spp. are responsible for significant losses in important wild and cultured fish species worldwide. Recent phylogenomic investigations have determined that bacteria historically classified as
actually ...represent three genetically distinct yet phenotypically ambiguous taxa with various degrees of pathogenicity in different hosts. Previous recognition of these taxa was hampered by the lack of a distinguishing phenotypic character. Commercial test panel configurations are relatively constant over time, and as new species are defined, appropriate discriminatory tests may not be present in current test panel arrangements. While phenobiochemical tests fail to discriminate between these taxa, data presented here revealed discriminatory peaks for each
species using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) methodology, suggesting that MALDI-TOF can offer rapid, reliable identification in line with current systematic classifications. Furthermore, a multiplex PCR assay was validated for rapid molecular differentiation of the
spp. affecting fish. Moreover, the limitations of relying on partial 16S rRNA for discrimination of
spp. and advantages of employing alternative single-copy genes
and
for molecular identification and classification of
were demonstrated. Last,
sequencing confirmed that isolates previously defined as typical motile fish-pathogenic
are synonymous with
, while atypical nonmotile fish-pathogenic
isolates are equivalent to
Fish-nonpathogenic
isolates are consistent with
as it is currently defined. These analyses help deconvolute the scientific literature regarding these organisms and provide baseline information to better facilitate proper taxonomic assignment and minimize erroneous identifications of
isolates in clinical and research settings.
Yersinia ruckeri is the causative agent of enteric redmouth disease in salmonids. Head kidney and spleen are major lymphoid organs of the teleost fish where antigen presentation and immune defense ...against microbes take place. We investigated proteome alteration in head kidney and spleen of the rainbow trout following Y. ruckeri strains infection. Organs were analyzed after 3, 9 and 28 days post exposure with a shotgun proteomic approach. GO annotation and protein-protein interaction were predicted using bioinformatic tools. Thirty four proteins from head kidney and 85 proteins from spleen were found to be differentially expressed in rainbow trout during the Y. ruckeri infection process. These included lysosomal, antioxidant, metalloproteinase, cytoskeleton, tetraspanin, cathepsin B and c-type lectin receptor proteins. The findings of this study regarding the immune response at the protein level offer new insight into the systemic response to Y. ruckeri infection in rainbow trout. This proteomic data facilitate a better understanding of host-pathogen interactions and response of fish against Y. ruckeri biotype 1 and 2 strains. Protein-protein interaction analysis predicts carbon metabolism, ribosome and phagosome pathways in spleen of infected fish, which might be useful in understanding biological processes and further studies in the direction of pathways.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Objectives
Implicit bias is common and is thought to drive discriminatory behaviour. Having previously demonstrated discrimination against specific applicant demographics by academic radiology ...departments in a simulated resident selection process, the authors sought to better understand the relationship between implicit bias and discrimination, as well as the potential and mechanisms for their mitigation.
Methods
A total of 51 faculty reviewers at three academic radiology departments, who had participated in a 2017 audit study in which they were shown to treat applicants differently based on race or ethnicity and physical appearance, were invited to complete testing for implicit racial and weight bias using the Implicit Association Test in 2019. Respondents were also surveyed regarding awareness of their own personal racial and weight biases, as well as any prior participation in formal diversity training. Comparisons were made between implicit bias scores and applicant ratings, as well as between diversity training and self‐awareness of bias.
Results
A total of 31 out of 51 faculty reviewers (61%) completed and submitted results of race and weight Implicit Association Tests. A total of 74% (23/31) reported implicit anti‐obese bias, concordant with discrimination demonstrated in the resident selection simulation, in which obese applicants were rated 0.40 standard deviations (SDs) lower than non‐obese applicants (P < .001). A total of 71% (22/31) reported implicit anti‐Black bias, discordant with application ratings, which were 0.47 SDs higher for Black than for White applicants (P < .001). A total of 84% (26/31) of participants reported feeling self‐aware of potential racial bias at the time of application review, significantly higher than the 23% (7/31) reporting self‐awareness of potential anti‐obese bias (P < .001). Participation in formal diversity training was not associated with implicit anti‐Black or anti‐fat bias, nor with self‐reported awareness of potential racial or weight‐based bias (all P > .2).
Conclusions
These findings suggest that implicit bias, as measured by the Implicit Association Test, does not inevitably lead to discrimination, and that personal awareness of implicit biases may allow their mitigation.
With countless reasons to worry about bias, discrimination in healthcare, education, Maxfield et al. offer hope by demonstrating that implicit bias does not inevitably lead to discrimination, can be managed.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Flavobacterium columnare causes columnaris disease in wild and cultured freshwater fish and is a major problem for sustainable aquaculture worldwide. The F. columnare type IX secretion system (T9SS) ...secretes many proteins and is required for virulence. The T9SS component GldN is required for secretion and gliding motility over surfaces. Genetic manipulation of F. columnare is inefficient, which has impeded identification of secreted proteins that are critical for virulence. Here, we identified a virulent wild-type F. columnare strain (MS-FC-4) that is highly amenable to genetic manipulation. This facilitated isolation and characterization of two deletion mutants lacking core components of the T9SS. Deletion of
disrupted protein secretion and gliding motility and eliminated virulence in zebrafish and rainbow trout. Deletion of
disrupted secretion and virulence but not motility. Both mutants exhibited decreased extracellular proteolytic, hemolytic, and chondroitin sulfate lyase activities. They also exhibited decreased biofilm formation and decreased attachment to fish fins and other surfaces. Using genomic and proteomic approaches, we identified proteins secreted by the T9SS. We deleted 10 genes encoding secreted proteins and characterized the virulence of mutants lacking individual or multiple secreted proteins. A mutant lacking two genes encoding predicted peptidases exhibited reduced virulence in rainbow trout, and mutants lacking a predicted cytolysin showed reduced virulence in zebrafish and rainbow trout. The results establish F. columnare strain MS-FC-4 as a genetically amenable model to identify virulence factors. This may aid development of measures to control columnaris disease and impact fish health and sustainable aquaculture.
Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish and is a major problem for aquaculture. Little is known regarding the virulence factors involved in this disease, and control measures are inadequate. The type IX secretion system (T9SS) secretes many proteins and is required for virulence, but the secreted virulence factors are not known. We identified a strain of F. columnare (MS-FC-4) that is well suited for genetic manipulation. The components of the T9SS and the proteins secreted by this system were identified. Deletion of core T9SS genes eliminated virulence. Genes encoding 10 secreted proteins were deleted. Deletion of two peptidase-encoding genes resulted in decreased virulence in rainbow trout, and deletion of a cytolysin-encoding gene resulted in decreased virulence in rainbow trout and zebrafish. Secreted peptidases and cytolysins are likely virulence factors and are targets for the development of control measures.
The flagellum is a complex surface structure necessary for a number of activities including motility, chemotaxis, biofilm formation and host attachment. Flagellin, the primary structural protein ...making up the flagellum, is an abundant and potent activator of innate and adaptive immunity and therefore expression of flagellin during infection could be deleterious to the infection process due to flagellin-mediated host recognition. Here, we use quantitative RT-PCR to demonstrate that expression of the flagellin locus fliC is repressed during the course of infection and subsequently up-regulated upon host mortality in a motile strain of Yersinia ruckeri. The kinetics of fliC repression during the infection process is relatively slow as full repression occurs 7-days after the initiation of infection and after approximately 3-logs of bacterial growth in vivo. These results suggests that Y. ruckeri possesses a regulatory system capable of sensing host and modulating the expression of motility in response. Examination of the master flagellar operon (flhDC) promoter region for evidence of transcriptional regulation and regulatory binding sites revealed potential interaction with the Rcs pathway through an Rcs(A)B Box. Deletion of rcsB (ΔrcsB) by marker-exchange mutagenesis resulted in overproduction of flagellin and unregulated motility, showing that the Rcs pathway negatively regulates biosynthesis of the flagellar apparatus. Experimental challenge with ΔrcsB and ΔrcsBΔfliC1ΔfliC2 mutants revealed that mutation of the Rcs pathway results in virulence attenuation which is dependent on presence of the flagellin gene. These results suggest that the inappropriate expression of flagellin during infection triggers host recognition and thus immune stimulation resulting in attenuation of virulence. In addition, RNAseq analyses of the ΔrcsB mutant strain verified the role of this gene as a negative regulator of the flagellar motility system and identified several additional genes regulated by the Rcs pathway.
•The Yersinia ruckeri flagellin gene is repressed during infection of rainbow trout.•This regulation is important for the virulence of this pathogen.•The RcsB regulatory system is necessary for flagellar regulation in Y. ruckeri.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
RNA polymerase II (pol II) encounters numerous barriers during transcription elongation, including DNA strand breaks, DNA lesions, and nucleosomes. Pyrrole-imidazole (Py-Im) polyamides bind to the ...minor groove of DNA with programmable sequence specificity and high affinity. Previous studies suggest that Py-Im polyamides can prevent transcription factor binding, as well as interfere with pol II transcription elongation. However, the mechanism of pol II inhibition by Py-Im polyamides is unclear. Here we investigate the mechanism of how these minor-groove binders affect pol II transcription elongation. In the presence of site-specifically bound Py-Im polyamides, we find that the pol II elongation complex becomes arrested immediately upstream of the targeted DNA sequence, and is not rescued by transcription factor IIS, which is in contrast to pol II blockage by a nucleosome barrier. Further analysis reveals that two conserved pol II residues in the Switch 1 region contribute to pol II stalling. Our study suggests this motif in pol II can sense the structural changes of the DNA minor groove and can be considered a “minor groove sensor.” Prolonged interference of transcription elongation by sequence-specific minor groove binders may present opportunities to target transcription addiction for cancer therapy.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM) of salmonids. There is little information regarding the proteomics of Y. ruckeri. Herein, we perform whole protein ...identification and quantification of biotype 1 and biotype 2 strains of Y. ruckeri grown under standard culture conditions using a shotgun proteomic approach. Proteins were extracted, digested and peptides were separated by a nano liquid chromatography system and analyzed with a high-resolution hybrid triple quadrupole time of flight mass spectrometer coupled via a nano ESI interface. SWATH-MS technology and sophisticated statistical analyses were used to identify proteome differences among virulent and avirulent strains. GO annotation, subcellular localization, virulence proteins and antibiotic resistance ontology were predicted using bioinformatic tools. A total of 1395 proteins were identified in the whole cell of Y. ruckeri. These included proteases, chaperones, cell division proteins, outer membrane proteins, lipoproteins, receptors, ion binding proteins, transporters and catalytic proteins. In virulent strains, a total of 16 proteins were upregulated including anti-sigma regulatory factor, arginine deiminase, phosphate-binding protein PstS and superoxide dismutase Cu-Zu. Additionally, several virulence proteins were predicted such as Clp and Lon pro-teases, TolB, PPIases, PstS, PhoP and LuxR family transcriptional regulators. These putative virulence proteins might be used for development of novel targets for treatment of ERM in fish. Our study represents one of the first global proteomic reference profiles of Y. ruckeri and this data can be accessed via ProteomeXchange with identifier PXD005439. These proteomic profiles elucidate proteomic mechanisms, pathogenicity, host-interactions, antibiotic resistance ontology and localization of Y. ruckeri proteins.
Equity of transit connectivity in Tennessee cities Sharma, Ishant; Mishra, Sabyasachee; Golias, Mihalis M. ...
Journal of transport geography,
June 2020, 2020-06-00, 20200601, Volume:
86
Journal Article
Peer reviewed
Federal and state agencies focus on providing captive users in mobility-vulnerable population groups with access to public transit resources. One challenge to the provision of equitable access is ...quantifying equity-oriented metrics for public transit service. This paper utilizes an approach that utilizes the available spatial demographic data and transit network characteristics to compute multimodal transit connectivity and equity. This method is exemplified by analyzing transit connectivity for three metropolitan cities in the state of Tennessee in the United States and overlapping that connectivity on demographic data. Results indicate that the distribution of transit services among vulnerable populations varies within and between cities. The case studies illustrate how this methodology can be used by public agencies to assess the performance of transit systems and to identify the distribution of these systems among various groups to improve the equity of transit connectivity.
•Utilizes open-source data to evaluate transit connectivity and equity.•Proposed concept applied to three major cities of Tennessee.•Transit distribution/equity among the population varies within and between cities.•Memphis's transit system: Most equitable with household income.•Nashville's transit system: Most equitable with vehicle ownership.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BACKGROUND:Combined practice in pediatric anesthesiology (PA) and pediatric critical care medicine (PCCM) was historically common but has declined markedly with time. The reasons for this temporal ...shift are unclear, but existing evidence suggests that length of training is a barrier to contemporary trainees. Among current practitioners, restriction in dual-specialty practice also occurs, for reasons that are unknown at present. We sought to describe the demographics of this population, investigate their perceptions about the field, and consider factors that lead to attrition.
METHODS:We conducted a cross-sectional, observational study of physicians in the United States with a combined practice in PA and PCCM. The survey was distributed electronically and anonymously to the distribution list of the Pediatric Anesthesia Leadership Council (PALC) of the Society for Pediatric Anesthesia (SPA), directing the recipients to forward the link to their faculty meeting our inclusion criteria. Attending-level respondents (n = 62) completed an anonymous, 40-question multidomain survey.
RESULTS:Forty-seven men and 15 women, with a median age of 51, completed the survey. Major leadership positions are held by 44%, and 55% are externally funded investigators. A minority (26%) have given up one or both specialties, citing time constraints and politics as the dominant reasons. Duration of training was cited as the major barrier to entry by 77%. Increasing age and faculty rank and lack of a comparably trained institutional colleague were associated with attrition from dual-specialty practice. The majority (88%) reported that they would do it all again.
CONCLUSIONS:The current cohort of pediatric anesthesiologist–intensivists in the United States is a small but accomplished group of physicians. Efforts to train, recruit, and retain such providers must address systematic barriers to completion of the requisite training and continued practice.
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