11 research outputs found

    Tuning the decay of sound in a viscous metamaterial

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    Authors of the article use analytical results for viscous dissipation in phononic crystals to calculate the decay coefficient of a sound wave propagating at low frequencies through a two-dimensional phononic crystal with a viscous fluid background. They claim that the decay coefficient exhibits dependence on the direction of propagation; that is, a homogenized phononic crystal behaves like an anisotropic viscous fluid

    Species identification of Enterococcus

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    Objetivo: Aquí, evaluamos el rendimiento de dos sistemas comerciales de EM MALDI ‐ TOF y tres sistemas basados en bioquímicos y los comparamos con WGS como el estándar de oro para identificar cepas de enterococos resistentes a la vancomicina (ERV). Métodos: Se incluyeron un total de 87 aislamientos clínicos de ERV. Los espectrómetros de masas fueron el sistema Microflex con software Biotyper 3.1 y el sistema Vitek MS. Los sistemas basados en bioquímicos incluyeron los sistemas Vitek 2, Phoenix y MicroScan WalkAway. La WGS se realizó en un instrumento Illumina MiSeq utilizando el kit de reactivos MiSeq v3. La resistencia a la vancomicina se determinó según los criterios de CLSI. Resultados: Entre los 87 VRE, 71 y 16 fueron identificados como Enterococcus faecium y Enterococcus faecalis por WGS. Los 71 E faecium fueron identificados correctamente por ambos espectrómetros de masas, así como por los instrumentos Vitek 2 y Phoenix. Sin embargo, el sistema MicroScan solo identificó correctamente 51 aislados de E. faecium . La identificación errónea más frecuente fue Enterococcus casseliflavus (n = 20). Para E. faecium resistente a la vancomicina , el sistema Microflex Biotyper tuvo la mayor sensibilidad (85,54%) y todos los instrumentos (excepto el Microscan) tuvieron una especificidad y un VPP del 100%. Hasta el 87% de E. faecalis los aislamientos fueron identificados erróneamente por VITEK MS y VITEK2, 81% por Microscan y Phoenix, y 75% por Bruker biotyper. Conclusión: A medida que la cobertura de la base de datos de secuencias de tipo cepa-genoma continúa creciendo y el costo de la secuenciación del ADN continúa disminuyendo, la identificación basada en el genoma puede ser una herramienta útil para los laboratorios de diagnóstico, con su precisión superior incluso sobre MALDI-TOF y las operaciones basadas en bases de datos .Aim: Here, we evaluated the performance of two commercial MALDI-TOF MS systems and three biochemical-based systems and compared them to WGS as the gold standard for identifying isolates of vancomycin-resistant enterococci (VRE). Methods: A total of 87 VRE clinical isolates were included. The mass spectrometers were the Microflex system with Biotyper software 3.1 and the Vitek MS system. The biochemical-based systems included the Vitek 2, Phoenix, and MicroScan WalkAway systems. WGS was performed on an Illumina MiSeq instrument using the MiSeq v3 reagent kit. Vancomycin resistance was determined according to CLSI criteria. Results: Among the 87 VRE, 71 and 16 were identified as Enterococcus faecium and Enterococcus faecalis by WGS. All 71 E faecium were correctly identified by both mass spectrometers, as well as the Vitek 2 and Phoenix instruments. However, only 51 E faecium isolates were correctly identified by the MicroScan system. The most frequent misidentification was Enterococcus casseliflavus (n = 20). For vancomycin-resistant E faecium, the Microflex Biotyper system had the highest sensitivity (85.54%), and all instruments (except for the Microscan) had a 100% specificity and PPV. Up to 87% of E faecalis isolates were misidentified by VITEK MS and VITEK2, 81% by Microscan and Phoenix, and 75% by Bruker biotyper. Conclusion: As the coverage of type strain-genome sequence database continues to grow and the cost of DNA sequencing continues to decrease, genome-based identification can be a useful tool for diagnostic laboratories, with its superior accuracy even over MALDI-TOF and database-driven operations

    Clinical and Immunologic Efficacy of the Recombinant Adenovirus Type-5-Vectored (CanSino Bio) Vaccine in University Professors during the COVID-19 Delta Wave

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    Information regarding the efficacy of the recombinant adenovirus type-5-vectored (CanSino Bio) vaccine against the COVID-19 disease in a real-life setting is limited. A retrospective cohort study was carried out in the teaching university community of the metropolitan area of Monterrey, Mexico, through a four-section survey, and during the COVID-19 delta wave. Determination of IgG antibodies against SARS-CoV-2 spike (S) protein was performed in a subset of participants vaccinated with CanSino Bio. A total of 7468 teachers responded to the survey, and 6695 of them were fully vaccinated. Of those, 72.7% had CanSino Bio, 10.3% Pfizer, 8.4% AstraZeneca, 1.2% Moderna, and 2.7% others. Symptomatic breakthrough infections were recorded in those vaccinated with CanSino Bio (4.1%), AstraZeneca (2.1%), and Pfizer (2.2%). No difference was found between CanSino Bio and other vaccines regarding hospitalization, the need for mechanical ventilation, and death. For CanSino Bio recipients, anti-S antibodies were >50 AU/mL in 73.2%. In conclusion, primary breakthrough symptomatic infections were higher in the CanSino vaccinated group compared to other brands. Individuals with a previous infection had higher antibody levels than those who were reinfected and without infection. A boosted dose of CanSino is recommended for those individuals without a previous infection

    Prevalence of SARS-CoV-2 Variants of Concern and Variants of Interest in COVID-19 Breakthrough Infections in a Hospital in Monterrey, Mexico

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    SARS-CoV-2 variants of concern (VOCs) or of interest (VOIs) causing vaccine breakthrough infections pose an increased risk to worldwide public health. An observational case-control study was performed of SARS-CoV-2 vaccine breakthrough infections in hospitalized or ambulatory patients in Monterrey, Mexico, from April through August 2021. Vaccination breakthrough was defined as a SARS-CoV-2 infection that occurred any time after 7 days of inoculation with partial (e.g., first dose of two-dose vaccines) or complete immunization (e.g., second dose of two-dose vaccines or single-dose vaccine, accordingly). Case group patients (n = 53) had partial or complete vaccination schemes with CanSino (45%), Sinovac (19%), Pfizer/BioNTech (15%), and AstraZeneca/Oxford (15%). CanSino was administered most frequently in ambulatory patients (p < 0.01). The control group (n = 19) received no COVID-19 vaccines. Among SARS-CoV-2 variants detected by whole-genome sequencing, VOC Delta B.1.617.2 predominated in vaccinated ambulatory patients (p < 0.01) and AY.4 in hospitalized patients (p = 0.04); VOI Mu B.1.621 was detected in four (7.55%) vaccinated patients. SARS-CoV-2 breakthrough infections in our hospital occurred mostly in patients vaccinated with CanSino due to the higher prevalence of CanSino vaccine administration in our population. These patients developed mild COVID-19 symptoms not requiring hospitalization. The significance of this study lies on the detection of SARS-CoV-2 variants compromising the efficacy of local immunization therapies in Monterrey, Mexico

    Metagenomic Sequencing of Monkeypox Virus, Northern Mexico

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    Monkeypox virus (MPXV) has gained interest because of a multicountry outbreak of mpox (formerly monkeypox) cases with no epidemiologic link to MPXV-endemic regions. We sequenced the complete genome of MPXV isolated from a patient in northern Mexico. Phylogenetic analysis grouped the virus with isolates from Germany
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