Publications by authors named "Rechkina E"

We evaluated the performance of rapid antigen (RAg) and antibody (RAb) microfluidic diagnostics with serial sampling of 71 participants at 6 visits over 2 months following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Rapid tests showed strong agreement with laboratory references (κAg = 81.0%; κAb = 87.

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Background: Guidelines for SARS-CoV-2 have relied on limited data on duration of viral infectiousness and correlation with COVID-19 symptoms and diagnostic testing.

Methods: We enrolled ambulatory adults with acute SARS-CoV-2 infection and performed serial measurements of COVID-19 symptoms, nasal swab viral RNA, nucleocapsid (N) and spike (S) antigens, and replication-competent SARS-CoV-2 by viral growth in culture. We determined average time from symptom onset to a first negative test result and estimated risk of infectiousness, as defined by positive viral growth in culture.

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Article Synopsis
  • A randomized clinical trial was conducted in Kenya to evaluate the efficacy of single-dose nonavalent and bivalent HPV vaccines against a meningococcal vaccine among women aged 15 to 20.
  • The results indicated that both the nonavalent and bivalent HPV vaccines had very high efficacy rates (97.5%) in preventing persistent infections of HPV types 16 and 18, while significantly fewer infections occurred in the HPV vaccine groups compared to the meningococcal vaccine group.
  • Overall, the study supports the potential for single-dose HPV vaccination to simplify vaccination processes and decrease healthcare costs while maintaining strong protective effects against targeted HPV infections.
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  • The study compares different swab types and collection sites for testing SARS-CoV-2, focusing on the effectiveness of self-collected swabs from the anterior nares and tongue compared to standard nurse-collected nasopharyngeal swabs.
  • Results show that anterior nares swabs had higher diagnostic sensitivity using RT-PCR and antigen testing than tongue swabs, with sensitivities of 91-100% against viral culture.
  • The findings suggest that self-collection of anterior nares specimens could serve as a viable alternative for SARS-CoV-2 testing in certain situations.
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Background: HPV infection is the primary cause of cervical cancer, a leading cause of cancer among women in Kenya and many sub-Saharan African countries. High coverage of HPV vaccination is a World Health Organization priority to eliminate cervical cancer globally, but vaccine supply and logistics limit widespread implementation of the current two or three dose HPV vaccine schedule.

Methods: We are conducting an individual randomized controlled trial to evaluate whether a single dose of the bivalent (HPV 16/18) or nonavalent (HPV 16/18/31/33/45/52/58/6/11) HPV vaccine prevents persistent HPV infection, a surrogate marker for precancerous lesions and cervical cancer.

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We report that there is a recent global expansion of numerous independent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with mutation L452R in the receptor-binding domain (RBD) of the spike protein. The massive emergence of L452R variants was first linked to lineage B.1.

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The recent rise in mutational variants of SARS-CoV-2, especially with changes in the Spike protein, is of significant concern due to the potential ability for these mutations to increase viral infectivity, virulence and/or ability to escape protective antibodies. Here, we investigated genetic variations in a 414-583 amino acid region of the Spike protein, partially encompassing the ACE2 receptor-binding domain (RBD), across a subset of 570 nasopharyngeal samples isolated between April 2020 and February 2021, from Washington, California, Arizona, Colorado, Minnesota and Illinois. We found that samples isolated since November have an increased number of amino acid mutations in the region, with L452R being the dominant mutation.

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We report that fluoroquinolone-resistant Escherichia coli are found in feces of 8.8% of healthy women, with most bacteria belonging to pandemic multidrug-resistant ST131-H30R or ST1193 clonal groups. Moreover, these highly uropathogenic clonal groups demonstrate an especially prolonged gut persistence and high rate of bacteriuria without documented urinary tract infection.

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We describe the rapid and ongoing emergence across multiple US cities of a new multidrug-resistant Escherichia coli clone-sequence type (ST) 1193-resistant to fluoroquinolones (100%), trimethoprim-sulfamethoxazole (55%), and tetracycline (53%). ST1193 is associated with younger adults (age <40 years) and currently comprises a quarter of fluoroquinolone-resistant clinical E. coli urine isolates.

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Despite the known clonal distribution of antibiotic resistance in many bacteria, empiric (pre-culture) antibiotic selection still relies heavily on species-level cumulative antibiograms, resulting in overuse of broad-spectrum agents and excessive antibiotic/pathogen mismatch. Urinary tract infections (UTIs), which account for a large share of antibiotic use, are caused predominantly by Escherichia coli, a highly clonal pathogen. In an observational clinical cohort study of urgent care patients with suspected UTI, we assessed the potential for E.

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Background: The infection and prevalence of extended-spectrum β-lactamases (ESBLs) is a worldwide problem, and the presence of ESBLs varies between countries. In this study, we investigated the occurrence of plasmid-mediated ESBL/AmpC/carbapenemase/aminoglycoside resistance gene expression in Escherichia coli using phenotypic and genotypic techniques.

Methods: A total of 58 E.

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(Group A or GAS) is a hemolytic human pathogen associated with a wide variety of infections ranging from minor skin and throat infections to life-threatening invasive diseases. The cell wall of GAS consists of peptidoglycan sacculus decorated with a carbohydrate comprising a polyrhamnose backbone with immunodominant N-acetylglucosamine side-chains. All GAS genomes contain the operon, which encodes a 35-amino-acid membrane protein SpyB, and a membrane-bound C3-like ADP-ribosyltransferase SpyA.

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Background.  Escherichia coli is a highly clonal pathogen. Extraintestinal isolates belong to a limited number of genetically related groups, which often exhibit characteristic antimicrobial resistance profiles.

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Study of individual hepatitis C (HCV) proteins could help to find a molecular structure and conformation, localization of antigenic and immunogenic determinants, to reveal of protective epitopes. It is necessary for practical medicine - development of diagnostic test-systems, vaccines and therapeutics. Linear and conformation dependent epitopes of HCV proteins was localized in this work and immunogenic properties of phage displayed peptides screened on monoclonal antibodies to HCV proteins have been investigated.

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The accumulation of individual hepatitis C virus (HCV) proteins in the liver cells of patients with acute hepatitis C (AHC) and their association with the course and outcome of the disease were studied. AHC protein expression in the cryostat liver sections from 20 patients with AHC was estimated by immunohistochemical assay using original monoclonal antibodies to 5 HCV proteins (core, NS3, NS4A, NS4B, and NS5A). The results of HCV detection in the patients were compared with their biochemical, clinical, and morphological findings.

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