The Effect of Povidone-Iodine Irrigation on the Efficacy of Antibiotic Cement In Vitro.

Povidone-iodine is a common antiseptic demonstrating success in reducing infection rates in primary arthroplasty; however, recent data suggest that its use in revision arthroplasty may increase infection rates. This study evaluated the effect of povidone-iodine solution on antibiotic cement and investigated the connection between povidone-iodine and increased infection rates in revision arthroplasty. Sixty antibiotic cement samples (ACSs) were formed using gentamicin-impregnated cement. The ACSs were divided into three groups: group A (n=20) was subject to a 3-minute povidone-iodine soak followed by a saline rinse; group B (n=20) underwent a 3-minute saline soak; and group C (n=20) underwent only a saline rinse. The antimicrobial activity of the samples was tested using a Kirby-Bauer-like assay using Staphylococcus epidermidis. The zone of inhibition (ZOI) was measured every 24 hours for 7 days. All groups possessed the greatest antimicrobial activity at 24 hours. Group C displayed a mass-corrected ZOI of 395.2 mm/g, which was statistically greater than the group B ZOI (313.2 mm/g, P<.05) but not the group A ZOI (346.5 mm/g, P>.05). All groups demonstrated a decrease in antimicrobial activity at 48 through 96 hours, with no significant difference at any time point. Prolonged soaking of antibiotic cement in a povidone-iodine or saline solution results in elution of the antibiotic into the irrigation solution, blunting initial antibiotic concentration. When using antibiotic cement, antiseptic soaks or irrigation should be focused prior to cementation. [Orthopedics. 2024;47(1):10-14.].

Vacuoles in the Breast: A Histologic Clue for an Unusual Presentation of an Atypical Organism.

Infections with nontuberculous mycobacteria (NTM) are increasing in prevalence worldwide, and this group of organisms is emerging as significant clinical pathogens. We present a case of a 58-year-old female with persistent furuncles of the breast who was found to have an NTM infection. This case is unique for the lack of risk factors for NTM in the patient's history, the location of the infection in the breast, and the close cooperation needed across disciplines to arrive at the diagnosis. This multi-disciplinary discussion considers the classic clinical presentation of NTM, it is a characteristic morphological appearance on histopathology, the differential diagnosis, treatment, and the ultimate outcome of the case. This case report and discussion will assist both clinicians and pathologists in the diagnosis of this important infectious disease.

Implementation of an HIV RNA Qualitative PCR Assay in an HIV Diagnostic Algorithm: A Single-Institution Experience.

OBJECTIVES: Boston Medical Center (BMC) is a private, not-for-profit 514-bed academic medical center and legacy safety net hospital serving a diverse global patient population. BMC recently implemented a new HIV-1/HIV-2 Qualitative RNA PCR (HIV RNA QUAL) cleared by the US Food and Drug Administration to (1) replace antibody discrimination follow-up testing after a reactive fourth-generation (4G) serology screen and (2) use as a stand-alone diagnostic for suspected seronegative acute HIV infection. METHODS: This report summarizes the results of a production monitor for the first 3 months postimplementation. RESULTS: The monitor characterized test utilization, diagnostic turnaround time, impact on send-out testing, results reflexed to HIV RNA discrimination follow-up, and discrepancies between screening and HIV RNA results that necessitated additional investigation. Another element was the novelty of using HIV RNA QUAL while awaiting the existing Centers for Disease Control and Prevention HIV testing algorithm update. The 4G screening components and the HIV RNA QUAL were also used to create an algorithm specific to and compliant with current guidelines for screening patients on HIV preexposure prophylaxis. CONCLUSIONS: Based on our findings, this new test algorithm may be reproducible and instructive at other institutions.

Comparison of Analytical Sensitivity (Limit of Detection) of Xpert MTB/RIF and Xpert MTB/RIF Ultra for Non-Sputum Specimens.

Tuberculosis (TB) is a significant public health threat and has remained a leading cause of death in many parts of the world. Rapid and accurate testing and timely diagnosis can improve treatment efficacy and reduce new exposures. The Cepheid Xpert® MTB/RIF tests have two marketed products (US-IVD and Ultra) that are widely accepted for diagnosis of TB but have not yet been approved for non-sputum specimens. Despite numerous studies in the literature, no data for the analytical sensitivity of these two products on the non-sputum samples are available to date. This is the first study that systematically determined the analytical sensitivities of both US-IVD and Ultra tests on cerebrospinal fluid (CSF), tissue, and bronchoalveolar lavage (BAL). The limits of detection (LoDs) on the US-IVD test for both Mycobacterium tuberculosis and rifampin resistance in CFU/mL, respectively, were as follows: CSF (3.3 and 4.6), tissue (15 and 23), and bronchoalveolar lavage (BAL) (45 and 60), and on the Ultra test: CSF (0.16 and 2.7), tissue (0.11 and 12), and BAL (0.65, and 7.5). Overall, the analytical sensitivities of the Ultra test were substantially better than US-IVD for all sample types tested. This study provided a foundation for using either the US-IVD or Ultra test for the early detection of both pulmonary and extrapulmonary (EP) TB. Furthermore, using Ultra could result in higher TB case detection rates in subjects with paucibacillary TB and EP TB, positively impacting WHO goals to eradicate TB.

Single-center investigation on central-line-associated bloodstream infections and blood-culture contamination during the early months of the coronavirus disease 2019 (COVID-19) pandemic.

In this retrospective cohort study, we assessed central-line-associated bloodstream infections (CLABSIs) and blood-culture contamination frequency during the first pandemic wave. Coronavirus disease 2019 (COVID-19) was significantly associated with CLABSI and blood-culture contamination. In the COVID-19 cohort, malignancy was associated with CLABSI. Black race, end-stage renal disease, and obesity were associated with blood-culture contamination.

Multisite biologic tissue SARS-CoV-2 PCR testing in kidney transplantation from a COVID-positive donor.

With a high community transmission rate, SARS-CoV-2 has profoundly exacerbated the shortage of organs. Although the risk of donor-recipient transmission of SARS-CoV-2 is anecdotally low, an organ-specific infection analysis of procured organs from SARS-CoV-2 positive donors has yet to be established. Using a combination of clinically available and research-only polymerase chain reaction methods, organ preservation fluid and renal parenchymal tissues were tested for SARS-CoV-2 from the kidney of a SARS-CoV-2-positive donor prior to transplantation. The recipient has remained SARS-CoV-2 negative and clinically well, with excellent graft function 120 days post-transplantation.

A Fatal Fungal Infection: Cryptococcus gattii (VGI) Meningitis in Texas.

Cryptococcus gattii is an underrecognized cause of meningitis, especially in nonendemic regions. This report details C gattii disease progression from admission to autopsy in an otherwise healthy 40-year-old male in Texas. It brings awareness to an often unsuspected organism that can cause severe infection requiring early recognition and treatment in immunocompetent individuals.

A Comparison of Seegene Technologies Novaplex SARS-CoV-2 Variants I, II, and IV Assays with Spike Gene Sequencing for Detection of Known Severe Acute Respiratory Syndrome Coronavirus 2 Variants.

Tracking new and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has become increasingly important for public health responses, primarily because of variant-dependent transmission, disease severity, and treatment decisions. This evaluation compared Seegene Technologies Novaplex SARS-CoV-2 Variants I, II, and IV (I,II&IV) assays to detect known SARS-CoV-2 variants using traditional spike gene Sanger sequencing results as the gold standard reference. Both RNA extraction and extraction-free protocols were assessed. A total of 156 samples were included in this study. There was 100% (109/109) overall agreement (95% CI, 96.7%-100%) between the spike gene sequencing and the I,II&IV results using extracted RNA for the variants included in the Novaplex assay menus. The RNA extraction-free method was 91.7% (143/156) as sensitive (95% CI, 86.2%-95.5%) as the traditional RNA extraction method. Using the extraction-free method on samples with higher cycle threshold values (>30) resulted in some mutations not being detected, presumably due to lower nucleic acid concentrations in the original samples. In conclusion, the I,II&IV assays provide an accurate, rapid, and less labor-intensive method for detecting SARS-CoV-2 and identifying known variants of interest and concern. The RNA extraction-free method for samples with cycle threshold of <30 could be cost-effective for surveillance purposes. However, spike gene sequencing retains the advantage of detecting more and new variants.

16S rRNA gene sequencing data of the human skin microbiome before and after swimming in the ocean.

These data represent the abundance, diversity and predicted function gene profiles of the microbial communities present on human skin before and after swimming in the ocean. The skin microbiome has been shown to provide protection against infection from pathogenic bacteria. It is well-known that exposure to ocean water can cause skin infection, but little is known about how exposure can alter the bacterial communities on the skin. Skin microbiome samples were collected from human participants before and after swimming in the ocean. These data were used to analyze the changes in abundance and diversity of microbial communities on the skin and the changes in the functional profiles of the bacteria, specifically focusing on genes involved in antibiotic resistance and bacterial virulence.

Acquisition of antibiotic resistance genes on human skin after swimming in the ocean.

The skin is a complex organ responsible for protecting the body from physical, chemical and biological insults. The skin microbiome is known to play an important role in protecting the host from skin infections. This study examined the skin microbiome and the changes in antibiotic resistance genes (ARGs), antibiotic biosynthesis genes (ABSGs) and virulence factor genes (VFGs) on human skin before and after swimming in the ocean. Skin microbiome samples were collected from human participants before and after they swam in the ocean, and at 6 h and 24 h post-swim. The samples were analyzed using 16S rRNA gene and shotgun metagenomic sequencing. The results showed that not only is the skin microbiome composition altered after swimming, but the abundance and diversity of ARGs, ABSGs and VFGs on the skin increased post-swim. Overall, there was an increase in total ARGs by 70.6% from before to after swimming. The elevated number of ARGs persisted and continued to increase for at least 6 h post-swim with greater than a 300% increase in comparison with samples collected before ocean swimming. The outcomes of the study support the epidemiological observations of increased risk of skin infections after swimming in the ocean. Cleaning the skin immediately after recreational ocean activities is recommended to reduce the opportunity for infection.

Evaluation of a SARS-CoV-2 lateral flow assay using the plaque reduction neutralization test.

As new tests and technologies advance our understanding and diagnostic capabilities of the severe acute respiratory syndrome coronavirus 2 and the coronavirus disease 2019, they must be appropriately validated to make sure test performance is following manufacturer claims. In this study, we evaluated the Vazyme 2019-nCoV IgG/IgM Detection Kit, which is a lateral flow assay (LFA), by the plaque reduction neutralization test (PRNT) using 100 patient plasma/serum samples. As compared to the PRNT results, the Vazyme LFA had 95.9% sensitivity and 96.1% specificity. Along with the increased need for rapid, effective, and affordable point of care tests to help provide meaningful epidemiological data, we demonstrated that the Vazyme LFA performed well on IgG detection but cannot be judged on the performance of IgM detection using PRNT alone. However, our observation of the low IgM-positive rate supported the poor performance of IgM detection of this LFA which led to the disapproval of its Emergency Use Authorization recently.