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1.
Neotrop Entomol ; 49(5): 780-782, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32557201

ABSTRACT

The state of Bahia ranks fourth in the national rank for citrus production, and the region of Chapada Diamantina is emerging an important producer of orange for fresh fruit market. Huanglongbing (HLB) is the major phytosanitary threat to Bahia citriculture. In Brazil, the disease was first reported in 2004 in São Paulo state. The bacterium Candidatus Liberibacter asiaticus (CLas) is one of the causal agents of HLB, which is transmitted by the insect vector Diaphorina citri Kuwayama (Hemiptera: Liviidae). Bahia is a HLB-free area; therefore, it is essential to monitor its citrus-producing areas to early detect any possible introduction of the CLas. This study aimed to monitor the presence of the bacteria in the insect vector. Diaphorina citri samples were collected from 2011 to 2014 in different cities located at Chapada Diamantina region and tested by qPCR for the presence of CLas. Three samples were considered positive to bacterium, and all from psyllids collected on Murraya paniculata in the city of Seabra.


Subject(s)
Hemiptera/microbiology , Insect Vectors/microbiology , Rhizobiaceae/isolation & purification , Animals , Brazil , Citrus/microbiology , Plant Diseases/microbiology , Rhizobiaceae/pathogenicity
2.
Neotrop Entomol ; 48(3): 503-514, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30554328

ABSTRACT

Diaphorina citri Kuwayama (Hemiptera: Liviidae), named as Asian citrus psyllid (ACP), is the vector of the bacterium associated with huanglongbing (HLB), the most destructive citrus disease. The use of citrus flushing and ACP monitoring tools is essential for the knowledge of the occurrence pattern of cycles of both and for the improvement of the ACP management. During 3 years, 20 branches from 20 trees were evaluated for vegetative flushing, ACP abundance, and occupation in tree and branches in a Brazilian citrus area free for HLB. The obtained data was investigated through spectral and co-spectral analyses. Four to 12 flush shoot cycles occurred per year, which were similar to abundance and occupation cycles of ACP, with an apparent synchronization between these variables. In general, there was a difference from 14 to 19 days between flushing and ACP peaks, with an occurrence of the flushing peaks before the ACP peaks. Results will provide useful information to citrus growers and agricultural defense agencies to apply a suitable and targeted ACP management, which will avoid or delay the disease entrance into still free HLB areas. In addition, the modeling of occupation and abundance cycles of vectors as applied in this study may be useful for other pathosystems which insect vectors are associated or even in the intrusion monitoring programs.


Subject(s)
Citrus/microbiology , Hemiptera/microbiology , Plant Diseases/etiology , Animals , Bacteria/pathogenicity , Brazil , Environmental Monitoring , Insect Vectors/microbiology , Trees
3.
Mol Genet Metab ; 112(2): 160-70, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24726177

ABSTRACT

Morquio A (Mucopolysaccharidosis IVA; MPS IVA) is an autosomal recessive lysosomal storage disorder caused by partial or total deficiency of the enzyme galactosamine-6-sulfate sulfatase (GALNS; also known as N-acetylgalactosamine-6-sulfate sulfatase) encoded by the GALNS gene. Patients who inherit two mutated GALNS gene alleles have a decreased ability to degrade the glycosaminoglycans (GAGs) keratan sulfate and chondroitin 6-sulfate, thereby causing GAG accumulation within lysosomes and consequently pleiotropic disease. GALNS mutations occur throughout the gene and many mutations are identified only in single patients or families, causing difficulties both in mutation detection and interpretation. In this study, molecular analysis of 163 patients with Morquio A identified 99 unique mutations in the GALNS gene believed to negatively impact GALNS protein function, of which 39 are previously unpublished, together with 26 single-nucleotide polymorphisms. Recommendations for the molecular testing of patients, clear reporting of sequence findings, and interpretation of sequencing data are provided.


Subject(s)
Chondroitinsulfatases/genetics , Chondroitinsulfatases/metabolism , Mucopolysaccharidosis IV/genetics , Mutation , Cells, Cultured , Child , Child, Preschool , Female , Genetic Association Studies , Genetic Testing , Genotype , Glycosaminoglycans/metabolism , Humans , Infant , Lysosomes/metabolism , Male , Mucopolysaccharidosis IV/diagnosis , Polymorphism, Single Nucleotide
5.
Article in English | MEDLINE | ID: mdl-11102058

ABSTRACT

A cellular automata model is proposed to analyze the progress of citrus variegated chlorosis epidemics in São Paulo orange plantations. In this model epidemiological and environmental features, such as motility of sharpshooter vectors that perform Lévy flights, level of plant hydric and nutritional stress, and seasonal climatic effects, are included. The observed epidemic data were quantitatively reproduced by the proposed model on varying the parameters controlling vector motility, plant stress, and initial population of diseased plants.


Subject(s)
Citrus/physiology , Models, Biological , Plant Diseases , Biological Evolution , Brazil , Citrus/cytology , Citrus/microbiology , Climate , Computer Simulation , Disease Outbreaks , Plant Diseases/economics , Plant Diseases/microbiology , Seasons , Spores/cytology , Spores/physiology
6.
Tissue Antigens ; 53(3): 237-43, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10203016

ABSTRACT

We have characterized HLA-B27 alleles in a sample of the population from the Azores (n=46) with the aim of investigating the contribution of different subtypes to ankylosing spondylitis (AS). The study was carried out using PCR-SSOP and in some samples genomic sequencing was conducted. Some significant new finding have arisen from this study. First, B*2705,B*2702,B*2703,B*2707 and B*2708 alleles were found to be represented in this population. The polymorphism of B27 alleles found in a sample of the population from the Azores is higher than the Caucasian groups described. B*2703 and B*2707 have not previously been described to be represented in Caucasians and this could indicate admixtures with different populations of the world. In addition, the B*2708 allele was found to be associated with AS in a large family from the Azores. This association has not been previously reported in either ethnic group and needs to be confirmed in other population studies. This is of considerable interest since has only been described as a rare subtype underrepresented in the British population and has not been previously found to be associated with AS. B*2708 carries the sequence specifying the Bw6 epitope in contrast to most B27 alleles which carry a Bw4 sequence. Differences in this region (residues 77-83) can alter the F-pocket and affect T-cell recognition. The importance that these molecular changes can play in the pathogenesis of AS is discussed.


Subject(s)
HLA-B27 Antigen/genetics , HLA-B27 Antigen/immunology , Spondylitis, Ankylosing/genetics , Spondylitis, Ankylosing/immunology , Azores , Black People/genetics , Disease Susceptibility/immunology , Epitope Mapping , Gene Frequency , Genetic Predisposition to Disease , HLA-B Antigens/genetics , HLA-B Antigens/immunology , Humans , Pedigree , White People/genetics
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