Diagnostic moléculaire du complexe Mycobacterium tuberculosis résistant à l’isoniazide et à la rifampicine au Burkina Faso

Introduction: cette étude a eu pour objectifs de diagnostiquer la tuberculose pulmonaire par l'examen microscopique et par la PCR des crachats et de déterminer les bases moléculaires de la résistance à la rifampicine et à l'isoniazide. Méthodes: le diagnostic du Complexe Mycobacterium Tuberculosis (CMTB) a été effectué par microscopie après coloration au Ziehl Nielsen et par PCR en temps réel en utilisant le kit d'identification du complexe MTB (Sacace Biotechnologie, Italie). Les résistances à la Rifampicine et à l'Isoniazide ont été étudiées par la technique de la PCR en utilisant le kit MTB résistance 8 (Sacace, Biotechnologie). Résultats: sur les 59 patients diagnostiqués pour la tuberculose pulmonaire, 59,3% étaient positifs en microscopie optique et 44,1% étaient positifs par PCR en Temps réel. Les résistances à la rifampicine (rpoB) et à l'isoniazide (katG et inhA) ont été observées chez 9 patients. La résistance à la rifampicine était due aux mutations (Asp516Val, Ser531Trp, Leu533Pro) et celle à l'isoniazide par les substitutions Ser315Thr du gène katG et C209T du gène inhA. Les multi résistances à la rifampicine et à l'isoniazide ont été observées dans 55,5% des échantillons et concernaient les associations : ropBAsp513Val + inhAC209T et rpoBLeu533Pro + katGSer315Thr. Conclusion: la PCR en temps réel qui permet l'identification des allèles mutants rpoB, katG et inhA de M. tuberculosis est un outil de diagnostic épidémiologique de grande importance car elle permet de déterminer le niveau de résistance à la rifampicine et à l'isoniazide.Keywords: Mycobacterium tuberculosis, résistance, rifampicine, isoniazid

Molecular diagnosis of COVID-19 in Burkina Faso: successful challenge

COVID-19 has worsened the health situation in Burkina Faso. In fact, the country has known a peak of the second wave, which began in November, and ended around January 2021. Biological diagnosis has played a key role in the management of COVID-19. The aim of this review paper is to address the practical aspects that laboratories have faced in order to meet the challenge of SARS-CoV-2 diagnosis in Burkina Faso. According to international requirements, Burkina Faso has used real-time Reverse Transcription Polymerase Chain Reaction (rRT-PCR) as the “gold standard” for the diagnosis of COVID-19. From March 9, 2020 to July 31, 2021, in Burkina Faso, laboratories involved in COVID-19 diagnosis analyzed 226,189 samples by molecular tests and 2, 352 samples by rapid antigenic tests, whose peak was in January 2021 with 35,984 samples analyzed. The daily average rate of samples analysis was 456.02 tests. The majority of the individuals requesting COVID-19 tests were travelers (62.00%), followed by contact cases (18.42%), suspected cases (7.95%), voluntary screening (7.57%), and 4.06% of other applicants consisting of health care personnel and at-risk patients. In terms of prevention, vaccines are being administered to the general population. However, some efforts must be made to provide automated sample analysis equipment and complete sequencing of SARS-CoV-2 remains among the challenges

Screening of BRCA1 (c.5177_5180delGAAA rs80357867 and c.4986+6T>C rs80358086) and the BRCA2 (c.6445_6446delAT rs80359592) genes for breast cancer prevention in Burkina Faso

BACKGROUND: The objective of this study is to search for mutations in the BRCA1 (c.5177_5180delGAAA and c.4986+6T>C) and BRCA2 genes (c.6445_6446delAT) in a population of women diagnosed with breast cancer.METHODS: This is a case-control study that involved 140 participants, including 70 patients with histologically diagnosed breast cancer and 70 healthy women without breast cancer. Mutations in the BRCA1 (rs80357867, rs80358086) and BRCA2 (rs80359592) genes were tested by real-time PCR. The 95% confidence interval Odds Ratio (OR) was used to estimate the associations between specific genotypes and breast cancer.RESULTS: The study revealed that no mutations were detected for rs80359592. Similarly, no reference allele (TTTC/TTTC) of rs80357867 was found in this study. However, the homozygous double mutant (-/) genotype of this rs80357867 was observed in 11.43% and 1.43% of patients and controls respectively, while 88.57% of patients and 98.57% of controls had a heterozygous deletion (TTTC/-). Concerning rs80358086, 8.57% of the patients had a heterozygous mutation (A/G) with no significantly risk association with occurrence of breast cancer (OR = 6.46; 95% CI: 0.75-55.21; p = 0.11). In addition, this heterozygous mutation was significantly associated with a family history of breast cancer (OR=128; 95% CI: 9.46-1730.93) and breast cancer risk in nonmultiparous women (OR=6; 95% CI: 1-35.90; p= 0.05) but no association with overweight/obesity (OR=1.66; 95% CI: 0.18-15.35; p=1).CONCLUSION: This study shows high frequencies of heterozygous mutation of rs80357867 and rs80358086 from patients. In Burkina Faso, these results could help with early diagnosis of breast cancer in patients

Linkage between ACE2 Gene Polymorphisms and SARS-CoV-2 infection in Burkina Faso, sub-Saharan Africa

The ACE2 gene polymorphisms (rs143936283, rs146676783, and rs4646116) in infected and noninfected persons by SARS-CoV-2 in Burkina Faso. Our cross-sectional study population comprised 137 SARS-CoV-2 infected persons and 181 non-infected persons. Three ACE2 gene polymorphisms rs143936283, rs146676783, and rs4646116, were genotyped using the real-time PCR standard TaqMan allelic discrimination technique. The association between SARS-CoV-2 infection and the polymorphisms were evaluated by a binary logistic regression. There was no association between the polymorphisms rs143936283, rs4646116 haplotypes, and SARS-CoV-2 infection in our study population. However, in the female population, the heterozygous genotype CT of rs146676783 increased by two and half the risk (OR=2.58 95%CI (1.2-5.48), p= 0.014) of being infected by SARS-CoV-2. Additionally, carrying the homozygous minor allele (genotype TT) of rs146676783 increased by more than five and half the risk (OR=5.57 95%CI (1.64-18.78), p=0.006) of being infected by SARS-CoV-2 among females. This study showed that the ACE2 gene variant rs146676783 was associated with an increased risk of being infected by SARS-CoV-2 in females, suggesting a need for further investigation to contribute to a better understanding of the African COVID-19 enigma

APOBEC3G expression and HIV-1 infection in Burkina Faso

APOBEC3G is a potent inhibitor of HIV-1 replication, and act by deaminating cytidines in uracil on the negative strand of the viral cDNA. In this case-control study, APOBEC3G expression in subjects’ naïve to HAART infected by HIV-1 and the effect of APOBEC3G polymorphism on its expression were evaluated. The results show that the HIV-1 infected carriers of the G minor alleles of the variant rs8177832 had a higher expression of APOBEC3G mRNA than the controls carriers of the G minor allele. APOBEC3G polymorphisms could play an important role in the modulation of the HIV-1 dissemination

Human immunodeficiency virus type 1 drug resistance in a subset of mothers and their infants receiving antiretroviral treatment in Ouagadougou, Burkina Faso

The emergence of HIV-1 drug resistance (HIVDR) is a public health problem that affects women and children. Local data of HIVDR is critical to improving their care and treatment. So, we investigated HIVDR in mothers and infants receiving antiretroviral therapy (ART) at Saint Camille Hospital of Ouagadougou, Burkina Faso. This study included 50 mothers and 50 infants on ART. CD4 and HIV-1 viral load were determined using FACSCount and Abbott m2000rt respectively. HIVDR was determined in patients with virologic failure using ViroSeq HIV-1 Genotyping System kit on the 3130 Genetic Analyzer. The median age was 37.28 years in mothers and 1.58 year in infants. Sequencing of samples showed subtypes CRF02_AG (55.56%), CRF06_cpx (33.33%) and G (11.11%). M184V was the most frequent and was associated with highlevel resistance to 3TC, FTC, and ABC. Other mutations such as T215F/Y, D67N/E, K70R, and K219Q were associated with intermediate resistance to TDF, AZT, and 3TC. No mutation to LPV/r was detected among mothers and infants. The findings of HIVDR in some mothers and infants suggested the change of treatment for these persons

No correlation between the variants of exostosin 2 gene and type 2 diabetes in Burkina Faso population

Recent genome-wide association studies and replication analyses have reported the association of variants of the exostosin- 2 gene (EXT2) and risk of type 2 diabetes (T2D) in some populations, but not in others. This study aimed to characterize the variants rs1113132, rs3740878 and rs11037909 of EXT2 and to determine the existence of a possible correlation with T2D in Burkina Faso. It is a case-control study undertaken in Burkina Faso in the city of Ouagadougou at the Hospital of Saint Camille of Ouagadougou from December 2014 to June 2015. It relates to 121 type 2 diabetes cases and 134 controls. The genotyping of these polymorphisms was done by real-time PCR using the allelic exclusion method with TaqMan probes. The minor allele frequencies (MAFs) was almost identical in diabetic and control subjects for the all three Single Nucleotide Polymorphisms (SNPs) with no statistical significance, p0.05: rs1113132 (OR=0.89; p=0.82); rs11037909 (OR=0.89; p=0.74) and rs3740878 (OR=1.52; p=0.42). None of the three polymorphisms studied was associated with the risk of DT2. However, an association between the BMI, age and type 2 diabetes was noted. The variants of EXT2 would not be associated to the risk of T2D in the African black population of Burkina Faso

INSIGHTS INTO THE INTERPLAY BETWEEN KIR GENE FREQUENCIES AND CHRONIC HBV INFECTION IN BURKINA FASO

Background/Objective: The receptors of natural killer cells "Killer Cell Immunoglobulin-Like Receptor" (KIR) regulate the activity of Natural killer cells in the innate response against viral infections. To date there is no accurate method to identify high risk groups for cirrhosis and HCC in Sub-Saharan Africa. Therefore, this investigation was undertaken to assess the association between KIR genes frequencies and chronic infection HBV infection in Burkina Faso’s population. Methods: Chronic HBV carriers and healthy patients were selected for this study. The viral load for HBV were performed to confirm the serological status for HBV of the studied cohort. In addition, SSP-PCR was used to characterize the frequencies of KIR genes. Results: The study suggested that inhibitory genes KIR2DL2, KIR2DL3 and activator gene KIR2DS2 (p˂0.001 for all and OR = 2.82; 2.48 and 3.84 respectively) might be associated with chronic stages of HBV infection.  While inhibitory genes KIR3DL1 (p = 0.0018 OR = 0.49), KIR3DL2 (p = 0.005 OR = 0.40), the activator gene KIR2DS1 (p = 0.014 OR = 0.47) and the pseudo gene KIR2DP1 (p = 0.011 OR = 0.49) could be associated with immunity against HBV infection. Patients who carried the KIR3DL2 gene had a high HBV viral load compared to the rest of the study population. Conclusion: Our data showed an evidence of correlation between the propensity of developing chronic HBV infection and certain KIR gene frequencies and that KIR3DL1, KIR3DL2, KIR2DS1 and KIR2DP1 might confer a protective status against chronic HBV infection in Burkina Faso’s patients

Prevention of mother-to-child transmission of hepatitis B virus in Burkina Faso: Screening, vaccination and evaluation of post-vaccination antibodies against hepatitis B surface antigen in newborns

The low rate of screening for hepatitis B virus (HBV) in pregnant women is a highrisk factor for its vertical transmission. The objectives of this study were: i) to screen pregnant women for HBV infection; ii) vaccinate all children from birth against HBV regardless their mother HBV status; and iii) evaluate after 7 months of birth the level of their AbHBs among babies who received HBV vaccine at birth. Serological markers of HBV (HBsAg, HBeAg, AbHBs, AbHBe, and AbHBc) were determined on venous blood samples from 237 pregnant women and their children using the Abon Biopharm Kit. One hundred and two (102) children received the three doses of the EUVAX B® vaccine respectively at birth, two months and four months of life. Seven months after delivery, venous blood samples were collected from mothers and their children. Antibodies against hepatitis B surface antigen (AbHBs) were measured in vaccinated children using the ELISA Kit AbHBs Quantitative EIA. DNA extraction was performed on samples from HBV-seropositive mothers and their children using the Ribo Virus (HBV Real-TM Qual) Kit and for Real Time PCR, the HBV Real-TM Qual Kit was used. Serological diagnosis in pregnant women revealed 22 (9.28%) hepatitis B surface antigen (HBsAg) positive samples of which 21 were positive for viral DNA by real-time PCR. Among the 22 HBsAg+ women, five (05) transmitted the virus to their children with a vertical transmission rate of 22.73%. A transmission rate of 23.81% (5/21) was found with the PCR method. Analysis of AbHBs levels revealed that 98.31% of the children had an average concentration of 218.07 ± 74.66 IU/L, which is well above the minimum threshold for protection (11 IU/L). This study has confirmed that vertical transmission of HBV is a reality in Burkina Faso and that vaccination at birth would significantly reduce this transmission