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1.
Vet Res ; 52(1): 125, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593043

RESUMO

Efficient in vivo delivery of a CRISPR/Cas9 plasmid is of paramount importance for effective therapy. Here, we investigated the usability of Salmonella as a plasmid carrier for in vivo therapy against virus-induced cancer using Marek's disease virus (MDV) as a model for study in chickens. A green fluorescent protein-expressing CRISPR/Cas9 plasmid encoding the virulence gene pp38 was constructed against Marek's disease virus. Therapeutic plasmids were transformed into Salmonella carrying lon and sifA gene deletions. The animals in 5 groups were intraperitoneally inoculated with phosphate-buffered saline, vector control, or Salmonella before or after MDV infection, or left uninfected as a naïve control. Therapeutic effectiveness was evaluated by observing disease outcomes and the viral copy number in peripheral blood mononuclear cells. The efficacy of plasmid delivery by Salmonella was 13 ± 1.7% in the spleen and 8.0 ± 1.8% in the liver on the 6th day post-infection. The Salmonella-treated groups showed significant resistance to MDV infection. The maximum effect was observed in the group treated with Salmonella before MDV infection. None of the chickens fully recovered; however, the results suggested that timely delivery of Salmonella could be effective for in vivo CRISPR/Cas9-mediated genetic interference against highly pathogenic MDV. The use of Salmonella in CRISPR systems provides a simpler and more efficient platform for in vivo therapy with CRISPR than the use of conventional in vivo gene delivery methods and warrants further development.


Assuntos
Sistemas CRISPR-Cas , Galinhas , Herpesvirus Galináceo 2/fisiologia , Doença de Marek/prevenção & controle , Plasmídeos/uso terapêutico , Doenças das Aves Domésticas/prevenção & controle , Salmonella/fisiologia , Animais , Feminino , Leucócitos Mononucleares/virologia , Doença de Marek/patologia , Doença de Marek/virologia , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Salmonella/virologia
2.
Vet Res ; 52(1): 123, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34563266

RESUMO

Salmonella enterica ssp. enterica serovars Enteritidis (SE) and Gallinarum (SG) cause different diseases in chickens. However, both are able to reach the blood stream where heterophils and monocytes are potentially able to phagocytose and kill the pathogens. Using an ex vivo chicken whole blood infection model, we compared the complex interactions of the differentially host-adapted SE and SG with immune cells in blood samples of two White Leghorn chicken lines showing different laying performance (WLA: high producer; R11: low producer). In order to examine the dynamic interaction between peripheral blood leucocytes and the Salmonella serovars, we performed flow cytometric analyses and survival assays measuring (i) leucocyte numbers, (ii) pathogen association with immune cells, (iii) Salmonella viability and (iv) immune gene transcription in infected whole blood over a four-hour co-culture period. Inoculation of blood from the two chicken lines with Salmonella led primarily to an interaction of the bacteria with monocytes, followed by heterophils and thrombocytes. We found higher proportions of monocytes associated with SE than with SG. In blood samples of high producing chickens, a decrease in the numbers of both heterophils and Salmonella was observed. The Salmonella challenge induced transcription of interleukin-8 (IL-8) which was more pronounced in SG- than SE-inoculated blood of R11. In conclusion, the stronger interaction of monocytes with SE than SG and the better survivability of Salmonella in blood of low-producer chickens shows that the host-pathogen interaction and the strength of the immune defence depend on both the Salmonella serovar and the chicken line.


Assuntos
Galinhas , Leucócitos/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enteritidis/fisiologia , Salmonella/fisiologia , Animais , Feminino , Doenças das Aves Domésticas/fisiopatologia
3.
Avian Dis ; 65(1): 159-164, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-34339135

RESUMO

The present report describes an outbreak of Pullorum disease in a young layer parent stock in Austria. The flock, which comprised 14,220 Lohmann brown layer chickens, experienced high mortality from the first week of life, reaching a total of 1905 chickens in the fifth week, when the flock was depopulated. Clinical signs included uneven size of the chicks, pasty vents, apathy, and diminished water and feed intake, with some birds presenting central nervous system signs such as tremors and torticollis. The postmortem investigation of 43 birds, of ages 1 to 4 weeks, revealed retained yolk sacs filled with caseous exudate, purulent airsacculitis, hepatitis with whitish pinpoint coalescing necrotic foci, splenitis with splenomegaly, hemorrhagic-mucoid enteritis in the small intestine, fibrinous typhlitis, nephromegaly, and urate deposits in the ureters and cloaca. Inflammation and/or necrosis were identified in liver, spleen, kidney, small intestine, and heart by histopathology. However, no histopathologic lesions were observed in the brain. Salmonella enterica was isolated from heart, liver, spleen, and brain in pure culture. Group-specific serotyping determined the presence of group D, with S. enterica subspecies enterica serovar Gallinarum being confirmed based on the Kauffmann-White scheme. A duplex PCR further identified S. enterica subspecies enterica serovar Gallinarum biovar Pullorum as the responsible agent for the outbreak. Subsequently, the grandparent flocks, from which the affected flock originated, were tested and found to be negative for Salmonella Pullorum, with no other progenies from the same grandparents developing disease. Although the source of the pathogen could not be identified, such findings highlight the importance of "old" pathogens such as Salmonella Pullorum causing sudden high mortality in chicks, even in a highly controlled environment.


Assuntos
Infecções Bacterianas do Sistema Nervoso Central/veterinária , Galinhas , Surtos de Doenças/veterinária , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Animais , Áustria/epidemiologia , Infecções Bacterianas do Sistema Nervoso Central/epidemiologia , Infecções Bacterianas do Sistema Nervoso Central/microbiologia , Infecções Bacterianas do Sistema Nervoso Central/patologia , Feminino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Salmonella/fisiologia , Salmonelose Animal/microbiologia , Salmonelose Animal/patologia
4.
J Vet Sci ; 22(5): e68, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34423604

RESUMO

BACKGROUND: Colistin and carbapenem-resistant bacteria have emerged and become a serious public health concern, but their epidemiological data is still limited. OBJECTIVES: This study examined colistin and carbapenem resistance in Escherichia coli and Salmonella from pigs, pig carcasses, and pork in Thailand, Lao PDR, and Cambodia border provinces. METHODS: The phenotypic and genotypic resistance to colistin and meropenem was determined in E. coli and Salmonella obtained from pigs, pig carcasses, and pork (n = 1,619). A conjugative experiment was performed in all isolates carrying the mcr gene (s) (n = 68). The plasmid replicon type was determined in the isolates carrying a conjugative plasmid with mcr by PCR-based replicon typing (n = 7). The genetic relatedness of mcr-positive Salmonella (n = 11) was investigated by multi-locus sequence typing. RESULTS: Colistin resistance was more common in E. coli (8%) than Salmonella (1%). The highest resistance rate was found in E. coli (17.8%) and Salmonella (1.7%) from Cambodia. Colistin-resistance genes, mcr-1, mcr-3, and mcr-5, were identified, of which mcr-1 and mcr-3 were predominant in E. coli (5.8%) and Salmonella (1.7%), respectively. The mcr-5 gene was observed in E. coli from pork in Cambodia. Two colistin-susceptible pig isolates from Thailand carried both mcr-1 and mcr-3. Seven E. coli and Salmonella isolates contained mcr-1 or mcr-3 associated with the IncF and IncI plasmids. The mcr-positive Salmonella from Thailand and Cambodia were categorized into two clusters with 94%-97% similarity. None of these clusters was meropenem resistant. CONCLUSIONS: Colistin-resistant E. coli and Salmonella were distributed in pigs, pig carcasses, and pork in the border areas. Undivided-One Health collaboration is needed to address the issue.


Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Proteínas de Escherichia coli/genética , Escherichia coli/fisiologia , Carne de Porco/microbiologia , Salmonella/fisiologia , Animais , Camboja , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Laos , Plasmídeos/fisiologia , Salmonella/genética , Sus scrofa , Tailândia
5.
Sci Rep ; 11(1): 17214, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34446765

RESUMO

Salmonella enterica serovar Gallinarum is a host-restricted bacterial pathogen that causes a serious systemic disease exclusively in birds of all ages. Salmonella enterica serovar Typhimurium is a host-generalist serovar. Dendritic cells (DCs) are key antigen-presenting cells that play an important part in Salmonella host-restriction. We evaluated the differential response of chicken blood monocyte-derived dendritic cells (chMoDCs) exposed to S. Gallinarum or S. Typhimurium. S. Typhimurium was found to be more invasive while S. Gallinarum was more cytotoxic at the early phase of infection and later showed higher resistance against chMoDCs killing. S. Typhimurium promoted relatively higher upregulation of costimulatory and other immune function genes on chMoDCs in comparison to S. Gallinarum during early phase of infection (6 h) as analyzed by real-time PCR. Both Salmonella serovars strongly upregulated the proinflammatory transcripts, however, quantum was relatively narrower with S. Gallinarum. S. Typhimurium-infected chMoDCs promoted relatively higher proliferation of naïve T-cells in comparison to S. Gallinarum as assessed by mixed lymphocyte reaction. Our findings indicated that host restriction of S. Gallinarum to chicken is linked with its profound ability to interfere the DCs function. Present findings provide a valuable roadmap for future work aimed at improved vaccine strategies against this pathogen.


Assuntos
Células Dendríticas/imunologia , Monócitos/imunologia , Salmonella typhimurium/imunologia , Salmonella/imunologia , Animais , Antígeno B7-1/genética , Antígeno B7-1/imunologia , Antígenos CD40/genética , Antígenos CD40/imunologia , Galinhas , Citocinas/genética , Citocinas/imunologia , Citotoxicidade Imunológica/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/microbiologia , Expressão Gênica/imunologia , Interações Hospedeiro-Patógeno/imunologia , Viabilidade Microbiana/imunologia , Monócitos/citologia , Salmonella/fisiologia , Salmonella typhimurium/fisiologia , Especificidade da Espécie , Linfócitos T/imunologia , Linfócitos T/metabolismo , Receptores Toll-Like/genética , Receptores Toll-Like/imunologia
6.
Int J Food Microbiol ; 354: 109283, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34140188

RESUMO

Variation observed in heat inactivation of Salmonella strains (data from Combase) was characterized using multilevel modeling with two case studies. One study concerned repetitions at one temperature, the other concerned isothermal experiments at various temperatures. Multilevel models characterize variation at various levels and handle dependencies in the data. The Weibull model was applied using Bayesian regression. The research question was how parameters varied with experimental conditions and how data can best be analyzed: no pooling (each experiment analyzed separately), complete pooling (all data analyzed together) or partial pooling (connecting the experiments while allowing for variation between experiments). In the first case study, level 1 consisted of the measurements, level 2 of the group of repetitions. While variation in the initial number parameter was low (set by the researchers), the Weibull shape factor varied for each repetition from 0.58-1.44, and the rate parameter from 0.006-0.074 h. With partial pooling variation was much less, with complete pooling variation was strongly underestimated. In the second case study, level 1 consisted of the measurements, level 2 of the group of repetitions per temperature experiment, level 3 of the cluster of various temperature experiments. The research question was how temperature affected the Weibull parameters. Variation in initial numbers was low (set by the researchers), the rate parameter was obviously affected by temperature, the estimate of the shape parameter depended on how the data were analyzed. With partial pooling, and one-step global modeling with a Bigelow-type model for the rate parameter, shape parameter variation was minimal. Model comparison based on prediction capacity of the various models was explored. The probability distribution of calculated decimal reduction times was much narrower using multilevel global modeling compared to the usual single level two-step approach. Multilevel modeling of microbial heat inactivation appears to be a suitable and powerful method to characterize and quantify variation at various levels. It handles possible dependencies in the data, and yields unbiased parameter estimates. The answer on the question "to pool or not to pool" depends on the goal of modeling, but if the goal is prediction, then partial pooling using multilevel modeling is the answer, provided that the experimental data allow that.


Assuntos
Análise de Dados , Microbiologia de Alimentos , Temperatura Alta , Viabilidade Microbiana , Modelos Estatísticos , Salmonella , Teorema de Bayes , Contagem de Colônia Microbiana , Cinética , Salmonella/fisiologia
7.
PLoS One ; 16(5): e0243681, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33951039

RESUMO

Multi-drug resistant (MDR) non-typhoidal Salmonella (NTS) is a public health concern globally. This study reports the phenotypic and genotypic antimicrobial resistance (AMR) profiles of NTS isolates from bovine lymph nodes (n = 48) and ground beef (n = 29). Furthermore, we compared genotypic AMR data of our isolates with those of publicly available NTS genomes from Mexico (n = 2400). The probability of finding MDR isolates was higher in ground beef than in lymph nodes:χ2 = 12.0, P = 0.0005. The most common resistant phenotypes involved tetracycline (40.3%), carbenicillin (26.0%), amoxicillin-clavulanic acid (20.8%), chloramphenicol (19.5%) and trimethoprim-sulfamethoxazole (16.9%), while more than 55% of the isolates showed decreased susceptibility to ciprofloxacin and 26% were MDR. Conversely, resistance to cephalosporins and carbapenems was infrequent (0-9%). MDR phenotypes were strongly associated with NTS serovar (χ2 = 24.5, P<0.0001), with Typhimurium accounting for 40% of MDR strains. Most of these (9/10), carried Salmonella genomic island 1, which harbors a class-1 integron with multiple AMR genes (aadA2, blaCARB-2, floR, sul1, tetG) that confer a penta-resistant phenotype. MDR phenotypes were also associated with mutations in the ramR gene (χ2 = 17.7, P<0.0001). Among public NTS isolates from Mexico, those from cattle and poultry had the highest proportion of MDR genotypes. Our results suggest that attaining significant improvements in AMR meat safety requires the identification and removal (or treatment) of product harboring MDR NTS, instead of screening for Salmonella spp. or for isolates showing resistance to individual antibiotics. In that sense, massive integration of whole genome sequencing (WGS) technologies in AMR surveillance provides the shortest path to accomplish these goals.


Assuntos
Bovinos/microbiologia , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla , Genômica , Aves Domésticas/microbiologia , Salmonella/fisiologia , Animais , México , Salmonella/efeitos dos fármacos
8.
Nat Commun ; 12(1): 3218, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34050167

RESUMO

Cooperativity has a central place in biological regulation, providing robust and highly-sensitive regulation. The bacterial flagellar motor implements autonomous torque regulation based on the stator's dynamic structure; the stator units bind to and dissociate from the motor dynamically in response to environmental changes. However, the mechanism of this dynamic assembly is not fully understood. Here, we demonstrate the cooperativity in the stator assembly dynamics. The binding is slow at the stalled state, but externally forced rotation as well as driving by motor torque in either direction boosts the stator binding. Hence, once a stator unit binds, it drives the rotor and triggers the avalanche of succeeding bindings. This cooperative mechanism based on nonequilibrium allostery accords with the recently-proposed gear-type coupling between the rotor and stator.


Assuntos
Proteínas de Bactérias/metabolismo , Flagelos/metabolismo , Locomoção/fisiologia , Proteínas Motores Moleculares/metabolismo , Salmonella/fisiologia , Rotação
9.
Front Immunol ; 12: 648710, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868285

RESUMO

The global rise of antibiotic-resistant strains of Salmonella has necessitated the development of alternative therapeutic strategies. Recent studies have shown that targeting host factors may provide an alternative approach for the treatment of intracellular pathogens. Host-directed therapy (HDT) modulates host cellular factors that are essential to support the replication of the intracellular pathogens. In the current study, we identified Gefitinib as a potential host directed therapeutic drug against Salmonella. Further, using the proteome analysis of Salmonella-infected macrophages, we identified EGFR, a host factor, promoting intracellular survival of Salmonella via mTOR-HIF-1α axis. Blocking of EGFR, mTOR or HIF-1α inhibits the intracellular survival of Salmonella within the macrophages and in mice. Global proteo-metabolomics profiling indicated the upregulation of host factors predominantly associated with ATP turn over, glycolysis, urea cycle, which ultimately promote the activation of EGFR-HIF1α signaling upon infection. Importantly, inhibition of EGFR and HIF1α restored both proteomics and metabolomics changes caused by Salmonella infection. Taken together, this study identifies Gefitinib as a host directed drug that holds potential translational values against Salmonella infection and might be useful for the treatment of other intracellular infections.


Assuntos
Gefitinibe/farmacologia , Metabolômica/métodos , Proteômica/métodos , Infecções por Salmonella/prevenção & controle , Salmonella/efeitos dos fármacos , Animais , Células Cultivadas , Receptores ErbB/imunologia , Receptores ErbB/metabolismo , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/imunologia , Inibidores de Proteínas Quinases/farmacologia , Salmonella/imunologia , Salmonella/fisiologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Células THP-1
10.
Int J Food Microbiol ; 344: 109114, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33652336

RESUMO

Thermal inactivation kinetics of Salmonella in low moisture foods are necessary for developing proper thermal processing parameters for pasteurization. The effect of water activity on thermal inactivation kinetics of Salmonella and Enterococcus faecium NRRL B-2354 in ground black pepper has not been studied previously. Identification of a suitable surrogate assists in conducting in-plant process validations. Ground black pepper was inoculated with a 5-serotype Salmonella cocktail or E. faecium NRRL B-2354, equilibrated to water activities of 0.25, 0.45 or 0.65 in a humidity-controlled chamber, and isothermally treated at different temperatures. The survivor data were used for fitting the log-linear models to obtain the D and z-values of Salmonella and E. faecium in ground black pepper. Modified Bigelow models were developed to evaluate the effects of temperature and water activity on the thermal inactivation kinetics of Salmonella and E. faecium. Water activity and temperature showed significant negative effects on the thermal resistance of Salmonella and E. faecium in ground black pepper. For example, significantly higher D values of Salmonella were observed at water activity of 0.45 (D70°C = 20.5 min and D75°C = 7.8 min) compared to water activity of 0.65 (D70°C = 3.9 min and D75°C = 2.0 min). D-values of E. faecium were significantly higher than those of Salmonella at all three water activities, indicating that E. faecium is a suitable surrogate for Salmonella in thermal processing validation.


Assuntos
Enterococcus faecium/crescimento & desenvolvimento , Pasteurização/métodos , Piper nigrum/microbiologia , Salmonella/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Enterococcus faecium/classificação , Enterococcus faecium/fisiologia , Microbiologia de Alimentos , Temperatura Alta , Salmonella/fisiologia , Água/análise
11.
Proc Natl Acad Sci U S A ; 118(12)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33723050

RESUMO

Multiple gram-negative bacteria encode type III secretion systems (T3SS) that allow them to inject effector proteins directly into host cells to facilitate colonization. To be secreted, effector proteins must be at least partially unfolded to pass through the narrow needle-like channel (diameter <2 nm) of the T3SS. Fusion of effector proteins to tightly packed proteins-such as GFP, ubiquitin, or dihydrofolate reductase (DHFR)-impairs secretion and results in obstruction of the T3SS. Prior observation that unfolding can become rate-limiting for secretion has led to the model that T3SS effector proteins have low thermodynamic stability, facilitating their secretion. Here, we first show that the unfolding free energy ([Formula: see text]) of two Salmonella effector proteins, SptP and SopE2, are 6.9 and 6.0 kcal/mol, respectively, typical for globular proteins and similar to published [Formula: see text] for GFP, ubiquitin, and DHFR. Next, we mechanically unfolded individual SptP and SopE2 molecules by atomic force microscopy (AFM)-based force spectroscopy. SptP and SopE2 unfolded at low force (F unfold ≤ 17 pN at 100 nm/s), making them among the most mechanically labile proteins studied to date by AFM. Moreover, their mechanical compliance is large, as measured by the distance to the transition state (Δx ‡ = 1.6 and 1.5 nm for SptP and SopE2, respectively). In contrast, prior measurements of GFP, ubiquitin, and DHFR show them to be mechanically robust (F unfold > 80 pN) and brittle (Δx ‡ < 0.4 nm). These results suggest that effector protein unfolding by T3SS is a mechanical process and that mechanical lability facilitates efficient effector protein secretion.


Assuntos
Fenômenos Fisiológicos Bacterianos , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo III/metabolismo , Proteínas de Bactérias/química , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Negativas/ultraestrutura , Microscopia de Força Atômica , Estabilidade Proteica , Salmonella/fisiologia , Salmonella/ultraestrutura , Termodinâmica
13.
Food Microbiol ; 97: 103737, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33653516

RESUMO

The effect of ohmic heating (OH) (50, 55, and 60 °C, 6 V/cm) on the inactivation kinetics (Weibull model) and morphological changes (scanning electron microscopy and flow cytometry) of Salmonella spp. in infant formula (IF) was evaluated. In addition, thermal load indicators (hydroxymethylfurfural and whey protein nitrogen index, HMF, and WPNI) and bioactive compounds (DPPH, total phenolics, ACE, α-amylase, and α-glucosidase inhibitory activities) were also studied. OH presented a more intense inactivation rate than conventional heating, resulting in a reduction of about 5 log CFU per mL at 60 °C in only 2.91 min, being also noted a greater cell membrane deformation, higher formation of bioactive compounds, and lower values for the thermal load parameters. Overall, OH contributed to retaining the nutritional value and improve food safety in IF processing.


Assuntos
Conservação de Alimentos/métodos , Fórmulas Infantis/química , Fórmulas Infantis/microbiologia , Salmonella/crescimento & desenvolvimento , Microbiologia de Alimentos , Conservação de Alimentos/instrumentação , Furaldeído/análogos & derivados , Furaldeído/química , Temperatura Alta , Salmonella/química , Salmonella/fisiologia , Proteínas do Soro do Leite/química
14.
Nutrients ; 13(2)2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33525327

RESUMO

Non-typhoidal Salmonella (NTS) is one of the less focused on infections and is often associated with faulty child nutrition in the developing world. This study aimed to evaluate the association of NTS infection with growth faltering among children under the age of five. We analyzed data from 378 fecal NTS positive children with both moderate-to-severe diarrhea (MSD) and asymptomatic infection from the seven countries of South Asia and sub-Saharan Africa during enrolment and on day 60 follow up in the Global Enteric Multicenter Study (GEMS) for the period of December 2007 to March 2011. Children not associated with fecal NTS (n = 1134) were randomly selected from the same dataset (1:3 ratio) as a comparison group. The association between an explanatory variable and the outcome variable was longitudinally tested using generalized estimating equations (GEE), where the dependent variables were height-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ) z-score, and the independent variable was the presence of fecal NTS. The GEE multivariable model identified a negative association between fecal NTS and WAZ (coefficient: -0.19; 95% CI (confidence interval): -0.33, -0.04, and p value = 0.010), WHZ (coef: -0.19; 95% CI: -0.34, -0.05, and p value = 0.007), and HAZ (coef: -0.13; 95% CI: -0.27, -0.01, and p value = 0.073) after adjusting for age, gender, diarrhea, breastfeeding status, mothers' education, number of children under the age of five, household size by the number of people regularly sleep at the home, handwashing practice, source of drinking water, wealth index, presence of co-pathogens, comorbidity, and study sites. In the GEMS, where children were followed during 50-90 days of enrolment, the presence of fecal NTS harmed the child's anthropometric outcomes. Minimizing potential exposure to NTS is needed to curb worsening child undernutrition.


Assuntos
Desenvolvimento Infantil , Infecções por Salmonella/epidemiologia , Estatura , Peso Corporal , Pré-Escolar , Fezes/microbiologia , Feminino , Humanos , Masculino , Salmonella/fisiologia
15.
Vet Med Sci ; 7(3): 820-830, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33527778

RESUMO

Salmonellosis in poultry is an important disease that seriously impedes the development of the poultry industry. The increased resistance to antimicrobials against Salmonella has been a major public health concern worldwide. We conducted a study from January to June 2016 in and around the Rajshahi district of Bangladesh on the commercial chicken to isolate, identify and characterize poultry-specific Salmonella, to assess the potential risk factors and to determine the antimicrobial resistance pattern of the isolates. The overall prevalence of Salmonella enterica was 41% (49/120) [95% CI: 31.95%-50.17%] with 41.7% in broiler chicken (25/60) [95% CI: 29.06%-55.12%] and 40% in layer chicken (24/60, 40%) [95% CI: 27.56%-53.46%]. Samples collected from Rajshahi city (OR = 1.37, 95% CI: 0.50-3.73) and Puthia Upazila (OR = 1.51, 95% CI: 0.56-4.12) were more likely to be positive for Salmonella than Charghat Upazila. Salmonella detection was 1.3 times higher in chicken, providing loose feed than those provided ready feed. All the isolates fermented dextrose, maltose and mannitol with the production of acid and gas, but did not ferment sucrose and lactose. The isolates showed catalase, MR, citrate utilization test and TSI agar test positive, but indole and V-P tests negative. Salmonella isolates were sensitive to ciprofloxacin (90%), gentamycin (80%), amoxicillin (75%), streptomycin (70%), ampicillin (45%) and sulfamethoxazole-trimethoprim (45%), whereas highly resistant to penicillin (100%) and nalidixic acid (100%) followed by sulfamethoxazole-trimethoprim (55%), ampicillin (40%) and amoxicillin (25%). Salmonella enterica is endemic in commercial chicken production in Bangladesh with high prevalence. A considerable proportion of Salmonella isolates was found to be resistant to the majority of the common antimicrobial drugs. A good biosecurity system could be effective for the reduction of Salmonella. It is necessary to obtain universal commitments to establish prudent antibiotic use policies.


Assuntos
Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana/veterinária , Salmonella/fisiologia , Animais , Bangladesh/epidemiologia , Feminino , Masculino , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Prevalência , Salmonella/efeitos dos fármacos , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia
16.
Poult Sci ; 100(4): 100991, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33610890

RESUMO

Salmonella contamination sources and transmission routes were studied in 5 Belgian poultry slaughterhouses. Samples from the slaughter and cutting line after cleaning and disinfection were collected, as well as neck skin samples and thighs during slaughter of the first flock. In total, 680 swab and water samples were taken from the slaughter line before slaughter. In all slaughterhouses, Salmonella was notwithstanding cleaning and disinfection still isolated from the slaughter line before start of activities. The prevalence of Salmonella in the plucking area was 10.4% (38/365) (hanging area: 5.0%, scalding tank: 5.8%, plucking machine: 17.0%); in the evisceration room, 1.5% (2/138); and in the cutting area, 2.0% (3/149). No Salmonella (0/28) was found in samples from the chilling line. On neck skin samples taken from the various lines, Salmonella prevalence was 16.1% (48/299) after plucking, 16.0% (48/300) after evisceration, 23.3% (70/300) after chilling; on thighs, prevalence was 10.0% (24/240). Nine Salmonella serotypes were identified of which Salmonella Infantis was the most common serovar (53.8%), especially in slaughterhouse A. Two contamination causes were identified; first, although all flocks had an official Salmonella negative status, this was in one case incorrect and led to an enormous contamination of the neck skins of the flock and the slaughterline (i.e., cooling water). Second, molecular typing revealed cross-contamination from flocks slaughtered 1 d before sampling. Salmonella was apparently not always eliminated by the cleaning and disinfection process and able to contaminate the carcasses of the first slaughtered flock. In conclusion, the results of this study provided practical insights for poultry production to further improve their Salmonella control, for example, Salmonella status determination closer to the slaughter date, to adapt cleaning and disinfection protocols especially for critical machinery and better hygienic designed equipment.


Assuntos
Matadouros , Indústria Alimentícia , Aves Domésticas , Salmonella , Matadouros/estatística & dados numéricos , Animais , Galinhas , Indústria Alimentícia/normas , Indústria Alimentícia/estatística & dados numéricos , Microbiologia de Alimentos/estatística & dados numéricos , Prevalência , Salmonella/isolamento & purificação , Salmonella/fisiologia
17.
Food Microbiol ; 95: 103680, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33397612

RESUMO

The innate and inducible resistance of six Salmonella strains (4/74, FS8, FS115, P167807, ATCC 13076, WT) in mayonnaise at 5 °C following adaptation to different pH/undissociated acetic acid (UAA) combinations (15mM/pH5.0, 35mM/pH5.5, 45mM/pH6.0) was investigated. The inherent and acid-induced responses were strain-dependent. Two strains (ATCC 13076, WT), albeit not the most resistant innately, exhibited the most prominent adaptive potential. Limited/no adaptability was observed regarding the rest strains, though being more resistant inherently. The individual effect of pH and UAA adaptation in the phenotypic and transcriptomic profiles of ATCC 13076 and WT was further examined. The type (pH, UAA) and magnitude of stress intensity affected their responses. Variations in the type and magnitude of stress intensity also determined the relative gene expression of four genes (adiA, cadB, rpoS, ompR) implicated in Salmonella acid resistance mechanisms. adiA and cadB were overexpressed following adaptation to some treatments; rpoS and ompR were downregulated following adaptation to 15mM/pH5.0 and 35mM/pH5.5, respectively. Nonetheless, the transcriptomic profiles did not always correlate with the corresponding phenotypes. In conclusion, strain variations in Salmonella are extensive. The ability of the strains to adapt and induce resistant phenotypes and acid resistance-related genes is affected by the type and magnitude of the stress applied during adaptation.


Assuntos
Ácido Acético/metabolismo , Condimentos/microbiologia , Salmonella/fisiologia , Ácido Acético/química , Adaptação Fisiológica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Condimentos/análise , Microbiologia de Alimentos , Armazenamento de Alimentos , Concentração de Íons de Hidrogênio , Refrigeração , Salmonella/genética
18.
PLoS Negl Trop Dis ; 15(1): e0009052, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33471793

RESUMO

Intestinal helminth infection can impair host resistance to co-infection with enteric bacterial pathogens. However, it is not known whether helminth drug-clearance can restore host resistance to bacterial infection. Using a mouse helminth-Salmonella co-infection system, we show that anthelmintic treatment prior to Salmonella challenge is sufficient to restore host resistance to Salmonella. The presence of the small intestine-dwelling helminth Heligmosomoides polygyrus at the point of Salmonella infection supports the initial establishment of Salmonella in the small intestinal lumen. Interestingly, if helminth drug-clearance is delayed until Salmonella has already established in the small intestinal lumen, anthelmintic treatment does not result in complete clearance of Salmonella. This suggests that while the presence of helminths supports initial Salmonella colonization, helminths are dispensable for Salmonella persistence in the host small intestine. These data contribute to the mechanistic understanding of how an ongoing or prior helminth infection can affect pathogenic bacterial colonization and persistence in the mammalian intestine.


Assuntos
Coinfecção/microbiologia , Coinfecção/parasitologia , Resistência à Doença/fisiologia , Helmintíase/complicações , Enteropatias Parasitárias/complicações , Nematospiroides dubius/fisiologia , Salmonella/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Microbioma Gastrointestinal , Intestinos/microbiologia , Intestinos/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Infecções por Salmonella/complicações , Salmonella typhi
19.
Nat Commun ; 12(1): 261, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431850

RESUMO

Intestinal microfold cells are the primary pathway for translocation of secretory IgA (SIgA)-pathogen complexes to gut-associated lymphoid tissue. Uptake of SIgA/commensals complexes is important for priming adaptive immunity in the mucosa. This study aims to explore the effect of SIgA retrograde transport of immune complexes in Crohn's disease (CD). Here we report a significant increase of SIgA transport in CD patients with NOD2-mutation compared to CD patients without NOD2 mutation and/or healthy individuals. NOD2 has an effect in the IgA transport through human and mouse M cells by downregulating Dectin-1 and Siglec-5 expression, two receptors involved in retrograde transport. These findings define a mechanism of NOD2-mediated regulation of mucosal responses to intestinal microbiota, which is involved in CD intestinal inflammation and dysbiosis.


Assuntos
Doença de Crohn/metabolismo , Imunoglobulina A Secretora/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Animais , Colite/microbiologia , Colite/patologia , Doença de Crohn/patologia , Humanos , Lectinas Tipo C/metabolismo , Camundongos Knockout , Modelos Biológicos , Mutação/genética , Proteína Adaptadora de Sinalização NOD2/deficiência , Proteína Adaptadora de Sinalização NOD2/genética , Nódulos Linfáticos Agregados/metabolismo , Transporte Proteico , Salmonella/fisiologia , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Transcitose
20.
Int J Food Microbiol ; 337: 108950, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33212341

RESUMO

Foodborne pathogens such as Salmonella can endure dry environments of milk powders for extended periods due to the increased adaptability at a low water activity (aw) and proliferate when powders are hydrated. This study compared the survivability and the thermal resistance of a 5-serovar Salmonella cocktail in dry and hydrated nonfat dry milk (NFDM) and whole milk powder (WMP) stored for 180 days at ambient temperature (~20 °C). This study was designed as two factorial (storage days and milk powder type) randomized complete block design with three replications as blocks. The milk powders were spray inoculated with 5-serovar Salmonella cocktail and dried back to the original pre-inoculation aw. The D-values of Salmonella in inoculated NFDM and WMP were determined periodically (every 30 days, starting from day one). The milk powders were also individually hydrated on each analysis day to determine D- and z-values of Salmonella in hydrated powders. The D-values were determined using thermal-death-time disks and hot-water baths at 80, 85 and 90 °C for milk powders, and 59, 62 and 65 °C for hydrated powders. The D- and z-values of Salmonella at specific temperatures within dry or hydrated powders during the storage period were compared at P ≤ 0.05 using two-way ANOVA and Tukey's Test. The D-values of Salmonella in WMP on day 1 were 18.9, 9.9 and 4.4 min at 80, 85 and 90 °C, respectively, which increased to 29.4, 13.6 and 6.5 min at 80, 85 and 90 °C, respectively, on day 180. Whereas, D-values of Salmonella in NFDM on day 1 were 17.9, 9.2 and 4.4 min at 80, 85 and 90 °C, respectively, and stayed similar during the storage. The D-values of Salmonella in milk powder remained similar throughout the storage once hydrated. The overall z-value of Salmonella in NFDM and WMP was 16.3 °C, whereas in hydrated NFDM and WMP, the overall z-value was 6.4 °C.


Assuntos
Armazenamento de Alimentos , Alimentos em Conserva/microbiologia , Leite/microbiologia , Salmonella/fisiologia , Água/análise , Animais , Microbiologia de Alimentos , Temperatura Alta , Viabilidade Microbiana , Leite/química , Pós , Água/metabolismo
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