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1.
FASEB J ; 34(7): 9694-9712, 2020 07.
Article in English | MEDLINE | ID: mdl-32485054

ABSTRACT

Adenoviruses are responsible for a spectrum of pathogenesis including viral myocarditis. The gap junction protein connexin43 (Cx43, gene name GJA1) facilitates rapid propagation of action potentials necessary for each heartbeat. Gap junctions also propagate innate and adaptive antiviral immune responses, but how viruses may target these structures is not understood. Given this immunological role of Cx43, we hypothesized that gap junctions would be targeted during adenovirus type 5 (Ad5) infection. We find reduced Cx43 protein levels due to decreased GJA1 mRNA transcripts dependent upon ß-catenin transcriptional activity during Ad5 infection, with early viral protein E4orf1 sufficient to induce ß-catenin phosphorylation. Loss of gap junction function occurs prior to reduced Cx43 protein levels with Ad5 infection rapidly inducing Cx43 phosphorylation events consistent with altered gap junction conductance. Direct Cx43 interaction with ZO-1 plays a critical role in gap junction regulation. We find loss of Cx43/ZO-1 complexing during Ad5 infection by co-immunoprecipitation and complementary studies in human induced pluripotent stem cell derived-cardiomyocytes reveal Cx43 gap junction remodeling by reduced ZO-1 complexing. These findings reveal specific targeting of gap junction function by Ad5 leading to loss of intercellular communication which would contribute to dangerous pathological states including arrhythmias in infected hearts.


Subject(s)
Adenoviridae Infections/pathology , Adenoviridae/physiology , Cell Communication , Connexin 43/metabolism , Gap Junctions/pathology , Myocytes, Cardiac/pathology , Transcription, Genetic , Adenoviridae Infections/metabolism , Adenoviridae Infections/virology , Cells, Cultured , Connexin 43/genetics , Gap Junctions/virology , Gene Expression Regulation , HEK293 Cells , Humans , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/virology , Phosphorylation
2.
BJOG ; 128(7): 1145-1150, 2021 06.
Article in English | MEDLINE | ID: mdl-33184969

ABSTRACT

OBJECTIVE: To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term. DESIGN: A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term. SETTING: Nova Scotia, Canada. POPULATION: All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019. METHODS: Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not. MAIN OUTCOME MEASURES: Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity. RESULTS: Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54). CONCLUSIONS: Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.


Subject(s)
Obstetric Labor, Premature/epidemiology , Cohort Studies , Female , Gestational Age , Glucocorticoids/therapeutic use , Humans , Infant, Low Birth Weight , Infant, Newborn , Nova Scotia/epidemiology , Perinatal Mortality , Pregnancy , Pregnancy Complications/epidemiology , Puerperal Disorders/epidemiology , Tocolytic Agents/therapeutic use
3.
J Antimicrob Chemother ; 75(12): 3485-3490, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32830242

ABSTRACT

BACKGROUND: The incidence of antimicrobial-resistant Neisseria gonorrhoeae (GC) is rising in Canada; however, antimicrobial resistance (AMR) surveillance data are unavailable for infections diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs), representing over 80% of diagnoses. We developed a set of 10 improved molecular assays for surveillance of GC-AMR and prediction of susceptibilities in NAAT specimens. METHODS: Multiplex real-time PCR (RT-PCR) assays were developed to detect SNPs associated with cephalosporin (ponA, porB, mtrR -35delA, penA A311V, penA A501, N513Y, G545S), ciprofloxacin (gyrA S91, parC D86/S87/S88) and azithromycin [23S (A2059G, C2611T), mtrR meningitidis-like promoter] resistance. The assays were validated on 127 gonococcal isolates, 51 non-gonococcal isolates and 50 NAATs with matched culture isolates. SNPs determined from the assay were compared with SNPs determined from in silico analysis of WGS data. MICs were determined for culture isolates using the agar dilution method. RESULTS: SNP analysis of the 50 NAAT specimens had 96% agreement with the matched culture RT-PCR analysis. When compared with MICs, presence of penA A311V or penA A501 and two or more other SNPs correlated with decreased susceptibility and presence of three or more other SNPs correlated with intermediate susceptibility to cephalosporins; presence of any associated SNP correlated with ciprofloxacin or azithromycin resistance. NAAT-AMR predictions correlated with matched-culture cephalosporin, ciprofloxacin and azithromycin MICs at 94%, 100% and 98%, respectively. CONCLUSIONS: We expanded molecular tests for N. gonorrhoeae AMR prediction by adding new loci and multiplexing reactions to improve surveillance where culture isolates are unavailable.


Subject(s)
Gonorrhea , Neisseria gonorrhoeae , Anti-Bacterial Agents/pharmacology , Azithromycin/pharmacology , Canada , Cephalosporins/pharmacology , Ciprofloxacin/pharmacology , Drug Resistance, Bacterial , Humans , Microbial Sensitivity Tests , Neisseria gonorrhoeae/genetics , Real-Time Polymerase Chain Reaction
4.
Br J Dermatol ; 183(3): 443-451, 2020 09.
Article in English | MEDLINE | ID: mdl-31794059

ABSTRACT

BACKGROUND: Epidemiological studies indicate that gene-environment interactions play a role in atopic dermatitis (AD). OBJECTIVES: To review the evidence for gene-environment interactions in AD aetiology, focusing on filaggrin (FLG) loss-of-function mutations. METHODS: A systematic search from inception to September 2018 in Embase, MEDLINE and BIOSIS was performed. Search terms included all synonyms for AD and filaggrin/FLG; any genetic or epidemiological study design using any statistical methods were included. Quality assessment using criteria modified from guidance (ROBINS-I and Human Genome Epidemiology Network) for nonrandomized and genetic studies was completed, including consideration of power. Heterogeneity of study design and analyses precluded the use of meta-analysis. RESULTS: Of 1817 papers identified, 12 studies fulfilled the inclusion criteria required and performed formal interaction testing. There was some evidence for FLG-environment interactions in six of the studies (P-value for interaction ≤ 0·05), including early-life cat ownership, older siblings, water hardness, phthalate exposure, higher urinary phthalate metabolite levels (which all increased AD risk additional to FLG null genotype) and prolonged breastfeeding (which decreased AD risk in the context of FLG null genotype). Major limitations of published studies were the low numbers of individuals (ranging from five to 94) with AD and FLG loss-of-function mutations and exposure to specific environmental factors, and variation in exposure definitions. CONCLUSIONS: Evidence on FLG-environment interactions in AD aetiology is limited. However, many of the studies lacked large enough sample sizes to assess these interactions fully. Further research is needed with larger sample sizes and clearly defined exposure assessment. Linked Comment: Park and Seo. Br J Dermatol 2020; 183:411.


Subject(s)
Dermatitis, Atopic , Animals , Cats , Dermatitis, Atopic/etiology , Dermatitis, Atopic/genetics , Environmental Exposure/adverse effects , Filaggrin Proteins , Genetic Predisposition to Disease/genetics , Genotype , Intermediate Filament Proteins/genetics , Loss of Function Mutation , Mutation
5.
J Appl Microbiol ; 128(6): 1776-1784, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31917894

ABSTRACT

AIM: Following previous research on improving the cleaning of crates used to transport broiler chickens from the farm to the abattoir, a demonstration project was undertaken to investigate improvements in crate washing on a commercial scale. METHODS AND RESULTS: The soak tank of a conventional crate washing system was replaced with a high-performance washer fitted with high-volume, high-pressure nozzles. The wash water could be heated, and a greatly improved filtration system ensured that the nozzles did not lose performance or become blocked. Visual cleanliness scores and microbial counts were determined for naturally contaminated crates which had been randomly assigned to different cleaning protocols. CONCLUSIONS: When a combination of mechanical energy, heat and chemicals (i.e. detergent and disinfectant) was used, the results showed significant improvements to crate cleaning. Reductions of up to 3·6 and 3·8 log10 CFU per crate base were achieved for Campylobacter and Enterobacteriaceae, respectively, along with a marked improvement in visual cleanliness. SIGNIFICANCE AND IMPACT OF THE STUDY: Broiler transport crates may become heavily contaminated with faeces and this may contribute to the spread of disease between farms. The results of this trial may be of use in reducing the spread of zoonotic pathogens in the poultry meat supply chain.


Subject(s)
Chickens/microbiology , Disinfection/methods , Food Contamination/prevention & control , Food Handling/methods , Poultry/microbiology , Animals , Campylobacter/drug effects , Campylobacter/isolation & purification , Disinfectants/pharmacology , Disinfection/instrumentation , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Equipment Design , Food Handling/instrumentation , Food Microbiology , United Kingdom
6.
Aging Ment Health ; 23(1): 1-14, 2019 01.
Article in English | MEDLINE | ID: mdl-29148830

ABSTRACT

OBJECTIVES: This review examines differences in the use of emotion regulation (ER) strategies among younger and older adults. METHOD: A systematic review using search terms related to ageing and ER identified 23 relevant studies. Narrative synthesis was adopted to analyse the findings. RESULTS: Generally, greater use of situation selection and attentional deployment was identified among older adults, although these relationships were dependent on contextual/moderator variables. While older adults employed greater levels of situation modification in response to negative stimuli, there was considerable variation in age differences across specific situation modification subtypes. Available evidence pointed to an absence of age differences in the cognitive change strategy of cognitive reappraisal. The use of relatively less-cognitively demanding cognitive change subtypes (e.g. acceptance) was, under particular circumstances, greater among older adults. Findings regarding the response modulation strategy of expressive suppression were equivocal. CONCLUSION: Adult development is not characterised by straightforward shifts in preferences for use of different ER strategies. Moderator variables appear to be of central importance in shaping the emergence of age differences in ER. Systematically examining interactions of age with individual difference variables and situational factors in samples including oldest-old adults will be important for advancing knowledge regarding developmental differences in ER.


Subject(s)
Cognition , Emotional Regulation , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Attention , Female , Humans , Male , Middle Aged , Self Efficacy , Young Adult
7.
J Clin Microbiol ; 55(5): 1454-1468, 2017 05.
Article in English | MEDLINE | ID: mdl-28228492

ABSTRACT

A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA, mtrR, porB, ponA, gyrA, parC, and 23S rRNA) associated with resistance to ß-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA, porB, gyrA, and parC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs (n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 (n = 100; 13.0%), ST-42 and ST-91 (n = 45; 5.9%), ST-64 (n = 44; 5.72%), and ST-139 (n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 (n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 (n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 (n = 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 (n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Multilocus Sequence Typing/methods , Neisseria gonorrhoeae/classification , Neisseria gonorrhoeae/drug effects , Amino Acid Sequence , Azithromycin/pharmacology , Cephalosporins/pharmacology , Fluoroquinolones/pharmacology , Gonorrhea/epidemiology , Gonorrhea/microbiology , Humans , Neisseria gonorrhoeae/genetics , Neisseria gonorrhoeae/isolation & purification
8.
J Zool (1987) ; 303(3): 178-187, 2017 11.
Article in English | MEDLINE | ID: mdl-29200662

ABSTRACT

Human patellae (kneecaps) are thought to act as gears, altering the mechanical advantage of knee extensor muscles during running. Similar sesamoids have evolved in the knee extensor tendon independently in birds, but it is unknown if these also affect the mechanical advantage of knee extensors. Here, we examine the mechanics of the patellofemoral joint in the helmeted guineafowl Numida meleagris using a method based on muscle and tendon moment arms taken about the patella's rotation centre around the distal femur. Moment arms were estimated from a computer model representing hindlimb anatomy, using hip, knee and patellar kinematics acquired via marker-based biplanar fluoroscopy from a subject running at 1.6 ms-1 on a treadmill. Our results support the inference that the patella of Numida does alter knee extensor leverage during running, but with a mechanical advantage generally greater than that seen in humans, implying relatively greater extension force but relatively lesser extension velocity.

9.
Emerg Infect Dis ; 22(1): 65-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26689114

ABSTRACT

Antimicrobial resistance profiles were determined for Neisseria gonorrhoeae strains isolated in Canada during 2010-2014. The proportion of isolates with decreased susceptibility to cephalosporins declined significantly between 2011 and 2014, whereas azithromycin resistance increased significantly during that period. Continued surveillance of antimicrobial drug susceptibilities is imperative to inform treatment guidelines.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Azithromycin/therapeutic use , Cephalosporins/therapeutic use , Drug Resistance, Bacterial/drug effects , Gonorrhea/drug therapy , Neisseria gonorrhoeae/drug effects , Canada , Humans , Microbial Sensitivity Tests/methods
10.
J Clin Microbiol ; 53(7): 2042-8, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25878350

ABSTRACT

The incidence of antimicrobial-resistant Neisseria gonorrhoeae continues to rise in Canada; however, antimicrobial resistance data are lacking for approximately 70% of gonorrhea infections that are diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs). We developed a molecular assay for surveillance use to detect mutations in genes associated with decreased susceptibility to cephalosporins that can be applied to both culture isolates and clinical samples. Real-time PCR assays were developed to detect single nucleotide polymorphisms (SNPs) in ponA, mtrR, penA, porB, and one N. gonorrhoeae-specific marker (porA). We tested the real-time PCR assay with 252 gonococcal isolates, 50 nongonococcal isolates, 24 N. gonorrhoeae-negative NAAT specimens, and 34 N. gonorrhoeae-positive NAAT specimens. Twenty-four of the N. gonorrhoeae-positive NAAT specimens had matched culture isolates. Assay results were confirmed by comparison with whole-genome sequencing data. For 252 N. gonorrhoeae strains, the agreement between the DNA sequence and real-time PCR was 100% for porA, ponA, and penA, 99.6% for mtrR, and 95.2% for porB. The presence of ≥2 SNPs correlated with decreased susceptibility to ceftriaxone (sensitivities of >98%) and cefixime (sensitivities of >96%). Of 24 NAAT specimens with matched cultures, the agreement between the DNA sequence and real-time PCR was 100% for porB, 95.8% for ponA and mtrR, and 91.7% for penA. We demonstrated the utility of a real-time PCR assay for sensitive detection of known markers for the decreased susceptibility to cephalosporins in N. gonorrhoeae. Preliminary results with clinical NAAT specimens were also promising, as they correlated well with bacterial culture results.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Drug Resistance, Bacterial , Genetic Markers , Genotyping Techniques/methods , Neisseria gonorrhoeae/drug effects , Neisseria gonorrhoeae/genetics , Canada , Female , Genes, Bacterial , Gonorrhea/microbiology , Humans , Male , Microbiological Techniques/methods , Polymorphism, Single Nucleotide , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity
11.
J Clin Microbiol ; 53(11): 3606-8, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26292300

ABSTRACT

We developed a real-time PCR assay to detect single nucleotide polymorphisms associated with ciprofloxacin resistance in specimens submitted for nucleic acid amplification testing (NAAT). All three single nucleotide polymorphism (SNP) targets produced high sensitivity and specificity values. The presence of ≥2 SNPs was sufficient to predict ciprofloxacin resistance in an organism.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Drug Resistance, Bacterial/genetics , Neisseria gonorrhoeae/drug effects , Neisseria gonorrhoeae/genetics , Nucleic Acid Amplification Techniques/methods , Canada , Cross Reactions , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Gonorrhea/diagnosis , Gonorrhea/microbiology , Humans , Microbial Sensitivity Tests , Neisseria gonorrhoeae/isolation & purification , Polymerase Chain Reaction/methods , Polymorphism, Single Nucleotide/genetics , Sensitivity and Specificity
12.
Br Poult Sci ; 56(1): 48-57, 2015.
Article in English | MEDLINE | ID: mdl-25654335

ABSTRACT

1. The onset and progression of Salmonella infections was investigated in commercial turkey flocks from placement at 1 d old until slaughter in "brood and move" systems using a longitudinal observational approach based on faeces and environmental sampling with subsequent culture of Salmonella. 2. Persistent Salmonella Newport contamination was found within rearing houses and on their external concrete aprons after cleaning and disinfection between crops of heavily shedding young birds. 3. Salmonella shedding was often detected by 5 d of age and the frequency of positive samples peaked at 14-35 d. Thereafter Salmonella isolations declined, especially in the later (fattening) stages. Samples were still Salmonella-positive at low prevalence in half of the intensively sampled houses at slaughter age. 4. A number of management interventions to combat Salmonella infection of flocks, including sourcing policy, competitive exclusion cultures and cleaning and disinfection, were inadequate to prevent flock infection, although improved disinfection on one unit was associated with a delay in the onset of flock infection.


Subject(s)
Environmental Microbiology , Poultry Diseases/epidemiology , Poultry Diseases/prevention & control , Salmonella Infections, Animal/epidemiology , Salmonella Infections, Animal/prevention & control , Salmonella/isolation & purification , Turkeys , Animals , Disinfection , Feces/microbiology , Longitudinal Studies , Poultry Diseases/microbiology , Prevalence , Salmonella Infections, Animal/microbiology , United Kingdom/epidemiology
13.
Epidemiol Infect ; 142(9): 1884-92, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24252175

ABSTRACT

Campylobacter is a common cause of intestinal disease in humans and is often linked to the consumption of contaminated poultry meat. Despite considerable research on the topic there is a large amount of uncertainty associated with Campylobacter epidemiology. A Bayesian model framework was applied to multiple longitudinal datasets on Campylobacter infection in UK broiler flocks to estimate the time at which each flock was first infected with Campylobacter. The model results suggest that the day of first infection ranges from 10 to 45 days; however, over half had a time of infection between 30 and 35 days. When considering only those flocks which were thinned, 48% had an estimated day of infection within 2 days of the day of thinning, thus suggesting an association between thinning and Campylobacter infection. These results demonstrate how knowledge of the time of infection can be correlated to known events to identify potential risk factors for infection.


Subject(s)
Campylobacter Infections/veterinary , Chickens , Poultry Diseases/microbiology , Animals , Bayes Theorem , Campylobacter Infections/epidemiology , Campylobacter Infections/microbiology , Poultry Diseases/epidemiology , Risk Factors , Time Factors , United Kingdom/epidemiology
14.
Epidemiol Infect ; 142(7): 1411-21, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24029072

ABSTRACT

In Ontario, Canada, the number of Salmonella Enteritidis (SE) cases increased over the years 2005-2010. A population-based case-control study was undertaken from January to August 2011 for the purpose of identifying risk factors for acquiring illness due to SE within Ontario. A total of 199 cases and 241 controls were enrolled. After adjustment for confounders, consuming any poultry meat [adjusted odds ratio (aOR) 2·24, 95% confidence interval (CI) 1·31-3·83], processed chicken (aOR 3·32, 95% CI 1·26-8·76) and not washing hands following handling of raw eggs (OR 2·82, 95% CI 1·48-5·37) were significantly associated with SE infection. The population attributable fraction was 46% for any poultry meat consumption and 10% for processed chicken. Poultry meat continues to be identified as a risk factor for SE illness. Control of SE at source, as well as proper food handling practices, are required to reduce the number of SE cases.


Subject(s)
Community-Acquired Infections/epidemiology , Salmonella Infections/epidemiology , Salmonella enteritidis/isolation & purification , Adolescent , Adult , Animals , Case-Control Studies , Chickens , Child , Child, Preschool , Community-Acquired Infections/microbiology , Eggs/microbiology , Feeding Behavior , Female , Hand Disinfection , Humans , Infant , Male , Meat/microbiology , Middle Aged , Multivariate Analysis , Odds Ratio , Ontario/epidemiology , Risk Factors , Salmonella Infections/microbiology , Surveys and Questionnaires , Young Adult
15.
Appl Environ Microbiol ; 79(20): 6472-80, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23956391

ABSTRACT

Listeria monocytogenes is responsible for severe and often fatal food-borne infections in humans. A collection of 2,421 L. monocytogenes isolates originating from Ontario's food chain between 1993 and 2010, along with Ontario clinical isolates collected from 2004 to 2010, was characterized using an improved multilocus variable-number tandem-repeat analysis (MLVA). The MLVA method was established based on eight primer pairs targeting seven variable-number tandem-repeat (VNTR) loci in two 4-plex fluorescent PCRs. Diversity indices and amplification rates of the individual VNTR loci ranged from 0.38 to 0.92 and from 0.64 to 0.99, respectively. MLVA types and pulsed-field gel electrophoresis (PFGE) patterns were compared using Comparative Partitions analysis involving 336 clinical and 99 food and environmental isolates. The analysis yielded Simpson's diversity index values of 0.998 and 0.992 for MLVA and PFGE, respectively, and adjusted Wallace coefficients of 0.318 when MLVA was used as a primary subtyping method and 0.088 when PFGE was a primary typing method. Statistical data analysis using BioNumerics allowed for identification of at least 8 predominant and persistent L. monocytogenes MLVA types in Ontario's food chain. The MLVA method correctly clustered epidemiologically related outbreak strains and separated unrelated strains in a subset analysis. An MLVA database was established for the 2,421 L. monocytogenes isolates, which allows for comparison of data among historical and new isolates of different sources. The subtyping method coupled with the MLVA database will help in effective monitoring/prevention approaches to identify environmental contamination by pathogenic strains of L. monocytogenes and investigation of outbreaks.


Subject(s)
Genetic Variation , Listeria monocytogenes/classification , Listeria monocytogenes/genetics , Minisatellite Repeats , Molecular Typing/methods , Cluster Analysis , DNA Primers/genetics , Electrophoresis, Gel, Pulsed-Field , Food Microbiology , Genotype , Humans , Listeria monocytogenes/isolation & purification , Listeriosis/microbiology , Ontario
16.
Curr Biol ; 33(13): 2784-2793.e3, 2023 07 10.
Article in English | MEDLINE | ID: mdl-37343556

ABSTRACT

Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from those of other highly visual species, such as vertebrates; therefore, the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, as there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. An examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods.


Subject(s)
Octopodiformes , Animals , Eye , Visual Perception , Nervous System , Visual Pathways/physiology
17.
bioRxiv ; 2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36824726

ABSTRACT

Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from that of other highly visual species, such as vertebrates, and therefore the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, since there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. Examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods. Highlights: The functional organization and visual response properties of the cephalopod visual system are largely unknownUsing calcium imaging, we performed mapping of visual responses in the octopus optic lobeVisual responses demonstrate localized ON and OFF receptive fields with retinotopic organizationON/OFF pathways and size selectivity emerge across layers of the optic lobe and have distinct properties relative to other species.

18.
Epidemiol Infect ; 140(5): 916-24, 2012 May.
Article in English | MEDLINE | ID: mdl-21781366

ABSTRACT

Campylobacter is the most common known source of human bacterial enteritis in the developed world and poultry is considered the main source. Broilers often become colonized with Campylobacter during rearing, and then contaminate the farm environment. The objective of this study was to identify Campylobacter-positive environmental reservoirs on farms, as these pose a risk to broiler flocks becoming colonized with Campylobacter. We considered the temporal aspects of exposure and colonization. A longitudinal study monitored six conventional rearing farms over 2 years. The broiler flocks, catchers' equipment, vehicles, shed surrounds, shed entrance, other equipment, farm entrance, other animals, puddles, dead birds, mains water and drinkers were systematically sampled 2-4 times per flock. A multivariable generalized estimating equation model was used to assess associations between contaminated environmental sites and colonized broiler flocks. The associations were adjusted for confounders and other known risk factors. To further assess temporality of contamination, the sequence of contamination of the different environmental sites and the flocks was established. Contaminated shed entrances and anterooms, contaminated drinkers and shedding of Campylobacter by other animals such as cattle, dogs, wildlife and rodents were significantly associated with positive flocks. The reservoir of 'other animals' was also the reservoir most commonly positive before the flock became colonized. The other sites usually became contaminated after the flock was colonized.


Subject(s)
Campylobacter Infections/epidemiology , Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Chickens , Disease Reservoirs , Environmental Microbiology , Poultry Diseases/epidemiology , Animals , Cattle , Dogs , Humans , Longitudinal Studies , Risk Factors
19.
J Food Prot ; 85(12): 1696-1707, 2022 12 01.
Article in English | MEDLINE | ID: mdl-36135722

ABSTRACT

ABSTRACT: As part of a program to reduce numbers of the human pathogen Campylobacter on retail chickens, 22 broiler processing lines, representing more than 90% of UK production, were characterized by enumerating Campylobacter on pooled neck skins after exsanguination, scalding, defeathering, evisceration, crop removal, inside-outside washing, and air-chilling stages of processing. Sixteen of the processing lines investigated showed significant (P < 0.05) reductions in Campylobacter numbers because of carcass scalding. However, in all of these lines, the following defeathering stage caused a significant increase in Campylobacter contamination that effectively negated the reductions caused by scalding. On four processing lines, primary chilling also caused a significant reduction in numbers of Campylobacter. On three lines, there was a significant microbiological benefit from inside-outside washing. The stages where Campylobacter numbers were reduced require further investigation to determine the specific mechanisms responsible so that the observed pathogen reductions can be optimized and then more widely implemented. The transfer of up to 4 log CFU Campylobacter per g of neck skin from a colonized flock to a following uncolonized flock was observed. Cross-contamination was substantial and still detectable after 5,000 carcasses from an uncolonized flock had been processed. Numbers of Campylobacter recovered from the uncolonized flocks were highest on the first of the uncolonized birds to pass along the line, and in general, the numbers declined as more uncolonized birds were processed. Air sampling recovered low numbers at the processing stages monitored, indicating that airborne transmission was unlikely to be the primary transfer mechanism operating for cross-contamination between flocks.


Subject(s)
Campylobacter , Humans , Animals , Chickens/microbiology , Abattoirs , Food Microbiology , Colony Count, Microbial , United Kingdom , Food Handling , Food Contamination/analysis , Meat/microbiology
20.
Br J Cancer ; 105(3): 340-5, 2011 Jul 26.
Article in English | MEDLINE | ID: mdl-21750554

ABSTRACT

BACKGROUND: Studies have shown limited awareness about cancer risk factors among hospital-based staff. Less is known about general cancer awareness among community frontline National Health Service and social care staff. METHODS: A cross-sectional computer-assisted telephone survey of 4664 frontline community-based health and social care staff in North West England. RESULTS: A total of 671 out of 4664 (14.4%) potentially eligible subjects agreed to take part. Over 92% of staff recognised most warning signs, except an unexplained pain (88.8%, n=596), cough or hoarseness (86.9%, n=583) and a sore that does not heal (77.3%, n=519). The bowel cancer-screening programme was recognised by 61.8% (n=415) of staff. Most staff agreed that smoking and passive smoking 'increased the chance of getting cancer.' Fewer agreed about getting sunburnt more than once as a child (78.0%, n=523), being overweight (73.5%, n=493), drinking more than one unit of alcohol per day (50.2%, n=337) or doing less than 30 min of moderate physical exercise five times a week (41.1%, n=276). CONCLUSION: Cancer awareness is generally good among frontline staff, but important gaps exist, which might be improved by targeted education and training and through developing clearer messages about cancer risk factors.


Subject(s)
Health Knowledge, Attitudes, Practice , Health Personnel/education , Neoplasms/etiology , Social Work/education , Adult , Cross-Sectional Studies , Early Detection of Cancer , Female , Health Education , Humans , Interviews as Topic , Male , Middle Aged , Risk Factors , United Kingdom
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