Hantaviruses as emergent zoonoses

Hantaviruses belong to the Bunyaviridae family, which consists of vector-borne viruses. These viruses can provoke two infection types: hemorrhagic fever with renal syndrome (HFRS) - which occurs in the Old World - and hantavirus cardiopulmonary syndrome (HCPS) - an emergent zoonosis that can be found in many countries of the western hemisphere. Rodents are hantavirus reservoirs and each species seems to host a different virus type. Humans acquire the infection by inhaling contaminated aerosol particles eliminated by infected animals. The factors involved in the emergence of hantavirus infections in the human population include ecological modifications and changes in human activities. The most important risk factor is contact between man and rodents, as a result of agricultural, forestry or military activities. Rodent control remains the primary strategy for preventing hantavirus diseases, including via health education and hygienic habits.

Occurrence and risk factors associated with canine leptospirosis

Leptospirosis is a globally distributed emerging zoonosis. Dogs are commonly affected and although other serovars can cause canine leptospirosis, Leptospira interrogans serovar Canicola is primary found in these animals. A retrospective study was conducted using a database of 1195 dogs tested for Leptospira infection from 2003 to 2010 at the Laboratory of Zoonosis Diagnosis at the Veterinary Hospital of São Paulo State University (UNESP) in Botucatu, São Paulo state, Brazil. The seroprevalence of infected dogs was 20.08% (240/1195), and the most prevalent serovars were Canicola (6.7%), Copenhageni (5.0%), Icterohaemorrhagiae (2.9%), Autumnalis (2.9%), Pyrogenes (2.8%), Pomona (2.0%), Hardjo (2.0%), Australis (1.8%), Bratislava (1.6%), Cynopteri (1.4%), Grippotyphosa (1.3%) and Djasiman (1.0%). By univariate analysis, the variables age and breed were not statistically related to the infection, while gender and season were. The effects of gender were also noticeable related to serovars Australis, Canicola and Hardjo. In multivariate analysis, the level of significance (p-value) of season was suppressed by gender, indicating possible collinearity between those two variables.

Road-killed wild animals: a preservation problem useful for eco-epidemiological studies of pathogens

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

Cell-mediated immune response to Leishmania chagasi experimental infection of BALB/c immunosuppressed mice

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

Detection of Toxoplasma gondii in the milk of experimentally infected Wistar female rats

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

Rabies virus in a pregnant naturally infected southern yellow bat (Lasiurus ega)

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

Interactions between environment, wild animals and human leptospirosis

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

Brazilian spotted fever: A reemergent zoonosis

Brazilian spotted fever is caused by the bacterium Rickettsia rickettsii, which is the most pathogenic species of the spotted-fever rickettsiae group and is transmitted by the bite of infected ticks. Amblyomma cajennense is the most important tick species involved in the cycle of this zoonosis in Brazil as it presents low host specificity, great number of natural reservoirs and wide geographic distribution. It was first described in the state of São Paulo in 1929 and later in Rio de Janeiro, Minas Gerais and Bahia. The number of cases decreased in the 1940's with the development of new plague control techniques and antibiotics. In the last decades, the number of new cases has increased. The current review aimed at reporting some of the epidemiological and public health aspects of this reemergent disease with new foci, mainly in the southeastern region of Brazil.

Performance of IFAT, ELISA, direct parasitological examination and PCR on lymph node aspirates for canine visceral leishmaniasis diagnosis

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

Antibacterial activity of propolis collected in different regions of Brazil

The aim of this study was to investigate the antibacterial activity of propolis samples from Goiás, Paraná and São Paulo States, Brazil, and their flavonoids content. Ethanolic extracts of propolis (EEP) were prepared (30g of propolis in 70% ethanol), and the microorganisms Staphylococcus aureus and Escherichia coli were tested. The methodology employed was agar diffusion using filter paper discs. Ampicillin and tetracycline were used as controls. Antibacterial activity was determined by the reading of inhibition zone diameters (mm) after 24 hours incubation at 37°C. Results demonstrated that EEP inhibited the growth of Staphylococcus aureus but not that of Escherichia coli. Tetracycline and ampicillin showed an efficient action against both bacteria. Flavonoids content was variable, depending on the propolis sample. According to the results, it may be concluded that EEP showed effective action against Gram-positive bacteria, independently on their geographic origin, and a positive correlation between antibacterial activity and flavonoids content.

Association between handling stress in the corral and rabies antibody titers in selenium-supplemented cattle

This study determined the correlation between serum cortisol levels and rabies antibody titers in cattle primo-vaccinated against rabies and supplemented with dietary selenium (Se). Sixty Nelore male calves (10 to 12 months old) received daily and individual dietary supplementation with 0, 3.6, 5.4 and 6.4 mg Se (groups Gc, G(3.6), G(5.4) and G(6.4), respectively). The animals were vaccinated against rabies (day 0) and subjected to handling stress in the corral for 120 days. Blood sampling procedures were performed on days 0, 15, 30, 60, 90 and 120. Cortisol levels increased until day 90, but had dropped significantly by day 120 (P < 0.01). Rabies antibody titers on days 30 and 90 were similar among Se-supplemented groups; in the control group, rabies antibodies decreased significantly from day 30 to 60, and 90 to 120. Serum cortisol levels and antibody titers were not correlated in most of the groups or blood sampling days. A positive correlation among these variables was found only in G(6.4) on days 60 (R = 0.513; P = 0.05) and 120 (R = 0.644; P = 0.009). In conclusion, repeated handling in the corral stresses cattle, but without compromising rabies humoral immune response.

Propolis effect on streptozotocin-induced diabetic rats

Propolis is one of the hive products that has been used extensively in folk medicine, due to its several biological and pharmacological properties. Besides, propolis-containing products have been intensely marketed by the pharmaceutical industry and health-food stores. This work was carried out in order to investigate whether propolis treatment could revert the metabolic alterations of streptozotocin-induced diabetic rats. Animals were kept in metabolic cages and diabetes was induced by a single dose of streptozotocin (35 mg/kg, IV). After a week, rats with glycemia higher than 230 mg/dL were divided into two groups and treated with ethanolic extract of propolis (10 and 90 mg/kg, PO) for seven days. Glycemia and free fatty acids were determined, as well as food and water intake, body weight and urine volume were registered weekly. Data showed no significant differences in the analyzed variables. Based on these results, one may conclude that propolis had no effects after diabetes establishment, in our conditions assays. Further assays with different concentrations of propolis and periods of administration should be carried out in order to evaluate its therapeutic potential in this disease.

Antimicrobial activity of propolis and essential oils and synergism between these natural products

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

Microdilution procedure for antifungal susceptibility testing of Paracoccidioides brasiliensis to amphotericin B and itraconazole

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

Ballast water: a review of the impact on the world public health

Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilancia Sanitaria - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human infections caused by BW exists but none is completely safe and efficient.