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Papers by OUAFAA FASSI FIHRI

Microbiology resource announcements, May 10, 2024

Tropical medicine and infectious disease, Jun 26, 2024

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Virus Evolution

Our knowledge of the diversity of eukaryotic viruses has recently undergone a massive expansion. ... more Our knowledge of the diversity of eukaryotic viruses has recently undergone a massive expansion. This diversity could influence host physiology through yet unknown phenomena of potential interest to the fields of health and food production. However, the assembly processes of this diversity remain elusive in the eukaryotic viromes of terrestrial animals. This situation hinders hypothesis-driven tests of virome influence on host physiology. Here, we compare taxonomic diversity between different spatial scales in the eukaryotic virome of the mosquito Culex pipiens. This mosquito is a vector of human pathogens worldwide. The experimental design involved sampling in five countries in Africa and Europe around the Mediterranean Sea and large mosquito numbers to ensure a thorough exploration of virus diversity. A group of viruses was found in all countries. This core group represented a relatively large and diverse fraction of the virome. However, certain core viruses were not shared by all...

Revue Scientifique Et Technique De L Office International Des Epizooties, Dec 1, 1999

Résumé Un protocole de vaccination de trois chevaux, par cinq injections répétées du vaccin à vir... more Résumé Un protocole de vaccination de trois chevaux, par cinq injections répétées du vaccin à virus équipestique inactivé sérotype-4, a été entrepris afin de déterminer un éventuel seuil d'apparition des anticorps contre la protéine non structurale NS3. L'épreuve immuno-enzymatique (ELISA) indirecte utilisant la protéine recombinante NS3 comme antigène, a permis de détecter une réponse vis-à-vis de NS3 dès la deuxième injection pour le premier cheval et après quatre injections pour le deuxième cheval. Aucune réponse vis-à-vis de NS3 n'a été détectée pour le troisième cheval. Ce résultat montre que le vaccin inactivé n'est pas suffisamment purifié pour éliminer la protéine non structurale NS3. Il ne pourrait permettre, en l'occurrence, de différencier les chevaux vaccinés des chevaux infectés en utilisant la protéine NS3 comme marqueur.

Veterinary World, Aug 7, 2021

Background and Aim: Mannheimia haemolytica (Mha) is a common agent of pneumonia in ruminants glob... more Background and Aim: Mannheimia haemolytica (Mha) is a common agent of pneumonia in ruminants globally, causing economic losses by morbidity, mortality, and treatment costs. Infection by Mha is often associated with or promoted by respiratory viral pathogens and environmental conditions. Infections due to Mha have rarely been described in small ruminants. This study reports the biological and molecular characteristics of a new Moroccan Mha isolate from small ruminants presenting typical respiratory symptoms. We also studied the cultural parameters, growth kinetics, and Lkt excretion of the isolate and its pathogenicity on laboratory animals and small ruminants. Materials and Methods: Suspected pasteurellosis cases in sheep and goat flocks in Morocco were investigated. A local strain of Mha was isolated and identified using biochemical and molecular methods. Polymerase chain reaction-targeting specific genes were used for serotyping and phylogenetic analyses; further, leukotoxin production, cytotoxicity, and pathogenicity of the isolate in mice, goats, and sheep were investigated. Results: Phylogeny analysis revealed 98.76% sequence identity with the USA isolate of 2013; the strain growth with a cycle of 9-10 h with leukotoxin secretion was detected by NETosis and quantified by cytotoxicity and mortality of mice. Goat and sheep infections cause hyperthermia, with characteristic postmortem lesions in the trachea and lung. Conclusion: A local isolate of Mha from sheep that died of pneumonia was characterized for the 1 st time in North Africa using biological and molecular methods. Although growth on appropriate culture media is accompanied by intense leukotoxin secretion, experimental infections of sheep and goats cause hyperthermia and typical lesions of pneumonia.

Archives of Virology, Oct 26, 2018

Very virulent infectious bursal disease virus (vvIBDV), the cause of significant economic losses ... more Very virulent infectious bursal disease virus (vvIBDV), the cause of significant economic losses in many poultry-producing areas, has been present in Morocco since 1991. In spite of the introduction of vaccination, disease outbreaks are frequently observed. To ascertain if vaccines failure may be due to the emergence of new strains, the aim of this study was to perform for the first time the molecular characterization of vvIBDV strains circulating in Morocco by focusing on the hypervariable region (HVR) of the VP2 protein, which is frequently used for molecular epidemiology and phylogenetic studies. Field samples of haemorrhagic bursae of Fabricius were collected for molecular characterization in different parts of the country during 2016-2017 from 48 chicken flocks showing symptoms of disease. In a phylogenetic tree, nucleotide sequences containing the VP2 HVR of 13 samples that were positive for vvIBDV formed a common branch with those of vvIBDV references strains published in GenBank, but they clearly grouped into a distinct subcluster. An alignment of the deduced amino acid sequences, in addition to confirming the presence of the “signature” typical of the vvIBDV HVR, also revealed the presence of substitutions in hydrophilic loops that are known to be involved in the elicitation of neutralizing antibodies. One of these substitutions is unique to the Moroccan isolates. These results represent the first molecular characterization of vvIBDV isolates in Morocco and may indicate that one of the causes of vaccine ineffectiveness is antigenic drift.

Scientific Reports, Nov 14, 2022

Bluetongue is an arthropod-borne viral disease transmitted by Culicoides biting midges, affecting... more Bluetongue is an arthropod-borne viral disease transmitted by Culicoides biting midges, affecting domestic and wild ruminants. The current study aims to assess the seroprevalence of the bluetongue virus (BTV) and confirm its active circulation among sheep and goats populations in Morocco, as well as study the risk factors associated with BTV infection. To this end, a total of 1651 samples were randomly collected from 1376 sheep and 275 goats in eight (out of 12) regions of the country between March 2018 and July 2021.These samples were primarily tested using competitive ELISA (c-ELISA). Subsequently, 65% of c-ELISA positives (n = 452) were analyzed by real-time reverse transcriptionpolymerase chain reaction (RT-qPCR). The results revealed an overall BTV seroprevalence in small ruminants in Morocco of 41.7%, including 42.6% in sheep and 37.5% in goats. The RT-qPCR results showed that the overall BTV viropositivity rate was 46.7%, including 48.1% in sheep and 41.8% in goats. These viro-serological rates varied significantly by age, sex, and breed of the tested animals, husbandry method, season, and geographic origin. This indicates that these parameters constitute risk factors for BTV transmission routes in Morocco. The findings also indicate that goats play a role as reservoirs in maintaining the BTV in Morocco. It appears from this study that bluetongue is endemic in Morocco. The environmental and climate conditions as well as the husbandry methods adopted in the country are particularly favorable for the virus transmission throughout the country. Bluetongue is a viral disease of domestic and wild ruminants caused by the bluetongue virus (BTV) and transmitted primarily by Culicoides biting midges 1. Bluetongue is a disease currently notifiable to the World Organization for Animal Health (WOAH). The clinical incidence varies according to the animal species and BTV serotype 2. The repercussions are more severe in the sheep sector, with significant economic losses in flocks attributable to abortions, reduced production parameters and fertility rates, diagnostic and control measure costs, and trade restrictions 3. Bluetongue virus is a small non-enveloped virus of the orbivirus genus within the Reoviridae family 4 , with ten double-stranded RNA linear segments encoding seven structural (VP1-VP7) and five non-structural proteins (NS1, NS2, NS3/NS3A, NS4, NS5) 5. To date, 27 serotypes were described worldwide, including BTV-25 detected in Switzerland in 2007 6 , BTV-26 identified in Kuwait in 2010 7 , and BTV-27 isolated from goats in Corsica in 2014 8. In addition, novel putative serotypes have been recently identified. BTV-28 (grouping BTV-28/1537/14 with SPvvv/03) and BTV-29 (SPvvv/02) isolated from sheeppox vaccine, BTV-30 which combine BTV-XJ1407 (China) and BTV-MNG2/2016 (Mongolia), BTV-31 (V196/XJ/2014) isolated in China, BTV-32 (BTV-X ITL2015) in Italy, BTV-33 (BTV-MNG3/2016) in Mongolia, BTV-34 (BTV-Y TUN2017) in Tunisia, BTV-35 (BTV-MNG1/2018) in Mongolia, and BTV-36 (BTV-36-CH2019) in Switzerland. Novel BTV strains were also detected in alpacas in South Africa but have not been genotyped 9-16. Laboratory diagnosis of the disease is based on serological and molecular techniques for serogrouping and serotyping of BTV 17. The VP2, the most variable structural protein that triggers neutralizing antibodies production, determines BTV serotypes 18. The VP7 protein is relatively conserved and serves as the main immunogenic serogroup-reactive antigen of BTV 19. The detection of Anti-VP7 antibodies is the primary target of the BTV ELISA serological assays 1. Bluetongue virus have been identified in many tropical, subtropical, and temperate areas between 40° North and 35° South latitudes 20 , where the climatic factors are favorable to the activity of Culicoides spp. In Morocco, bluetongue was first reported in 1956 in the southern zone of Larache and west of Arbaoua

Veterinary World, Apr 1, 2023

Background and Aim: Footrot is a contagious disease of ruminants leading to severe economic losse... more Background and Aim: Footrot is a contagious disease of ruminants leading to severe economic losses. This study aimed to estimate the prevalence, virulence, and serogroups of Dichelobacter nodosus and the prevalence of Fusobacterium necrophorum in footrot lesions of sheep and cattle. Materials and Methods: A total of 106 pathogenic lesion samples were taken from 74 sheep and 32 cattle exhibiting typical footrot lesions and were analyzed for the presence of D. nodosus and F. necrophorum by real-time polymerase chain reaction (PCR). Both virulence and serogroup were estimated for D. nodosus positive samples. Results: Among the 106 samples, 89 were positive by PCR for F. necrophorum, D. nodosus, or both. Dichelobacter nodosus was detected at a rate of 78.3% versus 28.3% for F. necrophorum. Virulent D. nodosus strains were detected in 67.5% of positive samples, with a higher rate in sheep (73.4%) than in cattle (47.4%). Benign D. nodosus strains were detected in 57.8% of samples, with a lower prevalence rate in sheep (50%) than in cattle (84.2%). The positive samples of D. nodosus revealed the presence of three dominant serogroups (D, H, I) and three minor serogroups (G, C, A) by serogroup-specific multiplex PCR. Conclusion: The findings provided information on the prevalence of D. nodosus and F. necrophorum strains in footrot lesions of sheep and cattle in some regions of Morocco, which will be useful for developing an effective autovaccine for the prevention of this disease in cattle and sheep in these regions.

Brazilian Journal of Microbiology

bioRxiv (Cold Spring Harbor Laboratory), Nov 25, 2022

Our knowledge on the diversity of eukaryotic viruses has recently undergone a massive expansion. ... more Our knowledge on the diversity of eukaryotic viruses has recently undergone a massive expansion. This diversity could influence host physiology through yet unknown phenomena of potential interest to the fields of health and food production. However, the assembly processes in eukaryotic viromes of terrestrial animals remain elusive. This situation hinders hypothesis-driven tests of virome influence on host physiology. Here, we explore virome assembly at different spatial scales in the eukaryotic virome of the mosquito Culex pipiens. This mosquito is a vector of human pathogens worldwide. Several new aspects of virome assembly were unveiled through a sampling involving five countries in Africa and Europe and large sample sizes. A group of viruses was conserved in C. pipiens populations in all countries. This core group represented a relatively large and diverse fraction of the virome. However, core viruses were not shared by all host individuals in a given country, and their infection rates fluctuated between countries and years. Moreover, the distribution of co-infections in individual mosquitoes suggested random co-occurrence of certain core viruses. We also observed differences in the virome depending on geography, with viromes tending to cluster depending on the continent. Thus, our results unveil that taxon conservation in a eukaryotic virome changes with spatial scale. Thus, predictions on virome assembly seem possible at a large geographical scale in C. pipiens. IMPORTANCE The study of the eukaryotic virome of mosquitoes is an emerging research field. Beyond its fundamental interest, this field could lead to the development of control tools against the transmission of mosquito-borne human pathogens. However, we yet know little on the assembly patterns in the eukaryotic viromes of mosquitoes, as well as of terrestrial animals in general. This situation hampers the design of hypothesis-driven studies on the influence of the virome on pathogen transmission. Here, we have analyzed virome assembly in the mosquito vector Culex pipiens within and between countries in Africa and Europe. Our results show that integrating contrasted spatial scales allows to identify deterministic patterns in virome assembly. Such patterns can guide future studies of virome influence on mosquito physiology. .

Journal of equine veterinary science, 2021

In order to evaluate the effect of three different primary vaccination intervals on EI vaccine re... more In order to evaluate the effect of three different primary vaccination intervals on EI vaccine response, 21 unvaccinated thoroughbred foals were randomly divided into three groups of 7 and vaccinated with three different intervals of primary immunization (i.e., with 1, 2 or 3 months intervals between V1 and V2, respectively). The antibody response was measured for up to 1 year after the third immunization V3 (administered 6 months after V2) by single radial hemolysis (SRH) assay. All weanlings had seroconverted and exceeded the clinical protection threshold 2 weeks after V2 and 1 month after V3 until the end of the study. Significant differences were measured at the peak of immunity after V2 and for the duration of the immunity gap between V2 and V3. The group with one month primary vaccination interval had a lower immunity peak after V2 (158.05 ± 6.63 mm2) and a wider immunity gap between V2 and V3 (18 weeks) when compared with other groups (i.e., 174.72 ± 6.86 mm2 and 16 weeks for...

The aim of the current study is to evaluate the pathogenicity of recent infectious bursal disease... more The aim of the current study is to evaluate the pathogenicity of recent infectious bursal disease virus (IBDV) (1/chicken/Morocco/IB19/2017) genetically characterized as vvIBDV belonging to genogroup 3.Two chicken lines, broiler and speciﬁc-pathogen-free (SPF) chickens, were inoculated by occulonasal route with 0.2 ml of the 105EID50 /ml of viral solution of IB19 vvIBDV strain at 29 days of age. The experimental monitoring was carried out during 10 days post challenge (dpc). The clinical signs stared on day 2 pc with maximum severity observed between 3 and 6 dpc. The total mortality rate reached 10% in broilers (group G1) and 93% in SPF (G3). The macroscopic lesions in broilers G1 was a marked hypertrophy of the bursa of Fabricius (BF) with slight haemorrhage observed between 2 to 4 dpc, followed by very pronounced atrophy observed on the 5 dpc. The post-mortem examinations of dead SPF birds (G3) revealed on 3 dpc very haemorrhagic BF with black cherry appearance in 80 % of dead bir...

GMPC Thesis and Opinions Platform, 2021

Co-infection with low pathogenic avian influenza virus (LPAIV) H9N2 and Newcastle disease virus (... more Co-infection with low pathogenic avian influenza virus (LPAIV) H9N2 and Newcastle disease virus (NDV) has become a worrying concern for the poultry industry. The problem arises when the hidden virus influences the replication of another suspected virus. Subsequently, misdiagnosis of the actual cause may be ended up as a source of contamination for the other healthy flocks by the spread of the covered-up virus. In this preliminary study, we determined the potential impact of concurrent infection with H9N2 and avirulent NDV (Lasota) on the virus replication in Specific Pathogen-Free embryonated chicken egg (SPF-ECE) model. Assessment of the potential interference phenomena was carried out based on embryonic lesions, mortalities, and virus replication using real-time PCR. Our results showed that H9N2 interferes with LaSota growth, regardless of which infection occurred first. Our obtained preliminary results are a call for scientists to study the interference between LPAIV H9N2 and NDV...

Revue Marocaine Des Sciences Agronomiques Et Veterinaires, Jul 3, 2015

Le virus de bronchite infectieuse aviaire fait partie des virus aviaires majeurs rencontrés chez ... more Le virus de bronchite infectieuse aviaire fait partie des virus aviaires majeurs rencontrés chez les poulets depuis les débuts de l'élevage industriel. On retrouve la maladie de bronchite infectieuse dans la plupart des pays producteurs de volailles au niveau mondial. Malgré l'utilisation de vaccins qui contribuent au contrôle des signes cliniques, l'émergence de nouveaux virus sauvages variants conforte le fait que la bronchite infectieuse est une cible mouvante difficile à maîtriser. Le présent article est une mise à jour des connaissances sur la distribution épidémiologique et moléculaire des variants de l'IBV dans les différents pays du monde.

BMC Research Notes, 2016

Background: A rapid, sensitive, and specific molecular method for the diagnosis of infectious bro... more Background: A rapid, sensitive, and specific molecular method for the diagnosis of infectious bronchitis virus (IBV) infection is important in curbing infectious bronchitis outbreaks in Morocco and other countries. Methods: In this study, an easy-to-perform SYBR green I real-time reverse transcriptase polymerase chain reaction (RT-PCR) targeting the nucleocapsid gene of IBV was developed and compared with conventional agarose gel-based RT-PCR for the detection of IBV infection. Results: We found that the SYBR green I real-time RT-PCR was at least 10 times more sensitive than the agarose gel electrophoresis detection method. The assay exhibited high specificity for IBV infection. All negative controls, such as Newcastle disease virus, infectious bursal disease virus, and avian influenza virus, were not detected. Conclusion: The SYBR green I real-time RT-PCR test described herein can be used to rapidly distinguish IBV from other respiratory pathogens, which is important for diagnosis and control of infectious bronchitis outbreaks in Morocco. The test is a valuable and useful method as a routine assay for diagnosis of clinical IBV infection in commercial chickens.

Acta Tropica, 2015

We evaluate an integrated health messaging approach for five zoonoses in Morocco.  Access and re... more We evaluate an integrated health messaging approach for five zoonoses in Morocco.  Access and receptivity at schools was greater than at community level.  Information overload occurred when disease transmission pathways did not overlap.  Piggy-backing on high-priority diseases generates synergy.  Incorporating zoonoses into the school curriculum is an appealing approach.

African Horse Sickness, 1998

A Western immunoblotting procedure has been developed for the detection of African horse sickness... more A Western immunoblotting procedure has been developed for the detection of African horse sickness virus (AHSV) protein-specific antibody responses. This assay readily identifies antibodies specific for at least 4 distinct, AHSV proteins, including VP5, NS1, NS2 and NS3/NS3a. By using the AHSV non-structural proteins as 'markers', the Western blotting procedure could be employed to provide a reliable means of discriminating between animals vaccinated with a purified, inactivated AHSV vaccine and those either naturally infected or vaccinated with a live, attenuated AHSV vaccine.