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In this work, we synthesized an hexasaccharide derived from the capsular polysaccharide of group B Streptococcus type III capsular polysaccharide. Our convergent 3 + 3 strategy avoided the use of benzyl protecting groups allowing the installation of an azide anchoring group and providing a high yield for the final deprotection steps. Moreover, the minimal hexasaccharidic epitope was conjugated to CRM197 and BSA via copper-catalyzed azide-alkyne cycloaddition for the preparation of a semisynthetic carbohydrate-based vaccine.
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Antimicrobial resistance (AMR) is one of the greatest threats to global health worldwide and is threatening not only humans, but also animal production systems, including dairy farms. The objective of this paper was to describe risks factors associated with AMR on dairy farms in Québec, Canada. This observational cross-sectional study included 101 commercial dairy farms and took place between the springs of 2017 and 2018 for a one-year period. We explored risk factors such as farm practices and producer's knowledge (measured using a questionnaire), antimicrobial use (quantified using veterinary invoices), and the presence of Salmonella Dublin (tested by serology). We evaluated AMR with fecal Escherichia coli retrieved from pre-weaned calves and lactating cows using the following outcomes: the presence of extended-spectrum-ß-lactamase/AmpC resistance and the number of resistances to antimicrobial classes. We used logistic regression models to evaluate the association between each risk factor and the 2 outcomes for the 2 types of samples (pre-weaned calves and lactating cows). Furthermore, we explored the relationships between these risk factors utilizing data dimensionality reduction and hierarchical clustering. Outputs of these analyses were used as regressors for AMR in regression models. While the results for univariate analyses were ambiguous, the unsupervised analysis naturally categorized the sample of farms according to their health/treatment status (dimension 1, explaining 12.9% of the variance) and herd size (dimension 2, explaining 7.8%). Three clusters of farms were identified (cluster 1: mainly healthy herds and low ceftiofur users, cluster 2: relatively high ceftiofur users, cluster 3: farms with a higher incidence of diseases and higher antimicrobial treatment rates). Dimension 1 and cluster membership were statistically associated with the presence of extended-spectrum-ß-lactamase/AmpC resistance in lactating cows and in pre-weaned calves. Dimension 1 was also statistically associated with the number of resistances in lactating cows and in pre-weaned calves. This study highlights the complexity of analyzing risk factors associated with AMR. Our results suggest that the herd health status and the AMU-related practices used are associated with AMR in dairy farms. However, prospective studies are needed to confirm a causal relation.
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The global food animal industry faces a growing concern regarding antimicrobial resistance (AMR), primarily driven by the use of antimicrobials (AM) for the treatment, control, and prevention of diseases. Addressing this challenge requires promoting responsible antimicrobial use (AMU) practices. In 2019, the province of Québec, Canada, took a significant step by implementing a regulation that limits the use of AM of very high importance for human medicine (category I AM as defined by Health Canada) in the food animal industry. However, the implementation of such regulation can significantly influence behavioral shifts among producers, contributing to the wider effort against AMR. Therefore, the objective of this observational study was to describe the perceived changes in dairy producers' knowledge and on-farm practices following the implementation of this regulation, using a cohort design. Data collection involved administering questionnaires to 87 dairy producers from 3 regions of the province of Québec (Estrie, Montérégie, Centre-Du-Québec) before (2017-2018) and after (2020-2021) the implementation of the regulation. The questionnaires explored the descriptive characteristics of farms, the knowledge of producers about the categorization of AM, the on-farm treatment practices, and the perceived effects of the regulation. Statistical analysis included t-tests and McNemar tests to compare the paired data obtained using the 2 questionnaires. The results indicated an increase in the knowledge score (the number of AM correctly categorized by the producers by their importance for human medicine) after the implementation of the regulation, suggesting an improved understanding of the categorization of AM based on their importance for human medicine. Trends in AMU practices for treating clinical mastitis and reproductive diseases suggested that category I AM were less likely to be reported as the primary treatment after the regulation, whereas category II AM were more often reported as primary treatment. Adoption of the selective dry cow therapy method significantly increased, whereas the use of teat sealants remained unchanged. Moreover, producers had divergent perceptions regarding the effect of the regulation on the cure rates and disease frequencies. This disparity emphasizes the need for comprehensive data collection to discern the risks associated with such regulatory shifts. The study acknowledges several limitations, including the potential for recall bias, confirmation bias, and desirability bias. Despite these limitations, this study shows that implementing regulations to encourage responsible AMU drives positive transformations in producers' knowledge and on-farm practices. This underscores the pivotal effect of proactive interventions in combating the escalating threat of AMR within the global food animal industry.
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Anti-Infecciosos , Indústria de Laticínios , Fazendeiros , Fazendas , Animais , Fazendeiros/psicologia , Quebeque , Bovinos , Anti-Infecciosos/uso terapêutico , Inquéritos e Questionários , Feminino , HumanosRESUMO
Many of the disease-causing toxins of the pathogenic bacterium Clostridium perfringens are harboured on large, highly stable, conjugative plasmids. Previous work has established the requirement of a ParMRC-like partitioning system for plasmid maintenance, but little is known about other mechanisms used to ensure stable plasmid inheritance. The archetypal 47â¯kb Tcp plasmid, pCW3, encodes a gene, resP, whose putative product has sequence similarity to members of the serine recombinase family of site-specific recombinases. ResP is therefore likely to function to resolve plasmid multimers. Sequence analysis identified that resP genes are present on all C. perfringens plasmid families, suggesting a conserved function in these plasmids. To assess the requirement of resP for the stability of pCW3, deletion mutants were constructed. Deletion of resP from pCW3 resulted in a marked instability phenotype that was rescued upon complementation with the wild-type resP gene. Complementation with resP genes from two different C. perfringens plasmids demonstrated that only closely related resP genes can complement the mutation on pCW3. The function of ResP in vivo was examined using an Escherichia coli model system, which determined that two directly repeated res sites were required for the resolution of DNA and that ResP could resolve multimeric plasmid forms into monomeric units. Based on these findings we concluded that ResP could catalyse the resolution of plasmid multimers and was required for the maintenance of Tcp plasmids within C. perfringens. Overall, the results of this study have significant implications for our understanding of the maintenance of toxin-encoding plasmids within C. perfringens.
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Infecções por Clostridium/genética , Clostridium perfringens/genética , Genes Bacterianos/genética , Plasmídeos/genética , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/microbiologia , Clostridium perfringens/efeitos dos fármacos , Clostridium perfringens/patogenicidade , Conjugação Genética/genética , DNA Bacteriano/genética , Humanos , Plasmídeos/efeitos dos fármacos , Tetraciclina/farmacologiaRESUMO
Klebsiella spp. are important opportunistic pathogens commonly defined as environmental clinical mastitis agents. Despite Klebsiella mastitis being clinically impairing in cows and costly to the industry, only a few studies describe Klebsiella isolated from mastitis cases. The aim of this work was to characterize species of Klebsiella involved in clinical mastitis cases in Canada. Klebsiella isolated from clinical mastitis cases (n = 53) were identified to the species level using a biochemical test panel and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The rpoB gene sequence was used as the gold standard method and identified Klebsiella pneumoniae (n = 40), Klebsiella oxytoca (n = 9), Raoultella ornithinolytica (n = 2), and Raoultella planticola (n = 2). Raoultella, a genus closely related to Klebsiella, was also accurately identified using mass spectrometry but not via biochemical testing. Using the disc diffusion technique, 31 (58%) isolates were found to be susceptible to all antimicrobials tested (n = 18). The remaining 22 (42%) isolates were resistant to 1 or more of the following antimicrobials: kanamycin (2%), streptomycin (38%), spectinomycin (13%), sulfisoxazole (13%), and tetracycline (19%). The following antimicrobial resistance genes were identified: tetA, tetB, sul1, strA/strB, and aadA. Random amplified polymorphic DNA revealed the majority of our isolates as unrelated and having different patterns, indicating environmental contamination as the primary source of infection. All isolates were shown to be biofilm producers. In conclusion, although antimicrobial resistance was low for both Klebsiella and Raoultella species, genetically related Klebsiella spp. isolates appeared to be more resistant.
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Klebsiella/isolamento & purificação , Mastite Bovina/microbiologia , Animais , Antibacterianos/farmacologia , Canadá , Bovinos , Farmacorresistência Bacteriana/genética , Feminino , Klebsiella/classificação , Klebsiella/efeitos dos fármacos , Klebsiella/fisiologia , Mastite Bovina/tratamento farmacológico , Testes de Sensibilidade MicrobianaRESUMO
Necrotic enteritis (NE) is a major problem in antibiotic-free (ABF) chicken flocks and specific strains of Clostridium perfringens are known to induce NE. The objective of this study was to develop a chicken intestinal ligated loop model in order to compare the virulence of various C. perfringens strains recovered from consecutive ABF flocks with and without NE. Intestinal loops were surgically prepared in 10 anaesthetized specific-pathogen-free chickens and alternately inoculated with C. perfringens isolates or brain heart infusion (BHI) media. Histological lesion scoring was performed for each loop. All strains from NE-affected flocks induced histological lesions compatible with NE whereas inoculation of loops with a commensal C. perfringens strain or BHI did not. Among inoculated strains, CP0994 (netB-positive and cpb2-positive) and CP-2003-1256 (netB-positive) demonstrated mean histological lesion scores significantly higher (P < 0.01) than those obtained with a commensal strain or BHI whereas strain CP1073 (netB-negative and cpb2-positive) induced intestinal lesions without significantly higher scores. In loops where villi were colonized by Gram-positive rods, significantly higher (P < 0.01) mean histological lesion scores were observed. This result supports the hypothesis that colonization of the intestinal mucosa by C. perfringens is a critical step in the pathogenesis of NE. Finally, we demonstrated the importance of controlling virulent C. perfringens strains in ABF chicken flocks as a highly virulent strain can be present in consecutive flocks with NE and possibly affect multiple flocks.
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Infecções por Clostridium/veterinária , Clostridium perfringens/patogenicidade , Enterite/veterinária , Necrose/veterinária , Doenças das Aves Domésticas/microbiologia , Animais , Toxinas Bacterianas/genética , Galinhas , Infecções por Clostridium/microbiologia , Infecções por Clostridium/patologia , Clostridium perfringens/genética , Clostridium perfringens/isolamento & purificação , Modelos Animais de Doenças , Enterite/microbiologia , Enterite/patologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Necrose/microbiologia , Doenças das Aves Domésticas/patologia , Organismos Livres de Patógenos Específicos , VirulênciaRESUMO
Clostridium perfringens is an opportunistic pathogen that can cause food poisoning in humans and various enterotoxemia in animal species. Recently, it was shown to form mono-species biofilms, a structured community of bacterial cells enclosed in a self-produced extracellular matrix. Biofilms have been associated with tolerance to antibiotics, disinfectants, and physical and environmental stresses. Very little is known about the tolerance of C. perfringens biofilm toward disinfectants. In the present study, susceptibilities of C. perfringens biofilms to five types of commonly used disinfectants on farms and in food processing environments were analysed. In this paper, we show that C. perfringens mono-species biofilms can protect the bacterial cells from the action of potassium monopersulfate, quaternary ammonium chloride, hydrogen peroxide and glutaraldehyde solutions. However, sodium hypochlorite solution was shown to be effective on C. perfringens biofilms. Our investigation of dual-species biofilms of C. perfringens with the addition of Staphylococcus aureus or Escherichia coli demonstrated that overall, the mono-species biofilm of C. perfringens was more tolerant to all disinfectants than the dual-species biofilms. For the anaerobic grown biofilms, the mono-species biofilm of C. perfringens was more tolerant to sodium hypochlorite and quaternary ammonium chloride than the dual-species biofilms of C. perfringens with S. aureus or E. coli. This study demonstrates that C. perfringens biofilm is an effective protection mechanism to disinfectants commonly used on farms and in food processing environments.
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Biofilmes/efeitos dos fármacos , Clostridium perfringens/efeitos dos fármacos , Clostridium perfringens/fisiologia , Desinfetantes/farmacologia , Anaerobiose , Clostridium perfringens/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Indústria Alimentícia/normas , Microbiologia de Alimentos , Indústria de Processamento de Alimentos/métodos , Compostos de Potássio/farmacologia , Hipoclorito de Sódio/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Sulfatos/farmacologiaRESUMO
Clostridium perfringens is an opportunistic pathogen that can cause food poisoning in humans and various enterotoxaemias in animal species. Recently, C. perfringens was shown to form biofilms, a structured community of bacterial cells enclosed in a self-produced extracellular matrix. However, very little is known on the subject and no information is available on gene expression in C. perfringens biofilms. To gain insights into the differences between free-living C. perfringens cells and those in biofilms, we used RNA sequencing. In total, 25.7% of genes showed differential expression in the two growth modes; about 12.8% of genes were up-regulated and about 12.9% were down-regulated in biofilms. We show that 772 genes were significantly differentially expressed between biofilms and planktonic cells from the supernatant of biofilms. Genes that were down-regulated in biofilm cells, relative to planktonic cells, included those involved in virulence, energy production, amino acid, nucleotide and carbohydrate metabolism, and in translation and ribosomal structure. Genes up-regulated in biofilm cells were mainly involved in amino acid and carbohydrate metabolism, transcription, inorganic ion metabolism and in defence mechanisms. This study provides new insights into the transcriptomic response of C. perfringens during biofilm formation.
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Biofilmes/crescimento & desenvolvimento , Infecções por Clostridium/microbiologia , Clostridium perfringens/genética , Regulação Bacteriana da Expressão Gênica , Transcriptoma , Animais , Proteínas de Bactérias/genética , Clostridium perfringens/crescimento & desenvolvimento , Regulação para Baixo , Perfilação da Expressão Gênica , Humanos , Plâncton/microbiologia , Análise de Sequência de RNA , Regulação para Cima , VirulênciaRESUMO
This prospective clinical study evaluates the effectiveness of an alcohol-based hand rub (Avagard™) for pre-surgical hand antisepsis in an equine hospital and compares it with traditional scrubbing technique using 4% chlorhexidine gluconate sponges and water. Prior to elective surgery, 3 board-certified surgeons were randomly assigned to hand antisepsis with either technique. Culture samples of each hand were taken at 4 times: before and after neutral soap hand wash, after scrub or rubbing technique, and after surgery. There was no significant difference in mean bacterial colony forming units between scrub and rub techniques over the 3 time periods (P = 0.6), controlling for initial counts. One horse from the scrub group had a skin incision infection following stifle arthroscopy; this was resolved with medical treatment. The alcohol-based hand rub is equivalent in efficacy for pre-surgical hand antisepsis to traditional water-based scrubs in an equine hospital setting.
Comparaison de l'alcool à friction et d'une technique de brossage au gluconate de chlorhexidine à base d'eau pour l'antisepsie des mains avant les chirurgies non urgentes chez les chevaux. Cette étude clinique prospective évalue l'efficacité d'un alcool à friction (AvagardMD) pour l'antisepsie des mains préalable à une chirurgie dans un hôpital équin et elle la compare à la technique de brossage traditionnelle au moyen d'éponges de gluconate de chlorhexidine 4 % et d'eau. Avant une chirurgie non urgente, trois chirurgiens agréés ont été assignés au hasard à l'antisepsie des mains avec l'une ou l'autre technique. Des échantillons de chaque main ont été prélevés quatre fois pour culture : avant et après le lavage des mains avec un savon neutre, après la technique de brossage et de friction et après la chirurgie. Il n'y avait aucune différence significative dans les moyennes des dénombrements bactériens d'unités formatrices de colonies entre les techniques de brossage et de friction pendant les trois périodes de temps (P = 0,6), en tenant compte des témoins pour les dénombrements initiaux. Un cheval du groupe de brossage a développé une infection au site de l'incision après une arthroscopie du grasset qui a été résolue par traitement médical. La friction des mains à l'alcool est équivalente, en matière d'efficacité pour l'antisepsie des mains avant la chirurgie, au brossage traditionnel à l'eau dans un milieu hospitalier équin.(Traduit par Isabelle Vallières).
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Antissepsia/métodos , Bactérias/efeitos dos fármacos , Clorexidina/análogos & derivados , Etanol/farmacologia , Desinfecção das Mãos , Mãos/microbiologia , Doenças dos Cavalos/microbiologia , Infecção da Ferida Cirúrgica/veterinária , Animais , Bactérias/isolamento & purificação , Clorexidina/farmacologia , Contagem de Colônia Microbiana , Doenças dos Cavalos/prevenção & controle , Cavalos , Humanos , Período Pré-Operatório , Infecção da Ferida Cirúrgica/prevenção & controleAssuntos
Anti-Infecciosos , Doenças dos Bovinos , Animais , Bovinos , Indústria de Laticínios , QuebequeAssuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Animais , Argentina/epidemiologia , Bovinos , Feminino , Mastite Bovina/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificaçãoRESUMO
Diverse fecal and nonfecal bacterial contamination and nutrient sources (e.g. agriculture, human activities and wildlife) represent a considerable non-point source load entering natural recreational waters which may adversely affect water quality. Monitoring of natural recreational water microbial quality is most often based mainly on testing a set of microbiological indicators. The cost and labour involved in testing numerous water samples may be significant when a large number of sites must be monitored repetitively over time. In addition to water testing, ongoing monitoring of key environmental factors known to influence microbial contamination may be carried out as an additional component. Monitoring of environmental factors can now be performed using remote sensing technology which represents an increasingly recognized source of rigorous and recurrent data, especially when monitoring over a large or difficult to access territory is needed. To determine whether this technology could be useful in the context of recreational water monitoring, we evaluated a set of agroenvironmental determinants associated with fecal contamination of recreational waters through a multivariable logistic regression model built with data extracted from satellite imagery. We found that variables describing the proportions of land with agricultural and impervious surfaces, as derived from remote sensing observations, were statistically associated (odds ratio, OR = 11 and 5.2, respectively) with a higher level of fecal coliforms in lake waters in the southwestern region of Quebec, Canada. From a technical perspective, remote sensing may provide important added-value in the monitoring of microbial risk from recreational waters and further applications of this technology should be investigated to support public health risk assessments and environmental monitoring programs relating to water quality.
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Praias/normas , Monitoramento Ambiental/métodos , Água Doce/análise , Tecnologia de Sensoriamento Remoto , Qualidade da Água , Fezes , Modelos Logísticos , QuebequeRESUMO
Among the many global health issues, antimicrobial resistance (AMR) is one that exemplifies the One Health approach, defined as a joint effort in which multiple disciplines collaborate to provide solutions for human, animal, and environmental health [...].
RESUMO
With the emergence of antimicrobial resistance (AMR), many countries are implementing restrictive regulations to reduce antimicrobial use (AMU) in animal production. Although these measures are effective at the national level, their implementation may generate challenges for producers and veterinarians. The objective of this study was to explore the barriers and facilitators of implementing a new regulation restricting the use of antimicrobials of very high importance for human health in the dairy production sector in the province of Québec, Canada. Individual interviews were conducted with fifteen veterinarians and twenty-seven dairy producers. Thematic analysis was performed based on the COM-B model of behavior change (capability-opportunity-motivation-behavior). Our results indicated that the lack of availability of alternative treatments, the long delays related to diagnostic tests and the fear of economic consequences were major barriers to the implementation of the regulation. A small number of producers also perceived that the regulation negatively impacted the health and wellbeing of their animals. Additionally, participants acknowledged the importance of early education and training to better understand the purpose of the regulation and increase its acceptability. Lastly, most participants reported that they had not only reduced their use of antimicrobials of very high importance for human health following the regulation, but they had also increased preventive practices on their farm. This study reveals that the implementation of restrictive regulations to reduce AMU in animal production can lead to multiple challenges in practice. Our results highlight the need for better communication and training of producers and veterinarians before and during the implementation of similar regulations in the future and underline the importance of measuring the direct and indirect impacts of those regulations on productivity and on animal health and wellbeing.
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Despite its importance in veterinary medicine, there is little information about antimicrobial resistance (AMR) and its transmission in dairy cattle. The aim of this work is to compare AMR phenotypes and genotypes in resistant Escherichia coli and to determine how the resistance genes spread among the E. coli population on dairy farms in Québec, Canada. From an existing culture collection of E. coli isolated from dairy manure, a convenient selection of the most resistant isolates (a high level of multidrug resistance or resistance to broad-spectrum ß-lactams or fluoroquinolones) was analyzed (n = 118). An AMR phenotype profile was obtained for each isolate. Whole genome sequencing was used to determine the presence of resistance genes, point mutations, and mobile genetic elements. In addition, a subset of isolates from 86 farms was taken to investigate the phylogenetic relationship and geographic distribution of the isolates. The average agreement between AMR phenotypes and genotypes was 95%. A third-generation cephalosporin resistance gene (blaCTX-M-15), a resistance gene conferring reduced susceptibility to fluoroquinolones (qnrS1), and an insertion sequence (ISKpn19) were detected in the vicinity of each other on the genome. These genes were harbored in one triplet of clonal isolates from three farms located >100 km apart. Our study reveals the dissemination of resistant E. coli clones between dairy farms. Furthermore, these clones are resistant to broad-spectrum ß-lactam and fluoroquinolone antimicrobials.
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Antimicrobial resistance can be effectively limited by improving the judicious use of antimicrobials in food production. However, its effect on the spread of AMR genes in animal populations is not well described. In the province of Québec, Canada, a new legislation implemented in 2019 has led to an unprecedented reduction in the use of critical antimicrobials in dairy production. We aimed to investigate the potential link between ESBL/AmpC E. coli isolated before and after legislation and to determine the presence of plasmids carrying genes responsible for critical AMR. We collected fecal samples from calves, cows, and manure pit from 87 Québec dairy farms approximately 2 years before and 2 years after the legislation came into effect. The whole genomes of 183 presumptive ESBL/AmpC E. coli isolated after cefotaxime enrichment were sequenced. Their phylogenetic characteristics (MLST, serogroup, cgMLST) and the presence of virulence and resistance genes and replicons were examined. A maximum likelihood phylogenetic tree was constructed based on single nucleotide polymorphism (SNPs). We identified 10 clonal lineages (same cgMLST) and 7 clones (SNPs ≤ 52). Isolates belonging to these clones could be found on different farms before and after the legislation, strongly suggesting a clonal spread of AMR genes in the population during this 4-year period. All isolates were multidrug resistant (MDR), with clone 2 being notable for the presence of macrolide, fluoroquinolone, and third-generation cephalosporin resistance genes. We also identified clinically relevant ExPEC (ST10) and APEC-like lineages (ST117, ST58, ST88) associated with the presence of ExPEC and APEC virulence genes, respectively. Our data also suggests the presence of one epidemic plasmid belonging to the IncY incompatibility group and carrying qnrs1 and blaCTX-M-15. We demonstrated that AMR genes spread through farms and can persist over a 4-year period in the dairy cattle population through both plasmids and E. coli clones, despite the restriction of critical antimicrobial use. MDR ExPEC and APEC-like STs are present in the normal microbiota of cattle (more frequently in calves). These data increase our knowledge on gene dissemination dynamics and highlight the fact that biosecurity measures should be enhanced in this industry to limit such dissemination.
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The recently described phenol-soluble modulin PSM-mec was detected in Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus fleuretti, Staphylococcus hominis, Staphylococcus pseudintermedius, Staphylococcus saprophyticus, Staphylococcus simulans and Staphylococcus vitulinus from different hosts (humans, goats, dogs, cats, pigs, cattle and turkeys). It was identified in isolates harbouring SCCmec types II, IIA, IIB, IID, III, VIII and in some irregular or truncated elements.
Assuntos
Proteínas de Bactérias/genética , Staphylococcus/genética , Fatores de Virulência/genética , Animais , Genótipo , Humanos , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Antimicrobial resistance (AMR) represents a global threat to both human and animal health and has received increasing attention over the years from different stakeholders. Certain AMR bacteria circulate between humans, animals, and the environment, while AMR genes can be found in all ecosystems. The aim of the present review was to provide an overview of antimicrobial use in food-producing animals and to document the current status of the role of farm animals in the spread of AMR to humans. The available body of scientific evidence supported the notion that restricted use of antimicrobials in farm animals was effective in reducing AMR in livestock and, in some cases, in humans. However, most recent studies have reported that livestock have little contribution to the acquisition of AMR bacteria and/or AMR genes by humans. Overall, strategies applied on farms that target the reduction of all antimicrobials are recommended, as these are apparently associated with notable reduction in AMR (avoiding co-resistance between antimicrobials). The interconnection between human and animal health as well as the environment requires the acceleration of the implementation of the 'One Health' approach to effectively fight AMR while preserving the effectiveness of antimicrobials.
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To tackle antimicrobial resistance (AMR), one of the major health threats of this century, the World Health Organization (WHO) endorsed a global action plan in 2015. This plan calls countries to develop national actions to address AMR. The province of Québec, Canada, adopted a new regulation on the 25th of February 2019, to limit the use in food animals of antimicrobials of very high importance in human medicine. We aimed to establish the impact of this regulation by comparing the AMR situation in dairy cattle in Québec ~2 years before and 2 years after its introduction. We sampled calves, cows, and the manure pit in 87 farms. Generic and putative ESBL/AmpC E. coli were tested for susceptibility to 20 antimicrobials. Logistic regression was used to investigate whether the probability of antimicrobial resistance differed between isolates obtained from the pre and post regulation periods by sample type (calves, cows, manure pit) and in general. To identify AMR genes dissemination mechanisms, we sequenced the whole genome of 15 generic isolates. In the generic collection, at the herd level, the proportion of multidrug resistant (MDR) isolates, decreased significantly from 83 to 71% (p = 0.05). Folate inhibitor and aminoglycoside resistances demonstrated a significant decrease. However, when analyzed by sample type (calves, cows, manure pit), we did not observe a significant AMR decrease in any of these categories. In the ESBL/AmpC collection, we did not detect any significant difference between the two periods. Also, the general resistance gene profile was similar pre and post regulation. We identified both clonal and plasmidic dissemination of resistance genes. In conclusion, as early as 2 years post regulation implementation, we observed a significant decrease in MDR in the dairy industry in Quebec in the generic E. coli collection with folate inhibitor and aminoglycoside resistances showing the most significant decrease. No other significant decreases were yet observed.
RESUMO
The objective of the study was to compare three quantification methods to a "garbage can audit" (reference method, REF) for monitoring antimicrobial usage (AMU) from products other than medicated feed over one year in 101 Québec dairy farms. Data were collected from veterinary invoices (VET method), from the "Amélioration de la Santé Animale au Québec" provincial program (GOV method), and from farm treatment records (FARM method). The AMU rate was reported in a number of Canadian Defined Course Doses for cattle (DCDbovCA) per 100 cow-years. Electronic veterinary sales data were obtained for all farms for VET and GOV methods. For the FARM method, a herd management software was used by 68% of producers whereas farm treatment records were handwritten for the others; records could not be retrieved in 4% of farms. Overall, agreement was almost perfect between REF and VET methods (concordance correlation coefficient (CCC) = 0.83), but moderate between REF and GOV (CCC = 0.44), and between REF and FARM (CCC = 0.51). Only a fair or slight agreement was obtained between any alternative method of quantification and REF for oral and intrauterine routes. The billing software used by most of Québec's dairy veterinary practitioners seems promising in terms of surveillance and benchmarking of AMU in the province.