7 research outputs found
Recommended from our members
Identification and characterization of a Yersinia pestis insecticidal-like toxin complex
Plague, or the Black Death, is a zoonotic disease that is spread from mammal to mammal by fleas. This mode of transmission demands that the causative agent of this disease, Yersinia pestis, be able to circumvent the host defense systems of both mammals and insects. In recent years the complete genome sequence of a number of Y. pestis strains have been determined. This sequence information indicates that Y. pestis contains a cluster of genes with homology to insecticidal toxin encoding genes of the insect pathogen Photorhabdus luminescens. Here we demonstrate that Y. pestis KIM strains transcribe these insecticidal-like toxin genes, and produce the encoded proteins. Production of the locus-encoded proteins was dependent on the presence of a gene (yitR) encoding a member of the LysR family of transcriptional activators. A large complex that contains each locus-encoded protein (YitA, B, C, and YipA and B) was isolated from Y. pestis, however biological activity of this complex has not been demonstrated. The insecticidal-like toxins were secreted by the virulence plasmid-encoded type III secretion system in a calcium and temperature dependent manner. Translocation of one protein that is a putative tyrosine phosphatase, YipB, was demonstrated into both mammalian macrophage and insect cells. In conclusion, a new class of Y. pestis type three secreted and translocated proteins has been identified. We hypothesize that these proteins function to promote transmission of and infection by Y. pestis
148 Rate of Antibiotics Prescribed for Patients With Acute Diarrheal Illness and a Positive Stool Test in Immunosuppressed Versus Non-Immunosuppressed Patients
Recommended from our members
Assessing a standardized decision-making algorithm for blood culture collection in the intensive care unit.
PURPOSE: Blood cultures are commonly ordered for patients with low risk of bacteremia. Indications for obtaining blood cultures are often broad and ill defined, and decision algorithms for appropriate blood cultures have not been comprehensively evaluated in critically-ill populations. METHODS: We conducted a retrospective analysis to assess the frequency of inappropriate blood cultures in the ICUs at Montefiore Medical Center based on an evidence-based guidance algorithm. Blood cultures were reviewed against this algorithm to determine their appropriateness. We calculated the prevalence of inappropriate blood culture and explored the reasons for these collected cultures. RESULTS: 300 patients were randomly selected from an initial cohort of 3370 patients. 294 patients were included and of these, 167 patients had at least 1 blood culture drawn. 125 patients had one or more inappropriate blood culture. 61.4% of blood cultures drawn were assessed to be inappropriate. The most common reason for inappropriate cultures was a culture drawn as a result of isolated fever or leukocytosis. CONCLUSION: In a cohort of critically-ill patients, inappropriate blood cultures were common. The indications for blood cultures are often not evidence-based, and evidence-based algorithms to guide the collection of blood cultures may offer a way to decrease inappropriate culture orders
Recommended from our members
Identification and type III-dependent secretion of the Yersinia pestis insecticidal-like proteins
Bacterial and fungal coinfections in COVID-19 patients hospitalized during the New York City pandemic surge
Crystal structure of a dimeric form of streptococcal pyrogenic exotoxin A (SpeA1).
Streptococcal pyrogenic exotoxin A (SpeA1) is a bacterial superantigen associated with scarlet fever and streptococcal toxic shock syndrome (STSS). SpeA1 is found in both monomeric and dimeric forms, and previous work suggested that the dimer results from an intermolecular disulfide bond between the cysteines at positions 90 of each monomer. Here, we present the crystal structure of the dimeric form of SpeA1. The toxin crystallizes in the orthorhombic space group P212121, with two dimers in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.52% for 7248 protein atoms, 136 water molecules, and 4 zinc atoms (one zinc atom per molecule). The implications of SpeA1 dimer on MHC class II and T-cell receptor recognition are discussed
Treatment of severe COVID-19 with convalescent plasma in Bronx, NYC
Convalescent plasma with severe acute respiratory disease coronavirus 2 (SARS-CoV-2) antibodies (CCP) may hold promise as a treatment for coronavirus disease 2019 (COVID-19). We compared the mortality and clinical outcome of patients with COVID-19 who received 200 mL of CCP with a spike protein IgG titer ≥ 1:2430 (median 1:47,385) within 72 hours of admission with propensity score–matched controls cared for at a medical center in the Bronx, between April 13 and May 4, 2020. Matching criteria for controls were age, sex, body mass index, race, ethnicity, comorbidities, week of admission, oxygen requirement, D-dimer, lymphocyte counts, corticosteroid use, and anticoagulation use. There was no difference in mortality or oxygenation between CCP recipients and controls at day 28. When stratified by age, compared with matched controls, CCP recipients less than 65 years had 4-fold lower risk of mortality and 4-fold lower risk of deterioration in oxygenation or mortality at day 28. For CCP recipients, pretransfusion spike protein IgG, IgM, and IgA titers were associated with mortality at day 28 in univariate analyses. No adverse effects of CCP were observed. Our results suggest CCP may be beneficial for hospitalized patients less than 65 years, but data from controlled trials are needed to validate this finding and establish the effect of aging on CCP efficacy