Cytochrome P450 CYP2B6*6 distribution among Congolese individuals with HIV, Tuberculosis and Malaria infection

Background: The cytochrome P450 CYP2B6*6 (CYP2B6 c.516G>T; rs3745274) is one of the genetic factors that alters the drug metabolism in antimalarial, antiretroviral and TB first-line drugs. In Central African populations, the distribution of the CYP2B6*6 variant is poorly documented. This study investigated the distribution of CYP2B6 c.516G>T variant among Congolese individuals. Methods: A total of 418 patients with HIV-1 mono-infection, HIV-1 and Tuberculosis coinfection and symptomatic P. falciparum malaria were genotyped for the CYP2B6 c.516G>T SNP using Restriction Fragment Length Polymorphism (RFLP). The allele frequencies and genotype distributions were determined. Results: The CYP2B6 c.516G>T was successfully analysed in 69% (288/418) of the study participants. Among the investigated individuals, the distribution of the major allele CYP2B6*G was 45% and the minor CYP2B6*T allele was 55%. Significant differences in genotype distribution were also observed among the studied individuals. The CYP2B6*GG (rapid metabolizer) genotype was observed in 17% (49/288) followed by CYP2B6*GT (intermediate metabolizer) 55% (159/288) and CYP2B6*TT (poor metabolizers) 28% (80/288). Conclusion: This study contributes to increasing understanding on population pharmacogenetics and may help policy makers regulate treatment guidelines in the Congolese population with a high burden of HIV, Malaria and TB. Keywords: CYP2B6, Cytochrome P 450, HIV, Malaria, Tuberculosis, Republic of Cong

An update on glucose-6-phosphate dehydrogenase deficiency in children from Brazzaville, Republic of Congo

Abstract Background Malaria transmission-blocking anti-malarial drugs, such as primaquine, offers an effective strategy for reducing the incidence of falciparum malaria. However, this drug induces haemolytic anaemia among glucose-6-phosphate dehydrogenase (G6PD) deficient individuals. The distribution of G6PD deficiency in Brazzaville, Republic of Congo and the association of G6PD deficiency with haemoglobin levels and blood cell counts were investigated. Methods A total of 212 febrile children were recruited for this study. Plasmodium falciparum diagnosis was conducted by microscopy and nested PCR. Sanger sequencing was used to assess G6PD deficiency by detecting 202G>A (rs1050828) and 376A>G (rs1050829) single nucleotide polymorphisms. Results Two hundred and twelve children were successfully genotyped for G6PD variants. Overall, 13% (27/212) of the children were G6PD deficient and 25% (25/100) females were heterozygous (11 BA− and 14 A+A−). The remaining 160 children had a normal G6PD genotype. The mean red blood and mean platelet counts were significantly lower in hemizygous male (G6PD A−) participants than in normal male (G6PD A+ or B) participants (p < 0.05). Conclusion This study gives an update on G6PD deficiency among Congolese children. Understanding the distribution of G6PD deficiency in other geographical regions is recommended before primaquine is adopted in the malaria control programme

Plasmodium falciparum infection in febrile Congolese children: prevalence of clinical malaria ten years after introduction of Artemisinin-combination therapies

dataset used in the paper

Production, Partial Purification and Based SDS-PAGE Profiles of Caseinolytic Enzyme in two Bacillus Strains Isolated from Fermented Cassava leaves "Ntoba mbodi" in Congo Brazzaville

Two Bacillus strains isolated from Ntoba mbodi : Bacillus megaterium (B.me NM 02) Bacillus licheniformis (B.li NM01), has shown a significant caseinolytic enzyme activity. We set optimization of growth and enzyme production conditions. Several parameters have been optimized: temperature, pH, various types of media, carbon and nitrogen sources. In both strains, growth is possible from 25 to 60 ° C with an optimum temperature at 37°C for B.li and at 35°C for B.me. Enzyme production was observed from 25 to 55 °C with an optimum temperature of 30 °C for B.li. Enzyme production was observed from 25 to 50 ° C with an optimum temperature of 35 ° C in B.me. For pH, growth and enzyme production can be at 5, 7 and 9 with an optimum at 7 for both strains. The LB medium is better for growth and enzyme production than TSB for B.li and B.me. Among the carbon sources used, fructose is better for growth after 48 hours of incubation in both strains (B.li: 0,93±0,001, B.me: 0,928±0,002), but for enzyme production fructose remains the best carbon source for B.li (14,33±1,24) , while starch is the best for B.me (14.66±1,24). Concerning nitrogen sources, in both strains the best source of growth is the yeast extracts (B.li: 0,969±0,015, B.me: 0,952±0,01). For enzyme production, the two sources can be used for B.li.(14,333±1,247) but for B .me (14,333±0,471) only the yeast extracts is the best as well as for growth and enzyme production. Furthermore, in both strains the produced enzyme was partially purified by using ammonium sulfate precipitation, and SDS-PAGE has been hold, profiles of specific bands are useful to give more information and differentiate the two strains

Prevalence of malaria among febrile patients and assessment of efficacy of artemether-lumefantrine and artesunate-amodiaquine for uncomplicated malaria in Dolisie, Republic of the Congo

International audienceAbstract Background In the Republic of the Congo, malaria represents a major public health problem affecting all age groups. A regular surveillance of the current efficacy of first-line anti-malarial drugs is required in the face of possible emergence and spread of artemisinin-resistant Plasmodium falciparum strains in Africa. The purpose of this study was to determine the prevalence of malaria among febrile patients of all ages and assess the efficacy of artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) in Congolese children. Methods Febrile patients of all ages were initially screened for malaria by both rapid diagnostic test (RDT) and microscopy. Patients less than 12 years of age, with parasitaemia ≥ 1000 asexual parasites of P. falciparum /µL of blood, without any signs of severity, were enrolled in a therapeutic efficacy study and treated after obtaining their parents' (or legal guardian’s) informed consent in two health centres in Dolisie. The patients were followed for 28 days in accordance with the 2009 World Health Organization standard protocol. If parasitaemia reappeared on or after day 7, the genetic profiles (genes expressing merozoite surface protein-1 [ msp1 ], merozoite surface protein-2 [ msp2 ], and glutamine-rich protein [ glurp ]) of pre-treatment and post-treatment isolates were compared by nested polymerase chain reaction (PCR) followed by capillary electrophoresis to make a distinction between recrudescence and re-infection. The clinical and parasitological outcome was analysed by the per-protocol method and Kaplan–Meier survival curves. Results A total of 994 febrile patients of all ages were screened by RDT and microscopy. Of 994 patients, 323 (32.5%) presented a positive RDT, and 266 (26.8%) were microscopy-positive. Based on microscopy as the reference diagnostic method, the sensitivity and the specificity of the RDT were 98.9 and 91.8%, respectively. The Cohen’s kappa coefficient was 0.86. A total of 121 children aged less than 12 years (61 in AL treatment group and 60 in ASAQ treatment group) were included in therapeutic efficacy study. Before PCR correction, the proportions of adequate clinical and parasitological response were 96.6% for AL and 86.0% for ASAQ in the per-protocol population ( P  0.05). Both treatments were well tolerated. Conclusions AL and ASAQ remain highly effective for the first-line treatment of uncomplicated P. falciparum malaria in Dolisie. Despite high efficacy of first- and second-line treatment, there is a continuing need to scale up effective malaria preventive interventions and vector control strategies in the country. Trial Registration Number: ACTRN12616001422415

HIV-1 genetic diversity and primary drug resistance mutations before large-scale access to antiretroviral therapy, Republic of Congo

Abstract Background In this work, we investigated the genetic diversity of HIV-1 and the presence of mutations conferring antiretroviral drug resistance in 50 drug-naïve infected persons in the Republic of Congo (RoC). Samples were obtained before large-scale access to HAART in 2002 and 2004. Methods To assess the HIV-1 genetic recombination, the sequencing of the pol gene encoding a protease and partial reverse transcriptase was performed and analyzed with updated references, including newly characterized CRFs. The assessment of drug resistance was conducted according to the WHO protocol. Results Among the 50 samples analyzed for the pol gene, 50% were classified as intersubtype recombinants, charring complex structures inside the pol fragment. Five samples could not be classified (noted U). The most prevalent subtypes were G with 10 isolates and D with 11 isolates. One isolate of A, J, H, CRF05, CRF18 and CRF37 were also found. Two samples (4%) harboring the mutations M230L and Y181C associated with the TAMs M41L and T215Y, respectively, were found. Conclusion This first study in the RoC, based on WHO classification, shows that the threshold of transmitted drug resistance before large-scale access to antiretroviral therapy is 4%

No polymorphisms in K13-propeller gene associated with artemisinin resistance in Plasmodium falciparum isolated from Brazzaville, Republic of Congo

Abstract Background In the Republic of Congo, artemisinin-based combinations have been recommended for the treatment of uncomplicated malaria since 2006. However, the emergence of resistant parasites again these combinations in Southeast Asia is a threat for the control of this disease, especially in sub-Saharan Africa where the weight of the disease is important. Indeed, polymorphisms in Plasmodium falciparum K13-propeller gene have been involved in variations of drug sensitivity of Plasmodium falciparum to artemisinin-based combinations. The aim of the current study is to determine the prevalence of mutations of this gene in isolates collected in three health centers in Brazzaville. Methods From May 2015 to May 2016, a total of 131, 259 and 416 samples from patients with suspected malaria were collected at the Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively. After DNA isolation, genotyping and sequencing of Plasmodium falciparum K13-propeller were performed in positive Plasmodium falciparum isolates identified after msp-2 gene genotyping. Results All 806 samples collected were msp-2 genotyped and Plasmodium falciparum infections were confirmed in 287 samples with 43, 85, 159 samples from Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively. Of these 287 msp-2 positives samples, K13-propeller nested PCR products were successfully obtained from 145 (50.52%) isolates and sequences were generated from 127(87.58%) nested products. None of mutations that were associated with ACTs resistance in Southeast Asia were detected on the samples from three different study sites from Brazzaville. However, one mutation type was observed at position 578, where alanine was substituted by serine (A578S) in two isolates (1.57%, 2/127), those from the Hôpital de Mfilou. No mutation was found in isolates from the two other sites. Conclusion The current study shows a very limited polymorphism in the K13-propeller gene in isolates from the Republic of Congo and K13 polymorphisms associate with ACT resistance are not present in this country. However, permanent and large surveillance of resistant parasite population using K13-propeller gene is recommended

A study on HIV, Syphilis, and Hepatitis B and C virus infections among female sex workers in the Republic of Congo

Abstract Background Female Sex Workers (FSWs) are considered to be at high risk for transmission of Sexually Transmitted Infections (STIs) and are defined as a priority of the national HIV/AIDS response in the Republic of Congo (RoC). However, no data are available regarding STIs in this group. This study aimed to determine the prevalences of HIV, syphilis and hepatitis B and C among FSWs in five cities in the country. Methods A cross-sectional study was conducted from November 2nd 2011 to May 15th 2012. Participants were recruited in Brazzaville, Pointe-Noire, Dolisie, Nkayi and Pokola using a respondent-driven sampling method. Results A total of 805 FSWs were recruited with an average age of 28.31 ± 9.15 years. The overall prevalences of HIV, syphilis, HBV and HCV were 7.50%, 2.20%, 4.20% and 0.70%, respectively. The age groups 35–39 (20.51% [0%–36.93%], p = 0.0057) and greater than 40 years (16.67% [0%–34.93%], P = 0.016) were positively associated with behaviors at high risk of HIV infection. For syphilis, the most infected age group was the one greater than 40 years, at 6.25% ([1.06% –72.37%] p = 0.04). Pointe-Noire was the most infected city for syphilis and HBV, with 5.15% (p = 0.0061) and 4.22% (p˂0.001), respectively. No risk factors were associated with HCV infection. FSWs practicing in mobile prostitution sites had a significantly higher infection rate (2.1% [0%–11.09%] p = 0.04). Conclusion This study shows that the prevalence of HIV and other STIs in FSWs is high. Therefore, a combination of individual and structural interventions could reduce the risk of an STI “reservoir” among this population