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1.
Equine Vet J ; 52(1): 98-103, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30991461

RESUMO

BACKGROUND: Salmonella enterica subsp. enterica serovar Abortusequi (S. Abortusequi) is a serotype restricted to equines, which produces abortion outbreaks. Nowadays the disease is being reported in different countries including Argentina thus generating an important impact in the equine industry. Molecular characterization of the 95 kb virulence plasmid and the spvC gene of S. Abortusequi demonstrated their importance in the pathogenicity of the serotype. In the last decades, high clonality of S. Abortusequi was identified in Japan, Mongolia and Croatia. OBJECTIVES: The aim of this work was to characterize S. Abortusequi isolates obtained in Argentina between 2011 and 2016 by virulence-gene profiling and pulsed-field gel electrophoresis. STUDY DESIGN: Case report. METHODS: S. Abortusequi isolates were studied by virulence-gene profiling and pulsed-field gel electrophoresis. RESULTS: Four virulence profiles and nine pulsed-field gel electrophoresis pulsotypes were identified among the 27 isolates included in the study. Different strains were found in the same outbreak and/or farm suggesting the presence of different sources of infection or mutation of isolates. MAIN LIMITATIONS: The number of related and nonrelated strains. More isolates may be necessary for a more intensive study. CONCLUSIONS: Most strains presented the same virulence profile, being positive for all the studied genes except gipA and sopE1, which are involved in intestinal virulence. Only few isolates showed different results in the same outbreak or farm. Unlike other studies, our results demonstrate a considerable diversity of S. Abortusequi pulsed-field gel electrophoresis pulsotypes, which suggests that different sources of infection may be involved within the same outbreak.


Assuntos
Genótipo , Doenças dos Cavalos/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/genética , Animais , Argentina/epidemiologia , Doenças dos Cavalos/epidemiologia , Cavalos , Salmonelose Animal/epidemiologia , Salmonella enterica/classificação , Salmonella enterica/patogenicidade , Transcriptoma , Virulência
2.
Braz J Microbiol ; 50(4): 1139-1144, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31606855

RESUMO

Salmonella enterica is an important animal and human pathogen that can cause enteritis and septicaemia in calves. Generally, antibiotics are prescribed for the treatment of salmonellosis in dairy calves. Here, we report the isolation of antibiotic resistant S. enterica serotypes from calves, including multidrug-resistant isolates. A total of 544 faecal samples from live healthy and diarrheic dairy calves from 29 commercial dairy farms and organ samples from 19 deceased calves that succumbed to salmonellosis in 12 commercial dairy farms in Uruguay were processed for selective S. enterica culture. In total, 41 isolates were serotyped, and susceptibility to 14 antibiotics, from 9 classes of compounds, was evaluated by disk-diffusion test. The minimum inhibitory concentration (MIC) was determined by microdilution. Salmonella Typhimurium was the most frequent serotype, followed by S. Dublin and S. Anatum. Whether determined by diffusion assay or microdilution, resistance to tetracycline, streptomycin and ampicillin were the most frequently pattern found. Based on MIC, 5 isolates were resistant to at least one antibiotic, 21 were resistant to 2 antibiotics, and 14 were multidrug-resistant (resistant to at least one antibiotic in 3 different categories of antibiotics). Eleven different resistance patterns were found. Multidrug resistance in S. enterica is a concern for animal and public health not only because of its zoonotic potential but also due to the possibility of transfer resistance determinants to other bacterial genera. This represents the first report of the antibiotic resistance in S. enterica in dairy farms in Uruguay.


Assuntos
Farmacorresistência Bacteriana Múltipla , Salmonelose Animal/microbiologia , Salmonella enterica/isolamento & purificação , Animais , Antibacterianos/farmacologia , Bovinos , Indústria de Laticínios , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Salmonella enterica/efeitos dos fármacos , Uruguai
3.
J Basic Microbiol ; 59(11): 1143-1153, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31577373

RESUMO

Salmonella enterica serovar Typhimurium (S. Tm) is a major intracellular pathogen that infects humans and animals, and its survival and growth in macrophages is essential for its pathogenicity. More than 50 putative regulatory proteins are encoded by the S. Tm genome, but the functions of these regulatory proteins in mediating S. Tm pathogenicity are largely unknown. In this study, we investigated the biological function of the STM0030 gene, which encodes a putative LysR-type transcriptional regulator. We found that STM0030 is upregulated 2.8-5.7-fold during S. Tm growth in macrophages. Further, mutating this gene decreased bacterial growth in macrophages and attenuated virulence in mice. RNA-sequencing to investigate the regulatory function of STM0030 in S. Tm revealed that 447 genes were differentially expressed between the mutant and the wild-type strains; 429 of these genes were downregulated, suggesting that STM0030 mainly acts as a transcriptional activator. Moreover, the expression of gluconate, maltose, and hexose-p transport genes, as well as allantoin utilization genes were downregulated in the STM0030 mutant; this might be associated with the observed decrease in intracellular replication and pathogenicity of the mutant. Our findings suggest that STM0030 is a new pathogenicity-associated regulatory protein that broadens our understanding of the virulence regulatory network of S. Tm.


Assuntos
Proteínas de Bactérias/metabolismo , Salmonella typhimurium/patogenicidade , Fatores de Transcrição/metabolismo , Fatores de Virulência/metabolismo , Animais , Proteínas de Bactérias/genética , Feminino , Regulação Bacteriana da Expressão Gênica , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Células RAW 264.7 , Salmonelose Animal/microbiologia , Salmonella typhimurium/genética , Salmonella typhimurium/crescimento & desenvolvimento , Fatores de Transcrição/genética , Virulência , Fatores de Virulência/genética
4.
Infect Immun ; 88(1)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31611277

RESUMO

To survive and replicate during infection, pathogens utilize different carbon and energy sources depending on the nutritional landscape of their host microenvironment. Salmonella enterica serovar Typhimurium is an intracellular bacterial pathogen that occupies diverse cellular niches. While it is clear that Salmonella Typhimurium requires access to glucose during systemic infection, data on the need for lipid metabolism are mixed. We report that Salmonella Typhimurium strains lacking lipid metabolism genes were defective for systemic infection of mice. Bacterial lipid import, ß-oxidation, and glyoxylate shunt genes were required for tissue colonization upon oral or intraperitoneal inoculation. In cultured macrophages, lipid import and ß-oxidation genes were required for bacterial replication and/or survival only when the cell culture medium was supplemented with nonessential amino acids. Removal of glucose from tissue culture medium further enhanced these phenotypes and, in addition, conferred a requirement for glyoxylate shunt genes. We also observed that Salmonella Typhimurium needs lipid metabolism genes in proinflammatory but not anti-inflammatory macrophages. These results suggest that during systemic infection, the Salmonella Typhimurium that relies upon host lipids to replicate is within proinflammatory macrophages that have access to amino acids but not glucose. An improved understanding of the host microenvironments in which pathogens have specific metabolic requirements may facilitate the development of targeted approaches to treatment.


Assuntos
Metabolismo dos Lipídeos , Macrófagos/microbiologia , Redes e Vias Metabólicas/genética , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/metabolismo , Aminoácidos/metabolismo , Animais , Glucose/metabolismo , Camundongos , Viabilidade Microbiana , Salmonelose Animal/microbiologia , Salmonelose Animal/patologia , Salmonella typhimurium/genética
5.
Infect Immun ; 88(1)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31611279

RESUMO

Salmonella enterica serovar Typhimurium (S Typhimurium) relies upon the inner membrane protein PbgA to enhance outer membrane (OM) integrity and promote virulence in mice. The PbgA transmembrane domain (residues 1 to 190) is essential for viability, while the periplasmic domain (residues 191 to 586) is dispensable. Residues within the basic region (residues 191 to 245) bind acidic phosphates on polar phospholipids, like for cardiolipins, and are necessary for salmonella OM integrity. S Typhimurium bacteria increase their OM cardiolipin concentrations during activation of the PhoPQ regulators. The mechanism involves PbgA's periplasmic globular region (residues 245 to 586), but the biological role of increasing cardiolipins on the surface is not understood. Nonsynonymous polymorphisms in three essential lipopolysaccharide (LPS) synthesis regulators, lapB (also known as yciM), ftsH, and lpxC, variably suppressed the defects in OM integrity, rifampin resistance, survival in macrophages, and systemic colonization of mice in the pbgAΔ191-586 mutant (in which the PbgA periplasmic domain from residues 191 to 586 is deleted). Compared to the OMs of the wild-type salmonellae, the OMs of the pbgA mutants had increased levels of lipid A-core molecules, cardiolipins, and phosphatidylethanolamines and decreased levels of specific phospholipids with cyclopropanated fatty acids. Complementation and substitution mutations in LapB and LpxC generally restored the phospholipid and LPS assembly defects for the pbgA mutants. During bacteremia, mice infected with the pbgA mutants survived and cleared the bacteria, while animals infected with wild-type salmonellae succumbed within 1 week. Remarkably, wild-type mice survived asymptomatically with pbgA-lpxC salmonellae in their livers and spleens for months, but Toll-like receptor 4-deficient animals succumbed to these infections within roughly 1 week. In summary, S Typhimurium uses PbgA to influence LPS assembly during stress in order to survive, adapt, and proliferate within the host environment.


Assuntos
Bacteriemia/microbiologia , Lipopolissacarídeos/metabolismo , Salmonella typhimurium/metabolismo , Salmonella typhimurium/patogenicidade , Animais , Teste de Complementação Genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Salmonelose Animal/microbiologia , Deleção de Sequência , Análise de Sobrevida , Virulência
6.
PLoS Pathog ; 15(9): e1007948, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31560731

RESUMO

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These findings were consistent with the essentiality analyses of other S. Typhimurium ST19 and S. Typhi strains. The global mutagenesis approach also identified 60 sRNAs and 413 intergenic regions required for growth in at least one in vitro growth condition. By infecting murine macrophages with the transposon library, we identified 68 genes that were required for intra-macrophage replication but did not impact fitness in vitro. None of these genes were unique to S. Typhimurium D23580, consistent with a high conservation of gene function between S. Typhimurium ST313 and ST19 and suggesting that novel virulence factors are not involved in the interaction of strain D23580 with murine macrophages. We discovered that transposon insertions rarely occurred in many pBT1 plasmid-encoded genes (36), compared with genes carried by the pSLT-BT virulence plasmid and other bacterial plasmids. The key essential protein encoded by pBT1 is a cysteinyl-tRNA synthetase, and our enzymological analysis revealed that the plasmid-encoded CysRSpBT1 had a lower ability to charge tRNA than the chromosomally-encoded CysRSchr enzyme. The presence of aminoacyl-tRNA synthetases in plasmids from a range of Gram-negative and Gram-positive bacteria suggests that plasmid-encoded essential genes are more common than had been appreciated.


Assuntos
Salmonella typhimurium/fisiologia , Salmonella typhimurium/patogenicidade , Animais , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Genes Bacterianos , Aptidão Genética , Macrófagos/microbiologia , Camundongos , Plasmídeos/genética , Células RAW 264.7 , Salmonelose Animal/microbiologia , Salmonella typhimurium/genética , Virulência/genética , Virulência/fisiologia
7.
PLoS Pathog ; 15(9): e1008029, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31545853

RESUMO

Although Escherichia coli Nissle 1917 (EcN) has been used therapeutically for over a century, the determinants of its probiotic properties remain elusive. EcN produces two siderophore-microcins (Mcc) responsible for an antagonistic activity against other Enterobacteriaceae. EcN also synthesizes the genotoxin colibactin encoded by the pks island. Colibactin is a virulence factor and a putative pro-carcinogenic compound. Therefore, we aimed to decouple the antagonistic activity of EcN from its genotoxic activity. We demonstrated that the pks-encoded ClbP, the peptidase that activates colibactin, is required for the antagonistic activity of EcN. The analysis of a series of ClbP mutants revealed that this activity is linked to the transmembrane helices of ClbP and not the periplasmic peptidase domain, indicating the transmembrane domain is involved in some aspect of Mcc biosynthesis or secretion. A single amino acid substitution in ClbP inactivates the genotoxic activity but maintains the antagonistic activity. In an in vivo salmonellosis model, this point mutant reduced the clinical signs and the fecal shedding of Salmonella similarly to the wild type strain, whereas the clbP deletion mutant could neither protect nor outcompete the pathogen. The ClbP-dependent antibacterial effect was also observed in vitro with other E. coli strains that carry both a truncated form of the Mcc gene cluster and the pks island. In such strains, siderophore-Mcc synthesis also required the glucosyltransferase IroB involved in salmochelin production. This interplay between colibactin, salmochelin, and siderophore-Mcc biosynthetic pathways suggests that these genomic islands were co-selected and played a role in the evolution of E. coli from phylogroup B2. This co-evolution observed in EcN illustrates the fine margin between pathogenicity and probiotic activity, and the need to address both the effectiveness and safety of probiotics. Decoupling the antagonistic from the genotoxic activity by specifically inactivating ClbP peptidase domain opens the way to the safe use of EcN.


Assuntos
Escherichia coli/fisiologia , Mutagênicos/toxicidade , Probióticos/uso terapêutico , Animais , Antibiose/genética , Antibiose/fisiologia , Bacteriocinas/genética , Bacteriocinas/metabolismo , Bacteriocinas/toxicidade , Vias Biossintéticas/genética , Enterobactina/análogos & derivados , Enterobactina/genética , Enterobactina/fisiologia , Enterobactina/toxicidade , Escherichia coli/genética , Escherichia coli/patogenicidade , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/fisiologia , Feminino , Genes Bacterianos , Ilhas Genômicas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Família Multigênica , Mutação , Peptídeo Hidrolases/química , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/fisiologia , Peptídeos/genética , Peptídeos/fisiologia , Peptídeos/toxicidade , Policetídeos/toxicidade , Probióticos/toxicidade , Domínios Proteicos , Salmonelose Animal/microbiologia , Salmonelose Animal/terapia , Salmonella typhimurium , Sideróforos/genética , Sideróforos/fisiologia , Sideróforos/toxicidade , Fatores de Virulência/genética , Fatores de Virulência/fisiologia , Fatores de Virulência/toxicidade
8.
Vet Res ; 50(1): 71, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551081

RESUMO

Eggs and raw or undercooked egg-containing food items are frequently identified as the bacterial source during epidemiolocal investigation of Salmonella outbreaks. Multi-locus variable number of tandem repeats analysis (MLVA) is a widely used Salmonella typing method enabling the study of diversity within populations of the same serotype. In vivo passage, however, has been linked with changes in MLVA type and more broadly the Salmonella genome. We sought to investigate whether in vivo passage through layer hens had an effect on MLVA type as well as the bacterial genome and whether any mutations affected bacterial virulence. Layer hens were infected with either Salmonella Typhimurium DT9 (03-24-11-11-523) as part of a single infection or were co-infected with an equal amount of Salmonella Mbandaka. Salmonella shedding in both single and co-infected birds was variable over the course of the 16-week experiment. Salmonella Typhimurium and Salmonella Mbandaka were identified in feces of co-infected birds. Salmonella colonies isolated from fecal samples were subtyped using MLVA. A single change in SSTR-6 was observed in Salmonella Typhimurium strains isolated from co-infected birds. Isolates of Salmonella Typhimurium of both the parent (03-24-11-11-523) and modified (03-24-12-11-523) MLVA type were sequenced and compared with the genome of the parent strain. Sequence analysis revealed that in vivo passaging resulted in minor mutation events. Passaged isolates exhibited significantly higher invasiveness in cultured human intestinal epithelial cells than the parent strain. The microevolution observed in this study suggests that changes in MLVA may arise more commonly and may have clinical significance.


Assuntos
Galinhas , Genoma Bacteriano/genética , Mutação/fisiologia , Doenças das Aves Domésticas/fisiopatologia , Salmonelose Animal/fisiopatologia , Salmonella typhimurium/fisiologia , Animais , Células CACO-2 , Coinfecção/microbiologia , Coinfecção/fisiopatologia , Coinfecção/veterinária , Fezes/microbiologia , Feminino , Humanos , Repetições Minissatélites , Tipagem de Sequências Multilocus/veterinária , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/fisiologia , Salmonella typhimurium/genética , Inoculações Seriadas , Virulência
9.
Int J Food Microbiol ; 310: 108310, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31476581

RESUMO

Pigs infected with Salmonella are an important source of contamination at slaughterhouses. We characterized the distribution, virulence genotypes and antimicrobial-resistance phenotypes for Salmonella isolates that were collected from different stages of a pork production chain. Each of ten pig lots were sampled for feed (n = 10), water (n = 10), barn floor (n = 10), lairage floor (n = 10), mesenteric lymph nodes (n = 100), tonsils (n = 100), processing environment (n = 120), pork cuts (n = 40) and carcasses after bleeding (n = 100), after singeing (n = 100), after evisceration (n = 100), and after final rinsing (n = 100). Salmonella was isolated according to ISO 6579, and after confirmation the isolates were subjected to serogrouping, macro-restriction digests and pulsed-field gel electrophoresis (PFGE), detection of virulence-related genes and antimicrobial-resistance phenotyping. Salmonella was recovered from barn floors from 3 pig farms (3/10), lairage floors (7/10), carcasses after bleeding (2/100) and final washing (1/100), palatine tonsils (45/100), mesenteric lymph nodes (43/100), utensils (3/120) and cuts (4/40). The most prevalent serogroup was O: 4 (82%) followed by O:3 (7.7%); O:9 (5.1%); O:8 (2.6%) and O:7 (2.6%). Recovered strains (n = 109) were classified into 24 different pulsotypes (XbaI restriction digest), which were arranged into five different clusters. Fourteen different virulence genotypes were observed based on 15 loci, and all isolates were positive for invA, sitC, pagC and tolC. There was a high prevalence of antimicrobial resistance against streptomycin (90.5%), tetracycline (88.1%), ampicillin (81.0%), chloramphenicol (71.4%), and ciprofloxacin (50.0%). No strain was resistant to ertapenem, meropenem or kanamycin. A majority (80.9%) of isolates were considered multidrug resistant (resistant to ≥3 antibiotic classes). This study provides valuable insight about the epidemiology of Salmonella in swine production, and despite the low presence of this pathogen in carcasses and meat cuts, the majority of isolates was multidrug resistant.


Assuntos
Resistência Microbiana a Medicamentos/genética , Variação Genética , Salmonella , Virulência/genética , Matadouros , Animais , Antibacterianos/farmacologia , Brasil , Eletroforese em Gel de Campo Pulsado , Genótipo , Carne/microbiologia , Tonsila Palatina/microbiologia , Prevalência , Salmonella/classificação , Salmonella/efeitos dos fármacos , Salmonella/genética , Salmonella/isolamento & purificação , Salmonelose Animal/microbiologia , Sorogrupo , Suínos , Doenças dos Suínos/microbiologia
10.
Acta Trop ; 200: 105123, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401191

RESUMO

Salmonella Zega isolated from natural outbreaks that were characterized by high mortality in poultry farms in three Southwestern States of Nigeria was used to inoculate two week-old chicks through different routes in order to determine and compare the clinical signs, pathological and immunohistochemical changes in each route of infection. The birds were divided into 4 groups of 25 each as groups A (orally inoculated), B (intraperitoneally inoculated), C (inoculated per cloaca) and D (uninoculated control). All the birds were inoculated with 0.2 ml of 1 × 108 cfu of the bacteria. Clinical signs were observed and recorded according to the route of infection, and with the days post-infection from day 0 till day 10 post-infection. Two birds from each group were sacrificed every 24 h and examined for gross lesions, which were described and scored according to the route of infection and days post-infection. Samples of visceral organs were collected for bacteriology, histopathology and immunohistochemistry. Clinical signs in chicks infected orally and intraperitoneally were weakness, anoraexia lethargy, somnolescence, yellowish diarrhoea observed from 4 days till day 10 post infections. Mild sign of weakness was observed in chickes infected per cloaca, from day 3 to 7. The gross lesions were congestion, oedema and enlargement and necrosis in visceral organs from day 4 to 10 post infection in orally and intraperitoneally infected chicks, but mild vascular changes were observed in chicks infected per cloaca, except in the caecum were lesions of necrosis and infiltration of inflammatory cells were moderate to severe. Microscopic lesions were necrosis of host cells and infiltration by lymphocytes, heterophils and macrophages in multiple organs observed from day 4 to 10 post infection in orally and intraperitoneally infected chicks. Immunoreactions were observed in all the visceral organs examined. Clinical signs, pathological and immunohistochemical findings were mild in chicks infected per cloaca, except caecal lesions. Salmonella Zega isolated from an outbreak in poultry farms in Abeokuta, Nigeria was highly pathogenic in chicken and produced similar findings in oral and intraperitoneal infections; while per cloacal infection showed a localized infection of the caecum.


Assuntos
Ceco/microbiologia , Galinhas/microbiologia , Progressão da Doença , Salmonelose Animal/microbiologia , Salmonelose Animal/fisiopatologia , Salmonella enterica/isolamento & purificação , Animais , Nigéria/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia
11.
BMC Res Notes ; 12(1): 472, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370868

RESUMO

OBJECTIVES: Salmonella is the most important causes of foodborne illness especially from poultry and poultry products. So the aim of this study was to carryout phenotypic characterization, antimicrobials susceptibility pattern and risk factors of Salmonella isolates from farms and markets eggs, cloacae swabs of chickens and stool of egg collectors. A cross-sectional study was conducted from January 2018 to September 2018. Samples were, processed; Salmonella was isolated, phenotypically identified by OmniLog and antimicrobials susceptibility were carried out. RESULT: Over all; 11 (2.65%) of Salmonella enterica were phenotypically characterized out of 415 samples from farms egg content (n = 83), farms eggshell (n = 83), cloacae (n = 83), market eggshell (n = 83) and market egg contents (n = 83) with 2.4%, 0%, 2.4%, 4.8% and 3.6% prevalence, respectively. Out of isolates, 8 (72.72%) displayed multidrug resistance. All isolates showed susceptibility to Gentamicin, Kanamycin and Streptomycin. Lack of separating cracked eggs, washing hand, eggs stay longer unsold, and mixing excreta with feed were associated risk factors for Salmonella presence (P-value < 0.05). The presence of drug resistant Salmonella enterica within egg/and chicken can pose serious health problem. Good hygienic practices are important to reduce risk factors of Salmonella contamination.


Assuntos
Criação de Animais Domésticos/ética , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella enterica/isolamento & purificação , Animais , Antibacterianos/farmacologia , Galinhas , Estudos Transversais , Ovos/microbiologia , Etiópia/epidemiologia , Fazendeiros , Fazendas , Fezes/microbiologia , Gentamicinas/farmacologia , Humanos , Higiene/educação , Canamicina/farmacologia , Testes de Sensibilidade Microbiana , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/transmissão , Prevalência , Fatores de Risco , Salmonelose Animal/microbiologia , Salmonelose Animal/transmissão , Salmonella enterica/efeitos dos fármacos , Estreptomicina/farmacologia
12.
Res Vet Sci ; 126: 59-67, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442714

RESUMO

Antimicrobial resistance is a major public health concern, and food systems are a crucial point in the epidemiology of these resistances. Among antimicrobials, critically important ones are therapeutic drugs that should be primarily safeguarded to allow successful outcomes against important bacterial infections in humans. The most important source of antimicrobial resistance has been recognized in the inappropriate use of antimicrobials in human and animal medicine, with farming being a critical stage. Products of animal origin are the link between animal and humans and can contribute to the spread of antimicrobial resistance, in particular through bacteria such as Enterobacteriaceae, commonly present in both animals' gut and food. Salmonella is an important member of this bacterial family due to its pathogenicity, its noteworthy prevalence and the frequent detection of resistance genes in different isolates. In the present systematic review, the distribution of antimicrobial resistance determinants among Salmonella enterica serovars in pigs, cattle and poultry production was investigated in the European context. A comprehensive literature search was carried out in three different databases, and 7955 papers were identified as relevant. After the different steps of the review process, 31 papers were considered eligible for data extraction to gain insight about sources and reservoirs for such genes. Results suggest that despite the increasing attention directed toward antimicrobial resistance in animal production, a wide plethora of genes still exist and further actions should be undertaken to face this challenge.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Microbiologia de Alimentos , Salmonelose Animal/microbiologia , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Animais , Humanos , Salmonella enterica/efeitos dos fármacos
13.
Infect Immun ; 87(11)2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31427450

RESUMO

Salmonella infection can cause gastroenteritis in healthy individuals or a serious, systemic infection in immunocompromised patients and has a global impact. CD4 Th1 cells represent the main lymphocyte population that participates in bacterial clearance during both primary and secondary infections in mice of the H-2b haplotype. Previous studies have used congenic mice to examine the function of major histocompatibility complex (MHC) molecules in elimination of this pathogen from the host. In this study, we further characterized the ability of H-2b, H-2k, and H-2u molecules to influence adaptive immunity to Salmonella in MHC congenic mice. By depleting different cell populations during infection, we unexpectedly found that CD8 T cells, in addition to CD4 T cells, play a major role in accelerated clearance of bacteria from H-2k congenic hosts. Our data suggest that CD8 T cells accelerate clearance in some MHC congenic mouse strains and could therefore represent an unexpected contributor to the protective efficacy of Salmonella vaccines outside the typical studies in C57BL/6 mice.


Assuntos
Linfócitos T CD8-Positivos/fisiologia , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia muridarum , Haplótipos , Interferon gama , Complexo Principal de Histocompatibilidade/genética , Camundongos
14.
J Appl Microbiol ; 127(6): 1869-1875, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31461201

RESUMO

AIMS: Given the significance of Salmonella enterica in both human and animal health, and a recent global dissemination of Salmonella 4,[5],12:i:-, changes in the prevalent serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs were investigated in Japan. METHODS AND RESULTS: The serovars and antimicrobial susceptibilities of 1605 Salmonella enterica isolated from cattle (n = 894) and swine (n = 711) between 2002 and 2016 were examined. The most common serovar among all samples was Salmonella Typhimurium. However, its monophasic variant with antigenic structure S. 4,[5],12:i:-, which was first detected in cattle in 2006 and swine in 2010, has been rapidly increasing in incidence and resistance. Resistance rates to cefotaxime and ciprofloxacin were generally low (<10% in the cattle isolates and <5% in the swine isolates); however, isolates resistant to more than five antimicrobials, which often include these antimicrobials, were recently detected in Salmonella Dublin, S. 4,[5],12:i:-, S. Typhimurium, Salmonella Newport, Salmonella Choleraesuis and Salmonella 6,7:c:-. Among them, two S. 4,[5],12:i:- isolates possessed extended-spectrum ß-lactamase-encoding genes; blaSHV-12 or blaCTX-M-55 , respectively, while all the five S. Typhimurium isolates possessed AmpC-type ß-lactamase gene of blaCMY-2 . CONCLUSIONS: S. 4,[5],12:i:- has been rapidly increasing and exhibiting a remarkable change in antimicrobial resistance in Japan. Considering certain serovars are characterized by multidrug resistance including medically important antimicrobials, continuous monitoring and appropriate measures are required to protect public health and veterinary husbandry. SIGNIFICANCE AND IMPACT OF THE STUDY: This study presents a trend in the serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs in Japan, and showed that there were certain types of Salmonella serovars depending on the animal origin which needs more attention.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , Bovinos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Japão/epidemiologia , Testes de Sensibilidade Microbiana , Salmonelose Animal/epidemiologia , Salmonella enterica/isolamento & purificação , Sorogrupo , Suínos
15.
Vet Res ; 50(1): 58, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362780

RESUMO

Human cases of salmonellosis are frequently liked with the consumption of contaminated table eggs. Recently, there has been an increase in consumer demand for cage-free eggs precipitating the need for a greater understanding of Salmonella dynamics in free-range production systems. A longitudinal study was conducted to determine the points in production where birds are most likely to be exposed to Salmonella and where the risk of egg contamination is highest. In this study, two free-range flocks were sampled from hatch to the end of production. At hatch, all chicks were Salmonella negative and remained negative during rearing. During production, the proportion of positive samples was low on both farms. Salmonella positive samples were detected intermittently for Flock A. Dust, nest box, and egg belt swabs had the highest proportion of positive samples and highest overall loads of Salmonella. The egg grading floor was swabbed at different points following the processing of eggs from Flock A. Only the suction cups that handle eggs prior to egg washing tested positive for Salmonella. Swabs collected from machinery handling eggs after washing were Salmonella negative. During production, positive samples from Flock B were observed at only single time point. Dust has been implicated as a source of Salmonella that can lead to flock to flock contamination. Bulk dust samples were collected and tested for Salmonella. The proportion of positive dust samples was low and is likely due to physical parameters which are not likely to support the survival of Salmonella in the environment.


Assuntos
Criação de Animais Domésticos , Derrame de Bactérias , Galinhas , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella/fisiologia , Criação de Animais Domésticos/métodos , Animais , Austrália/epidemiologia , Estudos Longitudinais , Óvulo/microbiologia , Doenças das Aves Domésticas/microbiologia , Prevalência , Fatores de Risco , Salmonelose Animal/microbiologia
16.
Poult Sci ; 98(11): 5961-5970, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31392329

RESUMO

Village chicken or Ayam Kampung, common to Southeast Asian countries, has always been regarded as superior in comparison to commercial broiler chicken in terms of wholesomeness and health benefits. The current study investigates the prevalence and risk factors of Salmonella among village chicken flocks from the central and southern states of Peninsular Malaysia. A total of 35 village flocks were sampled from Selangor (n = 19), Melaka (n = 10), Johor (n = 4), and Negeri Sembilan (n = 2). In total, 1,042 samples were collected; these included cloacal swabs (n = 675), eggs (n = 62), pooled drinking water (n = 175), pooled feeds (n = 70), and pooled flies (n = 60). Isolation of Salmonella from cloacal swabs, poultry drinking water, and feeds was carried out according to the protocols and recommendations of the World Organization for Animal Health (OIE) terrestrial manual. The prevalence of Salmonella at an individual bird-level was 2.5% (17/675, 95% CI: 1.6 to 4.0). All eggs screened were negative; in the case of environmental samples, however, Salmonella was detected in 5.14% (9/175), 7.14% (5/70), and 5.0% (3/60) for water, feed, and flies, respectively. A total of 34 isolates and 8 Salmonella serotypes were identified. Weltevreden (20.6%) was the most common, followed by Typhimurium and Agona (17.6%), Albany and Enteritidis (8.8%), Molade (5.9%), Corvallis and Schleissheim (2.9%), and others grouped as Salmonella spp. (11.8%). Multivariable logistic regression models revealed that Salmonella positivity among flocks could be strongly predicted by storage of feeds (uncovered feeds; OR = 10.38; 95% CI: 1.25 to 86.39; p = 0.030) and uncovered water tanks (uncovered tank; OR = 6.43; 95% CI: 1.02 to 40.60; p = 0.048). The presence of Salmonella in village chickens in the study area was lower than that of commercial chickens in Malaysia.


Assuntos
Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella/isolamento & purificação , Animais , Galinhas , Fazendas , Malásia/epidemiologia , Doenças das Aves Domésticas/microbiologia , Prevalência , Fatores de Risco , Salmonelose Animal/microbiologia
17.
Rev Inst Med Trop Sao Paulo ; 61: e36, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31340248

RESUMO

During the last years, Brazilian government control programs have detected an increase of Salmonella Heidelberg in poultry slaughterhouses a condition that poses a threat to human health However, the reasons remain unclear. Differences in genetic virulence profiles may be a possible justification. In addition, effective control of Salmonella is related to an efficient epidemiological surveillance system through genotyping techniques. In this context, the aim of this study was the detection of 24 virulence-associated genes in 126 S. Heidelberg isolates. We classified the isolates into 56 different genetic profiles. None of the isolates presented all the virulence genes. The prevalence of these genes was high in all tested samples as the lowest number of genes detected in one isolate was 10/24. The lpfA and csgA (fimbriae), invA and sivH (TTSS), and msgA and tolC (intracellular survival) genes were present in 100% of the isolates analyzed. Genes encoding effector proteins were detected in the majority of SH isolates. No single isolate had the sefA gene. The pefA gene was found in only four isolates. We have also performed a screening of genes associated with iron metabolism: 88.9% of isolates had the iroN geneand 79.4% the sitC gene . Although all the isolates belong to the same serotype, several genotypic profiles were observed. These findings suggest that there is a diversity of S. Heidelberg isolates in poultry products. The fact that a single predominant profile was not found in this study indicates the presence of variable sources of contamination caused by SH. The detection of genetic profiles of Salmonella strains can be used to determine the virulence patterns of SH isolates.


Assuntos
Doenças das Aves Domésticas/microbiologia , Produtos Avícolas/microbiologia , Salmonelose Animal/microbiologia , Salmonella/genética , Salmonella/patogenicidade , Fatores de Virulência/genética , Virulência/genética , Animais , Microbiologia de Alimentos , Genótipo , Reação em Cadeia da Polimerase
18.
PLoS Negl Trop Dis ; 13(7): e0007540, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31348776

RESUMO

Over recent decades, Salmonella infection research has predominantly relied on murine infection models. However, in many cases the infection phenotypes of Salmonella pathovars in mice do not recapitulate human disease. For example, Salmonella Typhimurium ST313 is associated with enhanced invasive infection of immunocompromised people in Africa, but infection of mice and other animal models with ST313 have not consistently reproduced this invasive phenotype. The introduction of alternative infection models could help to improve the quality and reproducibility of pathogenesis research by facilitating larger-scale experiments. To investigate the virulence of S. Typhimurium ST313 in comparison with ST19, a combination of avian and insect disease models were used. We performed experimental infections in five lines of inbred and one line of outbred chickens, as well as in the alternative chick embryo and Galleria mellonella wax moth larvae models. This extensive set of experiments identified broadly similar patterns of disease caused by the African and global pathovariants of Salmonella Typhimurium in the chicken, the chicken embryo and insect models. A comprehensive analysis of all the chicken infection experiments revealed that the African ST313 isolate D23580 had a subtle phenotype of reduced levels of organ colonisation in inbred chickens, relative to ST19 strain 4/74. ST313 isolate D23580 also caused reduced mortality in chicken embryos and insect larvae, when compared with ST19 4/74. We conclude that these three infection models do not reproduce the characteristics of the systemic disease caused by S. Typhimurium ST313 in humans.


Assuntos
Galinhas/microbiologia , Insetos/microbiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/patogenicidade , África , Animais , Embrião de Galinha , Modelos Animais de Doenças , Larva/microbiologia , Mariposas/microbiologia , Reprodutibilidade dos Testes , Salmonelose Animal/mortalidade , Salmonella typhimurium/genética , Virulência
19.
Comp Immunol Microbiol Infect Dis ; 65: 154-159, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31300107

RESUMO

Turtoises are a great puzzle when it comes to their bacterial flora, the composition and structure of which are still unknown in details. Its component which has been best described so far is Salmonella spp., presumably due to the threat of reptile-associated salmonellosis in humans. This investigation tried to assess and characterize intestinal bacterial flora of imported tortoises found dead during quarantine. Most of the animals carried various serovars of Salmonella showing no antimicrobial resistance. Presence of multiresistant Escherichia coli was possibly a result of industrial breeding and high usage of antimicrobials. Thirteen bacterial species or genera like Citrobacter spp., Morganella spp., Pseudomonas spp. were identified. Their commensal character is assumed, although pathogenic potential might be verified. The results indicate global tortoise trade as a source of common and exotic bacteria or antimicrobial resistance mechanisms in new geographical areas. These dangers indicate the need for a systematic survey of exotic pets and establishment of legal requirements for reptile health conditions on breeding, trade premises and in households with such pets.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/veterinária , Microbiota , Animais de Estimação/microbiologia , Tartarugas/microbiologia , Animais , Bactérias/efeitos dos fármacos , Bactérias/patogenicidade , Infecções Bacterianas/mortalidade , Doenças Transmissíveis Importadas/microbiologia , Doenças Transmissíveis Importadas/transmissão , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Feminino , Microbioma Gastrointestinal , Testes de Sensibilidade Microbiana , Saúde Pública , Quarentena/veterinária , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Salmonelose Animal/microbiologia , Salmonelose Animal/mortalidade , Zoonoses/microbiologia , Zoonoses/transmissão
20.
Vet Microbiol ; 235: 63-70, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282380

RESUMO

Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid (FT) and substantial economic loss in Korea due to egg drop syndrome and mortality. Despite the extensive use of vaccines, FT still occurs in the field. Therefore, the emergence of more pathogenic SG or the recovered pathogenicity of a vaccine strain has been suspected. SpvB, an ADP-ribosyl transferase, is a major pathogenesis determinant, and the length of the polyproline linker (PPL) of SpvB affects pathogenic potency. SG strains accumulate pseudogenes in their genomes during host adaptation, and pseudogene profiling may provide evolutionary information. In this study, we found that the PPL length of Korean SG isolates varied from 11 to 21 prolines and was longer than that of a live vaccine strain, SG 9R (9 prolines). According to growth competition in chickens, the growth of an SG isolate with a PPL length of 17 prolines exceeded that of an SG isolate with a PPL length of 15 prolines. We investigated the pseudogenes of the field isolates, SG 9R and reference strains in GenBank by resequencing and comparative genomics. The pseudogene profiles of the field isolates were notably different from those of the foreign SG strains, and they were subdivided into 7 pseudogene subgroups. Collectively, the field isolates had gradually evolved by changing PPL length and acquiring additional pseudogenes. Thus, the characterization of PPL length and pseudogene profiling may be useful to understand the molecular evolution of SG and the epidemiology of FT.


Assuntos
Galinhas/microbiologia , Evolução Molecular , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/genética , ADP Ribose Transferases/genética , Animais , Surtos de Doenças , Ligantes , Peptídeos/genética , Pseudogenes , República da Coreia , Salmonella enterica/isolamento & purificação , Sorogrupo
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