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1.
PLoS One ; 15(8): e0237541, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32834007

RESUMO

There is growing interest in exploring the chickens' intestinal microbiota and understanding its interactions with the host. The objective is to optimize this parameter in order to increase the productivity of farm animals. With the goal to isolate candidate probiotic strains, specific culturomic methods were used in our study to culture commensal bacteria from 7-days old chicks raised in two farms presenting long history of high performance. A total of 347 isolates were cultured, corresponding to at least 64 species. Among the isolates affiliated to the Firmicutes, 26 had less than 97% identity of their partial 16S sequence with that of the closest described species, while one presented less than 93% identity, thus revealing a significant potential for new species in this ecosystem. In parallel, and in order to better understand the differences between the microbiota of high-performing and low-performing animals, caecal contents of animals collected from these two farms and from a third farm with long history of low performance were collected and sequenced. This compositional analysis revealed an enrichment of Faecalibacterium-and Campylobacter-related sequences in lower-performing animals whereas there was a higher abundance of enterobacteria-related sequences in high-performing animals. We then investigated antibiosis activity against C. jejuni ATCC 700819 and C. jejuni field isolate as a first phenotypic trait to select probiotic candidates. Antibiosis was found to be limited to a few strains, including several lactic acid bacteria, a strain of Bacillus horneckiae and a strain of Escherichia coli. The antagonist activity depended on test conditions that mimicked the evolution of the intestinal environment of the chicken during its lifetime, i.e. temperature (37°C or 42°C) and oxygen levels (aerobic or anaerobic conditions). This should be taken into account according to the stage of development of the animal at which administration of the active strain is envisaged.


Assuntos
Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , Campylobacter/isolamento & purificação , Ceco/microbiologia , Galinhas/microbiologia , Microbioma Gastrointestinal , Doenças das Aves Domésticas/epidemiologia , Envelhecimento , Animais , Campylobacter/genética , Técnicas de Cultura de Células/métodos , Fazendas , Doenças das Aves Domésticas/microbiologia
2.
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
3.
Int J Food Microbiol ; 327: 108656, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32445835

RESUMO

Campylobacter is the world's leading cause of bacterial gastroenteritis, causing nearly 9 million cases of food poisoning in Europe every year. Poultry is considered the main source of Campylobacter infection to humans. The objectives of the study were to determine occurrence of C. jejuni and C. coli in chickens, the antimicrobial resistance, genotypes, and relatedness of the isolates. A total of 177 chicken samples obtained from informal butcher shops (fresh), formal poultry slaughterhouses (refrigerated) and retail market (frozen) were analyzed. Isolation of Campylobacter spp. was conducted according to the ISO 10272-2006 method. Multiplex PCR was used for confirmation and identification of the isolates. The disk diffusion method was used to determine the antimicrobial resistance of the isolates and multilocus sequence typing was used for genotyping. The proportion of samples with Campylobacter spp. was 31.6% among all chicken samples (fresh and refrigerated 47.5%, frozen 0%) C. coli was isolated from 42.4% of chicken samples obtained from butcher shops and from 18.6% of samples obtained in formal slaughterhouses. C. jejuni was isolated from 17.0% of samples obtained in butcher shops and formal slaughterhouses. Campylobacter spp. was not isolated in frozen chicken samples. All tested isolates showed resistance toward ciprofloxacin and susceptibility toward imipenem and all of the isolates were multidrug resistant toward 5 or more antimicrobials. Three sequence types were identified among 10 C. coli isolates and seven sequence types were identified among 10 C. jejuni isolates. Among sequence types, chicken isolates shared similarities of both phenotypic and genetic levels.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter coli , Campylobacter jejuni , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Matadouros , Animais , Antibacterianos/farmacologia , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter coli/efeitos dos fármacos , Campylobacter coli/genética , Campylobacter coli/isolamento & purificação , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Galinhas/microbiologia , Resistência Microbiana a Medicamentos , Doenças Transmitidas por Alimentos/microbiologia , Genótipo , Humanos , Jordânia/epidemiologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase Multiplex , Aves Domésticas/microbiologia , Prevalência
4.
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
5.
Vet Immunol Immunopathol ; 224: 110059, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32408182

RESUMO

There are currently no licensed vaccines against Clostridium perfringens which causes necrotic enteritis in poultry. Chitosan nanoparticles were formulated with native (CN) or toxoids (CT) of extracellular proteins (ECP) of C. perfringens, both surface-tagged with Salmonella flagellar proteins. In a pH stability assay, CN and CT nanoparticles released 6% and 0% of their protein at 8.0 pH. In a protein release assay, CN and CT nanoparticles released 16% and 10% of their protein respectively at 7.4 pH after 24 h. CN and CT nanoparticles incubated at 100 µg/mL PBS with Chicken RBCs released 1% and 0% hemoglobin respectively. Ninety broilers were randomly assigned to treatments; sham-vaccinated (Control), CN-vaccinated (CN), and CT-vaccinated (CT). Each bird was orally gavaged with 50 µg vaccine in 0.5 mL PBS or 0.5 mL PBS only on d 0, 3, 7 and 14 of age. At 21 d of age, the CN group had higher anti-ECP IgA than control (P < 0.05). At 21 d of age, the CN and CT group had higher anti-ECP IgA than control (P < 0.05). At 17 d of age, the CN group had higher anti-flagellar IgG than control (P < 0.05). At 10 d of age, the CN group had higher anti-flagellar IgA than control (P < 0.05). Splenic T cells from chickens in the CN and CT group ex-vivo stimulated with 0.05 mg/mL ECP, had higher proliferation control (P < 0.05, P < 0.01 respectively). Splenic T cells from chickens in the CN and CT groups ex-vivo stimulated with 0.1 mg/mL ECP had proliferation than control (P < 0.05). Pooled serum from 17 d of age CN and CT-vaccinated birds partially neutralized toxins in 50 µg of ECP (P < 0.05). Pooled serum from 28 d of age CN-vaccinated birds also partially neutralized toxins in 50 µg of ECP. The result from this study indicates the potential for chitosan loaded with Clostridium perfringens extracellular proteins to be applied to necrotic enteritis challenge studies.


Assuntos
Vacinas Bacterianas/imunologia , Quitosana/química , Infecções por Clostridium/veterinária , Enterocolite Necrosante/veterinária , Nanopartículas/química , Administração Oral , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Neutralizantes/sangue , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Galinhas/imunologia , Galinhas/microbiologia , Infecções por Clostridium/imunologia , Infecções por Clostridium/prevenção & controle , Clostridium perfringens , Enterocolite Necrosante/imunologia , Enterocolite Necrosante/prevenção & controle , Flagelos/imunologia , Imunogenicidade da Vacina , Imunoglobulina A/análise , Imunoglobulina G/sangue , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Salmonella , Vacinas Atenuadas/imunologia
6.
PLoS One ; 15(4): e0232088, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32324793

RESUMO

Salmonella Enteritidis (SE) has been the most common Salmonella serotype associated with foodborne infections in the last several years. Dietary applications of yeast-based preparations in feed have shown to reduce Salmonella colonization in chickens augmenting SE control strategies. This study was conducted to evaluate the effects of a mannan-rich yeast cell wall-derived preparation (Actigen®) administered in feed at a rate of 400 g/ton on SE colonization in the cecum and internal organs of commercial layer chickens. Sixteen week-old layer pullets were orally challenged with a selected nalidixic acid resistant SE strain at a dose of 1.7×10^9 colony forming units (CFU) per bird. SE colonization was assessed by evaluating isolation rates from ovary and pooled liver/spleen samples as well as enumeration of SE in cecal pouches one week post-challenge. Recovery rates of SE from the ovaries of directly challenged birds receiving Actigen® were significantly lower (P <0.02) than those in directly challenged birds fed an unsupplemented control diet. Recovery rates of SE from pooled liver/spleen samples were not significantly different between Actigen®-treated pullets and controls (P = 0.22). Using direct plate count methods, cecal SE concentrations were 1 log10 lower (P <0.001) in challenged pullets in the Actigen®-supplemented group than in the challenged controls. The SE concentration distributions in the ceca were similar in groups testing positive and groups testing negative for SE in the ovaries and liver/spleens tissues. As a result, SE concentrations in the ceca could not be directly related to the occurrence or prevalence of SE in these tissues. In conclusion, Actigen® supplementation appears to decrease the prevalence of SE in ovarian tissue and concentrations of SE in cecal contents and may be useful as a tool for reducing the risk of eggshell contamination and transovarian transmission of SE in eggs.


Assuntos
Ceco/microbiologia , Mananas/farmacologia , Ovário/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Salmonella enteritidis/efeitos dos fármacos , Ração Animal , Animais , Ceco/efeitos dos fármacos , Parede Celular/metabolismo , Galinhas , Suplementos Nutricionais , Feminino , Ovário/microbiologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Prevalência , Salmonelose Animal/epidemiologia , Salmonelose Animal/prevenção & controle
7.
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
8.
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
9.
PLoS One ; 15(3): e0230676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231395

RESUMO

Salmonella Heidelberg is commonly reported in foodborne outbreaks around the world, and chickens and poultry products are known as important source of these pathogen. Multidrug-resistant S. Heidelberg strains are disseminated into poultry production chair, which can lead to severe clinical infections in humans and of difficult to treat. This study aimed at evaluating the ß-lactam susceptibility and genotypic relatedness of Salmonella Heidelberg at Brazilian poultry production chain. Sixty-two S. Heidelberg strains from poultry production chain (poultry, poultry meat and poultry farm) were used. All strains were evaluated to antimicrobial susceptibility by diffusion disk test, as well as ß-lactam resistance genes. Genotypic relatedness was assessed by Pulsed-Field Gel Eletrophoresis, using Xba1 restriction enzyme. Forty-one strains were characterized as multidrug-resistant according to phenotype characterization. The resistance susceptibility revealed 31 distinct profiles, with higher prevalence of streptomycin (61/62), nalidixic acid (50/62), tetracycline (43/62) and ß-lactam drugs (37/62). blaCMY-2 was the more frequent ß-lactamase gene found (38/62); other resistance genes found were blaCTX-M (2/62), blaSHV (3/62) and blaTEM-1 (38/62). No carbapenemase genes was found. The Pulsed-Field Gel Electrophoresis showed 58 different profiles. Strains with a larger number of antimicrobial resistance were grouped into ten major clusters apart from others. The spread of resistance by ampC continues to rise, thereby turning concern to public health, since the ß-lactam antimicrobials are used as a therapeutic treatment in humans.


Assuntos
Farmacorresistência Bacteriana Múltipla , Doenças das Aves Domésticas/microbiologia , Salmonella/enzimologia , beta-Lactamases/genética , Animais , Antibacterianos/farmacologia , Brasil , Galinhas , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genótipo , Testes de Sensibilidade Microbiana , Ácido Nalidíxico/farmacologia , Doenças das Aves Domésticas/patologia , Salmonella/efeitos dos fármacos , Salmonella/genética , Salmonella/isolamento & purificação , Estreptomicina/farmacologia , beta-Lactamases/metabolismo , beta-Lactamas/farmacologia
10.
Res Vet Sci ; 131: 24-30, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278961

RESUMO

Two-component systems (TCSs) are widespread regulatory systems which can help bacteria to control their cellular functions and respond to a diverse range of stimuli. The KdpD/KdpE system had been well studied for regulating potassium transport and identified as an adaptive regulator involved in the virulence of some pathogenic bacteria, but its role in avian pathogenic Escherichia coli (APEC) was still unknown. In this study, the mutant strain AE17ΔKdpDE was obtained successfully of a clinical APEC isolation AE17 using the lambda Red recombinase system and performed the transcriptional sequencing of the wild type strain AE17 and the mutant strain AE17ΔKdpDE. The transcriptional sequencing results revealed that the KdpD/KdpE two-component system mainly influenced the expression of the genes covering metabolic pathways, flagellar assembly, global transcription regulator. The expression of some flagellar-related genes detecting by quantitative real-time PCR was consistent with the results of transcriptional sequencing. Importantly, fewer flagellum of the mutant strain AE17ΔKdpDE was observed than AE17 using the transmission electron microscope and a decreased motility circle of AE17ΔKdpDE appeared in the semisolid medium. In addition, the serum bactericidal assay was carried out with the specific-pathogen-free chicken in different dilution and the survival ability in the serum of AE17ΔKdpDE was also obviously lower than that of AE17. These results suggested that in APEC, the KdpD/KdpE two-component system mainly influenced the expression of flagella-related genes, the flagellum formation, the motility and antiserum bactericidal activity.


Assuntos
Galinhas/microbiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/patogenicidade , Proteínas Quinases/metabolismo , Transativadores/metabolismo , Animais , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Feminino , Doenças das Aves Domésticas/microbiologia , Proteínas Quinases/genética , Transativadores/genética , Virulência
11.
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
12.
Poult Sci ; 99(3): 1615-1617, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32111328

RESUMO

Before starting a study with many birds, it helps to know the method of chick inoculation. The objective was to compare 3 methods of Salmonella challenge (oral gavage [OR], intracloacal inoculation [IC], and seeder bird [SB]). Day-old broiler chicks (n = 100) were inoculated with 106 colony forming units (CFU) per chick of a marker strain of Salmonella Heidelberg (SH) with each route of inoculation. Chicks (n = 25) inoculated by each route were placed in floor pens on fresh pine shavings litter. For the seeder batch, 5 colonized chicks, each orally gavaged with 106 CFUs, were placed with 20 pen mates. Two weeks after inoculation, 10 birds from each pen and the 5 inoculated seeder birds were euthanized, the ceca were aseptically removed and macerated with a rubber mallet and weighed, and 3 times (w/v) buffered peptone was added and stomached for 60 s. Serial dilutions were made and plated onto Brilliant Green Sulfa plates containing 200 ppm nalidixic acid. Plates were incubated along with the stomached ceca for 24 h at 37°C. If no colonies appeared on the plates, an additional plate was streaked from the preenriched bag and incubated for 24 h at 37°C. In addition to all seeder birds being positive, the number of SH-positive birds out of 20 sampled in each group was 13, 17, and 7 for OR, IC, and SB, respectively. The level of SH per g of ceca and cecal contents was log (SE) 3.0 (0.7), 2.0 (0.4), and 2.6 (0.4) for OR, IC, and SB, respectively. After enrichment, the number of colonized birds out of 20 was 18, 20, and 10 for OR, IC, and SB, respectively. In conclusion, this study suggests that IC is the method to use to ensure most of the challenged birds are colonized. However, if you prefer to have a smaller percentage of the birds colonized with higher levels, then OR might be better.


Assuntos
Galinhas/microbiologia , Salmonelose Animal/transmissão , Salmonella enterica/fisiologia , Administração Oral , Animais , Animais Recém-Nascidos/microbiologia , Ceco/microbiologia , Cloaca/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonella enterica/crescimento & desenvolvimento
13.
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
14.
Pol J Microbiol ; 69(1): 5-18, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32189480

RESUMO

Probiotics are considered an alternative to antibiotics in the prevention and treatment of Salmonella diseases in poultry. However, to use probiotics as proposed above, it is necessary to evaluate their properties in detail and to select the most effective bacterial strains in the application targeted. In this study, probiotic properties of new Lactobacillus sp. strains were investigated and their antimicrobial activity against 125 environmental strains of Salmonella sp. was determined using the agar slab method. Furthermore, their survival in the presence of bile salts and at low pH, antibiotics susceptibility, aggregation and coaggregation ability, adherence to polystyrene and Caco-2 cells, and cytotoxicity were investigated. Each strain tested showed antagonistic activity against at least 96% of the environmental Salmonella sp. strains and thus representing a highly epidemiologically differentiated collection of poultry isolates. In addition, the probiotic properties of new Lactobacillus strains are promising. Therefore, all strains examined showed a high potential for use in poultry against salmonellosis.Probiotics are considered an alternative to antibiotics in the prevention and treatment of Salmonella diseases in poultry. However, to use probiotics as proposed above, it is necessary to evaluate their properties in detail and to select the most effective bacterial strains in the application targeted. In this study, probiotic properties of new Lactobacillus sp. strains were investigated and their antimicrobial activity against 125 environmental strains of Salmonella sp. was determined using the agar slab method. Furthermore, their survival in the presence of bile salts and at low pH, antibiotics susceptibility, aggregation and coaggregation ability, adherence to polystyrene and Caco-2 cells, and cytotoxicity were investigated. Each strain tested showed antagonistic activity against at least 96% of the environmental Salmonella sp. strains and thus representing a highly epidemiologically differentiated collection of poultry isolates. In addition, the probiotic properties of new Lactobacillus strains are promising. Therefore, all strains examined showed a high potential for use in poultry against salmonellosis.


Assuntos
Antibiose , Lactobacillus/fisiologia , Doenças das Aves Domésticas/prevenção & controle , Probióticos/administração & dosagem , Salmonelose Animal/prevenção & controle , Salmonella/patogenicidade , Animais , Aderência Bacteriana , Células CACO-2 , Humanos , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/microbiologia
15.
Infect Immun ; 88(5)2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32122943

RESUMO

Mycoplasma gallisepticum is the primary etiological agent of chronic respiratory disease in chickens. Live attenuated vaccines are most commonly used in the field to control the disease, but current vaccines have some limitations. Vaxsafe MG (strain ts-304) is a new vaccine candidate that is efficacious at a lower dose than the current commercial vaccine strain ts-11, from which it is derived. In this study, the transcriptional profiles of the trachea of unvaccinated chickens and chickens vaccinated with strain ts-304 were compared 2 weeks after challenge with M. gallisepticum strain Ap3AS during the chronic stage of infection. After challenge, genes, gene ontologies, pathways, and protein classes involved in inflammation, cytokine production and signaling, and cell proliferation were upregulated, while those involved in formation and motor movement of cilia, formation of intercellular junctional complexes, and formation of the cytoskeleton were downregulated in the unvaccinated birds compared to the vaccinated birds, reflecting immune dysregulation and the pathological changes induced in the trachea by infection with M. gallisepticum Vaccination appears to protect the structural and functional integrity of the tracheal mucosa 2 weeks after infection with M. gallisepticum.


Assuntos
Galinhas/imunologia , Galinhas/microbiologia , Mycoplasma gallisepticum/imunologia , Traqueia/imunologia , Traqueia/microbiologia , Transcrição Genética/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/imunologia , Proliferação de Células/fisiologia , Membrana Mucosa/imunologia , Membrana Mucosa/microbiologia , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/microbiologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/microbiologia , Regulação para Cima/imunologia , Vacinação/métodos , Vacinas Atenuadas/imunologia
16.
Res Vet Sci ; 130: 144-152, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32179292

RESUMO

Avian pathogenic Escherichia coli (APEC) can lead to extraintestinal disease in avian species via respiratory tract infection. However, the regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium remains unknown. In this study, we examined pathological changes in chicken trachea at different infection times (4, 8, 12 and 24 h). The RNA sequencing of APEC infection group and the PBS group (negative control) of chicken trachea epithelium were analysed. Our studies revealed that the oedema, heterophil infiltration and hyperaemia appeared at 8 and 12 h post APEC infection. And the hyperaemia phenomenon and heterophilic granulocyte infiltration disappeared at 24 h post infection. Then RNA sequencing showed many genes were dynamically expressed in the APEC infection group. At 4, 8 and 12 h post infection, the mRNA of differentially expressed genes were enriched by cytokine-cytokine receptor interaction and the toll-like receptor signalling pathway. The cell cycle pathway was enriched at 24 h post infection. Altogether, these findings suggest that APEC infection induces pathological change in the chicken trachea, the mRNA of differentially expressed genes participating in inflammation and hyperplasia signalling pathways. Which not only provide more evidence for regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium, but also facilitate the effective management of APEC infections in poultry through trachea.


Assuntos
Proteínas Aviárias/metabolismo , Galinhas , Citocinas/metabolismo , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/patologia , Receptores de Citocinas/metabolismo , Doenças da Traqueia/veterinária , Animais , Ciclo Celular , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/fisiopatologia , Feminino , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/fisiopatologia , RNA Mensageiro/metabolismo , Traqueia/patologia , Traqueia/fisiopatologia , Doenças da Traqueia/microbiologia , Doenças da Traqueia/patologia , Doenças da Traqueia/fisiopatologia
17.
Vet Res ; 51(1): 34, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32138776

RESUMO

Akkermansia muciniphila, a novel mucin-degrading bacterium, has been demonstrated to prevent the development of obesity and related complications. However, whether it can protect poultry from intestinal mucosal damage by enteropathogens has never been mentioned. In this study, we found that A. muciniphila colonized in the intestine and then relieved intestinal mucosal damage in chicks caused by S. pullorum, including anatomical and morphological damage, alleviation of body weight and intestinal inflammation. The repair process activated by A. muciniphila is accompanied by an increase in the number of goblet cells in the chick's intestine and an up-regulation of Mucin 2 and trefoil factor 2 (Tff2). In addition, we also demonstrate that A. muciniphila improved colon length, crypt depth, increased the proliferating cell nuclear antigen, with the accelerated proliferation of intestinal epithelium through Wnt/ß-catenin signaling pathway, thereby restoring the damaged intestinal mucosa. This study suggests that A. muciniphila activates the proliferation of intestinal cells protecting the intestinal barrier, thus relieving infection with S. pullorum in chickens.


Assuntos
Mucosa Intestinal/patologia , Doenças das Aves Domésticas/tratamento farmacológico , Probióticos/farmacologia , Salmonella/fisiologia , Verrucomicrobia/química , Animais , Proliferação de Células/efeitos dos fármacos , Galinhas , Mucosa Intestinal/microbiologia , Doenças das Aves Domésticas/microbiologia , Via de Sinalização Wnt/efeitos dos fármacos
18.
Vet Res ; 51(1): 40, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32156313

RESUMO

GtxA, a leukotoxic RTX-toxin, has been proposed a main virulence factor of Gallibacterium anatis. To evaluate the impact of GtxA during infection, we experimentally infected laying hens with a G. anatis wild-type (WT) strain and its isogenic gtxA deletion mutant (ΔgtxA), respectively, and monitored the birds during a 6 day period. Birds inoculated with ΔgtxA had significantly reduced gross lesions and microscopic changes compared to the birds inoculated with the WT strain. To assess the host response further, we quantified the expression of pro-inflammatory cytokines and apoptosis genes by RT-qPCR. In the ovarian tissue, the expression levels of IL-4 and TNF-α were significantly lower in the ΔgtxA group compared to the WT group, while IL-6 and IL-10 levels appeared similar in the two groups. In the spleen tissue of ΔgtxA infected chickens, IL-4 expression was also lower compared to the WT infected chickens. The results indicated that GtxA plays a key role in an acute cytokine-mediated Th2-like response against G. anatis infection in the ovary tissue. The pro-inflammatory response in the ovary tissue of birds inoculated with ΔgtxA mutant was thus significantly lower than the wild-type response. This was, at least partly, supported by the apoptosis gene expression levels, which were significantly higher in the ΔgtxA mutant compared to the wild-type infected chickens. In conclusion, GtxA clearly plays an important role in the pathogenesis of G. anatis infections in laying hens. Further investigations into the specific factors regulating the host response is however needed to provide a more complete understanding of the bacteria-host interaction.


Assuntos
Proteínas de Bactérias/genética , Galinhas , Infecções por Pasteurellaceae/veterinária , Pasteurellaceae/patogenicidade , Doenças das Aves Domésticas/microbiologia , Fatores de Virulência/genética , Animais , Proteínas de Bactérias/metabolismo , Feminino , Pasteurellaceae/genética , Pasteurellaceae/fisiologia , Infecções por Pasteurellaceae/microbiologia , Fatores de Virulência/metabolismo
19.
Poult Sci ; 99(2): 1088-1095, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32029145

RESUMO

Avian pathogenic Escherichia coli (APEC) causes extensive mortality in poultry flocks, leading to extensive economic losses. The aim of this study was to investigate the phenotypic and genotypic characteristics and antimicrobial resistance of recent APEC isolates. Of the 79 APEC isolates, the most predominant serogroup was O78 (16 isolates, 20.3%), followed by O2 (7 isolates, 8.9%) and O53 (7 isolates, 8.9%). Thirty-seven (46.8%) and six (7.6%) of the isolates belonged to phylogenetic groups D and B2, respectively, and presented as virulent extraintestinal E. coli. Among 5 analyzed virulence genes, the highest frequency was observed in hlyF (74 isolates, 93.7%), followed by iutA (72 isolates, 91.9%) gene. The distribution of the iss gene was significantly different between groups A/B1 and B2/D (P < 0.05). All group B2 isolates carried all 5 virulence genes. APEC isolates showed high resistance to ampicillin (83.5%), nalidixic acid (65.8%), tetracycline (64.6%), cephalothin (46.8%), and ciprofloxacin (46.8%). The ß-lactamases-encoding genes blaTEM-1 (23 isolates, 29.1%), blaCTX-M-1 (4 isolates, 5.1%), and blaCTX-M-15 (3 isolates, 3.8%); the aminoglycoside-modifying enzyme gene aac(3)-II (4 isolates, 5.1%); and the plasmid-mediated quinolone genes qnrA (10 isolates, 12.7%) and qnrS (2 isolates, 2.5%) were identified in APEC isolates. The tetA (37 isolates, 46.8%) and sul2 (20 isolates, 25.3%) were the most prevalent among tetracycline and sulfonamide resistant isolates, respectively. This study indicates that APEC isolates harbor a variety of virulence and resistance genes; such genes are often associated with plasmids that facilitate their transmission between bacteria and should be continuously monitored to track APEC transmission in poultry farms.


Assuntos
Galinhas , Resistência Microbiana a Medicamentos/genética , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Doenças das Aves Domésticas/microbiologia , Animais , Escherichia coli/genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Genótipo , Fenótipo , República da Coreia , Virulência
20.
Poult Sci ; 99(2): 1117-1123, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32029147

RESUMO

Colibacillosis, caused by Escherichia coli, is one of the most common bacterial diseases of chickens. The high incidence and considerable economic losses associated with colibacillosis make it a significant concern worldwide. In recent years, the efficacy of colistin has been severely impacted by the emergence of plasmid-mediated colistin resistance genes, especially mcr-1. Therefore, monitoring of antibiotic resistance, particularly colistin resistance, amongst E. coli strains is vitally important to the future growth and sustainability of the poultry industry. In this study, a total of 130 E. coli strains were isolated from the livers of chickens displaying symptoms of colibacillosis in Tai'an, China. Isolates were screened for their susceptibility to various antibiotics and for the presence of mobile colistin resistance genes and other antibiotic resistance genes. Overall, 75 (57.7%) isolates showed resistance to colistin and were positive for mcr-1. The mobile colistin resistance genes, mcr-2, -3, and -4, were not detected in this study. Of the 75 mcr-1-positive isolates, all (100%) also carried tetracycline resistance genes, 71 (94.7%) also contained genes associated with ß-lactam resistance, 59 (78.7%) contained aminoglycoside resistance genes, and 57 (76%) contained sulfonamide resistance genes. This high prevalence of multidrug resistance among mcr-1-positive E. coli isolates, including the production of extended-spectrum ß-lactamases, is highly concerning. The surveillance findings presented here will be conducive to our understanding of the prevalence and characteristics of multidrug-resistance in E. coli in the Tai'an area and will provide a better scientific basis for the clinical treatment of colibacillosis in chickens.


Assuntos
Galinhas , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Doenças das Aves Domésticas/epidemiologia , Animais , China/epidemiologia , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Testes de Sensibilidade Microbiana/veterinária , Doenças das Aves Domésticas/microbiologia , Prevalência
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