Drug Target Exploitable Structural Features of Adenylyl Cyclase Activity in Schistosoma mansoni.

The draft genome sequence of the parasitic flatworm Schistosoma mansoni (S. mansoni), a cause of schistosomiasis, encodes a predicted guanosine triphosphate (GTP) binding protein tagged Smp_059340.1. Smp_059340.1 is predicted to be a member of the G protein alpha-s subunit responsible for regulating adenylyl cyclase activity in S. mansoni and a possible drug target against the parasite. Our structural bioinformatics analyses identified key amino acid residues (Ser53, Thr188, Asp207 and Gly210) in the two molecular switches responsible for cycling the protein between active (GTP bound) and inactive (GDP bound) states. Residue Thr188 is located on Switch I region while Gly210 is located on Switch II region with Switch II longer than Switch I. The Asp207 is located on the G3 box motif and Ser53 is the binding residue for magnesium ion. These findings offer new insights into the dynamic and functional determinants of the Smp_059340.1 protein in regulating the S. mansoni life cycle. The binding interfaces and their residues could be used as starting points for selective modulations of interactions within the pathway using small molecules, peptides or mutagenesis.

Impact of malaria on hematological parameters in people living with HIV/AIDS attending the Laquintinie Hospital in Douala, Cameroon.

BACKGROUND: People living with HIV/AIDS (PLWHA) frequently have abnormal blood counts including anemia, leucopenia and thrombocytopenia. The role of infection with plasmodia on these hematological parameters in PLWHA is not well known. In this study we compared selected hematological parameters between malaria positive and negative PLWHA. METHODS: We conducted a cross-sectional study of PLWHA attending the Douala Laquintinie hospital. After obtaining consent, demographic and clinical data were obtained via a standardized questionnaire. Blood samples collected for hematological assays were run using an automated full blood counter. Malaria parasitaemia was determined by blood smear microscopy. RESULTS: A total of 238 adult PLWHA were enrolled, 48.3% of who were on antiretroviral therapy and 24.8% of whom had malaria parasitaemia. The respective mean (±SD) of hemoglobin level, RBC count, WBC count, platelet count, lymphocyte count and CD4+ T cell counts in malaria co-infected patients versus non-infected patients were: 10.8(±1.9) g/dl versus 11.4(±2.0) g/dl; 3,745,254(±793,353) cells/µl versus 3,888,966(±648,195) cells/µl; 4,403(±1,534) cells/µl versus 4,920(±1,922) cells/µl; 216,051(±93,884) cells/µl versus 226,792(±98,664) cells/µl; 1,846(±711) cells/µl versus 2,052(±845) cells/µl and 245(±195) cells/µl versus 301(±211) cells/µl. All these means were not statistically significantly different from each other. CONCLUSION: There was no significant difference in studied hematological parameters between malaria positive and negative PLWHA. These data suggest little or no impact of malaria infection. Hematological anomalies in PLWHA in this area need not be necessarily attributed to malaria. These need to be further investigated to identify and treat other potential causes.

In vitro Antifungal Susceptibility Patterns of Candida Albicans from HIV and AIDS Patients Attending the Nylon Health District Hospital in Douala, Cameroon.

HIV and AIDS are major public health problems in Cameroon where the HIV prevalence is 5.5%. Candidiasis is the leading opportunistic mycosis in HIV and AIDS patients. The objective of this study was to determine the in vitro antifungal susceptibility pattern of Candida albicans in HIV and AIDS patients to eight antifungal agents in the Nylon Health District of Douala in Cameroon. Three hundred and four HIV and AIDS patients were recruited between March and August 2007 to participate in a cross-sectional study. All subjects who fulfilled the inclusion criteria were enrolled. Informed consent was obtained from all subjects before samples were collected. Three samples comprising oral swabs, vagina/urethra swabs and a mid-stream urine were collected from each subject. Specimens were cultured on sabouraud dextrose agar and C. albicans isolates were identified using the germ tube technique. The disk diffusion method was used for antifungal susceptibility testing using eight antifungal agents. The prevalence of candidiasis in the study population was 67.8% (95% CI: 62.5-73.1%) and that of C. albicans was 42.8% (95% CI: 37.2-48.4%). Oral swabs had the highest prevalence of C. albicans followed by vaginal/urethral samples (52.6% vs. 29.7% respectively). Forty (30.8%) subjects had C. albicans infection at more than one collection site. There was a statistically significant difference in the infectivity of C. albicans with age, sex and site of infection (P<0.05). C. albicans isolates were most sensitive to ketoconazole (80%) followed by econazole (64.6%) while fluconazole and 5-flurocytosin recorded the poorest sensitivities (22.9% vs 24.6%, respectively). There was a statistically significant difference in the sensitivity pattern of antifungal agents with respect to the site of isolation of the organism (P<0.05). Ketoconazole is the drug of choice for the treatment of C. albicans infection in HIV and AIDS patients in the Nylon Health District of Douala, Cameroon.

In Vitro Antifungal Susceptibility Patterns of Candida Albicans from HIV and AIDS Patients Attending the Nylon Health District Hospital in Douala; Cameroon

HIV and AIDS are major public health problems in Cameroon where the HIV prevalence is 5.5. Candidiasis is the leading opportunistic mycosis in HIV and AIDS patients. The objective of this study was to determine the in vitro antifungal susceptibility pattern of Candida albicans in HIV and AIDS patients to eight antifungal agents in the Nylon Health District of Douala in Cameroon. Three hundred and four HIV and AIDS patients were recruited between March and August 2007 to participate in a cross-sectional study. All subjects who fulfilled the inclusion criteria were enrolled. Informed consent was obtained from all subjects before samples were collected. Three samples comprising oral swabs; vagina/urethra swabs and a mid-stream urine were collected from each subject. Specimens were cultured on sabouraud dextrose agar and C. albicans isolates were identified using the germ tube technique. The disk diffusion method was used for antifungal susceptibility testing using eight antifungal agents. The prevalence of candidiasis in the study population was 67.8 (95 CI: 62.5-73.1) and that of C. albicans was 42.8 (95 CI: 37.2-48.4). Oral swabs had the highest prevalence of C. albicans followed by vaginal/urethral samples (52.6 vs. 29.7) subjects had C. albicans infection at more than one collection site. There was a statistically significant difference in the infectivity of C. albicans with age; sex and site of infection (P0.05). C. albicans isolates were most sensitive to ketoconazole (80) followed by econazole (64.6) while fluconazole and 5-flurocytosin recorded the poorest sensitivities (22.9 vs 24.6; respectively). There was a statistically significant difference in the sensitivity pattern of antifungal agents with respect to the site of isolation of the organism (P0.05). Ketoconazole is the drug of choice for the treatment of C. albicans infection in HIV and AIDS patients in the Nylon Health District of Douala; Cameroon

Antimicrobial and toxicological activities of five medicinal plant species from Cameroon traditional medicine.

BACKGROUND: Infectious diseases caused by multiresistant microbial strains are on the increase. Fighting these diseases with natural products may be more efficacious. The aim of this study was to investigate the in vitro antimicrobial activity of methanolic, ethylacetate (EtOAc) and hexanic fractions of five Cameroonian medicinal plants (Piptadeniastum africana, Cissus aralioides, Hileria latifolia, Phyllanthus muellerianus and Gladiolus gregasius) against 10 pathogenic microorganisms of the urogenital and gastrointestinal tracts. METHODS: The fractions were screened for their chemical composition and in vivo acute toxicity was carried out on the most active extracts in order to assess their inhibitory selectivity. The agar well-diffusion and the micro dilution methods were used for the determination of the inhibition diameters (ID) and Minimum inhibitory concentrations (MIC) respectively on 8 bacterial species including two Gram positive species (Staphylococcus aureus, Enterococcus faecalis), and six Gram negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Shigella flexneri, Salmonella typhi) and two fungal isolates (Candida albicans, Candida krusei). The chemical composition was done according to Harbone (1976), the acute toxicity evaluation according to WHO protocol and the hepatic as well as serum parameters measured to assess liver and kidney functions. RESULTS: The chemical components of each plant's extract varied according to the solvent used, and they were found to contain alkaloids, flavonoids, polyphenols, triterpens, sterols, tannins, coumarins, glycosides, cardiac glycosides and reducing sugars. The methanolic and ethylacetate extracts of Phyllanthus muellerianus and Piptadeniastum africana presented the highest antimicrobial activities against all tested microorganisms with ID varying from 8 to 26 mm and MIC from 2.5 to 0.31 mg/ml. The in vivo acute toxicity study carried out on the methanolic extracts of Phyllanthus muellerianus and Piptadeniastrum africana indicated that these two plants were not toxic. At the dose of 4 g/kg body weight, kidney and liver function tests indicated that these two medicinal plants induced no adverse effect on these organs. CONCLUSION: These results showed that, all these plant's extracts can be used as antimicrobial phytomedicines which can be therapeutically used against infections caused by multiresistant agents. Phyllanthus muellerianus, Piptadeniastum africana, antimicrobial, acute toxicity, kidney and liver function tests, Cameroon Traditional Medicine.

Genital mycoplasmas in women attending the Yaoundé University Teaching Hospital in Cameroon.

Genital mycoplasmas are implicated in pelvic inflammatory diseases, puerperal infection, septic abortions, low birth weight, nongonococcal urethritis and prostatitis as well as spontaneous abortion and infertility in women. There is paucity of data on colonisation of genital mycoplasma in women and their drug sensitivity patterns. The aim of our study was to determine the prevalence of genital mycoplasmas (Ureaplasma urealiticum and Mycoplasma hominis) infection and their drug sensitivity patterns in women. A mycofast kit was used for biochemical determination of mycoplasma infection in 100 randomly selected female patients aged 19-57 years, attending the University of Yaoundé Teaching Hospital (UYTH) from March to June 2010. Informed consent was sought and gained before samples were collected. Genital mycoplasmas were found in 65 patients (65%) [95% CI=55.7-74.3%] and distributed as 41 (41%) [95% CI=31.4-50.6%] for U. urealiticum and 4 (4%) [95% CI=0.20- 7.8%] for M. hominis while there was co-infection in 20 women (20%) [95% CI=12.16-27.84%]. In our study, 57 (57%) [95% CI=47.3-67%] had other organisms, which included C. albicans (19 [19%]), G. vaginalis (35 [35%]) and T. vaginalis (3 [3%]). Among the 65 women with genital mycoplasma, the highest co-infection was with G. vaginalis (33.8%). Pristinamycine was the most effective antibiotic (92%) and sulfamethoxazole the most resistant (8%) antibiotic to genital mycoplasmas. We conclude that genital mycoplasma is a problem in Cameroon and infected women should be treated together with their partners.

Seroprevalence of Toxoplasma gondii infection among pregnant women in Cameroon.

Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, which has a wide geographical distribution. The congenital form results in a gestational form that can present a temporary parasiteamia that will infect the fetus. For this reason early diagnosis in pregnancy is highly desirable, allowing prompt intervention in cases of infection. The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies among pregnant women attending the Douala General Hospital. The study was carried out between March and July 2009, whereby 110 pregnant women were tested for IgG and IgM antibodies and information about eating habits and hygienic conditions was collected using a questionnaire. These women's ages ranged from 20-44 years old with an average of 29.9 years; the overall IgG and IgM seroprevalence was 70% and 2.73 % respectively. Seroprevalence was significantly high amongst women who ate raw vegetables (76.39%, P<0.05) and there was a significant trend towards a higher seroprevalence in women who did not have a good source of water (75.58%, P<0.05). This research showed that consumption of raw vegetables and poor quality drinking water are two risk factors associated with Toxoplasma gondii infection amongst pregnant women attending the Douala General Hospital in Cameroon.

Seroprevalence of Toxoplasma Gondii Infection among Pregnant Women in Cameroon

Toxoplasmosis is caused by an intracellular protozoan; Toxoplasma gondii; which has a wide geographical distribution. The congenital form results in a gestational form that can present a temporary parasiteamia that will infect the fetus. For this reason early diagnosis in pregnancy is highly desirable; allowing prompt intervention in cases of infection. The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies among pregnant women attending the Douala General Hospital. The study was carried out between March and July 2009; whereby 110 pregnant women were tested for IgG and IgM antibodies and information about eating habits and hygienic conditions was collected using a questionnaire. These women's ages ranged from 20-44 years old with an average of 29.9 years; the overall IgG and IgM seroprevalence was 70and 2.73respectively. Seroprevalence was significantly high amongst women who ate raw vegetables (76.39; P0.05) and there was a significant trend towards a higher seroprevalence in women who did not have a good source of water (75.58; P0.05). This research showed that consumption raw vegetables and poor quality drinking water are two risk factors associated with Toxoplasma gondii infection amongst pregnant women attending the Douala General Hospital in Cameroon

Genital Mycoplasmas in Women Attending the Yaounde University Teaching Hospital in Cameroon

Genital mycoplasmas are implicated in pelvic inflammatory diseases; puerperal infection; septic abortions; low birth weight; nongonococcal urethritis and prostatitis as well as spontaneous abortion and infertility in women. There is paucity of data on colonisation of genital mycoplasma in women and their drug sensitivity patterns. The aim of our study was to determine the prevalence of genital mycoplasmas (Ureaplasma urealiticum and Mycoplasma hominis) infection and their drug sensitivity patterns in women. A mycofast kit was used for biochemical determination of mycoplasma infection in 100 randomly selected female patients aged 19-57 years; attending the University of Yaounde Teaching Hospital (UYTH) from March to June 2010. Informed consent was sought and gained before samples were collected. Genital mycoplasmas were found in 65 patients (65) [95CI=55.7-74.3] and distributed as 41 (41) [95CI=31.4-50.6] for U. urealiticum and 4 (4) [95CI=0.20-7.8] for M. hominis while there was co-infection in 20 women (20) [95CI=12.16-27.84]. In our study; 57 (57) [95CI=47.3- 67] had other organisms; which included C. albicans (19 [19]); G. vaginalis (35 [35]) and T. vaginalis (3 [3]). Among the 65 women with genital mycoplasma; the highest co-infection was with G. vaginalis (33.8). Pristinamycine was the most effective antibiotic (92) and sulfamethoxazole the most resistant (8) antibiotic to genital mycoplasmas. We concluded that genital mycoplasma is a problem in Cameroon and infected women should be treated together with their partners