Dieudonné Adiogo

Extended-spectrum-beta-lactamase-producing Enterobacteriaceae in Yaounde, Cameroon

ABSTRACT Organisms producing extended-spectrum β-lactamases (ESBLs) have been reported in many countries, but there is no information on the prevalence of ESBL-producing members of the family Enterobacteriaceae in Cameroon. A total of 259 Enterobacteriaceae strains were isolated between 1995 and 1998 from patients at the Yaounde Central Hospital in Cameroon. Enterobacterial isolates resistant to extended-spectrum cephalosporin and monobactam were screened for ESBL production by the double-disk (DD) synergy test. Thirty-one (12%) of these Enterobacteriaceae strains were shown to be positive by the DD synergy test, suggesting the presence of ESBLs. Resistance to oxyimino-cephalosporins and monobactams of 12 (38.7%) of the 31 strains—i.e., 6 Klebsiella pneumoniae, 4 Escherichia coli, 1 Citrobacter freundii, and 1 Enterobacter cloacae strain—was transferred to E. coli HK-225 by conjugation. Resistance to gentamicin, gentamicin plus trimethoprim-sulfamethoxazole, or trimethoprim-sulfamethoxazole was cotransferred into 6, 2, and 1 of these transconjugants, respectively. All 12 transconjugants were resistant to amoxicillin, piperacillin, all of the cephalosporins, and aztreonam but remained susceptible to cefoxitin and imipenem. Crude extracts of β-lactamase-producing transconjugants were able to reduce the diameters of inhibition zones around disks containing penicillins, narrow- to expanded-spectrum cephalosporins or monobactams when tested against a fully susceptible E. coli strain but had no effect on such zones around cefoxitin, imipenem, and amoxicillin-clavulanate disks. The β-lactamases produced by the 12 tranconjugants turned out to be SHV-12 by DNA sequencing. Therefore, the ESBL SHV-12 is described for the first time in Cameroon.

Ceramide, cerebroside and triterpenoid saponin from the bark of aerial roots of Ficus elastica (Moraceae).

Three compounds, ficusamide (1), ficusoside (2) and elasticoside (3), were isolated from the bark of aerial roots of Ficus elastica (Moraceae), together with nine known compounds, including four triterpenes, three steroids and two aliphatic linear alcohols. The chemical structures of the three compounds were established by extensive 1D and 2D NMR spectroscopy, mass spectrometry and by comparison with published data. The growth inhibitory effect of the crude extract and isolated compounds was evaluated against several microorganisms and fungi. The cytotoxicity against human cancer cell lines was also assessed. Ficusamide (1) displayed a moderate in vitro growth inhibitory activity against the human A549 lung cancer cell line and a strong activity against Staphylococcus saprophyticus, while elasticoside (3) showed a potent activity on Enterococcus faecalis.

SHARED G12 VP7 GENE AMONG HUMAN AND BOVINE ROTAVIRUSES DETECTED IN CAMEROONIAN VILLAGES

Group A rotaviruses (RVA) are an important enteric pathogen in humans and livestock animals. Transmission of animal RVA strains to humans has been documented on several occasions. A reverse route of transmission of RVA under natural circumstances is anticipated, although evidence is scarce. However, experimental studies indicated that animals can be infected with human RVAs. By screening the stool samples collected from 157 cattle during 2011 in two Cameroonian villages, four samples (2.5%) were found positive for RVA. Upon sequence analysis of a 410 bp fragment of the VP7 gene, the RVA strains shared up to 100% nt identity to each other and to G12 RVAs identified in human patients living in the same geographic regions. This finding provides evidence for a human-to-animal transmission of an epidemic human rotavirus strain.

In vitro antimicrobial and anti-proliferative activities of plant extracts from Spathodea campanulata, Ficus bubu, and Carica papaya

Abstract Context African medicinal plants represent a prominent source of new active substances. In this context, three plants were selected for biological investigations based on their traditional uses. Objective The antimicrobial and anti-proliferative features of three plants used for medicinal purpose were evaluated. Materials and methods The antimicrobial activities of methanol extracts of Ficus bubu Warb. (Moraceae) stem bark and leaves, of Spathodea campanulata P. Beauv. (Bignoniaceae) flowers, as well as those of Carica papaya Linn. (Caricaceae) latex, were determined using the microbroth dilution method against a set of bacteria and fungi pathogens including: Enterococcus faecalis, Staphylococcus aureus, S. saprophyticus, S. epidermididis, Escherichia coli, Klebsiella pneumonia, Salmonella typhimurium, Candida albicans, and Trichophyton rubrum. The tested concentrations of extracts ranged from 2500.0 to 2.4 μg/mL and MIC values were evaluated after 24 h incubation at 37 °C. Subsequently, MTT assay was used to estimate anti-proliferative activity of these methanol extracts and of F. bubu latex on three human cancer cell lines (U373 glioblastoma, A549 NSCLC, and SKMEL-28 melanoma). Results The methanol extract of F. bubu stem bark exhibited the highest antimicrobial activity against C. albicans with a MIC value of 9.8 μg/mL, while the F. bubu latex and the methanol extract of F. bubu leaves induced significant anti-proliferative activity against lung (IC50 values of 10 and 14 μg/mL, respectively) and glioma (IC50 values of 13 and 16 μg/mL, respectively) cancer cells. Conclusion These results indicate that effective drugs could be derived from the three studied plants.

Variations de la concentration du facteur Von Willebrand au cours de la grossesse

The multimeric glycoprotein Von Willebrand factor (vWF), is produced by vascular endothelium and platelet. If some constitutionals deficiencies leading to hemorrhagic syndrome have been explored in the literature, increased production of vWF observed during cellular distress and pregnancy have not been explored in our milieu. The aim of this study was to determine vWF changes during pregnancy in a group of Cameroonian women and find out the possibility of using it as a marker of fetal distress. Serum was collected from 46 women in the second and third trimesters of pregnancy. The determination of vWF concentration was performed using the Asserachrom vWF reagent: Ag (Diagnostica Stago, France). The average concentrations of vWF in the second and third trimester samples were respectively 215.47 ± 9.38% (UI/dL) and 264.09 ± 11.58% (UI/dL). The difference between (i) concentrations of vWF during the second and third trimester of pregnancy was statistically significant (P-value<0.0001); (ii) concentrations of vWF according to mothers ages was not significant; (iii) concentrations of vWF in blood group O and B women was statistically significant (P-value<0.05). We observed a difference between vWF values in women whose babies had Apgar score 4 to 6 compared to those with Apgar score between 7 and 10. The different was not statistically significant probably due to low effective. In conclusion, vWF production during the pregnancy varies with gestational age and maternal blood group. It may increases during fetal distress.

Phenotypic Detection of Extended Spectrum β-Lactamase and AmpC producing Enterobacteriaceae Isolated in A General Hospital

Objective: The antibiotic resistance of Enterobacteriaceae is a worldwide preoccupation, and misuse antibiotics of beta-lactam group allowed the development of bacteria producing extended spectrum beta-lactamase and cephalosporinase AmpC enzymes type resistance. The aim of this study was to determine the frequency of these enzymes among strains isolated at the General Hospital in Douala, Cameroon. Methods: We conducted a cross-sectional study. For phenotypic detection of resistance enzymes, MASTDISCS™ test impregnated third and fourth generation cephalosporin’s was used by diffusion on Mueller Hinton agar. Measuring the inhibition areas and comparing the inhibition diameters determined the nature of the resistance mechanism. Results: This study included 195 strains of Enterobacteriaceae . The most frequent species were Escherichia coli and Klebsiella pneumoniae , with a frequency of 49.2% and 31.3% respectively. After determination of resistance phenotypes, 101 (51.8%) isolates were found to be producing resistance enzymes. The frequency of ESBL-producing Enterobacteriaceae was 19.5%; AmpC producing was 14.3% and both enzymes (AmpC + ESBL) 17.9%. E. coli and K. pneumoniae resistance rates were 90% and 83.7% for Cotrimoxazole, 82.5% and 78.3% for ciprofloxacin, 20% and 13.5% for Amikacin, respectively. Imipenem, Amikacin and Fosfomycin were the most active molecules with 4.9%, 19.8% and 33.6%, out of 101 resistant strains, respectively. Conclusion: This study showed a high frequency of resistance enzyme producing strains. This situation leads to resistance to antibiotics most commonly used. This finding justifies a change in prescription habits for protection of molecules that are still active. J Microbiol Infect Dis 2018; 8(3):113-119

Seroprevalence, attitudes and practices of the Baka Pygmies of eastern Cameroon towards HIV and AIDS.

INTRODUCTION The vulnerable health status of Pygmies is the result of their continual exposure to the modern world. The purpose of this study was to determine the prevalence of HIV and the attitudes and practices of Baka populations towards HIV infection. METHODOLOGY A descriptive and cross-sectional study was conducted over a five-month period in 12 Pygmy camps. A questionnaire was completed to collect information, and anonymous screenings were held. For screening, whole blood was collected. The Determine HIV-1/2 test was used as the rapid test, and the SD Bioline HIV-1/2 test was used as the second test. Associations between variables were checked. RESULTS A total of 560 Baka were recruited. The sex ratio was 0.92. Among the means of transmission, sexual intercourse was the most frequently cited (37.6%). A minority (28.5%) knew where to undergo an HIV test, 24.2% did not know that there exists treatment enabling patients to have a higher quality of life, and 75.7% had never used a condom. A total of 86.9% had never been tested for HIV. Subjects who had sex with the Bantu were three times more likely to be infected (p = 0.02), as well as those who had had more than three sexual partners. CONCLUSIONS The changes affecting contemporary societies are inevitably influenced by the dominant factors of modernity, particularly progress, development, and social dynamics in all their aspects. Baka knowledge about HIV/AIDS is limited. Educational efforts, increased awareness, and guidance are needed.

Profil clinique et immunologique des patients infectés par le VIH à l’initiation du traitement antirétroviral à Douala

The aim of this study was to describe the clinical and immunological profile of patients infected with HIV after initiation of antiretroviral therapy. Sociodemographic characteristics, clinical and immunological patients were recorded. Chi square test and Mann-Whitney were used to compare variables. The multivariate regression model identified risk factors. So that, 936 (56.2%) patients were in stages III and IV of the WHO and 65.2% at an advanced stage of the disease. Factors associated with initiation at an advanced stage, were male sex (p = 0.007) and time to diagnosis (p = 0.005). In 2/3 cases, treatment is started at an advanced stage of disease. It is therefore important to intensify awareness campaigns for early detection and encourage patients to ensure regular medical follow-up screening.

Profil clinique et immunologique des patients infectés par le VIH à l’initiation du traitement antirétroviral à Douala@@@Clinical and immunological profile of HIV-infected patients at the initiation of antiretroviral therapy in Douala

The aim of this study was to describe the clinical and immunological profile of patients infected with HIV after initiation of antiretroviral therapy. Sociodemographic characteristics, clinical and immunological patients were recorded. Chi square test and Mann-Whitney were used to compare variables. The multivariate regression model identified risk factors. So that, 936 (56.2%) patients were in stages III and IV of the WHO and 65.2% at an advanced stage of the disease. Factors associated with initiation at an advanced stage, were male sex (p = 0.007) and time to diagnosis (p = 0.005). In 2/3 cases, treatment is started at an advanced stage of disease. It is therefore important to intensify awareness campaigns for early detection and encourage patients to ensure regular medical follow-up screening.