Publications by authors named "Jason Yamaki"

Antimicrobial peptides (AMPs) are being explored as a potential strategy to combat antibiotic resistance due to their ability to reduce susceptibility to antibiotics. This study explored whether the [RW] peptide mode of action is bacteriostatic or bactericidal using modified two-fold serial dilution and evaluating the synergism between gentamicin and [RW] against () and methicillin-resistant (MRSA) by a checkered board assay. [RW] exhibited bactericidal activity against bacterial isolates (MBC/MIC ≤ 4), with a synergistic effect with gentamicin against (FICI = 0.

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Few studies describe the frequency of antibiotic regimen modification behaviors in the acute care setting. We sought to ascertain patient and treatment characteristics, details of regimen modification, and clinical outcomes with antibiotic modifications. This retrospective study included patients admitted to Hoag Memorial Hospital from 1 January 2019-31 March 2021 with a complicated infection caused by a Gram-negative organism resistant to extended-spectrum cephalosporins or with the potential for resistance (AmpC producers).

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Background: Fluoroquinolones are one of the most prescribed antimicrobials in the United States and have been increasingly used in inpatient and outpatient settings to treat various infectious diseases syndromes. Due to the unwanted collateral effects on antibiotic resistance, poor susceptibility rates among Gram-negative pathogens, and adverse effects, fluoroquinolones are often targeted by hospital antimicrobial stewardship programs to prevent overutilization. This study describes the association of nonrestrictive antimicrobial stewardship interventions at 2 nonacademic community hospitals on levofloxacin utilization, prescribing patterns on alternative antibiotics, and nonsusceptibility rates to levofloxacin.

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Despite the benefits of red blood cell (RBC) transfusion therapy, it can render patients vulnerable to iron overload. The excess iron deposits in various body tissues cause severe complications and organ damage such as cardiotoxicity and mold infections. infection (CDI) is the most common cause of nosocomial diarrhea among cancer patients and is associated with significant morbidity and mortality.

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The antibiogram is an essential resource for institutions to track changes in antimicrobial resistance and to guide empirical antimicrobial therapy. In this Viewpoint, data and examples from literature are presented that suggest institutions have not completely adopted the standardized approach in developing antibiograms, as variations in the development methodologies of antibiograms exist despite consensus guidelines (M39) published by CLSI. We emphasize developing antibiograms in line with the M39 recommendations will help ensure that they are accurate, reliable and valid, and highlight that understanding the limitations of antibiogram data is critical to ensuring appropriate interpretation and application to clinical decision-making.

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Vancomycin is the drug of choice for methicillin-resistant keratitis and other ocular infections. Vancomycin ophthalmic drops are not commercially available and require compounding. The present study was designed to investigate the stability of vancomycin ophthalmic drops in normal saline, phosphate-buffered saline (PBS), and balanced salt solution (BSS) while stored at room temperature or under refrigeration.

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Introduction: The severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) has infected more than 20 million people worldwide, and the spread is most prevalent in the USA, where California had accounted over 240,000 cases in the initial 5 months of the pandemic. To estimate the number of infected persons in our community, we conducted a cross-sectional study to estimate seroprevalence of SARS-CoV-2 infection.

Methods: This cross-sectional study evaluated the presence of immunoglobulin G, antibody for SARS-CoV-2 during the time period of July 15, 2020, to July 27, 2020.

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Antimicrobial peptides (AMPs) contain amphipathic structures and are derived from natural resources. AMPs have been found to be effective in treating the infections caused by antibiotic-resistant bacteria (ARB), and thus, are potential lead compounds against ARB. AMPs' physicochemical properties, such as cationic nature, amphiphilicity, and their size, will provide the opportunity to interact with membrane bilayers leading to damage and death of microorganisms.

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Hospital antimicrobial stewardship (AMS) programs are responsible for ensuring that all antimicrobials are utilized in the most appropriate and safe manner to improve patient outcomes, prevent adverse drug reactions, and prevent the development of antimicrobial resistance. This Perspectives article outlines the hospital antimicrobial use process (AUP), the foundational system that ensures that all antimicrobials are utilized in the most appropriate and safe manner. The AUP consists of the following steps: antimicrobial ordering, order verification, preparation and delivery, administration, monitoring, and discharge prescribing.

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The development of a new class of antibiotics to fight bacterial resistance is a time-consuming effort associated with high-cost and commercial risks. Thus, modification, conjugation or combination of existing antibiotics to enhance their efficacy is a suitable strategy. We have previously reported that the amphiphilic cyclic peptide [R₄W₄] had antibacterial activity with a minimum inhibitory concentration (MIC) of 2.

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It is estimated that 80% of the world population depends on traditional medicine for primary healthcare need. Trianthema portulacastrum Linn. (family: Aizoaceae) is a small perennial weed found in the Americas, Africa, India, and other regions of the world.

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Objectives: The contribution of individual immune response to Staphylococcus aureus bacteremia on outcome has not been well studied. The objective was to relate the host cytokine response to outcome of Staphylococcus aureus bacteremia.

Design: Prospective observational study.

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Objective: Persons experiencing homelessness are a vulnerable population and are at increased risk for morbidity and all-cause mortality compared to the general population. This study sought to evaluate medication use, regular physician visits, and identify health conditions among the homeless population of Long Beach, California.

Methods: Two "brown bag" medication review events were held at homeless shelters in the Long Beach area.

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Antibiotic-resistant bacterial pathogens threaten public health. Because many antibiotics target specific bacterial enzymes or reactions, corresponding genes may mutate under selection and lead to antibiotic resistance. Accordingly, antimicrobials that selectively target overall microbial cell integrity may offer alternative approaches to therapeutic design.

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Background: A subset of vancomycin-treated patients with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) developed persistent positive blood cultures. Treatment eventually failed.

Methods: A retrospective study was conducted to determine whether early response on day 3 after initiation of vancomycin therapy for MRSA BSI was associated with reduced rates of persistent bacteremia, end-of-treatment failure, and infection-related mortality.

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We examined the effects of tigecycline on three types of exoproteins, α-type phenol-soluble modulins (PSMα1 to PSMα4), α-hemolysin, and protein A, in 13 methicillin-resistant Staphylococcus aureus isolates compared to those of clindamycin and linezolid. Paradoxical increases in PSMαs occurred in 77% of the isolates with tigecycline at 1/4 and 1/8 MICs and clindamycin at 1/8 MIC compared to only 23% of the isolates with linezolid at 1/8 MIC. Induction was specific to PSMα1 to PSMα4, as protein A and α-hemolysin production was decreased under the same conditions by all of the antibiotics used.

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Staphylococcus aureus strains (n = 50) causing complicated skin and skin structure infections produced various levels of phenol-soluble modulin alpha-type (PSMα) peptides; some produced more than twice that produced by the control strain (LAC USA300). TR-700 (oxazolidinone) and clindamycin strongly inhibited PSM production at one-half the MIC but exhibited weak to modest induction at one-fourth and one-eighth the MICs, primarily in low producers. Adequate dosing of these agents is emphasized to minimize the potential for paradoxical induction of virulence.

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Reports of vancomycin treatment failure for infections caused by susceptible methicillin-resistant Staphylococcus aureus (MRSA) strains with elevated minimum inhibitory concentration (MIC) has prompted use of high-dose therapy, but nephrotoxicity is a concern. We determined whether clinical and molecular epidemiologic parameters can be used to guide empiric vancomycin therapy and strain susceptibility to alternative agents. Medical charts of 180 hospitalized adults with MRSA infections were reviewed.

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