53 research outputs found

    Fatty Acid Synthase Impacts the Pathobiology of Candida parapsilosis In Vitro and during Mammalian Infection

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    Cytosolic fungal fatty acid synthase is composed of two subunits α and β, which are encoded by Fas1 and Fas2 genes. In this study, the Fas2 genes of the human pathogen Candida parapsilosis were deleted using a modified SAT1 flipper technique. CpFas2 was essential in media lacking exogenous fatty acids and the growth of Fas2 disruptants (Fas2 KO) was regulated by the supplementation of different long chain fatty acids, such as myristic acid (14∶0), palmitic acid (16∶0), and Tween 80, in a dose-specific manner. Lipidomic analysis revealed that Fas2 KO cells were severely restricted in production of unsaturated fatty acids. The Fas2 KO strains were unable to form normal biofilms and were more efficiently killed by murine-like macrophages, J774.16, than the wild type, heterozygous and reconstituted strains. Furthermore, Fas2 KO yeast were significantly less virulent in a systemic murine infection model. The Fas2 KO cells were also hypersensitive to human serum, and inhibition of CpFas2 in WT C. parapsilosis by cerulenin significantly decreased fungal growth in human serum. This study demonstrates that CpFas2 is essential for C. parapsilosis growth in the absence of exogenous fatty acids, is involved in unsaturated fatty acid production, influences fungal virulence, and represents a promising antifungal drug target

    Concussion-reporting behavior in rugby: A national survey of rugby union players in the United States

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    Background: Rugby is the fastest growing team sport in the United States for male and female athletes. It is a contact/collision sport with an injury risk profile that includes concussions. Purpose: To examine the prevalence of concussions in male and female rugby players in the United States and to characterize behaviors around reporting concussions that could be a target for prevention and treatment efforts. Study Design: Cross-sectional study; Level of evidence, 3. Methods: An online survey distributed to active members on the USA Rugby membership list was used to examine self-reported concussions in male and female athletes. Concussion-reporting behaviors and return to play after a concussion were also explored. Statistical analysis was used to compare male with female athletes and report differences, with years of experience as a dependent variable. Results: The proportion of athletes with a history of at least 1 concussion was 61.9% in all respondents. Of those who reported a concussion, 50.8% reported the concussion during the game or practice in which it occurred, and 57.6% reported at least 1 concussion to a qualified medical provider. Overall, 27.7% of participants who reported ≥1 rugby-related concussion in our survey noted that at least 1 of these concussions was not formally reported. The most commonly cited reasons for not reporting a concussion included not thinking that it was a serious injury, not knowing that it was a concussion at the time, and not wanting to be pulled out of the game or practice. Additionally, 61.0% of athletes did not engage in recommended return-to-play protocols after their most recent rugby-related concussion. Conclusion: US rugby union athletes may not report concussions to medical personnel or follow return-to-play protocols guided by medical advice. This could result from a lack of education on concussion recognition and the risks associated with continued play after a concussion as well as limited access to health care. Further education efforts focusing on the identification of concussions, removal from play, and return-to-play protocols are necessary in the US rugby union population

    Safety and Immunogenicity of Different Immunization Regimens of CVD 103-HgR Live Oral Cholera Vaccine in Soldiers and Civilians in Thailand

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    Attenuated Vibrio cholerae oral vaccineCVD 103-HgR was well tolerated by 324 Thai soldiers and civilians. Most receiveda single 5 × 108 cfu dose, while 40 each receivedone or two 5 × 109 cfu doses. Vibriocidal antibody (the best correlate of immunity) seroconversion was lower in soldiers than civilians (P < .001). Increasing the vaccinedose to 5 × 109 cfu raised the geometric mean titer (P < .001).Asecond 5 × 109 cfu dose one weeklater did not notably increase seroconversions. Likelihood of seroconversionwas inverselycorrelated with baseline vibriocidal titer (P < .001). CVD 103-HgR caused seroconversion in most subjects with baseline titers ⩽1:40, including 100% of civilians after one 5 × 108 cfu dose, 79% of soldiers after one 5 × 109 cfu dose, and 45% of soldiers after one 5 × 108 cfu dose. In persons with elevatedbaseline titers, vibriocidal antibody seroconversion is not a sensitive measure of whether vaccine has boosted intestinal immunity; for such subjects,other measurements must be used. Study regimens in endemic areas should use a single 5 × 109 cfu dos

    Silicone colonization by non-Candida albicans Candida species in the presence of urine

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    Urinary tract infections (UTIs) are the most common nosocomial infections and 80 % are related to the use of urinary catheters. Furthermore, Candida species are responsible for around 15 % of UTIs and an increasing involvement of non-Candida albicans Candida (NCAC) species (e.g. Candida glabrata, Candida tropicalis and Candida parapsilosis) has been recognized. Given the fact that silicone is frequently used in the manufacture of urinary catheters, the aim of this work was to compare both the adhesion and biofilm formation on silicone of different urinary clinical isolates of NCAC species (i.e. C. glabrata, C. tropicalis and C. parapsilosis) in the presence of urine. Several clinical isolates of NCAC species recovered from patients with UTIs, together with reference strains of each species, were examined. Adhesion and biofilm formation were performed in artificial urine and the biofilm biomass was assessed by crystal violet staining. Hydrophobicity and surface charge of cells was determined by measuring contact angles and zeta potential, respectively. The number of viable cells in biofilms was determined by enumeration of c.f.u. after appropriate culture. The biofilm structure was also examined by confocal laser scanning microscopy (CLSM). The results showed that all isolates adhered to silicone in a species- and strain-dependent manner with C. parapsilosis showing the lowest and C. glabrata the highest levels of adhesion. However, these differences in adhesion abilities cannot be correlated with surface properties since all strains examined were hydrophilic and exhibited a similar zeta potential. Despite a higher number of cultivable cells being recovered after 72 h of incubation, stronger biofilm formation was not observed and CLSM showed an absence of extracellular polymeric material for all isolates examined. In summary, this work demonstrated that all tested NCAC species were able to adhere to and survive on silicone in the presence of urine. Furthermore, C. glabrata strains presented higher colonization abilities than C. tropicalis and C. parapsilosis strains, a fact that might explain the larger role of C. glabrata colonization and disseminated infections in hospitalized and catheterized patients.The authors acknowledge the Fundacao para a Ciencia e Tecnologia (FCT), Portugal, for supporting the work of S. S. through grant SFRH/BD/28341/2006 and project PDTC/1310/61112/2004. The authors are also grateful to Hospital de S Marcos, Braga, for providing clinical isolates

    Loss of C-5 Sterol Desaturase Activity Results in Increased Resistance to Azole and Echinocandin Antifungals in a Clinical Isolate of Candida parapsilosis

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    Among emerging non-albicans Candida species, Candida parapsilosis is of particular concern as a cause of nosocomial bloodstream infections in neonatal and intensive care unit patients. While fluconazole and echinocandins are considered effective treatments for such infections, recent reports of fluconazole and echinocandin resistance in C. parapsilosis indicate a growing problem. The present study describes a novel mechanism of antifungal resistance in this organism affecting susceptibility to azole and echinocandin antifungals in a clinical isolate obtained from a patient with prosthetic valve endocarditis. Transcriptome analysis indicated differential expression of several genes in the resistant isolate, including upregulation of ergosterol biosynthesis pathway genes ERG2, ERG5, ERG6, ERG11, ERG24, ERG25, and UPC2. Whole-genome sequencing revealed that the resistant isolate possessed an ERG3 mutation resulting in a G111R amino acid substitution. Sterol profiles indicated a reduction in sterol desaturase activity as a result of this mutation. Replacement of both mutant alleles in the resistant isolate with the susceptible isolate's allele restored wild-type susceptibility to all azoles and echinocandins tested. Disruption of ERG3 in the susceptible and resistant isolates resulted in a loss of sterol desaturase activity, high-level azole resistance, and an echinocandin-intermediate to -resistant phenotype. While disruption of ERG3 in C. albicans resulted in azole resistance, echinocandin MICs, while elevated, remained within the susceptible range. This work demonstrates that the G111R substitution in Erg3 is wholly responsible for the altered azole and echinocandin susceptibilities observed in this C. parapsilosis isolate and is the first report of an ERG3 mutation influencing susceptibility to the echinocandins

    Candida parapsilosis, an Emerging Fungal Pathogen

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    Summary: Candida parapsilosis is an emerging major human pathogen that has dramatically increased in significance and prevalence over the past 2 decades, such that C. parapsilosis is now one of the leading causes of invasive candidal disease. Individuals at the highest risk for severe infection include neonates and patients in intensive care units. C. parapsilosis infections are especially associated with hyperalimentation solutions, prosthetic devices, and indwelling catheters, as well as the nosocomial spread of disease through the hands of health care workers. Factors involved in disease pathogenesis include the secretion of hydrolytic enzymes, adhesion to prosthetics, and biofilm formation. New molecular genetic tools are providing additional and much-needed information regarding C. parapsilosis virulence. The emerging information will provide a deeper understanding of C. parapsilosis pathogenesis and facilitate the development of new therapeutic approaches for treating C. parapsilosis infections

    The Current Utilization of Patient-reported Outcome Measurement Information System in Shoulder, Elbow, and Sports Medicine

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    Clinical research using patient-reported outcome measures has been critical within the field of shoulder, elbow, and sports medicine in helping clinicians deliver evidence-based and value-based medicine. Recently, however, clinicians have advocated for improving the process of obtaining clinically meaningful information from patients while decreasing survey fatigue and increasing compliance. To that end, the National Institutes of Health created the Patient-Reported Outcome Measures Information System (PROMIS) in which a number of institutions and research investigations have adopted for reporting outcomes. A special focus has also been placed on PROMIS Computer Adaptive Testing forms, which tailor questioning through item response theory. The purpose of this study was to provide insight into the utilization, advantages, and disadvantages of PROMIS within the field of shoulder, elbow, and sports medicine and provide a comparison with legacy patient-reported outcome measure measurements

    Evidence Versus Practice: Operative Treatment Preferences in Hallux Valgus

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    Background: There is substantial variability in the operative treatment of hallux valgus despite the existence of high quality evidence to guide treatment decisions. The purpose of this study was to determine the current trends in the treatment of mild, moderate, and severe hallux valgus and if greater degrees of consensus correlate with the presence of higher-level evidence. Methods: Members of the American Orthopaedic Foot & Ankle Society completed a 14-item survey. A total of 131 (14%) of 922 members completed the survey. Three cases representing 3 stages of HV were presented, and respondents selected their preferred treatment. Preferred forms of proximal and distal metatarsal osteotomies, as well as mode of fixation for each, were inquired. Results: In the treatment of mild hallux valgus without second metatarsalgia, 80% of those surveyed chose a distal metatarsal osteotomy, while, if second metatarsalgia was present, 56% chose a distal metatarsal osteotomy with a second metatarsal-shortening osteotomy. In the treatment of moderate hallux valgus, there was generally less consensus, while, in the treatment of severe hallux valgus, a majority of those surveyed chose a Lapidus procedure, with the addition of a second metatarsal-shortening osteotomy in the presence of second metatarsalgia. The most popular distal and proximal metatarsal osteotomies, respectively, were chevron osteotomy (80%) and opening wedge osteotomy (33%). The presence of Level I evidence did not significantly correlate with higher degrees of consensus. Conclusion: Despite the existence of high-quality evidence supporting the use of certain procedures in the treatment of HV, there exists an apparent lack of consensus among surgeons about the choice of surgical procedures. Moreover, higher-level evidence was not correlated with greater consensus in hallux valgus. Level of Evidence: Level II

    Disruption of Fas2 genes in <i>C. parapsilosis</i>.

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    <p>Schematic representation of disruption construct (A), genotype of wild type with Fas2 loci (B), disrupted locus with SAT1 cassette (C), and disrupted locus without SAT1 cassette (D). Southern blot analysis of wild type strain (lane1, genotype of B/B), heterozygous resistant strains (lane 2, genotype B/C), heterozygous non-resistant strain (lane 3, genotype B/D), homozygous resistant strain (lane 4, genotype C/D), homozygous non-resistant strain (lane 5, genotype D/D), and reconstituted strain (lane 6, genotype B/D). Southern blot probe was PCR amplified from the upstream fragment of plasmid pSFS2Fas2.</p
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