Extracts of Hesperozygis ringens (Benth.) Epling: in vitro and in vivo antibacterial activity against fish pathogenic bacteria

Abstract

Aims This study investigated the in vitro antibacterial activity of Hesperozygis ringens (Benth.) Epling leaf extracts against fish pathogenic bacteria, as well as the in vivo activity of the most active extract in silver catfish (Rhamdia quelen) experimentally infected with Aeromonas hydrophila. Moreover, the chemical composition of the extract used in the survival assay was evaluated. Methods and Results Only hexane extract (HEHR) showed in vitro antibacterial activity (MIC and MBC ranging from 1600 to 3200 μg ml−1) against clinical isolates of A. hydrophila, Raoultella ornithinolytica and Citrobacter freundii, obtained from naturally infected silver catfish, and A. hydrophilaATCC 7966. The major compound of the volatile fraction of HEHR was determined as pulegone. HEHR promoted a 93·33% relative survival rate of silver catfish experimentally infected with A. hydrophila 7 days after a single therapeutic bath at 30 mg l−1, while florfenicol at 4 mg l−1, which promoted a 60% relative survival rate. Conclusions The antibacterial activity of H. ringens (Benth.) Epling leaf extracts seems to be related to phytochemicals of apolar character, since HEHR promoted better survival rate of infected animals than florfenicol. Significance and Impact of the Study The HEHR has potential to be used in the control and treatment of bacterial infections in organic aquaculture.

Natural Sunlight-Mediated Emodin Photoinactivation of Aeromonas hydrophila

“…For example, resveratrol [22,23], thymol [24], fraxetin [25], oridonin [26], magnolol [27], baicalin [28], and emodin [29] from traditional Chinese herbs display an inhibitory activity against A. hydrophila. In addition, extracts from Ficus leaves [30], Moringa oleifera leaves [31], the Araucaria angustifolia [32] seed coat, and Hesperozygis ringens [33] also have the ability to inhibit the growth of A. hydrophila. Furthermore, extracts such as essential oils (e.g., clove [34], rosemary [35], and cinnamon [36]) exhibit the activity of inhibiting A. hydrophila.…”

Mitigating Aeromonas hydrophila infection in Nile tilapia through dietary Basella alba and Withania somnifera supplementation: A bioassay‐guided fractionation approach

“…Antibacterial activity of plant material may be contingent on the presence of extractable active compounds, which is dependent on the property and polarity of extracting solvent (Onyebuchi & Kavaz, 2020). Variable antimicrobial efficacy against A. hydrophila was earlier observed for different solvent extracts of Hesperozygis ringens (Rosa et al, 2019). In the pres- extracts rich in phenolic compounds were postulated to destroy bacterial cell membranes and show antimicrobial activity (Monir et al, 2020).…”

Identification and characterization of a novel 6′-N-aminoglycoside acetyltransferase AAC(6′)-Va from a clinical isolate of Aeromonas hydrophila

“…Pathogenic bacteria play a significant role in the occurrence of common fish diseases in aquaculture (Rosa et al, 2019). Among the identified bacterial pathogens, A. hydrophila is widely recognized as a major pathogen affecting various aquatic animal species and has been responsible for significant economic losses in recent years (Saraceni et al, 2016;Pengcheng et al, 2017).…”