RESUMO
Wild animals infected with Paracoccidioides brasiliensis represent important indicators of this fungal agent presence in the environment. The detection of this pathogen in road-killed wild animals has shown to be a key strategy for eco-epidemiological surveillance of paracoccidioidomycosis (PCM), helping to map hot spots for human infection. Molecular detection of P. brasiliensis in wild animals from PCM outbreak areas has not been performed so far. The authors investigated the presence of P. brasiliensis through nested-PCR in tissue samples obtained from road-killed animals collected nearby a human PCM outbreak spot, Rio de Janeiro state, Brazil and border areas. Eighteen species of mammals were analyzed: Dasypus novemcinctus (nine-banded armadillo, n = 6), Cerdocyon thous (crab-eating fox, n = 4), Coendou spinosus (hairy dwarf porcupine, n = 2), Lontra longicaudis (Neotropical river otter, n = 1), Procyon cancrivorus (crab-eating raccoon, n = 1), Galactis cuja (lesser grison, n = 1), Tamandua tetradactyla (collared anteater, n = 1), Cuniculus paca (paca, n = 1), and Bradypus variegatus (brown-throated three-toed sloth, n = 1). Specific P. brasiliensis sequences were detected in the liver, spleen, and lymph node samples from 4/6 (66.7%) D. novemcinctus, reinforcing the importance of these animals on Paracoccidioides ecology. Moreover, lymph nodes samples from two C. thous, as well as lung samples from the C. paca were also positive. A literature review of Paracoccidioides spp. in vertebrates in Brazil indicates C. thous and C. paca as new hosts for the fungal pathogen P. brasiliensis.
Assuntos
Canidae/microbiologia , Cuniculidae/microbiologia , Mamíferos/microbiologia , Paracoccidioides/isolamento & purificação , Animais , Animais Selvagens/microbiologia , Brasil , DNA Fúngico/química , DNA Fúngico/metabolismo , Feminino , Fígado/microbiologia , Linfonodos/microbiologia , Masculino , Paracoccidioides/genética , Análise de Sequência de DNA , Baço/microbiologiaRESUMO
Melanin is a Sporothrix virulence factor that can inhibit the innate immune functions of macrophages such as phagocytosis and killing. However, no data on melanin's influence on antigen presentation by macrophages are available. In this study, we used conidia, yeasts, and melanin ghosts (MGs) from a black Sporothrix globosa strain (MEL+) and its ultraviolet-induced albino mutant (MEL-), to study the influence of melanin on expression of molecules involved in antigen presentation by mouse macrophages (MHC class II, CD80, CD86), as well as on levels of transcription factors regulating their expression (CIITA and promoters I, III, and IV). A murine infection model was used to assess the virulence of both strains and differences in expression of MHC class II and CD80/86 in vivo. MHC class II, CD86 CIITA, and PIV expressions were lower in macrophages infected with MEL+ than in macrophages infected with MEL- conidia, while CD80 expression was similar. No statistical difference in gene expression was observed between macrophages infected by MEL+ and MEL- yeasts. Infection by MGs alone had no clear effect on expression of antigen presentation-associated molecules. Mice infected with MEL+ S. globosa had significantly higher fungal burdens in the lung, liver, spleen, kidney, and testicle compared with mice infected with MEL- S. globosa 21 days post-infection. MHC class II expression changes in the animal study were similar to those observed in the in vitro experiment. Our results indicate that S. globosa melanin can inhibit expression of antigen presentation-associated molecules during both the early and late stages of infection, representing a new mechanism to evade host immunity and to enhance dissemination. Further investigations of melanin's impact on adaptive immunity will be helpful in understanding this fungal virulence factor.
Assuntos
Macrófagos Peritoneais/imunologia , Melaninas/imunologia , Sporothrix/imunologia , Esporotricose/microbiologia , Animais , Apresentação de Antígeno , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Interações Hospedeiro-Patógeno , Humanos , Fígado/microbiologia , Pulmão/microbiologia , Macrófagos Peritoneais/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Sporothrix/genética , Esporotricose/genética , Esporotricose/imunologiaRESUMO
BACKGROUND: Leptospirosis is an important anthropozoonosis. The study investigated the presence of anti-Leptospira antibodies and detection of Leptospira spp DNA in the urine as well as the biochemical profile in Neotropical wild primates living in a forest reserve from Southeast São Paulo State, Brazil. METHODS: Blood samples were obtained from 50 adult tufted capuchin monkeys (Cebus apella nigritus). Urine samples were obtained only from male primates. The screening for antibodies against Leptospira spp was evaluated by microscopic agglutination test (MAT). Leptospira DNA in the urine was evaluated by polymerase chain reaction (PCR) considering the target gene LipL32. Biochemical profile was evaluated by using a spectrophotometer. RESULTS: The MAT results included 39 (78%) serum reactive animals with the proportions of 28/39 males and 11/39 females. The most frequent reactive serogroups were Icterohemorrhagiae, Canicola, and Autumnalis. All urine samples were negative for leptospiral DNA. There were no significant differences between sexes for aspartate aminotransferase (AST) and alkaline phosphatase values, but alanine aminotransferase (ALT), creatinine, glucose, and urea were significantly higher in males. CONCLUSIONS: Tufted capuchin monkeys were sera reactive against leptospirosis. Prevalence was similar for the 2 sexes. Leptospiral DNA was not detected in the urine of sera reactive primates tested by the MAT method. ALT, creatinine, glucose, and urea values were higher in male animals.
Assuntos
Anticorpos Antibacterianos/sangue , Cebinae , DNA Bacteriano/urina , Leptospira/isolamento & purificação , Leptospirose/veterinária , Doenças dos Macacos/epidemiologia , Animais , Brasil/epidemiologia , Rim/microbiologia , Rim/patologia , Leptospirose/epidemiologia , Leptospirose/microbiologia , Fígado/microbiologia , Fígado/patologia , Masculino , Doenças dos Macacos/microbiologia , SapajusRESUMO
Salmonella Gallinarum (SG) is an avian-restricted pathogen that causes fowl typhoid in poultry. Although it has been reported frequently over many decades in poultry flocks worldwide, the microorganism is more commonly associated with poultry in developing countries, particularly those with high ambient temperatures, where the acute form of the disease results in considerable economic losses. A more detailed investigation of environmental factors that affect the course of disease may assist in identifying effective prevention and control measures. Heat stress is known to impair the immunological response to a variety of pathogens and clearly may be an important contributory factor in the prevalence of disease in countries with warm or hot climates. Thus, the objective of the present study was to evaluate the effects of heat stress on chickens infected with SG. For this, light and semi-heavy commercial laying hens were distributed randomly within four groups as follows: infected and non-infected groups in rooms held at ambient temperature, and infected and non-infected groups under heat stress. Clinical signs, egg production, and mortality were recorded daily. Bacteriological counts in liver and spleen samples were estimated at 2, 5, 7, and 14 days post-infection. The results showed that both SG infection and heat stress had similar effects on egg production and a synergistic effect of the two stressors was observed. The data show an interaction between disease and heat stress which could point towards environmental and biosecurity approaches to resolving the possible 30% fall in production observed in such countries.
Assuntos
Galinhas/fisiologia , Resposta ao Choque Térmico , Doenças das Aves Domésticas/fisiopatologia , Salmonelose Animal/fisiopatologia , Salmonella enterica/fisiologia , Febre Tifoide/veterinária , Animais , Galinhas/microbiologia , Ovos , Feminino , Fígado/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Baço/microbiologia , Febre Tifoide/microbiologia , Febre Tifoide/fisiopatologiaRESUMO
OBJECTIVES: The study was designed to determine the presence of Helicobacter genus and three species of H. pylori, H. bilis, and H. canis, in the duodenum, ileum, colon, and liver of stray cats. Moreover, the histopathological and immunohistochemical analyses have been performed. METHODS: Samples were taken from the duodenum, ileum, colon, and liver of 30 cats for molecular and histopathological evaluations. Polymerase chain reaction was carried out for the detection of the Helicobacter genus in the mentioned samples. Then, species-specific primers were used in Helicobacter-positive samples. RESULTS: Helicobacter genus prevalence rates in the duodenum, ileum, colon, and liver samples were 50%, 60%, 50%, and 43.3%, respectively. Helicobacter pylori, H. canis, and H. bilis were isolated from at least one tissue of 18 (60%), 13 (43.3%), and 8 (26.7%) of the cats, respectively. Immunohistochemical findings confirmed the presence of bacteria in the intestinal crypt or the mucosal layer of duodenum, ileum, colon, and hepatic sinusoids. CONCLUSION: In the present study, the concurrent infection of duodenum and liver was noticeable. Furthermore, the high prevalence of H. pylori in cats, as a well-known human pathogen, should be considered. High incidence of Helicobacter in gut and liver of Ahvaz stray cats is noticeable. According to the zoonotic importance of Helicobacter, more studies in the field of treatment and prevention are highly recommended.
Assuntos
Animais Selvagens/microbiologia , Infecções por Helicobacter/veterinária , Helicobacter/classificação , Intestinos/microbiologia , Fígado/microbiologia , Animais , Gatos/microbiologia , DNA Bacteriano/genética , Helicobacter/isolamento & purificação , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/patologia , Imuno-Histoquímica , Irã (Geográfico)/epidemiologia , Prevalência , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND/OBJECTIVES: Vaccination is the most important tool for controlling brucellosis, but currently there is no vaccine available for canine brucellosis, which is a zoonotic disease of worldwide distribution caused by Brucella canis. This study aimed to evaluate protection and immune response induced by Brucella ovis ΔabcBA (BoΔabcBA) encapsulated with alginate against the challenge with Brucella canis in mice and to assess the safety of this strain for dogs. METHODS: Intracellular growth of the vaccine strain BoΔabcBA was assessed in canine and ovine macrophages. Protection induced by BoΔabcBA against virulent Brucella canis was evaluated in the mouse model. Safety of the vaccine strain BoΔabcBA was assessed in experimentally inoculated dogs. RESULTS: Wild type B. ovis and B. canis had similar internalization and intracellular multiplication profiles in both canine and ovine macrophages. The BoΔabcBA strain had an attenuated phenotype in both canine and ovine macrophages. Immunization of BALB/c mice with alginate-encapsulated BoΔabcBA (108 CFU) induced lymphocyte proliferation, production of IL-10 and IFN-γ, and protected against experimental challenge with B. canis. Dogs immunized with alginate-encapsulated BoΔabcBA (109 CFU) seroconverted, and had no hematologic, biochemical or clinical changes. Furthermore, BoΔabcBA was not detected by isolation or PCR performed using blood, semen, urine samples or vaginal swabs at any time point over the course of this study. BoΔabcBA was isolated from lymph nodes near to the site of inoculation in two dogs at 22 weeks post immunization. CONCLUSION: Encapsulated BoΔabcBA protected mice against experimental B. canis infection, and it is safe for dogs. Therefore, B. ovis ΔabcBA has potential as a vaccine candidate for canine brucellosis prevention.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Vacina contra Brucelose/imunologia , Brucella ovis/genética , Brucelose/prevenção & controle , Doenças do Cão/prevenção & controle , Alginatos/química , Animais , Formação de Anticorpos , Brucella canis/patogenicidade , Brucella ovis/imunologia , Brucella ovis/isolamento & purificação , Brucelose/microbiologia , Brucelose/patologia , Doenças do Cão/microbiologia , Doenças do Cão/patologia , Cães , Feminino , Imunização , Fígado/microbiologia , Fígado/fisiologia , Linfócitos/citologia , Linfócitos/imunologia , Linfócitos/metabolismo , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mutação , OvinosRESUMO
Probiotics form a promising strategy to maintain intestinal health. Milks fermented with probiotic strains, such as the Lactobacillus paracasei ST11, are largely commercialized in Brazil and form a low-cost alternative to probiotic pharmaceutical formulations. In this study, we assessed the probiotic effects of milk fermented by L. paracasei ST11 (administered through fermented milk) in a Salmonella typhimurium infection model in BALB/c mice. We observed in this murine model that the applied probiotic conferred protective effects against S. typhimurium infection, since its administration reduced mortality, weight loss, translocation to target organs (liver and spleen) and ileum injury. Moreover, a reduction in the mRNA expression of pro-inflammatory cytokines such as IFN-γ, IL-6, TNF-α and IL-17 in animals that received the probiotic before challenge was observed. Additionally, the ileum microbiota was better preserved in these animals. The present study highlights a multifactorial protective aspect of this commercial probiotic strain against a common gastrointestinal pathogen.
Assuntos
Produtos Fermentados do Leite , Resistência à Doença/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Lacticaseibacillus paracasei/fisiologia , Probióticos/farmacologia , Infecções por Salmonella/prevenção & controle , Animais , Peso Corporal/efeitos dos fármacos , Dieta , Resistência à Doença/genética , Resistência à Doença/imunologia , Regulação da Expressão Gênica/imunologia , Íleo/efeitos dos fármacos , Íleo/imunologia , Íleo/microbiologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/mortalidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/patogenicidade , Baço/efeitos dos fármacos , Baço/imunologia , Baço/microbiologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Bats can harbor zoonotic pathogens, but their status as reservoir hosts for Leptospira bacteria is unclear. During 2015-2017, kidneys from 47 of 173 bats captured in Grenada, West Indies, tested PCR-positive for Leptospira. Sequence analysis of the Leptospira rpoB gene from 31 of the positive samples showed 87-91% similarity to known Leptospira species. Pairwise and phylogenetic analysis of sequences indicate that bats from Grenada harbor as many as eight undescribed Leptospira genotypes that are most similar to known pathogenic Leptospira, including known zoonotic serovars. Warthin-Starry staining revealed leptospiral organisms colonizing the renal tubules in 70% of the PCR-positive bats examined. Mild inflammatory lesions in liver and kidney observed in some bats were not significantly correlated with renal Leptospira PCR-positivity. Our findings suggest that Grenada bats are asymptomatically infected with novel and diverse Leptospira genotypes phylogenetically related to known pathogenic strains, supporting the hypothesis that bats may be reservoirs for zoonotic Leptospira.
Assuntos
Quirópteros/microbiologia , Reservatórios de Doenças/microbiologia , Leptospira/classificação , Leptospirose/veterinária , Animais , Reservatórios de Doenças/veterinária , Granada , Rim/microbiologia , Rim/patologia , Leptospira/genética , Leptospira/isolamento & purificação , Leptospirose/microbiologia , Leptospirose/patologia , Fígado/microbiologia , Fígado/patologia , FilogeniaRESUMO
Fluctuations in ambient temperature along with the presence of pathogenic microorganisms can induce important cellular changes that alter the homeostasis of ectothermic fish. The aim of this study was to evaluate how sudden or gradual changes in environmental temperature together with the administration of Piscirickettsia salmonis modulate the transcription of genes involved in cellular stress response in the liver of Eleginops maclovinus. Fish were subjected to the following experimental conditions in duplicate: C- 12 °C: Injection only with culture medium, C+ 12 °C: Injection with P. salmonis, AM 18 °C: Injection only with culture medium under acclimation at 18 °C, AB 18 °C: Injection with P. salmonis under acclimation at 18 °C, SM 18 °C: Injection only with culture medium and thermal shock at 18 °C and SB 18 °C: Injection with P. salmonis and thermal shock at 18 °C and sampling at 4-, 8-, 12-, 16- and 20-day post injection (dpi). The genes implied in the heat shock response (HSP70, HSC70, HSP90, and GRP78), apoptosis pathway (BAX and SMAC/Diablo), ubiquitination (E2, E3, ubiquitin, and CHIP), and 26 proteasome complex (PSMB7, PSMC1, and PSMA2) showed expression profiles dependent on time and type of injection applied. All the genes greatly increased their expression levels at day 16 and showed moderate increases at day 20, except for PSMA2 which showed a higher increase between 4- and 12-day post challenges. Our results suggest that the changes observed at the final days of the experiment are due to temperature more than P. salmonis.
Assuntos
Doenças dos Peixes/microbiologia , Fígado/microbiologia , Piscirickettsia/patogenicidade , Estresse Fisiológico/fisiologia , Temperatura , Animais , Peixes , Fígado/metabolismo , Perciformes , Piscirickettsia/metabolismoRESUMO
The effect of dietary aflatoxin B1 (AFB1) and Salmonella Enteritidis infection on intestinal permeability was investigated. Two hundred 1-day-old male Ross 308 broiler chickens were randomly divided into 4 treatments of 5 replicates each (10 birds per replicate), which were fed ad libitum for 3 weeks with the following treatments: control, chickens fed an AFB1-free diet; AF, chickens fed an AFB1-contaminated diet at 470 ng/g; SE, chickens fed an AFB1-free diet and challenged with 108 cfu of S. Enteritidis per bird at 18 days old; AF + SE, chickens fed an AFB1-contaminated diet and challenged with 108 cfu of S. Enteritidis per bird at 18 days old. At day 21 of age, chicks received an oral gavage dose of fluorescein isothiocyanate dextran (FITC-dextran) to evaluate gastrointestinal leakage. Blood and intestinal samples were collected to evaluate serum biochemistry and total intestinal IgA secretion, respectively. Liver tissues were aseptically collected to assess bacterial invasiveness and for histomorphological studies. The results showed that chickens receiving AFB1 presented a significant increment (up to 2.4-fold) in serum FITC-dextran concentration (p < 0.05). Nevertheless, S. Enteritidis infection had no additional effect on gastrointestinal leakage. Furthermore, the ingestion of AFB1 had no impact on the invasive potential of S. Enteritidis. These results suggest that moderate-dose AFB1 adversely affects intestinal barrier function resulting in increased gut permeability in broiler chickens.