Antibiotic resistance in Helicobacter pylori is a factor preventing its successful eradication. Particularly in developing countries, resistance against commonly used antibiotics is widespread. Here, we present an epidemiological study from Nigeria with 111 isolates. We analyzed the associated disease outcome, and performed a detailed characterization of these isolated strains with respect to their antibiotic susceptibility and their virulence characteristics. Furthermore, statistical analysis was performed on microbiological data as well as patient information and the results of the gastroenterological examination. We found that the variability concerning the production of virulence factors between strains was minimal, with 96.4% of isolates being CagA-positive and 92.8% producing detectable VacA levels. In addition, high frequency of bacterial resistance was observed for metronidazole (99.1%), followed by amoxicillin (33.3%), clarithromycin (14.4%) and tetracycline (4.5%). In conclusion, this study indicated that the infection rate of H. pylori infection within the cohort in the present study was surprisingly low (36.6%). Furthermore, an average gastric pathology was observed by histological grading and bacterial isolates showed a uniform pathogenicity profile while indicating divergent antibiotic resistance rates.

Thirty-two actinomycetes strains were isolated from sediment samples from 12 different sites at Lagos Lagoon and identified using standard physiological and biochemical procedures as well as 16S rDNA gene sequence analysis. Secondary metabolites were extracted from the strains and their anticancer activity on the K562 (Human acute myelocytic leukemia), HeLa (cervical carcinoma), AGS (Human gastric), MCF-7 (breast adenocarcinoma) and HL-60 (Human acute promyelocytic leukemia) cell lines was determined. The metabolic extracts exhibited cytotoxicity with IC 50 values ranging from 0.030 mg/mL to 4.4 mg/mL. The Streptomyces bingchenggensis ULS14 extract was cytotoxic against all the cell lines tested. The bioactivity-guided extraction and purification of the metabolic extracts from this strain yielded two purified anticancer compounds: ULDF4 and ULDF5. The structures of the extracted compounds were determined using spectroscopic analyses, including electrospray ionization mass spectrophotometer and nuclear magnetic resonance (1 Dimensional and 2 Dimensional), and were shown to be structurally similar to staurosporine and kigamicin. The IC 50 of ULDF4 and ULDF5 against the HeLa cell line was 0.034 μg/mL and 0.075 μg/mL, respectively. This study is the first to reveal the anticancer potential of actinomycetes from Lagos Lagoon, which could be exploited for therapeutic purposes.

The antimicrobial activity of extracts of twelve Nigerian medicinal plant species and a "wonder cure" concoction [Epa-Ijebu]; used in traditional medicine for the treatment of tuberculosis and cough were screened for activity against Mycobacterium tuberculosis isolated from tuberculosis patient sputum and the control strains of M. tuberculosis (H37RV). Both ethanolic and aqueous solution of the extract of Allium ascalonicum, Terminalia glaucescens, Allium cepa and Securidaca longepedunculata (ethanolic extract only) at 0.05g/ml as well as aqueous solution of "wonder cure" concoction at same concentration inhibited the growth of M. tuberculosis. However at lower concentration of 0.2 µg/ml (critical proportion level of the control drug (isoniazide), M. tuberculosis was resistant to both aqueous and ethanolic extracts of the plants as well as the aqueous solution of the wonder-cure concoction. The phytochemical analysis of the plant extract and the Epa-Ijebu showed the presence of bioactive compounds: tannin, flavonoid, alkaloids, phlobatannin, anthocyanin, reducing sugar, saponin and anthraquinone. Our results offer a scientific basis for the traditional use of aqueous and ethanolic extracts of Allium ascalonicum, Terminalia glaucescens, Allium cepa, Securidaca longepeducunlata (ethanolic extract only) and aqueous solution of the "wonder cure" concoction at higher concentration against M. tuberculosis. However local herbs such as Nicotiana tabacum, Allium sativum, Aframomum melegueta, Aprus precatorius, Xylopia aethiopica, Tetrapleura tetraptera, Crinium jagus, and Garcinia kola were ineffective.

Helicobacter pylori is a gram-negative, spiral-shaped bacterial pathogen and the causative agent for gastritis, peptic ulcer disease and classified as a WHO class I carcinogen. While the prevalence of H. pylori infections in Africa is among the highest in the world, the incidence of gastric cancer is comparably low. Little is known about other symptoms related to the H. pylori infection in Africa and the association with certain phenotypes of bacterial virulence. We established a network of study sites in Nigeria (NG) and South Africa (ZA) to gain an overview on the epidemiological situation. In total 220 isolates from 114 patients were analyzed and 118 different patient isolates examined for the presence of the virulence factors cagA, vacA, dupA , their phylogenetic origin and their resistance against the commonly used antibiotics amoxicillin, clarithromycin, metronidazole and tetracycline. We report that H. pylori isolates from Nigeria and South Africa differ significantly in their phylogenetic profiles and in their expression of virulence factors. VacA mosaicism is intensive, resulting in m1-m2 vacA chimeras and frequent s1m1 and s1m2 vacA subtypes in hpAfrica2 strains. Gastric lesions were diagnosed more frequent in Nigerian versus South African patients and H. pylori isolates that are resistant against one or multiple antibiotics occur frequently in both countries.

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