Novel Aeromonas Phage Ahy-Yong1 and Its Protective Effects against Aeromonas hydrophila in Brocade Carp (Cyprinus aka Koi)

Abstract

Aeromonas hydrophila is a zoonotic pathogen and an important fish pathogen. A new lytic phage, Ahy-yong1, against multi-antibiotic-resistant pathogen A. hydrophila was isolated, identified, and tentatively used in therapy. Ahy-yong1 possesses a head of approximately 66 nm in diameter and a short tail of approximately 26 nm in length and 32 nm in width. Its complete dsDNA genome is 43,374 bp with a G + C content of 59.4%, containing 52 predicted opening reading frames (ORFs). Taxonomic analysis indicated Ahy-yong1 as a new species of the Ahphunavirus genus of the Autographiviridae family of the Caudoviricetes class. Ahy-yong1 was active only against its indicator host strain among the 35 strains tested. It is stable at 30–40 °C and at pH 2–12. Aeromonas phage Ahy-yong1 revealed an effective biofilm removal capacity and an obvious protective effect in brocade carp (Cyprinus aka Koi). The average cumulative mortality for the brocade carp in the blank groups intraperitoneally injected with PBS was 1.7% ± 2.4%;for the control groups treated with A. hydrophila (108 CFU/fish) via intraperitoneal injection, it was 100.00%;and for the test group I, successively treated with A. hydrophila (108 CFU/fish) and Aeromonas phage Ahy-yong1 (107 PFU/fish) via intraperitoneal injection witha time interval of 2 hours, it was only 43.4% ± 4.7%. Furthermore, the cumulative mortality of the test group II, successively treated with Aeromonas phage Ahy-yong1 (107 PFU/fish) and A. hydrophila (108 CFU/fish), was only 20.0% ± 8.2%, and that of the test group III, simultaneously treated with Aeromonas phage Ahy-yong1 (107 PFU/fish) and A. hydrophila (108 CFU/fish), was only 30.0% ± 8.2%. The results demonstrated that phage Ahy-yong1 was very effective in the therapies against A. hydrophila A18, prophylaxis was more effective than rescue, and earlier treatment was better for the reduction of mortality. This study enriches knowledge about Aeromonas phages.

Isolation and characterization of the lytic Aeromonas phage HJ05,a new member of Caudovirales

“…and 75 •C, respectively. To evaluate pH stability of HJ05, aliquots of 1 mL stocked solution (10 8 PFU/mL) was treated at 30 •C for 2 h with 10 mL PBS buffers with varied pH values (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). The experiments were performed according to a previos report [38], and the tests were conducted in triplicate.…”

“…Phagebased biocontrol strategies have been regarded as a promising and environmentally friendly alternative to antibiotics for the treatment of A. hydrophila infection. Recently, various phages have been identi ed and characterized to test their potential against A. hydrophila infection, which at least include Autographiviridae phage Ahy-yong1 [12], Podoviridae phage vB_ AhaP_PZL-Ah8 [13], Caudovirales phage AhMtk13a [14], Podoviridae phage ZPAH7 [15], Caudovirales phage AHP-1[16], Podoviridae phage MJG [17], Caudovirales phage CC2[18], Caudovirales phage PVN02 [19], Caudovirales phage Ahp2 [20], Podoviridae phage PZL-Ah152 [21], Podoviridae phages PZL-Ah1 and PZL-Ah8 [22], Caudovirales phage phiA8-29 [23], Caudovirales phage AhyVDH1 [24], Caudovirales phage vB-AhyM-AP1 [25], Caudovirales phages N21, W3 and G65[26], Podoviridae phages Y71 and Y81[26], Chaseviridae phage pAh6.2TG [27], Siphoviridae phage Akh-2[28], Caudovirales phage VTCCBPA6 [29], Caudovirales phages CF8, PS1, and PS2 [30]. Siphoviridae phages AhSzq-1 and AhSzw-1 [31].…”

“…Phages generally act as a role of predator in the microbial ecosystem, while bacteria can readily evolve phage resistance, making it crucial for isolating and characterizing more potential phages in phage therapy [32]. Most Aeromonas phages display narrow host speci city, which can be disadvantageous in phage therapy using a single phage [12]. Indeed in vitro and in vivo studies have shown the importance of using phage cocktails rather than single phage preparations to achieve better therapy outcomes [33].…”

Phage Delivery Strategies for Biocontrolling Human, Animal, and Plant Bacterial Infections: State of the Art

“…There is much research examining the efficacy of using phages as antibacterials, specifically in food-animal production, aiming to control bacterial diseases [ 22 ]. Particularly, phages have been studied for controlling bacterial diseases in poultry [ 7 , 11 , 23 , 24 ], pigs [ 22 ], calves [ 25 ], and fish [ 26 ]. Zoonotic pathogens associated with poultry and pigs, such as Salmonella spp., E .…”

Characterization of vB_ValM_PVA8, a broad-host-range bacteriophage infecting Vibrio alginolyticus and Vibrio parahaemolyticus

“…Similarly, phage therapy has great potential in aquaculture against pathogenic bacteria (Le and Kurtböke, 2019;Le et al, 2018). Recently, many successful cases of phage therapy for preventive and therapeutic purposes in aquaculture have been reported, using phages targeting Vibrio species including V. parahaemolyticus (Wong et al, 2019;Tan et al, 2021), V. alginolyticus (Li et al, 2019;Chen et al, 2020), Vibrio harveyi (Misol et al, 2020;Wu et al, 2021), Vibrio vulnificus (Kim et al, 2021), Vibrio anguillarum (Mauritzen et al, 2020), Vibrio campbellii (Lomeli-Ortega et al, 2021), Vibrio mediterranean (Xu et al, 2021) and other species including Pseudomonas aeruginosa (Cafora et al, 2019), Aeromonas hydrophila (Le et al, 2018;Pan et al, 2022;SumeetRai et al, 2023), and Flavobacterium columnare and other fish pathogens.…”