To estimate the susceptibility to enterovirus infection and the frequency of long-term poliovirus excreters in Tunisian patients with primary immunodeficiencies (PIDs), enteroviruses were assessed in stool specimens of 82 patients with humoral, combined, and other PIDs. Isolated viruses were typed and intratyped by standard molecular techniques, and the whole VP1 region of poliovirus isolates was sequenced. Polioviruses were detected in 6 patients; all isolates were vaccine related. Five patients rapidly stopped excretion; one excreted a poliovirus type 1 isolate for several months, and the isolate accumulated up to 14 mutations in the VP1 region. Nonpolio enteroviruses were identified in 6 patients; 4 of them kept excreting the same strain for more than 6 months. The rate of enterovirus infection was 13.4% of the PID patients and 20.7% of those with an IgG defect; it greatly exceeded the rates generally found in Tunisian supposed-immunocompetent individuals (4.1% during the study period; P ؍ 0.001 and P < 0.0001, respectively). Interestingly, patients with combined immunodeficiencies were at a higher risk for enterovirus infection than those with an exclusively B cell defect. A major histocompatibility complex (MHC) class II antigen expression defect was found in 54% of enterovirus-positive patients and in the unique long-term poliovirus excreter. The study results also suggest that substitutive immunoglobulin therapy may help clearance of a poliovirus infection and that most PID patients have the ability to stop poliovirus excretion within a limited period. However, the high susceptibility of these patients to enterovirus infection reinforces the need for enhanced surveillance of these patients until the use of oral poliovirus vaccine (OPV) is stopped.
Documenting the circulation dynamics of SARS-CoV-2 variants in different regions of the world is crucial for monitoring virus transmission worldwide and contributing to global efforts towards combating the pandemic. Tunisia has experienced several waves of COVID-19 with a significant number of infections and deaths. The present study provides genetic information on the different lineages of SARS-CoV-2 that circulated in Tunisia over 17 months. Lineages were assigned for 1359 samples using whole-genome sequencing, partial S gene sequencing and variant-specific real-time RT-PCR tests. Forty-eight different lineages of SARS-CoV-2 were identified, including variants of concern (VOCs), variants of interest (VOIs) and variants under monitoring (VUMs), particularly Alpha, Beta, Delta, A.27, Zeta and Eta. The first wave, limited to imported and import-related cases, was characterized by a small number of positive samples and lineages. During the second wave, a large number of lineages were detected; the third wave was marked by the predominance of the Alpha VOC, and the fourth wave was characterized by the predominance of the Delta VOC. This study adds new genomic data to the global context of COVID-19, particularly from the North African region, and highlights the importance of the timely molecular characterization of circulating strains.
Echovirus 6 (E6) and echovirus 11 (E11) are common causes of meningitis and other human diseases; they are among the most frequently isolated enteroviruses worldwide. In the present work we have studied genetic variability over the entire VP1 gene of selected isolates representing a wide geographical and temporal range. Fifty new sequences from North Africa were included, together with previously published sequences from different countries. The sequence diversity between strains of the same type was high: 22 and 30 % for E6 and E11, respectively. Phylogenetic analysis revealed five genogroups within each type, the genetic diversity within a genogroup generally being ,20 %. Some genogroups were further subdivided into genotypes, most containing isolates that had circulated over a wide geographical (several countries from different continents) and temporal (up to two decades) range. Several genotypes were also shown to co-circulate in a region during the same period of time. These features differ from other enteroviruses that divide into temporal or geographical clusters. This study reports new sequences from North Africa, updates the molecular epidemiology of E6 and E11, and proposes a new genogroup in each type. INTRODUCTIONHuman enteroviruses (HEVs) are small non-enveloped viruses with a worldwide distribution. Laboratory diagnosis of related infections currently is based on virus detection by isolation in cell culture or by direct PCR amplification from clinical samples. HEV types are identified by seroneutralization or partial sequencing of the VP1 region (Caro et al., 2001;Norder et al., 2001;Oberste et al., 1999a Oberste et al., , b, 2000Palacios et al., 2002). Similar to other RNA viruses, HEVs have a high capacity to evolve genetically. Genotypes are identified based on the genetic variability and phylogenetic relationships among isolates. The circulation of these genotypes throughout the world and over time has been studied to increase our understanding of the dynamics of their transmission, to evaluate their endemicity and to explain the extent of epidemics when they occur. Beyond type identification, sequencing of the VP1 region has also proved to be a reliable method for such molecular epidemiological studies.Echovirus 6 (E6) and echovirus 11 (E11) are among the most commonly isolated HEVs worldwide, and are frequently associated with outbreaks and sporadic cases of aseptic meningitis, as well as with several diseases ranging from mild non-specific illness to encephalitis, paralysis, myocarditis and severe systemic infections in neonates (Abe et al., 2000;Ashwell et al., 1996;Atkinson et al., 1998;Bahri et al., 2005;Belguith et al., 2007a;Boyd et al., 1987;Cabrerizo et al., 2008;Chomel et al., 2003;Druyts-Voets, 1997;El-Sageyer et al., 1998;Joo et al., 2005;Khetsuriani et al., 2006;Mao et al., 2010;Mirand et al., 2008;Miwa & Sawatari, 1994;Somekh et al., 2001;Ventura et al., 2001). However, despite their important impact on human health, studies of the molecular epidemiology of E6 and E11 remain li...
Among Coxsackie B viruses, Coxsckievirus B5 is one of the most predominant serotypes in human, it is frequently associated with cases of neurological diseases, epidemics of meningitis and is a common cause of cardiomyopathy and diabetes. In the present study 27 isolates of Coxsackievirus B5 from North Africa, obtained from cerebrospinal fluid and stool samples of healthy individuals, patients with acute flaccid paralysis or aseptic meningitis were investigated by partial sequencing in the 5' half of the VP1 region and compared to the up-to-date published Coxsackievirus B5 sequences in the same genomic region. Four distinct genomic groups and ten different clusters were individualized. Most of the isolates from Algeria and Tunisia belonged to two clusters. For both, the sequences from North Africa clustered mainly with sequences from European countries, the majority isolated recently during the 2000s. The analysis of the alignment of amino-acids sequences in the VP1 gene revealed four major substitutions in strains from different clusters, we also noticed changes in the BC-loop region; this region is associated with viral antigenicity. This study permit to better identify circulating Coxsackievirus B5 strains throughout the world and their genetic relationship. The protein analysis showed changes that could imply some antigenic significance. J. Med. Virol. 83:1247-1254, 2011. © 2011 Wiley-Liss, Inc.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.