Comparison of the genomes of two Xanthomonas pathogens with differing host specificities

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline(1). Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis(2). Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries(3). Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.

Modulation of host cell signaling pathways as a therapeutic approach in periodontal disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

ASSESSING THE SUITABILITY of STERILE INSECT TECHNIQUE APPLIED TO AEDES AEGYPTI

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leaf trait variation on Erythroxylum tortuosum (Erythroxylaceae) and its relationship with oviposition preference and stress by a host-specific leaf miner

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Host specificity of sheep and cattle nematodes in São Paulo state, Brazil

The trial was carried out to investigate parasite host specificity and to analyse the dynamics of infection with nematodes parasitizing sheep and catt:le raised together or separately in São Paulo state, Brazil, and, also to clarify doubts about the systematics of species of the genus Haemonchus on the basis of cytological and morphological studies. Ten steers and 32 ewes were randomly assigned to three paddocks (P), as follows: P1, 5 steers; P2, 5 steers and 16 ewes; and P3, 16 ewes. The animals remained on these paddocks in continuous grazing throughout the trial (1-yr period). Faecal exams and larvae counting on pasture were performed fortnightly. Once a month two tracer lambs were placed in each paddock, while two tracer calves were also placed, but only in the eighth month of the trial. All these animals were slaughtered for worm identification and counting. At the end of the trial, one steer and one ewe from P2, which showed high faecal egg counts, were also slaughtered for the same purpose. Nematodes identified cytogenetically as H. placei presented spicule hooks longer than those identified as H. contortus. The following distribution of parasites in cattle and sheep was observed: Bunostomum phlebotomum, H. similis, Mammomonogamus laryngeus strongly adapted to cattle, H. placei and Cooperia punctata more adapted to cattle than to sheep, Trichostrongylus axel and C. spatulata apparently more adapted to cattle, T. colubriformis strongly adapted to sheep, H. contortus more adapted to sheep than to cattle and C. curticei apparently more adapted to sheep. Cross-infection was shown to occur involving some species, however, with time the animals apparently eliminate the species that are not well adapted to them. Therefore, grazing management systems using cattle and sheep appear to be promising for worm control in southeastern Brazil. (C) 1997 Elsevier B.V. B.V.

Brown-throated three-toed sloth (Bradypus variegatus Shinz, 1825) as a new host for Leiuris leptocephalus (Rud., 1819) Leuckard, 1850

Vinte e três espécimes de Leiuris leptocephalus (Rud., 1819) Leuckard 1850 (Spirocercidae) foram recuperados do intestino delgado de uma fêmea de preguiça comum, Bradypus variegatus Shinz 1825 (Bradipodidae), em Ubatuba, estado de São Paulo. Os dados demonstram maior variabilidade morfométrica em relação aos dados da literatura, o que contribui para a caracterização morfológica desse nematódeo. Essa comunicação corresponde ao primeiro relato de B. variegatus como hospedeiro de L. leptocephalus.

New host records of Brazilian pentastomid species

Pentastomida é um táxon de organismos parasitas obrigatórios de sistema respiratório de vertebrados, principalmente répteis. Embora esse táxon seja muito importante para a compreensão da filogenia dos Metazoa, tem recebido pouca atenção. No Brasil, existem poucas coleções que abrigam espécies de pentastomídeos, quais sejam: a Coleção Helmintológica do Instituto Oswaldo Cruz (CHIOC), a Coleção de Invertebrados do Laboratório de Zoologia da Universidade Regional do Cariri (LAZ-URCA) e a Coleção Helmintológica do Laboratório de Parasitologia de Animais Silvestres (LAPAS). O presente trabalho descreve as espécies de pentastomídeos depositados na Coleção Helmintológia do LAPAS. O trato respiratório e as cavidades do corpo dos répteis foram removidos e analisados sob Microscópio Esteroscópico; quando encontrados os pentastomídeos, foram montados slides em meio Hoyer e identificados. Foram identificadas quatro espécies e outras três ficaram identificadas no nível de gênero, tendo sido registrados quatro novos hospedeiros para as espécies de pentastomídeos.

A NEW HOST RECORD, PALAEMONETES CARTERI (GORDON, 1935) (DECAPODA, PALAEMONIDAE), FOR TELOTHA HENSELII (VON MARTENS, 1869) (ISOPODA, CYMOTHOIDAE)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Annelida, Hirudinida, Stibarobdella moorei (Oka, 1910): new distribution and host records.

The present report is the northernmost capture of the piscicolid leech Stibarobdella moorei in the western South Atlantic Ocean. This is also the first time S. moorei is found associated to a batoid fish in the Brazilian coast, the eyespot skate Atlantoraja cyclophora. Stibarobdella moorei was found fixed in the dorsal side of a male eyespot skate, caught by bottom trawl around of the São Paulo coast, southeastern Brazil. A brief description of the morphology of the parasite and a discussion on the taxonomic status of the S. moorei are presented.

Mistletoes Play Different Roles in a Modular Host-Parasite Network

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relationship between number of ovipositions of Cotesia flavipes (Cam.) and number of descendants emerged from its host Diatraea saccharalis (Fabr.)

Fêmeas de Cotesia flavipes (Cam.) foram introduzidas, individualmente, em placas de Petri contendo uma larva de seu hospedeiro Diatraea saccharalis (Fabr.). Permitiu-se que cada fêmea de C. flavipes realizasse posturas uma ou duas vezes em uma mesma larva. O período de emergência das larvas e dos adultos, a razão sexual, o número de larvas e pupas inviáveis e a longevidade dos adultos de C. flavipes registrados nas duas condições experimentais (uma ou duas posturas) foram comparados. Os resultados revelaram que duas oviposições sucessivas no hospedeiro não alteraram a razão sexual na descendência, mas aumentaram o número de parasitóides e também o número de larvas e pupas inviáveis.

Habitat suitability of Anopheles vector species and association with human malaria in the Atlantic Forest in south-eastern brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suitability of DNA extracted from archival specimens of fruit-eating bats of the genus Artibeus (Chiroptera, Phyllostomidae) for polymerase chain reaction and sequencing analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Voltage-composition profile and synchrotron X-ray structural analysis of low and high temperature LixCoO2 host material

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tropidurus hispidus Spix 1825 (Sauria, Tropiduridae): a new host for Oswaldofilaria petersi Bain & Sulahian 1974 (Nematoda, Onchocercidae)

No presente trabalho descreve-se a ocorrência de Oswaldofilaria petersi Bain & Sulahian 1974 (Nematoda, Onchocercidae) em Tropidurus hispidus Spix 1825 (Sauria, Tropiduridae). Um macho e uma fêmea de O. petersi foram coletados no músculo ileofibularis direito desse lagarto. Este é o primeiro relato deste hospedeiro para Oswaldofilaria spp. e também a descrição de um novo hospedeiro para O. petersi.