Women's Knowledge of Genomic Testing and Precision Medicine in Breast Cancer Treatment Decision-Making.

PURPOSE: To understand awareness of genetic and genomic testing, as well as decision-making, in women diagnosed with breast cancer. PARTICIPANTS & SETTING: 29 African American/Black and Latina/Hispanic women diagnosed with breast cancer. METHODOLOGIC APPROACH: A semistructured interview guide was used in focus groups conducted via videoconference. Transcripts were analyzed using thematic analysis. FINDINGS: Many of the women understood the concept of genetic testing to identify the BRCA1/BRCA2 variant, but none of them were aware of genomic testing and its implications for personalized medicine. Participants discussed provider and patient roles in treatment decision-making, identifying roles that the physician might play in treatment planning, from primary decision-maker to collaborator. IMPLICATIONS FOR NURSING: As the number of precision cancer treatments expands, patients must be able to comprehend the information provided to make informed decisions about their treatment. Providers should do a better job of explaining potential treatments so that patients feel they are part of the decision-making process. Addressing gaps in treatment access and uptake requires providers to prioritize patient engagement and understanding.

A cryptic oxidoreductase safeguards oxidative protein folding in Corynebacterium diphtheriae.

In many gram-positive Actinobacteria, including Actinomyces oris and Corynebacterium matruchotii, the conserved thiol-disulfide oxidoreductase MdbA that catalyzes oxidative folding of exported proteins is essential for bacterial viability by an unidentified mechanism. Intriguingly, in Corynebacterium diphtheriae, the deletion of mdbA blocks cell growth only at 37 °C but not at 30 °C, suggesting the presence of alternative oxidoreductase enzyme(s). By isolating spontaneous thermotolerant revertants of the mdbA mutant at 37 °C, we obtained genetic suppressors, all mapped to a single T-to-G mutation within the promoter region of tsdA, causing its elevated expression. Strikingly, increased expression of tsdA-via suppressor mutations or a constitutive promoter-rescues the pilus assembly and toxin production defects of this mutant, hence compensating for the loss of mdbA. Structural, genetic, and biochemical analyses demonstrated TsdA is a membrane-tethered thiol-disulfide oxidoreductase with a conserved CxxC motif that can substitute for MdbA in mediating oxidative folding of pilin and toxin substrates. Together with our observation that tsdA expression is upregulated at nonpermissive temperature (40 °C) in wild-type cells, we posit that TsdA has evolved as a compensatory thiol-disulfide oxidoreductase that safeguards oxidative protein folding in C. diphtheriae against thermal stress.

Phage Resistance Accompanies Reduced Fitness of Uropathogenic Escherichia coli in the Urinary Environment.

Urinary tract infection (UTI) is among the most common infections treated worldwide each year and is caused primarily by uropathogenic Escherichia coli (UPEC). Rising rates of antibiotic resistance among uropathogens have spurred a consideration of alternative treatment strategies, such as bacteriophage (phage) therapy; however, phage-bacterial interactions within the urinary environment are poorly defined. Here, we assess the activity of two phages, namely, HP3 and ES17, against clinical UPEC isolates using in vitro and in vivo models of UTI. In both bacteriologic medium and pooled human urine, we identified phage resistance arising within the first 6 to 8 h of coincubation. Whole-genome sequencing revealed that UPEC strains resistant to HP3 and ES17 harbored mutations in genes involved in lipopolysaccharide (LPS) biosynthesis. Phage-resistant strains displayed several in vitro phenotypes, including alterations to adherence to and invasion of human bladder epithelial HTB-9 cells and increased biofilm formation in some isolates. Interestingly, these phage-resistant UPEC isolates demonstrated reduced growth in pooled human urine, which could be partially rescued by nutrient supplementation and were more sensitive to several outer membrane-targeting antibiotics than parental strains. Additionally, phage-resistant UPEC isolates were attenuated in bladder colonization in a murine UTI model. In total, our findings suggest that while resistance to phages, such as HP3 and ES17, may arise readily in the urinary environment, phage resistance is accompanied by fitness costs which may render UPEC more susceptible to host immunity or antibiotics. IMPORTANCE UTI is one of the most common causes of outpatient antibiotic use, and rising antibiotic resistance threatens the ability to control UTI unless alternative treatments are developed. Bacteriophage (phage) therapy is gaining renewed interest; however, much like with antibiotics, bacteria can readily become resistant to phages. For successful UTI treatment, we must predict how bacteria will evade killing by phage and identify the downstream consequences of phage resistance during bacterial infection. In our current study, we found that while phage-resistant bacteria quickly emerged in vitro, these bacteria were less capable of growing in human urine and colonizing the murine bladder. These results suggest that phage therapy poses a viable UTI treatment if phage resistance confers fitness costs for the uropathogen. These results have implications for developing cocktails of phage with multiple different bacterial targets, of which each is evaded only at the cost of bacterial fitness.

Corrigendum: Development of phage cocktails to treat E. coli catheter-associated urinary tract infection and associated biofilms.

[This corrects the article DOI: 10.3389/fmicb.2022.796132.].

Development of Phage Cocktails to Treat E. coli Catheter-Associated Urinary Tract Infection and Associated Biofilms.

High rates of antimicrobial resistance and formation of biofilms makes treatment of Escherichia coli catheter-associated urinary tract infections (CAUTI) particularly challenging. CAUTI affect 1 million patients per year in the United States and are associated with morbidity and mortality, particularly as an etiology for sepsis. Phage have been proposed as a potential therapeutic option. Here, we report the development of phage cocktails that lyse contemporary E. coli strains isolated from the urine of patients with spinal cord injury (SCI) and display strong biofilm-forming properties. We characterized E. coli phage against biofilms in two in vitro CAUTI models. Biofilm viability was measured by an MTT assay that determines cell metabolic activity and by quantification of colony forming units. Nine phage decreased cell viability by >80% when added individually to biofilms of two E. coli strains in human urine. A phage cocktail comprising six phage lyses 82% of the strains in our E. coli library and is highly effective against young and old biofilms and against biofilms on silicon catheter materials. Using antibiotics together with our phage cocktail prevented or decreased emergence of E. coli resistant to phage in human urine. We created an anti-biofilm phage cocktail with broad host range against E. coli strains isolated from urine. These phage cocktails may have therapeutic potential against CAUTI.

A cell wall-anchored glycoprotein confers resistance to cation stress in Actinomyces oris biofilms.

Actinomyces oris plays an important role in oral biofilm development. Like many gram-positive bacteria, A. oris produces a sizable number of surface proteins that are anchored to bacterial peptidoglycan by a conserved transpeptidase named the housekeeping sortase SrtA; however, the biological role of many A. oris surface proteins in biofilm formation is largely unknown. Here, we report that the glycoprotein GspA-a genetic suppressor of srtA deletion lethality-not only promotes biofilm formation but also maintains cell membrane integrity under cation stress. In comparison to wild-type cells, under elevated concentrations of mono- and divalent cations the formation of mono- and multi-species biofilms by mutant cells devoid of gspA was significantly diminished, although planktonic growth of both cell types in the presence of cations was indistinguishable. Because gspA overexpression is lethal to cells lacking gspA and srtA, we performed a genetic screen to identify GspA determinants involving cell viability. DNA sequencing and biochemical characterizations of viable clones revealed that mutations of two critical cysteine residues and a serine residue severely affected GspA glycosylation and biofilm formation. Furthermore, mutant cells lacking gspA were markedly sensitive to sodium dodecyl sulfate, a detergent that solubilizes the cytoplasmic membranes, suggesting the cell envelope of the gspA mutant was altered. Consistent with this observation, the gspA mutant exhibited increased membrane permeability, independent of GspA glycosylation, compared to the wild-type strain. Altogether, the results support the notion that the cell wall-anchored glycoprotein GspA provides a defense mechanism against cation stress in biofilm development promoted by A. oris.

Electron Transport Chain Is Biochemically Linked to Pilus Assembly Required for Polymicrobial Interactions and Biofilm Formation in the Gram-Positive Actinobacterium Actinomyces oris.

The Gram-positive actinobacteria Actinomyces spp. are key colonizers in the development of oral biofilms due to the inherent ability of Actinomyces to adhere to receptor polysaccharides on the surface of oral streptococci and host cells. This receptor-dependent bacterial interaction, or coaggregation, requires a unique sortase-catalyzed pilus consisting of the pilus shaft FimA and the coaggregation factor CafA forming the pilus tip. While the essential role of the sortase machine SrtC2 in pilus assembly, biofilm formation, and coaggregation has been established, little is known about trans-acting factors contributing to these processes. We report here a large-scale Tn5 transposon screen for mutants defective in Actinomyces oris coaggregation with Streptococcus oralis We obtained 33 independent clones, 13 of which completely failed to aggregate with S. oralis, and the remainder of which exhibited a range of phenotypes from severely to weakly defective coaggregation. The former had Tn5 insertions in fimA, cafA, or srtC2, as expected; the latter were mapped to genes coding for uncharacterized proteins and various nuo genes encoding the NADH dehydrogenase subunits. Electron microscopy and biochemical analyses of mutants with nonpolar deletions of nuo genes and ubiE, a menaquinone C-methyltransferase-encoding gene downstream of the nuo locus, confirmed the pilus and coaggregation defects. Both nuoA and ubiE mutants were defective in oxidation of MdbA, the major oxidoreductase required for oxidative folding of pilus proteins. Furthermore, supplementation of the ubiE mutant with exogenous menaquinone-4 rescued the cell growth and pilus defects. Altogether, we propose that the A. oris electron transport chain is biochemically linked to pilus assembly via oxidative protein folding.IMPORTANCE The Gram-positive actinobacterium A. oris expresses adhesive pili, or fimbriae, that are essential to biofilm formation and Actinomyces interactions with other bacteria, termed coaggregation. While the critical role of the conserved sortase machine in pilus assembly and the disulfide bond-forming catalyst MdbA in oxidative folding of pilins has been established, little is known about other trans-acting factors involved in these processes. Using a Tn5 transposon screen for mutants defective in coaggregation with Streptococcus oralis, we found that genetic disruption of the NADH dehydrogenase and menaquinone biosynthesis detrimentally alters pilus assembly. Further biochemical characterizations determined that menaquinone is important for reactivation of MdbA. This study supports the notion that the electron transport chain is biochemically linked to pilus assembly in A. oris via oxidative folding of pilin precursors.

Antioxidant Defenses of Francisella tularensis Modulate Macrophage Function and Production of Proinflammatory Cytokines.

Francisella tularensis, the causative agent of a fatal human disease known as tularemia, has been used in the bioweapon programs of several countries in the past, and now it is considered a potential bioterror agent. Extreme infectivity and virulence of F. tularensis is due to its ability to evade immune detection and to suppress the host's innate immune responses. However, Francisella-encoded factors and mechanisms responsible for causing immune suppression are not completely understood. Macrophages and neutrophils generate reactive oxygen species (ROS)/reactive nitrogen species as a defense mechanism for the clearance of phagocytosed microorganisms. ROS serve a dual role; at high concentrations they act as microbicidal effector molecules that destroy intracellular pathogens, and at low concentrations they serve as secondary signaling messengers that regulate the expression of various inflammatory mediators. We hypothesized that the antioxidant defenses of F. tularensis maintain redox homeostasis in infected macrophages to prevent activation of redox-sensitive signaling components that ultimately result in suppression of pro-inflammatory cytokine production and macrophage microbicidal activity. We demonstrate that antioxidant enzymes of F. tularensis prevent the activation of redox-sensitive MAPK signaling components, NF-κB signaling, and the production of pro-inflammatory cytokines by inhibiting the accumulation of ROS in infected macrophages. We also report that F. tularensis inhibits ROS-dependent autophagy to promote its intramacrophage survival. Collectively, this study reveals novel pathogenic mechanisms adopted by F. tularensis to modulate macrophage innate immune functions to create an environment permissive for its intracellular survival and growth.

Genotipificación de Acinetobacter baumannii multi-resistente aislado en el hospital Dr. Domingo Luciani de caracas / Genotypification of multiresistant Acinetobacter baumannii isolated in the Dr. Domingo Luciani Hospital of caracas

Las técnicas de genotipificación tienen un rol fundamental en el estudio de las infecciones nosocomiales. Las infecciones nosocomiales son producidas principalmente por microorganismos que son resistentes a los antimicrobianos, que por lo general han sido seleccionados por el uso inadecuado de la terapia antimicrobiana. Entre las especies que causan frecuentemente este tipo de infecciones se encuentra A. baumannii multi-resistente. En esta investigación se planteó genotipificar mediante las técnicas ERIC-PCR y REP-PCR 19 cepas de A. baumannii multi-resistente aisladas en el hospital Dr. Domingo Luciani de Caracas. La confirmación molecular de la especie A. baumannii se realizó mediante la detección de la oxacilinasa OXA 51 por PCR, el 100% de los aislados incluidos en el estudio resultaron positivos para la detección del gen blaOXA-51-Like. La susceptibilidad antimicrobiana y la detección fenotípica de mecanismos de resistencia se efectuaron de acuerdo a las normas de la CLSI 2009. Se determinó policlonalidad en los 19 aislados de A. baumannii, con el predominio de cuatro clones en la Unidad de Terapia Intensiva de Adultos y el área de Hospitalización del Hospital Dr. Domingo Luciani de Caracas. La correlación de los datos epidemiológicos con las características de la resistencia y la información molecular de cada una de las muestras permitió identificar dos patrones de infección: infecciones de origen endógeno, las cuales se caracterizaron por la diversidad genética de los aislamientos, e infecciones cruzadas, debido al hallazgo de cepas estrechamente relacionadas en espacios cercano o distantes del centro de salud. Se demostró que ERIC-PCR y REP-PCR bajo las condiciones estandarizadas en este estudio son técnicas confiables desde el punto de vista de la estabilidad de los marcadores moleculares y la reproducibilidad para caracterizar brotes ocasionados por A. baumannii, considerándose la técnica REP-PCR más adecuada para estudios de genotipificación...

The genotypification techniques have a fundamental role in the study of nosocomial infections. These infections are produced principally by microorganisms that are antimicrobial resistant, that have benn selected by the inadequate use of antimicrobial therapy. Between the species that frequently cause these type of infections is the A baumannii multi-resistant. In this investigation we established to genotypificate by ERIC-PCR y REP-PCR techniques 19 strains of A baumannii multi-resitant isolated in the Dr. Domingo Luciani Hospital of Caracas. The molecular confirmation of the species was realized by the detection of the oxacilianse OXA 51 by PCR. 100% of the isolates included in the study resulted positive for the gen bla OXA-51-Like. The antimocrobial susceptibility and the phenotypic detection of resistance mechanism were done according the CLSI 2009 normative. We determined policlonality on the 19 isolates of A. baumannii, with the predominance of 4 clones in the Intensive Therapy unit and the hospitalization area of the hospital. The correlation of the epidemiological data with the resistance characteristics and the molecular information of each sample allowed us to identificate two patterns of infections: endogen origin infection, which was charaterized by the genetic diversity of the isolates and cross infections, due to the finding of strains closely related in spaces near o distant ffrom the health center. We demostrated that ERIC-PCR and REP-PCR under standarized conditions in this study are good techiques fron the point of view of the stability of the molecular markers and the reproducibility to characterize outbreaks occasioned by A. baumannii, consideratin the REP-PCR technique, the most adequate for genotypification of this strain.

Modificaciones del flujo expiratorio máximo en el tratamiento del asma bronquial con intal y ketotifeno

Introducción: Los estudios de la función pulmonar son esenciales para el diagnóstico, clasificación y tratamiento del asma bronquial y dentro de ellos la medición del flujo expiratorio máximo proporciona un valor cuantitativo de la obstrucción de las vías aéreas. Objetivo : Precisar las modificaciones del flujo expiratorio máximo en el tratamiento intercrisis del asma bronquial con intal y ketotifeno. Métodos: Se realizó un estudio en dos etapas, la primera descriptiva en la que se incluyeron los pacientes de 15 años y más con diagnóstico de asma bronquial y pertenecientes al Consultorio Médico de Familia #26 del Policlínico   área V del Municipio Cienfuegos. La muestra quedó constituida por 37 pacientes, a los que se les aplicó un formulario de datos donde se incluía la edad, sexo, características clínicas de su enfermedad y el tratamiento en ese momento. En la segunda etapa se crearon dos grupos seleccionados por el método aleatorio simple. El primero recibió tratamiento con intal spray (4 aplicaciones/día) y el segundo con ketotifeno (tab. 1 mg. /2tab al día). Se realizaron mediciones del flujo expiratorio máximo a los tres, seis, nueve y doce meses de implementado el tratamiento. Resultados: P revalecieron las edades de 15 a 24 años y de 25 a 34 años y el sexo femenino, el salbutamol spray fue el más utilizado en los tratamientos anteriores, inicialmente el mayor número de asmáticos fue clasificado como moderados y al finalizar el 12 mo mes el 72.9 porciento del total de la muestra se comportaba como ligeros; con ambos tratamientos se mejoraron los valores del flujo expiratorio máximo, aunque el grupo de pacientes que recibió tratamiento con intal mostró una mejoría mucho más rápida. Conclusión: Aquellos pacientes que utilizaron intal tuvieron una elevacián más rápida del flujo expiratorio máximo