Abstract
A nested case-control study among 137 nursing home residents who did not receive antimicrobials, of whom 44 acquired a multidrug-resistant organism, was performed. Risk factors for ...acquisition included gastrointestinal medications that affect the gut microbiome, number of visits from healthcare workers, pressure ulcers, and not residing in a dementia unit.
Abstract
Background
Residents of nursing homes (NH) are frequently exposed to antimicrobials and constitute a reservoir of multidrug-resistant organisms (MDRO). Microbiome dysbiosis has been ...associated with adverse clinical outcomes including MDRO colonization and infection. This study aimed to characterize specific features in the fecal microbiome (microbial disruption indices) predicting MDRO acquisition in residents of NH.
Methods
Residents in 35 NH from the Boston area, exposed to antimicrobials, were included in the study. Demographic and clinical characteristics, and rectal swabs were collected every three months for up to 12 months or until death to determine MDRO acquisition (negative baseline swab and at least one subsequent swab positive for MDRO). Rectal specimens were screened for MDRO by using conventional cultures. Additionally, the V4 region of the 16S rRNA gene was sequenced for assessing the fecal microbiome (Illumina MiSeq platform). Filtering, dereplication, sample inference, chimera checking, and merging of pair-end reads were performed using DADA2. The exploratory and inferential analyses were done using phyloseq. Fecal microbial diversity and composition was compared between patients that acquired MDRO or not.
Results
A total of 80 residents had at least two serial rectal samples and were exposed to antimicrobials. Among them, 28 (35%) acquired MDRO. Microbial diversity (Shannon index) was similar between those that acquired MDRO or not (MDRO+ and MDRO-, respectively). The β diversity analysis (UniFrac distances) did not show specific sample clustering according to MDRO status (Figures 1 and 2). The analysis of differentially abundant features showed higher relative abundance of Akkermansia muciniphila among MDRO- patients, whereas Blautia spp. was more abundant among those that acquired MDRO (Figure 3).
Conclusion
Differential abundance of key bacterial taxa, such as Akkermansia muciniphila and Blautia spp. may be future biomarkers predictive of MDRO acquisition. Identification and standardization of microbial disruption indices may provide important data to guide future innovative public health strategies aimed at limiting MDRO acquisition and dissemination.
Disclosures
J. Ugalde, uBiome: Employee, Salary.
OBJECTIVE To characterize the microbial disruption indices of hospitalized patients to predict colonization with multidrug-resistant organisms (MDROs). DESIGN A cross-sectional survey of the fecal ...microbiome was conducted in a tertiary referral, acute-care hospital in Boston, Massachusetts. PARTICIPANTS The study population consisted of adult patients hospitalized in general medical/surgical wards. METHODS Rectal swabs were obtained from patients within 48 hours of hospital admission and screened for MDRO colonization using conventional culture techniques. The V4 region of the 16S rRNA gene was sequenced to assess the fecal microbiome. Microbial diversity and composition, as well as the functional potential of the microbial communities present in fecal samples, were compared between patients with and without MDRO colonization. RESULTS A total of 44 patients were included in the study, of whom 11 (25%) were colonized with at least 1 MDRO. Reduced microbial diversity and high abundance of metabolic pathways associated with multidrug-resistance mechanisms characterized the fecal microbiome of patients colonized with MDRO at hospital admission. CONCLUSIONS Our data suggest that microbial disruption indices may be key to predicting MDRO colonization and could provide novel infection control approaches. Infect Control Hosp Epidemiol 2017;38:1312-1318.
Abstract
Background
Carbapenem resistance (CR) in Klebsiella pneumoniae is most frequently mediated by the production of carbapenemases. However, non-carbapenemase-producing K. pneumoniae ...(non-CP-Kpn) have been well documented. Overexpression of narrow β-lactamases can play an important role in the development of CR in the absence of carbapenemases. Here, we investigated the role of avibactam, a potent β-lactamase inhibitor, in preventing the in vitro development of CR in a non-CP-Kpn.
Methods
We used SCL-1, a non-CP-Kpn strain recovered from the bloodstream of a patient that developed CR in vivo during treatment with imipenem (IMI). SCL-1 was exposed to serial passages of increasing concentrations of IMI alone 0.25-16 μg/mL or in combination with avibactam (IMI-AVI) during 8 days. In the case of IMI-AVI, the concentration of AVI was fixed at 4 μg/mL. Evolution assays were performed in triplicate and considered 3 independent evolutionary lines (ELs). MICs at each time-point were measured to IMI and IMI-AVI by broth microdilution as per CLSI. Growth curves of SCL-1 and evolved strains were performed to assess fitness. The expression levels of narrow spectrum β-lactamases blaOXA-1,blaOXA-10, and of the ESBL blaCTX-M-15 were measured by RT-qPCR.
Results
In vitro exposure to IMI led to CR, with the MICs increasing from 0.5 μg/mL to 8 μg/mL in all 3 ELs. In contrast, all ELs exposed to IMI-AVI remained fully susceptible to IMI after 8 days, with a final MIC of 1 μg/mL. In addition, the MIC to IMI of the evolved, IMI-resistant strains, in the presence of AVI (4 μg/mL) dropped from 8 to 1 μg/mL. Growth curves revealed that IMI-resistant strains evolved in IMI alone exhibited a growth defect as compared to both SCL-1 and the susceptible strains evolved in IMI-AVI. Finally, compared to the SCL-1, the expression level of blaOXA-1 was significantly increased (p< 0.05) in all evolved isolates that developed IMI resistance (MIC=8 μg/mL). No significant changes were observed in the expression of blaOXA-10 and blaCTX-M-15 (Figure 1).Figure 1.RT-qPCR analysis of β-lactamase gene transcript levels for SCL-1 and evolutive lines (A and B). Data shown are individual data points with mean±SD superimposed.
Conclusion
Our findings suggest that the addition of AVI can prevent the in vitro development of IMI resistance in non-CP-Kpn. Our results have important implications for the clinical use of AVI as a strategy to combat CR in non-CP-Kpn infections.
Disclosures
All Authors: No reported disclosures
Abstract
Background
Carbapenem-resistant Enterobacterales (CRE) are a major public health threat, largely due to the presence of carbapenemases, which are globally disseminated in mobile genetic ...elements. The emergence of CRE carrying multiple carbapenemases has been reported in several countries, particularly after the COVID-19 pandemic. In this study, we report the emergence of dual-producing CRE (DP-CRE) in Chile and provide a phenotipic and genomic characterization using whole-genome sequencing (WGS).
Methods
We evaluated the presence of carbapenemase in a total of 1367 CRE isolates recovered from invasive infections in 11 healthcare centers since 2018. Among them, 9 DP-CRE were detected and included in this report. Antimicrobial susceptibility was tested by broth microdilution and disk diffusion methods (CLSI, 2023), while blaKPC, blaVIM, blaIMP and blaNDM genes were detected by PCR. WGS was carried out using short and long reads (Illumina and Oxford Nanopore) and hybrid assemblies were performed.
Results
All 9 DP-CRE identified were recovered between November 2021 and June 2022 from 3 healthcare centers of a single city. In terms of species, 6 were identified as E. coli, one isolate of K. pneumoniae, one K. oxytoca and one C. freundii. All DP-CRE identified carried the combination of blaKPC and blaNDM. Genomic analyses confirmed all but one isolate carried blaKPC-2 and blaNDM-7. The remaining genome belonged to a K. pneumoniae that harboured blaKPC-3 and blaNDM-7. All 9 isolates exhibited resistance to all β-lactams, including carbapenems, aztreonam (ATM), cephalosporins and β-lactam/β-lactamase inhibators. Cefiderocol (FDC) was the only compound active against all the isolates. Also, all the DP-CRE became susceptible to ATM when combined with ceftazidime/avibactam (CZA). Hybrid assemblies revealed that blaKPC and blaNDM were harboured on independent plasmids (∼58,900 bp and ∼41,100 bp, respectively) as shown in Figure 1.
Conclusion
To the best of our knowledge, this is the first report of the emergence of DP-CRE in Chile after COVID-19 pandemic. Our results highlight the relevance of active surveillance of multidrug-resistance pathogens. FDC and CZA/ATM were the only compounds that remained active in vitro against these pathogens.
Disclosures
All Authors: No reported disclosures
Introducción: Bocavirus humano (HBoV) es un nuevo parvovirus encontrado en niños con infecciones respiratorias agudas (IRA). Objetivos: Describir la epidemiología y perfil clínico en niños < 5 años ...con IRA, comparando aquellos con HBoV como único agente identificado, con los que tenían co-infección con otro virus respiratorio. Además se evaluó su prevalencia en niños asintomáticos, y se realizó análisis filogenético. Materiales y Métodos: Se investigó la presencia de HBoV, por medio de reacción de polimerasa en cadena, en muestras de secreción nasofaríngea obtenida en niños con IRA y en controles asintomáticos, entre 2007 y 2008. Resultados: Se detectó HBoV en 79 (21,8%) de 362 muestras obtenidas en pacientes con IRA. En 60/79 (76%), se demostró co-infección. Los síntomas más frecuentes fueron tos, fiebre y rinorrea. Los pacientes con HBoV como único agente identificado mostraron frecuencias significativamente menores de dificultad respiratoria, requerimiento de oxígeno y hospitalización, comparado con los co-infectados. HBoV se detectó en 6/16 (37,5%) muestras de niños asintomáticos. El análisis filogenético de las cepas chilenas demuestra estrecha relación con las cepas originales. Conclusiones: HBoV está presente en niños chilenos con IRA y asintomáticos. La gravedad de la enfermedad fue mayor en el grupo con co-infección.
Resumen Introducción: El uso de antimicrobianos se asocia a efectos laterales como alergias, reacciones adversas específicas y emergencia de resistencia antimicrobiana. Resulta fundamental una ...comunicación de riesgo efectiva a la población general sobre su utilidad y potenciales problemas. Experiencias internacionales revelan un bajo grado de conocimiento en la comunidad en países sin políticas educativas dirigidas, lo que mejora tras su implementación; a nivel regional y nacional existen escasas publicaciones al respecto. Objetivo: Describir el grado de conocimiento y conductas sobre el uso de antimicrobianos en adultos de Santiago de Chile. Métodos: Estudio transversal realizado mediante una encuesta a adultos en Santiago de Chile, evaluando cuatro aspectos sobre antimicrobianos: conocimiento, uso reciente, conductas sobre su uso y nociones sobre resistencia antimicrobiana. Resultados: Se encuestaron 300 personas entre 18 y 81 años (tres fueron descartadas posteriormente), siendo 75% de ellas menores de 45 años. Un 65% de los encuestados cree que los antibióticos antimicrobianos son activos frente a virus, 51% cree que sirven para tratar el resfrío común y 32% los ha utilizado sin receta. Un 51% ha escuchado el término resistencia antimicrobiana y 33% conoce su definición correcta. Conclusión: El conocimiento sobre la utilidad y problemas de los antimicrobianos en población chilena es deficiente, lo que podría favorecer su uso inapropiado.
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