ABSTRACT
Staphylococcus pseudintermedius is a zoonotic pathogen responsible for several infectious diseases in pet animals, yet its pathogenic potential is not fully understood. Thus, this study aims to unravel the virulence profile of S. pseudintermedius from canine origin. Methicillin-resistant (MRSP) and methicillin-susceptible (MSSP) strains were isolated from different infection sites and their genotypic and phenotypic features were compared to determine the clinical implications of MRSP and MSSP strains. Bacterial identification was performed using MALDI-TOF and 16S-rDNA sequencing. In addition, we used multilocus sequence typing (MLST) for strains' sequence type (ST) determination and phylogenetic relationship. The strains were screened for toxin genes, including cytotoxins (lukS, lukF), exfoliative toxin (siet), enterotoxins (sea, seb, sec, secCanine, sel, sem, and seq) and toxic shock syndrome toxin (tst-1). In vitro phenotypic analyses assessing antimicrobial susceptibility profile, biofilm formation ability, and expression of extracellular matrix components were performed. The investigated S. pseudintermedius strains belong to 17 unique ST, most of which were classified as ST71. MSSP and MRSP strains shared siet, lukS, and lukF virulence markers. Our findings showed that some MSSP strains also harbored sel, seq, and sem enterotoxin genes, suggesting a more diverse virulence profile. All MRSP strains and 77% of MSSP strains were classified as multidrug resistant (MDR). Moreover, all investigated S. pseudintermedius strains showed strong biofilm formation ability. In summary, our findings highlight the wide spread of highly virulent and drug-resistant zoonotic S. pseudintermedius strains, being a potential concern for One Health issues.
Subject(s)
Dog Diseases , Staphylococcal Infections , Dogs , Animals , Methicillin/pharmacology , Methicillin Resistance/genetics , Staphylococcal Infections/veterinary , Staphylococcal Infections/microbiology , Multilocus Sequence Typing , Phylogeny , Dog Diseases/microbiology , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity TestsABSTRACT
ABSTRACT: Visceral leishmaniasis (VL) is a zoonotic disease with a canine urban reservoir in South America. Dogs from an endemic area within Brazil, which were naturally infected with Leishmania infantum, and those presenting severe clinical (SC), mild, or no clinical (MNC) disease, were evaluated. Parasite load, histopathology, and cytokine and iNOS mRNA expressions were assessed in the spleen and liver in order to determine the potential markers for disease susceptibility or resistance. As a result, dogs with both SC and MNC had high parasite loads; IFN-γ was the most expressive cytokine in both organs, along with IL-6 and IL-4 being detected in the spleen and liver, and IL-10 only in liver. The hepatic tissue presented higher medians for IFN-γ and IL-10, and was the main organ to produce cytokines with hepatic IL-10 suggesting a regulatory follow up. Granulomas were detected in both organs; however, when absent in spleen, they were associated with elevated IL-6 levels, thus highlighting the anti-inflammatory role of IL-6. Microscopic lesions in the spleen were predominantly characterized by an extensively disorganized white pulp and splenic response was suggested as sub optimized. Parasite load, tissue damage, and immunological response may vary in the dogs with similar clinical symptoms, which may not be a good parameter for assessing the animal's susceptibility to VL.
RESUMO: A Leishmaniose visceral (LV) é uma doença zoonótica com reservatório canino na América do Sul. Cães oriundos de área endemica brasileira, naturalmente infectados por Leishmania infantum, apresentando doença clínica severa (CS) ou doença branda ou ausente (BA) foram avaliados. Carga parasitária, histopatologia e expressão de mRNA de citocinas e iNOS foram analisados em baço e fígado, buscando determinar possíveis marcadores de susceptibilidade ou resistência à doença. Como principais resultados, tanto cães CS como BA apresentaram alta carga parsitária. IFN-γ foi a citocina mais expressiva em ambos os órgãos, sendo IL-6 e IL-4 também detectadas em baço e fígado e IL-10 em fígado. No tecido hepático foram encontradas as maiores medianas de IFN-γ e IL-10, sendo o fígado o principal órgão produtor de citocinas, com IL-10 sugerindo acompanhamento regulatório. Granulomas foram detectados em ambos os órgãos. Quando de sua ausência no baço, essa foi associada à elevação dos níveis de IL-6, salientando o papel anti-inflamatório dessa citocina. Alterações microscópicas foram principalmente caracterizadas por extensiva desorganização de polpa branca, com a resposta esplência sendo sugerida como subotimizada. Carga parasitária, dano tecidual e resposta immune variaram mesmo em cães com quadros clínicos similares, não sendo, portanto, a análise clínica um bom parâmetro para avaliação de susceptibilidade animal à LV.
ABSTRACT
Um retrospecto histórico e epidemiológico da leishmaniose visceral (LV) no mundo e no Brasil e possíveis cenários dependentes de condicionantes ambientais, biológicos e sociais ressalta estratégias de vigilância e controle, enfatizando: associação de procedimentos com continuidade; conquistas e controvérsias em diagnóstico, tratamento, vacinação e uso de coleira com deltametrina, no cão; e ineficácia da terapêutica canina com as drogas disponíveis, mas boas perspectivas da vacina, na proteção individual, e da coleira impregnada, no controle coletivo. Considera a situação epidemiológica potencializada pela galopante urbanização da LV e sua dispersão geográfica, salientando desafios de controle por deslocamento do vetor e do cão infectado a novas áreas através do transporte rodoviário e ferroviário, e conflitos de rejeição à eutanásia canina. Alerta sobre a alta letalidade da LV humana em áreas de instalação recente e por associação crescente com HIV, impondo diagnóstico e tratamento precoces, para evitar agravamento clínico e óbitos, e adoção da busca ativa de casos humanos e caninos incorporada à rotina das visitações domiciliares periódicas da Estratégia Saúde da Família, para detecção de febre prolongada e outros sinais de LV e o encaminhamento a unidades de Saúde. Admite que a introdução do cão infectado em áreas indenes continuará um grande desafio.
A historical and epidemiological retrospect of visceral leishmaniasis (VL) in the world and in Brazil, and possible scenarios dependent of environmental, biological and social conditions stands out strategies of surveillance and control, emphasizing the association of procedures with continuity; conquests and controversies in diagnosis, treatment, vaccination and use of deltametrin collar in the dog; and ineffectiveness of canine therapy with available drugs, but good vaccine prospects, in individual protection, and impregnated collar, in collective control. It considers the epidemiological situation potentiated by the galloping urbanization of VL and its geographical dispersion, highlighting control challenges by moving the vector and the infected dog to new areas through road and rail transport, and conflicts of rejection to canine euthanasia. Alert on the high lethality of human LV in areas of recent installation and by increasing association with HIV, imposing early diagnosis and treatment, to avoid clinical worsening and death, and adoption of the active search of human and canine cases incorporated into the routine of the periodic home visits of the Family Health Strategy to detect prolonged fever and other signs of LV and referral to health units. Introducing the infected dog into free transmission areas will remain a major challenge.
Subject(s)
Humans , Animals , Dogs , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/prevention & control , Leishmaniasis, Visceral/veterinary , Epidemiological Monitoring , UrbanizationABSTRACT
In South America, visceral leishmaniasis is a zoonotic disease with severe evolution characteristics in humans, and dogs are its main reservoir. In this context, this study aimed to evaluate the clinical status of dogs from a Brazilian endemic area naturally, at Barra Mansa municipality, infected with Leishmania infantum, in conjunction with their histopathological profile and, in order to determine possible markers of susceptibility or resistance to the disease, parasitic DNA load, cytokine and iNOS mRNA expression profiles were investigated in lymph nodes. High levels of IFN-É£ and IL-6 mRNA were detected. Both IFN-É£ and IL-6 mRNA were associated with disorganization of the corticomedullary region. IFN-É£ and TNF-α mRNA were associated with the absence of follicular hyperplasia. The regulatory pathway was remarkable with IL-10 mRNA detection and its significant association with the severity of the disease. Plasmacytosis and sinus histiocytosis were associated with high loads of parasitic DNA, but there was no significant association between the parasite DNA load and animal clinical alterations. Since high parasitic loads were found in animals with or without symptoms, clinical examination cannot be considered as a criterion for disease susceptibility assessment.
Subject(s)
Cytokines/metabolism , Dog Diseases/parasitology , Leishmania infantum/genetics , Leishmaniasis, Visceral/veterinary , Lymph Nodes/metabolism , Nitric Oxide Synthase Type II/metabolism , Animals , Cytokines/genetics , DNA, Protozoan/genetics , Dogs , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/parasitology , Lymph Nodes/enzymology , Lymph Nodes/immunology , Nitric Oxide Synthase Type II/geneticsABSTRACT
Dirofilaria immitis and Dirofilaria repens infections are mosquito-borne diseases, mainly of dogs. Both parasites are zoonotic, and they sometimes cause serious infections in humans. The aim of this short review was to examine the situation in the Balkan Peninsula, from where it is not always easy to obtain suitable data, often reported in journals and other publications difficult to be retrieved and with poor or no visibility. The review included data from international and regional literature, doctoral theses, and conference proceedings.
