Rice yellow mottle virus is a suitable amplicon vector for an efficient production of an anti-leishmianiasis vaccine in Nicotiana benthamiana leaves.

BACKGROUND: Since the 2000's, plants have been used as bioreactors for the transient production of molecules of interest such as vaccines. To improve protein yield, "amplicon" vectors based on plant viruses are used. These viral constructs, engineered to carry the gene of interest replicate strongly once introduced into the plant cell, allowing significant accumulation of the protein. Here, we evaluated the suitability of the monocot-infecting RNA virus Rice yellow mottle virus (RYMV) as an amplicon vector. The promastigote surface antigen (PSA) of the protozoan Leishmania was considered as a protein of interest due to its vaccine properties against canine leishmaniasis. RESULTS: Since P1 (ORF1) and CP (ORF3) proteins are not strictly necessary for viral replication, ORF1 was deleted and the PSA gene was substituted to ORF3 in the RYMV-based vector. We evaluated its expression in the best described plant bioreactor system, Nicotiana benthamiana which, unlike rice, allows transient transformation by Agrobacterium. Despite not being its natural host, we demonstrated a low level of RYMV-based vector replication in N. benthamiana leaves. Under optimized ratio, we showed that the P19 silencing suppressor in combination with the missing viral CP ORF significantly enhanced RYMV amplicon replication in N. benthamiana. Under these optimized CP/P19 conditions, we showed that the RYMV amplicon replicated autonomously in the infiltrated N. benthamiana cells, but was unable to move out of the infiltrated zones. Finally, we showed that when the RYMV amplicon was expressed under the optimized conditions we set up, it allowed enhanced PSA protein accumulation in N. benthamiana compared to the PSA coding sequence driven by the 35S promoter without amplicon background. CONCLUSION: This work demonstrates that a non-dicot-infecting virus can be used as an amplicon vector for the efficient production of proteins of interest such as PSA in N. benthamiana leaves.

Molecular Epidemiology of Rotavirus in Children under Five in Africa (2006-2016): A Systematic Review.

Group A human rotaviruses (RVA) are the most common causes of severe viral gastroenteritis in infants and young children worldwide. The available vaccines, while effective in Europe and North America have shown a reduced efficacy in Africa. One issue raised is the genetic variability of RVA. The objective of this study was to perform a literature review of molecular epidemiology to determine the prevalence of RVA genotypes circulating in Africa so as to establish a mapping of reliable data on these various genotypes. The search for articles was done from the National Institutes of Health (PUBMED) using three set of keywords. Articles were selected with inclusion criteria such as the date of publication, the age of the children, the sample size and the diagnostic techniques (standardized laboratory techniques). The data were imported into STATA SE version 11 software. Specific prevalence was estimated with Confidence Intervals (CI) of 95%. A total of 326 published studies were initially retrieved, out of which 27 studies were finally selected for the systematic review. The selected studies cover 20 African countries. The most encountered genotypes in Africa during this period were G1 (32.72%), followed by G2 (17.17%), G3 (9.88%), G9 (8.61%) and G12 (7.56%) among the G-types. The most common P-types were P[8] (48.71%) followed by P[6] (22.60%) and P[4] (11.58%) and the G1P[8] combination (22.64%) was the most encountered followed by G2P[4] (8.29%), G9P[8] (6.95%) and G2P[6] (5.00%). North Africa presented the highest prevalence of the P[8] genotype (65.70%). This review provides a comprehensive view of the current circulating rotavirus strains in Africa, which can be important in light of the new rotavirus vaccinations. Indeed, in Africa, the pursuit of national and continental studies for epidemiological surveillance of circulating rotavirus strains is vital for the promotion of future successful vaccines.

Oncogenic Human Papillomavirus Infection and Genotype Characterization among Women in Orodara, Western Burkina Faso.

BACKGROUND AND OBJECTIVE: Cervical cancer usually occurs several years after persistent infection with oncogenic or high-risk human papillomavirus. The objective of this study was to determine carriage of 14 genotypes of high-risk human papillomavirus among women at Orodara and then characterize the genotypes found in these women. MATERIALS AND METHODS: From June to July 2015, 120 women from the general population were recruited in the health district of Orodara. They voluntarily agreed to participate in the study. Endocervical samples were taken from these women prior to screening for precancerous lesions by visual inspection with acetic acid and lugol's iodine. Identification of high-risk human papillomavirus genotype was done using real-time PCR. RESULTS: High-risk human papillomavirus prevalence was 38.3% and the most common genotypes were HPV 52 (25.4%), HPV 33 (20.6%) and HPV 59 (11.1%). The HPV 66 was also identified with a prevalence of 9.5%. CONCLUSION: The HPV 16 and HPV 18 which are frequently associated with cancer worldwide were not found among the most frequent oncogenic HPV in women in Orodara.

[Epidemiology and characterization of high-risk genotypes of human Papillomavirus in a population of sexually active adolescents in Ouagadougou]. / Épidémiologie et caractérisation des génotypes à haut risque de Papillomavirus humain dans une population d'adolescentes sexuellement actives à Ouagadougou.

OBJECTIVE: This cross-sectional study was to determine the prevalence and characterization of high-risk HPV genotypes circulating among adolescents in Ouagadougou. METHODS: From September to December 2013, 200 adolescents recruited from a youth counseling center have voluntarily accepted a swab of the endocervical canal. The identification of the genotypes of the human Papillomavirus (HPV) was performed by real-time polymerase chain reaction technique. RESULTS: The mean age of adolescents was 18.7±0.7 years and 83/200 adolescents were positive for at least one high-risk genotype HPV a prevalence of 41.5%. Twelve genotypes corresponding to 136 infections were characterized: HPV 52 (22.8%), HPV 59 (14.0%), HPV 39 (13.2%), HPV 35 (10.3%), HPV 51 (10.3%), HPV 56 (8.8%), HPV 16 (5.2%), HPV 18 (5.2%), HPV 58 (4.4%), HPV 31 (3.6%), HPV 45 (1.5%), HPV 33 (0.7%). Multiple infections (2-5 virus) statistically associated with age (p=0.0318) was detected in 42.2% of infected females. If the number of sexual partners was statistically associated with the porting of HPV (OR=2.18; 95% CI=1.17 to 4.09), early sexual intercourse and the recent change of sexual partner were not (p>0,05) CONCLUSION: The prevalence of carriage of HPV in this study is high, as described in young people at the start of sexual activity. Identified genotypes are different from those targeted by prophylactic vaccines currently available. A larger study to map genotypes of high-risk HPV circulating in West Africa is necessary for a suitable vaccine.

Prevalence of HBV and HCV markers among patients attending the Saint Camille Medical Centre in Ouagadougou.

HCV and HBV cause annually, 2000 deaths from liver cancer in Burkina Faso. In this country, serological screening of hepatitis viruses B and C is only systematic among blood donors. The aims of this study were; (1) to investigate the reasons for the prescription of the screening for hepatitis B and C; (2) to determine HCV and HBV prevalence among 462 patients attending the Saint Camille Centre and (3) to identify patients with acute hepatitis or with chronic hepatitis for better monitoring. From February to May 2012, 462 patients attending the laboratory of the Saint Camille Medical Centre with viral hepatitis suspicion were screened. The hepatitis B and C serological markers were detected through Enzyme Immuno Assay (EIA) technique using commercial reagent kits. The clinical symptoms were also recorded for each patient. The results revealed that, the main clinical symptoms that prompted physicians to request HBV and HCV screenings were: asthenia (39.4%), anorexia (21.2%), abdominal pains (19.0%), nausea (10.4%), others (10.0%). The prevalence of HbsAg was 29.4% among the screened people. Patients with acute hepatitis B, active chronic hepatitis B and non-active chronic hepatitis B represented 11.2, 2.2 and 16.0%, respectively. The acquisition of immunity against HBV after vaccination was attempted for 11.7% people. HCV prevalence was 3.9% and its coinfection with HBV was 2.2%. This study showed a high prevalence for hepatitis B and C among patients attending Saint Camille Medical Centre. Without hygiene education and HBV/HCV prevention, viral hepatitis infection will become a serious public health problem in Burkina Faso.

[Epidemiology, characterization of genotypes of human papillomavirus in a population of women in Ouagadougou]. / Épidémiologie et caractérisation des génotypes de papillomavirus humain dans une population de femmes à Ouagadougou.

OBJECTIVES: This work was carried out in order to determine the prevalence of different HPV genotypes in a population of women attending gynecological consultation. MATERIAL AND METHODS: From May to June 2010, cervical samples were obtained from 300 women attending gynecological consultation in two health centers in Ouagadougou. The strains of HPV genotyping was done using the technique of polymerase chain reaction (PCR) followed by reverse hybridization on nitrocellulose strips. RESULTS: Among the 73 women(24.3%) infected with HPV, only 27.4% (20/73) of them were infected with a HPV low risk (BR), the 72.6% (53/73). Other women were infected with at least one high risk HPV (HR). By combining the HPV genotypes found without taking into account the number of infected women, we found a total of 84 HPV among whom we have high-risk HPV : HPV-50'S(26/84 or 31.0%), HPV-18 (12/84 or 14.3%), HPV-16 (9/84 or 10.7%), HPV-30'S (5/84 or 5.9%), HPV-HR (5/84 or 5.9%) and HPV-45 (3/84 or 3.6%) and low-risk HPV: HPV-6 (15/84 or 17.9%) and HPV-BR (9/84 or 10.7%). We have found no HPV-11. DISCUSSION AND CONCLUSION: The prevalence of HPV found in our series is comparable to that found in the world. To complete this study, it would be necessary to investigate the prevalence of HPV found in cervical lesions in Burkina Faso.

Prevalence and genotype characterization of human papillomaviruses among HIV-seropositive in Ouagadougou, Burkina Faso.

BACKGROUND: Approximately, 15-20 of 40 HPVs that infect the female genital tract confer a high-risk of invasive cancer, thus HPVs account for 95% of cervix cancers. The objectives of this study were to: (i) estimate the prevalence of HPV infection in women infected with HIV in Ouagadougou, (ii) identify potential carcinogenic HPV strains and (iii) determine whether existing HPV vaccines match the isolated strains. METHODS: From May 2009 to April 2010, 250 HIV-infected women were included in this study. Each woman was screened for the presence of HPV and for HPV genotype using PCR/hybridization technique. RESULTS: Of the 250 HIV-infected women, 59.6% were infected with at least one type of HPV. High-risk HPVs were identified with the following prevalence: HPV-18 (25.0%); HPV-50'S (25.5%); HPV-30'S (20.8%); HPV-16 (4.7%); HPV-45 (3.7%). Low-risk HPVs were represented by HPV-6 (5.7%) and HPV-11 (0.9%). CONCLUSION: The issue of the study showed that the existing vaccines: Gardasil and Cervarix may be used in the country although they match only HPV-16, HPV-18, HPV-6 and HPV-11. Further investigations should be continued for the establishment of vaccine that matches all genotypes circulating in the country.