Related Experiment Video
Updated: May 10, 2026
Measurement of BK-polyomavirus Non-Coding Control Region Driven Transcriptional Activity Via Flow Cytometry
Published on: July 13, 2019
BK polyomavirus genotyping at inter- and intra-patient level in Spain
J Ledesma1, E Bouza, M A González-Nicolás
1Influenza and Respiratory Viruses Laboratory, National Center for Microbiology, ISCIII, Majadahonda, Madrid, Spain.
Abstract:
BK polyomavirus (BKV) is classified into four subtypes based on nucleotide variation of a 287 bp typing region in the VP1 protein. Most studies show that subtype I is predominant in different geographic settings, followed by subtype IV. However, BKV subtypes II and III are detected at low rates. In Spain, the prevalence of each subtype is not well known. The aim of this study was to identify the BKV subtypes from a selection of different types of patients and to determine whether different subtypes could be infecting the same patient. A hundred and twenty nine BKV-positive urine samples were selected to amplify and sequence the typing region. Plasma specimens collected at the same time as the urine samples were also studied in 34 patients. A phylogenetic analysis and a study of substitutions in the VP1 protein were carried out with the sequences obtained. Subtype I was the predominant subtype detected in urine (61.2%) and plasma (38.2%) samples followed by subtype II. The analysis of paired samples showed that the subtype found in urine was different from that found in plasma in 10 patients. Fourteen BKV variants based on substitutions in VP1 were identified. The finding of compartmentalized infections involving different subtypes at different sites in some patients might mean specific and different selective pressure in each tissue. The potential involvement in the viral cycle of the different BKV variants found should be analyzed.
Insights
BK polyomavirus (BKV) subtypes were identified in Spanish patients, with subtype I being most common. Some patients showed different BKV subtypes in urine and plasma, suggesting compartmentalized infections.
Area of Science:
- Virology
- Molecular Biology
- Infectious Diseases
Background:
- BK polyomavirus (BKV) classification relies on VP1 protein variations, with subtypes I and IV frequently detected globally.
- Subtypes II and III of BKV are less commonly reported.
- The prevalence of BKV subtypes in Spain remains largely uncharacterized.
Purpose of the Study:
- To identify BK polyomavirus subtypes in Spanish patients.
- To investigate the co-infection of different BKV subtypes within the same patient.
- To analyze VP1 protein substitutions and their potential implications.
Main Methods:
- Amplification and sequencing of the BKV VP1 typing region from urine and plasma samples.
- Phylogenetic analysis of obtained sequences.
- Identification and characterization of VP1 protein substitutions.
Main Results:
- Subtype I was the predominant BKV subtype in both urine (61.2%) and plasma (38.2%) samples.
- Subtype II was the second most frequently detected subtype.
- In 10 out of 34 patients, different BKV subtypes were found in urine and plasma samples, indicating compartmentalized infections.
- Fourteen distinct BKV variants, defined by VP1 substitutions, were identified.
Conclusions:
- Subtype I is the predominant BK polyomavirus subtype in the studied Spanish cohort.
- Evidence suggests compartmentalized infections with distinct BKV subtypes in different body sites (urine and plasma) within the same patient.
- The identified BKV variants and compartmentalization may indicate tissue-specific selective pressures and warrant further investigation into their role in the viral cycle.
