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Salmonella spp. is a common zoonotic pathogen, causing gastrointestinal infections in people. Pigs and pig meat are a major source of infection. Although farm biosecurity is believed to be important for controlling Salmonella transmission, robust evidence is lacking on which measures are most effective. This study enrolled 250 pig farms across nine European countries. From each farm, 20 pooled faecal samples (or similar information) were collected and analysed for Salmonella presence. Based on the proportion of positive results, farms were categorised as at higher or lower Salmonella risk, and associations with variables from a comprehensive questionnaire investigated. Multivariable analysis indicated that farms were less likely to be in the higher-risk category if they had '<400 sows'; used rodent baits close to pig enclosures; isolated stay-behind (sick) pigs; did not answer that the hygiene lock/ anteroom was easy to clean; did not have a full perimeter fence; did apply downtime of at least 3 days between farrowing batches; and had fully slatted flooring in all fattener buildings. A principal components analysis assessed the sources of variation between farms, and correlation between variables. The study results suggest simple control measures that could be prioritised on European pig farms to control Salmonella.
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Salmonelose Animal , Doenças dos Suínos , Suínos , Animais , Feminino , Fazendas , Biosseguridade , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle , Salmonella , Europa (Continente)/epidemiologia , Salmonelose Animal/epidemiologia , Salmonelose Animal/prevenção & controle , Criação de Animais Domésticos/métodosRESUMO
Different species of Shewanella spp. widely inhabit freshwater and marine environments. Some of them are opportunistic fish pathogens. The application of high-throughput sequencing enabled the characterization and taxonomic reclassification of many Shewanella spp. species. Still, some strains collected from fish need to be better recognized. The aim of the present study was to classify and determine the phylogenetic relationships of Shewanella spp. collected from fish. The complete genomes of 94 strains of Shewanella spp. from different fish species were sequenced using Illumina platform (MiSeq). The 16S rRNA gene, genomic features and whole-genome relationships of those bacteria were comprehensively analysed in comparison to reference strains. Whole-genome analysis showed that the tested Shewanella spp. strains were clustered into six groups similar to reference strains of S. xiamenensis, S. oneidensis, S. glacialipiscicola, S. hafniensis, S. baltica and S. oncorhynchi. Our study indicates that the whole-genome sequence analysis enabled taxonomic classification and assessment of the diversity of the Shewanella spp. strains, as opposed to recently the gold standard method of 16S rRNA amplicon sequencing. The high genetic diversity and low similarity to the reference genome of S. oneidensis indicate that the group of strains may be a subspecies or even new species. Furthermore, we showed that the most frequent Shewanella spp. species occurring in freshwater fish in our study is the recently described species S. oncorhynchi.
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OBJECTIVES: The occurrence and zoonotic potential of antimicrobial resistance (AMR) in pigs and broilers has been studied intensively in past decades. Here, we describe AMR levels of European pig and broiler farms and determine the potential risk factors. METHODS: We collected faeces from 181 pig farms and 181 broiler farms in nine European countries. Real-time quantitative PCR (qPCR) was used to quantify the relative abundance of four antimicrobial resistance genes (ARGs) [aph(3')-III, erm(B), sul2 and tet(W)] in these faeces samples. Information on antimicrobial use (AMU) and other farm characteristics was collected through a questionnaire. A mixed model using country and farm as random effects was performed to evaluate the relationship of AMR with AMU and other farm characteristics. The correlation between individual qPCR data and previously published pooled metagenomic data was evaluated. Variance component analysis was conducted to assess the variance contribution of all factors. RESULTS: The highest abundance of ARG was for tet(W) in pig faeces and erm(B) in broiler faeces. In addition to the significant positive association between corresponding ARG and AMU levels, we also found on-farm biosecurity measures were associated with relative ARG abundance in both pigs and broilers. Between-country and between-farm variation can partially be explained by AMU. Different ARG targets may have different sample size requirements to represent the overall farm level precisely. CONCLUSIONS: qPCR is an efficient tool for targeted assessment of AMR in livestock-related samples. The AMR variation between samples was mainly contributed to by between-country, between-farm and within-farm differences, and then by on-farm AMU.
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Antibacterianos , Anti-Infecciosos , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Galinhas , Farmacorresistência Bacteriana , Fazendas , Fezes , Fatores de Risco , SuínosRESUMO
BACKGROUND: Real-time quantitative PCR (qPCR) is an affordable method to quantify antimicrobial resistance gene (ARG) targets, allowing comparisons of ARG abundance along animal production chains. OBJECTIVES: We present a comparison of ARG abundance across various animal species, production environments and humans in Europe. AMR variation sources were quantified. The correlation of ARG abundance between qPCR data and previously published metagenomic data was assessed. METHODS: A cross-sectional study was conducted in nine European countries, comprising 9572 samples. qPCR was used to quantify abundance of ARGs [aph(3')-III, erm(B), sul2, tet(W)] and 16S rRNA. Variance component analysis was conducted to explore AMR variation sources. Spearman's rank correlation of ARG abundance values was evaluated between pooled qPCR data and earlier published pooled metagenomic data. RESULTS: ARG abundance varied strongly among animal species, environments and humans. This variation was dominated by between-farm variation (pigs) or within-farm variation (broilers, veal calves and turkeys). A decrease in ARG abundance along pig and broiler production chains ('farm to fork') was observed. ARG abundance was higher in farmers than in slaughterhouse workers, and lowest in control subjects. ARG abundance showed a high correlation (Spearman's ρâ>â0.7) between qPCR data and metagenomic data of pooled samples. CONCLUSIONS: qPCR analysis is a valuable tool to assess ARG abundance in a large collection of livestock-associated samples. The between-country and between-farm variation of ARG abundance could partially be explained by antimicrobial use and farm biosecurity levels. ARG abundance in human faeces was related to livestock antimicrobial resistance exposure.
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Antibacterianos , Anti-Infecciosos , Animais , Antibacterianos/farmacologia , Bovinos , Galinhas , Estudos Transversais , Farmacorresistência Bacteriana , Fezes , Genes Bacterianos , Humanos , Gado , Carne , RNA Ribossômico 16S/genética , SuínosRESUMO
Livestock feces with antimicrobial resistant bacteria reaches the farm floor, manure pit, farm land and wider environment by run off and aerosolization. Little research has been done on the role of dust in the spread of antimicrobial resistance (AMR) in farms. Concentrations and potential determinants of antimicrobial resistance genes (ARGs) in farm dust are at present not known. Therefore in this study absolute ARG levels, representing the levels people and animals might be exposed to, and relative abundances of ARGs, representing the levels in the bacterial population, were quantified in airborne farm dust using qPCR. Four ARGs were determined in 947 freshly settled farm dust samples, captured with electrostatic dustfall collectors (EDCs), from 174 poultry (broiler) and 159 pig farms across nine European countries. By using linear mixed modeling, associations with fecal ARG levels, antimicrobial use (AMU) and farm and animal related parameters were determined. Results show similar relative abundances in farm dust as in feces and a significant positive association (ranging between 0.21 and 0.82) between the two reservoirs. AMU in pigs was positively associated with ARG abundances in dust from the same stable. Higher biosecurity standards were associated with lower relative ARG abundances in poultry and higher relative ARG abundances in pigs. Lower absolute ARG levels in dust were driven by, among others, summer season and certain bedding materials for poultry, and lower animal density and summer season for pigs. This study indicates different pathways that contribute to shaping the dust resistome in livestock farms, related to dust generation, or affecting the bacterial microbiome. Farm dust is a large reservoir of ARGs from which transmission to bacteria in other reservoirs can possibly occur. The identified determinants of ARG abundances in farm dust can guide future research and potentially farm management policy.
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Farmacorresistência Bacteriana , Poeira , Fazendas , Animais , Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana/genética , Poeira/análise , Europa (Continente) , SuínosRESUMO
This study was conducted to evaluate the performance of a screening protocol to detect and isolate mcr-positive Escherichia coli and Salmonella spp. from animal caecal content and meat samples. We used a multicentre approach involving 12 laboratories from nine European countries. All participants applied the same methodology combining a multiplex PCR performed on DNA extracted from a pre-enrichment step, followed by a selective culture step on three commercially available chromogenic agar plates. The test panel was composed of two negative samples and four samples artificially contaminated with E. coli and Salmonella spp. respectively harbouring mcr-1 or mcr-3 and mcr-4 or mcr-5 genes. PCR screening resulted in a specificity of 100% and a sensitivity of 83%. Sensitivity of each agar medium to detect mcr-positive colistin-resistant E. coli or Salmonella spp. strains was 86% for CHROMID® Colistin R, 75% for CHROMagarTM COL-APSE and 70% for COLISTIGRAM. This combined method was effective to detect and isolate most of the E. coli or Salmonella spp. strains harbouring different mcr genes from food-producing animals and food products and might thus be used as a harmonized protocol for the screening of mcr genes in food-producing animals and food products in Europe.
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Escherichia coli , Carne , Salmonella , Ágar , Animais , Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/genética , Carne/microbiologia , Testes de Sensibilidade Microbiana , Plasmídeos , Salmonella/isolamento & purificaçãoRESUMO
Different Shewanella species are isolated both from healthy and from diseased fish. To date, contemporary methods do not provide sufficient insight to determine species and detail differentiation between tested strains. Bacteria isolated from cultured (n = 33), wild (n = 12) and ornamental (n = 6) fish, as well as several reference strains, were tested by 16S rRNA gene sequencing, ERIC-PCR and pulsed-field gel electrophoresis (PFGE) assays. Our study indicates that isolates collected from freshwater fish were genetically diverse. Based on 16S rRNA gene sequences, bacteria were clustered into groups S. putrefaciens, S. xiamenensis and S. oneidensis. Some isolates were classified only to genus Shewanella; thus, 16S rRNA gene analyses were not enough to determine the species. ERIC-PCR revealed 49 different genotype profiles indicating that the method might be useful for differentiation of Shewanella isolates irrespectively to species identification, contrary to PFGE which is not suitable for Shewanella typing.
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Peixes/microbiologia , Variação Genética , Genótipo , Shewanella/genética , Animais , Eletroforese em Gel de Campo Pulsado/veterinária , Água Doce , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Análise de Sequência de RNA/veterináriaRESUMO
The aim of this study was to estimate virulence potential of Salmonella enterica strains colonizing the gut of free-living sand lizards (Lacerta agilis L.). The strains belonged to three Salmonella serovars: Abony, Schleissheim, and Telhashomer. Adhesion and invasion abilities of the strains were determined in quantitative assays using the gentamicin protection method. Induction of apoptosis was assessed using HeLa cell monolayers. PCR assays were used for detection of 26 virulence genes localised within mobile elements: pathogenicity islands, virulence plasmids, and prophage sequences. In vitro studies revealed that all strains had adhesion and invasion abilities to human epithelial cells. The isolates were cytotoxic and induced apoptosis of the cells. The serovars differed in the number of virulence-associated genes: up to 18 genes were present in Salmonella Schleissheim, 17 in Salmonella Abony, whereas as few as six genes were found in Salmonella Telhashomer. Generally, Salmonella Abony and Salmonella Schleissheim did not differ much in gene content connected with the presence SPI-1 to -5. All of the strains lacked genes localised within bacteriophages and plasmids. The presence of virulence-associated genes and in vitro pathogenicity assays suggest that Salmonella sp. strains originating from autochthonous, free-living lizards can potentially infect and cause disease in humans.
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Lagartos/microbiologia , Salmonella enterica/classificação , Animais , Animais Selvagens , Aderência Bacteriana , Células HeLa , Humanos , Salmonelose Animal/microbiologia , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Salmonella enterica/patogenicidade , Sorogrupo , Virulência/genéticaRESUMO
Background: The newest method of treatment for patients with NSCLC (non-small cell lung cancer) is immunotherapy directed at the immune checkpoints PD-1 (Programmed Cell Death 1) and PD-L1 (Programmed Cell Death Ligand 1). PD-L1 is the only validated predictor factor for immunotherapy efficacy, but it is imperfect. Some patients do not benefit from immunotherapy and may develop primary or secondary resistance. This study aimed to assess the intestinal resistome composition of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors in the context of clinical features and potentially new prediction factors for assessing immunotherapy efficacy. Methods: The study included 30 advanced NSCLC patients, 19 (57%) men and 11 (33%) women treated with first- or second-line immunotherapy (nivolumab, pembrolizumab or atezolizumab). We evaluated the patient's gut resistome composition using the high sensitivity of targeted metagenomics. Results: Studies have shown that resistome richness is associated with clinical and demographic factors of NSCLC patients treated with immunotherapy. Smoking seems to be associated with an increased abundance of macrolides, lincosamides, streptogramins and vancomycin core resistome. The resistome of patients with progression disease appears to be more abundant and diverse, with significantly higher levels of genomic markers of resistance to lincosamides (lnuC). The resistance genes lnuC, msrD, ermG, aph(6), fosA were correlated with progression-free survival or/and overall survival, thus may be considered as factors potentially impacting the disease. Conclusion: The results indicate that the intestinal resistome of NSCLC patients with immune checkpoint inhibitors treatment differs depending on the response to immunotherapy, with several distinguished markers. Since it might impact treatment efficacy, it must be examined more deeply.
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Since Salmonella serotyping according to the White-Kauffmann-Le Minor scheme fails to identify rough and atypical serological variants, this study aimed at improving serovar identification with the commercially available Premi®Test Salmonella Assay. The array was validated against a set of Salmonella reference strains (n = 27) and field isolates of known serological structure (n = 112) showing up to 97.8% congruent results. Its diagnostic suitability was further verified with random field isolates (n = 52; 100% congruence). For 'rough' isolates (n = 54) and those with antigen expression failure (n = 19) the assay showed, respectively, 98.1% and 73.7% of serovar recognition. It considerably improved diagnostic capacity while typing troublesome isolates such as those failing to express flagellar antigens or showing autoagglutination. The method offers lower labour time compared to the traditional serotyping and does not require a broad range of diagnostic sera.
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Salmonella , Sorotipagem , AnimaisRESUMO
Monophasic Salmonella Typhimurium (1,4,[5],12:i:-) is one of the leading Salmonella serovars causing human salmonellosis in Europe. It has been observed in Poland since 2008. This serovar is considered the one with the highest rate of mcr prevalence. This report presents a sequence characteristic of the multidrug-resistant (MDR) monophasic S. Typhimurium isolated from a pig faecal sample with the confirmed presence of the mcr-1.1 gene. The genome was assembled into the complete chromosome and 4 plasmids: IncHI2 (232 119 bp), IncFIB/IncFIC (133 901 bp), ColRNAI (6659 bp), and Col8282 (4066bp). The strain identified as ST34 carried multiple antimicrobial resistance genes located both on chromosome (tet(B)) and plasmids: mcr-1.1 and blaTEM-1B on ST4-IncHI2, and mef(B), blaTEM-1B, aadA1, qacL, dfrA12, aadA2, cmlA1, sul3, tet(M) on IncFIB/FIC. The mcr-1.1 gene was previously identified in E. coli deriving mainly from poultry, but this is the first case of the occurrence of mcr-positive Salmonella in Poland. The obtained results of analysis of the genome content draw attention to the problem of multidrug-resistant pathogens, especially in the context of resistance to colistin which is a last-resort antimicrobial.
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Escherichia coli , Salmonella typhimurium , Animais , Colistina/farmacologia , Escherichia coli/genética , Polônia , Salmonella typhimurium/genética , Sorogrupo , SuínosRESUMO
Enterococci as opportunistic bacteria are important for human health. Due to the prevalence and ease of acquisition and transfer of their genes, they are an excellent indicator of environmental contamination and the spread of antimicrobial resistance. The aim of the study was to assess the prevalence of Enterococcus spp. in wild birds in Poland, determination of antimicrobial susceptibility and WGS analysis of Enterococcus (E.) faecium and E. faecalis. For this purpose, 138 samples from various species of free-living birds were tested, with 66.7% positive results. Fourteen species were detected, with E. faecalis being the most common, followed by E. casseliflavus and E. hirae. In antimicrobial susceptibility testing, 10.0% of E. faecalis and 50.0% of E. faecium showed resistance to one antimicrobial agent, in addition the MDR phenotype which was found in one E. faecium. The most common resistance phenotype included tetracycline and quinupristin/dalfopristin. The WGS analysis confirmed the significant advantage of the virulence gene diversity of E. faecalis strains over E. faecium. In addition, plasmid replicons were found in 42.0% of E. faecalis and 80.0% of E. faecium. The obtained results confirm free-living birds can be a reservoir of Enterococcus spp. with a considerable zoonotic potential.
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The epidemiological role of monophasic Salmonella enterica subsp. enterica serovar Typhimurium tends to increase, indicating pandemic spread. The aim of the present study was to confirm the occurrence of this serological variant in Poland and to report the first cases in Belarus and Ukraine. Genetic similarity of monophasic isolates with Salmonella Typhimurium already present in these countries was assessed. Serotyping, duplex-polymerase chain reaction (PCR) assay, antibiotic resistance and pulsed-field gel electrophoresis (PFGE) profiling have been used to meet the study objectives. Monophasic Salmonella Typhimurium was found at low frequency in various sources along the food chain, including feed, animals, meat, and sewage sludge. The first isolates date back to 2008. The clones observed in other European countries were found, along with a number of new, unrelated genetic lineages appearing locally in three countries. Monophasic Salmonella Typhimurium is claimed to replace and discontinue the domination of pentaresistant Salmonella Typhimurium. Pigs and pork are assumed to be the main vectors of monophasic Salmonella Typhimurium, but their relevance for public health is limited.
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Antibacterianos/farmacologia , Carne/microbiologia , Salmonelose Animal/epidemiologia , Salmonella typhimurium/isolamento & purificação , Ração Animal/microbiologia , Animais , Bovinos , Galinhas , Análise por Conglomerados , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Eletroforese em Gel de Campo Pulsado , Gansos , Humanos , Testes de Sensibilidade Microbiana , Polônia/epidemiologia , Reação em Cadeia da Polimerase , República de Belarus/epidemiologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/classificação , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Sorotipagem , Esgotos/microbiologia , Suínos , Perus , Ucrânia/epidemiologiaRESUMO
This paper describes a fatal case of nontuberculosis mycobacteriosis in a four-year-old brown caiman kept in captivity. Although the clinical signs were asymptomatic, severe gross lesions were observed, namely necrotic inflammation of the intestines and granulomatous hepatitis. Microbiological and histopathological examination performed on the tissues collected postmortem revealed a mixed infection of Mycobacterium lentiflavum and Mycobacterium szulgai, secondarily mimicked with Salmonella Coeln, Aeromonas hydrofila, Citrobacter freundii, and Providencia rettgeri. Those microorganisms are not only potentially pathogenic to reptiles, but also have a zoonotic importance for humans. Our findings clearly demonstrate the importance of educating owners and maintaining hygiene rules when handling reptiles.
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Salmonella enterica subsp. enterica serovar Dublin (S. Dublin) is a zoonotic pathogen causing infections in animals, especially in cattle. In this study, we report draft genome sequences of four S. Dublin isolated between 1956 and 1957 from cattle and fox in Poland. Whole genome sequencing was performed on the Illumina platform and the data is available at National Center for Biotechnology Information under the BioProject accession number PRJNA865912. In order to better understand the genetic basis of epidemiology of S. Dublin infection, the obtained sequences were analyzed using the tools which are available at Center of Genomic Epidemiology (https://www.genomicepidemiology.org/) including core genome multilocus sequence typing (cgMLST) and core genome single nucleotide polymorphisms (cgSNPs).
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Introduction: Factors other than PD-L1 (Programmed Death Ligand 1) are being sought as predictors for cancer immuno- or chemoimmunotherapy in ongoing studies and long-term observations. Despite high PD-L1 expression on tumor cells, some patients do not benefit from immunotherapy, while others, without the expression of this molecule, respond to immunotherapy. Attention has been paid to the composition of the gut microbiome as a potential predictive factor for immunotherapy effectiveness. Materials and Methods: Our study enrolled 47 Caucasian patients with stage IIIB or IV non-small cell lung cancer (NSCLC). They were eligible for treatment with first- or second-line immunotherapy or chemoimmunotherapy. We collected stool samples before the administration of immunotherapy. We performed next-generation sequencing (NGS) on DNA isolated from the stool sample and analyzed bacterial V3 and V4 of the 16S rRNA gene. Results: We found that bacteria from the families Barnesiellaceae, Ruminococcaceae, Tannerellaceae, and Clostridiaceae could modulate immunotherapy effectiveness. A high abundance of Bacteroidaaceae, Barnesiellaceae, and Tannerellaceae could extend progression-free survival (PFS). Moreover, the risk of death was significantly higher in patients with a high content of Ruminococcaceae family (HR = 6.3, 95% CI: 2.6 to 15.3, p < 0.0001) and in patients with a low abundance of Clostridia UCG-014 (HR = 3.8, 95% CI: 1.5 to 9.8, p = 0.005) regardless of the immunotherapy line. Conclusions: The Clostridia class in gut microbiota could affect the effectiveness of immunotherapy, as well as the length of survival of NSCLC patients who received this method of treatment.
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Bacteria of the Bacillus cereus group are Gram-positive rods and are widespread in nature, but little information is currently available about their presence in reptiles. Here, we report draft genome sequences of six Bacillus isolates belonging to three species, namely, Bacillus cereus, Bacillus paranthracis, and Bacillus toyonensis, isolated from pet reptiles in Poland.
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The significance of Akkermansia bacteria presence in gut micobiome, mainly Akkermansia mucinifila, is currently being investigated in the context of supporting therapy and marker for response to immunotherapy in cancer patients. It is indicated that patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs) respond better to treatment if this bacterium is present in the intestine.We performed next-generation sequencing of the gut microbiome from patients treated in the first or second line therapy with anti-PD-1 (anti-programmed death 1) or anti-PD-L1 (anti-programmed death ligand 1) monoclonal antibodies. In our study group of 47 NSCLC patients, the percentage of Akkermansiaceae was higher in patients with disease stabilization and with partial response to immunotherapy compared to patients with disease progression. Moreover, we found that a higher percentage of Akkermansiaceae was present in patients with squamous cell carcinoma compared to adenocarcinoma. Our study showed that Akkermansiaceae could be supporting marker for response to immunotherapies in NSCLC patients, nonetheless further in-depth studies should be conducted in the role of Akkermansiaceae in cancer immunotherapy.
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OBJECTIVES: This study was initiated to collect retrospective information on the occurrence of plasmid-mediated quinolone resistance (PMQR) in Salmonella enterica and Escherichia coli isolates in Europe and to identify the responsible genes. METHODS: Databases of national reference laboratories containing MIC values for Salmonella and E. coli isolated between 1994 and 2009 in animals, humans, food and the environment from 13 European countries were screened for isolates exhibiting a defined quinolone resistance phenotype, i.e. reduced susceptibility to fluoroquinolones and nalidixic acid. PCR and sequence analysis were performed to identify the responsible PMQR genes. RESULTS: Screening of databases of 13 European countries resulted in a selection of 1215 Salmonella and 333 E. coli isolates. PMQR genes were identified in 59% of the Salmonella isolates and 15% of the E. coli isolates selected. In Salmonella, qnrS1 (nâ=â125) and variants of qnrB (nâ=â138) were frequently identified, whereas qnrA1 (nâ=â3) and aac(6')-1b-cr (nâ=â3) were rarely found. qnrD was detected in 22 Salmonella isolates obtained from humans and animals. In E. coli, qnrS1 was identified in 19 isolates and qnrB19 was found in one isolate. No qnrC or qepA genes were detected in either Salmonella or E. coli. CONCLUSIONS: This study shows the occurrence and dissemination of PMQR genes in Salmonella and E. coli in Europe with a defined quinolone resistance phenotype. We also report the first detection of qnrD in Salmonella collected in Europe.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Quinolonas/farmacologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , DNA Bacteriano/química , DNA Bacteriano/genética , Microbiologia Ambiental , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Europa (Continente) , Microbiologia de Alimentos , Genes Bacterianos , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Infecções por Salmonella/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/isolamento & purificação , Análise de Sequência de DNARESUMO
There has been an increase in the number of reports on Salmonella enterica subsp. enterica serovar Infantis (S. Infantis) isolated from animals and humans. Recent studies using whole genome sequencing (WGS) have provided evidence on the likely contribution of a unique conjugative megaplasmid (pESI; ~280 kb) to the dissemination of this serovar worldwide. In the present study, twenty-two unrelated Salmonella strains [S. Infantis (n = 20) and Salmonella 6,7:r:- (n = 2)] and their plasmids were investigated using next generation sequencing technologies (MiSeq and MinION) to unravel the significant expansion of this bacteria in Turkey. Multi-locus sequence typing, plasmid replicons, resistance gene contents as well as phylogenetic relations between strains were determined. According to the WGS data, all S. Infantis possessed the relevant megaplasmid backbone genes and belonged to sequence type 32 (ST32) with the exception of a single novel ST7091. Tetracycline and trimethoprim/sulfamethoxazole resistance were found to be widespread in S. Infantis strains and the resistant strains exclusively carried the tetA, sul1, sul2 and dfrA14 genes. One S. Infantis isolate was also a carrier of the plasmid-mediated ampC via blaCMY-2, gene. Moreover, full genomes of four S. Infantis isolates were reconstructed based on hybrid assembly. All four strains contained large plasmids (240-290 kb) similar to previously published megaplasmid (pESI) and accompanied by several small plasmids. The megaplasmid backbone contained a toxin-antitoxin system, two virulence cassettes and segments associated with heavy metals resistance, while variable regions possessed several antibiotic resistance genes flanked by mobile elements. This study indicated that pESI-like megaplasmid is widely disseminated within the tested S. Infantis strains of chicken meat, warranting further genomic studies on clinical strains from humans and animals to uncover the overall emergence and spread of this serovar.