Queratitis secundaria a Fusarium spp. en España 2012-2014 / Keratitis secondary to Fusarium spp. in Spain 2012-2014

OBJETIVO: Describir las características clinicoepidemiológicas de una serie de casos de queratitis fúngica asociada con Fusarium spp., en España durante los años 2012 a 2014. MÉTODOS: Estudio retrospectivo de una serie de casos. Se identificaron los centros sanitarios que se encontraban en las capitales provinciales (n = 250), obteniéndose una muestra aleatoria sistemática del 10%. Se les preguntó si habían presentado casos de queratitis por Fusarium spp. caracterizados mediante métodos microbiológicos, 23 centros respondieron, detectando casos en 14 de ellos, aceptando participar 13, completando el estudio 11 instituciones, a los que se les envió el cuestionario previamente validado. Las variables analizadas fueron: edad, sexo, residencia habitual, profesión, antecedentes patológicos y médicos (enfermedades sistémicas y oculares previas, cirugías oculares previas) y su evolución. RESULTADOS: La tasa de respuesta fue del 92%, identificando 23 casos de Fusarium spp.; 21 casos (91,3%) vivían en zonas urbanas. Los profesionales fueron los más afectados por la enfermedad (chef, administrativo, técnico) con 13 casos (56,5%). Las pautas de tratamiento establecidas antes de la confirmación de la infección evidenciaron el uso combinado de antibióticos tópicos asociados a agentes antivirales y/o antifúngicos, siendo el principal factor de riesgo el uso de lentes de contacto (86,9%). DISCUSIÓN: Es una enfermedad poco frecuente en nuestro medio, un gran porcentaje de las personas residían en áreas urbanas y su trabajo se realizaba en entornos cerrados, enfocando la atención en los microtraumas causados por el uso de lentes de contacto

OBJECTIVE: To describe the clinical-epidemiological characteristics of a case series of fungal keratitis associated with Fusarium spp.., in Spain during the years 2012 to 2014. METHODS: A retrospective study of a case series was conducted on a systematic random sample of 10% of patients identified in Health Centres of provincial capitals (n = 250). The centres were asked whether they had been presented with cases of Fusarium spp. keratitis characterised by microbiological methods. Of the 23 centres that responded, 14 had detected cases, with 13 of them accepting to participate, and 11 of them completing the study. The latter being sent a previously validated questionnaire. The variables analysed were: age, gender, habitual residence, profession, disease and medical history (previous systemic and ocular diseases, previous eye surgeries), and their outcomes. RESULTS: The response rate was 92%, identifying 23 cases of Fusarium spp.. of which 21 (91.3%) of them lived in urban areas. The professions most affected by the disease included chefs, administrative, and technical, with 13 cases (56.5%). The treatment guidelines established to confirm the infection showed the combined use of topical antibiotics associated with antiviral and/or antifungal agents. The use of contact lenses (86.9%) was the main risk factor. DISCUSSION: This study showed that this is a rare disease in Spain, but that a large percentage of people who present with the disease are resident in urban areas, and they work in closed environments, focusing attention on microtraumas caused by use of contact lenses

Keratitis secondary to Fusarium spp. in Spain 2012-2014. / Queratitis secundaria a Fusarium spp. en España 2012-2014.

OBJECTIVE: To describe the clinical-epidemiological characteristics of a case series of fungal keratitis associated with Fusarium spp.., in Spain during the years 2012 to 2014. METHODS: A retrospective study of a case series was conducted on a systematic random sample of 10% of patients identified in Health Centres of provincial capitals (n=250). The centres were asked whether they had been presented with cases of Fusarium spp. keratitis characterised by microbiological methods. Of the 23 centres that responded, 14 had detected cases, with 13 of them accepting to participate, and 11 of them completing the study. The latter being sent a previously validated questionnaire. The variables analysed were: age, gender, habitual residence, profession, disease and medical history (previous systemic and ocular diseases, previous eye surgeries), and their outcomes. RESULTS: The response rate was 92%, identifying 23 cases of Fusarium spp.. of which 21 (91.3%) of them lived in urban areas. The professions most affected by the disease included chefs, administrative, and technical, with 13 cases (56.5%). The treatment guidelines established to confirm the infection showed the combined use of topical antibiotics associated with antiviral and/or antifungal agents. The use of contact lenses (86.9%) was the main risk factor. DISCUSSION: This study showed that this is a rare disease in Spain, but that a large percentage of people who present with the disease are resident in urban areas, and they work in closed environments, focusing attention on microtraumas caused by use of contact lenses.

Using a model-based framework for analysing genetic diversity during germination and heterotrophic growth of Medicago truncatula.

BACKGROUND AND AIMS: The framework provided by an emergence model was used: (1) for phenotyping germination and heterotrophic growth of Medicago truncatula in relation to two major environmental factors, temperature and water potential; and (2) to evaluate the extent of genetic differences in emergence-model parameters. METHODS: Eight cultivars and natural accessions of M. trunculata were studied. Germination was recorded from 5 to 30 degrees C and from 0 to -0.75 MPa, and seedling growth from 10 to 20 degrees C. KEY RESULTS: Thermal time to reach 50 % germination was very short (15 degrees Cd) and almost stable between genotypes, while base temperature (2-3 degrees C) and base water potential for germination (-0.7 to -1.3 MPa) varied between genotypes. Only 35 degrees Cd after germination were required to reach 30 mm hypocotyl length with significant differences among genotypes. Base temperature for elongation varied from 5.5 to 7.5 degrees C. Low temperatures induced a general shortening of the seedling, with some genotypes more responsive than others. No relationship with initial seed mass or seed reserve distribution was observed, which might have explained differences between genotypes and the effects of low temperatures. CONCLUSIONS: The study provides a set of reference values for M. trunculata users. The use of the ecophysiological model allows comparison of these values between such non-crop species and other crops. It has enabled phenotypic variability in response to environmental conditions related to the emergence process to be identified. The model will allow simulation of emergence differences between genotypes in a range of environments using these parameter values. Genomic tools available for the model species M. trunculata will make it possible to analyse the genetic and molecular determinants of these differences.

AER1, a major gene conferring resistance to Aphanomyces euteiches in Medicago truncatula.

Aphanomyces euteiches is a major soilborne oomycete pathogen that infects various legume species, including pea and alfalfa. The model legume Medicago truncatula has recently emerged as a valuable genetic system for understanding the genetic basis of resistance to A. euteiches in leguminous crops. The objective of this study was to identify genetic determinants of resistance to a broad host-range pea-infecting strain of A. euteiches in M. truncatula. Two M. truncatula segregating populations of 178 F(5) recombinant inbred lines and 200 F(3) families from the cross F83005.5 (susceptible) x DZA045.5 (resistant) were screened for resistance to A. euteiches. Phenotypic distributions observed suggested a dominant monogenic control of resistance. A major locus associated with resistance to A. euteiches, namely AER1, was mapped by bulk segregant analysis to a terminal end of chromosome 3 in M. truncatula and explained 88% of the phenotypic variation. AER1 was identified in a resistance-gene-rich region, where resistance gene analogs and genes associated with disease resistance phenotypes have been identified. Discovery of AER1 opens up new prospects for improving resistance to A. euteiches in cultivated legumes using a comparative genomics approach.

The use of neutral and non-neutral SSRs to analyse the genetic structure of a Tunisian collection of Medicago truncatula lines and to reveal associations with eco-environmental variables.

In this study, we investigated the genetic diversity of a collection of 136 Medicago truncatula lines from 10 Tunisian natural populations collected in well-defined locations and in various ecological conditions of soil, salinity and water availability. The genetic diversity was evaluated using a set of 18 microsatellites (SSRs), representing the 8 chromosomes of M. truncatula. A neutrality test showed that 7 SSRs were non-neutral with evidence of balancing selection. The 11 neutral SSRs revealed a geographical pooling with the Tunisian Dorsale axis restricting migration of alleles. The 7 non-neutral alleles demonstrate a correlation with rainfall, altitude and salinity environmental variables suggesting that these SSRs are linked to genes involved in water use efficiency, resistance to salinity or adaptation to altitude, and that there is local adaptation of M. truncatula to these variables. This demonstrates that the choice of so-called neutral markers should be carefully evaluated in population genetic studies. This study illustrates the genetic diversity occurring in natural Tunisian populations of M. truncatula and describes the first collection of this species dedicated to natural variation involved in adaptation to the environment.

Comparison of rhizobia that nodulate Medicago laciniata and Medicago truncatula present in a single Tunisian arid soil.

The rhizobia present in a single arid region Tunisian soil that nodulate Medicago laciniata and Medicago truncatula were compared. All isolates, 40 from each host, were Sinorhizobium meliloti based on 16S rRNA polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) patterns and subsequent confirmation by sequence analysis of the 16S rRNA genes in four representatives from each host species. There was no apparent relationship between Medicago host species of isolation and the nodulating rhizobial genome as determined by repetitive extragenic palandromic PCR. The isolates of M. laciniata were distinguished from those of M. truncatula present in the same soil by variation in PCR-RFLP of nifDK, indicating that this dissimilarity is originally genetic and not geographic. While forming effective symbioses with their own respective isolates, both M. laciniata and M. truncatula formed ineffective true nodules, nodule-like structures, or no nodules at all in cross-inoculation tests, as confirmed by the histological observations.

Functional mapping in pea, as an aid to the candidate gene selection and for investigating synteny with the model legume Medicago truncatula.

The identification of the molecular polymorphisms giving rise to phenotypic trait variability-both quantitative and qualitative-is a major goal of the present agronomic research. Various approaches such as positional cloning or transposon tagging, as well as the candidate gene strategy have been used to discover the genes underlying this variation in plants. The construction of functional maps, i.e. composed of genes of known function, is an important component of the candidate gene approach. In the present paper we report the development of 63 single nucleotide polymorphism markers and 15 single-stranded conformation polymorphism markers for genes encoding enzymes mainly involved in primary metabolism, and their genetic mapping on a composite map using two pea recombinant inbred line populations. The complete genetic map covers 1,458 cM and comprises 363 loci, including a total of 111 gene-anchored markers: 77 gene-anchored markers described in this study, 7 microsatellites located in gene sequences, 16 flowering time genes, the Tri gene, 5 morphological markers, and 5 other genes. The mean spacing between adjacent markers is 4 cM and 90% of the markers are closer than 10 cM to their neighbours. We also report the genetic mapping of 21 of these genes in Medicago truncatula and add 41 new links between the pea and M. truncatula maps. We discuss the use of this new composite functional map for future candidate gene approaches in pea.

Cuantificación de Brucella sp. en bovinos de la provincia de Canta, Lima / Quantification of Brucella sp. in cattle in the province of Canta, Lima

El objetivo del presente estudio fue determinar la presencia de Brucella sp. en el ganado bovino de la provincia de Canta, Lima, mediante la detección de anticuerpos en suero a través de la prueba inicial de Rosa de Bengala y la de Fijación de Complemento como prueba confirmatoria. Se procesaron 486 muestras de suero en toda la provincia encontrándose un animal positivo a Brucella sp. en el distrito de Santa Rosa de Quives, lo que significó una prevalencia de 0.21 por ciento con intervalo de confianza mínimo de 0.09 y máximo de 0.60 por ciento. Los resultados indican una baja prevalencia, lo que permitiría implementar un programa de erradicación de brucelosis bovina en la provincia de Canta.

The objective of this study was to determine the presence of Brucella sp. in cattle of the province of Canta, Lima, through the detection of antibodies in blood using the Rose Bengal test and then, the complement fixation test to confirm positive sera. A total of 486 serum samples were analysed and only one from the district of Santa Rosa de Quives was found positive. This indicated that the prevalence was 0.21 per cent (1/486) with a confidence interval of 0.09 till 0.60 percent. The results showed that the presence of Brucella sp. in the province of Canta was very low, which may allow the implementation of a program for Brucella eradication.

Medicago-Sinorhizobium symbiotic specificity evolution and the geographic expansion of Medicago.

The legume genus Medicago interacts with soil bacteria commonly referred to as rhizobia, in a nitrogen fixing symbiosis. We analysed the diversity of symbiotic association specificity among the two organisms, and its evolution in the plant genus. Nitrogen fixation tests and molecular phylogenetic reconstructions revealed that the genus Medicago includes more symbiotic specificity groups than previously suggested and that plant specificity is highly unstable and has repeatedly switched along the diversification of this genus. A phylogenetic analysis including geographical data shows that bacterial geographical diversity distribution has a strong influence on the geographic distribution of plant species and their ability to colonize new areas. Multiple other modifications of specificity occurred along the diversification of the genus, presumably due to selection for specialization to a single bacterial biovar. Codivergence between plants and bacteria may also have taken place.

Cross-species amplification of Medicago truncatula microsatellites across three major pulse crops.

Model plants are facilitating the genetic characterization and comparative mapping of a number of traditional crops. Medicago truncatula has been widely accepted as a model plant to this end as it provides the essential tools for multiple aspects of legume genetics and genomics. A large set of markers from highly conserved M. truncatula gene regions is being created and used to establish a worldwide framework for comparative genomic studies in legumes. We have investigated the potential for cross-species amplification of 209 expressed sequence tag (EST)-based and 33 bacterial artificial chromosome (BAC)-based microsatellites from M. truncatula in the three most important European legume pulses-pea, faba bean and chickpea-that might facilitate future comparative mapping. Our results revealed significant transferability of M. truncatula microsatellites to the three pulses (40% in faba bean, 36.3% in chickpea and 37.6% in pea). The percentage of M. truncatula EST-SSRs (simple sequence repeats) amplified in the three crops (39-43%) was twofold higher than that of the genomic SSRs (21-24%). Sequence analysis determined that the level of conservation in the microsatellite motif was very low, while the flanking regions were generally well conserved. The variations in the sequences were mainly due to changes in the number of repeat motifs in the microsatellite region combined with indel and base substitutions. None of the functional microsatellites showed direct polymorphism among the parental genotypes tested, consequently preventing their immediate use for mapping purposes.

Escherichia coli enteroagregativa en niños con diarrea de un hospital de Lima / Enteroaggregative escherichia coli in children with diarrhea in a Lima hospital

Entre las Escherichia coli diarreogénicas la categoría E. coli enteroagregativa (ECEA) es una de las más importantes y frecuentemente asociada a diarreas infantiles. El presente estudio se realizó con la finalidad de detectar los factores de virulencia que caracterizan a esta categoría patogénica mediante hibridación por colony blot usando sondas de ADN específicas. Se evaluaron 233 cepas aisladas en el laboratorio del Hospital de Emergencias Pediátricas durante los meses de diciembre 1998 y abril de 1999. Del total de muestras analizadas, se encontró que 17,16 por ciento de las cepas poseen el factor de virulencia característico de esta categoría. Los resultados obtenidos demuestran que un importante número de aislamientos de niños con diarrea presentan E. coli enteroagregativa.

Amongst Escherichia coli causing diarrheal disease, enteroaggregative E. coli is one of the most important organisms, and it is frequently associated to diarrhea in infants. The study was performed aiming at detecting virulence factors for the aforementioned organism, using colony blood hybridization with specific deoxyribonucleic acid (DNA) probes. 233 samples isolated in the Pediatric Emergency Hospital Laboratory between december 1998 and april 1999. Of all samples analyzed, it was found that 17,16 per cent of them have the typical virulence factor for their category. The resultsprove that an important proportion of isolates in children with diarrheal disease have enteroaggregative E. coli.

Detección molecular de toximas termoestable y termolabil de escherichia coli mediante hibridación / Molecular detection of escherichia coli heat-stable and heat-labile toxin by hibridization

Objetivos:Identificar mediante el método de hibridación por colony blot las toxinas de Escherichia coli enterotoxigénica y relacionar los resultados con los serotipos encontrados. Materiales y métodos: Se evaluaron todas las cepas de E. coli recolectadas en el Hospital de Emergencias Pediátricas de Lima durante los meses de diciembre de 1998 - abril 1999. Se usaron dos sendas de ADN que identificaban el gen de la toxina termolábil (LT) y el de la toxina termoestable (ST). Para la detección de los serotipos se usaron 22 antisueros de diferentes categorias de E. coli. Resultados: Se encontraron 233 cepas de E. coli, 27,9 por ciento de E.coli poseian el gen LT, 3,0 por ciento el gen St y 1,3 por ciento tenían ambos. Conclusiones: Los serotipos y la presencia de los genes LT y ST no necesariamente tienen relación, demostrándose que la identificación serológica es importante en el estudio epidemiológico de diarreas causadas por E. coli debiéndose confirmar la identificación de las categorías patogénicas mediante la detección de factores de virulencia.

Integration of the FISH pachytene and genetic maps of Medicago truncatula.

A molecular cytogenetic map of Medicago truncatula (2n = 2x = 16) was constructed on the basis of a pachytene DAPI karyogram. Chromosomes at this meiotic prophase stage are 20 times longer than at mitotic metaphase, and display a well differentiated pattern of brightly fluorescing heterochromatin segments. We describe here a pachytene karyogram in which all chromosomes can be identified based on chromosome length, centromere position, heterochromatin patterns, and the positions of three repetitive sequences (5S rDNA, 45S rDNA and the MtR1 tandem repeat), visualized by fluorescence in situ hybridization (FISH). We determined the correlation between genetic linkage groups and chromosomes by FISH mapping of bacterial artificial chromosome (BAC) clones, with two to five BACs per linkage group. In the cytogenetic map, chromosomes were numbered according to their corresponding linkage groups. We determined the relative positions of the 20 BACs and three repetitive sequences on the pachytene chromosomes, and compared the genetic and cytological distances between markers. The mapping resolution was determined in a euchromatic part of chromosome 5 by comparing the cytological distances between FISH signals of clones of a BAC contig with their corresponding physical distance, and showed that resolution in this region is about 60 kb. The establishment of this FISH pachytene karyotype, with a far better mapping resolution and detection sensitivity compared to those in the highly condensed mitotic metaphase complements, has created the basis for the integration of molecular, genetic and cytogenetic maps in M. truncatula.

Primer aislamiento de Escherichia coli O157:H7 Enterohemorrágica en el Perú

En Febrero del año 2001 como parte del "Estudio transversal de los agentes etiológicos de diarrea aguda" en la Macrorregión Sur del país, el Laboratorio Referencial de Tacna aisló una cepa procedente de una muestra de heces de un lactante de 11 meses de edad con un cuadro de diarrea disentérica, identificándola como Escherichia coli O157. Esta cepa fue confirmada y caracterizada en el Instituto Nacional de Salud como E. coli O157:H7 toxina shiga tipo II, siendo el primer aislamiento reportado de Escherichia coli enterohemorrágica en el Perú.

In February 2001, as a part of the "Cross-sectional study of the etiology agents of acute diarrea" in the South Macro region of the country, the Reference Laboratory of Tacna isolated a strain from a stool sample of a eleven months breast feeding infant who suffered an episode of dysenteric diarrhea, identifying the strain as Escherichia coli O157. The strain was confirmed and characterized in the National Institute of Health as E. coli O157:H7 which carried a shiga like type II toxin, being the first report of an isolation of enterohemorragic Escherichia coli in Peru.

Tipificación molecular del Vibrio cholerae 01 en el Perú / Molecular typification of Vibrio cholerae 01 from Peru

Este estudio de ribotipificación en 75 cepas de Vibrio cholerae 01 permitió identificar tres variantes ribotípicas, referidas como Per1, Per2 y Per3, aisladas durante el periodo 1991-1999 en el Perú. La variante Per1 fue reportada tanto en la etapa epidémica y endémica del cólera, mientras que Per2 y Per3 se relacionan sólo con la etapa endémica. Los resultados mostraron además una aparición constante y mayoritaria de la variante Per1, poniendo en evidencia la emergencia de un mismo grupo clonal en los brotes epidémicos del Perú. Las variantes ribotípicas encontradas fueron comparadas con los ribotipos de diferentes cepas referenciales de V. cholerae previamente caracterizadas. Se observó una identidad total del ribotipo Per1 con la variante ribotípica de aislamientos Asiáticos (Tailandia), encontrándose además altos índices de similitud entre los ribotipos Per1, Per2 y Per3, y evidenciándose una estrecha relación entre las cepas peuansa y los aislamientos asiáticos

Mtsym6, a gene conditioning Sinorhizobium strain-specific nitrogen fixation in Medicago truncatula.

The availability of a wide range of independent lines for the annual medic Medicago truncatula led us to search for natural variants in the symbiotic association with Sinorhizobium meliloti. Two homozygous lines, Jemalong 6 and DZA315.16, originating from an Australian cultivar and a natural Algerian population, respectively, were inoculated with two wild-type strains of S. meliloti, RCR2011 and A145. Both plant lines formed nitrogen-fixing (effective) nodules with the RCR2011 strain. However, the A145 strain revealed a nitrogen fixation polymorphism, establishing an effective symbiosis (Nod(+)Fix(+)) with DZA315.16, whereas only small, white, non-nitrogen fixing nodules (Nod(+)Fix(-)) were elicited on Jemalong 6. Cytological studies demonstrated that these non-fixing nodules are encircled by an endodermis at late stages of development, with no visible meristem, and contain hypertrophied and autofluorescent infection threads, suggesting the induction of plant defense reactions. The non-fixing phenotype is independent of growth conditions and determined by a single recessive allele (Mtsym6), which is located on linkage group 8.

The early nodulin gene MtN6 is a novel marker for events preceding infection of Medicago truncatula roots by Sinorhizobium meliloti.

MtN6 belongs to a series of cDNA clones representing Medicago truncatula genes transcriptionally activated during nodulation by Sinorhizobium meliloti (P. Gamas, F. de Carvalho Niebel, N. Lescure, and J. V. Cullimore, Mol. Plant-Microbe Interact. 9:233-242, 1996). We show here by in situ hybridization that MtN6 transcripts specifically accumulate first at very localized regions in the outer root cell layers, corresponding to outer cortical cells containing preinfection threads. At later stages, MtN6 expression is observed ahead of growing infection threads, including in the infection zone of mature root nodules. Interestingly, regulation of MtN6 is clearly distinct from that of other early nodulins expressed in the same region of the nodule, in terms of response to bacterial symbiotic mutants and to purified Nod factors. We thus suggest that MtN6 represents the first specific marker of a pathway involved in preparation to infection, which is at least partly controlled by Nod factors. Finally, we discuss the intriguing sequence homology shown by MtN6 to a protein from Emericella (Aspergillus) nidulans, FluG, that plays a key role in controlling the organogenesis of conidiophores (B. N. Lee and T. H. Adams, Genes Dev. 8:641-651, 1994).