Trypanosome infections in animals from tsetse infected areas of Cameroon and their sensitivity and resistance molecular profiles for diminazene aceturate and isometamidium chloride.

Monitoring and assessment of control strategies for African trypanosomoses' elimination require not only updating data on trypanosome infections, but also to have an overview on the molecular profiles of trypanocides resistance in different epidemiological settings. This study was designed to determine, in animals from six tsetse-infested areas of Cameroon, the prevalence of trypanosome infections as well as the diminazene aceturate (DA) and isometamidium chloride (ISM) sensitivity/resistance molecular profiles of these trypanosomes. From 2016 to 2019, blood was collected in pigs, dogs, sheep, goats and cattle from six tsetse infested areas of Cameroon. DNA was extracted from blood and trypanosome species were identified by PCR. The sensitivity/resistance molecular profiles of trypanosomes to DA and ISM were investigated using PCR-RFLP. From 1343 blood samples collected, Trypanosoma vivax, Trypanosoma congolense forest and savannah, Trypanosoma theileri and trypanosomes of the sub-genus Trypanozoon were identified. The overall prevalence of trypanosome infections was 18.7%. These prevalence vary between trypanosome species, animal taxa, within and between sampling sites. Trypanosoma theileri was the predominant species with an infection rate of 12.1%. Trypanosomes showing resistant molecular profiles for ISM and DA were identified in animals from Tibati (2.7% for ISM and 65.6% for DA) and Kontcha (0.3% for ISM and 6.2% for DA). No trypanosome carrying resistant molecular profile for any of the two trypanocides was detected in animals from Fontem, Campo, Bipindi and Touboro. Mixed molecular profiles of sensitive/resistant trypanosomes were detected in animals from Tibati and Kontcha. Results of this study highlighted the presence of various trypanosome species as well as parasites carrying sensitive/resistant molecular profiles for DA and ISM in animals of tsetse infested areas of Cameroon. They indicate that the control strategies must be adapted according to epidemiological settings. The diversity of trypanosomes indicates that AAT remains a serious threat for animal breeding and animal health in these tsetse infested areas.

Molecular characterization of antimicrobial resistance related genes in E. coli, Salmonella and Klebsiella isolates from broilers in the West Region of Cameroon.

BACKGROUND: Antibiotic resistance has become an enduring threat to human health. This has prompted extensive research to identify the determinants responsible in a bid to fight the spread of resistance and also develop new antibiotics. However, routine procedures focus on identifying genetic determinants of resistance only on phenotypically resistant isolates. We aimed to characterise plasmid mediated resistance determinants in key Enterobacteriaceae isolates with differential phenotypic susceptibility profiles and evaluated the contribution of resistance genes on phenotypic expression of susceptibility. METHODS: The study was carried out on 200 Enterobacteriaceae isolates belonging to the genera E. coli, Salmonella, and Klebsiella; 100 resistant and 100 susceptible to quinolones, aminoglycosides, and ESBL-producing as determined by disk diffusion. Reduced susceptibility in susceptible isolates was determined as an increased MIC by broth microdilution. Plasmid-borne resistance genes were sought in all isolates by endpoint PCR. We performed correlations tests to determine the relationship between the occurrence of resistance genes and increased MIC in susceptible isolates. We then used the notion of penetrance to show adequacy between resistance gene carriage and phenotypic resistance as well as diagnostic odds ratio to evaluate how predictable phenotypic susceptibility profile could determine the presence of resistant genes in the isolates. RESULTS: Reduced susceptibility was detected in 30% (9/30) ESBL negative, 50% (20/40) quinolone-susceptible and 53.33% (16/30) aminoglycoside-susceptible isolates. Plasmid-borne resistance genes were detected in 50% (15/30) of ESBL negative, 65% (26/40) quinolone susceptible and 66.67% (20/30) aminoglycoside susceptible isolates. Reduced susceptibility increased the risk of susceptible isolates carrying resistance genes (ORs 4.125, 8.36, and 8.89 respectively for ESBL, quinolone, and aminoglycoside resistance genes). Resistance gene carriage correlated significantly to reduced susceptibility for quinolone and aminoglycoside resistance genes (0.002 and 0.015 at CI95). Gene carriage correlated with phenotypic resistance at an estimated 64.28% for ESBL, 56.90% for quinolone, and 58.33% for aminoglycoside resistance genes. CONCLUSIONS: A high carriage of plasmid-mediated genes for ESBL, quinolone, and aminoglycoside resistance was found among the Enterobacteriaceae tested. However, gene carriage was not always correlated with phenotypic expression. This allows us to suggest that assessing genetic determinants of resistance should not be based on AST profile only. Further studies, including assessing the role of chromosomal determinants will shed light on other factors that undermine antimicrobial susceptibility locally.

Patterns of Antibiotic Resistance in Enterobacteriaceae Isolates from Broiler Chicken in the West Region of Cameroon: A Cross-Sectional Study.

Background: The emergence of multidrug-resistant food-borne pathogens of animal origin including Enterobacteriaceae is a growing concern. Identifying and monitoring resistance in isolates from human-related environments are of clinical and epidemiological significance in containing antimicrobial resistance. This study aimed to contribute towards the fight against antibiotic resistance and ameliorate the management/treatment of Enterobacteriaceae-linked diseases in Cameroon. Methods: Cloacal swabs from healthy broilers were enriched in buffered-peptone-water and cultured on EMB agar. Antibiotic susceptibility was tested on Mueller-Hinton-Agar by disc diffusion. Plasmid-borne genes for extended-spectrum beta lactamase (ESBL) and resistance to Quinolones (PMQR) and Aminoglycosides were detected by standard endpoint polymerase chain reaction (PCR). Results: A total of 394 isolates were identified belonging to 12 Enterobacteriaceae genera, the most prevalent were Escherichia coli (81/394 = 20.56%), Salmonella spp (74/394 = 18.78%), and Klebsiella spp (39/394 = 9.90%) respectively. Overall, 84/394 (21.32%) were ESBL producers, 164/394 (41.62%) were resistant to quinolones, 66/394 (16.75%) resistant to aminoglycosides with 44.0% (173/394) expressing MDR phenotype. Poor hygiene practice (OR 2.55, 95% CI: 1.67, 3.89, p=0.001) and rearing for >45 days, (OR = 7.98, 95% CI: 5.05, 12.6, p=0.001) were associated with increased carriage of MDR. Plasmid-borne resistance genes were detected in 76/84 (90.48%) of ESBL-producing isolates, 151/164 (92.07%) quinolone resistant isolates and 59/66 (89.39%) aminoglycoside resistant isolates with co-occurrence of two or more genes per isolate in 58/84 (69.05%) of ESBLs, 132/164 (80.49%) of quinolone resistant isolates and 28/66 (42.42%) of aminoglycoside resistant isolates. Conclusion: This study found high carriage and widespread distribution of Enterobacteriaceae with ESBL and MDR in broiler chicken in the West Region of Cameroon. Most PMQR genes in bacteria were found at levels higher than is seen elsewhere, representing a risk in the wider human community.

Aetiology and risk factors of bacterial gastroenteritis among febrile outpatients at the Dschang District Hospital, West Region of Cameroon: a cross-sectional study.

OBJECTIVES: To investigate the bacterial aetiologies and associated risk factors of gastroenteritis among typhoid suspected cases. DESIGN: Cross-sectional study. SETTING: This study was conducted at Dschang District Hospital of the Menoua Division, West Region of Cameroon, between April-November 2019 and June 2020. PARTICIPANTS: Participants aged ≥2 years (mean 34±18.77 years) and of both sex suspected of having typhoid fever were included, while non-suspected typhoid cases were excluded. Self-reported sociodemographic and health information at recruitment was obtained from 556 participants. METHODS: Collected stool samples were examined macroscopically and microscopically and subjected to culture. After culture, Gram staining was performed, followed by biochemical testing and characterisation using the Analytical Profile Index (API-20E) test kit. INTERVENTIONS': No intervention was done during the period of study. OUTCOME MEASURES: We identified bacterial causing gastroenteritis, and associated risk factors calculated using binary regression, adjusting for sociodemographic and health variables. RESULTS: Of 556 patients, 74.28% tested positive for gastroenteritis. Among pathogens responsible for gastroenteritis, Escherichia coli was found to be the main cause (21.1%), followed by Salmonella typhi (10.4%), Citrobacter diversus (8.2%), and Proteus mirabilis (8.2%), Proteus vulgaris (7.3%), whereas Citrobacter spp and Yersinia enterocolitica were less represented among pathogens causing the disease among patients. A significant difference (p=0.002) was observed between abdominal pain and all the micro-organisms isolated from the patients. Patients having primary level of education were significantly associated (p=0.017; 3.163 (95% CI 1.228 to 8.147)) with the prevalence of gastroenteritis. Consumption of beverages (Wald statistic: 4.823; OR: 2.471; 95% CI (1.102 to 5.539); p=0.028), use of modern toilet (Wald statistic: 4.471; OR: 1.723; 95% CI (1.041 to 2.852); p=0.034) were strongly associated with gastroenteritis and rearing of bird (Wald statistic: 4.880; OR: 0.560; 95% CI (0.335 to 0.937); p=0.027), was found to be protective. CONCLUSION: Acute bacterial gastroenteritis is a significant cause of morbidity in Dschang, with the prevalence of 74.28%. Many pathogens accounted for gastroenteritis, and E. coli (21.1%) could be a major cause, followed by S. typhi (10.4%), C. diversus (8.2%), P. mirabilis (8.2%), P. vulgaris (7.3%), whereas Citrobacter spp and Y. enterocolitica were less represented. Gastroenteritis was highly associated with primary level of education, consumption of beverages, use of modern toilet while rearing of birds was unexpectedly found to be protective against Gastroenteritis. Further characterisation is planned.

A Cross-Sectional Comparative Study of the Performance of the Widal Test and the Typhidot Immunoassay for Typhoid Fever Diagnosis in the West Region of Cameroon.

BACKGROUND: The diagnosis of typhoid fever based on the Widal slide agglutination test remains a major hurdle in developing countries due to varied perceptions of the value of the Widal test in determining clinical decision-making. We undertook a study to evaluate the diagnostic performance of the Widal test and the Typhidot immunoassay in patients suspected of having typhoid fever in the Menoua division, West Region of Cameroon. METHODS: Blood and stool samples were collected from 558 consenting febrile patients on the basis of suspicion of typhoid fever. These patients attended three district health services of the Menoua division between April 2018 and September 2019. These patients had clinical symptoms suggestive of typhoid fever as determined by their consultant. Serum was used for the Widal slide agglutination test and for the Typhidot rapid immunoassay test based on manufacturer's guidelines. A composite reference of fever plus positive coproculture for Salmonella typhi and Salmonella paratyphi was used as the reference. The sensitivity, specificity, and predictive values of the positive and negative tests were calculated as well as Cohen's kappa for agreement between the two tests. RESULTS: Of 558 patients, 12.90% tested positive for the reference method, 57.17% tested positive for the Widal slide agglutination test, while 15.59% were positive for Typhidot-IgM. The overall sensitivity, specificity, and predictive values of the positive and negative tests were 80.56%, 94.03%, 66.6%, and 97.03% for Typhidot-IgM and 94.44%, 48.35%, 21.32%, and 98.33% for the Widal slide agglutination test, respectively. Cohen's kappa estimates were 0.1660 (0.121-0.211) and 0.386 (0.312-0.460) for the Widal test and Typhidot immunoassay for 53.6% and 76.16% agreements of all observations, respectively. CONCLUSION: The Widal test was found to have a lower predictive value for the diagnosis of typhoid fever in our setting. However, the Typhidot test, although better, was not ideal. Diagnosis of typhoid fever should therefore rely on adequate clinical suspicion and a positive Typhidot test to improve the clinical management of typhoid fever in our setting.

The Effect of HBV/HCV in Response to HAART in HIV Patients after 12 Months in Kumba Health District in the South West Region of Cameroon.

Hepatitis B (HBV) and C (HCV) are two among the numerous forms of infections whose clinical degeneration, morbidity-mortality and low immune responsiveness in people living with human immunodeficiency virus (HIV) are highly evident. Co-infection of HIV with HBV and HCV has been associated with reduced survival, increased risk of progression to liver diseases and increased risk of hepatotoxicity associated with antiretroviral therapy (ARV). We carried out biochemical, immunological, virological and clinical analysis of hepatitis B and C positive HIV patients as well as some HIV positive individuals receiving antiretroviral therapy in Kumba Health District to evaluate the immune response to the ARV therapy and identified risk factors associated with the treatment outcomes. A total of 52 HIV patients, 36 HIV/HBV and 12 HIV/HCV patients were involved in this study. We performed CD4 counts, viral load test, analyzed ALAT/ASAT, albumin, bilirubin, and creatinine and measured the weights of HIV patients, HIV/HBV and HIV/HCV enrolled for not more than one year in Kumba Health District. The results were analyzed to evaluate the immune response and possible risk factors associated with the treatment outcomes. The mean increase in weight in participants of all groups over 12 months (17.12 kg) was greater than the mean increase in CD4 (8.92 cell/mm3). However, the mean decrease in viral loads over a 12 months was also very high (1035.17 copies/mL). There was a significant change in the mean values from baseline for all the three variables (p < 0.0001). HIV disease outcomes following HAART (high active antiretroviral therapy) do not appear to be adversely affected by HBV or HCV co-infection, except for slightly poorer CD4 count responses in HIV/HCV co-infected patients. Concerning the renal and liver functions, all the biomarkers witnessed a decrease in patients of all groups in response to HAART over time, with a more rapid decrease in mono-infected patients as compared with those co-infected with HBV but the case was contrary for those co-infected with HCV. Co-infection with HBV or HCV was relatively common among HIV infected participants in Kumba Health District. There were differences in response to HAART between the mono-infected compared with the co-infected, taking into consideration the weight, CD4 count, and viral load. In addition, there was also a variation in the different biomarkers of liver and renal function between mono-infected and co-infected patients.

Cross-sectional hospital-based study on the seroprevalence of hepatitis B virus markers among healthcare workers, NWR, Cameroon.

BACKGROUND: Hepatitis B virus (HBV) infection is a major public health issue worldwide, with about 257 million people reported to be chronic carriers by the WHO fact sheet updated in 2018. HBV can be contracted via direct contact with infected body fluid and infection is almost always asymptomatic. Although healthcare workers (HCWs) are at high risk of HBV infection, little is known about the prevalence of the various HBV markers among HCWs in Cameroon. The present study was taken to evaluate the prevalence of different HBV serological markers among HCWs in the North-West Region of Cameroon. METHODS: This cross-sectional hospital-based study was carried out between April and September 2017 during which 395 HCWs were recruited. The serum of the HCWs were tested for the presence of HBV core antibody, hepatitis B surface antibody, hepatitis B e antibody and hepatitis B surface antigen using Monalisa ELISA kits produced by BIO-RAD laboratories. Data were analysed using SPSS V.20.0. RESULTS: Among the 395 participants, 270 (68.4%) of them were females, 187 (47.3%) had been exposed to HBV, 145 (36.7%) had resolved the infection, 42 (10.6%) were current HBV carriers, 10 (2.5%) were infective, 36 (9.1%) were vaccinated and 172 (43.5%) were still susceptible. Exposure to HBV, past infection and susceptibility were significantly associated with age while the rate of vaccination was significantly associated with the job of the HCW in the health facilities. CONCLUSION: The prevalence of HBV exposure and infection among HCWs obtained in this study was high while the level of vaccination in this at-risk population was low. Adequate steps should be taken to sensitise this population on HBV and the vaccination procedure.

Group B Streptococcus colonisation, prevalence, associated risk factors and antimicrobial susceptibility pattern among pregnant women attending antenatal care at Dschang District Hospital, West Region of Cameroon: A hospital-based cross-sectional study.

BACKGROUND: Group B Streptococcus (GBS), also known as Streptococcus agalactiae, is a Gram-positive bacterium known for its ability to colonise the vaginal and rectal areas of the mother and is a leading cause of neonatal mortality and morbidity. This study aimed at determining the prevalence, associated risk factors and antimicrobial susceptibility of GBS colonisation among pregnant women attending antenatal care (ANC) at Dschang District Hospital. METHODS: This hospital-based cross-sectional study used a multistage sampling method to recruit a total of 621 consented pregnant women who attended ANC in Dchang District Hospital. The 621 Participants at 23.5 ± 6.4 weeks gestation each completed a questionnaire and vaginal swabs were collected for GBS analysis. RESULTS: Among the 621 pregnant women that were included in this study, the colonisation rate of GBS was found to be 8.69%. Induced abortion (odds ratio [CI] = 3.09, 95% [1.56-6.21]), Spontaneous abortions (OR = 2.82, 95% CI 1.14-7.29), Stillbirth (OR [CI] = 7.75, 95% [2.61-21.71]), Fever (OR [CI] = 0.37, 95% [0.19-0.71]) and anaemia (OR [CI] = 0.22, 95% [0.12-0.43]) were found to be factors associated with GBS colonisation. CONCLUSION: Our findings suggest that we found that, induce abortion, spontaneous abortions and stillbirths were highly associated rates of GBS colonisation, while fever and anaemia were associated with lower rates of GBS colonisation. Further longitudinal research is needed to establish the causal relationship and its biological mechanisms.

Molecular identification of diminazene aceturate-resistant strains of Trypanosoma congolense in naturally infected domestic animals of Yoko in the centre region of Cameroon.

African animal trypanosomiases (AAT) remain the major constraint for livestock production, agriculture and food security in Africa. Although several control measures have been developed to fight AAT, the use of trypanocides remains the main strategy in most affected poor and rural communities. However, several studies have highlighted drug-resistant-trypanosome infections in many African countries, though this phenomenon is still not well described. This study aims to detect trypanosome species and the molecular profiles of drug-resistant-trypanosomes in naturally infected domestic animals of Yoko in the centre region of southern Cameroon. Therefore, in October 2017, 348 animals were blood sampled. The level of packed cell volume (PCV) was evaluated in each animal and trypanosome infections were investigated with the capillary tube centrifugation technique (CTC). Thereafter, DNA was extracted from blood samples and different trypanosome species were identified by PCR. The resistant/sensitive molecular profiles of trypanosomes for diminazene aceturate (DA) and isometamidium chloride (ISM) were investigated by PCR-RFLP. About 18.4% (64/348) of animals analyzed by PCR were found with trypanosome infections including Trypanosoma vivax, Trypanosoma brucei s.l. and Trypanosoma congolense forest and savannah. Trypanosoma congolense savannah was the predominant species with an infection rate of 15.2%. Between villages, significant (p˂0.0001) differences were found in the overall trypanosome infection rates. No molecular profile for ISM resistant-trypanosomes was identified. Conversely, about 88.9% (40/45) of T. congolense positive samples have shown molecular profiles of DA-resistant strains while the remaining 11.1% (5/45) showed mixed molecular profiles of resistant/sensitive strains. Results showed that the molecular profiles of DA-resistant strains of T. congolense in domestic animals of Yoko were widespread. This data needs to be confirmed by testing in vivo the drug susceptibilities of the trypanosome strains herein detected. In conclusion, appropriate future control measures are required. In addition to the intensification of vector control, ISM is advised for the treatment of animals infected by trypanosomes.

Immunomodulatory Activity of Momordica charantia L. (Cucurbitaceae) Leaf Diethyl Ether and Methanol Extracts on Salmonella typhi-Infected Mice and LPS-Induced Phagocytic Activities of Macrophages and Neutrophils.

Infections due to Salmonella strains constitute one of the major health problems in humans, particularly in Africa. The use of traditional herbs has proven effective in reducing the incidence of infection in some high-risk groups. To assess the effects of Momordica charantia leaf extracts that influence blood infection, an in vitro study of the effect on macrophages and neutrophils and treatment of mouse model of S. typhi infection was done. Methanol and diethyl ether extracts were concerned by this study. In vitro study was to assess the effects of extracts on phagocytosis, and related intracellular killing mechanisms of macrophages were examined. Later, mobilization of leukocytes and production of antibodies against S. typhi were measured followed by quantitating cultures evaluation of the blood infection of orally inoculated mice with S. typhi. Ingestion or attachment of carbon particles, production of superoxide anion, nitric oxide, and that of lysosomal acid phosphatase by macrophages and neutrophils were significantly increased by methanol and diethyl extracts at concentrations ranging from 40 µg/ml to 640 µg/ml. Antibody titer and mobilization of leukocytes, particularly lymphocytes against S. typhi, were highly increased by both methanol and diethyl extracts at concentrations of 500 and 1000 mg/kg. At the same time, the extracts have reduced the rate of blood colonization in mice inoculated with 108 CFU of S. typhi for 28 days. Reduction in blood colonization or infection rates was similar for the levamisole mice group. The results of this study should prove that the leaves of Momordica charantia are useful for the treatment of infections by Salmonella strains and for the assessment of drugs for therapeutic intervention.

Knowledge, attitude and prevalence of hepatitis B virus among healthcare workers: a cross-sectional, hospital-based study in Bamenda Health District, NWR, Cameroon.

INTRODUCTION: Hepatitis B virus (HBV) is a bloodborne virus which can be transmitted via percutaneous and mucocutaneous exposure to infected body fluid. Healthcare workers (HCWs) who are continuously exposed to different body fluids are at an increased risk of contracting and transmitting this virus. It is thus important to evaluate the knowledge and attitude of HCWs towards HBV and the prevalence of HBV infection among them. METHODS: This cross-sectional study was carried out between April and September 2017. Overall, 398 HCWs were recruited for this study. Knowledge on the route of HBV transmission and attitude towards HBV were evaluated using a well-structured questionnaire. Hepatitis B surface antigen (HBsAg) positivity was obtained using the Monolisa HBsAg ULTRA kit (Bio-Rad). Data were analysed using SPSS V.20. RESULTS: Among the HCWs who participated in this study, 338 (84.9%) had heard of HBV, and 269 (67.6%) of them had adequate knowledge on the route of HBV transmission. Medical doctors were the most knowledgeable among biomedical workers and students (76.5%). The rate of stigma was highest among nurses (87, 38.8%). The prevalence of HBsAg positivity was high (42, 10.6%) given that there is an efficient and available vaccine. Overall, over 70% of HCWs invited to participate in this study responded. CONCLUSION: Knowledge on the route of HBV transmission was fair, and the level of stigmatisation of HBV-infected patients and the prevalence of HBV infection were high in this study. A sensitisation campaign should be carried out to educate HCWs on HBV, thus reducing the level of stigma associated with HBV as well as the probability of contracting HBV as a nosocomial infection.

Molecular identification of diminazene aceturate resistant trypanosomes in tsetse flies from Yoko in the Centre region of Cameroon and its epidemiological implications.

African animal trypanosomiases are caused by trypanosomes cyclically or mechanically transmitted by tsetse and other biting flies. Although molecular tools have been developed to identify drug-resistant trypanosomes in mammals, little or no investigation on drug-resistance has been undertaken on trypanosomes harbored by tsetse flies. Moreover, no data on mechanical vectors of African trypanosomes is available in most endemic areas of Cameroon. This study was designed to update our knowledge on the cyclical and mechanical vectors of African trypanosomes, and using molecular tools to identify different trypanosome species as well as diminazene aceturate resistant trypanosomes in tsetse flies trapped at Yoko in the Centre region of Cameroon. For this study, traps were used to catch tsetse and mechanical vectors of African trypanosomes. The flies trapped were counted and identified by sex and species. DNA was extracted from tsetse and species-specific primers were used to identify different trypanosome species. PCR-RFLP was used to detect diminazene aceturate resistant strains of Trypanosoma congolense. In all, 454 flies comprising 168 (37%) Tabanus spp., 71 (15.6%) Stomoxys spp. and 215 (47.4%) tsetse fly (i.e. 107 (49.8%) Glossina fusca congolensis, 71 (33%) Glossina fusca fusca and 37 (17.2%) Glossina palpalis palpalis) were trapped. Trypanosome infections were identified in 12.6% (27/215) of tsetse flies: 13 in G. f. congolensis, 6 in G. p. palpalis and 5 in G. f. fusca. From 24 T. congolense positive samples, PCR-RFLP was successful on 37.5% of the samples. Four samples (16.2%) harbored T. congolense strains that were resistant to diminazene aceturate while the remaining samples had drug-sensitive strains. These results show for the first time the applicability of molecular tools for the identification of drug-resistant trypanosomes in tsetse. They revealed the existence of diminazene aceturate resistant strains of T. congolense in the tsetse-infested area of Yoko in the Centre region of Cameroon. Detection of drug-resistant trypanosomes in tsetse may enable scientists to map with accuracy specific areas where these parasites are transmitted. With such mapping, control strategies against African trypanosomiases could be improved by adapting control measures according to drug resistance distribution.

A Cross Sectional Study of the Impact of Human Immunodeficiency Virus, Hepatitis B Virus and Hepatitis C Virus on Rheumatoid Factor Production.

OBJECTIVES: This study aims to investigate how human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) affect the production of immunoglobulin M (IgM)-rheumatoid factor (RF). PATIENTS AND METHODS: The study included 405 voluntary participants (139 males, 266 females; mean age 39.4±17.9 years; range 3 to 88 years) randomly recruited by a consecutive sampling technique in the main health facilities of the Center, East, Far North, Littoral and West regions of Cameroon. We excluded persons under treatment or hospitalized for any form of primary autoimmune disease. Blood samples were collected and used for serological analyses. We sought for the HIV antibodies (Ab); the core antibody (HBcAb), the surface antigen (HBsAg), and the replicative antigen (HBeAg) of the HBV; HCVAb of HCV and the IgM-RF. RESULTS: The prevalence of HIVAb was 7.61%, 38.7% for HBcAb, 5.43% for HBsAg, 1.26% for HBeAg and 6.41% for IgM-RF in the study population. The Far North region had the highest prevalence of IgM-RF (9.8%) and the Littoral region had the lowest prevalence (3.2%). The prevalence of RF was 6.7% and 5.7% for females and males, respectively (sex ratio of 2.25). The IgM-RF prevalence was 9.7%, 8.9%, 9.1%, and 27.8% in participants with positive serological results for HIVAb, HBcAb, HBsAg, and HCV, respectively. CONCLUSION: Infection by HIV and HBV showed to poorly stimulated IgM-RF production. However, IgM-RF was highly produced in HCV infected participants. Increased IgM-RF production may contribute to cytotoxicity in tissues or organs of HCV-infected patients, leading to the onset of autoimmune diseases.

Seroprevalence of Toxoplasma gondii IgG and IgM antibodies and associated risk factors in women of child-bearing age in Njinikom, NW Cameroon.

BACKGROUND: Toxoplasmosis is a widely distributed zoonotic disease, caused by the protozoan parasite Toxoplasma gondii. T. Infections can result in stillbirths, abortions or congenital defects during pregnancy, as well as toxoplasmic encephalitis in HIV/AIDS patients. This study aimed to determine the seroprevalence and risk factors for T. gondii infection in women seeking antenatal and medical care in the locality of Njinikom, North West of Cameroon. METHODS: We conducted a cross-sectional study from August to December 2014 consecutively enrolling 178 consenting women aged 15 to 49 years attending antenatal care or medical check-ups at the hospital. A questionnaire survey was administered to study participants and potential risk factors for Toxoplasma exposure sought. Venous blood was collected and serum from each participant analysed for T. gondii infection as evidenced by the presence of anti-T. gondii IgG and IgM antibodies detected using the indirect enzyme-linked immunosorbent assay (ELISA) technique. The proportion of anti-T. gondii antibody positivity calculated as the percentage of antibody seropositivity to T. gondii antigens. Predictors of T. gondii infection were analysed by univariate and multivariate regression and association with T. gondii seropositivity assessed. Epi-Info 3.5.4 was used for statistical analyses. A p < 0.05 was considered significant for all analyses. RESULTS: The seroprevalence of anti-T. gondii antibodies (IgM or IgG) were 54.5 % (97/178). Among seropositive women, 88.7 % (86/97), 30.9 % (30/97), and 19.6 % (19/97) were respectively seropositive for IgG antibody, IgM antibody and both IgM and IgG antibodies. Among the risk factors evaluated, only the consumption of raw or undercooked meat (p = 0.02) was observed to be an independent risk factor of T. gondii infection. The consumption of unwashed vegetables and fruits was significant (p = 0.01) only with simple logistic regression analysis. CONCLUSIONS: Our findings suggest recent T. gondii exposure is high in our study population, and may constitute a significant risk factor for stillbirths, abortions or congenital defects during pregnancy in women attending antenatal care, or toxoplasmic encephalitis in those who are immunosuppressed such as in HIV/AIDS. Education and screening of HIV-positive individuals and pregnant women for T. gondii infection may be important primary prevention strategies in this population.

Anti-Staphylococcus aureus activity of methanol extracts of 12 plants used in Cameroonian folk medicine.

BACKGROUND: The emergence of bacterial infections including those associated with Staphylococcus aureus causes a benefit of interest to medicinal plants as an effective means of control. The present study was designed to investigate the activities of 12 selected Cameroonian medicinal plants against S. aureus isolates. METHODS: The plant extracts were prepared by maceration in methanol at laboratory temperature. Qualitative phytochemical analysis was performed by chemical reaction methods. The broth microdilution method was used to evaluate the activities of plant extracts against 11 S. aureus clinical isolates. RESULTS: Dacryodes edulis was found to have significant antibacterial activity on all the S. aureus isolates (MIC = 64-256 µg/ml). Occimum gratissimum revealed significant inhibitory activity on 9 of the 11 isolates while Commelina erecta and Spilanthes filicaulis revealed similar results on 6 of the 11 clinical isolates. CONCLUSION: The present findings showed that D. eduli, O. gratissimum, C. erecta and S. filicaulis possess interesting inhibitory properties against S. aureus species. These plants could therefore be good candidates to overcome infectious diseases associated with these microorganisms.

Antibacterial activity of ethanolic extract and compounds from fruits of Tectona grandis (Verbenaceae).

BACKGROUND: Well known as teak, Tectona grandis is widely used in African folk medicine for its pharmacological relevance. In Cameroon, this species is a reputed laxative in the Northern Region while in the Western Region, it is used in the treatment of skin diseases and diarrhoea. MATERIALS AND METHODS: Separation and isolation of compounds were performed using different chromatographic methods while their structures were elucidated by spectroscopic techniques including MS and NMR, and by comparison of data with those reported in the literature. Isolated compounds as well as crude ethanol extract were tested for their antibacterial activities using broth micro-dilution method against four Gram negative bacteria strains Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (PA 01), Klebsiella pneumonia (ATCC 11296) and Escherichia aerogenes (ATCC 13048). RESULTS: Three known compounds were isolated, including two quinones and one triterpene. They were identified as tectograndone (1), 6-methyl-1,4-dihydroxyanthraquinone (2), and 2ß-hydroxyursolic acid (3) respectively. Crude ethanol extract showed good activity against the bacteria strains tested with MIC of 64-256 µg/mL. Among the isolated metabolites, 6-methyl-1,4-dihydroxyanthraquinone exhibited a strong activity against Escherichia aerogenes with MIC of 16 µg/mL, while tectograndone showed a moderate activity against Escherichia coli with MIC of 32 µg/mL. The antibacterial screening of the fruits of this plant as well as that of compounds 1 and 2 is reported herein for the first time. CONCLUSION: The research work presented here shows that Tectona grandis fruits possess compounds which could be developed in the treatment of bacterial diseases.

Immunomodulatory activity of methanol leaf extracts of Cameroonian medicinal plants.

BACKGROUND: Medicinal plants have been used for centuries and have become part of complementary medicine worldwide because of their health benefits. Some have been successfully used directly in the treatment and prevention of infectious diseases or indirectly by stimulating the immune system. In the present study, the immunomodulatory activity of the methanol extracts of Adenocarpus mannii, Caucalis melanantha, Ocimum gratissimum, Asystasia intrusa and Clematis chinensis leaves was investigated. METHODS: The extracts were prepared by maceration of dry leaves' powder in methanol. Phytochemical analysis was carried out by chemical reaction methods. The activity of plant extracts was evaluated in in vitro cell cultures by measuring their effect on nitric oxide production by peritoneal macrophages, the proliferation of lymphocytes and the cytotoxic effect on macrophages. The A. mannii extract was further evaluated at 50 and 100 mg/kg body weight in mice for the stimulation of delayed-type hypersensitivity (DTH) reactions and the ability to reverse the myelosuppression induced by cyclophosphamide. RESULTS: All the extract inhibited nitric oxide production by peritoneal macrophages, the highest activity was achieved with C. chinensis extract. However, these extracts did not significantly affect the viability of macrophages. A. mannii, A. intrusa and C. chinensis extracts exhibited stimulatory activity on peripheral blood lymphocytes, whereas C. melanantha and O. gratissimum extracts displayed inhibitory activity. In vivo, the A. mannii extract significantly increased the DTH reaction in mice from 50 mg/kg. This extract also showed a significant increase in the white blood cells and relative weight of the spleen and liver. CONCLUSIONS: These results suggest that the A. mannii, C. melanantha, O. gratissimum, A. intrusa and C. chinensis methanol extracts possess immunomodulatory activity. This constitutes additional data on the well-known biological properties of these plants.

Population genetic structure of Central African Trypanosoma brucei gambiense isolates using microsatellite DNA markers.

Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of microorganisms. Seven microsatellite markers were used here to characterize Trypanosoma brucei gambiense isolates from Central Africa sub-region in order to improve knowledge on the population genetic structure of this subspecies. These markers confirmed the low genetic polymorphism within Central African T. b. gambiense isolates from the same focus and strong differentiation between different foci. The presence of many multilocus genotypes of T. b. gambiense and the excess of heterozygotes found in this study play in favour of a clonal reproduction of this parasite. But some data may be indicative of a unique recombination event in one subsample. The high F(ST) value indicates low migration rates between T. b. gambiense subpopulations (foci). Very negative F(IS) suggests fairly small clonal population sizes of this pathogen in the different human trypanosomosis foci of Central Africa.