Multilocus sequence types of invasive Corynebacterium diphtheriae isolated in the Rio de Janeiro urban area, Brazil.

Invasive infections caused by Corynebacterium diphtheriae in vaccinated and non-vaccinated individuals have been reported increasingly. In this study we used multilocus sequence typing (MLST) to study genetic relationships between six invasive strains of this bacterium isolated solely in the urban area of Rio de Janeiro, Brazil, during a 10-year period. Of note, all the strains rendered negative results in PCR reactions for the tox gene, and four strains presented an atypical sucrose-fermenting ability. Five strains represented new sequence types. MLST results did not support the hypothesis that invasive (sucrose-positive) strains of C. diphtheriae are part of a single clonal complex. Instead, one of the main findings of the study was that such strains can be normally found in clonal complexes with strains related to non-invasive disease. Comparative analyses with C. diphtheriae isolated in different countries provided further information on the geographical circulation of some sequence types.

First Report of Frogeye Leaf Spot of Soybean Caused by Cercospora sojina Race 11 in Virginia.

Frogeye leaf spot of soybean (FLS) (Glycine max (L.) Merr.), caused by Cercospora sojina Hara, was first detected in Virginia in 1942 (1). During the 2008 growing season, a FLS survey was conducted in soybean fields in Virginia. This was the first FLS race survey conducted in Virginia. Typical frogeye leaf spot symptoms, as reported by Phillips (4), were observed on soybean leaves in Westmoreland County. During 2008, Westmoreland County planted 7,365 ha of soybean. Symptomatic leaves were collected from V06-1891, V06-1365, V05-4394, V04-8405, and Hutcheson cultivars from plants in growth stages R5 to R6. Leaves were placed in a moist chamber for 24 h at 21°C with 12-h light to induce sporulation. C. sojina was only recovered from V06-1365. Conidia were removed from the leaves, placed into V8 juice agar amended with rifampicin (10 mg ml-1) and ampicillin (0.25 g liter-1) and incubated at 21°C with 12-h light. Cultures with dark pigmentation and presence of conidia were observed after 3 weeks. Conidia matched the description of C. sojina (4). Conidia had three to nine septa, were hyaline, elongate to fusiform, and measured 3 to 6 × 25 to 40 µm. Race identification was conducted using the set of differentials reported by Mian et al. (3). Spores for inoculation were produced on soybean stem lima bean agar (SSLBA) media. Tencentimeter-diameter pots, each containing four plants, were used. The test was conducted twice in a complete randomized design with three replications. Seedlings were inoculated at the V3 growth stage with a spore suspension of 6 × 104 spores/ml. Control plants were sprayed with sterile distilled water. Plants were placed in a greenhouse bench humidity chamber at 21°C for 72 h. Disease rating was conducted 14 days after inoculation. Since the resistance to FLS is known to be controlled by single dominant genes, the FLS was scored as a qualitative trait (i.e., resistant versus susceptible) as previously done by Mian et al. (2). Plants that showed numerous, large, spreading lesions were classified as susceptible and each plant was given a score of 1. Plants that showed no lesions or only small lesions or flecks were classified as resistant and each plant was given a score of 0. Control plants remained healthy. On the basis of the reaction response of the isolate on the set of differentials and comparison with the proposed race designations of Mian et al. (3), the isolate was classified as race 11. Race 11 shows compatible reaction (susceptibility) on the soybean cv. Lincoln, which is the source of Rcs1 resistance gene, and incompatible reactions (resistance) on cvs. Peking, Davis, and Kent. The latter two cultivars are sources of the Rcs3 and Rcs2 genes, respectively. Successful development of soybean cultivars with FLS resistance not only depends on knowledge of the presence of resistance genes, but also on the understanding of the pathogen population structure. To our knowledge this is the first report of C. sojina race 11 from soybean in Virginia. Resistance to this race is conditioned by Rcs2, Rcs3, and the single dominant gene in Peking (3). We recommend use of Rcs3 and Rcs2 genes and the single dominant gene in Peking for resistance to FLS in Virginia. References: (1) S. B. Fenn. Plant Dis. Rep. 26:383, 1942. (2) M. A. R. Mian et al. Crop Sci. 39:1687, 1999. (3) M. A. R. Mian et al. Crop Sci. 48:14, 2008. (4) D. V. Phillips. Page 20 in: Compendium of Soybean Diseases. 4th ed. The American Phytopathological Society. St. Paul, MN, 1999.

Prevalence of bipolar disorder in the general population: a Reappraisal Study of the Netherlands Mental Health Survey and Incidence Study.

OBJECTIVE: The Netherlands Mental Health Survey and Incidence Study (NEMESIS) is a Dutch population study using a fully structured interview (Composite International Diagnostic Interview, CIDI), administered by trained interviewers. Based on all three assessments of NEMESIS, 2.4% of the respondents were identified with lifetime bipolar disorder (DSM-III-R). The primary aim of the study was to estimate the prevalence of bipolar disorder in the same population based on a semistructured interview administered by clinicians. METHOD: Seventy-four persons identified with a lifetime CIDI/DSM-III-R bipolar disorder and 40 persons with a major depressive disorder (MDD) were reinterviewed with the Structured Clinical Interview for DSM (SCID). RESULTS: Based on the SCID, 30 of 74 respondents with a CIDI/DSM-III-R bipolar disorder and eight of 40 respondents with MDD met DSM-IV criteria for bipolar disorder or cyclothymia, corresponding with an adjusted lifetime prevalence in these groups of 1% (95% CI: 0.7-1.3%) and 4.2% (95% CI: 1.6-6.9%) respectively. CONCLUSION: Compared with the SCID, the CIDI on the one hand overdiagnoses bipolar disorder but on the other hand underdiagnoses bipolar disorder.

Evaluation of the antiviral activity against Junin virus of macrocyclic trichothecenes produced by the hypocrealean epibiont of Baccharis coridifolia.

Four macrocyclic trichothecenes, roridin A, roridin E, verrucarin A and verrucarin J, produced by the hypocrealean epibiont of Baccharis coridifolia, were evaluated for their inhibitory activity against the arenavirus Junin (JUNV), the etiological agent of Argentine hemorrhagic fever. The trichothecenes achieved a dose-dependent inhibition of JUNV multiplication at concentrations not affecting cell viability. The 50 % inhibitory concentration (IC50) values determined by a virus yield inhibition assay were in the range 1.2 - 4.9 ng/ml. The most active compound was verrucarin J which reduced JUNV yield more than 2 log units and had a similar effect against the arenavirus Tacaribe. The trichothecenes lacked virucidal effects on JUNV virions. From time of addition and removal experiments, it can be concluded that verrucarin J inhibited a late stage in the replicative cycle of JUNV, after 5 h of adsorption.

[Epidemiological data on the plague in Madagascar]. / Actualités épidémiologiques de la peste à Madagascar.

The first case of plague was introduced in Madagascar in 1898 in the east coast by way of boat from India. In 1921, plague reach the highlands and a large epidemic over the next twenty years. Until the beginning of the 80's, only of few case were identified, notified mostly in rural setting. However gradually it has re-emerged as a public health problem. Urban plague is located in the city of Antananarivo (resurgence in 1978 after 28 years of apparent silence) and in Mahajanga port (resurgence in 1991 after 63 years of silence). The reactivation of the Plague National Control Program from 1994 will allow better surveillance. The aim of this analysis is to update the epidemiological data on human plague in Madagascar based on reported cases obtained from the Central Lab of the Pasteur Institute of Madagascar from 1980 to 2001 (16,928 suspected cases of which 3,500 are likely positives or confirmed positives). The Plague season runs from October to March on the central highlands and July to November on the north-western coast. Sex-ratio male/female is 1.3/1, and the age-group of 5 to 25 years is more affected. The case fatality rate was 40% in the beginning of the 1980's, and decreased to 20% by the end of the 1990's. The percentage of case with pulmonary plague decrease from 15% to less than 5%. However, geographical extension is demonstrated: 4 districts in 1980, 30 districts in 1999 and 21 districts in 2001. In 2002, the diffusion of a new rapid test (reagent strip) in the primary health centres (CSB) in 42 endemic districts may help to decrease the morbidity and the letality due to plague and improve its control at the national level.

Actualités épidémiologiques de la peste à Madagascar

La peste est entrée à Madagascar en 1898, à partir du port de Toamasina, suite à l'escale d'un bâteau venant d'Inde. En 1921, elle arrive à Antananarivo et s'étend sur les Hautes Terres Centrales en y provoquant des épidémies sans précédent pendant près de 20 ans. Jusqu'au début des années 1980, elle a persisté à bas bruit surtout en milieu rural, avant de connaître une reviviscence au point de constituer un problème de santé publique de nos jours. La peste urbaine existe surtout dans la ville d'Antananarivo (réémergence en 1978 après 28 ans de silence apparent) et dans le port de Mahajanga (réémergence en 1991 après 63 ans de silence apparent). La re-dynamisation du programme national de lutte contre la peste, à partir de 1994, a permis une meilleure surveillance de la maladie. Cette analyse a pour objectif une actualisation des données épidémiologiques de la peste humaine à Madagascar, à partir des cas déclarés (16 928 cas suspects dont 3 500 confirmés ou probables) obtenus au Laboratoire Central à l'Institut Pasteur de Madagascar de 1980 à 2001. La saison pesteuse sur les hautes terres se situe d'octobre à mars et celle de la ville de Mahajanga de juillet à novembre. Le sex-ratio homme/femme est de 1,3/1, la tranche d'âge la plus touchée est celle des sujets âgés de 5 à 25 ans. Le taux de létalité de 40% au début des années 1980 a diminué à 20% vers la fin des années 1990, le pourcentage de formes pulmonaires est passé de 15% à moins de 5%, indiquant une amélioration de la prise en charge des cas. Par contre, on a assisté à une extension géographique de l'endémie pesteuse dans le pays : 4 districts confirmés en 1980, un pic de 30 districts en 1999 et 21 districts en 2001. En 2002, la diffusion d'un nouveau test de diagnostic rapide de la peste (bandelettes), dans les centres de santé de base des 42 districts endémiques, devrait contribuer à diminuer la morbidité et la létalité due à la peste, et améliorer sa surveillance au niveau national

[The plague at the Tsenabe Isotry market in Antananarivo: a complex epidemiologic situation]. / La peste dans le marché Tsenabe Isotry à Antananarivo: une situation épidémiologique complexe.

The transmission of Yersinia pestis is intense among rats in the wholesale market Tsenabe Isotry in the capital Antananarivo (anti-F1 sero-prevalence 80%, flea index 8.4 for a cut-off risk index of > 1). However, the number of plague-suspected (not laboratory confirmed) human cases has only been 3 in this district during a four years period from 1995 to 1999. A seroepidemiological survey among the market vendors was undertaken in June 1999 to test the hypothesis that the low incidence of human plague is due to acquired immunity. In addition, surveillance of the rat and the flea populations in the market was carried out. Only 3 (3.2%) of 95 screened vendors were anti-F1 IgG positive, whereas the markers of plague transmission among rodents and fleas were still high. This result suggests that the low incidence of human plague was not due to acquired immunity but to other factors such as the limited contact between humans and the rat fleas because of the abundance of rats, the absence of epizootic due to the resistance of rats in the capital and a particular behaviour of the predominant rat Rattus norvegicus.

La peste dans le marché Tsenabe Isotry à Antananarivo : une situation épidémiologique complexe

La surveillance de la peste murine en 1995 dans le marché de gros Tsenabe Isotry à Antananrivo a montré une circulation intense du bacille pesteux (80% de rats séropositifs) et un index cheopis (8,4) supérieur au seuil classique de risque épidémique (>1). Pourtant, le nombre de malades suspects déclarés dans ce quartier est très faible (3 cas suspects sans confirmation de 1995 à 1999). Dans le but de vérifier si la faible incidence de la peste humaine pouvait être due à l'acquisition d'une immunité, une enquête séroépidémiologique a été menée auprès des marchands en juin 1999 associée à l'analyse des données de la surveillance des rongeurs entre 1998 ­ 1999. La séroprévalence des porteurs d'anticorps anti-F1 est de 3,2% (3/95 marchands), alors que les marqueurs de la transmission de la peste chez les rongeurs et les puces continuent d'être très élevés. Ces résultats suggèrent que l'incidence de la peste parmi les marchands n'est pas liée à une immunité acquise, mais probablement à d'autres facteurs : le faible contact entre l'homme et les puces de rat en raison de l'abondance des rats, l'absence d'épizootie murine due à la résistance des rats de la capitale et le comportement du rongeur prédominant Rattus norvegicus moins commensal que R. rattus

Production of Cry11A and Cry11Ba toxins in Bacillus sphaericus confers toxicity towards Aedes aegypti and resistant Culex populations.

Cry11A from Bacillus thuringiensis subsp. israelensis and Cry11Ba from Bacillus thuringiensis subsp. jegathesan were introduced, separately and in combination, into the chromosome of Bacillus sphaericus 2297 by in vivo recombination. Two loci on the B. sphaericus chromosome were chosen as target sites for recombination: the binary toxin locus and the gene encoding the 36-kDa protease that may be responsible for the cleavage of the Mtx protein. Disruption of the protease gene did not increase the larvicidal activity of the recombinant strain against Aedes aegypti and Culex pipiens. Synthesis of the Cry11A and Cry11Ba toxins made the recombinant strains toxic to A. aegypti larvae to which the parental strain was not toxic. The strain containing Cry11Ba was more toxic than strains containing the added Cry11A or both Cry11A and Cry11Ba. The production of the two toxins together with the binary toxin did not significantly increase the toxicity of the recombinant strain to susceptible C. pipiens larvae. However, the production of Cry11A and/or Cry11Ba partially overcame the resistance of C. pipiens SPHAE and Culex quinquefasciatus GeoR to B. sphaericus strain 2297.

Contribution of the 65-kilodalton protein encoded by the cloned gene cry19A to the mosquitocidal activity of Bacillus thuringiensis subsp. jegathesan.

Two new crystal protein genes, cry19A and orf2, isolated from Bacillus thuringiensis subsp. jegathesan were cloned and characterized. The cry19A gene encodes a 74.7-kDa protein, and the orf2 gene encodes a 60-kDa protein. Cry19A contains the five conserved blocks present in most B. thuringiensis delta-endotoxins. The ORF2 amino acid sequence is similar to that of the carboxy terminus of Cry4 proteins. The cry 19A gene was expressed independently or in combination with orf2 in a crystal-negative B. thuringiensis host. The proteins accumulated as inclusions. Purified inclusions containing either Cry19A alone or Cry19A and ORF2 together were toxic to Anopheles stephensi and Culex pipiens mosquito larvae. They were more toxic to C. pipiens than to A. stephensi. However, inclusions containing Cry19A and ORF2 together were more toxic than inclusions of Cry19A alone but less toxic than the wild-type inclusions of B. thuringiensis subsp. jegathesan.

Distribution of the insertion element IS240 among Bacillus thuringiensis strains.

The presence of IS240 was investigated in 69 Bacillus thuringiensis (Bt) strains including strains from serotype H1 to H45 and additional strains with known Dipteran larvae toxicity. Restriction digests of total DNA and PCR products obtained with a single 16-bases primer corresponding to the IS240 inverted repeated sequence were hybridized with the IS240A element. The results indicate that 67% of the Bt strains tested, including all known mosquitocidal strains, possess at least one IS240-related element. PCR experiments indicate that IS240 represents a family of insertion sequences with several variants.

Cloning and expression of a novel toxin gene from Bacillus thuringiensis subsp. jegathesan encoding a highly mosquitocidal protein.

A gene, designated cry11B, encoding a 81,293-Da crystal protein of Bacillus thuringiensis subsp. jegathesan was cloned by using a gene-specific oligonucleotide probe. The sequence of the Cry11B protein, as deduced from the sequence of the cry11B gene, contains large regions of similarity with the Cry11A toxin (previously CryIVD) from B. thuringiensis subsp. israelensis. The Cry11B protein was immunologically related to both Cry11A and Cry4A proteins. The cry11B gene was expressed in a nontoxic strain of B. thuringiensis, in which Cry11B was produced in large amounts during sporulation and accumulated as inclusions. Purified Cry11B inclusions were highly toxic for mosquito larvae of the species Aedes aegypti, Culex pipiens, and Anopheles stephensi. The activity of Cry11B toxin was higher than that of Cry11A and similar to that of the native crystals from B. thuringiensis subsp. jegathesan, which contain at least seven polypeptides.