Point of Care Molecular Testing: Current State and Opportunities for Diagnostic Stewardship.

Inappropriate ordering practices, either under or over ordering of diagnostic tests, are recognized problems with possible negative downstream consequences. As the menu of clinical tests, especially molecular tests grows, it is becoming increasingly important to provide guidance to providers on the appropriate utilization. Diagnostic stewardship programs have been established at many institutions to help direct the appropriate utilization of laboratory testing to ultimately guide patient management and treatment decisions. Many molecular tests have now received Clinical Laboratory Improvement Amendments (CLIA)-waived status for use in a point-of-care (POC) setting; however, parallel diagnostic stewardship programs have not been established to help guide providers on how best to use these tests. In this article, we will discuss the available molecular POC tests and opportunities and challenges for establishing diagnostic stewardship programs for molecular testing performed in the POC setting.

Epidemiology and Outcomes of Non-albicans Candida Bloodstream Infections in Transplant Recipients and Cancer Patients.

We performed a retrospective survey of non-Candida albicans candidemia in patients with cancer, including those with solid tumors and those with hematological malignancies as well as transplants patients both, solid-organ transplant recipients and hematopoietic stem cell transplant recipients. The study was performed at two healthcare centers in New York City and covered the years 2018-2022. A total of 292 patients (318 isolates) were included in the study. In order of frequency, C. glabrata (38%) was the most common species recovered, followed by C. parapsilosis (19.2%), C. tropicalis (12.6%), C. krusei (10.7%), C. lusitaniae (5.7%), and C. guilliermondii (4.4%). Micafungin was the most common antifungal treatment and 18.5% of patients were on antifungal prophylaxis. The 30-day crude mortality was 40%. 4.5% of patients had more than one non-albicans species detected. In conclusion, this study represents one of the largest surveys of non-albicans species in cancer and transplant patients and provides data on the current epidemiology of these Candida species in this patient population.

Longitudinal Viral Load Monitoring Using Home-Collected Dried Blood Spot Specimens of MSM Living with HIV: Results from a Feasibility Pilot Study.

Novel viral load monitoring strategies are needed to help individuals maintain an undetectable viral load (UVL). In 2018, U.S. MSM living with HIV with a past detectable VL received a dried blood spot (DBS) kit at baseline and 3-month follow-up and returned specimens to a research laboratory. Of 56 consenting participants, 91% returned specimens at baseline and 77% at 3-month follow-up; 74% who returned two specimens had UVL at both time points. At-home DBS collection and longitudinal VL monitoring is feasible among U.S. MSM with fluctuating viral load. This complementary approach to clinical care could improve viral suppression maintenance.

RESUMEN: Se necesitan nuevas estrategias para evaluar los niveles de la carga viral para ayudar a las personas viviendo con VIH a mantener una carga viral indetectable (CVI). En 2018, hombres viviendo con VIH, que reportaron sexo con hombres y una carga viral detectable, recibieron dos paquetes de materiales para colectar muestras de sangre seca después de completar una evaluación basal y después de tres meses de seguimiento. Participantes devolvieron las muestras de sangre seca a un laboratorio. De 56 participantes que dieron su consentimiento a participar en el estudio, el 91% devolvió una muestra de sangre seca al inicio del estudio y el 77% a los 3 meses de seguimiento. Además, el 74% que devolvió dos muestras de sangre seca tenían CVI en ambos puntos de tiempo. La colección de sangre seca en el hogar y el monitoreo longitudinal de la carga viral de VIH es factible entre los hombres viviendo con el VIH y que tienen sexo con hombres. Los resultados de este estudio pueden proporcionar un enfoque complementario a la atención clínica para mejorar la supresión viral del VIH.

Head and neck infections in children due to Eikenella corrodens: Report of three cases and review of literature.

INTRODUCTION: Eikenella corrodens is a small, nonmotile Gram-negative rod that is part of the normal flora in the mouth, upper respiratory, gastrointestinal, and genitourinary tracts. It is classically found in human bite (fist to mouth) infections but is also seen in respiratory tract and head and neck infections. METHODS: We describe three cases of E. corrodens causing head and neck infections in children seen in our institution between 2013 and 2019. We also reviewed the available literature on pediatric head and neck infections caused by E. corrodens. RESULTS: All 3 children recovered and fit the trends identified in the 58 patients published in the literature from 1976 to 2019. CONCLUSIONS: E. corrodens is responsible for a range of head and neck infections in pediatric patients. It is a not infrequent cause of head and neck infections in children and should be considered when selecting presumptive antibiotic therapy.

Architect i2000 SR has improved turnaround time for infectious disease serology testing over Vitros ECiQ.

BACKGROUND: Vitros ECiQ and Architect i2000 SR are two automated instruments used to detect serology biomarkers of hepatitis A, B and C viruses, and HIV infections. We compared performance of the Architect to the Vitro EciQ after implementation at our institution. METHODS: A retrospective review was performed to compare patient samples tested on the Vitros ECiQ or Architect for hepatitis and HIV serological assays. The positivity rate, frequency of equivocal results, turnaround times (TAT), and hands-on time (HOT) were analyzed. RESULTS: There was no statistical difference in the positivity rate between the two instruments, with the exception of two assays. An increase in equivocal results was observed for the Architect (0.2% vs 0.5%). Notably, the TAT for the Architect i2000 was shorter for all except one assay (31.6 vs 33.7 hours) and demonstrated improved workflow. CONCLUSIONS: Overall, both instruments performed comparably. Architect had shorter TAT over Vitros.

Outsourcing Microbiology Services in Medical Centers: Is It Worth It?

BACKGROUND: Outsourcing of microbiology laboratory services is a growing trend in US medical centers. Data on the actual impact of outsourcing on patient care, safety, and medical education, including costs, are limited. The objective of this study was to examine the published literature on the potential benefits and harms when medical centers outsource common microbiology services. METHODS: We conducted a 16-step literature search of PubMed and Embase. Articles were selected for full-text review if their content matched our key questions: (1) What are the potential benefits of outsourcing core microbiology laboratory testing? (2) What are the potential harms to patient care and medical education when medical centers outsource essential microbiology services? RESULTS: The initial search yielded 6111 unique published articles; 36 were selected for full-text review, which resulted in the identification of 8 articles that addressed our key questions (2 editorials, 3 editorials with observational data, 1 survey, 1 case series, and 1 study of blood culture transport). These articles described a variety of issues, including longer turnaround times for blood cultures that resulted in delays in diagnosis and treatment, errors that resulted in patient morbidity, limited cost savings, and communication barriers. CONCLUSIONS: In this study, with the exception of the blood culture transport study, we found no published prospective studies that quantified the effects of outsourcing microbiology services on patient care, patient safety, or medical education. However, these largely anecdotal reports suggest that outsourcing microbiology services may have a detrimental impact on medical education, especially infectious disease training programs.

Rapid Molecular Detection and Differentiation of Influenza Viruses A and B.

Influenza is a contagious respiratory illness caused by influenza viruses A and B in humans and causes a significant amount of morbidity and mortality every year. The Influenza A and B assay was the first CLIA-waived molecular rapid flu test available. The Influenza A and B test works by employing isothermal amplification with influenza-specific primers followed by target detection with molecular beacon probes. Here, the performance of the Influenza A and B assay on frozen, archived nasopharyngeal swab (NPS) specimens stored in viral transport medium (VTM) were compared to a respiratory panel assay. The performance of the Influenza A and B assay was evaluated by comparing the results to the respiratory panel reference method. The sensitivity for total influenza virus A was 67.5% (95% CI (CI), 56.6-78.5) and the specificity was 86.9% (CI, 71.0-100). For influenza virus B testing, the sensitivity and specificity were 90.2% (CI, 68.5-100) and 98.8% (CI, 68.5-100), respectively. This system has the advantage of a significantly shorter test time than any other currently available molecular assay and the simple, pipette-free procedure runs on a fully integrated, closed, small-footprint system. Overall, the Influenza A and B assay evaluated in this study has the potential to serve as a point-of-care rapid influenza diagnostic test.

Natural and ion-exchanged illite clays reduce bacterial burden and inflammation in cutaneous meticillin-resistant Staphylococcus aureus infections in mice.

Discoveries associated with antibacterial activity of hydrated clays necessitate assessments of in vivo efficacy, practical use and safety. Surface properties of clays can lead to variations in the composition and abundance of bound compounds or ions, thus affecting antibacterial activity. Since exchangeable metal ions released from the clay surface are responsible for in vitro antibacterial activity, we evaluated the in vivo antibacterial efficacy of four natural clays (one illite clay, two montmorillonite clays and one kaolinite clay) and three ion-exchanged, antibacterial clays against superficial, cutaneous meticillin-resistant Staphylococcus aureus (MRSA) infections in mice. Superficial, cutaneous wounds on the back of SKH1-Elite mice were generated and subsequently infected with MRSA. Following twice daily applications of a hydrated clay poultice to infected wounds for 7  days, we observed significant differences in the in vivo antibacterial efficacy between different types of clays. The natural and ion-exchanged illite clays performed best, as measured by bacterial load, inflammatory response and gross wound morphology with significant decreases in bacterial viability and dermatitis. Topical application of kaolinite clay was the least effective, resulting in the lowest decrease in bacterial load and exhibiting severe dermatitis. These data suggest that specific types of clays may offer a complementary and integrative strategy for topically treating MRSA and other cutaneous infections. However, since natural clays exhibit in vitro antibacterial variability and vary vastly in surface chemistries, adsorptive/absorptive characteristics and structural composition, the properties and characteristics of illite clays could aid in the development of standardized and customized aluminosilicates for topical infections.

Ribosomal RNA gene sequencing for early diagnosis of Blastomyces dermatitidis infection.

Prompt detection and identification of fungal pathogens at the genus and species level is critical in order to provide timely antifungal therapy. Here, we highlight the vital role of molecular diagnostics in achieving a fast and definitive diagnosis of disseminated blastomycosis in a diabetic patient presenting as a brain mass initially thought to be tumoral in nature. A broad-range PCR amplification and sequencing of the fungal ribosomal RNA genes on brain biopsy tissue obtained during elective craniotomy revealed a final microbial identification of Ajellomyces dermatitidis (telemorph of Blastomyces dermatitidis).

Reducing Unnecessary and Duplicate Ordering for Ovum and Parasite Examinations and Clostridium difficile PCR in Immunocompromised Patients by Using an Alert at the Time of Request in the Order Management System.

We implemented hospital information system (HIS) alerts to deter unnecessary test orders for ovum and parasite (O&P) exams and Clostridium difficile PCR. The HIS alerts decreased noncompliant O&P orders (orders after >72 h of hospitalization) from 49.8% to 30.9%, an overall decrease of 19%, and reduced noncompliant C. difficile PCR orders (orders <7 days after a previous positive result) from 30.6% to 19.2%, an overall decrease of 31.9%.

Bacteremia caused by Arcobacter butzleri in an immunocompromised host.

Arcobacter butzleri is an emerging pathogen that has been implicated as the causative agent of persistent watery diarrhea. We describe a case involving a patient with chronic lymphocytic leukemia who developed invasive A. butzleri bacteremia. This case illustrates the unique challenges involved in diagnosing infections caused by emerging gastrointestinal pathogens.

Metal ions, not metal-catalyzed oxidative stress, cause clay leachate antibacterial activity.

Aqueous leachates prepared from natural antibacterial clays, arbitrarily designated CB-L, release metal ions into suspension, have a low pH (3.4-5), generate reactive oxygen species (ROS) and H2O2, and have a high oxidation-reduction potential. To isolate the role of pH in the antibacterial activity of CB clay mixtures, we exposed three different strains of Escherichia coli O157:H7 to 10% clay suspensions. The clay suspension completely killed acid-sensitive and acid-tolerant E. coli O157:H7 strains, whereas incubation in a low-pH buffer resulted in a minimal decrease in viability, demonstrating that low pH alone does not mediate antibacterial activity. The prevailing hypothesis is that metal ions participate in redox cycling and produce ROS, leading to oxidative damage to macromolecules and resulting in cellular death. However, E. coli cells showed no increase in DNA or protein oxidative lesions and a slight increase in lipid peroxidation following exposure to the antibacterial leachate. Further, supplementation with numerous ROS scavengers eliminated lipid peroxidation, but did not rescue the cells from CB-L-mediated killing. In contrast, supplementing CB-L with EDTA, a broad-spectrum metal chelator, reduced killing. Finally, CB-L was equally lethal to cells in an anoxic environment as compared to the aerobic environment. Thus, ROS were not required for lethal activity and did not contribute to toxicity of CB-L. We conclude that clay-mediated killing was not due to oxidative damage, but rather, was due to toxicity associated directly with released metal ions.

Exchangeable ions are responsible for the in vitro antibacterial properties of natural clay mixtures.

We have identified a natural clay mixture that exhibits in vitro antibacterial activity against a broad spectrum of bacterial pathogens. We collected four samples from the same source and demonstrated through antibacterial susceptibility testing that these clay mixtures have markedly different antibacterial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). Here, we used X-ray diffraction (XRD) and inductively coupled plasma--optical emission spectroscopy (ICP-OES) and--mass spectrometry (ICP-MS) to characterize the mineralogical and chemical features of the four clay mixture samples. XRD analyses of the clay mixtures revealed minor mineralogical differences between the four samples. However, ICP analyses demonstrated that the concentrations of many elements, Fe, Co, Cu, Ni, and Zn, in particular, vary greatly across the four clay mixture leachates. Supplementation of a non-antibacterial leachate containing lower concentrations of Fe, Co, Ni, Cu, and Zn to final ion concentrations and a pH equivalent to that of the antibacterial leachate generated antibacterial activity against E. coli and MRSA, confirming the role of these ions in the antibacterial clay mixture leachates. Speciation modeling revealed increased concentrations of soluble Cu(2+) and Fe(2+) in the antibacterial leachates, compared to the non-antibacterial leachates, suggesting these ionic species specifically are modulating the antibacterial activity of the leachates. Finally, linear regression analyses comparing the log10 reduction in bacterial viability to the concentration of individual ion species revealed positive correlations with Zn(2+) and Cu(2+) and antibacterial activity, a negative correlation with Fe(3+), and no correlation with pH. Together, these analyses further indicate that the ion concentration of specific species (Fe(2+), Cu(2+), and Zn(2+)) are responsible for antibacterial activity and that killing activity is not solely attributed to pH.

Effects of antibacterial mineral leachates on the cellular ultrastructure, morphology, and membrane integrity of Escherichia coli and methicillin-resistant Staphylococcus aureus.

BACKGROUND: We have previously identified two mineral mixtures, CB07 and BY07, and their respective aqueous leachates that exhibit in vitro antibacterial activity against a broad spectrum of pathogens. The present study assesses cellular ultrastructure and membrane integrity of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli after exposure to CB07 and BY07 aqueous leachates. METHODS: We used scanning and transmission electron microscopy to evaluate E. coli and MRSA ultrastructure and morphology following exposure to antibacterial leachates. Additionally, we employed Baclight LIVE/DEAD staining and flow cytometry to investigate the cellular membrane as a possible target for antibacterial activity. RESULTS: Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging of E. coli and MRSA revealed intact cells following exposure to antibacterial mineral leachates. TEM images of MRSA showed disruption of the cytoplasmic contents, distorted cell shape, irregular membranes, and distorted septa of dividing cells. TEM images of E. coli exposed to leachates exhibited different patterns of cytoplasmic condensation with respect to the controls and no apparent change in cell envelope structure. Although bactericidal activity of the leachates occurs more rapidly in E. coli than in MRSA, LIVE/DEAD staining demonstrated that the membrane of E. coli remains intact, while the MRSA membrane is permeabilized following exposure to the leachates. CONCLUSIONS: These data suggest that the leachate antibacterial mechanism of action differs for Gram-positive and Gram-negative organisms. Upon antibacterial mineral leachate exposure, structural integrity is retained, however, compromised membrane integrity accounts for bactericidal activity in Gram-positive, but not in Gram-negative cells.

Electrostatic interactions affect nanoparticle-mediated toxicity to gram-negative bacterium Pseudomonas aeruginosa PAO1.

Nanoscale materials can have cytotoxic effects. Here we present the first combined empirical and theoretical investigation of the influence of electrostatic attraction on nanoparticle cytotoxicity. Modeling electrostatic interactions between cells and 13 nm spheres of zinc oxide nanoparticles provided insight into empirically determined variations of the minimum inhibitory concentrations between four differently charged isogenic strains of Pseudomonas aeruginosa PAO1. We conclude that controlling the electrostatic attraction between nanoparticles and their cellular targets may permit the modulation of nanoparticle cytotoxicity.

Telemedicine facilitates CHF home health care for those with systolic dysfunction.

An estimated 5 million Americans have congestive heart failure (CHF) and one in five over the age of 40 will develop CHF. There are numerous examples of CHF patients living beyond the years normally expected for people with the disease, usually attributed to taking an active role in disease management. A relatively new alternative for CHF outpatient care is telemedicine and e-health. We investigated the effects of a 6-week in-home telemedicine education and monitoring program for those with systolic dysfunction on the utilization of health care resources. We also measured the effects of the unit 4.5 months after its removal (a total of 6 months post introduction of the unit into the home). Concurrently, we assessed participants' perceptions of the value of having a telemedicine unit. Participants in the telemedicine group reported weighing more times a week with less variability than did the control group. Telemedicine led to a reduction in physician and emergency department visits and those in the experimental group reported the unit facilitating self-care, though this was not significantly different from the control group (possibly due to small sample size). These findings suggest a possibility for improvement in control of CHF when telemedicine is implemented. Our review of the literature also supports the role of telemedicine in facilitating home health care and self-management for CHF patients. There are many challenges still to be addressed before this potential can be reached and further research is needed to identify opportunities in telemedicine.