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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.
Int J Food Microbiol ; 310: 108359, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31655448

RESUMO

A dearth of knowledge exists on the pathogen-commodity association of Salmonella enterica on cucumber, despite cucumbers being implicated in multiple salmonellosis outbreaks in recent years in the U.S. Data are lacking on cultivar susceptibility to Salmonella colonization in relation to heterogeneity in fruit surface morphology. Further, fruit waxing is a common practice in wholesale cucumber to preserve the water content of fruit and prolong shelf-life, but its impact on epiphytic microbiota is not well studied. This study investigated the survival of Salmonella Newport and S. Javiana on the surface of six cucumber cultivars of varying surface morphology and the effect of fruit waxing on the persistence of S. Newport. S. Newport and S. Javiana were spot inoculated onto fruit of cultivars 'Marketmore 97', 'Patio Snacker' and 'Corinto' (varieties with trichomes or spines), and 'Bella', 'Pepinex' and 'Summer Dance' (glabrous or smooth varieties). Cucumbers were held at room temperature for 24 h before inoculated sections of exocarp were excised for enteropathogen enumeration. S. Javiana persisted at higher populations than S. Newport (1.0 and 1.5 log CFU g-1 exocarp decline, respectively) after 24 h (P < 0.05). Fruit waxing lessened S. Newport population decline after 24 h on all cultivars tested (P < 0.01). While there was a ~2 log CFU g-1 exocarp decline in populations on unwaxed cucumbers, the reduction on waxed cucumbers was ~1 log CFU g-1 exocarp. A cultivar effect was also observed; 'Summer Dance' supported consistently higher and 'Corinto' and 'Marketmore 97' (though for S. Javiana only) consistently lower Salmonella levels. Cultivars with trichomes were associated with lower populations than glabrous cultivars (P < 0.05). Our data showed that Salmonella persistence on fruit differed for the two serotypes tested and that cultivar differences play a role in determining cucumber surface favourability for pathogen colonization. Additionally, fruit waxing may elevate the risk of Salmonella persistence on cucumber.


Assuntos
Cucumis sativus/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Conservantes de Alimentos/normas , Salmonella enterica/classificação , Salmonella enterica/fisiologia , Sorogrupo
3.
Int J Food Microbiol ; 307: 108275, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31408739

RESUMO

Salmonella enterica subsp. enterica serovar Infantis (S. Infantis) isolates were found to have a multi-drug resistance profile (kanamycin, streptomycin, nalidixic acid, tetracycline, sulfonamide, and sometimes to ampicillin) and high prevalence (91%) in Turkish poultry in our previous studies. To investigate the mechanism behind multi-drug antimicrobial resistance (AMR) and high prevalence in Turkish poultry, 23 of the isolates were sequenced for comparative genomic analyses including: SNP-based comparison to S. Infantis from other countries, comparison of antimicrobial resistance genes (AMGs) with AMR phenotypes, and plasmid identification and annotation. Whole-genome SNP-based phylogenetic analysis found that all 23 Turkish S. Infantis isolates formed a distinct, well-supported clade, separate from 243 comparison S. Infantis genomes in GenomeTrakr identified as from the US and EU; the isolates most closely related to the cluster of these Turkish isolates were from Israel and Egypt. AMGs identified by bioinformatic analysis, without differentiating chromosomal or plasmid located genes, implied AMR phenotypes with 94% similarity overall to wet lab data, which was performed by phenotypic and conventional PCR methods. Most of the S. Infantis (21/23) isolates had identifiable plasmids, with 76% (16/21) larger than 100 kb and 48% (10/21) larger than 200 kb. A plasmid larger than 200 kb, with the incompatibility type of IncX1, similar to United States S. Infantis plasmid N55391 (99% query coverage and 99% identity overall), which itself is similar to Italian and Hungarian S. Infantis plasmids. Turkish S. Infantis plasmids had different beta-lactam resistance genes (blaTEM-70, blaTEM-148 and blaTEM-198) than the gene blaCTX-M-65 found in S. Infantis plasmids from other countries. This is the first observation of these three genes in S. Infantis isolates. The plasmids larger than 200 kb had two distinct regions of interest: Site 1 and Site 2. Site 1 (around 130 kb) had virulence- and bacteriocin- associated genes such as bacteriocin secretion system and type II toxin-antitoxin system genes (vagC, ccdA, ccdB, mchE, cvaB) and an aminoglycoside resistance gene (str). Site 2 (around 75-110 kb) had the antimicrobial resistance genes (aadA, sulI, tetA, tetR) and mercury (mer) resistance gene on tranposons Tn552 and Tn501. Presence of these AMR and virulence genes suggests they may have a role in the emergence of S. Infantis in poultry and support treating this serotype as a an important human health hazard.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Plasmídeos/genética , Salmonella enterica/genética , Salmonella enterica/patogenicidade , Animais , Genoma Bacteriano/genética , Filogenia , Aves Domésticas , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Turquia , Virulência/genética
4.
PLoS Negl Trop Dis ; 13(6): e0007169, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31163033

RESUMO

BACKGROUND: Reptile-associated Salmonella bacteria are a major, but often neglected cause of both gastrointestinal and bloodstream infection in humans globally. The diversity of Salmonella enterica has not yet been determined in venomous snakes, however other ectothermic animals have been reported to carry a broad range of Salmonella bacteria. We investigated the prevalence and diversity of Salmonella in a collection of venomous snakes and non-venomous reptiles. METHODOLOGY/PRINCIPLE FINDINGS: We used a combination of selective enrichment techniques to establish a unique dataset of reptilian isolates to study Salmonella enterica species-level evolution and ecology and used whole-genome sequencing to investigate the relatedness of phylogenetic groups. We observed that 91% of venomous snakes carried Salmonella, and found that a diverse range of serovars (n = 58) were carried by reptiles. The Salmonella serovars belonged to four of the six Salmonella enterica subspecies: diarizonae, enterica, houtanae and salamae. Subspecies enterica isolates were distributed among two distinct phylogenetic clusters, previously described as clade A (52%) and clade B (48%). We identified metabolic differences between S. diarizonae, S. enterica clade A and clade B involving growth on lactose, tartaric acid, dulcitol, myo-inositol and allantoin. SIGNIFICANCE: We present the first whole genome-based comparative study of the Salmonella bacteria that colonise venomous and non-venomous reptiles and shed new light on Salmonella evolution. Venomous snakes examined in this study carried a broad range of Salmonella, including serovars which have been associated with disease in humans such as S. Enteritidis. The findings raise the possibility that venomous snakes could be a reservoir for Salmonella serovars associated with human salmonellosis.


Assuntos
Variação Genética , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Serpentes/microbiologia , Animais , Prevalência , Sorogrupo , Sequenciamento Completo do Genoma
5.
Microb Genom ; 5(7)2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31166889

RESUMO

Salmonellaenterica serovar Kentucky is an emergent human pathogen. Human infection with ciprofloxacin-resistant S. enterica Kentucky ST198 has been reported in Europe and North America as a consequence of travel to Asia/the Middle East. This is, to the best of our knowledge, the first study reporting the identification of this epidemic clone in India and South Asia.


Assuntos
Antibacterianos/farmacologia , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificação , Animais , Antibacterianos/uso terapêutico , Ciprofloxacino/uso terapêutico , DNA Bacteriano/genética , Humanos , Índia/epidemiologia , Filogenia , Salmonelose Animal/tratamento farmacológico , Salmonella enterica/classificação , Salmonella enterica/genética , Sorogrupo , Sequenciamento Completo do Genoma
6.
BMC Infect Dis ; 19(1): 487, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151421

RESUMO

BACKGROUND: Typhoid fever remains a major public health problem in Zimbabwe with recurrent outbreaks reported since 2009. To provide guidance on appropriate treatment choice in order to minimise the morbidity and mortality of typhoid fever and prevent large scale outbreaks, we investigated the antimicrobial susceptibility patterns, prevalence of Salmonella enterica serotype Typhi (S. Typhi) H58 haplotype and molecular subtypes of S. Typhi from outbreak strains isolated from 2009 to 2017 in Zimbabwe and compared these to isolates from neighbouring African countries. METHODS: Antimicrobial susceptibility testing was performed on all isolates using the disk diffusion, and E-Test, and results were interpreted using Clinical and Laboratory Standards Institute (CLSI) guidelines (2017). S. Typhi H58 haplotype screening was performed on 161 (58.3%) isolates. Pulsed-field gel electrophoresis (PFGE) was performed on 91 selected isolates across timelines using antibiotic susceptibility results and geographical distribution (2009 to 2016). RESULTS: Between 2009 and 2017, 16,398 suspected cases and 550 confirmed cases of typhoid fever were notified in Zimbabwe. A total of 276 (44.6%) of the culture-confirmed S. Typhi isolates were analysed and 243 isolates (88.0%) were resistant to two or more first line drugs (ciprofloxacin, ampicillin and chloramphenicol) for typhoid. The most common resistance was to ampicillin-chloramphenicol (172 isolates; 62.3%). Increasing ciprofloxacin resistance was observed from 2012 to 2017 (4.2 to 22.0%). Out of 161 screened isolates, 150 (93.2%) were haplotype H58. Twelve PFGE patterns were observed among the 91 isolates analysed, suggesting some diversity exists among strains circulating in Zimbabwe. PFGE analysis of 2013, 2014 and 2016 isolates revealed a common strain with an indistinguishable PFGE pattern (100% similarity) and indistinguishable from PFGE patterns previously identified in strains isolated from South Africa, Zambia and Tanzania. CONCLUSIONS: Resistance to first line antimicrobials used for typhoid fever is emerging in Zimbabwe and the multidrug resistant S. Typhi H58 haplotype is widespread. A predominant PFGE clone circulating in Zimbabwe, South Africa, Zambia and Tanzania, argues for cross-border cooperation in the control of this disease.


Assuntos
Salmonella typhi/genética , Salmonella typhi/isolamento & purificação , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia , Ampicilina/uso terapêutico , Antibacterianos/uso terapêutico , Cloranfenicol/uso terapêutico , Ciprofloxacino/uso terapêutico , Técnicas de Laboratório Clínico/estatística & dados numéricos , Surtos de Doenças , Resistência Microbiana a Medicamentos/genética , Eletroforese em Gel de Campo Pulsado , Feminino , Haplótipos , Humanos , Laboratórios/estatística & dados numéricos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Salmonella enterica/classificação , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Salmonella typhi/classificação , Sorogrupo , Febre Tifoide/diagnóstico , Febre Tifoide/tratamento farmacológico , Zimbábue/epidemiologia
7.
Onderstepoort J Vet Res ; 86(1): e1-e8, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31170784

RESUMO

Salmonellosis is a major threat facing the poultry industry globally. This study was conducted to investigate the level of Salmonella contaminations and determine the resistance pattern of isolates obtained from selected poultry farms in Kwara State, a transition state between southern and northern regions of Nigeria. A total of 900 samples were collected between January and August 2017, from the poultry environment, apparently including healthy and dead birds. Salmonella was isolated and identified using standard bacteriological methods. All presumptive Salmonella isolates were serotyped and tested for antimicrobial susceptibility using 11 different antimicrobials. A total of 58 (6.4%) Salmonella isolates were obtained, and the isolation rate was only statistically significant (p < 0.05) in live birds. The isolates comprised of 13 serovars. The three predominant serovars, Salmonella enterica ser. 6.7:d:- (29.0%), Salmonella Agama (28.0%) and Salmonella Typhimurium (16.0%), were isolated from all three sample types. Rare serovars like Salmonella Albany, Salmonella Colindale, Salmonella Istanbul, Salmonella Larochelle, Salmonella Nigeria and Salmonella Orion were also isolated in this study. A high frequency of resistance was generally observed with all the isolates exhibiting a total of (100%) resistance to ampicillin, cefotaxime and ceftazidime. This study documents the first predominant isolation of S. enterica ser. 6.7:d:- and S. Agama from chickens. It also documents the high frequency of fluoroquinolone and cephalosporins resistance of the isolates indicating the presence of selective pressure in the environment. Controls and targeted interventions against Salmonella and the frequent occurrence of antimicrobial resistance in chickens should be initiated to prevent the spread of this organism.


Assuntos
Criação de Animais Domésticos , Antibacterianos/farmacologia , Galinhas , Doenças das Aves Domésticas/epidemiologia , Salmonelose Animal/epidemiologia , Salmonella enterica/isolamento & purificação , Animais , Antibacterianos/uso terapêutico , Fazendas , Testes de Sensibilidade Microbiana/veterinária , Nigéria/epidemiologia , Doenças das Aves Domésticas/sangue , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , Prevalência , Salmonelose Animal/tratamento farmacológico , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Sorogrupo
8.
J Vet Med Sci ; 81(8): 1117-1120, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31231084

RESUMO

Our previous studies found that a dominant serovar of Salmonella enterica isolates from three farms raising broilers in 2014 and 2015 was serovar Agona and the number of Infantis isolates decreased (the serovar shift). In this study, 52 S. Agona strains which isolated between 1993 and 2008, were compared to the serovar shift clone by molecular epidemiology and phylogenetic analyses, using pulsed field gel electrophoresis and whole genome sequence analyses. Of the 52 strains, one strain isolated from a human case in 1995 was genetically identical to the serovar shift clone, even though it was isolated prior to the serovar shift. These results suggested that the S. Agona serovar shift clone had existed in a source other than chicken penetrated chicken population.


Assuntos
Galinhas , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Animais , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/veterinária , Humanos , Japão/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Infecções por Salmonella/microbiologia , Salmonelose Animal/epidemiologia , Salmonella enterica/genética , Estudos Soroepidemiológicos , Sorotipagem
9.
Emerg Infect Dis ; 25(7): 1377-1379, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31211677

RESUMO

Salmonella enterica serotype I 4,[5],12:i:- has been increasingly isolated from swine. However, its pathogenic potential is not well characterized. Analysis of swine cases confirmed a strong positive association between isolation of I 4,[5],12:i:- and lesions of enteric salmonellosis and suggested a similar pathogenic potential as that for Salmonella Typhimurium.


Assuntos
Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Doenças dos Suínos/microbiologia , Animais , Biópsia , Microbiologia de Alimentos , Humanos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Iowa/epidemiologia , Vigilância em Saúde Pública , Salmonelose Animal/diagnóstico , Salmonelose Animal/epidemiologia , Salmonella enterica/isolamento & purificação , Sorotipagem , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
10.
Microb Genom ; 5(7)2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31107206

RESUMO

Salmonella enterica serotype Kentucky can be a common causative agent of salmonellosis, usually associated with consumption of contaminated poultry. Antimicrobial resistance (AMR) to multiple drugs, including ciprofloxacin, is an emerging problem within this serotype. We used whole-genome sequencing (WGS) to investigate the phylogenetic structure and AMR content of 121 S.enterica serotype Kentucky sequence type 198 isolates from five continents. Population structure was inferred using phylogenomic analysis and whole genomes were compared to investigate changes in gene content, with a focus on acquired AMR genes. Our analysis showed that multidrug-resistant (MDR) S.enterica serotype Kentucky isolates belonged to a single lineage, which we estimate emerged circa 1989 following the acquisition of the AMR-associated Salmonella genomic island (SGI) 1 (variant SGI1-K) conferring resistance to ampicillin, streptomycin, gentamicin, sulfamethoxazole and tetracycline. Phylogeographical analysis indicates this clone emerged in Egypt before disseminating into Northern, Southern and Western Africa, then to the Middle East, Asia and the European Union. The MDR clone has since accumulated various substitution mutations in the quinolone-resistance-determining regions (QRDRs) of DNA gyrase (gyrA) and DNA topoisomerase IV (parC), such that most strains carry three QRDR mutations which together confer resistance to ciprofloxacin. The majority of AMR genes in the S. enterica serotype Kentucky genomes were carried either on plasmids or SGI structures. Remarkably, each genome of the MDR clone carried a different SGI1-K derivative structure; this variation could be attributed to IS26-mediated insertions and deletions, which appear to have hampered previous attempts to trace the clone's evolution using sub-WGS resolution approaches. Several different AMR plasmids were also identified, encoding resistance to chloramphenicol, third-generation cephalosporins, carbapenems and/or azithromycin. These results indicate that most MDR S. enterica serotype Kentucky circulating globally result from the clonal expansion of a single lineage that acquired chromosomal AMR genes 30 years ago, and has continued to diversify and accumulate additional resistances to last-line oral antimicrobials. This article contains data hosted by Microreact.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Salmonella/microbiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , DNA Bacteriano/genética , Ilhas Genômicas/genética , Genômica , Humanos , Filogenia , Plasmídeos/genética , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Sorogrupo , Sequenciamento Completo do Genoma/métodos
11.
BMC Bioinformatics ; 20(1): 215, 2019 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-31029079

RESUMO

BACKGROUND: Salmonella enterica is a major cause of bacterial food-borne disease worldwide. Immunological serotyping is the most commonly used typing method to characterize S. enterica isolates, but is time-consuming and requires expensive reagents. Here, we developed an R package CSESA (CRISPR-based Salmonella enterica Serotype Analyzer) to predict the serotype based on the CRISPR loci of S. enterica. RESULTS: CSESA has implemented the CRISPR typing method CLSPT and extended its coverage on diverse S. enterica serotypes. This package takes CRISPR sequences or the genome sequences as input and provides users with the predicted serotypes. CSESA has shown excellent performance with currently available sequences of S. enterica. CONCLUSIONS: CSESA is a convenient and useful tool for the prediction of S. enterica serotypes. The application of CSESA package can improve the efficiency of serotyping for S. enterica and reduce the burden of manpower resources. CSESA is freely available from CRAN at https://cran.r-project.org/web/packages/CSESA/ .


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Salmonella enterica/classificação , Interface Usuário-Computador , Reação em Cadeia da Polimerase , Sorogrupo , Sorotipagem/métodos
12.
Can J Microbiol ; 65(7): 477-485, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30865841

RESUMO

Salmonella enterica serovar Heidelberg causes foodborne infections and is a major threat to the food chain and public health. In this study, we aimed to develop a rapid molecular typing approach to identify Salmonella enterica serovar Heidelberg. Using comparative genomics, four serovar-specific gene fragments were identified, and a real-time polymerase chain reaction (PCR) combined with a propidium monoazide (PMA) pretreatment method was developed for simultaneous detection of viable Salmonella sp. (invA) and Salmonella Heidelberg (SeHA_C3258). The assay showed 100% specificity for all strains tested. The assay was able to distinguish effectively viable or dead cells with the PMA. The detection limit was 2.4 CFU/mL following 6 h of incubation in enrichment Luria-Bertani medium, and the assay could detect 1.7 × 102 CFU/mL in the presence of pork background flora. In artificially contaminated pork, real-time PCR detected inoculum levels of 1.15 CFU/25 g of pork after a 6 h enrichment. Thus, our findings indicated that this comparative genomics approach could be used to screen for serovar-specific fragments and that real-time PCR with PMA was a simple and reliable method for detecting viability of Salmonella species and Salmonella Heidelberg.


Assuntos
Azidas , Tipagem Molecular/métodos , Propídio/análogos & derivados , Reação em Cadeia da Polimerase em Tempo Real/métodos , Carne Vermelha/microbiologia , Salmonella enterica/isolamento & purificação , Animais , Microbiologia de Alimentos , Salmonella enterica/classificação , Salmonella enterica/genética , Suínos
13.
Emerg Microbes Infect ; 8(1): 29-39, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30866757

RESUMO

Emergence of multidrug-resistant (MDR) Salmonella enterica serovar Indiana (S. Indiana), a dominant Salmonella serovar in China, has raised global awareness because the MDR S. Indiana also was rapidly emerged in other countries recently. To improve our understanding of underlying MDR mechanism and evolution of this emerging zoonotic pathogen, here we examined the standard ATCC51959 strain together with 19 diverse and representative Chinese S. Indiana strains by performing comprehensive microbiological, molecular, and comparative genomics analyses. The findings from S1-PFGE, plasmid origin analysis and Southern blotting suggested the MDR phenotype in the majority of isolates was associated with large integron-carrying plasmids. Interestingly, further in-depth analyses of two recently isolated, plasmid-free MDR S. Indiana revealed a long chromosomal class I integron (7.8 kb) that is not linked to the Salmonella Genome Island 1 (SGI1), which is rare. This unique chromosomal integron shares extremely high similarity to that identified in a MDR E. coli plasmid pLM6771 with respect to both genomic organization and sequence identity. Taken together, both plasmid and chromosomal integron I exist in the examined MDR S. Indiana strains. This timely study represents a significant step toward the understanding of molecular basis of the emerging MDR S. Indiana.


Assuntos
Cromossomos Bacterianos/genética , Farmacorresistência Bacteriana Múltipla , Integrons , Plasmídeos/genética , Salmonella enterica/genética , Animais , Antibacterianos/farmacologia , China , Genes Bacterianos , Genômica , Humanos , Testes de Sensibilidade Microbiana , Tipagem Molecular , Filogenia , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Sorogrupo
14.
Pathog Glob Health ; 113(1): 20-26, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30722761

RESUMO

Non-typhoidal Salmonella (NTS) are foodborne pathogens that are responsible for self-limiting gastroenteritis in humans. The present study aims at the molecular characterisation and comparative genomics of Salmonella enterica serovar Senftenberg strain P5558 isolated from the pus samples of a patient suffering from stump infection. The isolate was subjected to serotyping and antimicrobial susceptibility test to understand the phenotypical characteristics. Whole genome sequencing (WGS) was carried out and comparative genomics using computational tools showed the antimicrobial resistance and virulence gene profile of the isolates from the genome sequence data. Typing experiments confirmed that the isolate belong to S. Senftenberg with sequence type ST14. Resistance against ß-lactams is associated with the presence of blaTEM-1, blaOXA-9, blaCMY-2 and blaNDM-1 genes. Similarly resistance to aminoglycoside was associated with five aminoglycoside modifying enzymes aac(6')-Ia, aac(6')-Ib, aph(3')-Ib, aph(6')-Ib and ant(3'')-Ia, sulfonamide with sul-1 and sul-2 and chloramphenicol with florR gene. Substitutions in gyrA (S83Y, D87G) and parC (S80I) genes found to be the reason for fluoroquinolone resistance. The plasmid profiling showed the isolate has four resistance plasmids in which plasmid p5558-NDM (IncA/C) harbours major resistance genes including blaNDM-1 and blaCMY-2. Determination of virulence gene profile revealed that the genome carries all major Salmonella pathogenicity islands and virulence factors. From our findings it is clear that the isolate possess characteristic pathogenicity islands (SPI 1-6, 13, 14), major virulence factors and acquired resistance genes. Comparative analysis suggests the evolution and distribution of the MDR gene encoding plasmids in NTS.


Assuntos
Infecções por Salmonella/microbiologia , Salmonella enterica/genética , beta-Lactamases/genética , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Genes MDR/genética , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Fosfoproteínas/genética , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/patogenicidade , Sorotipagem/métodos , Virulência/genética , Fatores de Virulência/genética , Sequenciamento Completo do Genoma/métodos , Adulto Jovem
15.
Clin Microbiol Rev ; 32(1)2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30487167

RESUMO

The ability of pathogenic bacteria to affect higher organisms and cause disease is one of the most dramatic properties of microorganisms. Some pathogens can establish transient colonization only, but others are capable of infecting their host for many years or even for a lifetime. Long-term infection is called persistence, and this phenotype is fundamental for the biology of important human pathogens, including Helicobacter pylori, Mycobacterium tuberculosis, and Salmonella enterica Both typhoidal and nontyphoidal serovars of the species Salmonella enterica can cause persistent infection in humans; however, as these two Salmonella groups cause clinically distinct diseases, the characteristics of their persistent infections in humans differ significantly. Here, following a general summary of Salmonella pathogenicity, host specificity, epidemiology, and laboratory diagnosis, I review the current knowledge about Salmonella persistence and discuss the relevant epidemiology of persistence (including carrier rate, duration of shedding, and host and pathogen risk factors), the host response to Salmonella persistence, Salmonella genes involved in this lifestyle, as well as genetic and phenotypic changes acquired during prolonged infection within the host. Additionally, I highlight differences between the persistence of typhoidal and nontyphoidal Salmonella strains in humans and summarize the current gaps and limitations in our understanding, diagnosis, and curing of persistent Salmonella infections.


Assuntos
Infecções por Salmonella/microbiologia , Salmonella enterica/patogenicidade , Portador Sadio , Humanos , Fatores de Risco , Infecções por Salmonella/diagnóstico , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/patologia , Salmonella enterica/classificação , Sorogrupo
16.
Jpn J Infect Dis ; 72(1): 38-43, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30270249

RESUMO

We investigated the prevalence of Salmonella in 227 small red-eared sliders (Trachemys scripta elegans) from 2006 to 2008. A total of 130 turtles (57.3%) tested positive for S. enterica subsp. enterica. Twenty-two serotypes including S. Montevideo, S. Newport, S. Pomona, S. Braenderup, S. Sandiego, and S. Litchfield were identified. Salmonella strains with closely related pulsed field gel electrophoresis (PFGE) patterns were isolated from several shops located in different areas from 2006 to 2008. Antimicrobial resistance was detected among strains of S. Montevideo, S. Newport, S. Braenderup, S. Sandiego, and S. Litchfield. The relatedness of antimicrobial resistance and PFGE profiles was not observed. The PFGE patterns of S. Poona strains isolated in 2006 and 2008 and the causative strains of turtle-associated salmonellosis in 2006 were identical. These results revealed a high prevalence of Salmonella enterica subsp. enterica in red-eared sliders retailed in Japan. In addition, genetically closely-related strains of turtle-associated Salmonella were repeatedly introduced into Japan over the study period and were distributed widely in Japan. These Salmonella strains present a risk of a widely disseminated outbreak of turtle-associated salmonellosis.


Assuntos
Animais de Estimação/microbiologia , Salmonelose Animal/diagnóstico , Salmonelose Animal/epidemiologia , Infecções por Salmonella/epidemiologia , Salmonella enterica/fisiologia , Tartarugas/microbiologia , Animais , Farmacorresistência Bacteriana , Humanos , Japão/epidemiologia , Prevalência , Infecções por Salmonella/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/classificação , Salmonella enterica/imunologia , Sorogrupo
17.
Environ Res ; 168: 7-13, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30253315

RESUMO

The Delmarva Peninsula, a major agricultural and recreational region for the U.S. states of Delaware, Maryland and Virginia, experiences recurrent salmonellosis disease. Previous studies point to water environments as a potential persistent environmental reservoir of Salmonella enterica. To evaluate this hypothesis, water from the four main rivers of the Maryland Eastern Shore on the Delmarva Peninsula was tested for the presence of S. enterica, and recovered isolates were characterized for antimicrobial resistance. Sampling was performed in autumn and spring to evaluate temporal persistence at twenty four sites along the Choptank, Nanticoke, Pocomoke and Wicomico Rivers. Water (10 L) was filtered through sterile modified Moore swabs in situ. Swabs were selectively enriched for S. enterica and presumptive salmonellae were confirmed by PCR amplification of the Salmonella-specific invA and hilA genes. The serogroup of 402 isolates was determined, followed by serotype characterization for 157 isolates selected to represent all the identified serogroups across all samples. S. enterica was isolated from all the rivers in both seasons and was detected in 35/46 (65%) of surface water samples, with equivalent recovery in spring (70%) and fall (61%). The likelihood of isolating S. enterica was higher for the Nanticoke and Pocomoke Rivers, χ2 (3, N = 46) = 12.75, p < 0.01. In total, 18 serotypes of S. enterica were identified, and serotype diversity differed between the fall and spring samplings. Newport was the most frequently isolated serotype, both overall and in the fall, identified in 8/46 samples (17%). Typhimurium was the predominant serotype in spring. Some temporal and biogeographic patterns were observed in S. enterica recovery, but 6/18 serotypes were identified in both seasons. The majority (84%) of isolates were pan-susceptible, including all those tested from the Wicomico River (N = 19). Twenty five isolates (16%) from 9 samples were resistant to at least one antimicrobial, including serotypes Typhimurium, Newport, Litchfield, III 17:z10: e,n,x,z15, III 60:I and IV_40:z4: z32: -. Of the isolates that were resistant to a single antimicrobial (N = 12), resistance was to streptomycin or sulfisoxazole. Thirteen isolates were multidrug resistant, nine exhibiting resistance to ampicillin, sulfisoxazole, tetracycline, amoxicillin/clavulanic acid, cefoxitin and ceftriaxone, and four to sulfisoxazole and tetracycline. The widespread presence and diversity of S. enterica in Delmarva rivers are concerning given the frequent use of rivers and tributaries as a source of irrigation and for recreation. Future research should seek to determine specific point sources of S. enterica for surface river waters, and risks associated with acquisition of antimicrobial resistance traits.


Assuntos
Reservatórios de Doenças , Farmacorresistência Bacteriana Múltipla , Salmonella enterica , Antibacterianos , Delaware , Reservatórios de Doenças/microbiologia , Resistência a Múltiplos Medicamentos , Maryland , Testes de Sensibilidade Microbiana , Rios , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Sorogrupo , Virginia
18.
BMC Microbiol ; 18(1): 225, 2018 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-30587131

RESUMO

BACKGROUND: Pullorum disease, caused by Salmonella enterica serovar Pullorum (S. Pullorum), is one of the most important bacterial infections in the poultry industry in developing countries, including China. To examine the prevalence and characteristics of S. Pullorum, the Multilocus Sequence Typing (MLST) genotypes, fluoroquinolones resistance, and biofilm-forming abilities of S. Pullorum isolates were investigated, collected from 2011 to 2016 in China. RESULTS: Thirty S. Pullorum isolates collected from 2011 to 2016 were analyzed. Quinolones susceptibility testing showed that 90% of the isolates were resistant to the first generation of quinolines nalidixic acid, but the resistance rates to different fluoroquinolones agents were lower than 13.3%; for some there was even no resistance. Multilocus sequence typing (MLST) showed that ST-92 was the dominating genotype, accounting for 90.0% of all S. pullorum strains. The remaining three isolates were of the new reported sequence type ST-2151. Interestingly, the Asp87Gly substitution in quinolone resistance-determining regions (QRDR) of GyrA was only observed in the three strains of ST-2151, suggesting a potential correlation between Asp87Gly substitution and sequence type (p < 0.05). However, Asp87Gly substitution could not confer the resistant to ofloxacin and ciprofloxacin of these isolates. The plasmid-mediated quinolone resistance (PMQR) gene was not found in any of the tested isolates. Furthermore, an assay measuring biofilm-forming abilities showed that 46.7% of the isolates were non-biofilm producers, while 53.3% could form very weak biofilms, which might explain the relatively lower resistance to fluoroquinolones. CONCLUSIONS: We reported a high resistance rate to the first generation of quinolines nalidixic acid and relatively low resistance rates to fluoroquinolones in S. Pullorum isolates. In addition, weak biofilm-forming abilities were found, which might be an important reason of the low fluoroquinolones resistance rates of S. Pullorum isolates. ST-92 was the dominating genotype demonstrated by MLST, and the new sequence type ST-2151 showed a potential correlation with Asp87Gly substitution in QRDR of GyrA. We believe the characterization of these S. Pullorum isolates will be helpful to develop prevention and control strategies.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Doenças das Aves Domésticas/microbiologia , Quinolonas/farmacologia , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , Galinhas , China , Ciprofloxacino/farmacologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fenótipo , Salmonella enterica/classificação , Salmonella enterica/isolamento & purificação , Sorogrupo
19.
Emerg Infect Dis ; 24(12): 2284-2291, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30457533

RESUMO

Extended-spectrum ß-lactamases (ESBLs) confer resistance to clinically important third-generation cephalosporins, which are often used to treat invasive salmonellosis. In the United States, ESBLs are rarely found in Salmonella. However, in 2014, the US Food and Drug Administration found blaCTX-M-65 ESBL-producing Salmonella enterica serotype Infantis in retail chicken meat. The isolate had a rare pulsed-field gel electrophoresis pattern. To clarify the sources and potential effects on human health, we examined isolates with this pattern obtained from human surveillance and associated metadata. Using broth microdilution for antimicrobial susceptibility testing and whole-genome sequencing, we characterized the isolates. Of 34 isolates, 29 carried the blaCTX-M-65 gene with <9 additional resistance genes on 1 plasmid. Of 19 patients with travel information available, 12 (63%) reported recent travel to South America. Genetically, isolates from travelers, nontravelers, and retail chicken meat were similar. Expanded surveillance is needed to determine domestic sources and potentially prevent spread of this ESBL-containing plasmid.


Assuntos
Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella enterica/classificação , beta-Lactamases/genética , DNA Bacteriano , Humanos , Filogenia , Filogeografia , Polimorfismo Genético , Salmonella enterica/genética , Sorogrupo , Estados Unidos/epidemiologia
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