Seasonal Microbial Conditions of Locally Made Yoghurt (Shalom) Marketed in Some Regions of Cameroon

The microbial conditions of locally made yoghurt (shalom) marketed in three areas of Cameroon were evaluated during the dry and rainy seasons alongside three commercial brands. A total of ninety-six samples were collected and the microbial conditions were based on total aerobic bacteria (TEB), coliforms, yeasts, and moulds counts as well as the identification of coliforms and yeasts using identification kits. Generally, there was a significant increase (p≤0.05) in total aerobic and coliform counts (especially samples from Bamenda), but a decrease in yeast and mould counts of the same samples during the rainy season when compared to those obtained during the dry season. These counts were mostly greater than the recommended standards. Twenty-one Enterobacteriaceae species belonging to 15 genera were identified from 72 bacterial isolates previously considered as all coliforms. Pantoea sp. (27.77%) was highly represented, found in 41% (dry season) and 50% (rainy season) of samples. In addition, sixteen yeast species belonging to 8 genera were equally identified from 55 yeast isolates and Candida sp. (76.36%) was the most represented. This result suggests that unhygienic practices during production, ignorance, warmer weather, duration of selling, and inadequate refrigeration are the principal causes of higher levels of contamination and unsafe yoghurts

Garcinia kola (Heckel) and Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. from Cameroon possess potential antisalmonellal and antioxidant properties.

Drug resistant Salmonella species and shortcomings related to current drugs stress the urgent need to search for new antimicrobial agents to control salmonellosis. This study investigated the antisalmonellal and antioxidant potentials of methanolic and hydro-ethanolic extracts of Garcinia kola and Alchornea cordifolia as potential sources of drugs to control Salmonella species and to reduce related oxidative stress. The antisalmonellal activity was assessed using the broth microdilution, membrane destabilization and time-kill kinetic assays. While, the DPPH, ABTS and FRAP assays were used for the determination of the antioxidant activities. The minimum inhibitory concentrations ranged from 125 to 1000 μg/mL, with the methanolic root extract of G. kola being the most active. The time kill kinetic assay revealed a concentration-dependent bacteriostatic activity for promising extracts. Potent extracts from G. kola showed the ability to destabilize S. typhi outer membrane, with the methanolic root extract presenting the highest activity; two-fold higher than those of polymyxin B tested as reference. In addition, this methanolic root extract of G. kola also provoked nucleotide leakage in a concentration-dependent manner. From the antioxidant assays, the hydro-ethanolic extract from the stem bark of A. cordifolia presented significant activities comparable to that of Vitamin C. The methanolic root extract of G. kola also presented appreciable antioxidant activities, though less than that of A. cordifolia. Overall, the phytochemical screening of active extracts revealed the presence of anthocyanins, flavonoids, glycosides, phenols, tannins, triterpenoids and steroids. These results provide evidence of the antibacterial potential of G. kola and offer great perspectives in a possible standardisation of an antisalmonellal phytomedicine

Potentiation effect of mallotojaponin B on chloramphenicol and mode of action of combinations against Methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus, the causative agent of many infectious diseases has developed resistance to many antibiotics, even chloramphenicol which was the essential antibiotic recommended for the treatment of bacterial infection. Thus, other alternatives to fight against S. aureus infections are necessary; and combinatory therapy of antibiotics with natural compounds is one of the approaches. This study evaluated the activity of the combination of mallotojaponin B and chloramphenicol against Methicillin-resistant Staphylococcus aureus (MRSA). Antibacterial activities were evaluated by broth microdilution and the checkerboard methods. Modes of action as time-kill kinetic, Nucleotide leakage, inhibition and eradication of biofilm, and loss of salt tolerance were evaluated. Cytotoxicity was evaluated on Vero and Raw cell lines. Mallotojaponin B showed good activity against MRSA with a MIC value of 12.5 μg/mL. MRSA showed high resistance to chloramphenicol (MIC = 250 μg/mL). The combination produced a synergistic effect with a mean FICI of 0.393. This combination was bactericidal, inducing nucleotide leakage, inhibiting biofilm formation, and eradicating biofilm formed by MRSA. The synergic combination was non-cytotoxic to Vero and Raw cell lines. Thus, the combination of mallotojaponin B and chloramphenicol could be a potential alternative to design a new drug against MRSA infections

In vitro and in vivo anti-salmonella properties of hydroethanolic extract of Detarium microcarpum Guill. & Perr. (Leguminosae) root bark and LC-MS-based phytochemical analysis.

Mbock MA, Fouatio WF, Kamkumo RG, et al. In vitro and in vivo anti-salmonella properties of hydroethanolic extract of Detarium microcarpum Guill. &amp; Perr. (Leguminosae) root bark and LC-MS-based phytochemical analysis. Journal of ethnopharmacology. 2020;260.ETHNOPHARMACOLOGICAL RELEVANCE: Typhoid fever treatment remains a challenge in endemic countries. Detarium microcarpum is traditionally used to manage typhoid.; AIM OF THE STUDY: The study aims to explore the efficacy of hydroethanolic extract of Detarium microcarpum root bark in rats infected with salmonella.; MATERIAL AND METHODS: The phytochemical profile of the extract was obtained by UHPLC-MS analysis in an attempt of standardization. The in vitro antimicrobial activity was determined using broth dilution method. Salmonella infection was induced by oral administration of S. thyphimurium to immunosuppressed rats. Infected rats were then treated 2 h later with the extract (75, 150 and 300 mg/kg), distilled water (normal and salmonella control) and ciprofloxacin (8 mg/kg) for control. Body weight was monitored and stools were cultured to determine the number of colony-forming units. At the end of treatment, animals were sacrificed, blood and organs were collected for hematological, biochemical and histopathological analyses.; RESULTS: Detarium microcarpum extract as well as the isolated compound (rhinocerotinoic acid) exhibited good antimicrobial activity in vitro with bacteriostatic effects. The plant extract significantly (p < 0.05) inhibited the bacterial development in infected animals with an effective dose (ED50) of 75 mg/kg. In addition, the extract prevented body weight loss, hematological, biochemical and histopathological damages in treated rats.; CONCLUSION: Detarium microcarpum extract possesses antisalmonella properties justifying its traditional use for the typhoid fever management. Copyright © 2020. Published by Elsevier B.V

Antifungal Properties of Chenopodium ambrosioides Essential Oil Against Candida Species

The essential oil of the aerial part (leaves, flowers and stem) of Chenopodium ambrosioides was obtained by hydrodistillation and its chemical composition analyzed by GC and GC/MS, which permitted the identification of 14 components, representing 98.8% of the total oil. Major components were α-terpinene (51.3%), p-cymene (23.4%) and p-mentha-1,8-diène (15.3%). The antifungal properties of this essential oil were investigated in vitro by the well diffusion and broth microdilution methods. The in vitro antifungal activity was concentration dependent and minimum inhibitory concentration values varied from 0.25 to 2 mg/mL. The in vivo antifungal activity was evaluated on an induced vaginal candidiasis rat model. The in vivo activity of the oil on mice vaginal candidiasis was not dose-dependent. Indeed, all the three tested doses; 0.1%, 1% and 10% led to the recovery of mice from the induced infection after 12 days of treatment. The effect of the essential oil on C. albicans ATCC 1663 fatty acid profile was studied. This oil has a relatively important dose-dependent effect on the fatty acids profile

Percentage of inhibition of synergistic combinations and chloramphenicol on Vero and Raw cells.

CPL: chloramphenicol; Comb: combination; Comb 1: 0.781 μg/mL of mallotojaponin B and 1.95 μg/mL of chloramphenicol; Comb 2: 0.781 μg/mL of mallotojaponin B and 7.812 μg/mL of chloramphenicol; Comb 3: 1.562 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol; Comb 4: 0.781 μg/mL of mallotojaponin B and 15.625 μg/mL of chloramphenicol; Comb 5: 0.781 μg/mL of mallotojaponin B and 31.25 μg/mL of chloramphenicol; Comb 6: 3.125 μg/mL of mallotojaponin B and 3.9 μg/mL of chloramphenicol; PODO: Podophyllotoxin; For the same cell lines, bars with the same letter show that there is no significant difference between the different treatments at p ≤0.05.</p

The diagonal lines for the interpretation of isobolograms in the interaction study between two bioactive substances.

A: Synergy, B: Additivity, C: Indifference, D: Antagonism.</p

Melokhanines A–J, Bioactive Monoterpenoid Indole Alkaloids with Diverse Skeletons from <i>Melodinus khasianus</i>

The new melokhanines A–J (<b>1</b>–<b>10</b>) and 22 known (<b>11</b>–<b>32</b>) alkaloids were isolated from the twigs and leaves of <i>Melodinus khasianus</i>. The new compounds and their absolute configurations were elucidated by extensive analysis of spectroscopic, X-ray diffraction, and computational data. Melokhanine A (<b>1</b>), composed of a hydroxyindolinone linked to an octahydrofuro­[2,3-<i>b</i>]­pyridine moiety, is an unprecedented monoterpenoid indole alkaloid. Melokhanines B–H (<b>2</b>–<b>8</b>) possess a new 6/5/5/6/6 pentacyclic indole alkaloid skeleton. Alkaloids <b>1</b>–<b>16</b>, <b>25</b>–<b>27</b>, <b>31</b>, and <b>32</b> showed the best antibacterial activity against <i>Pseudomonas aeruginosa</i> (MIC range 2–22 μM). Among the seven dermatophytes tested, compound <b>1</b> showed significant inhibitory activity against <i>Microsporum canis</i>, <i>M. ferrugineum</i>, and <i>Trichophyton ajelloi</i> (MIC range 38–150 μM), i.e., half the efficacy of the positive control, griseofulvin