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Islam SI, Shahed K, Ahamed MI, Khang LTP, Jung WK, Sangsawad P, Dinh-Hung N, Permpoonpattana P, Linh NV. Pathogenomic Insights into Piscirickettsia salmonis with a Focus on Virulence Factors, Single-Nucleotide Polymorphism Identification, and Resistance Dynamics. Animals (Basel) 2025; 15:1176. [PMID: 40282010 PMCID: PMC12024244 DOI: 10.3390/ani15081176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2025] [Revised: 04/11/2025] [Accepted: 04/18/2025] [Indexed: 04/29/2025] Open
Abstract
Effective control of bacterial infections remains a significant challenge in aquaculture. The marine bacterium Piscirickettsia salmonis (P. salmonis), responsible for piscirickettsiosis, causes widespread infections in various salmon species, leading to substantial mortality and economic losses. Despite efforts to genetically characterize P. salmonis, critical gaps persist in understanding its virulence factors, antimicrobial resistance genes, and single-nucleotide polymorphisms (SNPs). This study addresses these gaps through a comparative analysis of the pan-genome and core genomes of 80 P. salmonis strains from different geographical regions and genogroups. P. salmonis had an open pan-genome consisting of 14,564 genes, with a core genome of 1257 conserved genes. Eleven virulence-related genes were identified in the pan-genome, categorized into five functional groups, providing new insights into the pathogenicity of P. salmonis. Unique SNPs were detected in four key genes (gyrA, dnaK, rpoB, and ftsZ), serving as robust molecular markers for distinguishing the LF and EM genogroups. Notably, AMR genes identified in four LF strains suggest evolutionary adaptations under selective pressure. Functional annotation of the core genomes using the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases demonstrated conserved gene clusters linked to essential intracellular survival mechanisms and bacterial pathogenicity. These findings suggest a direct association between core genome features and variations in pathogenesis and host-pathogen interactions across genogroups. Phylogenetic reconstruction further highlighted the influence of AMR genes on strain divergence. Collectively, this study enhances the genomic understanding of P. salmonis and lays the groundwork for improved diagnostic tools and targeted therapeutics to manage piscirickettsiosis in aquaculture.
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Affiliation(s)
| | - Khandker Shahed
- BioMac Lab, Dhaka 1217, Bangladesh; (S.I.I.); (K.S.); (M.I.A.)
| | | | - Luu Tang Phuc Khang
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Won-Kyo Jung
- Major of Biomedical Engineering, Division of Smart Healthcare, College of Information Technology and Convergence and New-Senior Healthcare Innovation Center (BK21 Plus), Pukyong National University, Busan 48513, Republic of Korea;
| | - Papungkorn Sangsawad
- School of Animal Technology and Innovation, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand;
| | - Nguyen Dinh-Hung
- Aquaculture Pathology Laboratory, School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ 85721, USA;
| | - Patima Permpoonpattana
- Department of Agricultural Science and Technology, Faculty of Innovative Agriculture, Fisheries and Food, Prince of Songkla University, Surat Thani Campus, Surat Thani 84000, Thailand
| | - Nguyen Vu Linh
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand;
- Functional Feed Innovation Center (FuncFeed), Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
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Abo-Shama UH, El Raheem AAA, Alsaadawy RM, Sayed HH. Phenotypic and genotypic characterization of Aeromonas hydrophila isolated from freshwater fishes at Middle Upper Egypt. Sci Rep 2025; 15:5920. [PMID: 39966501 PMCID: PMC11836066 DOI: 10.1038/s41598-025-89465-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2024] [Accepted: 02/05/2025] [Indexed: 02/20/2025] Open
Abstract
Aeromonas hydrophila is a common fish pathogen and a significant foodborne pathogen of increasing public health concern. This study was conducted in Middle Upper Egypt to determine the prevalence of A. hydrophila among the diseased Oreochromis niloticus (n = 100) and Clarias gariepinus (n = 100) at Assiut and Sohag Governorates. A. hydrophila isolates (n = 44) were assessed for antimicrobial susceptibility and biofilm production. Moreover, PCR was performed to analyze the incidence of some genes in 20 isolates of A. hydrophila. The results showed that 24% and 20% of the examined O. niloticus and C. gariepinus were infected with A. hydrophila respectively, with all (100%) showing a variety of clinical signs of septicemia. A. hydrophila isolates were all biofilm producers, with varied degrees of biofilm production. 79.5% of the isolates were multidrug-resistant and had a high multiple antimicrobial resistance index > 0.2. PCR analysis revealed that all isolates carried act and blaTEM genes but not carried int2 gene. Additionally, sul1, aer, tetA, int1, and qnrA genes were present in 75%, 60%, 55%, 55% and 45% of them, respectively. This study highlights the high incidence of multidrug-resistant pathogenic A. hydrophila in the infected fishes, posing a serious risk to humans and fish.
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Affiliation(s)
- Usama H Abo-Shama
- Department of Microbiology, Faculty of Veterinary Medicine, Sohag University, Sohag, 82524, Egypt.
| | - Amany A Abd El Raheem
- Department of Microbiology, Faculty of Veterinary Medicine, Sohag University, Sohag, 82524, Egypt
| | - Reem M Alsaadawy
- Department of Zoonoses, Faculty of Veterinary Medicine, Assiut University, Assiut, 71526, Egypt.
| | - Haitham H Sayed
- Department of Microbiology, Faculty of Veterinary Medicine, Sohag University, Sohag, 82524, Egypt
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3
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Ibrahim D, Shahin SE, Elnahriry SS, El-Badry SM, Eltarabili RM, Elazab ST, Ismail TA, Abd El-Hamid MI. Liposome encapsulating pine bark extract in Nile tilapia: Targeting interrelated immune and antioxidant defense to combat coinfection with Aeromonas hydrophila and Enterococcus faecalis. FISH & SHELLFISH IMMUNOLOGY 2025; 156:110031. [PMID: 39566669 DOI: 10.1016/j.fsi.2024.110031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2024] [Revised: 10/27/2024] [Accepted: 11/17/2024] [Indexed: 11/22/2024]
Abstract
Application of smart delivery systems for encapsulation of natural ingredients provides novel avenues and is being frequently developed. Thus, we aimed to highlight the effects of cyclosome liposomal pine bark extract (CL-PBE) on Nile tilapia growth, immunomodulation, antioxidant capacity and resistance against coinfection with Aeromonas hydrophila and Enterococcus faecalis and their associated virulence genes. The experiment was conducted on four fish groups receiving a control diet (control) along with three baseline meals supplemented with 200, 400 and 600 mg/kg diet of CL-PBE (CL-PBE 200, 400 and 600, respectively). At the end of the 12-weeks feeding trial, the tilapias were intraperitoneally challenged with virulent A. hydrophila strain and five days later, E. faecalis challenge was carried out. The results revealed that tilapias fed diets fortified with CL-PBE displayed significantly enhanced growth rate and feed conversion ratio in a dose-dependent manner. Moreover, we demonstrated that CL-PBE had potent antioxidant property presented by modulation of several markers of oxidative stress; substantial reductions in reactive oxygen species, hydrogen peroxide and malondialdehyde levels, an elevation in total antioxidant capacity and boosting glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activities in fish serum and muscle tissues. This was also correlated with augmenting the expression of CAT, SOD, GSH-Px, Nrf2 and caspase-1 genes alongside reducing those of COX-2, HSP70 and iNOS genes in response to CL-PBE. Our data demonstrated that CL-PBE fortification counteracted the overly pronounced inflammatory response-mediated induction of IL-1β, TNF-α, MHCII and TLR2 genes at the transcriptional levels post coinfection together with promotion in MUC2 and IL-10 genes expression. Notably, our findings displayed optimal well-functioning fish immune system post dietary supplementation of CL-PBE for the protection against coinfection with A. hydrophila and E. faecalis. This was evident from the decline of their counts and hence encompassing the capacity to reduce cumulative mortality percentage in conjunction with interference with their virulence via the significant downregulatory effects of CL-PBE on E. faecalis esp and gelE and A. hydrophila act and fla virulence genes. Taken together, our study strongly suggested dietary inclusion of CL-PBE for Nile tilapias with superior growth performance and significant economic benefits coupled with potent stimulatory effects on antioxidant capacity and immune response expediting our detailed understanding of how coinfection with A. hydrophila and E. faecalis was controlled.
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Affiliation(s)
- Doaa Ibrahim
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, 44511, Zagazig, Egypt.
| | - Sara E Shahin
- Department of Animal Wealth Development, Veterinary Economics and Farm Management, Faculty of Veterinary Medicine, Zagazig University, 44511, Zagazig, Egypt.
| | - Shimaa S Elnahriry
- Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Egypt.
| | - Sara M El-Badry
- Department of Animal Wealth Development, Veterinary Genetics and Genetic Engineering, Faculty of Veterinary Medicine, Zagazig University, Zagazig City 44519, Egypt.
| | - Reham M Eltarabili
- Department of Bacteriology, Immunology, and Mycology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Sara T Elazab
- Department of Pharmacology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt.
| | - Tamer Ahmed Ismail
- Department of Clinical Laboratory Sciences, Turabah University College, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.
| | - Marwa I Abd El-Hamid
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt.
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Kala K, Mallik SK, Shahi N, Pathak R, Sharma P, Chandra S, Patiyal RS, Pande V, Pandey N, Pande A, Pandey PK. Emergence of Aeromonas salmonicida subsp. masoucida MHJM250: unveiling pathological characteristics and antimicrobial susceptibility in golden mahseer, Tor putitora (Hamilton, 1822) in India. Vet Res Commun 2024; 48:3751-3772. [PMID: 39269671 DOI: 10.1007/s11259-024-10518-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 08/26/2024] [Indexed: 09/15/2024]
Abstract
Aeromonas salmonicida subsp. masoucida, designated as laboratory strain MHJM250, was characterized from a naturally infected farmed golden mahseer, Tor putitora. The infected fish exhibited clinical signs of erosion at the caudal fin and hemorrhage onx the ventral body surface. Molecular identification through 16 S rDNA and phylogenetic analysis revealed 100% similarity with a known strain A. salmonicida subsp. masoucida (MT122821.1). MHJM250 exhibited positive reactions for oxidase, catalase, esculin, MR-VP, O/F and utilized arginine and lysine. It also demonstrated siderophore activity, thrived at various NaCl concentrations, hydrolyzed gelatinase, skimmed milk and casinase. In vitro studies exhibited its hemolytic nature, significant biofilm production in glucose-rich tryptone soya broth and beta-hemolysis. MHJM250 didn't produce slime and was non-precipitated upon boiling. It showed crystal violet binding characteristics and auto-agglutination with relatively weak hydrophobicity (25%). In the challenge assay, intraperitoneal administration of MHJM250 to T. pitutora fingerlings at 108 CFU mL-1 resulted in pathogenicity with 3% mortality and mild hemorrhagic symptoms. Histopathological analysis revealed degenerative changes in gill, kidney, liver, muscle, and intestine samples. The bacterium displayed resistance to several antibiotics (µg/disc); ampicillin (10 µg), ampicillin/ sulbactam (10/10 µg), clindamycin (2 µg), linezolid (30 µg), penicillin G (10 µg) and rifampicin (5 µg) and varied minimum inhibitory concentrations against oxytetracycline, erythromycin and florfenicol. Transmission electron microscopy showed its rod-shaped structure with single polar flagellum and lophotrichous flagella. An investigation on the molecular basis for virulence factors of A. salmonicida subsp. masoucida MHJM250 may offer crucial understandings to formulate disease prevention and control strategies in aquaculture.
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Affiliation(s)
- Krishna Kala
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Sumanta Kumar Mallik
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Neetu Shahi
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Richa Pathak
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Prerna Sharma
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Suresh Chandra
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - R S Patiyal
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Veena Pande
- Department of Biotechnology, Bhimtal Campus, Kumaun University, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Nityanand Pandey
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Amit Pande
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India
| | - Pramod Kumar Pandey
- ICAR-Directorate of Coldwater Fisheries Research (ICAR-DCFR), Anusandhan Bhavan, Bhimtal, Nainital, 263 136, Uttarakhand, India.
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Ali NSM, Ngalimat MS, Lim BC, Hsu CC, Salleh A, Nazarudin MF, Yasin ISM, Azmai MNA. Efficacy of Feed-Based Genome-Free Bacterial Vaccine Against Aeromonas hydrophila Infection in Red Tilapia ( Oreochromis sp.). Vaccines (Basel) 2024; 12:1271. [PMID: 39591174 PMCID: PMC11598948 DOI: 10.3390/vaccines12111271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2024] [Revised: 09/21/2024] [Accepted: 09/25/2024] [Indexed: 11/28/2024] Open
Abstract
Aeromonas hydrophila causes motile Aeromonas septicemia (MAS), a disease with a high mortality rate in tilapia culture. Feed-based vaccines with the incorporation of inactivated whole-cell bacteria into the feed offer promising tools to control MAS. Currently, the incorporation of genome-free bacteria as bacterial vaccine through the implementation of SimCells® technology into the feed has become a particular interest. Background/Objectives: This study investigates the efficacy of a feed-based vaccine incorporating genome-free A. hydrophila (FBV-GFAH) against MAS infection in red tilapia. Methods: The vaccine was prepared and delivered at 5% fish body weight for three consecutive days in weeks 0 (prime vaccination) and 2 (first booster vaccination), orally. Throughout a five-week experimental period, the immune-related genes (IL-1β, MHC-II, CD4, IgT, and IgM) expression in the hindgut and head kidney of the fish was determined using RT-qPCR assay. Lysozyme (serum) and overall IgM (serum, gut lavage, and skin mucus) productions were also detected. Results: Fish vaccinated with FBV-GFAH showed a significant (p ≤ 0.05) improvement in relative percent survival compared with unvaccinated fish following bacterial challenge. FBV-GFAH induced the expression of immune-related genes in the hindgut and head kidney, especially after booster vaccination. Furthermore, serum lysozyme activity and overall IgM production in serum, skin mucus, and gut lavage were also significantly (p ≤ 0.05) improved in the FBV-GFAH vaccinated fish than the unvaccinated fish. Conclusions: This study showed that FBV-GFAH is a promising feed-based vaccine technology to control MAS in cultured tilapia.
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Affiliation(s)
- Nur Shidaa Mohd Ali
- Laboratory of Aquatic Animal Health and Therapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; (N.S.M.A.); (M.F.N.); (I.S.M.Y.)
| | - Mohamad Syazwan Ngalimat
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia;
| | - Boon Chuan Lim
- Oxford SimCell Ltd., Centre for Innovation and Enterprise, Begbroke Science Park, Begbroke, Oxfordshire OX5 1PF, UK; (B.C.L.); (C.-C.H.)
| | - Chia-Chen Hsu
- Oxford SimCell Ltd., Centre for Innovation and Enterprise, Begbroke Science Park, Begbroke, Oxfordshire OX5 1PF, UK; (B.C.L.); (C.-C.H.)
| | - Annas Salleh
- Laboratory Diagnosis, Department of Veterinary, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia;
| | - Muhammad Farhan Nazarudin
- Laboratory of Aquatic Animal Health and Therapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; (N.S.M.A.); (M.F.N.); (I.S.M.Y.)
| | - Ina Salwany Md Yasin
- Laboratory of Aquatic Animal Health and Therapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; (N.S.M.A.); (M.F.N.); (I.S.M.Y.)
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Mohammad Noor Amal Azmai
- Laboratory of Aquatic Animal Health and Therapeutics, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; (N.S.M.A.); (M.F.N.); (I.S.M.Y.)
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
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Kaur S, Kaur H, Kaur B, Naveen Kumar BT, Tyagi A, Singh P, Tanuj, Dubey S, Munang'andu HM. Isolating pathogenic multidrug-resistant Aeromonas hydrophila from diseased fish and assessing the effectiveness of a novel lytic Aeromonas veronii bacteriophage (AVP3) for biocontrol. Microb Pathog 2024; 196:106914. [PMID: 39241817 DOI: 10.1016/j.micpath.2024.106914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 08/18/2024] [Accepted: 09/02/2024] [Indexed: 09/09/2024]
Abstract
The increasing trend of antimicrobial resistance (AMR) pathogens in aquaculture makes it is imperative to find control measures for AMR pathogens causing high economic losses in aquaculture. In the present study, a multidrug resistance (MDR) Aeromonas hydrophila bacterium was isolated from kidney samples of diseased carp originating from a fish farm in Awankot, Rupnagar, Punjab, India. Moribund-infected fish exhibited large irregular hemorrhages on the external body surfaces, exophthalmia and fin-rot-like lesions. Phenotypic characterization using Rimler-Shotts (RS) media showed characteristic yellow color colonies and beta hemolysis on sheep blood agar. Genotyping using species-specific primers for the rpoB and gyrB genes characterized the isolate as A. hydrophila. The Multiple Antibiotic Resistance (MAR) index analysis showed that the isolated A. hydrophila had an MAR score of 0.29 signifying its resistance to more than three antibiotics, which underscores the need of finding treatment methods for MDR A. hydrophila isolates causing disease in aquaculture. Bacteriophages are considered a better eco-friendly alternative to antibiotics because of their inherent properties of not causing drug residues and resistance. Of the 13 phages tested, the Aeromonas veronii phage designated as AVP3, initially isolated against Aeromonas veronii, showed lytic activity against the MDR A. hydrophila isolated from diseased carp in this study. In addition, it also showed the lytic activity against Aeromonas spp. And A. caviae indicating that it had lytic properties against a wide host range within the Aeromonas species. This finding points to the potential efficacy of bacteriophages in mitigating pathogenic infections in aquaculture.
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Affiliation(s)
- Simran Kaur
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Harpreet Kaur
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Basmeet Kaur
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - B T Naveen Kumar
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India.
| | - Anuj Tyagi
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India.
| | - Prabjeet Singh
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Tanuj
- College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - Saurabh Dubey
- Nord University Faculty of Biosciences and Aquaculture, Post Box 1490, Bodø, Norway
| | - Hetron M Munang'andu
- Nord University Faculty of Biosciences and Aquaculture, Post Box 1490, Bodø, Norway
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Sripradite J, Thaotumpitak V, Atwill ER, Hinthong W, Jeamsripong S. Distribution of bacteria and antimicrobial resistance in retail Nile tilapia (Oreochromis spp.) as potential sources of foodborne illness. PLoS One 2024; 19:e0299987. [PMID: 38564611 PMCID: PMC10986973 DOI: 10.1371/journal.pone.0299987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
This study aimed to investigate AMR profiles of Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae isolated from Nile tilapia (Oreochromis spp.) (n = 276) purchased from fresh markets and supermarkets in Bangkok, Thailand. A sample of tilapia was divided into three parts: fish intestine (n = 276), fish meat (n = 276), and liver and kidney (n = 276). The occurrence of A. hydrophila, Salmonella, and V. cholerae was 3.1%, 7.4%, and 8.5%, respectively. A high prevalence of these pathogenic bacteria was observed in fresh market tilapia compared to those from supermarkets (p < 0.05). The predominant Salmonella serovars were Paratyphi B (6.4%), followed by Escanaba (5.7%), and Saintpaul (5.7%). All isolates tested positive for the virulence genes of A. hydrophila (aero and hly), Salmonella (invA), and V. cholerae (hlyA). A. hydrophila (65.4%), Salmonella (31.2%), and V. cholerae (2.9%) showed multidrug resistant isolates. All A. hydrophila isolates (n = 26) exhibited resistant to ampicillin (100.0%) and florfenicol (100.0%), and often carried sul1 (53.8%) and tetA (50.0%). Salmonella isolates were primarily resistant to ampicillin (36.9%), with a high incidence of blaTEM (26.2%) and qnrS (25.5%). For V. cholerae isolates, resistance was observed against ampicillin (48.6%), and they commonly carried qnrS (24.3%) and tetA (22.9%). To identify mutations in the quinolone resistance determining regions (QRDRs), a single C248A point mutation of C248A (Ser-83-Tyr) in the gyrA region was identified in six out of seven isolates of Salmonella isolates. This study highlighted the presence of antimicrobial-resistant pathogenic bacteria in Nile tilapia at a selling point. It is important to rigorously implement strategies for AMR control and prevention.
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Affiliation(s)
- Jarukorn Sripradite
- Department of Social and Applied Science, College of Industrial Technology, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand
| | - Varangkana Thaotumpitak
- Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Edward R. Atwill
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Woranich Hinthong
- Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Saharuetai Jeamsripong
- Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
- Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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Peng K, Chen M, Wang Y, Tian Z, Deng L, Li T, Feng Y, Ouyang P, Huang X, Chen D, Geng Y. Genotype diversity and antibiotic resistance risk in Aeromonas hydrophila in Sichuan, China. Braz J Microbiol 2024; 55:901-910. [PMID: 37999911 PMCID: PMC10920602 DOI: 10.1007/s42770-023-01187-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/31/2023] [Indexed: 11/25/2023] Open
Abstract
Sichuan is a significant aquaculture province in China, with a total aquaculture output of 1.72 × 106 tons in 2022. One of the most significant microorganisms hurting the Sichuan aquaculture is Aeromonas hydrophila, whose genotype and antibiotic resistance are yet unknown. This study isolated a total of 64 strains of A. hydrophila from various regions during September 2019 to June 2021 within Sichuan province, China. The technique of Multi-Locus Sequence Typing (MLST) was used for the purpose of molecular typing. Meanwhile, identification of antibiotic resistance phenotype and antibiotic resistance gene was performed. The findings of the study revealed that 64 isolates exhibited 29 sequence types (ST) throughout different regions in Sichuan, with 25 of these ST types being newly identified. Notably, the ST251 emerged as the predominant sequence type responsible for the pandemic. The resistance rate of isolated strains to roxithromycin was as high as 98.3%, followed by co-trimoxazole (87.5%), sulfafurazole (87.5%), imipenem (80%), amoxicillin (60%), and clindamycin (57.8%). Fifteen strains of A. hydrophila exhibited resistance to medicines across a minimum of three categories, suggesting the development of multidrug resistance in these isolates. A total of 63 ARGs were detected from the isolates, which mediated a range of antibiotic resistance mechanisms, with deactivation and efflux potentially serving as the primary mechanisms of antibiotic resistance. This study revealed the diversity of A. hydrophila genotypes and the risk of antibiotic resistance in Sichuan, providing reference for scientific and effective control of A. hydrophila infection.
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Affiliation(s)
- Kun Peng
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
| | - Mengzhu Chen
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
- Chengdu Animal Disease Prevention and Control Center, Chengdu, 60041, Sichuan, China
| | - Yilin Wang
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
| | - Ziqi Tian
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
| | - Longjun Deng
- Yalong River Hydropower Development Company Ltd, Chengdu, Sichuan, China
| | - Tiancai Li
- Yalong River Hydropower Development Company Ltd, Chengdu, Sichuan, China
| | - Yang Feng
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
| | - Ping Ouyang
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China
| | - Xiaoli Huang
- Department of Aquaculture, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Defang Chen
- Department of Aquaculture, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Yi Geng
- College of Veterinary Medicine, Sichuan Agricultural University, Huimin Road No. 211, Chengdu, 611130, Sichuan, China.
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Memesh R, Yasir M, Ledder RG, Zowawi H, McBain AJ, Azhar EI. An update on the prevalence of colistin and carbapenem-resistant Gram-negative bacteria in aquaculture: an emerging threat to public health. J Appl Microbiol 2024; 135:lxad288. [PMID: 38059867 DOI: 10.1093/jambio/lxad288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 09/22/2023] [Accepted: 12/05/2023] [Indexed: 12/08/2023]
Abstract
Aquaculture has been recognized as a hotspot for the emergence and spread of antimicrobial resistance genes conferring resistance to clinically important antibiotics. This review gives insights into studies investigating the prevalence of colistin and carbapenem resistance (CCR) among Gram-negative bacilli in aquaculture. Overall, a high incidence of CCR has been reported in aquatic farms in several countries, with CCR being more prevalent among opportunistic human pathogens such as Acinetobacter nosocomialis, Shewanella algae, Photobacterium damselae, Vibrio spp., Aeromonas spp., as well as members of Enterobacteriaceae family. A high proportion of isolates in these studies exhibited wide-spectrum profiles of antimicrobial resistance, highlighting their multidrug-resistance properties (MDR). Several mobile colistin resistance genes (including, mcr-1, mcr-1.1, mcr-2, mcr-2.1, mcr-3, mcr-3.1, mcr-4.1, mcr-4.3, mcr-5.1, mcr-6.1, mcr-7.1, mcr-8.1, and mcr-10.1) and carbapenemase encoding genes (including, blaOXA-48, blaOXA-55, blaNDM, blaKPC, blaIMI, blaAIM, blaVIM, and blaIMP) have been detected in aquatic farms in different countries. The majority of these were carried on MDR Incompatibility (Inc) plasmids including IncA/C, and IncX4, which have been associated with a wide host range of different sources. Thus, there is a risk for the possible spread of resistance genes between fish, their environments, and humans. These findings highlight the need to monitor and regulate the usage of antimicrobials in aquaculture. A multisectoral and transdisciplinary (One Health) approach is urgently needed to reduce the spread of resistant bacteria and/or resistance genes originating in aquaculture and avoid their global reach.
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Affiliation(s)
- Roa Memesh
- School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Special Infectious Agents Unit, King Fahd Medical Research Center and Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Muhammad Yasir
- Special Infectious Agents Unit, King Fahd Medical Research Center and Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ruth G Ledder
- School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Hosam Zowawi
- College of Medicine, King Saud bin Abdul-Aziz University for Health Science (KSAU-HS), Riyadh, Saudi Arabia
- King Abdullah International Medical Research Centre (KAIMRC), Riyadh, Saudi Arabia
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Andrew J McBain
- School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Esam I Azhar
- Special Infectious Agents Unit, King Fahd Medical Research Center and Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
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10
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Huang E, Yang X, Leighton E, Li X. Carbapenem resistance in the food supply chain. J Food Prot 2023; 86:100108. [PMID: 37244353 DOI: 10.1016/j.jfp.2023.100108] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Carbapenems are critically important antibiotic agents because they are considered the "last-resort" antibiotics for treating serious infections. However, resistance to carbapenems is increasing throughout the world and has become an urgent problem. Some carbapenem-resistant bacteria are considered urgent threats by the United States Centers for Disease Control and Prevention. In this review, we searched and summarized studies published mostly in the recent five years related to carbapenem resistance in three main areas in the food supply chain: livestock, aquaculture, and fresh produce. We have found that many studies have shown a direct or indirect correlation between carbapenem resistance in the food supply chain and human infections. Our review also revealed the worrisome incidences of the cooccurrence of resistance to carbapenem and other "last-resort" antibiotics, such as colistin and/or tigecycline, in the food supply chain. Antibiotic resistance is a global public health challenge, and more effort related to carbapenem resistance in the food supply chain for different food commodities is still needed in some countries and regions, including the United States. In addition, antibiotic resistance in the food supply chain is a complicated issue. Based on the knowledge from current studies, only restricting the use of antibiotics in food animal production might not be enough. Additional research is needed to determine factors contributing to the introduction and persistence of carbapenem resistance in the food supply chain. Through this review, we hope to provide a better understanding of the current state of carbapenem resistance, and the niches of knowledge that are needed for developing strategies to mitigate antibiotic resistance, especially carbapenem resistance in the food supply chain.
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Affiliation(s)
- En Huang
- Department of Environmental Health Sciences, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA
| | - Xu Yang
- Department of Nutrition and Food Science, California State Polytechnic University Pomona, 3801 West Temple Ave, Pomona, CA 91768, USA
| | - Elizabeth Leighton
- Department of Microbiology, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI 54601, USA
| | - Xinhui Li
- Department of Microbiology, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI 54601, USA.
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Gad T, Abd El-Moaty A, Elkenany R. Decontamination of Marketed Mullet (Mugil cephalus) Infected with Aeromonas hydrophila by Organic Acids. TRENDS IN AGRICULTURAL SCIENCES 2023; 2:99-105. [DOI: 10.17311/tas.2023.99.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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12
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Abdella B, Abozahra NA, Shokrak NM, Mohamed RA, El-Helow ER. Whole spectrum of Aeromonas hydrophila virulence determinants and the identification of novel SNPs using comparative pathogenomics. Sci Rep 2023; 13:7712. [PMID: 37173388 PMCID: PMC10182093 DOI: 10.1038/s41598-023-34887-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023] Open
Abstract
Aeromonas hydrophila is a ubiquitous fish pathogen and an opportunistic human pathogen. It is mostly found in aquatic habitats, but it has also been isolated from food and bottled mineral waters. It causes hemorrhagic septicemia, ulcerative disease, and motile Aeromonas septicemia (MAS) in fish and other aquatic animals. Moreover, it might cause gastroenteritis, wound infections, and septicemia in humans. Different variables influence A. hydrophila virulence, including the virulence genes expressed, host susceptibility, and environmental stresses. The identification of virulence factors for a bacterial pathogen will help in the development of preventive and control measures. 95 Aeromonas spp. genomes were examined in the current study, and 53 strains were determined to be valid A. hydrophila. These genomes were examined for pan- and core-genomes using a comparative genomics technique. A. hydrophila has an open pan-genome with 18,306 total genes and 1620 genes in its core-genome. In the pan-genome, 312 virulence genes have been detected. The effector delivery system category had the largest number of virulence genes (87), followed by immunological modulation and motility genes (69 and 46, respectively). This provides new insight into the pathogenicity of A. hydrophila. In the pan-genome, a few distinctive single-nucleotide polymorphisms (SNPs) have been identified in four genes, namely: D-glycero-beta-D-manno-heptose-1,7-bisphosphate 7-phosphatase, chemoreceptor glutamine deamidase, Spermidine N (1)-acetyltransferase, and maleylpyruvate isomerase, which are present in all A. hydrophila genomes, which make them molecular marker candidates for precise identification of A. hydrophila. Therefore, for precise diagnostic and discrimination results, we suggest these genes be considered when designing primers and probes for sequencing, multiplex-PCR, or real-time PCR.
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Affiliation(s)
- Bahaa Abdella
- Aquaculture Department, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt.
| | - Nourhan A Abozahra
- Aquaculture Department, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt
| | - Nermeen M Shokrak
- Aquaculture Department, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt
| | - Radi A Mohamed
- Aquaculture Department, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt
| | - Ehab R El-Helow
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, 21511, Egypt
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13
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Cytotoxicity and Antimicrobial Resistance of Aeromonas Strains Isolated from Fresh Produce and Irrigation Water. Antibiotics (Basel) 2023; 12:antibiotics12030511. [PMID: 36978377 PMCID: PMC10044025 DOI: 10.3390/antibiotics12030511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
The genus Aeromonas has received constant attention in different areas, from aquaculture and veterinary medicine to food safety, where more and more frequent isolates are occurring with increased resistance to antibiotics. The present paper studied the interaction of Aeromonas strains isolated from fresh produce and water with different eukaryotic cell types with the aim of better understanding the cytotoxic capacity of these strains. To study host-cell pathogen interactions in Aeromonas, we used HT-29, Vero, J774A.1, and primary mouse embryonic fibroblasts. These interactions were analyzed by confocal microscopy to determine the cytotoxicity of the strains. We also used Galleria mellonella larvae to test their pathogenicity in this experimental model. Our results demonstrated that two strains showed high cytotoxicity in epithelial cells, fibroblasts, and macrophages. Furthermore, these strains showed high virulence using the G. mellonella model. All strains used in this paper generally showed low levels of resistance to the different families of the antibiotics being tested. These results indicated that some strains of Aeromonas present in vegetables and water pose a potential health hazard, displaying very high in vitro and in vivo virulence. This pathogenic potential, and some recent concerning findings on antimicrobial resistance in Aeromonas, encourage further efforts in examining the precise significance of Aeromonas strains isolated from foods for human consumption.
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Yang S, Jin D, Li H, Jiang L, Cui J, Huang W, Rang J, Li Y, Xia L. Screening of new Paenibacillus polymyxa S3 and its disease resistance of grass carp (Ctenopharyngodon idellus). JOURNAL OF FISH DISEASES 2023; 46:17-29. [PMID: 36097971 DOI: 10.1111/jfd.13714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
A new strain of Paenibacillus polymyxa S3 with antagonistic effects on 11 major fish pathogens (especially Aeromonas hydrophila), but had no toxicity to grass carp, was screened from the sediment of fishponds. In vivo colonization studies showed that strain S3 could be colonized and distributed in the gill and abdomen of the grass carp. Bioassay results showed that the weight growth rate of grass carp in the strain S3 oral group (16.01%) and strain S3 immersion group (16.44%) was significantly higher than those of the control group (8.61%). At the same time, the activities of ACP, AKP, CAT and GSH-Px in the serum of grass carp in oral and immersion groups were significantly higher than those of the control group. In addition, the treatment with strain S3 could significantly upregulate the expression of the antioxidant-related genes and immune-related genes Keap1, Nrf2, C3, LZM, IgM, TLR-4 and MyD-88 in grass carp tissues. The challenge test showed that strain S3 treatment significantly increased the survival rate of grass carp infected with Aeromonas hydrophila. Whole genome sequencing analysis showed that strain S3 had 16 active metabolite gene clusters, indicating that it had abundant gene resources, which provided important support for its development for fish microecological preparations. In summary, a new strain of Paenibacillus polymyxa S3 with antibacterial activity against a variety of fish pathogens was screened in this study and its probiotic function was evaluated, proving its potential value in fisheries.
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Affiliation(s)
- Shijia Yang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Duo Jin
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Hui Li
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Lingzhi Jiang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Jun Cui
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Weitao Huang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Jie Rang
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - YunLong Li
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
| | - Liqiu Xia
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Provincial Key Laboratory of Microbial Molecular Biology, College of Life Science, Hunan Normal University, Changsha, China
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Youssef HA, Ayoub HF, Soror EI, Matter AF. Virulence genes contributing to Aeromonas veronii pathogenicity in Nile tilapia ( Oreochromis niloticus): approaching the development of live and inactivated vaccines. AQUACULTURE INTERNATIONAL : JOURNAL OF THE EUROPEAN AQUACULTURE SOCIETY 2022; 31:1253-1267. [PMID: 36439703 PMCID: PMC9676859 DOI: 10.1007/s10499-022-01023-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/09/2022] [Indexed: 05/29/2023]
Abstract
This study aimed to develop and evaluate live and inactivated vaccines to Aeromonas veronii pathogenicity in Nile tilapia. Therefore, five well-identified Aeromonas veronii isolates, including A (HY1), A (HY2), A (HY3), A (HY4), and A (HY6) isolated from diseased Nile tilapia (Oreochromis niloticus), were used for vaccine preparation. Virulence genes detected by a polymerase chain reaction (PCR) and lethal dose determination were conducted. Nile tilapia, each with a body weight of 25 ± 0.5 g were divided into six experimental groups (each of 20): T1 group (control), fish were injected with saline as a negative control, T2 group (formalin-killed vaccine) for the A (HY2) strain, T3 group ( formalized killed vaccine) for the A (HY4), T4 group (autoclaved vaccine) for the A (HY2), T5 group (autoclaved vaccine) for A (HY4), and T6 (live vaccine) for A (HY1), triplicate. At the end of the immunization period, all groups were challenged by A. veronii, A (HY2). Blood samples were drawn 21 days post-immunization and 3 days after the challenge test for antibody titer assay. The results showed that the pathogenicity of strains A (HY2) and A (HY4) was the strongest, as the lethality rates (LR) were 100% and 90%, respectively, whereas the pathogenicity was moderate for strains A (HY3) and A (HY6) (LR 60% for each). A (AY1) was the weakest strain as no dead fish was found for this strain. The presence of alt, act, aerolysin, lipase, and fla genes as the main cause of the pathogenesis. The best protective efficacy was obtained from the live vaccine, A (HY1) with a protective rate of about 94.12% (relative percentage of survival, RPS), compared to autoclaved killed vaccines and formalin-killed vaccines. Based on immunoglobulin estimation (IgM) and RPS%, our data concluded that A (HY1) live vaccine had the best vaccine prophylactic effect against the highly pathogenic strain A(HY2).
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Affiliation(s)
- Hadeer A. Youssef
- Department of Aquatic Animals Medicine, Faculty of Veterinary Medicine, MoshtohorBenha University, Benha, Egypt
| | - Hala F. Ayoub
- Department of Fish Health and Management, Central Laboratory for Aquaculture Research (CLAR) Agricultural Research Center (ARC), Abbassa, Sharqia Egypt
| | - Eman I. Soror
- Department of Aquatic Animals Medicine, Faculty of Veterinary Medicine, MoshtohorBenha University, Benha, Egypt
| | - Aya F. Matter
- Department of Aquatic Animals Medicine, Faculty of Veterinary Medicine, MoshtohorBenha University, Benha, Egypt
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