Low infectivity among asymptomatic patients with a positive severe acute respiratory coronavirus virus 2 (SARS-CoV-2) admission test at a tertiary care center, 2020-2022.

We used a strand-specific RT-qPCR to evaluate viral replication as a surrogate for infectiousness among 242 asymptomatic inpatients with a positive severe acute respiratory coronavirus virus 2 (SARS-CoV-2) admission test. Only 21 patients (9%) had detectable SARS-CoV-2 minus-strand RNA. Because most patients were found to be noninfectious, our findings support the suspension of asymptomatic admission testing.

Use of a severe acute respiratory coronavirus virus 2 (SARS-CoV-2) strand-specific assay to evaluate for prolonged viral replication >20 days from illness onset.

Severe acute respiratory coronavirus virus 2 (SARS-CoV-2) real-time reverse-transcription polymerase chain reaction (rRT-PCR) strand-specific assay can be used to identify active SARS-CoV-2 viral replication. We describe the characteristics of 337 hospitalized patients with at least 1 minus-strand SARS-CoV-2 assay performed >20 days after illness onset. This test is a novel tool to identify high-risk hospitalized patients with prolonged SARS-CoV-2 replication.

Butyrate Differentiates Permissiveness to Clostridioides difficile Infection and Influences Growth of Diverse C. difficile Isolates.

A disrupted "dysbiotic" gut microbiome engenders susceptibility to the diarrheal pathogen Clostridioides difficile by impacting the metabolic milieu of the gut. Diet, in particular the microbiota-accessible carbohydrates (MACs) found in dietary fiber, is one of the most powerful ways to affect the composition and metabolic output of the gut microbiome. As such, diet is a powerful tool for understanding the biology of C.

Getting to zero: Impact of a device to reduce blood culture contamination and false-positive central-line-associated bloodstream infections.

Objective: To assess the impact of initial specimen diversion device (ISDD) on inpatient and emergency department blood culture contamination (BCC), central-line-associated bloodstream infection (CLABSI) standardized infection ratios (SIRs), and antibiotic administration.

Design: Single-center quasi-experimental prospective cohort study wherein phlebotomists used traditional venipuncture with or without the ISDD while registered nurses (RNs) used traditional venipuncture.

Method: BCC events among phlebotomists and RNs were observed and compared from March 17, 2019, through January 21, 2020, defined by contaminant detection in 1 of 4 bottles for matched sets or 1 of 2 bottles in both subsets for coagulase negative staphylococci.

Clinical Outcomes of Treated and Untreated C. difficile PCR-Positive/Toxin-Negative Adult Hospitalized Patients: a Quasi-Experimental Noninferiority Study.

Clostridioides difficile infection (CDI) is routinely diagnosed by PCR, with or without toxin enzyme immunoassay testing. The role of therapy for positive PCR and negative toxin remains unclear. The objective of this study was to determine whether clinical outcomes of PCR/cycle threshold-based toxin (CT-toxin) individuals vary by result reporting and treatment strategy.

Case-control study evaluating risk factors for SARS-CoV-2 outbreak amongst healthcare personnel at a tertiary care center.

Background: Despite several outbreaks of SARS-CoV-2 amongst healthcare personnel (HCP) exposed to COVID-19 patients globally, risk factors for transmission remain poorly understood.

Methods: We conducted an outbreak investigation and case-control study to evaluate SARS-CoV-2 transmission risk in an outbreak among HCP at an academic medical center in California that was confirmed by whole genome sequencing.

Results: A total of 7/9 cases and 93/182 controls completed a voluntary survey about risk factors.

The Role of Vision in the Emergence of Mate Preferences.

Cross-cultural research has repeatedly demonstrated sex differences in the importance of partner characteristics when choosing a mate. Men typically report higher preferences for younger, more physically attractive women, while women typically place more importance on a partner's status and wealth. As the assessment of such partner characteristics often relies on visual cues, this raises the question whether visual experience is necessary for sex-specific mate preferences to develop.

Could the prevention of health care-associated infections increase hospital cost? The financial impact of health care-associated infections from a hospital management perspective.

Background: The financial burden health care-associated infections (HAIs) have on patients, payers, and hospitals is not clear. Although patient safety is the highest priority, administrators require data to justify the expense of HAI reduction programs.

Methods: Chart review was performed to identify HAIs for patients discharged from Stanford Hospital.

Dual Reporting of Clostridioides difficile PCR and Predicted Toxin Result Based on PCR Cycle Threshold Reduces Treatment of Toxin-Negative Patients without Increases in Adverse Outcomes.

Nucleic acid amplification tests are commonly used to diagnose infection (CDI). Two-step testing with a toxin enzyme immunoassay is recommended to discriminate between infection and colonization but requires additional resources. Prior studies showed that PCR cycle threshold ( ) can predict toxin positivity with high negative predictive value.

Real-Time Electronic Tracking of Diarrheal Episodes and Laxative Therapy Enables Verification of Clostridium difficile Clinical Testing Criteria and Reduction of Clostridium difficile Infection Rates.

Health care-onset health care facility-associated infection (HO-CDI) is overdiagnosed for several reasons, including the high prevalence of colonization and the inability of hospitals to limit testing to patients with clinically significant diarrhea. We conducted a quasiexperimental study from 22 June 2015 to 30 June 2016 on consecutive inpatients with test orders at an academic hospital. Real-time electronic patient data tracking was used by the laboratory to enforce testing criteria (defined as the presence of diarrhea [≥3 unformed stools in 24 h] and absence of laxative intake in the prior 48 h).

Helicobacter pylori usurps cell polarity to turn the cell surface into a replicative niche.

Helicobacter pylori (Hp) intimately interacts with the gastric epithelial surface and translocates the virulence factor CagA into host cells in a contact-dependent manner. To study how Hp benefits from interacting with the cell surface, we developed live-cell microscopy methods to follow the fate of individual bacteria on the cell surface and find that Hp is able to replicate and form microcolonies directly over the intercellular junctions. On polarized epithelia, Hp is able to grow directly on the apical cell surface in conditions that do not support the growth of free-swimming bacteria.

Microarray detection of human parainfluenzavirus 4 infection associated with respiratory failure in an immunocompetent adult.

A pan-viral DNA microarray, the Virochip (University of California, San Francisco), was used to detect human parainfluenzavirus 4 (HPIV-4) infection in an immunocompetent adult presenting with a life-threatening acute respiratory illness. The virus was identified in an endotracheal aspirate specimen, and the microarray results were confirmed by specific polymerase chain reaction and serological analysis for HPIV-4. Conventional clinical laboratory testing using an extensive panel of microbiological tests failed to yield a diagnosis.

Investigation of mediastinitis due to coagulase-negative staphylococci after cardiothoracic surgery.

Six cases of coagulase-negative staphylococcal mediastinitis were identified in the latter half of 1999. A new preoperative cleansing solution was suspected by hospital staff to be a factor in the outbreak. We evaluated this possible risk factor along with other known and suspected surgical site infection risk factors in this case-control study.

Prolonged incubation and extensive subculturing do not increase recovery of clinically significant microorganisms from standard automated blood cultures.

An extensive blood culture protocol, including prolonged incubation of cultures, for 215 patients believed to have had endocarditis yielded only 3 clinically relevant results. Twenty-four Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella (i.e.

Helicobacter pylori CagA induces a transition from polarized to invasive phenotypes in MDCK cells.

CagA is a bacterial effector protein of Helicobacter pylori that is translocated via a type IV secretion system into gastric epithelial cells. We previously described that H. pylori require CagA to disrupt the organization and assembly of apical junctions in polarized epithelial cells.

Phosphorylation-independent effects of CagA during interaction between Helicobacter pylori and T84 polarized monolayers.

To extend our knowledge of host-cell targets of Helicobacter pylori, we characterized the interaction between H. pylori and human T84 epithelial cell polarized monolayers. Transcriptional analysis by use of human microarrays and a panel of isogenic H.

Reemerging leptospirosis, California.

Leptospirosis is a reemerging infectious disease in California. Leptospirosis is the most widespread zoonosis throughout the world, though it is infrequently diagnosed in the continental United States. From 1982 to 2001, most reported California cases occurred in previously healthy young adult white men after recreational exposures to contaminated freshwater.

Comparison of Campylobacter jejuni isolates implicated in Guillain-Barré syndrome and strains that cause enteritis by a DNA microarray.

We asked whether Campylobacter jejuni isolated from patients with Guillain-Barré syndrome (GBS) differ from isolates isolated from patients with uncomplicated gastrointestinal infection using DNA microarray analysis. We found that specific GBS genes or regions were not identified, and microarray analysis confirmed significant genomic heterogeneity among the isolates.

Growth phase-dependent response of Helicobacter pylori to iron starvation.

Iron is an essential nutrient that is often found in extremely limited available quantities within eukaryotic hosts. Because of this, many pathogenic bacteria have developed regulated networks of genes important for iron uptake and storage. In addition, it has been shown that many bacteria use available iron concentrations as a signal to regulate virulence gene expression.

Disruption of the epithelial apical-junctional complex by Helicobacter pylori CagA.

Helicobacter pylori translocates the protein CagA into gastric epithelial cells and has been linked to peptic ulcer disease and gastric carcinoma. We show that injected CagA associates with the epithelial tight-junction scaffolding protein ZO-1 and the transmembrane protein junctional adhesion molecule, causing an ectopic assembly of tight-junction components at sites of bacterial attachment, and altering the composition and function of the apical-junctional complex. Long-term CagA delivery to polarized epithelia caused a disruption of the epithelial barrier function and dysplastic alterations in epithelial cell morphology.

pH-regulated gene expression of the gastric pathogen Helicobacter pylori.

Colonization by the gastric pathogen Helicobacter pylori has been shown to be intricately linked to the development of gastritis, ulcers, and gastric malignancy. Little is known about mechanisms employed by the bacterium that help it adapt to the hostile environment of the human stomach. In an effort to extend our knowledge of these mechanisms, we utilized spotted-DNA microarrays to characterize the response of H.