, which could aggravate this condition. OBJECTIVE: To determine the prevalence and discuss potential clinical implications of mutations of HFE (the gene responsible for hereditary haemochromatosis) in endurance athletes. METHODS: Basal concentrations of iron, ferritin, and transferrin and transferrin saturation were determined in the period before competition in 65 highly trained athletes. Possible mutations in the HFE gene were evaluated in each subject by extracting genomic DNA from peripheral blood. The restriction enzymes SnaBI and BclI were used to detect the mutations 845G-->A (C282Y) and 187C-->G (H63D). RESULTS: Our findings indicate a high prevalence of HFE gene mutations in this population (49.2%) compared with sedentary controls (33.5%). No association was detected in the athletes between mutations and blood iron markers. CONCLUSIONS: The findings support the need to assess regularly iron stores in elite endurance athletes.

Adult↗
PubMed2003

Epidemiology of Mycobacterium bovis infections of pigs and wild boars using a molecular approach.

A molecular epidemiological approach was applied to establishing a possible role for the wild boar as a natural reservoir of Mycobacterium bovis in Sierra de Villuercas, Western Spain; an area free of farmed cattle and wild deer populations. Spoligo and VNTR typing were used over a three year period to study the epidemiological relationship between the occurrence of bovine tuberculosis (TB) in extensively bred Iberian pigs and indigenous wild boar. The 37 sampled wild boar showed different degree of calcified granulomatous lesions in retropharyngeal, mediastinal and pulmonary lymph nodes. The 25 sampled Iberian pigs showed calcified lesions, mainly in the respiratory tract. Lesions located in the mesenteric lymph nodes appeared secondarily. M. bovis was isolated from all affected animals. Twenty-five and 37 isolates of M. bovis were obtained from domestic pigs and wild boar, respectively. Our findings provide evidence that supports the possibility of cross infection between wild boar and domestic pig populations. This is contrary to the generally held belief that swine represent an epidemiological dead end host and play no role in the epidemiology of M. bovis.

Animals↗
PubMed2003

Serotypes, virulence genes, and intimin types of Shiga toxin (verotoxin)-producing Escherichia coli isolates from healthy sheep in Spain.

Fecal swabs obtained from 1,300 healthy lambs in 93 flocks in Spain in 1997 were examined for Shiga toxin-producing Escherichia coli (STEC). STEC O157:H7 strains were isolated from 5 (0.4%) animals in 4 flocks, and non-O157 STEC strains were isolated from 462 (36%) lambs in 63 flocks. A total of 384 ovine STEC strains were characterized in this study. PCR showed that 213 (55%) strains carried the stx(1) gene, 10 (3%) possessed the stx(2) gene, and 161 (42%) carried both the stx(1) and the stx(2) genes. Enterohemolysin (ehxA) and intimin (eae) virulence genes were detected in 106 (28%) and 23 (6%) of the STEC strains, respectively. The STEC strains belonged to 35 O serogroups and 64 O:H serotypes (including 18 new serotypes). However, 72% were of 1 of the following 12 serotypes: O5:H-, O6:H10, O91:H-, O117:H-, O128:H-, O128:H2, O136:H20, O146:H8, O146:H21, O156:H-, O166:H28, and ONT:H21 (where NT is nontypeable). Although the 384 STEC strains belonged to 95 different seropathotypes (associations between serotypes and virulence genes), 49% of strains belonged to only 11. O91:H- stx(1) stx(2) (54 strains) was the most common seropathotype, followed by O128:H- stx(1) stx(2) (33 strains) and O6:H10 stx(1) (25 strains). Three strains of serotypes O26:H11, O156:H11, and OX177:H11 had intimin type beta1; 5 strains of serotype O157:H7 possessed intimin type gamma1; and 15 strains of serotypes O49:H-, O52:H12, O156:H- (12 strains), and O156:H25 had the new intimin, intimin type zeta. The majority (82%) of ovine STEC strains belonged to serotypes previously found to be associated with human STEC strains, and 51% belonged to serotypes associated with STEC strains isolated from patients with hemolytic-uremic syndrome. Thus, this study confirms that healthy sheep are a major reservoir of STEC strains pathogenic for humans.

Adhesins, Bacterial↗
PubMed2003

Long term cryostorage of UC blood units: ability of the integral segment to confirm both identity and hematopoietic potential.

BACKGROUND: With the maturation of UC blood banking, cord blood (CB) units stored for years prior to use in transplantation present a new set of issues in clinical transplantation, including interval improvements in immune typing and confirmation of product identity and viability. A preliminary analysis of the transplants supported by the St Louis Cord Blood Bank, looking for an impact of length of CB storage time and transplant outcome was performed. We evaluated the utility of an integral segment containing an aliquot of cryopreserved product that has been exposed to the same post-processing storage conditions as the unit as a quality control tool for CB banking. METHODS: Engraftment and survival following unrelated donor UC blood transplant were evaluated based on length of CB product storage at the St Louis Cord Blood Bank. A strategy of routine testing of the contiguous segment for high-resolution HLA typing (also confirming identity) and CFU analysis was tested in 283 consecutive CB searches. Comparison between CB unit and contiguous segment viability and hematopoietic potential was performed on 30 research CB units that had been stored up to 5 years. RESULTS: There was no statistical difference in engraftment or survival following unrelated donor cord blood transplant employing units banked < 1 year or > 3 years. Confirmatory HLA typing, CFU and viability testing was successfully performed from the same segment as part of a strategy for product release evaluation. When comparing the segment with its corresponding CB unit, the total colony-forming units (CFU) measured in the two was similar (P = 0.51, paired t-test). Three research units purposely sabotaged by an overnight thaw and refreeze had no CFU growth, but viability as measured by Trypan was still 68-98%. DISCUSSION: No deterioration of hematopoietic potential has been detected with storage up to 5 years. The contiguous segment CFU is representative of the product, and thus is a useful tool for quality control and confirmation of product viability. Viability, as measured by Trypan blue dye exclusion may be falsely reassuring.

Blood↗
PubMed2003

Occupational rhinitis and bronchial asthma due to TBTU and HBTU sensitization.

Exposure to an increasing amount of products in the work environment is leading to new cases of occupational asthma among workers. We report the case of a worker at a pharmaceutical plant who developed occupational rhinitis and bronchial asthma due to HBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate and TBTU: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate sensitization, two chemical products widely used in peptide synthesis and coupling. Skin tests (prick test) with HBTU and TBTU solutions in PBS were positive at a concentration of 1 mg/ml. Skin tests with the same solutions in 10 atopic controls yielded a negative result. Nasal challenge tests with these products were positive with HBTU at a concentration of 0.01 mg/ml and TBTU at a concentration of 1 mg/ml. In both cases PNIF (peak nasal inspiratory flow) decreased by more than 60% and severe sneezing and rhinorrhea were induced. Nasal challenge tests performed on 10 atopic controls with TBTU and HBTU at a concentration of 1 mg/ml were negative. We conclude that the patient presents occupational rhinitis and bronchial asthma due to TBTU and HBTU; the operational mechanism is probably immunological IgE-mediated given the positive prick tests and nasal challenge with these products.

Adult↗
PubMed2002

A simple random amplified polymorphic DNA genotyping method for field isolates of Dermatophilus congolensis.

Dermatophilus congolensis is the pathogenic actinomycete that causes dermatophilosis in cattle, lumpy wool in sheep and rain scald in horses. Phenotypic variation between isolates has previously been described, but its genetic basis, extent and importance have not been investigated. Standard DNA extraction methods are not always successful for D. congolensis due to its complex life cycle, one stage of which is encapsulated. Here we describe the development of rapid and reliable DNA extraction and random amplified polymorphic DNA (RAPD) methods that can be used for genotyping D. congolensis field isolates. Our results suggest that genotypic variation between isolates correlates with host species. Several DNA extraction methods and RAPD protocols were compared. An extraction method based on incubation of the bacterium in lysozyme, sodium dodecyl sulphate (SDS) and proteinase K treatments and phenolic extraction yielded high-quality DNA, which was used to optimize RAPD-polymerase chain reaction (PCR) protocols for two random primers. An alternative rapid, non-phenolic extraction method based on proteinase K treatment and thermal shock was selected for routine RAPD typing of isolates. DNA extracted from reference strains from cattle, sheep and horse using either method gave reproducible banding patterns with different DNA batches and different thermal cyclers. The rapid DNA extraction method and RAPD-PCR were applied to 38 D. congolensis field isolates. The band patterns of the field and type isolates correlated with host species but not with geographical location.

Actinomycetales↗
PubMed2002

[Clonal expansion of Neisseria meningitidis W135. Epidemiological implications for the African meningitis belt].

Meningococcal meningitis occur as large epidemics in the "African meningitis belt" described by L. Lapeyssonnie. Neisseria meningitidis serogroup A, clone III-I, was involved in recent epidemics and immunization with A and C vaccine was therefore adequate. However, we report here the emergence of a new clone of N. meningitidis of serogroup W135 during the 2001 epidemics in Niger and in Burkina Faso and discuss the implications of this new epidemiological feature for future surveillance and vaccine strategies.

Bacterial Typing Techniques↗
PubMed2001

A novel use of Grubbs' carbene. Application to the catalytic deprotection of tertiary allylamines.

[reaction--see text] The first examples accounting for the catalytic deprotection of allylic amines by using reagents different from palladium catalysts have been achieved via Grubbs' carbene-mediated reaction. The current mechanistic hypothesis invokes a nitrogen-assisted ruthenium-catalyzed isomerization, followed by hydrolysis of the enamine intermediate. We believe that an unprecedented mode of ring opening of the ruthenacyclobutane was involved.

Journal Article↗