The virus, designated MVI/rabat.mar/29.24comes from a nasopharyngeal sample taken on March 23, 2024 on a 32 -year -old patient hospitalized at the Mohammed V military instruction hospital, with febrile cough accompanied by characteristic rashes, but without severe complications
A team of researchers based in Rabat has fully analyzed the genetic heritage coding an isolated measles virus on a Moroccan patient, offering a scientific milestone of importance in the molecular hunt for this viral disease which experienced a worrying boost in several Moroccan regions, according to a study revealed Monday, May 5.
This virus, named MVI/rabat.mar/29.24was taken on March 23, 2024 on a 32 -year -old woman hospitalized at the Military Instruction Hospital Mohammed V, with a fever, a persistent cough and a typical maculopapule eruption, notable clinical gravity. The national Health alert, issued this same month by the Ministry of Health and Social Protection, pointed out a generalized resurgence of cases.
A complete genetic analysis conducted in Rabat
The pathogen in question belongs to the genre Morbillivirus and to the paramyxoviridae family. It is a virus with a single -year -old RNA of negative polarity, encapsidated, whose genomic structure – 15,894 nucleotides – allows the expression of six structural proteins (N, P, M, F, H, L) and two non -structural proteins (V and C), in accordance with established reference models.
Viral isolation was carried out from infected vero cells. RNA extraction was carried out with the Nucleospin RNA Virus kit (Macherey-inguel, Germany), and its quantification by Nanodrophotometry Nanodrop (Thermo Fisher Scientific, United States). Complementary DNA feedback has been conducted using the RTVA RT (Thermo Fisher Scientific) kit, using 200 NG of initial RNA and random hexamal primers.
-The fragments covering the entire genome were amplified by PCR with a set of published and personalized primers, designed from genetic references MV NC_001498.1 and MN630023.1. Twenty-one distinct amplicons have been sequenced in both directions, 42 individual readings, on a platform Applied Biosystems. The assembly of the sequences was carried out according to the standard settings of the Unipro Ugene software, version 50.5.
A manifest genetic kinship with a strain identified in the United States
The phylogenetic tree generated, based on the nearest neighbors method (neighbor-joining) and enriched with 51 reference genomes from different regions of the globe, attests that the Moroccan strain is the case of genotype B3, according to the classification in force of the World Health Organization (WHO). The robustness of the groupings was validated by a bootstrap test at 500 replicates. The evolutionary distances between the sequences were calculated by the maximum composite composite method.
The strain MVI/rabat.mar/29.24 presents a genetic similarity rate of 99.50 % with the American strain MVs/Virginia.USA/40.21/3[B3]. This proximity suggests an intercontinental movement of the virus, probably facilitated by human flows, although the precise routes remain to be elucidated.
“The complete cartography of the viral genome provides precious benchmarks to identify the transmission foci and guide health interventions in a targeted manner,” explains a researcher involved in the study.
This work, carried out thanks to the support of the Mohammed VI Foundation for Sciences and Health, reinforces the efforts undertaken in Morocco to deepen the knowledge of circulating pathogens and affirm national expertise in molecular virology.
