Species determination of Brazilian mammals implicated in the epidemiology of rabies based on the control region of mitochondrial DNA

Identification of animals that are decomposing or have been run over or burnt and cannot be visually identified is a problem in the surveillance and control of infectious diseases. Many of these animals are wild and represent a valuable source of information for epidemiologic research as they may be carriers of an infectious agent. This article discusses the results obtained using a method for identifying mammals genetically by sequencing their mitochondrial DNA control region. Fourteen species were analyzed and identified. These included the main reservoirs and transmitters of rabies virus, namely, canids, chiroptera and primates. The results prove that this method of genetic identification is both efficient and simple and that it can be used in the surveillance of infectious diseases which includes mammals in their epidemiologic cycle, such as rabies.

Dinâmica populacional: variação sazonal dos grupos funcionais fitoplanctônicos em reservatórios brasileiros (Billings e Guarapiranga, São Paulo)

A comunidade fitoplanctônica pode funcionar como sensor das variações do ambiente aquático respondendo rapidamente as essas alterações. Em sistemas aquáticos continentais é comum a coexistência de espécies que possuem as mesmas necessidades ecológicas e apresentam as mesmas tolerâncias ambientais, tais grupos de espécies fitoplanctônicas são denominados grupos funcionais. O uso de grupos funcionais fitoplanctônicos para avaliar tais alterações tem se mostrado muito útil e eficaz. Assim, o objetivo do estudo foi avaliar a ocorrência de grupos funcionais fitoplanctônicos em dois reservatórios (Billings e Guarapiranga) que suprem de água milhões de pessoas na Região Metropolitana de São Paulo, Sudeste do Brasil. As amostras foram coletadas mensalmente na superfície da coluna d'água e foram analisadas as variáveis físicas, químicas e biológicas (análises qualitativa e quantitativa do fitoplâncton). Os maiores valores de biovolume (mm3.L-1) das espécies descritoras e grupos funcionais foram representados por Anabaena circinalis (H1), Microcystis aeruginosa (LM/M) e Mougeotia sp. (T) no Reservatório Guarapiranga e por Cylindrospermopsis raciborskii (SN), Microcystis aeruginosa e M. panniformis (LM/M), Planktothrix agardhii e P. cf. clathrata (S1) no Reservatório Billings. Os principais fatores ambientais que interferiram na dinâmica do fitoplâncton foram: temperatura da água, zona eufótica, turbidez, condutividade, pH, oxigênio dissolvido, nitrato e fósforo total

Clonal relationship among atypical enteropathogenic Escherichia coli strains isolated from different animal species and humans

Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.

Detection of metallo-'beta'-lactamases-encoding genes in environmental isolates of Aeromonas hydrophila and Aeromonas jandaei

Aims: To determine the prevalence and expression of metallo-beta-lactamases (MBL)-encoding genes in Aeromonas species recovered from natural water reservoirs in southeastern Brazil. Methods and Results: Eighty-seven Aeromonas isolates belonging to Aeromonas hydrophila (n = 41) and Aer. jandaei (n = 46) species were tested for MBL production by the combined disk test using imipenem and meropenem disks as substrates and EDTA or thioglycolic acid as inhibitors. The presence of MBL genes was investigated by PCR and sequencing using new consensus primer pairs designed in this study. The cphA gene was found in 97.6% and 100% of Aer. hydrophila and Aer. jandaei isolates, respectively, whereas the acquired MBL genes bla(IMP), bla(VIM) and bla(SPM-1) were not detected. On the other hand, production of MBL activity was detectable in 87.8% and 10.9% of the cphA-positive Aer. hydrophila and Aer. jandaei isolates respectively. Conclusions: Our results indicate that cphA seems to be intrinsic in the environmental isolates of Aer. hydrophila and Aer. jandaei in southeastern Brazil, although, based on the combined disk test, not all of them are apparently able to express the enzymatic activity. Significance and Impact of the Study: These data confirm the presence of MBL-producing Aeromonas species in natural water reservoirs. Risk of water-borne diseases owing to domestic and industrial uses of freshwater should be re-examined from the increase of bacterial resistance point of view

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera hydroeletric plant, São Paulo, Brazil

A febre amarela (FA) é doença infecciosa aguda de origem viral transmitida por mosquitos. No ciclo silvestre, o vírus é mantido por meio da infecção de macacos e da transmissão transovariana nos vetores. A vigilância sobre populações de primatas não humanos torna-se necessária para detectar a circulação viral, quando ainda está restrito a epizootias, e para determinar sua presença em regiões indenes ou de transição para a doença. Padronizou-se a técnica ELISA (Enzyme Linked Immunosorbent Assay) para determinar a prevalência de anticorpos da classe IgG contra o vírus da FA em soros de bugios (Alouatta caraya) da região do reservatório da Usina Hidrelétrica de Porto Primavera, SP. Foram testados soros de 570 macacos sendo que nenhuma amostra mostrou-se reativa para a presença de anticorpos contra o vírus da FA. Os resultados são coerentes com a epidemiologia da FA na região. Mesmo sendo área de transição, não se conhece, até o momento, ocorrência de epizootia ou surto de FA em humanos e investigações entomológicas não apontaram a presença de vetores para esta arbovirose. A técnica mostrou-se sensível, rápida e útil à vigilância epidemiológica como instrumento de busca ativa permitindo desencadear ações preventivas, como vacinação, antes mesmo do surgimento de epizootias

Transmission potential, skin inflammatory response, and parasitism of symptomatic and asymptomatic dogs with visceral leishmaniasis

Background: Visceral leishmaniasis in Brazil is caused by the protozoan Leishmania (Leishmania) chagasi and it is transmitted by sandfly of the genus Lutzomyia. Dogs are an important domestic reservoir, and control of the transmission of visceral leishmaniasis (VL) to humans includes the elimination of infected dogs. However, though dogs are considered to be an important element in the transmission cycle of Leishmania, the identification of infected dogs representing an immediate risk for transmission has not been properly evaluated. Since it is not possible to treat infected dogs, they are sacrificed when a diagnosis of VL is established, a measure that is difficult to accomplish in highly endemic areas. In such areas, parameters that allow for easy identification of reservoirs that represents an immediate risk for transmission is of great importance for the control of VL transmission. In this study we aimed to identify clinical parameters, reinforced by pathological parameters that characterize dogs with potential to transmit the parasite to the vector. Results: The major clinical manifestations of visceral leishmaniasis in dogs from an endemic area were onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. The transmission potential of these dogs was assessed by xenodiagnosis using Lutzomyia longipalpis. Six of nine symptomatic dogs were infective to Lutzomyia longipalpis while none of the five asymptomatic dogs were infective to the sandfly. Leishmania amastigotes were present in the skin of all clinically symptomatic dogs, but absent in asymptomatic dogs. Higher parasite loads were observed in the ear and ungueal region, and lower in abdomen. The inflammatory infiltrate was more intense in the ears and ungueal regions of both symptomatic and asymptomatic dogs. In clinically affected dogs in which few or none Leishmania amastigotes were observed, the inflammatory infiltrate was constituted mainly of lymphocytes and macrophages. When many parasites were present, the infiltrate was also comprised of lymphocytes and macrophages, as well as a larger quantity of polymorphonuclear neutrophils (PMNs). Conclusion: Dogs that represent an immediate risk for transmission of Leishmania in endemic areas present clinical manifestations that include onicogriphosis, skin lesions, conjunctivitis, lymphadenopathy, and weight loss. Lymphadenopathy in particular was a positive clinical hallmark since it was closely related to the positive xenodiagnosis.

Hantavirus Pulmonary Syndrome, Central Plateau, Southeastern, and Southern Brazil

Hantavirus pulmonary syndrome (HPS) is an increasing health problem in Brazil because of encroachment of sprawling urban, agricultural, and cattle-raising areas into habitats of subfamily Sigmodontinae rodents, which serve as hantavirus reservoirs. From 1993 through June 2007, a total of 884 cases of HIPS were reported in Brazil (case-fatality rate 39%). To better understand this emerging disease, we collected 89 human serum samples and 68 rodent lung samples containing antibodies to hantavirus from a 2,500-km-wide area in Brazil. RNA was isolated from human samples and rodent lung tissues and subjected to reverse transcription-PCR. Partial sequences of nucleocapsid protein and glycoprotein genes from 22 human and 16 rodent sources indicated only Araraquara virus and Juquitiba virus lineages. The case-fatality rate of HPS was higher in the area with Araraquara virus. This virus, which may be the most virulent hantavirus in Brazil, was associated with areas that have had greater anthropogenic changes.

PREVALENCE OF ANTIBODIES TO TRYPANOSOMA CRUZI, LEISHMANIA INFANTUM, ENCEPHALITOZOON CUNICULI, SARCOCYSTIS NEURONA, AND NEOSPORA CANINUM IN CAPYBARA, HYDROCHOERUS HYDROCHAERIS, FROM SAO PAULO STATE, BRAZIL

Little is known about the importance of capybara. Hydrochoerus hydrochaeris, as reservoirs for parasites of zoonotic or veterinary importance. Sera from 63 capybaras, from 6 counties in the state of Sao Paulo, Brazil, were examined for antibodies to Trypanosoma cruel, Leishmania infantum, Encephalitozoon cuniculi. Sarcacystis neurona, and Neospora caninum using an indirect immunofluorescent antibody test. Five (8%) of the 63 capybaras had antibodies to T cruzi epimastigotes. None of the samples from capybara reacted positively with L. infantum promastigotes or with spores of E. cuniculi. Two (3%) of the serum samples were positive for antibodies to S. neurona merozoites, and 2 (3%) of the serum samples were positive for antibodies to N. caninum tachyzoites. A serum sample from 1 capybara was positive for antibodies to both T cruzi and N. caninum. None of the remaining 62 samples reacted with more than 1 parasite.

Decoherence-free evolution of time-dependent superposition states of two-level systems and thermal effects

In this paper we detail some results advanced in a recent letter [Prado et al., Phys. Rev. Lett. 102, 073008 (2009).] showing how to engineer reservoirs for two-level systems at absolute zero by means of a time-dependent master equation leading to a nonstationary superposition equilibrium state. We also present a general recipe showing how to build nonadiabatic coherent evolutions of a fermionic system interacting with a bosonic mode and investigate the influence of thermal reservoirs at finite temperature on the fidelity of the protected superposition state. Our analytical results are supported by numerical analysis of the full Hamiltonian model.

Nonadiabatic Coherent Evolution of Two-Level Systems under Spontaneous Decay

In this Letter we extend current perspectives in engineering reservoirs by producing a time-dependent master equation leading to a nonstationary superposition equilibrium state that can be nonadiabatically controlled by the system-reservoir parameters. Working with an ion trapped inside a nonideal cavity, we first engineer effective interactions, which allow us to achieve two classes of decoherence-free evolution of superpositions of the ground and excited ionic levels: those with a time-dependent azimuthal or polar angle. As an application, we generalize the purpose of an earlier study [Phys. Rev. Lett. 96, 150403 (2006)], showing how to observe the geometric phases acquired by the protected nonstationary states even under nonadiabatic evolution.

State protection under collective damping and diffusion

In this paper we provide a recipe for state protection in a network of oscillators under collective damping and diffusion. Our strategy is to manipulate the network topology, i.e., the way the oscillators are coupled together, the strength of their couplings, and their natural frequencies, in order to create a relaxation-diffusion-free channel. This protected channel defines a decoherence-free subspace (DFS) for nonzero-temperature reservoirs. Our development also furnishes an alternative approach to build up DFSs that offers two advantages over the conventional method: it enables the derivation of all the network-protected states at once, and also reveals, through the network normal modes, the mechanism behind the emergence of these protected domains.

Non-Markovian dynamics of quantum discord

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.

Ionic mobility of the solvated proton and acid-base titration in a four-compartment capillary electrophoresis system

Although H(+) and OH(-) are the most common ions in aqueous media, they are not usually observable in capillary electrophoresis (CE) experiments, because of the extensive use of buffer solutions as the background electrolyte. In the present work, we introduce CE equipment designed to allow the determination of such ions in a similar fashion as any other ion. Basically, it consists of a four-compartment piece of equipment for electrolysis-separated experiments (D. P. de Jesus et at, Anal. Chem., 2005, 77, 607). In such a system, the ends of the capillary are placed in two reservoirs, which are connected to two other reservoirs through electrolyte-filled tubes. The electrodes of the high-voltage power source are positioned in these reservoirs. Thus, the electrolysis products are kept away from the inputs of the capillary. The detection was provided by two capacitively coupled contactless conductivity detectors (CD), each one positioned about 11 cm from the end of the capillary. Two applications were demonstrated: titration-like procedures for nanolitre samples and mobility measurements. Strong and weak acids (pK(a) < 5), pure or mixtures, could be titrated. The analytical curve is linear from 50 mu M up to 10 mM of total dissociable hydrogen (r = 0.99899 for n =10) in 10-nL samples. By including D(2)O in the running electrolyte, we could demonstrate how to measure the mixed proton/deuteron mobility. When H(2)O/D(2)O (9 : 1 v/v) was used as the solvent, the mobility was 289.6 +/- 0.5 x 10(-5) cm(2) V(-1) s(-1). Due to the fast conversion of the species, this value is related to the overall behaviour of all isotopologues and isotopomers of the Zundel and Eigen structures, as well as the Stokesian mobility of proton and deuteron. The effect of neutral (o-phenanthroline) and negatively charged (chloroacetate) bases and aprotic solvent (DMSO) over the H(+) mobility was also demonstrated.

Intra and interannual variability in the Madeira River water chemistry and sediment load

Concentrations of cations (Na(+), Ca(2+), Mg(2+), K(+), NH(4) (+)), anions (HCO(3) (-), Cl(-), NO(3) (-), SO(4) (2-), PO(4) (3-)) and suspended sediments in the Madeira River water were determined near the city of Porto Velho (RO), in order to assess variation in water chemistry from 2004 to 2007. Calcium and bicarbonate were the dominant cation and anion, respectively. Significant seasonal differences were found, with highest concentrations occurring during the dry season, as expected from the drainage of Andean carbonate-rich substratum. Interannual variations were also observed, but became significant only when annual average discharge was 25% less than normal. Under this atypical discharge condition, bicarbonate was replaced by sulfate, and higher suspended sediment concentrations and loads were also observed. Compared to previously published studies, it appears that no significant changes in water chemistry have occurred during the last 20-30 years, although differences in approaches and sampling designs among this and previous studies may not allow detection of modest changes. The calculated suspended sediment load reported here is close to the values presented elsewhere, reinforcing the relative importance of this river as a sediment supplier for the Amazon Basin. Seasonality has a significant control on the chemistry of Madeira River waters, and severe decrease in discharge due to anthropogenic changes, such as construction of reservoirs or the occurrence of drier years-a plausible consequence of global climate change-may lead to modification in the chemical composition as well in the sediment deliver to the Amazon River.

Morphological and molecular characterization of cyanobacteria from a Brazilian facultative wastewater stabilization pond and evaluation of microcystin production

The cyanobacterial population in the Cajati waste stabilization pond system (WSP) from Sao Paulo State, Brazil was assessed by cell isolation and direct microscope counting techniques. Ten strains, belonging to five genera (Synechococcus, Merismopedia, Leptolyngbya, Limnothrix, and Nostoc), were isolated and identified by morphological and molecular analyses. Morphological identification of the isolated strains was congruent with their phylogenetic analyses based on 16S rDNA gene sequences. Six cyanobacterial genera (Synechocystis, Aphanocapsa, Merismopedia, Lyngbya, Phormidium, and Pseudanabaena) were identified by direct microscope inspection. Both techniques were complementary, since, of the six genera identified by direct microscopic inspection, only Merismopedia was isolated, and the four other isolated genera were not detected by direct inspection. Direct microscope counting of preserved cells showed that cyanobacteria were the dominant members (> 90%) of the phytoplankton community during both periods evaluated (summer and autumn). ELISA tests specific for hepatotoxicmicrocystins gave positive results for six strains (Synechococcus CENA108, Merismopedia CENA106, Leptolyngbya CENA103, Leptolyngbya CENA112, Limnothrix CENA109, and Limnothrix CENA110), and for wastewater samples collected from raw influent (3.70 mu g microcystins/l) and treated effluent (3.74 mu g microcystins/l) in summer. Our findings indicate that toxic cyanobacteria in WSP systems are of concern, since the treated effluent containing cyanotoxins will be discharged into rivers, irrigation channels, estuaries, or reservoirs, and can affect human and animal health.