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1.
PLoS Pathog ; 16(8): e1008763, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32834002

RESUMO

The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Colite/patologia , Variação Genética , Macrófagos/imunologia , Salmonelose Animal/patologia , Salmonella typhimurium/imunologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Linhagem da Célula , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Replicação Viral
2.
PLoS Pathog ; 16(8): e1008766, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32857822

RESUMO

Pathogens commonly disrupt the intestinal epithelial barrier; however, how the epithelial immune system senses the loss of intestinal barrier as a danger signal to activate self-defense is unclear. Through an unbiased approach in the model nematode Caenorhabditis elegans, we found that the EGL-44/TEAD transcription factor and its transcriptional activator YAP-1/YAP (Yes-associated protein) were activated when the intestinal barrier was disrupted by infections with the pathogenic bacterium Pseudomonas aeruginosa PA14. Gene Ontology enrichment analysis of the genes containing the TEAD-binding sites revealed that "innate immune response" and "defense response to Gram-negative bacterium" were two top significantly overrepresented terms. Genetic inactivation of yap-1 and egl-44 significantly reduced the survival rate and promoted bacterial accumulation in worms after bacterial infections. Furthermore, we found that disturbance of the E-cadherin-based adherens junction triggered the nuclear translocation and activation of YAP-1/YAP in the gut of worms. Although YAP is a major downstream effector of the Hippo signaling, our study revealed that the activation of YAP-1/YAP was independent of the Hippo pathway during disruption of intestinal barrier. After screening 10 serine/threonine phosphatases, we identified that PP2A phosphatase was involved in the activation of YAP-1/YAP after intestinal barrier loss induced by bacterial infections. Additionally, our study demonstrated that the function of YAP was evolutionarily conserved in mice. Our study highlights how the intestinal epithelium recognizes the loss of the epithelial barrier as a danger signal to deploy defenses against pathogens, uncovering an immune surveillance program in the intestinal epithelium.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Permeabilidade da Membrana Celular , Células Epiteliais/imunologia , Microbioma Gastrointestinal/imunologia , Salmonelose Animal/imunologia , Salmonella typhimurium/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Camundongos , Salmonelose Animal/metabolismo , Salmonelose Animal/microbiologia , Salmonelose Animal/patologia , Transdução de Sinais
3.
J S Afr Vet Assoc ; 91(0): e1-e7, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32787420

RESUMO

Chickens have been implicated in most Salmonella disease outbreaks because they act as carriers of the pathogen in their gut. There are over 2500 serotypes of Salmonella that have been reported worldwide and 2000 of these serovars can be found in chickens. The main objective of this study was to determine the Salmonella serotypes found in poultry farms around Mafikeng district, South Africa. Salmonella was identified according to the guidelines of the International Organization for Standardization (ISO) (ISO 6579:2002) standard techniques. Faecal samples were collected and analysed for Salmonella using conventional cultural methods and polymerase chain reaction targeting the 16S Ribosomal Deoxyribonucleic acid (rDNA) gene for Salmonella identification. Out of 130 presumptive Salmonella isolates determined by urease and triple sugar iron tests, only 46 isolates were identified as Salmonella serotypes of which S. Typhimurium was the most frequent with 18 (39.1%), followed by S. Heidelberg with 9 (19.6%), S. bongori with 7 (15.2%), S. Enteritidis with 6 (13.0%) and both S. Paratyphi B and S. Newport with 3 (6.5%) each. Seven virulence genes including invA 100%, spy 39%, hilA 9%, misL 30%, sdfI 13%, orfL 11% and spiC 9% were detected from these Salmonella isolates in this study. The presence of these virulence genes indicates high pathogenicity potential of these isolates which is a serious public health concern because of zoonotic potential of Salmonella.


Assuntos
Galinhas , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella/genética , Animais , DNA Bacteriano/análise , DNA Ribossômico/análise , Fezes/microbiologia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/microbiologia , Prevalência , Salmonella/isolamento & purificação , Salmonella/patogenicidade , Salmonelose Animal/microbiologia , Sorogrupo , África do Sul/epidemiologia , Virulência
4.
PLoS One ; 15(6): e0232831, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497096

RESUMO

The burden of enteric pathogens in poultry is growing after the ban of antibiotic use in animal production. Organic acids gained attention as a possible alternative to antibiotics due to their antimicrobial activities, improved nutrient metabolism and performance. The current study was conducted to evaluate the effectiveness of organic acid blend on broilers cecal microbiota, histomorphometric measurements, and short-chain fatty acid production in Salmonella enterica serovar Typhimurium challenge model. Birds were divided into four treatments, including a negative control, positive control challenged with S. Typhimurium, group supplemented with an organic acid blend, and birds supplemented with organic acid blend and Salmonella challenged. Results illustrate significant differences in feed conversion ratios and production efficiency factor between treatment groups, however, the influence of organic acid supplement was marginal. Organic acid blend significantly increased cecal acetic and butyric acids concentrations when compared to unsupplemented groups and resulted in minor alterations of intestinal bacterial communities.


Assuntos
Acetatos/metabolismo , Ração Animal , Butiratos/metabolismo , Galinhas/microbiologia , Suplementos Nutricionais , Ácidos Graxos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças das Aves Domésticas/terapia , Salmonelose Animal/terapia , Salmonella typhimurium/efeitos dos fármacos , Animais , Ceco/microbiologia , Galinhas/metabolismo , Ácidos Graxos/administração & dosagem , Ácidos Graxos Voláteis/administração & dosagem , Ácidos Graxos Voláteis/farmacologia , Íleo/metabolismo , Íleo/ultraestrutura , Mananas/administração & dosagem , Microvilosidades/ultraestrutura , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Salmonelose Animal/microbiologia , Salmonelose Animal/prevenção & controle , Salmonella typhimurium/isolamento & purificação , Salmonella typhimurium/metabolismo
5.
Int J Food Microbiol ; 330: 108559, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32599476

RESUMO

Salmonella Heidelberg resistant to ceftiofur (a third-generation cephalosporin antimicrobial agent) in broiler chicken products pose a risk to public health in Canada. The objective of this study was to assess the extent of that risk and to evaluate the effect of intervention measures along the agri-food chain. A stochastic farm-to-fork quantitative microbial risk assessment model was developed following the Codex Alimentarius Guidelines for Risk Analysis of Foodborne Antimicrobial Resistance. Different scenarios were analyzed to assess the individual relative effects of 18 possible interventions in comparison to a baseline scenario. The baseline scenario represented the first year of on-farm antimicrobial use surveillance in the Canadian broiler industry and the year before an industry-imposed ban on the preventive use of antimicrobials of very high importance to human health (2013), where 31.3% of broiler flocks consisted of birds to which ceftiofur was administered. The baseline scenario predicted an average probability of illness of 1.1 per 100,000 servings (SE: 0.064 per 100,000), corresponding to an average of 22,000 human infections (SE: 1900) with ceftiofur-resistant S. Heidelberg per year, which is likely an overestimation. This risk was reduced by 90% or 20% when two separate scenarios designed to capture the effect of withdrawing preventive ceftiofur use from poultry production were simulated using different approaches; data used for the former scenario were confounded by other potential concomitant control measures (e.g. Salmonella vaccination programme), so the true effect likely lies somewhere between the two estimates. A theoretical 'worst case' scenario where all flocks had birds exposed to ceftiofur increased the risk by 107%. A 50% reduction in the probability of human prior exposure to antimicrobials, which has a selective and competitive effect for Salmonella spp. following ingestion of contaminated products, reduced the risk by 65%. Other promising measures that could be considered for further risk management included improved cleaning and disinfection between broiler flocks on farm (risk reduction by 26%), exclusive use of air chilling (risk reduction by 34%), and the improvement of meat storage and preparation conditions, e.g., no temperature abuse at retail (risk reduction by 88%). These findings showed the importance of a structured approach to assessing and potentially implementing effective interventions to reduce the risk associated with ceftiofur-resistant S. Heidelberg at different steps along the agri-food chain. Major data gaps included information on concentrations of resistant bacteria, cross contamination at processing and how ceftiofur-resistant S. Heidelberg behave in comparison with susceptible ones, e.g., in terms of growth and survival ability, as well as pathogenicity and virulence.


Assuntos
Resistência às Cefalosporinas , Galinhas/microbiologia , Microbiologia de Alimentos , Salmonelose Animal/microbiologia , Salmonella/isolamento & purificação , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Canadá/epidemiologia , Cefalosporinas/administração & dosagem , Cefalosporinas/farmacologia , Humanos , Aves Domésticas/microbiologia , Medição de Risco , Salmonella/efeitos dos fármacos , Salmonelose Animal/epidemiologia , Salmonelose Animal/prevenção & controle
6.
PLoS Genet ; 16(6): e1008850, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32511244

RESUMO

Salmonella enterica serotype Typhimurium (S. Typhimurium) is a leading cause of gastroenteritis and bacteraemia worldwide, and a model organism for the study of host-pathogen interactions. Two S. Typhimurium strains (SL1344 and ATCC14028) are widely used to study host-pathogen interactions, yet genotypic variation results in strains with diverse host range, pathogenicity and risk to food safety. The population structure of diverse strains of S. Typhimurium revealed a major phylogroup of predominantly sequence type 19 (ST19) and a minor phylogroup of ST36. The major phylogroup had a population structure with two high order clades (α and ß) and multiple subclades on extended internal branches, that exhibited distinct signatures of host adaptation and anthropogenic selection. Clade α contained a number of subclades composed of strains from well characterized epidemics in domesticated animals, while clade ß contained multiple subclades associated with wild avian species. The contrasting epidemiology of strains in clade α and ß was reflected by the distinct distribution of antimicrobial resistance (AMR) genes, accumulation of hypothetically disrupted coding sequences (HDCS), and signatures of functional diversification. These observations were consistent with elevated anthropogenic selection of clade α lineages from adaptation to circulation in populations of domesticated livestock, and the predisposition of clade ß lineages to undergo adaptation to an invasive lifestyle by a process of convergent evolution with of host adapted Salmonella serotypes. Gene flux was predominantly driven by acquisition and recombination of prophage and associated cargo genes, with only occasional loss of these elements. The acquisition of large chromosomally-encoded genetic islands was limited, but notably, a feature of two recent pandemic clones (DT104 and monophasic S. Typhimurium ST34) of clade α (SGI-1 and SGI-4).


Assuntos
Evolução Molecular , Gastroenterite/microbiologia , Intoxicação Alimentar por Salmonella/microbiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/genética , Animais , Aves/microbiologia , Genoma Bacteriano/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Gado/microbiologia , Filogenia , Salmonelose Animal/transmissão , Salmonella typhimurium/isolamento & purificação , Salmonella typhimurium/patogenicidade , Seleção Genética , Sorogrupo , Sequenciamento Completo do Genoma
7.
Int J Food Microbiol ; 328: 108660, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32450393

RESUMO

Salmonella (S.) Infantis is currently the most common serovar in broilers and boiler meat in the European Union. In the field, eradication of S. Infantis in affected poultry flocks is considered extremely difficult. Despite stringent cleaning and disinfection measures between the placement of flocks, recurrent infections are often reported. So far, the efficacy of disinfectants on S. Infantis has rarely been studied. Therefore, in the present in-vitro study the bacteriostatic and bactericidal efficacy of ten commercial disinfectants were tested against seven S. Infantis field isolates. Combinations of aldehyde and quarternary ammonium were the active compounds of five, peroxygen of three, cresol and alkylamines of one disinfectant, respectively. Investigations were performed according to standard protocols and regulations. Different concentrations of disinfectants were used to test the bacteriostatic efficacy. Different temperatures and low and high protein exposures were applied as variables to investigate the bactericidal efficacy. Following neutralization of the disinfectants an additional incubation step was introduced to investigate the revitalisation potential of S. Infantis. The bacteriostatic efficacy could be assessed for seven disinfectants. For three disinfectants a bacteriostatic effect was observed when the recommended concentration was used, whereas with four disinfectants only increased concentrations led to this effect. The bactericidal efficacy was not influenced by temperature, whereas high protein exposure decreased the efficacy of nine disinfectants. Furthermore, reactivation of S. Infantis was revealed after application of disinfectants for the majority of products. Interestingly, the strain of S. Infantis influenced the efficacy of the disinfectants. Overall, products based on aldehydes and quarternary ammonium compounds proved most efficient, followed by peroxgen, cresol and alkylamines.


Assuntos
Antibacterianos/farmacologia , Desinfetantes/farmacologia , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/prevenção & controle , Salmonella enterica/efeitos dos fármacos , Aldeídos/farmacologia , Compostos de Amônio/farmacologia , Animais , Galinhas/microbiologia , Cresóis/farmacologia , Microbiologia de Alimentos , Carne/microbiologia , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação
8.
Poult Sci ; 99(5): 2645-2649, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359600

RESUMO

Feed additives can be alternatives to antibiotics for routinely encountered pathogens in the poultry production. The objective of this study was to understand effects of organic acid mixture on growth parameters and Salmonella Typhimurium (ST) colonization in broilers. Organic acid mixture is a feed-grade buffered formic acid and sodium formate mixture (Amasil NA). A total of 800 1-day-old Cobb500 males were fed one of the five dietary treatments: a negative control diet without ST challenge (NC), positive control diet with ST challenge (PC), 0.3% organic acid mixture with ST, 0.6% organic acid mixture with ST, and 0.9% organic acid mixture with ST. Treatments were assigned to 20 pens with 40 chicks/pen and 4 replicates of each treatment. Chickens were challenged with 107 CFU/mL of nalidixic acid-resistant ST (STNAR) 4-D posthatch. In the grower phase, feed conversion rate was significantly reduced in the 9% organic acid mixture compared with the PC. The body weight and body weight gain (BWG) were not affected either in the starter or grower phases. However, in the finisher phase, the nonchallenged NC had higher BWG than the PC (P < 0.05), whereas there were no differences in BWG among the NC and organic acid mixture fed groups. In addition, there was a significant effect of organic acid mixture on the colonization of cecal STNAR. At 9 dpi, cecal STNAR was 3.28 log10 in the PC that was reduced to 2.65 log10 at 0.3%, 1.40 log10 at 0.6%, and 0.84 log10 in 0.9% organic acid mixture. At 24 dpi, cecal STNAR recovery was 0.81, 0.99, 0.53, and 0.33 log10 in the PC and 0.3, 0.6, and 0.9% organic acid mixture, respectively. Similarly, at 38 dpi, cecal STNAR was 0.26, 0.11, 0.33, and 0 log10 in the PC, 0.3, 0.6, and 0.9%, respectively. These results show that organic acid mixture can be one dietary strategy to control ST infection and maintain efficient growth performance.


Assuntos
Galinhas , Formiatos/metabolismo , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/fisiologia , Ração Animal/análise , Animais , Antibacterianos/farmacologia , Peso Corporal/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Formiatos/administração & dosagem , Masculino , Ácido Nalidíxico/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Ganho de Peso/efeitos dos fármacos
9.
Poult Sci ; 99(5): 2684-2689, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359605

RESUMO

The genetic relatedness and antimicrobial susceptibility profiles of Salmonella isolated from poultry and their environment were determined. One broiler breeder flock (BBF1) and 2 broiler flocks (BF1 and BF2) were reared over a 1.75-year period on the same poultry research farm. Hatching eggs were obtained from BBF1 to produce BF1 chicks, while BF2 chicks were progeny of a separate, unsampled broiler breeder flock. BF1 and BF2 were reared in the same housing facilities but 6 mo apart. Salmonella isolates were collected via litter sock sampling (BF1), cecal excision (BF1 and BF2), or cloacal swabs (BBF1). Serotyping identified Salmonella enterica subsp. enterica serovar Altona (SA) in BBF1 and S. enterica subsp. enterica serovar Senftenberg (SS) in BF1 and BF2. Genotypic fingerprinting was achieved with Rep-PCR using the (GTG)5 primer and revealed sequence homology among Senftenberg isolates from BF1 and BF2. For each isolate, the minimum inhibitory concentration was determined for 27 antimicrobial agents using Sensititre plates with formularies specific to antimicrobials used in poultry production or those used to control gram negative pathogens. Isolates from the 3 flocks were resistant to clindamycin, erythromycin, novobiocin, penicillin, and tylosin tartrate and demonstrated intermediate resistance to azithromycin, florfenicol, and spectinomycin. These data demonstrated that serovar Altona and Senftenberg were harbored by poultry, the latter appeared to persist in broiler flocks, and both serotypes shared similar patterns of antimicrobial susceptibility in an integrated research operation. In the case of multiple Salmonella isolates, combining genotypic fingerprinting methods with serotyping of representative isolates would reduce the number of samples required for serotyping and more clearly identify relatedness of isolates. These methods facilitate effective surveillance in poultry production systems, thus allowing for implementation of precise Salmonella control measures.


Assuntos
Galinhas , Impressões Digitais de DNA/veterinária , Farmacorresistência Bacteriana/genética , Monitoramento Epidemiológico/veterinária , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella/isolamento & purificação , Animais , Antibacterianos/farmacologia , Técnicas de Genotipagem/veterinária , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/microbiologia , Prevalência , Salmonella/genética , Salmonelose Animal/microbiologia , Sorotipagem/veterinária
10.
Int J Food Microbiol ; 325: 108640, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32344254

RESUMO

Although a nation-wide microbiological screening program of chicken carcasses after chilling in Taiwanese chicken abattoirs has been undertaken since 2006, little is known regarding the potential sources of the Salmonella during the slaughter process. The present study provides data on the detection and serotypes of Salmonella isolated from broilers during processing and from the environment in six abattoirs in Taiwan. Overall, Salmonella were detected in 156 of 622 samples (25.1%; 95% CI: 21.7-28.7) collected. The prevalence of Salmonella varied between sampling sites with 5.8, 17.6, 31.3 and 35.5% of cloacal swabs, environmental samples prior to processing, environmental samples during processing and carcass rinse fluid, respectively, being positive (χ2 = 51.3, p < 0.0001). A total of 15 serotypes were identified from the 156 Salmonella isolates with S. Albany (41.7%) S. Schwarzengrund (20.5%), S. Kentucky (12.8%) and S. Tennessee (5.1%) being the most commonly isolated serotypes. Characterization of 156 isolates by Pulse Field Gel Electrophoresis (PFGE) identified 50 PFGE types. Typing confirmed the presence of the same PFGE type at multiple stages during processing including plucking, evisceration, chilling and post-chilling. The abattoir environment and intestinal contents of chickens are important sources of Salmonella in broiler chicken abattoirs, with the same PFGE types detected at different stages of processing both before and during slaughtering. It is concluded that Salmonella isolates present in the environment and intestinal contents of processed birds survived in the abattoir environment resulting in subsequent carcass contamination along the processing chain including plucking, evisceration, chilling and post-chilling.


Assuntos
Galinhas/microbiologia , Carne/microbiologia , Salmonella enterica/isolamento & purificação , Matadouros , Animais , Eletroforese em Gel de Campo Pulsado , Microbiologia de Alimentos , Intestinos/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Sorogrupo , Taiwan
11.
Avian Dis ; 64(1): 7-15, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32267120

RESUMO

Salmonella enterica serovar Enteritidis is the leading cause of salmonellosis in people, and modeling of infections in chickens is used to identify intervention strategies. A review of 80 manuscripts encompassing 119 experiments indicated that the mean dose of infection was 108 CFU per bird. Experiments of less than 106 CFU were primarily conducted in immature birds. To address a lack of information on the impact of low dosages on the hen at lay, two experiments were conducted in triplicate. Experiment A addressed issues associated with vaccination; thus, hens were infected intramuscularly at 103, 105, and 107 CFU. For Experiment B, which was focused more on colonization and invasion, hens were infected orally with 5 × 103 CFU with 4 strains from different genomic clades. Samples from liver, spleen, ovarian pedicle, and paired ceca in both experiments were cultured 5, 6, 7, and 8 days postinfection. Eggshell microbiome taxa were assessed in Experiment B. Results indicated that dosages of 103 CFU in both experiments produced enough positive samples to be used within models. The intramuscular route resulted in approximately twice as many positive samples as the oral route. The kinetics of infection appeared to differ between low and high dosages suggestive of a J-curve response. These results could impact risk assessments if the hen at lay has a nonlinear response to infectious dose.


Assuntos
Galinhas , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enteritidis/fisiologia , Animais , Ceco/microbiologia , Feminino , Genoma Bacteriano , Fígado/microbiologia , Ovário/microbiologia , Reprodução , Salmonella enteritidis/genética , Baço/microbiologia
12.
Avian Dis ; 64(1): 46-52, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32267124

RESUMO

Rodents serve as amplifiers of Salmonella infections in poultry flocks and can serve as a source of Salmonella contamination in the environment even after thorough cleaning and disinfection. This study aims to determine the dynamics of Salmonella occurrence in rodents and its relation to Salmonella contamination in the layer farm environment, including air dusts and eggs. From 2008 to 2017, roof rats (Rattus rattus), environmental swabs, air dusts, and eggs were collected from an intensive commercial layer farm in East Japan and were tested for Salmonella spp. using standard procedures. In roof rat samples, the Salmonella isolation rate was reached at 10% (95% confidence interval [CI] 8.1-21.9) in which Salmonella Corvallis, Salmonella Infantis, Salmonella Potsdam, and Salmonella Mbandaka were the frequent isolates from the cecal portion of the intestines. On the other hand, the prevalence rate of Salmonella in environmental swabs was at 5.1% (95% CI 2.2-7.4) while air dusts were at 0.9% (95% CI 0.2-1.8). It was observed that the prevalence of predominant Salmonella serotypes shifted over time; in roof rats, it was noted that Salmonella Potsdam gradually replaced Salmonella Infantis. In environmental swabs and eggs, Salmonella Corvallis and Salmonella Potsdam increased significantly while Salmonella Infantis became less frequent. In air dusts, Salmonella Corvallis was observed to decrease and Salmonella Potsdam became more common. Based on our findings, the role of roof rats in the epidemiology of Salmonella in layer farms was expanded from being a reservoir and an amplifier host into a shifting vessel of the most predominant serotypes.


Assuntos
Galinhas , Doenças das Aves Domésticas/transmissão , Ratos , Salmonelose Animal/transmissão , Salmonella/fisiologia , Animais , Abrigo para Animais , Japão/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Prevalência , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-32293934

RESUMO

The transport of electrolytes and fluid by the intestinal epithelium is critical in health to maintain appropriate levels of fluidity of the intestinal contents. The transport mechanisms that underlie this physiological process are also subject to derangement in various digestive disease states, such as diarrheal illnesses. This article summarizes the 2019 Hans Ussing Lecture of the Epithelial Transport Group of the American Physiological Society and discusses some pathways by which intestinal transport is dysregulated, particularly in the setting of infection with the diarrheal pathogen, Salmonella, and in patients treated with small-molecule inhibitors of the tyrosine kinase activity of the epidermal growth factor receptor (EGFr-TKI). The burdensome diarrhea in patients infected with Salmonella may be attributable to decreased expression of the chloride-bicarbonate exchanger downregulated in adenoma (DRA) that participates in electroneutral NaCl absorption. This outcome is possibly secondary to increased epithelial proliferation and/or decreased epithelial differentiation that occurs following infection. Conversely, the diarrheal side effects of cancer treatment with EGFr-TKI may be related to the known ability of EGFr-associated signaling to reduce calcium-dependent chloride secretion. Overall, the findings described may suggest targets for therapeutic intervention in a variety of diarrheal disease states.


Assuntos
Antiporters/metabolismo , Diarreia/metabolismo , Células Epiteliais/metabolismo , Absorção Intestinal , Mucosa Intestinal/metabolismo , Transportadores de Sulfato/metabolismo , Animais , Antineoplásicos/toxicidade , Diferenciação Celular , Proliferação de Células , Diarreia/induzido quimicamente , Diarreia/microbiologia , Diarreia/patologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Camundongos , Permeabilidade , Inibidores de Proteínas Quinases/toxicidade , Salmonelose Animal/metabolismo , Salmonelose Animal/microbiologia , Salmonelose Animal/patologia
14.
Arch Razi Inst ; 75(1): 93-99, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32292007

RESUMO

Salmonellosis as a zoonotic disease in dogs is not fully understood, and various reports have pointed to the transmission of antibiotic-resistant salmonella from dogs to humans. The current study aimed to evaluate the serologic and bacteriologic prevalence of Salmonella spp. in stray dogs placed in animal shelters around Tehran, compare the results to those of asymptomatic dogs, and determine the serotype of isolated species, as well as their antibiotic susceptibility pattern. A total of 100 fecal swab and blood samples were obtained from symptomatic and apparently healthy dogs (clinically) placed in four animal shelters around Tehran, Iran. Fecal and blood culture, as well as dog food culture, tube agglutination test, serotyping, and antibiotic susceptibility testing were performed on the samples. Fever, lethargy, diarrhea, and abdominal pain were observed in all the dogs in the case group, and bloody diarrhea was the least commonly detected symptom in clinical examination. A number of 11 and 4 collected fecal swabs from the case and control groups were positive for Salmonella spp., respectively. The polymerase chain reaction (PCR) also confirmed the laboratory tests results. Blood culture on the selective medium was negative for all the cases. Moreover, 60% and 100% of dogs in the case and control groups showed inflammatory markers in their blood test. The tube agglutination test was positive for 12% of the samples from the case group, while it was positive only for 5% of cases in the control group. The highest and lowest antibiotic resistance was observed against gentamicin and ciprofloxacin from the case group, respectively. Salmonella spp. infection in stray dogs placed in animal shelters is a great public health concern. In this regard, it is recommended that these animals be regularly monitored since they serve as Salmonella carriers.


Assuntos
Doenças do Cão/epidemiologia , Farmacorresistência Bacteriana , Salmonelose Animal/epidemiologia , Salmonella/efeitos dos fármacos , Salmonella/fisiologia , Animais , Estudos de Casos e Controles , Doenças do Cão/microbiologia , Cães , Feminino , Irã (Geográfico)/epidemiologia , Masculino , Prevalência , Salmonelose Animal/microbiologia , Estudos Soroepidemiológicos , Sorogrupo
15.
Poult Sci ; 99(4): 1862-1874, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241466

RESUMO

This study was conducted to investigate the effects of dietary arginine (Arg) supplementation on the inflammatory response and gut microbiota of broiler chickens subjected to Salmonella enterica serovar Typhimurium. One hundred and forty 1-day-old Arbor Acres male birds were randomly assigned to a 2 × 2 factorial arrangement including diet treatment (with or without 0.3% Arg supplementation) and immunological stress (with or without S. typhimurium challenge). Samples were obtained at 7 D after infection (day 23). Results showed that S. typhimurium challenge caused histopathological and morphological damages, but Arg addition greatly reduced these intestinal injuries. S. typhimurium challenge elevated the levels of serum inflammatory parameters, including diamine oxidase, C-reactive protein, procalcitonin, IL-1ß, IL-8, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITNF) homolog. However, Arg supplementation decreased the serum procalcitonin, IL-1ß, IL-8, and LITNF concentration. S. typhimurium challenge significantly increased jejunal IL-1ß, IL-8, IL-10, and IL-17 mRNA expression and tended to upregulate IL-22 mRNA expression, but Arg supplementation remarkably reduced IL-8 mRNA expression, tended to downregulate IL-22 mRNA expression, and dramatically elevated IFN-γ and IL-10 mRNA expression. In addition, sequencing data of 16S rDNA indicated that the population of Proteobacteria phylum; Enterobacteriaceae family; Escherichia-Shigella, and Nitrosomonas genera; and Escherichia coli and Ochrobactrum intermedium species were more abundant, but the population of Rhodocyclaceae and Clostridiaceae_1 families and Candidatus Arthromitus genus were less abundant in the ileal digesta of birds with only S. typhimurium infection when compared with the controls. Treatment with Arg in birds subjected to S. typhimurium challenge increased the abundances of Firmicutes phylum, Clostridiaceae_1 family, Methylobacterium and Candidatus Arthromitus genera but decreased the abundance of Nitrosomonas genus and Rhizobium cellulosilyticum and Rubrobacter xylanophilus species as compared with the only S. typhimurium-challenged birds. In conclusion, Arg supplementation can alleviate intestinal mucosal impairment by ameliorating inflammatory response and modulating gut microbiota in broiler chickens challenged with S. typhimurium.


Assuntos
Arginina/metabolismo , Fenômenos Fisiológicos Bacterianos , Galinhas/imunologia , Microbioma Gastrointestinal/fisiologia , Inflamação/veterinária , Salmonella typhimurium/fisiologia , Ração Animal/análise , Animais , Arginina/administração & dosagem , Galinhas/microbiologia , Dieta/veterinária , Suplementos Nutricionais/análise , Inflamação/tratamento farmacológico , Inflamação/microbiologia , Intestinos/anatomia & histologia , Intestinos/microbiologia , Intestinos/patologia , Masculino , Doenças das Aves Domésticas/microbiologia , Distribuição Aleatória , Salmonelose Animal/microbiologia , Estresse Fisiológico/imunologia
16.
Poult Sci ; 99(4): 2136-2145, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241499

RESUMO

This study investigated the prevalence of Salmonella and the molecular typing of all isolates in a goose production chain including hatchery, farm, slaughterhouse, and market. A total of 350 Salmonella isolates was detected from 1,030 samples, and 13 serotypes were recovered. The highest Salmonella contamination frequency was observed at the hatchery, which 51.8% (188/363) of samples were Salmonella positive. S. Potsdam and S. Typhimurium were the 2 most common serotypes. S. Potsdam was most frequently found in the hatchery, while S. Typhimurium was widely distributed in the goose production chain. In general, the antibiotic resistance of Salmonella isolates is low, which isolates from the market is comparatively higher than from other production links indicating a possibility of Salmonella cross-contamination in the market. By the multilocus sequence typing (MLST) analysis, 7 different ST types were identified. ST2039 was the most common ST type, which was mostly found from S. Potsdam isolates in hatchery indicating that S. Potsdam might have been long existed in hatchery. The pulsed-field gel electrophoresis (PFGE) analysis of S. Potsdam indicated that S. Potsdam could be transmitted along the production chain. The PFGE analysis of S. Typhimurium showed that PFGE pattern 29 (PF29) was distributed in hatchery, and also in farm and from humans indicating the risk of S. Typhimurium transmitting to humans by the food supply chain. Our study provided the evidence of Salmonella cross-contamination in the slaughterhouse and the retail market of goose production chain, and specific serotypes existed for a long time at a particular production link. The spread of Salmonella along the production chain, might cause harm to humans through cross-contamination. Further studies would be needed to control the Salmonella contamination in hatchery and prevent the transmission of the pathogen during the goose production.


Assuntos
Gansos , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella/isolamento & purificação , Animais , China/epidemiologia , Eletroforese em Gel de Campo Pulsado/veterinária , Tipagem de Sequências Multilocus/veterinária , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/transmissão , Prevalência , Salmonelose Animal/microbiologia , Salmonelose Animal/transmissão
17.
Res Vet Sci ; 130: 161-169, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32193003

RESUMO

Non-typhoidal Salmonella is considered a major public health concern. The growing relevance of pigs as reservoir of Salmonella spp. has prompted several countries to set up surveillance and control programs to fight Salmonella infection in swine and reduce public health risk. In the last decade, pork production in Córdoba increased significantly to become one of the most important pig production provinces in Argentina. The aim of this study was to estimate Salmonella spp. prevalence and associated risk factors in large scale-farms in this province. Mesenteric lymph nodes (MLN) of 580 pigs from 20 finishing large-scale farms were collected between 2014 and 2015 to estimate Salmonella infection. A prevalence of 41.5% (95%CI: 37.6-45.6%) was observed. Two major risk factors were significantly associated with Salmonella infection, both related to the pre-slaughter period (distance from the farm to the slaughterhouse and lairage time), highlighting the need to pay special attention to pre-slaughter practices in the province. Shortening transport times and complying with national regulations for lairage time at slaughter may help to reduce the prevalence of infection. Sixteen different serovars were identified, being S. Anatum and S. Typhimurium the most prevalent ones. Moreover, two isolate of the monophasic variant of Salmonella Typhimurium (I 4,5,12:i:-) resistant to enrofloxacin and which also displayed multidrug resistance was isolated for first time from pigs in Córdoba. The moderate to high levels of antimicrobial resistance detected for antibiotics commonly used in the pig sector suggested the need for implementing a plan to limit their use in the province.


Assuntos
Farmacorresistência Bacteriana , Salmonelose Animal/epidemiologia , Salmonella/efeitos dos fármacos , Doenças dos Suínos/epidemiologia , Criação de Animais Domésticos , Animais , Antibacterianos/farmacologia , Argentina/epidemiologia , Prevalência , Fatores de Risco , Salmonella/fisiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/fisiologia , Sus scrofa , Suínos , Doenças dos Suínos/microbiologia
18.
Res Vet Sci ; 130: 179-183, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32199176

RESUMO

S. Pullorum is a causative agent of enteric disease of poultry with serious diarrhea. However, the detailed mechanism behind its injury to intestinal mucosa barrier, especially for intestinal stem cells, is unclear. In this study, S. Pullorum were orally administrated to 3 days old chicken to investigate the pathogenesis of S. Pullorum on intestinal mucosal barrier, especially on the proliferation of epithelial cells. We found that S. Pullorum could colonize in the cecum and invade into the liver through intestinal mucosa damage, which caused obvious pathological changes in liver and intestine and even leaded to death, as well as significant reduction of body weight. We also found that S. Pullorum infection enhanced the mRNA expression of IL-1ß and IL-6 through TLR4/MyD88 pathway, which was also further verified by the increased lipopolysaccharide (LPS) levels in serum. Furthermore, S. Pullorum increased the depth of crypt and density of PCNA+ cells significantly through the over-activation of Wnt/ß-catenin signaling pathway. The expression of intestinal stem cells markers Lgr5 and Bmi1 was also increased after S. Pullorum infection to support the crypt hyperplasia. In addition, we verified that S. Pullorum infection enhanced the mRNA expression of IL-1ß, TLR4, Lgr5 and Bmi1. Our study indicated that S. Pullorum infection damaged the intestinal mucosa barrier to induce diarrhea, affected the abnormal proliferation of intestinal stem cells by over-activation of Wnt/ß-catenin pathway in chicken.


Assuntos
Galinhas , Hiperplasia/veterinária , Enteropatias/veterinária , Doenças das Aves Domésticas/fisiopatologia , Salmonelose Animal/fisiopatologia , Salmonella enterica/fisiologia , Animais , Proteínas Aviárias/fisiologia , Hiperplasia/microbiologia , Hiperplasia/fisiopatologia , Enteropatias/microbiologia , Enteropatias/fisiopatologia , Intestinos/fisiopatologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/patogenicidade , Transdução de Sinais , Células-Tronco/metabolismo , Virulência , Via de Sinalização Wnt , beta Catenina/fisiologia
19.
Poult Sci ; 99(3): 1387-1394, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111313

RESUMO

The antibacterial properties of egg yolk antibodies have been known for many years. Enhanced antibiotic resistance has resulted in increased need for using these antibodies as an alternative. In the present study, generation, capsulation, and inhibition growth properties of IgY directed against Salmonella enterica subsp. enterica serovar Infantis (SI) were evaluated. White Leghorn layer hens were immunized using whole cell of inactivated SI. Salmonella Infantis-specific antibody activities in sera and egg yolk were determined by ELISA. A total of 480 one-day-old male "Cobb 500" chicks were randomly divided into 8 groups, with 6 replications of 10 birds kept for 21 D. All birds from 7 challenged groups were orally inoculated with 1 mL of SI suspension (1 × 107 CFU/mL) at 3 and 4 D of age. Two groups were dietary supplemented with 5 g/kg immune powdered yolk or nonimmune powdered yolk. One group was dietary supplemented with 12.8 g/kg capsulated immune yolk (CIY). Two groups were given 8.3 mL/L of immune water-soluble yolk or nonimmune water-soluble yolk fraction in drinking water. In the antibiotic group, 1 mL/L Enrofloxacin 10% was added to drinking water. All supplements except for the antibiotic (on Day 4 for 10 D) were added on day one and continued during the experiment. Negative and positive control groups received no supplements. During the experiment, among the challenged groups, the minimum SI cecal colonization and the lowest isolation of SI from the liver (P < 0.01) was observed in the antibiotic group. Following antibiotic group, in the group receiving CIY, colonization of bacteria in ceca and liver was significantly reduced during the second and third weeks of the experiment (P < 0.01). According to the results, capsulated specific IgY has a beneficial effect in reducing the colonization of Salmonella under the conditions of this study in comparison with other forms of IgY antibody.


Assuntos
Anticorpos Antibacterianos/imunologia , Galinhas , Gema de Ovo/fisiologia , Imunoglobulinas/imunologia , Doenças das Aves Domésticas/prevenção & controle , Salmonelose Animal/prevenção & controle , Salmonella enterica/fisiologia , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Intestinos/microbiologia , Masculino , Doenças das Aves Domésticas/microbiologia , Distribuição Aleatória , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Sorogrupo
20.
Microb Genom ; 6(2)2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32003708

RESUMO

To establish the prevalence of mobile colistin resistance (mcr) genes amongst Salmonella enterica isolates obtained through public health surveillance in England (April 2014 to September 2017), 33 205 S. enterica genome sequences obtained from human, food, animal and environmental isolates were screened for the presence of mcr variants 1 to 8. The mcr-positive genomes were assembled, annotated and characterized according to plasmid type. Nanopore sequencing was performed on six selected isolates with putative novel plasmids, and phylogenetic analysis was used to provide an evolutionary context for the most commonly isolated clones. Fifty-two mcr-positive isolates were identified, of which 32 were positive for mcr-1, 19 for mcr-3 and 1 for mcr-5. The combination of Illumina and Nanopore sequencing identified three novel mcr-3 plasmids and one novel mcr-5 plasmid, as well as the presence of chromosomally integrated mcr-1 and mcr-3. Monophasic S. enterica serovar Typhimurium accounted for 27/52 (52 %) of the mcr-positive isolates, with the majority clustering in clades associated with travel to Southeast Asia. Isolates in these clades were associated with a specific plasmid range and an additional extended-spectrum beta-lactamase genotype. Routine whole-genome sequencing for public health surveillance provides an effective screen for novel and emerging antimicrobial determinants, including mcr. Complementary long-read technologies elucidated the genomic context of resistance determinants, offering insights into plasmid dissemination and linkage to other resistance genes.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Colistina/farmacologia , Genoma Bacteriano , Salmonella enterica/genética , Animais , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana , Inglaterra/epidemiologia , Microbiologia Ambiental , Microbiologia de Alimentos , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Plasmídeos/genética , Plasmídeos/metabolismo , Vigilância em Saúde Pública , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificação
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