Research Note: Effect of a phlorotannin extract of the brown seaweed Ascophyllum nodosum as a potential control strategy against Campylobacter in broilers

Poultry is generally recognized as the main source of human campylobacteriosis and Campylobacter is highly prevalent at the farm level. To reduce the relative risk of human campylobacteriosis attributable to broiler meat, it is necessary to reduce Campylobacter loads in broiler ceca but to date, no effective, reliable and practical strategy is available. The marine environment is a rich source of original natural compounds exhibiting different biological activities. The objective of this study was to test a phlorotannin extract of the brown seaweed Ascophyllum nodosum as a potential control strategy against Campylobacter in broilers. Bactericidal activity has been demonstrated in vitro, on several Campylobacter spp. strains at a range of 0.06 to 0.47 mg/mL. Therefore, an in vivo trial in experimental facilities was performed to evaluate addition of 0.2% (w/w) of an A. nodosum extract to feed distributed at the end of rearing from day 31 to day 35, and to assess the effect on artificial Campylobacter jejuni colonization. No statistical differences in Campylobacter enumeration were observed between the treated and control groups. Another trial was performed in a commercial broiler flock. Feed containing the extract at 0.2% (w/w) (2 kg/t) was distributed during the last 5 days of rearing (day 33-day 38). No significant effects on Campylobacter colonization and on growth parameters were observed compared to the control group. Additional studies are needed to assess whether active polyphenols are found in the cecum.

Kaposi's disease in an HIV positive child, with probable contamination from his grandmother

Kaposi's disease in children with HIV is rarely reported in everyday practice. This is a case study of cutaneous Kaposi's disease revealing HIV in a 5-year-old child with polymorphic eruption of papules and nodules on the face, trunk, back, and limbs. Histopathological examination confirmed the diagnosis of Kaposi's disease. The child's HIV serology was positive with a CD4 count of 240/mm³, normochromic and normocytic anemia, and a hemoglobin level at 8.5 g/dl. It was found that the child, after early weaning from his HIV-negative mother, had repeatedly suckled his healthy grandmother, who had no skin lesions but was HIV1 positive. Both grandmother and child were referred for treatment in their locality. The case is noteworthy for the way in which the HIV1 virus infected the child during weaning and then being suckled by his grandmother. The child already had an initial dental flare that could have injured his grandmother. Thus, in our case, there is a contamination by HIV1 virus most likely from the grandmother and contamination by the HHV8 virus, source unidentified as a technical plateau was reached.

[RESAOLAB: West African network of laboratories to enhance the quality of clinical biology]

The Fondation Mérieux, in partnership with the Ministries of Health of Burkina Faso, Mali and Senegal, implemented for four years a project to reinforce the laboratory sector in the three participating countries: the RESAOLAB project (West African Network of Biomedical Analysis Laboratories).The objective of RESAOLAB project, in partnership with the WHO Office for West Africa and the West African Health Organization, was to strengthen the systems of biomedical laboratories to improve diagnostic services, access, monitoring and management of infectious diseases. Following the successful results achieved under the RESAOLAB project and due to the demand of the neighbour countries ministries, the RESAOLAB project is now extended to four other countries of the West African region: Benin, Guinea-Conakry, Niger and Togo. The RESAOLAB project has become the RESAOLAB programme, its purpose is to strengthen the quality of the medical biology services thanks to a regional and transversal approach.

Seroprevalence of Helicobacter pylori among Tunisian blood donors (outpatients), symptomatic patients and control subjects

OBJECTIVES

Helicobacter pylori is a worldwide infection, although little data are available in the Tunisian population. The aims of our study were to detect the prevalence of H. pylori in a blood-donor population (n=250) and in another population of hospital-consulting patients comprising 87 symptomatic patients and 59 controls, and to determine the factors that influence the prevalence.

MATERIALS AND METHODS

Study subjects answered a standardized questionnaire, and IgG anti-H. pylori and anti-cag were detected by ELISA. In the second population, culture and cagA polymerase chain reaction were performed.

RESULTS

The seroprevalence of H. pylori in blood donors was 64%, and 11% had anti-cag. All patients positive for anti-cag were also positive for anti-H. pylori antibodies. The seroprevalence of H. pylori was 99.3% in the hospital-consulting patients, of whom 55.5% were positive for anti-cag. The difference between the anti-cag and symptomatic patients (66.7%) and controls (39%) was significant. Symptomatic patients had a higher rate of anti-cag (66.7%) compared with the controls (39%) and blood donors (11%).

CONCLUSION

H. pylori seroprevalence in blood donors is low (64%) compared with symptomatic patients (99.3%), and anti-cag was statistically associated with symptomatic patients and pathology. Also, some environmental factors were correlated with H. pylori seroprevalence.

[Transmission of schistosomiasis in an urban population and prevalence of intestinal helminthiasis in Bamako, Mali ]

Parasitological, malacological and anthropological studies were performed to assess the prevalence of Schistosoma haematobium and S. mansoni in schoolchildren living in the suburban area of Bamako. A total of 1017 schoolchildren aged 6-14 years were selected in two different areas between September 1997 and December 1999. In Djikoroni, the prevalence of S. haematobium and S. mansoni was 80.7% (339/420) and 22.8% (85/372) respectively. There was no significant difference of prevalence and intensity of infection with S. haematobium between schools, gender and age (p > 0.05), whereas, those of S. mansoni were higher in the vicinity of (+/- 100 m from) major sites where infected Biomphalaria pfeifferi were found (p < 0.001). In Niomirambougou, S. haematobium was prevalent in 46.7% (279/597) and S. mansoni in 28.2% (134/475). Boys and children aged 11-14 years were more infected (p < 0.001). Associated intestinal helminths (Hymenolepis nana, Necator americanus and Ascaris lumbricoides) were relatively scarce (prevalence < 1%). The prevalences of schistosome infected snails intermediate host were relatively high, 49.3% (100/203) in B. pfeifferi, 20.6% (88/138) in B. truncatus and 24.1% (7/29) in B. globosus. We recorded a total of 2514 water contacts about which 1130 in December and 1384 in January. Most of the children, 42.9% (1077/2511) were attracted to water bodies for bathing, swimming and playing, suggesting the lack of recreational facilities in these areas. Developing local control programmes in schools located in the vicinity of water bodies would contribute to break the parasite transmission cycle in Bamako.

Antimalarial activity of extracts and alkaloids isolated from six plants used in traditional medicine in Mali and Sao Tome

Methanol and chloroform extracts were prepared from various parts of four plants collected in Mali: Guiera senegalensis (Gmel.) Combretaceae, Feretia apodanthera (Del.) Rubiaceae, Combretum micranthum (Don.) Combretaceae, Securidaca longepedunculata (Fres.) Polygalaceae and two plants -collected in Sao Tome: Pycnanthus angolensis (Welw.) Myristicaceae and Morinda citrifolia (Benth.) Rubiaceae were assessed for their in vitro antimalarial activity and their cytotoxic effects on human monocytes (THP1 cells) by flow cytometry. The methanol extract of leaves of Feretia apodanthera and the chloroform extract of roots of Guiera senegalensis exhibited a pronounced antimalarial activity. Two alkaloids isolated from the active extract of Guiera senegalensis, harman and tetrahydroharman, showed antimalarial activity (IC(50) lower than 4 microg/mL) and displayed low toxicity against THP1. Moreover, the decrease of THP1 cells in S phase of the cell cycle, after treatment with harman and tetrahydroharman, was probably due to an inhibition of total protein synthesis.

2-Acetyl-4H-benzothiazin-3(2H)-one

The title compound, C(10)H(9)NO(2)S, has a boat-shaped heterocyclic six-membered ring such that the S and N atoms lie essentially in the plane of the benzene ring while the remaining two C atoms are above this plane.

Structure and antiprotozoal activity of triterpenoid saponins from Glinus oppositifolius

Two new triterpenoid saponins, glinosides A and B, isolated from the aerial parts of Glinus oppositifolius, have been characterized by 1D, 2D, NMR and high-resolution mass spectral (HRMS) techniques. Their structures were established respectively as 16-O-(beta-arabinopyranosyl)-3-oxo-12,16 beta,21 beta,22-tetrahydroxyhopane for glinoside A and 16-O-(beta-arabinopyranosyl)-3-oxo-12,16 beta,22-trihydroxyhopane for glinoside B. Results presented evidence that fractions had a better antiplasmodial activity (IC50 = 31.80 micrograms/ml) than pure glinoside A (IC50 = 42.30 micrograms/ml).

Antimalarial activity of four plants used in traditional medicine in Mali

Mitragyna inermis (De Willd.) O. Kuntze Rubiaceae, Nauclea latifolia (Sm.) Rubiaceae, Glinus oppositofolius (Linn) Molluginaceae and Trichilia roka (Forsk.) Chiv. Meliaceae were investigated for their in vitro antimalarial activity. Leaves, roots and stem barks were submitted to aqueous, hydromethano and chloroform extractions and antimalarial activity was evaluated by microscopic and flow cytometric analysis. The results present evidence that the alkaloids contained in chloroform extracts and ursolic acid, purified from the hydromethanol extract of M. inermis induced a significant decrease of parasite proliferation. However, aqueous extracts, traditionally used for medication did not show high antimalarial activity. Statistical comparison between microscopic and cytometric analysis demonstrated the validity of this new technique for the screening of active antimalarial compounds isolated from plants.

New prenylated anthraquinones and xanthones from Vismia guineensis

From the roots of Vismia guineensis 23 structurally related compounds were isolated and identified. Ten of them are new constituents, namely 3-O-(2-hydroxy-3-methylbut-3-enyl)-emodin (1); 3-O-(2-methoxy-3-methylbut-3-enyl)-emodin (2); 1, 8-dihydroxy-3-(2-methoxy-3-methylbut-3-enyloxy)-6-methylx anthone (3); 1,8-dihydroxy-3-geranyloxy-6-methylxanthone (4); 1, 8-dihydroxy-3-isoprenyloxy-6-methylxanthone (5); 1,8-dihydroxy-3-(3, 7-dimethyl-7-methoxyoct-2-enyloxy)-6-methylxanthone (6); 3-O-(E-3-hydroxymethylbut-2-enyl)-emodin (7); 3-O-(3-hydroxymethyl-4-hydroxybut-2-enyl)-emodin (8); 1, 8-dihydroxy-3-(E-3-hydroxymethylbut-2-enyloxy)-6-methylxa nthone (9); and 1, 8-dihydroxy-3-(3-hydroxymethyl-4-hydroxybut-2-enyloxy)-6- methylxantho ne (10). Their structures were established by means of EIMS and a combination of homonuclear and heteronuclear 2D NMR techniques. Furthermore, an in vitro preliminary screening of antimitotic activity of all the isolated compounds was also evaluated.

Effects of some Malian medicinal plants on the respiratory tract of guinea-pigs

Crossopteryx febrifuga, Pteleopsis suberosa and Entada africana are used in Mali traditional medicine for fever and various respiratory diseases. We have investigated the effects of these three drugs in the form of a decoction on the respiratory tract using different experimental models. On citric acid-induced cough in guinea-pigs, the three drugs significantly decreased the number of coughs at the doses of 250 (P < 0.01), 500 (P < 0.05; P < 0.01) and 1000 (P < 0.01) mg kg(-1). The percent inhibition was respectively 62.86, 69.03 and 77.44% for C. febrifuga, 57.80, 53.90 and 61.40% for E. africana, and 37.13, 42.44 and 73.72% for P. suberosa. Codeine phosphate (10 mg kg(-1)) used as reference drug showed an inhibition of 76.32%. E. africana (1000 mg kg(-1)) reduced (65% inhibition) significantly (P < 0.05) bronchoconstriction induced by histamine (99.25% and 34.00% for control and extract, respectively). Furthermore, E. africana (1000 mg kg(-1)) provoked a bronchodilatation response when administered under basal conditions. On antigen-induced bronchospasm, C. febrifuga protected (54% inhibition) sensitized guinea-pigs with a pulmonary ventilation pressure (PVP) of 24.87% (control value < 55.00%). P. suberosa was inactive in both experimental models. The reference drug, disodium cromoglycate (10 mg kg(-1), i.v.) protected significantly (P < 0.05) with a PVP of 12.00% (78% of inhibition). This study confirmed the traditional use of these plants in the treatment of cough and other respiratory disorders.

[Synthesis and pharmacologic study of 1,5-dialkyl-1,5-benzodiazepine-2,4-dithiones]

The synthesis and psychotropic activity of 1,5-diakyl-1,5-benzodiazepine-2,4-dithiones (alkyl = methyl, ethyl and benzyl radicals) were studied. Alkylation reactions were performed in catalytic conditions by phase transfer. These reactions allowed us to isolate only one kind of product N-alkyl. Acute toxicity studies were conducted according to European protocols in two species of appropriate mammals in order to discover the lethal doses. The activity of the compounds on the CNS was then studied, using a battery of compartmental tests used in psychopharmacology. No toxicity was demonstrated at therapeutic doses. Each product had a sedative effect more or less pronounced and different from the reference substance clobazam (Urbanyl). They also had myorelaxant and anxiolytic effects, even lengthening the hypnotic effect of thiopental (synergic action).

Antiulcer activity of Pteleopsis suberosa

The bark Pteleopsis suberosa is commonly used in Mali for the treatment of gastric ulcers. The present study evaluated the antiulcerogenic property of chloroform, ethanol and aqueous extracts and of decoction of P. suberosa bark against ulcer lesions induced by ethanol and indomethacin in rats. The results tend to confirm the popular use of the plant.

Perceived morbidity and health behaviour in a Dogon community

The episodes of morbidity over a 6 month period were recorded at 179 households comprising 1715 people living in the district of Bandiagara (Mali). This population was subdivided into groups according to their distances from the nearest district health centre and educational services, their scholarization, socio-economic and hygiene levels. The subjects interviewed were asked to report illnesses using their vernacular names, the type of therapy selected, the decision process, the time-lapse between onset and remedial action, the treatment undergone and its effect. Subsequent analysis of the data recorded indicates that the frequency of morbidity episodes is inversely proportionate to the household's level of hygiene. It also appears that factors such as the household's hygienic, socio-economic and educational levels along with the type of illness and its duration, are more decisive when resorting (or not resorting) to treatment than is the proximity factor. This seems particularly true in the case of traditional medicine, chosen even where cosmopolitan resources are available and by people with a relatively high socio-economic, hygienic and educational level. In the specific situation under study this paper indicates those areas for further study with a view to improving public health education.

[Treatment of 700 cases of bilharziasis with the new drugs oxamniquine, oltipraz, praziquantel]

The authors study the results of a treatment of 700 cases of bilharziasis seen in Paris and in two foci in Togo, by oxamniquine, oltipraz or praziquantel. The three drugs are well tolerated; only a few mild side-effects were reported such as discomfort, nausea, headaches (two cases of acrodynia with oltipraz ). The three drugs are very efficacious in the case of schistosomiasis mansoni (85,5% success rate with oxamniquine, 92,9% with praziquantel, from 76,5 to 92% with oltipraz depending on the different strains) at day 180. As far as schistosomiasis haematobium is concerned, oltipraz and praziquantel have a 87,5% success rate with oltipraz and 80% with praziquantel; however, in the case of oltipraz , it is necessary to increase the dose. The action of praziquantel seems to be slower on Schistosoma haematobium than on S. mansoni. By the study of the evolution of antibodies, the fast action of praziquantel was noticed, explaining the peak of serological titers and of eosinophilia as early as day 10 after treatment; in the case of oltipraz , the apparition of this peak is only recorded at the 30th day. The slower effect of oltipraz on worms implicates not to judge its efficacy by too early controls.