bluuebunny/crossref_metadata_2025 huggingface dataset:
Role for the phosphatidylinositol 3-phosphate 5-kinase in antifungal tolerance in Candida glabrata
Authors: Kaur Rupinder
Published: December 2021

Candida glabrata is an opportunistic fungal pathogen of humans, which is intrinsically less susceptible to widely used azole antifungals, that block ergosterol biosynthesis. The major azole resistance mechanisms include mitochondrial dysfunction and multidrug efflux pump overexpression. In the current study, we have uncovered an essential role for the actin cytoskeletal network reorganization in survival of the azole stress. We demonstrate for the first time that the azole antifungal fluconazole induces remodelling of the actin cytoskeleton in C. glabrata, and genetic or chemical perturbation of actin structures results in intracellular sterol accumulation and azole susceptibility. Further, we showed that the vacuolar membrane-resident phosphatidylinositol 3-phosphate 5-kinase (CgFab1) is pivotal to this process, as CgFAB1 disruption impaired vacuole homeostasis and actin organization. We also showed that the actin depolymerization factor CgCof1 binds to phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2), and CgCof1 distribution along with the actin filament-capping protein CgCap2 is altered upon both CgFAB1disruption and fluconazole exposure. Additionally, while the F-actin-stabilizing compound jasplakinolide rescued azole toxicity in cytoskeleton defective-mutants, the actin polymerization inhibitor latrunculin B rendered fluconazole fully and partially fungicidal in azole-susceptible and azole-resistant C. glabrata clinical isolates, respectively. These data underscore the essentiality of actin cytoskeleton reorganization for azole stress survival. Lastly, we have also shown a pivotal role of CgFab1 kinase activity regulators, CgFig4, CgVac7 and CgVac14, through genetic analysis, in azole and echinocandin antifungal tolerance. Altogether, I shall present our findings on functions and metabolism of the PI(3,5)P2 lipid in antifungal tolerance and virulence of C. glabrata.
Recovery of Candida spp. from a denture rat model
Authors: Sakima Vinicius Tatsuyuji , Chacón Yuliana del Pilar Vega , Soares Amanda Brandão , de Oliveira Mima Ewerton Garcia
Published: December 2021

Denture stomatitis is a common infection in denture wearers. This study evaluated the recovery of Candida spp. from the palate of Wistar rats after using an acrylic device with single and mixed-species of Candida spp. After approval of the Ethics Committee, 84 male and female Wistar rats were used. Custom-made acrylic devices were fabricated for each animal and sterilized by microwave irradiation. Single and mixed species biofilms of C. albicans (Ca), C. glabrata (Cg), and C. tropicalis (Ct) were grown on the devices for 48 h at 37°C. Rats were anesthetized and the devices were cemented on the molar teeth (n=5 for each sex and Candida spp.). Rats received a carbohydrate-rich diet. Single and mixed species were inoculated in the oral cavity thrice after three-day intervals. Controls received only dentures without Candida spp. After 4 weeks, the devices were removed, the palates were swabbed, and diluted samples were plated on Agar Sabouraud Dextrose and CHROMAgar Candida for colony counting and presumptive identification, respectively, after 48 h. Data were analyzed by 3way ANOVA (α=5%). There was a significant interaction (p=0.003) between sex and species. For females, all groups recovered significant values (p≤0.027) compared with controls. For males, groups with Ct as single and dual-species showed the lowest values without difference (p≥0.183) with the control. The groups with triple-species showed the highest values but without difference (p≥0.071) with the groups with single and dual-species, except males with Ct. Ct alone showed reduced recovery from palate of male rats.
Tell me what type of extracellular vesicles you secrete, and I will tell you who you are: yeast or hypha
Authors: Martínez-López Raquel , Vaz Catarina , Redondo Esther , Calvo Guillermo , Hernáez María Luisa , Gil Concha , Monteoliva Lucía
Published: December 2021

The transition between yeast and hyphal morphologies plays a crucial role in the pathogenicity of Candida albicans. Recent studies have pointed out the great relevance of extracellular vesicles (EVs) secreted by microorganisms in a wide variety of biological processes including interaction with the host. Therefore, the main objective of this work was to compare the EVs secreted by yeast and hyphal forms to shed light on C. albicans-host interaction.

EVs were obtained by ultracentrifugation of the culture medium supernatant and analysed by mass spectrometry. They were characterized by transmission electronic microscopy (TEM) and dynamic light scattering (DLS).

DLS and TEM analysis showed that yeast EVs were significantly bigger than hyphal EVs, being most of them in the range between 400 to 500nm while hyphal EVs were ranged mostly around 100-200nm.

Proteomic analysis showed greater protein diversity in hyphal EVs when compared to yeast EVs (up to 1700 different proteins identified versus 300), although less amount of total protein was obtained. Gene Ontology (GO) analysis showed that yeast EVs were enriched in surface proteins while hyphal EVs, although containing also most of these surface proteins, were also significantly and exclusively enriched in proteins involved in protein metabolism (ribosomal proteins, many aminoacid-pathway enzymes and proteasome) and cellular transport. The differences between YEVs and HEVs also prompted a different immune host response, as tested with macrophage cell cultures and human sera from patients with invasive candidiasis.

All these differences point out a possible different biogenesis and roles of EVs secreted by both morphologies.
A systemic analysis of amino acid transporters identifies Gnp2 as the main proline permease in Candida albicans
Authors: Garbe Enrico , Miramon Pedro , Gerwien Franziska , Lorenz Michael , Vylkova Slavena
Published: December 2021

The tight association of Candida albicans with the human host has driven the evolution of mechanisms that permit metabolic flexibility. Amino acids, present in free form or peptide bound, are an abundant carbon and nitrogen source in many host niches. Further,the capacity to sense and utilize certain amino acids, like proline, is directly linked to virulence. The C. albicans genome encodes for at least 24 amino acid permeases (AAPs), highlighting the importance of flexible amino acid uptake for fungal growth and virulence. Although the substrate specificity and role of certain AAPs has been investigated, a comprehensive characterization was missing. Therefore, we assembled a library of AAP deletion strains, which was tested for resistance to toxic amino acid analogs. Most striking was the specific resistance of gnp2Δ to the proline analog 3,4-dehydroproline. Subsequent tests validated that Gnp2 is a specific proline permease in C. albicans, which is contrary to the model yeast Saccharomyces cerevisiae where proline transport is mediated by four permeases. Furthermore, the induction of GNP2 appears to be independent of the SPS (Ssy1-Ptr3-Ssy5) regulatory pathway that controls proline utilization in the model yeast, pointing towards rewired proline uptake in C. albicans. Additionally, strains lacking GNP2were unable to respond to proline-induced filamentation, displayed decreased cytotoxicity to macrophages and showed increased sensitivity to oxidative stress, underlining the importance of proline uptake for fungal virulence. Taken together, the role of Gnp2-mediated proline uptake illustrates the importance of metabolism-driven virulence in C. albicans.
Candida glabrata MSH2 deletion increases antifungal tolerance in vitro and during intra-abdominal candidiasis (IAC), it does not impact pathogenesis of peritonitis or intra-abdominal abscesses
Authors: Cheng Shaoji , Liu Guojun , Clancy Cornelius Joseph , Thi Nguyen Minh Hong
Published: December 2021

Background:

IAC is the second most common type of invasive Candidiasis, but its pathogenesis is poorly understood. We have shown that Candida albicans DNA damage response genes are strongly induced within intra-abdominal abscesses. Deletion of C. glabrata MSH2, A DNA mismatch repair (MMR) gene, results in a mutator phenotype that facilitates multidrug resistance in vitro and in mouse gastrointestinal tracts. Our goal was to determine if CGMSH2 Contributed to pathogenesis or resistance to the new antifungal rezafungin during IAC.

Methods:

We createdΔMSH2 in BG2 using SAT-Flipper, and tested virulence and rezafungin responses in a mouse model of IAC.

Results:

ΔMSH2 displayed no growth defects at 30°C in liquid (YPD, Ypglycerol) or solid media (YPD+0.02% MMS, 1MM H2O2, 1M NACL, 20 UG/ML CW, 250 UG/ML OR 0.02% SDS). ΔMSH2 longevity in YPD was comparable to BG2. Caspofungin-, Rezafungin- and Fluconazole-resistant mutants arose 24-, 16- and 3-fold more often, respectively, for ΔMSH2 than BG2 (108-106 CFU overnight in YPD, selected on 8XMIC-Containing plates). However, respective minimum inhibitory concentrations (MICS) were not different, nor were rezafungin time-kills.ΔMSH2 was comparable to BG2 in peritonitis and abscess burdens in mouse IAC.ΔMSH2 demonstrated significantly greater caspofungin- and fluconazole-tolerance than BG2 in abscesses. Rezafungin reduced peritonitis and abscess burdens ofΔMSH2,BG2 ANDFKS mutant strains to similar extents.

Conclusions:

CgMSH2 deletionincreased the frequency of spontaneously-arising echinocandin- and fluconazole-resistant colonies in vitro and tolerance in intra-abdominal abscesses, but it did not attenuate virulence or rezafungin responses during IAC.
The microbial ecology of Candida albicans strains CHN1 and SC5314 in mice
Authors: Bazzi Malak , Nawrocki Katie , Brown Christopher , Falkowski Nicole , Stark Kelsey , Huffnagle Gary
Published: December 2021

Strain SC5314 is the most widely studied strain of Candida albicans. Despite C. albicans being the most commonly isolated yeast from the human gastrointestinal (GI) microbiome, strain SC5314 does not stably colonize the mouse GI tract long term, even after antibiotic disruption. In contrast, strain CHN1 will stably colonize the mouse GI tract long term. Comparative genomic analysis of strain CHN1 indicates that it belongs to a different evolutionary clade of C. albicans than strain SC5314. Previous studies from our laboratory have shown that colonization by strain CHN1 causes a change in the GI bacterial microbiome of mice and predisposes them to more robust Th2 immune responses. Despite this, little is known about the GI microbial ecology of SC5314 vs. CHN1 and subsequent host responses. Using a short-term antibiotic disruption model in C57BL/6 mice, we have been able to observe significantly different colonization kinetics between these two C. albicans strains, with CHN1 establishing stable long-term colonization. In contrast, colonization by SC5314 was lower, highly variable and cage-dependent. C. albicans colonization kinetics impacted the composition of the bacterial microbiome with a marked effect on the levels of Lactobacillus and Enterococcus. qPCR analysis of 46 host immune response genes did not detect significant differences in host gene expression between SC5134 and CHN1 colonized mice, except for chitinase expression. Thus, these studies suggest that yeast-bacteria interactions in the microbiome may be far more important in determining long-term colonization potential of C. albicans and secondary immunomodulatory effects.
A variant ECE1 allele contributes to reduced pathogenicity of Candida albicans during vulvovaginal candidiasis via altered secretion of candidalysin
Authors: Liu Junyan , Sansevere Emily , Barker Katherine , Willems Hubertine , Lowes David , Peters Brian
Published: December 2021

Background:

Candida albicans is the primary etiological agent of vulvovaginal candidiasis (VVC) and exerts its pathogenicity through secretion of the peptide toxin candidalysin encoded by the ECE1 gene. A highly conserved variant ECE1 sequence exists across a diverse set of clinical isolates. Thus, we sought to determine the relative pathogenicity and mechanism(s) associated with this alternative ECE1 allele.

Methods:

Isogenic strains harboring WT or variant ECE1 sequences were engineered in an Δ/Δece1 background. After confirmation of equivalent expression by qPCR, pathogenicity of strains were tested using in vitro epithelial cell and in vivo VVC models of infection and LDH, IL-1β, neutrophil levels monitored. Follow up studies using synthetic candidalysin peptide were also performed. Lastly, a panel of ECE1 chimeras were constructed to assess potential processing defects and detected by a novel HiBiT-tagging approach.

Results:

Strains transformed with either the variant full length ECE1 or candidalysin allele, as compared to the WT sequence, demonstrated significantly reduced immunopathogenicity during in vitro or in vivo infection despite equivalent fungal burden. Interestingly, epithelial challenge with WT or variant synthetic peptide revealed similar capacity to elicit damage and IL-1β. Allele profiling and ECE1 chimera experiments demonstrated that defects in pathogenicity are at least partly due to inefficient ECE1 processing at the peptide 2-peptide 3 junction.

Discussion:

The ECE1 gene displays conserved polymorphisms that alter candidalysin secretion and strain pathogenicity. Future work is focused on determining specific amino acid sequences that contribute to these affects across clinical isolates and disease states.
Preliminary study into the effects of tobacco smoke on Candida albicans
Authors: Williams Megan , Edwards Siôn , Fallis Ian , Wilson Melanie , Bradshaw David , Williams David W
Published: December 2021

Background:

Denture-stomatitis (DS) is the most common form of oral candidosis with increased prevalence in cigarette smokers (Akram et al. 2018). Interestingly, tobacco condensate (TC) increases Candida albicans adhesion, growth, biofilm-formation, virulence gene expression (Semlali et al. 2014)and hyphal production (Awad and Karuppayil 2018). We hypothesised that TC-treated denture acrylic would therefore affect C. albicans within acrylic biofilms.

Methods:

Acrylic discs (pre-conditioned with TC, artificial saliva (AS) or water) were incubated at 37°C with C. albicans (n=6) for 90 min or 24 h. Adherent Candida were stained with calcofluor white and confocal laser scanning microscopy (CLSM) used to assess levels of adherence, biofilm and hyphal numbers. Expressed virulence genes (n=7) were measured by qPCR.

Results:

CLSM showed that effects of TC-treatment were strain dependent. Adherence of C. albicans PTR/94 to TC-treated surfaces was significantly (P<0.002) lower than on the untreated control. Biofilm levels of PTR/94 after 24 h were found to be significantly higher on AS-treated acrylic than the TC-treated and untreated control. Five strains had significantly fewer filamentous forms after 90 min on TC-treated surfaces. TC-treatment promoted hyphal levels for strain 705/93 after 24h.

Conclusion:

TC pre-conditioning altered adherence and biofilm coverage of C. albicans to acrylic surfaces and influenced hyphal development. Work is ongoing to ascertain the significance of these effects on C. albicans pathogenicity.

Akram et al. (2018). Journal of Oral Science 60(1):115–120.

Awad and Karuppayil (2018). American Journal of Clinical Microbiology and Antimicrobials1(3):1–6.

Semlali et al. (2014). BMC Microbiology. 14:61
Evaluation of antifungal activity of Terminalia subspathulata bark and fruit extracts against azole-resistant Candida isolates
Authors: Yahaya Hassan , Abdullahi Sharif Alhassan , Yakubu Yahaya
Published: December 2021

Background:

Emerging resistant Candida species become a severe problem for public health. The study aims to examine the efficacy of Terminalia subspathulata bark and fruit extracts as an alternative source of antifungals for resistant strains of Candida species.

Methodology:

Candida albicans was isolated between 4–5th interdigital foot space and C. parapsilosis were isolated from the left-hand third finger of male patients. Morphological and molecular methods identified the isolates. Antifungal susceptibility testing (AFST) was determined using azole derivatives, amphotericin B (AmpB) and echinocandins based on E-test and broth microdilution (BMD) methods. The AFST activity of the 10 μL methanolic extracts with concentrations between 1.25–10 mg/mL was assessed by disk diffusion method according to CLSI guidelines.

Results:

The AFST results showed total resistance to all azoles (FLU, MIC ≥ 256 μg/ml and VOR, ITR and POS each with MIC ≥ 32 μg/ml). The BMD method agreed with E-test MICs. The T. subspathulata bark extract tested indicated activity on the C. albicans lawn with the zone of inhibition between 9–13 mm. The fruit extract indicated zone between 8–10 mm. Candida parapsilosis indicated susceptibility to bark extract with the zone of inhibition between 10–15 mm, while the fruit extract showed zone between 8–13 mm.

Conclusion:

Despite azole resistance, the extracts showed good activity against the isolates. Findings showed alternatives to AmpB and echinocandins because of toxicity and parenteral administration, respectively. Based on our findings, our study first reports the medicinal value of T. subspathulata.
Characterization of the mechanism of action of the Enterococcus faecalis bacteriocin EntV on Candida albicans
Authors: Buda De Cesare Giuseppe , Chebaro Yasmin , Guha Shantanu , Cruz Melissa , Garsin Danielle , Lorenz Michael
Published: December 2021

Candida albicans shares communal niches with multiple bacterial species. Previous work from our group demonstrated that the Gram-positive bacterium Enterococcus faecalis, a normal constituent of the oral and gut microbiome that is often co-isolated with C. albicans, antagonizes hyphal morphogenesis, biofilm formation, and virulence in C. albicans. These effects are mediated by EntV, a bacteriocin and antimicrobial peptide produced by E. faecalis. The main aim of this work is to unveil the molecular mechanism behind the activity of EntV on C. albicans. Using fluorescence microscopy, we determined that EntV binds to the cell walls of several Candida species, including both yeast and hyphae of C. albicans. Contrary to other antimicrobial peptides, it does not cause cell lysis and does not synergize with cell wall damaging agents. Moreover, we screened a library of C. albicans mutants for strains with altered susceptibility to the peptide; most of the positive hits had functions related to cell wall maintenance and were further screened to ascertain changes in the staining patterns. Furthermore, to identify the target layer on the cell wall, pull-down assays were performed. Mannan was identified as the major wall component able to bind the peptide. Finally, live imaging of macrophages incubated with Candida was carried out in order to assess any change in the phagocytic behaviour in presence of the peptide. Identifying the molecular target of EntV in regard to the anti-virulence mechanisms of C. albicans is an important step in its further development as a therapeutic addition to the classical antifungal agents.
Short peptides derived from EntV inhibit virulence and biofilm formation in Candida albicans
Authors: Cristy Shane , Garsin Danielle , Lorenz Michael
Published: December 2021

Candida albicans exists as a member of the commensal flora of the skin and gut where many complex polymicrobial interactions occur with genera such as Pseudomonas, Staphylococcus, and Streptococcus. Some of these interactions potentiate or inhibit virulence. The bacterial gastrointestinal commensal speciesEnterococcus faecalisproduces a small peptide, EntV, that modulates C. albicans virulence. The active 68 amino acid EntV peptide inhibits biofilm formationin vitro; biofilm-related infections are difficult to treat with current therapeutics. EntV also attenuates fungal virulence in a Caenorhabditis elegansinfection model and a murine oral candidiasis model. We sought to identify the regions of EntV responsible for the anti-fungal activity, and based on structural information, we hypothesized that it could be localized to a single helix of the mature peptide. In this study, we report that smaller peptides derived from this helix ranging from 12 to 16 amino acids have equal to improved efficacy in inhibiting C. albicans virulence andbiofilm formation. These smaller peptides attenuate virulence in the C. elegans infection model, inhibit initial adhesion to abiotic surfaces, and reduce the size of mature biofilms measured by confocal microscopy. Further trimming of these peptides to fewer than 11 amino acids reduces and eventually eliminates activity. These data indicate that EntV-derived peptides warrant further investigation as potential non-fungicidal additives to medical devices and antifungal therapeutics.
The gut commensal Bacteroides vulgatus mpk reduces Candida albicans pathogenicity towards epithelial cells
Authors: Hammer Merle Lisa , Niemiec Maria Joanna , Auge Isabel , van Leeuwen Pim , Gorki Friederike , Steimle Alexander , Frick Julia-Stefanie , Denise Jacobsen Ilse
Published: December 2021

The human body is colonized by various microbes, among them the yeast Candida albicans. Mostly harmless, this opportunist causes also disease, ranging from superficial infections to sepsis. Risk factors are disturbed host defenses, mucosal barrier breakdown, and antibiotic-induced dysbiosis. Hence, residing bacteria are important to protect from Candida-mediated damage or inflammation. Bacteroides vulgatus mpk, e.g., is described as positively immunomodulatory in mouse models of inflammatory bowel disease, but its effect on the mycobiota is unknown.

In this study we aimed to determine if B. vulgatus mpk affects C. albicans pathogenicity.

Therefore, intestinal and oral epithelial cellswere pre-infectedin vitrowith B. vulgatus mpk and then challenged with C. albicans SC5314. The role of soluble factors was investigated by spatial separation or use of Bacteroides-conditioned medium (BCM).

Preincubation of host cells with B. vulgatus mpk strongly reduced C. albicans-mediated damage while fungal burden and hyphal length were unaffected by the bacterium. The protective effect did not depend on direct contact of Bacteroidesto host cellsor Candida and could be mimicked using BCM. Contact independency suggests that diffusible factors modulate host cell susceptibility.

Ongoing experiments aim to identifykey soluble Bacteroides mediators as well as subsequent host cell signaling. Additionally, co-colonization experiments of germ-free mice are planned to investigate B. vulgatus mpk’s potential to mediate colonization resistance towards C. albicans. This will contribute to our understanding of how commensal bacteria affect C. albicans and host protection.
Enrichment analysis on regulatory subspaces: a novel direction for the superior description of cellular responses to SARS-CoV-2
Authors: Rodrigues Pedro , Costa Rafael S. , Henriques Rui
Published: December 2021

Statement

The enrichment analysis of discriminative cell transcriptional responses to SARS-CoV-2 infection using biclustering produces a broader set of superiorly enriched GO terms and KEGG pathways against alternative state-of-the-art machine learning approaches, unraveling novel knowledge.

Motivation and methods

The comprehensive understanding of the impacts of the SARS-CoV-2 virus on infected cells is still incomplete. This work identifies and analyses the main cell regulatory processes affected and induced by SARS-CoV-2, using transcriptomic data from several infectable cell lines available in public databases and in vivo samples. We propose a new class of statistical models to handle three major challenges, namely the scarcity of observations, the high dimensionality of the data, and the complexity of the interactions between genes. Additionally, we analyse the function of these genes and their interactions within cells to compare them to ones affected by IAV (H1N1), RSV and HPIV3 in the target cell lines.

Results

Gathered results show that, although clustering and predictive algorithms aid classic functional enrichment analysis, recent pattern-based biclustering algorithms significantly improve the number and quality of the detected biological processes. Additionally, a comparative analysis of these processes is performed to identify potential pathophysiological characteristics of COVID-19. These are further compared to those identified by other authors for the same virus as well as related ones such as SARS-CoV-1. This approach is particularly relevant due to a lack of other works utilizing more complex machine learning tools within this context.
White Matter β-Amyloid Precursor Protein Immunoreactivity in Autopsied Subjects With and Without COVID-19
Authors: Beach Thomas G. , DeTure Michael , Walker Jessica E. , Arce Richard , Glass Michael J. , Sue Lucia I. , Intorcia Anthony J. , Nelson Courtney M. , Suszczewicz Katsuko E. , Borja Claryssa I. , Serrano Geidy E. , Dickson Dennis W.
Published: December 2021

The coronavirus SARS-CoV-2 causes COVID-19, a predominantly respiratory disease that has been reported to be associated with numerous neurological signs, symptoms and syndromes. More than 20 published studies have used RT-PCR methods to determine viral SARS-CoV-2 genomic presence in postmortem brain tissue and the overall impression is that viral brain invasion is relatively uncommon and occurs in low copy numbers, supporting indirect mechanisms as the cause of most neurological phenomena. Hypoxic-ischemic brain injury and stroke are one such possible indirect mechanism, as acute ischemia or stroke concurrence with COVID-19 has been reported as being 0.5% to 20%. Immunohistochemical stains for β-amyloid precursor protein (APP) have been suggested to be a “signature” change of hypoxic leukoencephalopathy or COVID-19 brain disease, although prior reports have not had a non-COVID-19 control group. We therefore compared the prevalence and intensity of white matter APP staining in the brains of subjects dying with and without COVID-19. Clinical and neuropathological results, including semi-quantitative assessment of the density of white matter APP staining, were compared between 20 COVID-19 cases and 20 pre-COVID-19 autopsy cases, including 10 cases with autopsy-proven non-COVID-19 pneumonia and 10 cases without pneumonia. Positive APP white matter staining in at least one of the two brain regions (precentral gyrus and cingulate gyrus) studied was not significantly more common in COVID-19 vs controls (14/20 vs 12/20). Comparing density scores from both brain regions combined, the mean scores for COVID-19 cases were higher than those for controls of both types together but not significantly different when restricting to controls with pneumonia. Among control cases, cases with pneumonia had significantly higher scores. The presence or absence of a major neuropathologically-defined neurodegenerative disorder did not significantly affect the APP scores. The major finding is that while APP white matter staining cannot be regarded as a specific marker of COVID-19, as it does not occur with significantly greater probability in in COVID-19 brains as compared to non-COVID-19 brains, it is possible that white matter APP staining, representing acute or subacute axonal damage, may be a common occurrence in the perimortem period, and that it may be more intense in subjects dying with pneumonia, regardless of cause.
NFL COVID-19 Return to Sport Injury Prevalence Comparison
Authors: Puga Troy , Schafer Josh , Agbedanu Prince , Treffer Kevin
Published: December 2021

1.

Purpose

During the COVID 19 Pandemic, the NFL teams have been reported to have limited training sections in preparation for their games. This study compares the prevalence of injury during the 2018, 2019, and 2020 NFL seasons, with the aim to determine the potential causes of the differences in prevalence.

2.

Method

Official injury reports from each team were counted during the 17-week regular season of each year (2018, 2019, and 2020). The data was analyzed using an unpaired t-test to compare the injury prevalence between each of the three seasons.

3.

Results

The 2018 season produced a total of 1,561 injuries and a mean of 48.78 injuries per team. The 2019 season produced a total of 1,897 injuries and mean of 59.28 injuries per team, while the 2020 season produced a total of 2, 484 injuries and mean of 77.63 injuries per team. An unpaired t-test was performed using the data to compare the mean number of injuries per team of each of the seasons. Comparison of the 2020 season against the 2019 season showed a statistically significant difference (P=.0003). Comparison of the 2020 season to the 2018 season found a statistically significant difference (P=.0001). Comparison between the 2019 and the 2018 seasons found a statistically significant difference (P=.0314).

Conclusion

Although the 2019 and 2018 season showed a statistically significant difference (P=0.0314), this difference is not as astronomical when we compare the 2020 seasons vs 2019 and 2018 seasons (P=0.0003 and P=0.0001, respectively) (Figure 2). The astronomical increase in injury prevalence in the 2020 season over the previous years does raise the possibility that there was reduced physiological adaption to stress, due to the limited amount of training embarked on. The limited amount of training was the result of closure of practice facilities during the COVID-19 pandemic. More physiological investigation involving players must be done at the professional and amateur levels to determine if there is a lack of physiological adaptation due to limited use of practice and training facilities during the COVID-19 pandemic.
Identifying weather variables as important clinical predictors of bacterial diarrhea among international travelers to Nepal and Thailand
Authors: Pender Melissa A. , Smith Timothy , Brintz Ben J. , Pandey Prativa , Shrestha Sanjaya , Anuras Sinn , Demons Samandra , Sornsakrin Siriporn , Platts-Mills James A. , Bodhidatta Ladaporn , Leung Daniel T.
Published: December 2021

Background

Clinicians and travelers often have limited tools to differentiate bacterial from non-bacterial causes of travelers’ diarrhea (TD). Development of a clinical prediction rule assessing the etiology of TD may help identify episodes of bacterial diarrhea and limit inappropriate antibiotic use. We aimed to identify predictors of bacterial diarrhea among clinical, demographic, and weather variables, as well as to develop and cross-validate a parsimonious predictive model.

Methods

We collected de-identified clinical data from 457 international travelers with acute diarrhea presenting to two healthcare centers in Nepal and Thailand. We used conventional microbiologic and multiplex molecular methods to identify diarrheal etiology from stool samples. We used random forest and logistic regression to determine predictors of bacterial diarrhea.

Results

We identified 195 cases of bacterial etiology, 63 viral, 125 mixed pathogens, 6 protozoal/parasite, and 68 cases without a detected pathogen. Random forest regression indicated that the strongest predictors of bacterial over viral or non-detected etiologies were average location-specific environmental temperature and RBC on stool microscopy. In 5-fold cross-validation, the parsimonious model with the highest discriminative performance had an AUC of 0.73 using 3 variables with calibration intercept -0.01 (SD 0.31) and slope 0.95 (SD 0.36).

Conclusions

We identified environmental temperature, a location-specific parameter, as an important predictor of bacterial TD, among traditional patient-specific parameters predictive of etiology. Future work includes further validation and the development of a clinical decision-support tool to inform appropriate use of antibiotics in TD.
Role of immigrant males and muzzle contacts in the uptake of a novel food by wild vervet monkeys
Authors: Dongre Pooja , Lanté Gaëlle , Cantat Mathieu , Canteloup Charlotte , van de Waal Erica
Published: December 2021

The entry into and uptake of information in social groups is critical for behavioural adaptation by long-lived species in rapidly changing environments. We exposed five groups of wild vervet monkeys to a novel food to investigate innovation of processing and consuming it. We report that immigrant males innovated in two groups, and an infant innovated in one group. In two other groups, immigrant males imported the innovation from their previous groups. We compared uptake between groups with respect to the initial innovator to examine the extent to which dispersing males could introduce an innovation into groups. Uptake of the novel food was faster in groups where immigrant males ate first rather than the infant. Younger individuals were more likely overall, and faster, to subsequently acquire the novel food. We also investigated the role of muzzle contact behaviour in information seeking around the novel food. Muzzle contacts decreased in frequency over repeated exposures to the novel food. Muzzle contacts were initiated the most by naïve individuals, high rankers and juveniles; and were targeted most towards knowledgeable individuals and high rankers, and the least towards infants. We highlight the potential importance of dispersers in rapidly exploiting novel resources among populations.
Long term exposure of human gut microbiota with high and low emulsifier sensitivity to soy lecithin in M-SHIME model
Authors: Miclotte Lisa , De Paepe Ellen , Li Qiqiong , Van Camp John , Rajkovic Andreja , Van de Wiele Tom
Published: December 2021

In the context of the potential health hazards related to food processing, dietary emulsifiers have been shown to alter the structure and function of the gut microbial community, both in vivo and in vitro. In mouse models, these emulsifier exposed gut microbiota were shown to contribute to gut inflammation. Several knowledge gaps remain to be addressed though. As such, the impact from a longer timeframe of exposure on the gut microbiota is not known and interindividual variability in microbiome response needs to be measured.

To answer these research questions, in this study the faecal microbiota from two individuals, previously selected for high and low emulsifier sensitivity, were exposed to two concentrations of soy lecithin during a 7 day treatment phase in the dynamic mucosal simulator of the human intestinal microbial ecosystem (M-SHIME). The results showed mild effects from soy lecithin on the composition and functionality of these microbial communities, which depended on the original microbial composition. The effects also mostly levelled off after 3 days of exposure. The emulsifier sensitivity for which the microbiota were selected, was preserved. Some potentially concerning effects were also registered: butyrate levels, positively correlating with Faecalibacterium abundance, were lowered by soy lecithin. Also the abundance of the beneficial Bifidobacterium genus was lowered, while the abundance of the notorious unclassified Enterobacteriaceae was increased. Within the family of the unclassified Lachnospiraceae, several genera were either suppressed or stimulated.

The effects that these microbial alterations would have on a living host is not yet certain, especially given the fact that large fractions of soy lecithin’s constituents can be absorbed. Nevertheless, choline and phosphatidylcholine, both primary and absorbable constituents of soy lecithin, have recently been linked to cardiovascular disease via the generation of TMA by the gut microbiota. Further studies that validate our findings and link them to potential health outcomes are thus justified.
A seasonal pulse of ungulate neonates influences space use by carnivores in a multi-predator, multi-prey system
Authors: Ruprecht Joel , Forrester Tavis D. , Jackson Nathan J. , Clark Darren A. , Wisdom Michael J. , Rowland Mary M. , Smith Joshua B. , Stewart Kelley M. , Levi Taal
Published: December 2021

The behavioral mechanisms by which predators encounter prey are poorly resolved. In particular, the extent to which predators engage in active search for prey versus incidentally encountering them is unknown. The distinction between search and incidental encounter influences prey population dynamics with active search exerting a stabilizing force on prey populations by alleviating predation pressure on low-density prey and increasing it for high-density prey.

Parturition of many large herbivores occurs during a short and predictable temporal window in which young are highly vulnerable to predation. Our study aims to determine how a suite of carnivores responds to the seasonal pulse of newborn ungulates using contemporaneous GPS locations of four species of predators and two species of prey.

We used step-selection functions to assess whether coyotes, cougars, black bears, and bobcats actively searched for parturient females in a low-density population of mule deer and a high-density population of elk. We then assessed whether searching carnivores shifted their habitat use toward areas exhibiting a high probability of encountering neonates.

None of the four carnivore species encountered parturient mule deer more often than expected by chance suggesting that predation of young resulted from incidental encounters. By contrast, we determined that cougar and male bear movements positioned them in proximity of parturient elk more often than expected by chance which is evidence of searching behavior. Although both male bears and cougars searched for neonates, only male bears used elk parturition habitat in a way that dynamically tracked the phenology of the elk birth pulse suggesting that maximizing encounters with juvenile elk was a motivation when selecting resources.

Our results support the existence of a stabilizing mechanism to prey populations through active search behavior by predators because carnivores in our study searched for the high-density prey species (elk) but ignored the low-density species (mule deer). We conclude that prey density must be high enough to warrant active search, and that there is high interspecific and intersexual variability in foraging strategies among large mammalian predators and their prey.
Aberrant Fucosylation of Saliva Glycoprotein Defining Lung Adenocarcinomas Malignancy
Authors: Gao Ziyuan , Wu Zhen , Han Ying , Zhang Xumin , Hao Piliang , Xu Mingming , Huang Shan , Li Shuwei , Xia Jun , Jiang Junhong , Yang Shuang
Published: December 2021

Aberrant glycosylation is a hallmark of cancer found during tumorigenesis and tumor progression. Lung cancer induced by oncogene mutations has been detected in the patient’s saliva, and saliva glycosylation has been altered. Saliva contains highly glycosylated glycoproteins, the characteristics of which may be related to various diseases. Therefore, elucidating cancer-specific glycosylation in the saliva of healthy, non-cancer, and cancer patients can reveal whether tumor glycosylation has unique characteristics for early diagnosis. In this work, we used a solid-phase chemoenzymatic method to study the glycosylation of saliva glycoproteins in clinical specimens. The results showed that the α1,6-core fucosylation of glycoproteins in cancer patients was significant increased. The fucosylation of α1,2 or α1,3 is also increased in cancer patients. We further analyzed the expression of fucosyltransferases responsible for α1,2, α1,3, α1,6 fucosylation. The fucosylation of the saliva of cancer patients is drastically different from that of non-cancer or health controls. These results indicate that the glycoform of saliva fucosylation distinguishes lung cancer from other diseases, and this feature has the potential to diagnose lung adenocarcinoma.

TOC

Fucosylation biosynthesis in lung cancer. Saliva fucosylation contains α1,2-linked, α1,3-linked, α1,6-linked fucosylation in lung cancer.
Predicting biomass of resident kōkopu (Galaxias) populations using local habitat composition
Authors: Crichton Ben R. J. , Hickford Michael J.H. , McIntosh Angus R. , Schiel David R.
Published: December 2021

With the global decline of freshwater fishes, quantifying the body size-specific habitat use of vulnerable species is crucial for accurately evaluating population health, identifying the effects of anthropogenic stressors, and directing effective habitat restoration. Populations of New Zealand’s endemic kōkopu species (Galaxias fasciatus, G. argenteus, and G. postvectis) have declined substantially over the last century in response to anthropogenic stressors, including habitat loss and fragmentation, invasive species, and over-exploitation. Despite well-understood habitat associations, key within-habitat features driving the reach-scale biomass of small and large kōkopu remain unclear. Here, we investigated whether the total biomass of small (≤ 90 mm) and large (> 90 mm) kōkopu was associated with total pool area, average pool depth, total bank cover, average substrate size, and average forest canopy cover across fifty-seven 50 m reaches. These features were selected because generally pool habitats are productive feeding areas, bank cover and substrate interstices are important refuges, and forest cover provides greater food availability. Because kōkopu are nocturnal, populations were sampled with removal at night using headlamps and hand-nets until reaches were visually depleted. Using Akaike’s information criterion, it was found that increases in large kōkopu biomass were most parsimoniously explained by greater pool area and bank cover, whereas increases in small kōkopu biomass were best explained by low bank cover and greater average forest cover. This study demonstrated the importance of considering the ontogenetic shift in species’ habitat use and provided an effective modelling approach for quantifying the size-specific habitat use of these stream-dwelling fish.
Reconstructing mitochondrial genomes from ancient DNA through iterative mapping: an evaluation of software, parameters, and bait reference
Authors: Westbury Michael V. , Lorenzen Eline D.
Published: December 2021

Within evolutionary biology, mitochondrial genomes (mitogenomes) provide useful insights at both population and species level. Several approaches are available to assemble mitogenomes. However, most are not suitable for divergent, extinct species, due to the requirement of a reference mitogenome from a conspecific or close relative, and relatively high-quality DNA.

Iterative mapping can overcome the lack of a close reference sequence, and has been applied to an array of extinct species. Despite its widespread use, the accuracy of the reconstructed assemblies are yet to be comprehensively assessed. Here, we investigated the influence of mapping software (BWA or MITObim), parameters, and bait reference phylogenetic distance on the accuracy of the reconstructed assembly using two simulated datasets: (i) spotted hyena and various mammalian bait references, and (ii) southern cassowary and various avian bait references. Specifically, we assessed the accuracy of results through pairwise distance (PWD) to the reference conspecific mitogenome, number of incorrectly inserted base pairs (bp), and total length of the reconstructed assembly.

We found large discrepancies in the accuracy of reconstructed assemblies using different mapping software, parameters, and bait references. PWD to the reference conspecific mitogenome, which reflected the level of incorrect base calls, was consistently higher with BWA than MITObim. The same was observed for the number of incorrectly inserted bp. In contrast, the total sequence length was lower. Overall, the most accurate results were obtained with MITObim using mismatch values of 3 or 5, and the phylogenetically closest bait reference sequence. Accuracy could be further improved by combining results from multiple bait references.

We present the first comprehensive investigation of how mapping software, parameters, and bait reference influence mitogenome reconstruction from ancient DNA through iterative mapping. Our study provides information on how mitogenomes are best reconstructed from divergent, short-read data. By obtaining the most accurate reconstruction possible, one can be more confident as to the reliability of downstream analyses, and the evolutionary inferences made from them.
Invasive slipper limpets Crepidula fornicata act like a sink, rather than source, of Vibrio spp.
Authors: Quinn Emma A. , Malkin Sophie H. , Thomas Jessica E. , Poole Ryan , Davies Charlotte E. , Rowley Andrew F. , Coates Christopher J.
Published: December 2021

A large knowledge gap exists regarding the disease profile and pathologic condition of the invasive, non-native, slipper limpet Crepidula fornicata. To help address this, we performed a yearlong health survey across two sites in South Wales UK – subtidal Swansea Bay and intertidal Milford Haven. In total, 1,800 limpets were screened systematically for haemolymph bacterial burdens using both general and vibrio-selective growth media (TSA +2% NaCl and TCBS, respectively), haemolymph (blood) inspection using microscopy, a PCR-based assay targeting Vibrio spp., and multi-tissue histology. Over 99% of haemolymph samples contained cultivable bacterial colony forming units, and 83% of limpets tested positive for the presence of vibrios via PCR (confirmed via Sanger sequencing). Vibrio presence did not vary greatly across sites, yet a strong temporal (seasonal) effect was observed – significantly higher bacterial loads during the summer. Binomial logistic regression models revealed larger (older) limpets were more likely to harbour vibrios, and the growth of bacteria on TCBS was a key predictor for PCR-based vibrio detection. Histological assessment of >340 animals revealed little evidence of inflammation, sepsis, or immune reactivity despite the gross bacterial numbers. We contend that slipper limpets are not susceptible to bacteriosis at either site surveyed, or do not to harbour vibrios known to be pathogenic to humans. The lack of susceptibility to local pathogenic bacteria may explain, in part, the invasion success of C. fornicata across this region.
Human Mitochondrial AAA+ ATPase SKD3/CLPB forms Nucleotide-Stabilized Dodecamers
Authors: Spaulding Zachary , Thevarajan Indhujah , Schrag Lynn G. , Zubcevic Lejla , Zolkiewska Anna , Zolkiewski Michal
Published: December 2021

SKD3, also known as human CLPB, belongs to the AAA+ family of ATPases associated with various activities. Mutations in the SKD3/CLPB gene cause 3-methylglutaconic aciduria type VII and congenital neutropenia. SKD3 is upregulated in acute myeloid leukemia, where it contributes to anti-cancer drug resistance. SKD3 resides in the mitochondrial intermembrane space, where it forms ATP-dependent high-molecular weight complexes, but its biological function and mechanistic links to the clinical phenotypes are currently unknown. Using sedimentation equilibrium and dynamic light scattering, we show that SKD3 is monomeric at low protein concentration in the absence of nucleotides, but it forms oligomers at higher protein concentration or in the presence of adenine nucleotides. The apparent molecular weight of the nucleotide-bound SKD3 is consistent with self-association of 12 monomers. Image-class analysis and averaging from negative-stain electron microscopy (EM) of SKD3 in the ATP-bound state visualized cylinder-shaped particles with an open central channel along the cylinder axis. The dimensions of the EM-visualized particle suggest that the SKD3 dodecamer is formed by association of two hexameric rings. While hexameric structure has been often observed among AAA+ ATPases, a double-hexamer sandwich found for SKD3 appears uncommon within this protein family. A functional significance of the non-canonical structure of SKD3 remains to be determined.