Chemical constituents of Palisota ambigua (Commelinaceae) with their antibacterial activities

-Simionne Lapoupée Kuitcha Tonga; Benjamin Tangue Talom; Germaine Matsuete Takongmo; Bienvenu Tsakem; Beaudelaire Kemvoufo Ponou; Léon Azefack Tapondjou; Jean-De-Dieu Tamokou; Rémy Bertrand Teponno.

Background: The development and spread of resistance by bacteria to existing antibiotics are becoming more common nowadays. Considering the ethnopharmacological relevance of Palisota ambigua (Commelinaceae), this study was designed to investigate the antibacterial activities of chemical constituents of P. ambigua against two Gram-positive (Staphylococcus aureus ATCC 25923 and Streptococcus pneumoniae ATCC 49619) and two Gram-negative (Escherichia coli ATCC 8739 and Klebsiella pneumoniae 109 (iso...

Antibacterial activity of phytochemicals from Bauhinia thonningii significantly increased in the presence of the efflux pump inhibitor, phenylalanine-arginine-β-naphthylamide towards multidrug-resistant phenotypes

-Valaire Y. Matieta; Guy R. Sado Nouemsi; Aimé G. Fankam; Jenifer R. N. Kuete; Fabrice J. Megaptche; Alain M. Lannang; İlhami Çelik; Armelle T. Mbaveng; Victor Kuete.

Abstract Background: View the rapid spread of multidrug-resistant bacteria worldwide; alternatives to antibiotics are necessary for handling various bacterial infections. This study aimed to investigate the antibacterial activity of eight flavonoids isolated from the leaves methanol extract of Bauhinia thonningii against multi-drug resistant (MDR) bacteria expressing efflux pumps. Methods: The antibacterial activity of the phytochemicals alone and in the presence of phenylalanine-arginine...

Effect of combination of doxycycline with natural products against planktonic cells, biofilm, and virulence factor of Pseudomonas aeruginosa

-Larissa Yetendje Chimi; Armel Joseph Agokeng; Guy Sedar Singor Njateng; Jean Paul Dzoyem

Abstract Background: Pseudomonas aeruginosa is an important environmental, opportunistic, and nosocomial pathogen with a significant threat to public health. Combination therapy has many advantages due to the simultaneous action of two drugs on two separate cellular targets. In the present study, the effect of the combination of doxycycline and natural products against planktonic cells, biofilm, and virulence factors of P. aeruginosa was evaluated. Methods: To perform this work, minimal i...

A moderately active crude methanol extract from the whole plant of Kalanchoe crenata (Andrews) Haw. (Crassulaceae) strongly potentiated the effect of antibiotics against multidrug-resistant Gram-negative bacteria

-Fabrice W. Fokou; Ramelle Ngakam; Valaire Y. Matieta; Gaelle Kengne Fonkou; Stephanie Mapie Tiwa; Junior F. Megaptche; Paul Nayim; Véronique P. Beng; Armelle T. Mbaveng; and Victor Kuete.

Abstract Background: Resistant bacteria develop a high level of resistance to multiple drugs, limiting treatment options and increasing morbidity and mortality. This work was planned to evaluate the antibacterial potential of the methanol extract from the whole plant of Kalanchoe crenata (KCW) against multidrug-resistant (MDR) Gram-negative bacteria. Methods: The minimal inhibitory concentrations (MIC) and the minimal bactericidal concentrations (MBC) of KCW alone, in the presence of an e...

Botanical from the bark of Zizyphus jujuba Mill. (Rhamnaceae) had weak anti-Klebsiella activity, but strongly potentiated the effects of antibiotics against multidrug-resistant phenotypes

-Gaelle Kengne Fonkou; Garandi Badawe; Valaire Y. Matieta; Stephanie Mapie Tiwa; Ramelle Ngakam; Junior F. Megaptche; Paul Nayim; Victor Kuete; and Armelle T. Mbaveng.

Abstract Background: Klebsiella pneumoniae is medically the most important species of this genus. Klebsiella oxytoca also cause infections in human but to a much lesser degree than K. pneumoniae. In this work, the antibacterial potential of the methanol extract from the bark of Zizyphus jujuba (ZJB) was evaluated against the multidrug-resistant (MDR) clinical isolates of Klebsiella pneumoniae and Klebsiella oxytoca overexpressing AcrAB-TolC efflux pumps. Methods: The broth microdilution m...

Botanicals from Aframomum letestuanum Gagnep. (Zingiberaceae) can overcome the multidrug resistance of Klebsiella species overexpressing AcrAB-TolC efflux pumps

-Gaelle Kengne Fonkou; Valaire Y. Matieta; Stephanie Mapie Tiwa; Ramelle Ngakam; Junior F. Megaptche; Paul Nayim; Victor Kuete; Armelle T. Mbaveng.

Abstract Background: Bacteria belonging to the genus Klebsiella have developed resistance mechanisms to clinically used antibiotics, leading to their loss of efficacy. In the present study, the in vitro antibacterial activity of methanol extracts from Aframomum letestuanum, as well as their modes of action against a panel of 14 bacterial species belonging to the genus Klebsiella including multidrug-resistant (MDR) phenotypes overexpressing efflux pumps were evaluated. Methods: The broth m...

Antibacterial potential and modes of action of methanol extracts of flowers and leaves of Vernonia glabra (Steetz) Vatke (Asteraceae) against multidrug-resistant Gram-negative bacteria overexpressing efflux pumps

-Ramelle Ngakam; Valaire Y. Matieta; Gaelle Kengne Fonkou; Stephanie Mapie Tiwa; Junior F. Megaptche; Paul Nayim; Armelle T. Mbaveng; Victor Kuete

Abstract Background: Bacterial infections caused by multidrug-resistant (MDR) Gram-negative bacteria remain a public health problem and have contributed to a reduction in the range of antibiotics available for antibiotic therapy. The search for new antibacterial substances is becoming increasingly important, and plants represent an important reservoir of therapeutic molecules. In the present study, the antibacterial activity, and modes of action of Vernonia glabra against Gram-negative and m...

Antibacterial potential and modes of action of the methanol extracts of Elephantopus mollis Kunth (Asteraceae) against multidrug-resistant Gram-negative bacteria overexpressing efflux pumps

-Stephanie Mapie Tiwa; Valaire Y. Matieta; Ramelle Ngakam; Gaelle Kengne Fonkou; Junior F. Megaptche; Paul Nayim; Armelle T. Mbaveng; Victor Kuete.

Abstract Background: Bacterial drug resistance still constitutes a major clinical issue. In the present study, the in vitro antibacterial potential, and modes of action of Elephantopus mollis were investigated. Methods: The antibacterial activity of methanol extracts of the various parts of E. mollis, their association with an efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN), and the potentiating effect of several standard antibiotics were determined using the broth mi...