First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR

Abstract Background Nested polymerase chain reaction (PCR) targeting the small subunit ribosomal ribonucleic acid (SSU rRNA, 18S rRNA) region is widely used to differentiate Plasmodium species. We identified a variant of the Plasmodium malariae SSU rRNA gene that suggests nested PCR may fail to dete...

Full description

Saved in:
Bibliographic Details
Main Authors: Maki Goto, Kei Yamamoto, Kanako Komaki-Yasuda, Shigeyuki Kano, Norio Ohmagari
Format: Article
Language:English
Published: BMC 2025-08-01
Series:Tropical Medicine and Health
Subjects:
Online Access:https://doi.org/10.1186/s41182-025-00787-5
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849235616225558528
author Maki Goto
Kei Yamamoto
Kanako Komaki-Yasuda
Shigeyuki Kano
Norio Ohmagari
author_facet Maki Goto
Kei Yamamoto
Kanako Komaki-Yasuda
Shigeyuki Kano
Norio Ohmagari
author_sort Maki Goto
collection DOAJ
description Abstract Background Nested polymerase chain reaction (PCR) targeting the small subunit ribosomal ribonucleic acid (SSU rRNA, 18S rRNA) region is widely used to differentiate Plasmodium species. We identified a variant of the Plasmodium malariae SSU rRNA gene that suggests nested PCR may fail to detect P. malariae strains with unknown mutations. Case presentation A 56-year-old Japanese man developed a fever 2 months after returning from a 2-month stay in Sierra Leone. Quartan malaria was suspected based on blood smear findings, and nested PCR confirmed P. malariae infection. However, the secondary PCR band obtained using P. malariae-specific primers was fainter than the primary PCR band amplified with universal primers—a reversal of the typical pattern. Sequence analysis revealed a four-base deletion in the SSU rRNA gene within the primer-binding site of the species-specific reverse primer used in the secondary PCR, suggesting that mutations in this region may partially impair amplification and hinder species identification. Cytochrome b gene sequencing confirmed 100% identity with P. malariae. Conclusions These findings underscore the need for continued molecular surveillance and sequence-based validation to ensure accurate diagnosis of Plasmodium infections, particularly in regions where genetic variants and zoonotic strains are emerging.
format Article
id doaj-art-66d2ebf86e5d48bea890201b4ce2219b
institution Kabale University
issn 1349-4147
language English
publishDate 2025-08-01
publisher BMC
record_format Article
series Tropical Medicine and Health
spelling doaj-art-66d2ebf86e5d48bea890201b4ce2219b2025-08-20T04:02:44ZengBMCTropical Medicine and Health1349-41472025-08-015311510.1186/s41182-025-00787-5First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCRMaki Goto0Kei Yamamoto1Kanako Komaki-Yasuda2Shigeyuki Kano3Norio Ohmagari4Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan Institute for Health Security (JIHS)Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan Institute for Health Security (JIHS)Department of Tropical Medicine and Malaria, Research Institute of Global Health and Medicine, JIHSDepartment of Tropical Medicine and Malaria, Research Institute of Global Health and Medicine, JIHSDisease Control and Prevention Center, National Center for Global Health and Medicine, Japan Institute for Health Security (JIHS)Abstract Background Nested polymerase chain reaction (PCR) targeting the small subunit ribosomal ribonucleic acid (SSU rRNA, 18S rRNA) region is widely used to differentiate Plasmodium species. We identified a variant of the Plasmodium malariae SSU rRNA gene that suggests nested PCR may fail to detect P. malariae strains with unknown mutations. Case presentation A 56-year-old Japanese man developed a fever 2 months after returning from a 2-month stay in Sierra Leone. Quartan malaria was suspected based on blood smear findings, and nested PCR confirmed P. malariae infection. However, the secondary PCR band obtained using P. malariae-specific primers was fainter than the primary PCR band amplified with universal primers—a reversal of the typical pattern. Sequence analysis revealed a four-base deletion in the SSU rRNA gene within the primer-binding site of the species-specific reverse primer used in the secondary PCR, suggesting that mutations in this region may partially impair amplification and hinder species identification. Cytochrome b gene sequencing confirmed 100% identity with P. malariae. Conclusions These findings underscore the need for continued molecular surveillance and sequence-based validation to ensure accurate diagnosis of Plasmodium infections, particularly in regions where genetic variants and zoonotic strains are emerging.https://doi.org/10.1186/s41182-025-00787-5Plasmodium malariaeNested PCRSSUrRNA18S rRNASpecies-specific primerSequence analysis
spellingShingle Maki Goto
Kei Yamamoto
Kanako Komaki-Yasuda
Shigeyuki Kano
Norio Ohmagari
First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
Tropical Medicine and Health
Plasmodium malariae
Nested PCR
SSUrRNA
18S rRNA
Species-specific primer
Sequence analysis
title First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
title_full First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
title_fullStr First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
title_full_unstemmed First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
title_short First report of a Plasmodium malariae SSU rRNA gene variant in Africa associated with reduced amplification by nested PCR
title_sort first report of a plasmodium malariae ssu rrna gene variant in africa associated with reduced amplification by nested pcr
topic Plasmodium malariae
Nested PCR
SSUrRNA
18S rRNA
Species-specific primer
Sequence analysis
url https://doi.org/10.1186/s41182-025-00787-5
work_keys_str_mv AT makigoto firstreportofaplasmodiummalariaessurrnagenevariantinafricaassociatedwithreducedamplificationbynestedpcr
AT keiyamamoto firstreportofaplasmodiummalariaessurrnagenevariantinafricaassociatedwithreducedamplificationbynestedpcr
AT kanakokomakiyasuda firstreportofaplasmodiummalariaessurrnagenevariantinafricaassociatedwithreducedamplificationbynestedpcr
AT shigeyukikano firstreportofaplasmodiummalariaessurrnagenevariantinafricaassociatedwithreducedamplificationbynestedpcr
AT norioohmagari firstreportofaplasmodiummalariaessurrnagenevariantinafricaassociatedwithreducedamplificationbynestedpcr