RESUMO
Although genetic polymorphisms in NOD2 (nucleotide-binding oligomerization domain-containing 2) have been associated with the pathogenesis of Crohn's disease (CD), little is known regarding the role of wild-type (WT) NOD2 in the gut. To date, most murine studies addressing the role of WT Nod2 have been conducted using healthy (ileitis/colitis-free) mouse strains. Here, we evaluated the effects of Nod2 deletion in a murine model of spontaneous ileitis, i.e., the SAMP1Yit/Fc (SAMP) strain, which closely resembles CD. Remarkably, Nod2 deletion improved both chronic cobblestone ileitis (by 50% assessed, as the % of abnormal mucosa at 24 wks of age), as well as acute dextran sodium sulfate (DSS) colitis. Mechanistically, Th2 cytokine production and Th2-transcription factor activation (i.e., STAT6 phosphorylation) were reduced. Microbiologically, the effects of Nod2 deletion appeared independent of fecal microbiota composition and function, assessed by 16S rRNA and metatranscriptomics. Our findings indicate that pharmacological blockade of NOD2 signaling in humans could improve health in Th2-driven chronic intestinal inflammation.
Assuntos
Colite/genética , Doença de Crohn/genética , Ileíte/genética , Mucosa Intestinal/patologia , Microbiota/genética , Proteína Adaptadora de Sinalização NOD2/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Animais , Colite/induzido quimicamente , Colite/microbiologia , Doença de Crohn/imunologia , Doença de Crohn/microbiologia , Citocinas/metabolismo , Sulfato de Dextrana , Modelos Animais de Doenças , Suscetibilidade a Doenças , Disbiose , Fezes/microbiologia , Humanos , Ileíte/imunologia , Ileíte/microbiologia , Camundongos , Camundongos Knockout , Camundongos Mutantes , Proteína Adaptadora de Sinalização NOD2/genética , RNA Ribossômico 16S/análise , Receptores de Reconhecimento de Padrão/genética , Fator de Transcrição STAT6/metabolismoRESUMO
Domestic cats have several features that make them ideal vehicles for interspecies transmission of influenza viruses; however, they have been largely overlooked as potential reservoirs or bridging hosts. In this study, we conducted serological surveillance to assess the prevalence of novel pandemic H1N1 as well as seasonal human influenza virus infections in domestic cats in Ohio. Four hundred serum samples collected from domestic cats (September 2009 to September 2010) were tested using a hemagglutination inhibition (HI) test. The seroprevalences of pandemic H1N1, seasonal H1N1, and H3N2 were 22.5%, 33%, and 43.5%, respectively. In addition, a significant association between clinical feline respiratory disease and influenza virus infection was documented. In this sample of cats, the prevalence of pandemic H1N1 did not follow the seasonality pattern of seasonal H1N1 or H3N2 influenza, similar to observations in humans. Pandemic H1N1 seroprevalence did not vary in relation to ambient temperature changes, while the seroprevalence of seasonal H3N2 and H1N1 influenza viruses increased with the decline of ambient temperature. Our results highlight the high prevalence of influenza virus infection in domestic cats, a seasonality pattern of influenza virus infection comparable to that in humans, and an association of infection with clinical respiratory disease.
Assuntos
Anticorpos Antivirais/sangue , Doenças do Gato/epidemiologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Infecções por Orthomyxoviridae/epidemiologia , Animais , Doenças do Gato/patologia , Doenças do Gato/virologia , Gatos , Feminino , Testes de Inibição da Hemaglutinação , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Masculino , Ohio/epidemiologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Estações do Ano , Estudos SoroepidemiológicosRESUMO
AIMS: The growth rate of bovine lactic acid bacteria (LAB) in five different culture conditions, and their inhibitory activity against Escherichia coli O157 and F5 in two assays was assessed to identify LAB for potential prophylactic use in cattle. METHODS AND RESULTS: 106 bovine-derived faecal/intestinal LAB were tested in vitro for tolerance to pH 2.0, pH 4.0, 0.15% and 0.3% bile, aerobic incubation, and for inhibitory activity against E. coli O157 (n = 3) and F5 (n = 1). While no LAB grew at pH 2.0, LAB survivability varied between 35% and 100% on the other tests. Exactly 7.6% (8/106) of LAB supernatants inhibited the growth of E. coli in two assays, whereas 6.6% (7/106) of isolates enhanced the growth of all E. coli strains. Partial 16s rRNA gene sequencing of six best isolates (95th percentile) revealed that five were Lactobacillus plantarum and one Pediococcus acidilactici. CONCLUSION: Lactobacillus plantarum with acid/bile and aerobic resistance and inhibitory activity against E. coli O157 and F5 inhabit the intestinal tract of healthy cattle. Some LAB may enhance E. coli growth. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus plantarum and P. acidilactici are natural plant micro-organisms and studied silage inoculants. Their identification from gastrointestinal samples of healthy cattle is prophylactically promising.
