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1.
Mol Microbiol ; 117(4): 770-789, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34942035

RESUMEN

Salmonella is a major foodborne pathogen and is responsible for a range of diseases. Not all Salmonella contributes to severe health outcomes as there is a large degree of genetic heterogeneity among the 2,600 serovars within the genus. This variability across Salmonella serovars is linked to numerous genetic elements that dictate virulence. While several genetic elements encode virulence factors with well-documented contributions to pathogenesis, many genetic elements implicated in Salmonella virulence remain uncharacterized. Many pathogens encode a family of E3 ubiquitin ligases that are delivered into the cells that they infect using a Type 3 Secretion System (T3SS). These effectors, known as NEL-domain E3s, were first characterized in Salmonella. Most Salmonella encodes the NEL-effectors sspH2 and slrP, whereas only a subset of Salmonella encodes sspH1. SspH1 has been shown to ubiquitinate the mammalian protein kinase PKN1, which has been reported to negatively regulate the pro-survival program Akt. We discovered that SspH1 mediates the degradation of PKN1 during infection of a macrophage cell line but that this degradation does not impact Akt signaling. Genomic analysis of a large collection of Salmonella genomes identified a putative new gene, sspH3, with homology to sspH1. SspH3 is a novel NEL-domain effector.


Asunto(s)
Proteínas Bacterianas , Proteínas Proto-Oncogénicas c-akt , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Mamíferos/metabolismo , Salmonella/genética , Salmonella/metabolismo , Sistemas de Secreción Tipo III , Ubiquitina-Proteína Ligasas/metabolismo
2.
Food Microbiol ; 101: 103877, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34579845

RESUMEN

Salmonella enterica subsp. enterica is one of the leading causes of human foodborne infections and several outbreaks are now associated with the consumption of fresh fruit and vegetables. This study aims at evaluating whether Salmonella virulence can be linked to an enhanced ability to survive successive digestive environments. Thirteen S. enterica strains were selected according to high and low virulence phenotypes. Lettuce inoculated separately with each S. enterica strain was used as food matrix in the TNO gastrointestinal model (TIM-1) of the human upper gastrointestinal tract. During the passage in the stomach, counts determined using PMA-qPCR were 2-5 logs higher than the cultivable counts for all strains indicating the presence of viable but non-cultivable cells. Bacterial growth was observed in the duodenum compartment after 180 min for all but one strain and growth continued into the ileal compartment. After passage through the simulated gastrointestinal tract, both virulent and avirulent S. enterica strains survived but high virulence strains had a significantly (p = 0.004) better average survival rate (1003 %-3753 %) than low virulence strains (from 25 % to 3730%). The survival rates of S. enterica strains could be linked to the presence of genes associated with acid and bile resistance and their predicted products. The presence of single nucleotide polymorphisms may also impact the function of virulence associated genes and play a role in the resulting phenotype. These data provide an understanding of the relationship between measured virulence potential and survival of S. enterica during dynamic simulated gastrointestinal transit.


Asunto(s)
Tracto Gastrointestinal/microbiología , Salmonella/patogenicidad , Virulencia , Humanos , Modelos Biológicos
3.
Food Microbiol ; 95: 103709, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33397626

RESUMEN

The ongoing pandemic involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised the question whether this virus, which is known to be spread primarily though respiratory droplets, could be spread through the fecal-oral route or via contaminated food. In this article, we present a critical review of the literature exploring the potential foodborne transmission of several respiratory viruses including human coronaviruses, avian influenza virus (AVI), parainfluenza viruses, human respiratory syncytial virus, adenoviruses, rhinoviruses, and Nipah virus. Multiple lines of evidence, including documented expression of receptor proteins on gastrointestinal epithelial cells, in vivo viral replication in gastrointestinal epithelial cell lines, extended fecal shedding of respiratory viruses, and the ability to remain infectious in food environments for extended periods of time raises the theoretical ability of some human respiratory viruses, particularly human coronaviruses and AVI, to spread via food. However, to date, neither epidemiological data nor case reports of clear foodborne transmission of either viruses exist. Thus, foodborne transmission of human respiratory viruses remains only a theoretical possibility.


Asunto(s)
Enfermedades Transmitidas por los Alimentos/virología , Infecciones del Sistema Respiratorio/transmisión , Infecciones del Sistema Respiratorio/virología , Animales , Aves , COVID-19/transmisión , COVID-19/virología , Heces/virología , Humanos , SARS-CoV-2/aislamiento & purificación
4.
BMC Genomics ; 21(1): 374, 2020 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-32456612

RESUMEN

BACKGROUND: Bacteriophages are bacterial parasites and are considered the most abundant and diverse biological entities on the planet. Previously we identified 154 prophages from 151 serovars of Salmonella enterica subsp. enterica. A detailed analysis of Salmonella prophage genomics is required given the influence of phages on their bacterial hosts and should provide a broader understanding of Salmonella biology and virulence and contribute to the practical applications of phages as vectors and antibacterial agents. RESULTS: Here we provide a comparative analysis of the full genome sequences of 142 prophages of Salmonella enterica subsp. enterica which is the full complement of the prophages that could be retrieved from public databases. We discovered extensive variation in genome sizes (ranging from 6.4 to 358.7 kb) and guanine plus cytosine (GC) content (ranging from 35.5 to 65.4%) and observed a linear correlation between the genome size and the number of open reading frames (ORFs). We used three approaches to compare the phage genomes. The NUCmer/MUMmer genome alignment tool was used to evaluate linkages and correlations based on nucleotide identity between genomes. Multiple sequence alignment was performed to calculate genome average nucleotide identity using the Kalgin program. Finally, genome synteny was explored using dot plot analysis. We found that 90 phage genome sequences grouped into 17 distinct clusters while the remaining 52 genomes showed no close relationships with the other phage genomes and are identified as singletons. We generated genome maps using nucleotide and amino acid sequences which allowed protein-coding genes to be sorted into phamilies (phams) using the Phamerator software. Out of 5796 total assigned phamilies, one phamily was observed to be dominant and was found in 49 prophages, or 34.5% of the 142 phages in our collection. A majority of the phamilies, 4330 out of 5796 (74.7%), occurred in just one prophage underscoring the high degree of diversity among Salmonella bacteriophages. CONCLUSIONS: Based on nucleotide and amino acid sequences, a high diversity was found among Salmonella bacteriophages which validate the use of prophage sequence analysis as a highly discriminatory subtyping tool for Salmonella. Thorough understanding of the conservation and variation of prophage genomic characteristics will facilitate their rational design and use as tools for bacterial strain construction, vector development and as anti-bacterial agents.


Asunto(s)
Bacteriófagos/genética , Bacteriófagos/fisiología , Genómica , Salmonella enterica/virología , Biodiversidad , Evolución Molecular , Genoma Viral/genética , Nucleótidos/genética , Sistemas de Lectura Abierta/genética
5.
BMC Genomics ; 21(1): 377, 2020 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-32471418

RESUMEN

BACKGROUND: Salmonella enterica is a leading cause of foodborne illness worldwide resulting in considerable public health and economic costs. Testing for the presence of this pathogen in food is often hampered by the presence of background microflora that may present as Salmonella (false positives). False positive isolates belonging to the genus Citrobacter can be difficult to distinguish from Salmonella due to similarities in their genetics, cell surface antigens, and other phenotypes. In order to understand the genetic basis of these similarities, a comparative genomic approach was used to define the pan-, core, accessory, and unique coding sequences of a representative population of Salmonella and Citrobacter strains. RESULTS: Analysis of the genomic content of 58 S. enterica strains and 37 Citrobacter strains revealed the presence of 31,130 and 1540 coding sequences within the pan- and core genome of this population. Amino acid sequences unique to either Salmonella (n = 1112) or Citrobacter (n = 195) were identified and revealed potential niche-specific adaptations. Phylogenetic network analysis of the protein families encoded by the pan-genome indicated that genetic exchange between Salmonella and Citrobacter may have led to the acquisition of similar traits and also diversification within the genera. CONCLUSIONS: Core genome analysis suggests that the Salmonella enterica and Citrobacter populations investigated here share a common evolutionary history. Comparative analysis of the core and pan-genomes was able to define the genetic features that distinguish Salmonella from Citrobacter and highlight niche specific adaptations.


Asunto(s)
Citrobacter/clasificación , Citrobacter/genética , Genómica , Filogenia , Salmonella enterica/clasificación , Salmonella enterica/genética , Genoma Bacteriano/genética
6.
Environ Microbiol ; 22(7): 2907-2920, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32363677

RESUMEN

In livestock production, antibiotics are used to promote animal growth, control infections and thereby increase profitability. This practice has led to the emergence of multiresistant bacteria such as Salmonella, of which some serovars are disseminated in the environment. The objective of this study is to evaluate microcin J25 as an inhibitor of Salmonella enterica serovars of various origins including human, livestock and food. Among the 116 isolates tested, 37 (31.8%) were found resistant to at least one antibiotic, and 28 were multiresistant with 19 expressing the penta-resistant phenotype ACSSuT. Microcin J25 inhibited all isolates, with minimal inhibitory concentration values ranging from 0.06 µg/ml (28.4 nM) to 400 µg/ml (189 µM). Interestingly, no cross-resistance was found between microcin J25 and antibiotics. Multiple sequence alignments of genes encoding for the different proteins involved in the recognition and transport of microcin J25 showed that only ferric-hydroxamate uptake is an essential determinant for susceptibility of S. enterica to microcin J25. Examination of Salmonella strains exposed to microcin J25 by transmission electronic microscopy showed for the first-time involvement of a pore formation mechanism. Microcin J25 was a strong inhibitor of several multiresistant isolates of Salmonella and may have a great potential as an alternative to antibiotics.


Asunto(s)
Bacteriocinas/farmacología , Salmonella enterica/genética , Animales , Antibacterianos/farmacología , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Fenómica , Salmonella enterica/efectos de los fármacos , Salmonella enterica/ultraestructura
7.
8.
Int J Mol Sci ; 21(5)2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-32164202

RESUMEN

Bacteriophages have shown promise as therapeutic alternatives to antibiotics for the control of infectious bacteria, including the human pathogen Salmonella. However, the development of effective phage-based applications requires the elucidation of key interactions between phages and target hosts, particularly since host resistance to phage is inevitable. Little is known about the alteration of host phenotypes following the development of resistance to phage. The aim of this study is to evaluate the antibiotic susceptibility and virulence of a Salmonella isolate following the development of resistance to bacteriophage SI1. We observed enhanced susceptibility to tetracycline and decreased invasion capacity in a differentiated Caco-2 intestinal cell line. Whole genome sequence analysis revealed an array of mutations, most notably, truncations in vgrG1_2, a core gene involved in Type VI secretion and mutations in the lipopolysaccharide, thereby indicating the plausible attachment site of phage SI1. These findings shed light on understanding the underlying mechanism for phage immunity within the host. Importantly, we reveal an associated genetic cost to the bacterial host with developing resistance to phages. Taken together, these results will aid in advancing strategies to delay or eliminate the development of host resistance when designing informed phage-based antimicrobials.


Asunto(s)
Proteínas Bacterianas/genética , Bacteriófagos/fisiología , Intestinos/citología , Salmonella enterica/patogenicidad , Tetraciclinas/farmacología , Bacteriófagos/genética , Células CACO-2 , Diferenciación Celular , Aptitud Genética , Humanos , Intestinos/efectos de los fármacos , Intestinos/microbiología , Lipopolisacáridos/genética , Pruebas de Sensibilidad Microbiana , Mutación , Salmonella enterica/genética , Salmonella enterica/virología , Acoplamiento Viral , Secuenciación Completa del Genoma
9.
Food Microbiol ; 73: 99-110, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29526232

RESUMEN

Salmonella enterica serovar Heidelberg (S. Heidelberg) is one of the top serovars causing human salmonellosis. This serovar ranks second and third among serovars that cause human infections in Québec and Canada, respectively, and has been associated with severe infections. Traditional typing methods such as PFGE do not display adequate discrimination required to resolve outbreak investigations due to the low level of genetic diversity of isolates belonging to this serovar. This study evaluates the ability of four whole genome sequence (WGS)-based typing methods to differentiate among 145 S. Heidelberg strains involved in four distinct outbreak events and sporadic cases of salmonellosis that occurred in Québec between 2007 and 2016. Isolates from all outbreaks were indistinguishable by PFGE. The core genome single nucleotide variant (SNV), core genome multilocus sequence typing (MLST) and whole genome MLST approaches were highly discriminatory and separated outbreak strains into four distinct phylogenetic clusters that were concordant with the epidemiological data. The clustered regularly interspaced short palindromic repeats (CRISPR) typing method was less discriminatory. However, CRISPR typing may be used as a secondary method to differentiate isolates of S. Heidelberg that are genetically similar but epidemiologically unrelated to outbreak events. WGS-based typing methods provide a highly discriminatory alternative to PFGE for the laboratory investigation of foodborne outbreaks.


Asunto(s)
Tipificación de Secuencias Multilocus/métodos , Intoxicación Alimentaria por Salmonella/microbiología , Infecciones por Salmonella/microbiología , Salmonella enterica/aislamiento & purificación , Secuenciación Completa del Genoma/métodos , Técnicas de Tipificación Bacteriana/métodos , Genoma Bacteriano , Humanos , Filogenia , Quebec/epidemiología , Intoxicación Alimentaria por Salmonella/epidemiología , Infecciones por Salmonella/epidemiología , Salmonella enterica/clasificación , Salmonella enterica/genética
10.
Appl Environ Microbiol ; 80(21): 6819-27, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25172861

RESUMEN

Identification of Salmonella serotypes is important for understanding the environmental diversity of the genus Salmonella. This study evaluates the diversity of Salmonella isolates recovered from 165 of 202 Central Florida surface water samples and investigates whether the serotype of the environmental Salmonella isolates can be predicted by a previously published multiplex PCR assay (S. Kim, J. G. Frye, J. Hu, P. J. Fedorka-Cray, R. Gautom, and D. S. Boyle, J. Clin. Microbiol. 44:3608-3615, 2006, http://dx.doi.org/10.1128/JCM.00701-06). Multiplex PCR was performed on 562 Salmonella isolates (as many as 36 isolates per water sample) to predict serotypes. Kauffmann-White serogrouping was used to confirm multiplex PCR pattern groupings before isolates were serotyped, analyzed by pulsed-field gel electrophoresis, and assayed for antimicrobial susceptibility. In 41.2% of the Salmonella-positive water samples, all Salmonella isolates had identical multiplex PCR patterns; in the remaining 58.8%, two or more multiplex PCR patterns were identified. Within each sample, isolates with matching multiplex PCR patterns had matching serogroups. The multiplex patterns of 495 isolates (88.1%) did not match any previously reported pattern. The remaining 68 isolates matched reported patterns but did not match the serotypes for those patterns. The use of the multiplex PCR allowed the number of isolates requiring further analysis to be reduced to 223. Thirty-three Salmonella enterica serotypes were identified; the most frequent included serotypes Muenchen, Rubislaw, Anatum, Gaminara, and IV_50:z4,z23:-. A majority (141/223) of Salmonella isolates clustered into one genotypic group. Salmonella isolates in Central Florida surface waters are serotypically, genotypically, and phenotypically (in terms of antimicrobial susceptibility) diverse. While isolates could be grouped as different or potentially the same using multiplex PCR, the multiplex PCR pattern did not predict the Salmonella serotype.


Asunto(s)
Salmonella enterica/clasificación , Salmonella enterica/aislamiento & purificación , Microbiología del Agua , Análisis por Conglomerados , Electroforesis en Gel de Campo Pulsado , Florida , Variación Genética , Genotipo , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Reacción en Cadena de la Polimerasa Multiplex , Fenotipo , Serogrupo
11.
J Food Prot ; 87(5): 100269, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38519033

RESUMEN

Cronobacter sakazakii can cause severe illnesses in infants, predominantly in preterm newborns, with consumption of contaminated powdered infant formula (PIF) being the major vehicle of infection. Using a dynamic human gastrointestinal simulator called the SHIME, this study examined the effects of gastric acidity and gastric digestion time of newborns on the survival and expression of stress genes of C. sakazakii. Individual strains, inoculated at 7 log CFU/mL into reconstituted PIF, were exposed to gastric pH values of 4.00, 5.00 and 6.00 for 4 h with gradual acidification. The survival results showed that C. sakazakii grew in the stomach portion of the SHIME during a 4-h exposure to pH 4.00, 5.00 and 6.00 by 0.96-1.05, 1.02-1.28 and 1.11-1.73 log CFU/mL, respectively. The expression of two stress genes, rpoS and grxB, throughout gastric digestion was evaluated using reverse transcription qPCR. The upregulation of rpoS and grxB during the 4-h exposure to simulated gastric fluid at pH 4.00 showed that C. sakazakii strains may be experiencing the most stress in the pH 4.00 treatment. The gene expression results also suggest that C. sakazakii strains appeared to develop an acid adaptation response during the 4-h exposure that may facilitate their survival. Altogether, this study highlights that a combination of low gastric acidity, long digestion time in the presence of reconstituted PIF, created a favorable environment for the adaptation and survival of C. sakazakii in the simulation of a newborn's stomach. This study gives directions for future research to further advance our understanding of the behavior of C. sakazakii in the GI tract of newborns.


Asunto(s)
Proteínas Bacterianas , Cronobacter sakazakii , Fórmulas Infantiles , Cronobacter sakazakii/genética , Humanos , Recién Nacido , Proteínas Bacterianas/genética , Concentración de Iones de Hidrógeno , Lactante , Microbiología de Alimentos , Recuento de Colonia Microbiana , Contaminación de Alimentos/análisis , Factor sigma/genética , Factor sigma/metabolismo
12.
BMC Genom Data ; 25(1): 18, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38360573

RESUMEN

OBJECTIVE: Vibrio cholerae is an enteric pathogen that poses a significant threat to global health. It causes severe dehydrating diarrheal disease cholera in humans. V. cholerae could be acquired either from consuming contaminated seafood or direct contact with polluted waters. As part of a larger program that assesses the microbial community profile in aquatic systems, V. cholerae strain NB-183 was isolated and characterized using a combination of culture- and whole-genome sequencing-based approaches. DATA DESCRIPTION: Here we report the assembled and annotated whole-genome sequence of a V. cholerae strain NB-183 isolated from a recreational freshwater lake in Ontario, Canada. The genome was sequenced using short-read Illumina systems. The whole-genome sequencing yielded 4,112,549 bp genome size with 99 contigs with an average genome coverage of 96× and 47.42% G + C content. The whole genome-based comparison, phylogenomic and gene repertoire indicates that this strain harbors multiple virulence genes and biosynthetic gene clusters. This genome sequence and its associated datasets provided in this study will be an indispensable resource to enhance the understanding of the functional, ecological, and evolutionary dynamics of V. cholerae.


Asunto(s)
Cólera , Vibrio cholerae , Humanos , Vibrio cholerae/genética , Ontario , Virulencia/genética , Agua Dulce
13.
Microbiol Resour Announc ; 13(1): e0102623, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38099676

RESUMEN

Salmonella enterica is a zoonotic pathogen and a leading cause of foodborne gastroenteritis in humans. Here, we report the draft genome sequences of two Salmonella Uzaramo isolates, which were isolated from poultry organs during routine post-mortem examination in South Africa. Currently, whole-genome sequences on Salmonella Uzaramo are scanty.

14.
Microorganisms ; 12(4)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38674639

RESUMEN

Bacteriophages (phages) are potential alternatives to chemical antimicrobials against pathogens of public health significance. Understanding the diversity and host specificity of phages is important for developing effective phage biocontrol approaches. Here, we assessed the host range, morphology, and genetic diversity of eight Salmonella enterica phages isolated from a wastewater treatment plant. The host range analysis revealed that six out of eight phages lysed more than 81% of the 43 Salmonella enterica isolates tested. The genomic sequences of all phages were determined. Whole-genome sequencing (WGS) data revealed that phage genome sizes ranged from 41 to 114 kb, with GC contents between 39.9 and 50.0%. Two of the phages SB13 and SB28 represent new species, Epseptimavirus SB13 and genera Macdonaldcampvirus, respectively, as designated by the International Committee for the Taxonomy of Viruses (ICTV) using genome-based taxonomic classification. One phage (SB18) belonged to the Myoviridae morphotype while the remaining phages belonged to the Siphoviridae morphotype. The gene content analyses showed that none of the phages possessed virulence, toxin, antibiotic resistance, type I-VI toxin-antitoxin modules, or lysogeny genes. Three (SB3, SB15, and SB18) out of the eight phages possessed tailspike proteins. Whole-genome-based phylogeny of the eight phages with their 113 homologs revealed three clusters A, B, and C and seven subclusters (A1, A2, A3, B1, B2, C1, and C2). While cluster C1 phages were predominantly isolated from animal sources, cluster B contained phages from both wastewater and animal sources. The broad host range of these phages highlights their potential use for controlling the presence of S. enterica in foods.

15.
Sci Rep ; 14(1): 3728, 2024 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-38355869

RESUMEN

Wastewater surveillance of coronavirus disease 2019 (COVID-19) commonly applies reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to quantify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA concentrations in wastewater over time. In most applications worldwide, maximal sensitivity and specificity of RT-qPCR has been achieved, in part, by monitoring two or more genomic loci of SARS-CoV-2. In Ontario, Canada, the provincial Wastewater Surveillance Initiative reports the average copies of the CDC N1 and N2 loci normalized to the fecal biomarker pepper mild mottle virus. In November 2021, the emergence of the Omicron variant of concern, harboring a C28311T mutation within the CDC N1 probe region, challenged the accuracy of the consensus between the RT-qPCR measurements of the N1 and N2 loci of SARS-CoV-2. In this study, we developed and applied a novel real-time dual loci quality assurance and control framework based on the relative difference between the loci measurements to the City of Ottawa dataset to identify a loss of sensitivity of the N1 assay in the period from July 10, 2022 to January 31, 2023. Further analysis via sequencing and allele-specific RT-qPCR revealed a high proportion of mutations C28312T and A28330G during the study period, both in the City of Ottawa and across the province. It is hypothesized that nucleotide mutations in the probe region, especially A28330G, led to inefficient annealing, resulting in reduction in sensitivity and accuracy of the N1 assay. This study highlights the importance of implementing quality assurance and control criteria to continually evaluate, in near real-time, the accuracy of the signal produced in wastewater surveillance applications that rely on detection of pathogens whose genomes undergo high rates of mutation.


Asunto(s)
Monitoreo Epidemiológico Basado en Aguas Residuales , Aguas Residuales , Alelos , Mutación , Ontario/epidemiología , SARS-CoV-2/genética , ARN Viral/genética
16.
Sci Data ; 11(1): 656, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38906875

RESUMEN

During the COVID-19 pandemic, the Province of Ontario, Canada, launched a wastewater surveillance program to monitor SARS-CoV-2, inspired by the early work and successful forecasts of COVID-19 waves in the city of Ottawa, Ontario. This manuscript presents a dataset from January 1, 2021, to March 31, 2023, with RT-qPCR results for SARS-CoV-2 genes and PMMoV from 107 sites across all 34 public health units in Ontario, covering 72% of the province's and 26.2% of Canada's population. Sampling occurred 2-7 times weekly, including geographical coordinates, serviced populations, physico-chemical water characteristics, and flowrates. In doing so, this manuscript ensures data availability and metadata preservation to support future research and epidemic preparedness through detailed analyses and modeling. The dataset has been crucial for public health in tracking disease locally, especially with the rise of the Omicron variant and the decline in clinical testing, highlighting wastewater-based surveillance's role in estimating disease incidence in Ontario.


Asunto(s)
COVID-19 , SARS-CoV-2 , Aguas Residuales , Ontario/epidemiología , COVID-19/epidemiología , Aguas Residuales/virología , Humanos , Pandemias , Carga Viral
17.
Appl Environ Microbiol ; 79(13): 4094-105, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23624476

RESUMEN

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R(2) < 0.1) and between physicochemical indicators and Salmonella levels (R(2) < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression.


Asunto(s)
Escherichia coli/fisiología , Agua Dulce/microbiología , Salmonella/fisiología , Microbiología del Agua , Calidad del Agua/normas , Cartilla de ADN/genética , Florida , Concentración de Iones de Hidrógeno , Modelos Logísticos , Nefelometría y Turbidimetría , Reacción en Cadena de la Polimerasa , Dinámica Poblacional , Especificidad de la Especie , Temperatura
18.
Microbiol Resour Announc ; 12(4): e0126222, 2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-36912633

RESUMEN

Bacillus anthracis is widespread in soil and a causative agent of anthrax, primarily in herbivores. Here, we report the draft genome sequence of Bacillus anthracis strain N1, which was isolated from a recreational freshwater lake and found to carry multiple antibiotic resistance genes and biosynthetic gene clusters.

19.
Front Microbiol ; 14: 1086198, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36937281

RESUMEN

Introduction: Outbreak investigation of foodborne salmonellosis is hindered when the food source is contaminated by multiple strains of Salmonella, creating difficulties matching an incriminated organism recovered from patients with the specific strain in the suspect food. An outbreak of the rare Salmonella Adjame was caused by multiple strains of the organism as revealed by single-nucleotide polymorphism (SNP) variation. The use of highly discriminatory prophage analysis to characterize strains of Salmonella should enable a more precise strain characterization and aid the investigation of foodborne salmonellosis. Methods: We have carried out genomic analysis of S. Adjame strains recovered during the course of a recent outbreak and compared them with other strains of the organism (n = 38 strains), using SNPs to evaluate strain differences present in the core genome, and prophage sequence typing (PST) to evaluate the accessory genome. Phylogenetic analyses were performed using both total prophage content and conserved prophages. Results: The PST analysis of the S. Adjame isolates showed a high degree of strain heterogeneity. We observed small clusters made up of 2-6 isolates (n = 27) and singletons (n = 11) in stark contrast with the three clusters observed by SNP analysis. In total, we detected 24 prophages of which only four were highly prevalent, namely: Entero_p88 (36/38 strains), Salmon_SEN34 (35/38 strains), Burkho_phiE255 (33/38 strains) and Edward_GF (28/38 strains). Despite the marked strain diversity seen with prophage analysis, the distribution of the four most common prophages matched the clustering observed using core genome. Discussion: Mutations in the core and accessory genomes of S. Adjame have shed light on the evolutionary relationships among the Adjame strains and demonstrated a convergence of the variations observed in both fractions of the genome. We conclude that core and accessory genomes analyses should be adopted in foodborne bacteria outbreak investigations to provide a more accurate strain description and facilitate reliable matching of isolates from patients and incriminated food sources. The outcomes should translate to a better understanding of the microbial population structure and an 46 improved source attribution in foodborne illnesses.

20.
Microbiol Resour Announc ; 12(4): e0126122, 2023 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-36880761

RESUMEN

Exiguobacterium spp. are facultative anaerobic, Gram-positive, non-spore-forming bacilli, reported to tolerate extreme environments. Here, we report the draft genome sequence of Exiguobacterium sp. strain N5, isolated from a recreational freshwater lake.

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