Use of the MCNPX to calculate the neutron spectra around the GE-PETtrace 8 cyclotron of the CDTN/CNEN, Brazil.

The Monte Carlo code MCNPX was used to calculate the neutron spectra in 4 points around the targets of the CDTN/CNEN cyclotron, Belo Horizonte, Brazil, during the production of the (18)FDG. Simulated data were compared with experimental data obtained with a Bonner multisphere spectrometry system (BSS) using TLD-600 and TLD-700 and the unfolding codes BUNKIUT, BUMS and NSDUAZ. In general, simulated spectra disagreed with those obtained by experimental means by a factor as high as 14. Measurements performed with a doserate meter in other 3 more shielded points, showed also an overestimation of the ambient dose equivalent rate by a factor as high as 20 in comparison with simulated results. Results are not conclusive and a more refined study is necessary. However, neutron emission rate of the source-term of radiation must be investigated and an special caution must be taken in the experimental measurements, by discriminating of the target selected for the irradiations and utilizing a matrix response suitable for the passive detectors (e.g. TLD) utilized in the experiments, instead of a matrix response (e.g. UTA4) developed for scintillation detectors.

Risk factors associated with seroprevalence of Neospora caninum in dogs from urban and rural areas of milk and coffee production in Minas Gerais state, Brazil.

This study was conducted to determine the seroprevalence of anti-Neospora caninum antibodies and to investigate the risk factors related to seroprevalence in dogs from urban and rural areas with distinct economic activities (milk and coffee production) in Minas Gerais state, Brazil. For this purpose, blood samples from 703 dogs were collected and questionnaires addressing epidemiological aspects were completed by dog-owners. The sera were analysed for anti-N. caninum antibodies by indirect fluorescent antibody tests (IFAT ≥ 1:50). Association between epidemiological aspects and seropositivity in dogs was evaluated with multivariate logistic regression models. A total of 80 (11·4%) dogs tested positive for N. caninum. In the multivariate logistic regression models, dogs aged >4 years, dogs used as guard dogs, dogs that spontaneously hunt, and history of bovine abortion were found to be greater risk factors for canine N. caninum infection. When we considered only dogs from rural areas, an association with seroprevalence was seen for milk farms, dogs not fed with commercial food, dogs that hunt, and dogs used as guard dogs.

Eucalyptus growth promotion by endophytic Bacillus spp.

Clonal eucalyptus plantings have increased in recent years; however, some clones with high production characteristics have vegetative propagation problems because of weak root and aerial development. Endophytic microorganisms live inside healthy plants without causing any damage to their hosts and can be beneficial, acting as plant growth promoters. We isolated endophytic bacteria from eucalyptus plants and evaluated their potential in plant growth promotion of clonal plantlets of Eucalyptus urophylla x E. grandis, known as the hybrid, E. urograndis. Eighteen isolates of E. urograndis, clone 4622, were tested for plant growth promotion using the same clone. These isolates were also evaluated for indole acetic acid production and their potential for nitrogen fixation and phosphate solubilization. The isolates were identified by partial sequencing of 16S rRNA. Bacillus subtilis was the most prevalent species. Several Bacillus species, including B. licheniformis and B. subtilis, were found for the first time as endophytes of eucalyptus. Bacillus sp strain EUCB 10 significantly increased the growth of the root and aerial parts of eucalyptus plantlets under greenhouse conditions, during the summer and winter seasons.

Use of a TLD-based multisphere spectrometry system to measure the neutron spectra around a not-self-shielded PET cyclotron: Preliminary results.

In the present work, we utilized the BSS system with TLD-600 and TLD-700 to measure the neutron spectra around the GE-PETtrace 8 cyclotron of the Development Centre of Nuclear Technology (CDTN/CNEN) in Belo Horizonte, Brazil. The cyclotron is capable of accelerating protons up to 16.5 MeV, to production of fluorine-18. Four points inside the bunker of the cyclotron were studied. Two points in front of the primary radiation beam and other two opposed to the primary radiation beam. The measurements were unfolded with the BUMS and the NSDUAZ computer codes. The dosimetric quantities obtained were in agreement with the other published data and were coherent with the expected from theoretical estimates obtained from source term informed by the manufacturer of the cyclotron.

A quantitative TaqMan PCR assay for the detection of Mycoplasma suis.

AIM: To develop a TaqMan probe-based, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma suis in the blood of pigs. METHODS AND RESULTS: Primers and probes specific to Myc. suis 16S rRNA gene were designed. The qPCR assay's specificity, detection limit, intra- and inter-assay variability were evaluated and its performance was compared with a Myc. suis conventional PCR assay (cPCR). Blood of two experimentally infected pigs, 40 Indiana pigs, 40 Brazilian sows and 28 peccaries were tested. The assay detected as few as ten copies of Myc. suis plasmids and was 100-fold more sensitive than the cPCR. No cross-reactivity with nontarget pig mycoplasmas was observed. An average of 1·62 × 10(11) and 2·75 × 10(8) target copies ml(-1) of blood were detected in the acutely and chronically infected pigs, respectively. Three (7·5%) pigs and 32 (80·0%) sows were positive while all peccaries were negative for Myc. suis. CONCLUSION: The developed qPCR assay is highly sensitive and specific for Myc. suis detection and quantification. SIGNIFICANCE AND IMPACT OF THE STUDY: TaqMan qPCR is an accurate and quick test for detection of Myc. suis infected pigs, which can be used on varied instrumentation platforms.

Intraspecific sequence variation in 16S rRNA gene of Ureaplasma diversum isolates.

Ureaplasma diversum infection in bulls may result in seminal vesiculitis, balanoposthitis and alterations in spermatozoids. In cows, it can cause placentitis, fetal alveolitis, abortion and the birth of weak calves. U. diversum ATCC 49782 (serogroups A), ATCC 49783 (serogroup C) and 34 field isolates were used for this study. These microorganisms were submitted to Polymerase Chain Reaction for 16S gene sequence determination using Taq High Fidelity and the products were purified and bi-directionally sequenced. Using the sequence obtained, a fragment containing four hypervariable regions was selected and nucleotide polymorphisms were identified based on their position within the 16S rRNA gene. Forty-four single nucleotide polymorphisms (SNP) were detected. The genotypic variability of the 16S rRNA gene of U. diversum isolates shows that the taxonomy classification of these organisms is likely much more complex than previously described and that 16S rRNA gene sequencing may be used to suggest an epidemiologic pattern of different origin strains.

Detection of Bartonella spp. in neotropical felids and evaluation of risk factors and hematological abnormalities associated with infection.

Although antibodies to Bartonella henselae have been described in all neotropical felid species, DNA has been detected in only one species, Leopardus wiedii. The aim of this study was to determine whether DNA of Bartonella spp. could be detected in blood of other captive neotropical felids and evaluate risk factors and hematological findings associated with infection. Blood samples were collected from 57 small felids, including 1 Leopardus geoffroyi, 17 L. wiedii, 22 Leopardus tigrinus, 14 Leopardus pardalis, and 3 Puma yagouaroundi; 10 blood samples from Panthera onca were retrieved from blood banks. Complete blood counts were performed on blood samples from small felids, while all samples were evaluated by PCR. DNA extraction was confirmed by amplification of the cat GAPDH gene. Bartonella spp. were assessed by amplifying a fragment of their 16S-23S rRNA intergenic spacer region; PCR products were purified and sequenced. For the small neotropical felids, risk factors [origin (wild-caught or zoo-born), gender, felid species, and flea exposure] were evaluated using exact multiple logistic regression. Hematological findings (anemia, polycythemia/hyperproteinemia, leukocytosis and leukopenia) were tested for association with infection using Fisher's exact test. The 635bp product amplified from 10 samples (10/67=14.92%) was identified as B. henselae by sequencing. Small neotropical felid males were more likely to be positive than females (95% CI=0.00-0.451, p=0.0028), however other analyzed variables were not considered risk factors (p>0.05). Hematological abnormalities were not associated with infection (p>0.05). This is the first report documenting B. henselae detection by PCR in several species of neotropical felids.

Survey of owned feline and canine populations in apartments from a neighbourhood in Curitiba, Brazil.

Animal population estimates are essential for public health services to ensure the success of zoonoses control programmes. Canine and feline populations vary among different regions mainly because of local human income status and type of human residence. Accordingly, the present study estimated the pet population size living in apartments of a vertical neighbourhood in Curitiba, Brazil. We chose a neighbourhood with a predominance of apartment buildings. All apartment buildings were visited, and questionnaires were completed by doormen or residents. Data were obtained from 120 of 173 apartment buildings. Survey questions included the number of apartments, residents, dogs and cats. Two thousand nine hundred and sixty six apartments with a total of 7429 residents were surveyed. The number of dogs and cats was 569 and 86 respectively. Thus, the human:dog and human:cat ratios were 13.05:1 and 86.38:1. These ratios were higher than those observed in other neighbourhoods in Curitiba. The present study indicates that the number of pets from apartments may be different from houses, and different among distinct areas within the same city.

Exploratory study of Mycoplasma suis (Eperythrozoon suis) on four commercial pig farms in southern Brazil.

Mycoplasma suis (Eperythrozoon suis) was detected by PCR and Southern blot in 186 pigs (121 sows, 61 piglets and four boars) on four farms in southern Brazil. DNA was extracted from blood samples and a 16S rRNA gene fragment of M suis was amplified by PCR; Southern blot analysis was then performed on all the samples. Twenty-two of the sows (18.2 per cent) were positive by PCR, and 40 (33.1 per cent) were positive by Southern blot; only one piglet and one boar were positive. The packed cell volume and total plasma protein of the pigs and their PCR and Southern blot results were not significantly different on the four farms, but higher proportions of the pigs were positive by Southern blot than by PCR (P<0.05). The packed cell volume and total plasma protein concentrations of the M suis positive and negative sows were not significantly different.

Ocorrencia de Giardia spp. em bezerros leiteiros no Brasil / Occurrence of Giardi ssp. in dairy calves in Brazil

Fecal samples were collected from 50 female Holstein calves (1-90 days old) from a commercial dairy cattle farm located in Lavras, Minas Gerais, Brazil and examined for presence of Giardia cysts using the zinc sulfate flotation method. A total of 120 samples were collected from March 1999 to April 2000, and fecal consistency (normal or diarrheic) was noted prior to the examination for Giardia cysts. Giardia ssp. cysts were found in 11 (9 per cent) of the 120 faecal samples of calves co-infected with Eimeria spp., in calves from 19 to 58 days of age (38 +/- 19). In 82 per cent (9/11) calves assessed for mixed infections with Cryptosporidium spp. and Giardia, oocysts of Cryptosporidium were found in three out of four diarrheic calves (75 per cent) positive for Giardia. Giardia cysts (n=30) sized 13-16 x 10-12µm (mean of 15 x 11µm). They appeared to belong to the morphological group of G. intestinallis according to the size and morphological characteristic of the cysts. This is the first detection of Giardia spp. in calves in Brazil. Considering that Giardia has the potential to cause clinical disease in calves and that organisms infecting humans and domestic ruminants are morphologically and antigenically similar, and calves can shed Giardia cysts potentially infective for humans, the parasite in calves may be of major epidemiological significance, and suggests that naturally infected calves may be reservoirs of Giardia infections for man

Epidemiological aspects of Babesia equi in horses in Minas Gerais, Brazil.

The prevalence of Babesia equi in two climatic regions of Minas Gerais state was determined using the indirect fluorescent antibody test (IFAT) with blood samples obtained from horses in two slaughterhouses. Of 399 samples, 241 (60.4%) showed a positive reaction. Anti-B. equi antibody was detected in every county studied, the prevalence being 59.7% for horses in the area where the temperature rises above 18 degrees C in winter and 61.4% in the area where it remains below 18 degrees C, indicating that climatic variation has no substantial effect on the prevalence of the infection in Brazil. Blood samples collected from all 95 horses on a ranch in the state of Minas Gerais, Brazil, on which clinical babesiosis had never been reported, were subjected to the IFAT Anti-B. equi antibodies were detected in horses of all ages, but with a significantly lower prevalence in animals less than 6 months old.

Anemia and intestinal parasitic infections in primary school students in Aracaju, Sergipe, Brazil.

Anemia is estimated to affect half the school-age children and adolescents in developing countries. The main causes are parasitic infections, malaria, and low iron intake. This study aimed to describe the prevalence of anemia, parasitic infections, and nutritional status of children attending public primary schools in Aracaju, Northeast Brazil. Of 360 students, 26.7% were anemic, and prevalence was higher in children under 8 and over 15 years of age. Overall prevalence of intestinal parasites was 42%, with Ascaris lumbricoides (28.7%), Trichuris trichiura (15.6%), and hookworm (1. 7%) most frequently found. There was an association between parasitic infections and poor sanitary conditions, but there was no association between anemia and presence of intestinal parasites. Height-for-age Z scores were lower than the NCHS standard, and prevalence of stunting was 5.4%. Although intestinal parasites were not associated with anemia, children with parasites had lower nutritional indices (weight- and height-for-age Z scores) than those without parasites.

Encephalitozoon-like microsporidia in the ticks Amblyomma cajennense and Anocentor nitens (Acari: Ixodidae).

A Encephalitozoon-like microsporidia was found in epithelial cells of the midgut and the salivary glands of Amblyomma cajennense (F.) and Anocentor nitens (Neumann) that had fed on rabbits. Ultrastructural studies demonstrated that all stages of the life cycle of the parasite occur in parasitophorous vacuoles and contain only 1 nucleus. The sporonts detach from the limiting membrane of the vacuole and divide by binary fission to produce the sporoblasts, each presenting a thickened electron-dense wall, and a primordium of a polar filament. Each spore contained a single nucleus, an electron-dense and rough exospore, an electron-lucent and thick endospore, and 5 coils of the polar tubule.

Consumo e digestibilidade aparente do resíduo de cultura de milho tratado ou näo tratado com hidróxido de sódio e suplementado com uréia para ruminantes / Intake and digestibility of corn crop residue, treated or non treated with sodium hidroxide and suplemented with urea for ruminants

O presente trabalho teve como objetivo determinar o valor nutritivo do resíduo de cultura do milho (RCM) tratado quimicamente com álcali forte ((TII) para ruminantes, ou do RCM sem tratamento químico (TI), ambos suplementados com uréia, mediante ensaios de digestibilidade aparente com ovinos. Os testes de digestibilidade mostraram valores de 55,53 por cento e 60,34 por cento nos coeficientes de digestibilidade da matéria seca em TI e TII, respectivamente. O consumo de energia digestível foi de 124,27kcal/dia/kg elevado a 0,75 sobrescrito no TI e de 148,13kcal/dia/kg 0,75 sobrescrito no TII

Dinâmica da fermentaçäo ruminal do resíduo de cultura de milho tratado ou näo tratado com hidróxido de sódio e suplementado com uréia / Dynamic of ruminal fermentation of corn crop residue, treated or non treated with sodium hydroxide and supplemented with urea

Este trabalho teve como objetivo estudar a dinâmica da fermentaçäo ruminal do resíduo de cultura de milho (RCM), após tratamento com álcali forte (TII), ou do RCM sem tratamento químico (TI), ambos suplementados com uréia, fornecido a ovinos como único alimento. A taxa de fermentaçäo da matéria seca, utilizando-se sacos de náilon, foi igual para as duas dietas. A concentraçäo de ácidos graxos voláteis no líquido ruminal em funçäo do tempo de fermentaçäo também foi semelhante nos dois tratamentos. No TII, a concentraçäo de N-NH3 subscrito foi inferior à do TI

Sporogony and experimental transmission of Babesia equi by Boophilus microplus.

The development of Babesia equi in salivary glands of adult female Boophilus microplus was observed under a light microscope using semithin sections stained with toluidine blue. Engorged nymphs were obtained from splenectomized foals experimentally infected with B. equi. As adults, they were then fed on rabbits for 5 days and the salivary glands of manually collected individuals were removed at intervals of 24 h. Sporozoites were found in type III granular acini cells between the 2nd and 5th days following feeding on the rabbits. Sporoblasts and sporozoites were observed in the same or adjacent acini cells in all the glands examined. The formation of the sporozoites occurred following the multiple division of the sporoblasts through a process of radial budding from the periphery of bodies resulting from multiple fission. Sporozoites were detected in smears of adult males stained with Giemsa, between the 2nd and 5th days following feeding by the ticks. Adults of B. microplus, fed during the nymphal phase on foals with patent parasitemia, transmitted sporozoites of B. equi to a splenectomized foal. The role of B. microplus in the transmission and epidemiology of B. equi is discussed.

Ultrastructure of sporogony in Babesia equi in salivary glands of adult female Boophilus microplus ticks.

The development of Babesia equi was studied in the salivary glands of adult female ticks, Boophilus microplus, using a transmission electron microscope (TEM). Engorged nymphs were obtained from splenectomized foals experimentally infected with B. equi and fed in the adult phase for 5 days on rabbits. Sporogony in B. equi involves the development of sporoblasts and sporozoites, which form from finger-like projections on the surface and through radial budding. Mature sporozoites (2.0 x 1.1 microns), typically pyriform, showed a polar ring, rhoptries, micronemes, nuclei, and mitochondria, and a high concentration of free ribosomes were observed from the 2nd day of the ticks, feeding on the rabbits. In general, sporogony of B. equi in the salivary glands of B. microplus showed similarities to the development of this parasite in species of Hyalomma, although with some significant differences in the sporozoite's dimensions. The results of this study indicate that B. equi is capable of multiplying in the salivary glands of adult female B. microplus, forming sporozoites with specialized organelles characteristic of the invasive form, and suggest that B. microplus can act as a natural vector of B. equi in endemic areas where there is no other probable source of infection or where it is the only tick species present on horses.

Ultrastructure of Anaplasma marginale with an inclusion appendage, isolated in Minas Gerais State, Brazil.

This is the first report on the occurrence and isolation of a strain of Anaplasma marginale with an inclusion appendage in Brazil. The inclusion appendage presented longitudinal electron-dense striations and did not originate directly from the body of the rickettsia but from an electron-dense complex located at the junction of the inclusion membrane and inclusion appendage. The inclusion appendage remained in the host cell after the Anaplasma inclusion appeared to be leaving the red blood cell. Other ultrastructures of this rickettsia are described and its epidemiological importance is discussed.