Lacticaseibacillus rhamnosus CRL 2244 secreted metabolites display killing and antibiotic synergistic activity against multi-drug resistant pathogens.

A growing increase in the number of serious infections caused by multidrug resistant bacteria (MDR) is challenging our society. Despite efforts to discover novel therapeutic options, few antibiotics targeting MDR have been approved by the Food and Drug Administration (FDA). Lactic acid bacteria have emerged as a promising therapeutic alternative due to their demonstrated ability to combat MDR pathogens in vitro. Our previous co-culture studies showed Lacticaseibacillus rhamnosus CRL 2244 as having a potent killing effect against carbapenem-resistant Acinetobacter baumannii (CRAB) strains. Here we report that cell-free conditioned media (CFCM) samples obtained from Lcb. rhamnosus CRL 2244 cultures incubated at different times display antimicrobial activity against 43 different pathogens, including CRAB, methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase Klebsiella pneumoniae (KPC)-positive strains. Furthermore, transwell and ultrafiltration analyses together with physical and chemical/biochemical tests showed that Lcb. rhamnosus CRL 2244 secretes a <3 kDa metabolite(s) whose antimicrobial activity is not significantly impaired by mild changes in pH, temperature and various enzymatic treatments. Furthermore, sensitivity and time-kill assays showed that the bactericidal activity of the Lcb. rhamnosus CRL 2244 metabolite(s) enhances the activity of some current FDA approved antibiotics. We hypothesize that this observation could be due to the effects of Lcb. rhamnosus CRL 2244 metabolite(s) on cell morphology and the enhanced transcriptional expression of genes coding for the phenylacetate (PAA) and histidine catabolic Hut pathways, metal acquisition and biofilm formation, all of which are associated with bacterial virulence. Interestingly, the extracellular presence of Lcb. rhamnosus CRL 2244 induced the transcription of the gene coding for the CidA/LgrA protein, which is involved in programmed cell death in some bacteria. Overall, the findings presented in this report underscore the promising potential of the compound(s) released by Lcb. rhamnosus CRL2244 as an alternative and/or complementary option to treat infections caused by A. baumannii as well as other MDR bacterial pathogens.

Comparison of available methods to evaluate cefiderocol susceptibility in Acinetobacter spp.

Recently, considerable uncertainty has arisen concerning the appropriate susceptibility testing for cefiderocol in gram-negative bacilli, particularly in the context of its application to Acinetobacter spp. The optimal method for assessing the susceptibility levels of Acinetobacter spp. to cefiderocol remains a subject of debate due to substantial disparities observed in the values obtained through various testing procedures. This study employed four minimum inhibitory concentration (MIC) methodologies and the disk diffusion to assess the susceptibility of twenty-seven carbapenem resistant (CR)-Acinetobacter strains to cefiderocol. The results from our study reveal significant variations in the minimum inhibitory concentration (MIC) values obtained with the different methods and in the level of agreement in interpretation categories between the different MIC methods and the disk diffusion test. Among the MIC methods, there was relatively more consistency in reporting the interpretation categories. For European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, the categorical agreement (CA) for MIC methods ranged between 66.7 and 81.5%. On the other hand, the essential agreement (EA) values were as low as 18.5-29.6%. The CA between MIC methods and disk diffusion was 81.5%. These results emphasize the need for a reliable, accurate, and clinically validated methodology to effectively assess the susceptibility of Acinetobacter spp. to cefiderocol. The wide variability observed in our study highlights the importance of standardizing the susceptibility testing process for cefiderocol to ensure consistent and reliable results for clinical decision-making.

Hetero-antagonism of avibactam and sulbactam with cefiderocol in carbapenem-resistant Acinetobacter spp.

The emergence of Gram-negative bacteria resistant to multiple antibiotics, particularly carbapenem-resistant (CR) Acinetobacter strains, poses a significant threat globally. Despite efforts to develop new antimicrobial therapies, limited progress has been made, with only two drugs-cefiderocol and sulbactam-durlobactam-showing promise for CR-Acinetobacter infections. Cefiderocol, a siderophore cephalosporin, demonstrates promising efficacy in the treatment of Gram-negative infections. However, resistance to cefiderocol has been reported in A. baumannii. Combination therapies, such as cefiderocol with avibactam or sulbactam, show reduced MICs against cefiderocol-non-susceptible strains with in vivo efficacy, although the outcomes can be complex and species-specific. In the present work, the molecular characterization of spontaneous cefiderocol-resistant variants, a CRAB strain displaying antagonism with sulbactam and an A. lwoffii strain showing antagonism with avibactam, were studied. The results reveal intriguing insights into the underlying mechanisms, including mutations affecting efflux pumps, transcriptional regulators, and iron homeostasis genes. Moreover, gene expression analysis reveals significant alterations in outer membrane proteins, iron homeostasis, and ß-lactamases, suggesting adaptive responses to selective pressure. Understanding these mechanisms is crucial for optimizing treatment strategies and preventing adverse clinical outcomes. This study highlights the importance of preemptively assessing drug synergies to navigate the challenges posed by antimicrobial resistance in CR-Acinetobacter infections.

Draft genome sequence of Lacticaseibacillus rhamnosus CRL 2244, a strain with strong killing effect on carbapenem-resistant Acinetobacter baumannii.

We report here a draft genome assembly of Lacticaseibacillus rhamnosus CRL 2244, recovered from wastewater in Argentina. The genome has a size of 2,898,100 bp, with G + C content of 46.73%. Comparative analysis reveals that its closest relative is L. rhamnosus 1.0320 (GCF_006151905.1), with an average nucleotide identity of 97.46%.

The patient perspective on vaccine uptake in adults with psoriasis and eczema.

Having a chronic disease is one of the most consistent factors associated with vaccine uptake for adults in the general population, but vaccination beliefs and behaviors specific to those with chronic skin diseases have not been explored. The objective of this study was to explore factors associated with vaccine uptake and barriers to vaccination in adults with psoriasis and eczema. Virtual, video-based semi-structured interviews were performed with adults who self-reported a diagnosis of psoriasis or eczema. Interviews explored themes around healthcare decision making, perceived risks/benefits to vaccination, barriers, and vaccine knowledge. Thematic analysis was used to analyze the data. Of 34 study participants, 25 participants (74%) were females and 9 (26%) were males, with a mean age of 50.8 years (SD: 16.4, range: 24-71 yrs). Half of participants (n = 17) had psoriasis, and half (n = 17) had eczema. Participants recognized both personal and societal benefits to vaccines. Common vaccination barriers identified were access to appointments, concerns about side effects, and misinformation. Physicians, friends/family, and media, including internet resources, were health information resources identified by patients. These results summarize the unique patient perspective around vaccine uptake in adults with eczema and psoriasis and represent an important first step in a multi-pronged approach to improve vaccination rates in adults with chronic skin diseases.

Seroprevalence of SARS-CoV-2 in 1186 Equids Presented to a Veterinary Medical Teaching Hospital in California from 2020 to 2022.

While some companion animals have been shown to be susceptible to SARS-CoV-2, their role in the COVID-19 pandemic has remained poorly investigated. Equids are susceptible to SARS-CoV-2 based on the similarity of the human ACE-2 receptor and reports of infection. Clinical disease and prevalence factors associated with SARS-CoV-2 infection in equids have not yet been investigated. The aim of this study was to determine the seroprevalence of SARS-CoV-2 and selected prevalence factors in 1186 equids presented for various conditions to a Veterinary Medical Teaching Hospital over a two-year period. Blood samples were tested for SARS-CoV-2 antibodies using an ELISA targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Further, selected prevalence factors (season, age, breed, sex, presenting complaint) were retrieved from the medical records. No information was available on whether the horses had come into contact with COVID-19-positive individuals. Among the study animals, 42/1186 (3.5%) horses had detectable SARS-CoV-2 antibodies. Amongst the prevalence factors investigated, only seasonality (spring) was associated with a greater frequency of seropositivity to SARS-CoV-2. Horses with medical and surgical complaints were more likely to test seropositive to SARS-CoV-2 compared to horses presented for routine health care procedures, suggesting more frequent and/or longer interactions with individuals with COVID-19. While horses can become infected with SARS-CoV-2 via the occasional spillover from COVID-19 individuals, clinical disease expression remains subclinical, making horses an unlikely contributor to the spread of SARS-CoV-2.

Reuben Friedman (1892-1956): Dermatologist, historian, and scabies enthusiast.

Reuben Friedman was a prominent physician, scholar, and historian whose work contributed significantly to the development of modern dermatology. He was born into a Russian immigrant family in the Northern Liberties section of Philadelphia, where he established his family and later opened his medical office. He graduated from Temple University School of Medicine, completed his internship at Philadelphia General Hospital, and pursued further training abroad. During the height of his career, Friedman was affiliated with the Philadelphia Skin and Cancer Hospital and served as a faculty member at Temple University School of Medicine. He was recognized internationally for his extensive work on scabies, penning four books, several monographs, and various presentations on its etiology and treatment. His final book, History of Dermatology in Philadelphia, recollects the evolution of dermatology in Philadelphia and numerous biographies of protagonists in the field.

Physician Perspectives on the Effect of Topical Steroid Costs on Patients and Proposed Solutions.

IMPORTANCE: Rising costs of topical steroids have increased overall health care and patient out-of-pocket costs while increasing administrative burden on dermatologists and office staff. OBJECTIVE: To explore factors affecting the decision-making process for dermatologists around topical steroid prescriptions, determine the association of insurance coverage and cost, and assess willingness to implement solutions to decrease out-of-pocket topical steroid costs for patients. DESIGN, SETTING, AND PARTICIPANTS: This qualitative study was conducted from June to November 2020 and used semistructured interviews of 16 dermatologists who reflected a mix of physicians in academic, nonacademic, and private practice until thematic saturation was reached. Each interview was independently coded by 2 researchers. Code frequency and interrater reliability were determined using NVIVO software. Data analysis was conducted from November 2020 to March 2021. MAIN OUTCOMES AND MEASURES: Factors influencing dermatologist decision-making around topical steroid selection, outcomes of unaffordable medications on patients, solution recommendations, and perspectives on a system to automatically substitute topical steroid for cheaper alternatives of the same class and vehicle. RESULTS: Of the 16 dermatologists, 8 (50.0%) were women, 8 (50.0%) were men, 1 (6.3%) was Asian, 2 (12.5%) were Latinx, and 12 (75.0%) were White. The interrater reliability ranged from κ = 0.86 to κ = 0.98, indicating excellent agreement. Most physicians (13 [81%]) thought about costs regularly when making choices about topical steroids. All physicians identified a scenario in which patients could not obtain medication based on cost. In these cases, 15 (94%) reported that they try to find an alternative medication by calling the pharmacist or insurance company. Despite a desire to consider cost at the time of prescribing, physicians reported not knowing medication costs before prescribing because of the variability of insurance coverage (15 [94%]), lack of transparency (12 [75%]), and fluctuating drug prices (12 [75%]). In addition to affecting patients, 14 physicians (88%) reported that a patient's inability to afford medications increases administrative burden. Physicians suggested that they were open to solutions that focused on increased cost transparency (10 [63%]) and improved electronic health record technologies. Furthermore, 14 (88%) were willing to use a system to allow the substitution of one topical steroid for another of the same class and vehicle. CONCLUSIONS AND RELEVANCE: The results of this qualitative study suggest that opacity around drug costs reduces access for patients and is followed by administrative stress for physicians and staff. Dermatologists are receptive to systems that provide greater transparency for drug costs or automate substitution of equivalent cheaper drugs for patients.

Disease Progression in Cutaneous Squamous Cell Carcinoma Patients With Satellitosis and In-transit Metastasis.

BACKGROUND/AIM: Satellitosis/in-transit metastasis (S-ITM) has prognostic value in melanoma and Merkel cell carcinoma, but is not incorporated into cutaneous squamous cell carcinoma (cSCC) staging. PATIENTS AND METHODS: From our IRB-approved registry, patients with high-risk cSCC, including patients with S-ITM, were identified. Univariate (UVA) and multivariate (MVA) analyses were performed to compare disease progression (DP) and overall survival (OS). Cumulative incidence of DP and OS analyses were performed using Fine-Gray and Kaplan-Meier methods, respectively. RESULTS: A total of 18 S-ITM subjects were compared to 247 high risk subjects including T3N0 (n=143), N1-N3 without extranodal extension (ENE) (n=56), N1-N3 with ENE (n=26) and M1 disease (n=22). Median follow up was 16.5 months. Three-year rates of DP were 22% for T3N0, 42% for S-ITM, 48% for T4 bone invasion, 50% for N1-N3 without extranodal extension (ENE), 53% for N1-N3 with ENE, and 66% for M1. Patients with S-ITM did not experience significantly worse DP compared to those with T3N0 (HR=1.96, 95%CI=0.8-4.9; p=0.14). CONCLUSION: Cutaneous SCC patients with S-ITM experienced outcomes similar to locally advanced non-metastatic cSCC patients. Larger studies are needed to guide incorporation into staging systems.

Center-Based Experiences Implementing Strategies to Reduce Risk of Horizontal Transmission of SARS-Cov-2: Potential for Compromise of Neonatal Microbiome Assemblage.

Perinatal transmission of COVID-19 is poorly understood and many neonatal intensive care units' (NICU) policies minimize mother-infant contact to prevent transmission. We present our unit's approach and ways it may impact neonatal microbiome acquisition. We attended COVID-19 positive mothers' deliveries from March-August 2020. Delayed cord clamping and skin-to-skin were avoided and infants were admitted to the NICU. No parents' visits were allowed and discharge was arranged with COVID-19 negative family members. Maternal breast milk was restricted in the NICU. All twenty-one infants tested negative at 24 and 48 hours and had average hospital stays of nine days. 40% of mothers expressed breastmilk and 60% of infants were discharged with COVID-19 negative caregivers. Extended hospital stays, no skin-to-skin contact, limited maternal milk use, and discharge to caregivers outside primary residences, potentially affect the neonatal microbiome. Future studies are warranted to explore how ours and other centers' similar policies influence this outcome.

Gene editing to induce FOXP3 expression in human CD4+ T cells leads to a stable regulatory phenotype and function.

Thymic regulatory T cells (tTregs) are potent inhibitors of autoreactive immune responses, and loss of tTreg function results in fatal autoimmune disease. Defects in tTreg number or function are also implicated in multiple autoimmune diseases, leading to growing interest in use of Treg as cell therapies to establish immune tolerance. Because tTregs are present at low numbers in circulating blood and may be challenging to purify and expand and also inherently defective in some subjects, we designed an alternative strategy to create autologous Treg-like cells from bulk CD4+ T cells. We used homology-directed repair (HDR)-based gene editing to enforce expression of FOXP3, the master transcription factor for tTreg Targeted insertion of a robust enhancer/promoter proximal to the first coding exon bypassed epigenetic silencing, permitting stable and robust expression of endogenous FOXP3. HDR-edited T cells, edTregs, manifested a transcriptional program leading to sustained expression of canonical markers and suppressive activity of tTreg Both human and murine edTregs mediated immunosuppression in vivo in models of inflammatory disease. Further, this engineering strategy permitted generation of antigen-specific edTreg with robust in vitro and in vivo functional activity. Last, edTreg could be enriched and expanded at scale using clinically relevant methods. Together, these findings suggest that edTreg production may permit broad future clinical application.

IL-2 enhances ex vivo-expanded regulatory T-cell persistence after adoptive transfer.

As regulatory T cell (Treg) adoptive therapy continues to develop clinically, there is a need to determine which immunomodulatory agents pair most compatibly with Tregs to enable persistence and stabilize suppressor function. Prior work has shown that mechanistic target of rapamycin inhibition can increase the stability of thymic Tregs. In this study, we investigated the transcriptomic signatures of ex vivo-expanded Tregs after adoptive transfer in the setting of clinically relevant immunosuppression using a nonhuman primate (NHP) model as a prelude to future transplant studies. Here, we found that adding interleukin-2 (IL-2) to rapamycin in vivo supported a logarithmic increase in the half-life of adoptively transferred carboxyfluorescein diacetate succinimidyl ester-labeled, autologous NHP Tregs, effectively doubling the number of cells in the peripheral blood Treg compartment compared with Treg infusion when rapamycin was given alone. Using single-cell transcriptomics, we found that transferred ex vivo-expanded Tregs initially exhibit a gene expression signature consistent with an activated state. Moreover, those cells with the highest levels of activation also expressed genes associated with p53-mediated apoptosis. In contrast, transferred Tregs interrogated at day +20 posttransfer demonstrated a gene signature more similar to published profiles of resting Tregs. Together, these preclinical data further support combining IL-2 and rapamycin in vivo as adjunctive therapy for ex vivo-expanded adoptively transferred Tregs and suggest that the activation status of ex vivo-expanded Tregs is critical to their persistence.

Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia.

There are hundreds of essential genes in multidrug-resistant bacterial genomes, but only a few of their products are exploited as antibacterial targets. An example is the electron transfer flavoprotein (ETF), which is required for growth and viability in Burkholderia cenocepacia. Here, we evaluated ETF as an antibiotic target for Burkholderia cepacia complex (Bcc). Depletion of the bacterial ETF during infection of Caenorhabditis elegans significantly extended survival of the nematodes, proving that ETF is essential for survival of B. cenocepacia in this host model. In spite of the arrest in respiration in ETF mutants, the inhibition of etf expression did not increase the formation of persister cells, when treated with high doses of ciprofloxacin or meropenem. To test if etf translation could be inhibited by RNA interference, antisense oligonucleotides that target the etfBA operon were synthesized. One antisense oligonucleotide was effective in inhibiting etfB translation in vitro but not in vivo, highlighting the challenge of reduced membrane permeability for the design of drugs against B. cenocepacia. This work contributes to the validation of ETF of B. cenocepacia as a target for antibacterial therapy and demonstrates the utility of a C. elegans liquid killing assay to validate gene essentiality in an in vivo infection model.