Virulent and Multiple Antimicrobial Resistance <i>Aeromonas hydrophila</i> Isolated from Diseased Nile Tilapia Fish (<i>Oreochromis niloticus</i>) in Egypt with Sequencing of Some Virulence-Associated Genes

Abstract

Aeromonas hydrophila is a major waterborne pathogen, which induces various diseases in freshwater fish with the capability for zoonotic potential. This study was applied to investigate the prevalence of A. hydrophila in diseased Nile tilapia fish, genetic characterization of the virulence encoding genes (act, aerA, alt, and ast genes) , and antibiotic susceptibility. Out of the 500 diseased Nile tilapia fish samples, 70% (350/500) Aeromonas species were isolated. From which 53.4% (187/350) of Aeromonas hydrophila strains were identified. A. hydrophila was detected in kidneys, followed by liver, spleen, intestine, and gills. The results of virulotyping displayed the presence of act, and aerA genes in a high percentage of 40%, followed by alt gene (30%) , but ast gene was not detected (0%) in A. hydrophila strains. Based on DNA sequence analysis of three virulence associated-genes (act, aerA, and alt genes) , the phylogenetic tree showed the genetic relationship with related species. Finally, the antibiotic susceptibility tests revealed high resistance toward chloramphenicol (67.4%) , followed by amikacin (51.9%) and gentamicin (47.1%) , whereas a high sensitivity was exhibited toward meropenem (90.9%) , followed by ciprofloxacin (84.2%) , amoxicillin-clavulanic acid (73.3%) and trimethoprimsulfamethoxazole (64.2%) . The multidrug-resistant A. hydrophila strains were observed in 69.0% of strains with six resistance patterns.

Whole spectrum of Aeromonas hydrophila virulence determinants and the identification of novel SNPs using comparative pathogenomics

“…Pathogenomics is a field of science that uses genomics research to assess the pathogenicity potential of bacteria. However, most of the published epidemiological studies consider only a few genes 13 , 18 , 42 . In the current study, 312 virulence genes were detected in the A. hydrophila pan-genome.…”

Virulence genes contributing to Aeromonas veronii pathogenicity in Nile tilapia (Oreochromis niloticus): approaching the development of live and inactivated vaccines

“…Every day, fish waste was drained and 50% of the water was replaced with aerated and dechlorinated water from the storage tank. Groups T2, T3, T4, T5, and T6 received 0.1 ml from the prepared vaccines as described previously (Surgha et al 2021 ). The T1 control group received a sterile saline post-intraperitoneal injection (I/P) and stay as a negative control.…”

“…However, this can lead to the development of antibiotic resistance and antimicrobial residues in aquaculture (Vivekanandhan et al 2002 ). A recent study by Salah et al ( 2021 ) demonstrated a multi-drug resistance of Aeromonas hydophila chloramphenicol (67.4%), followed by amikacin (51.9%) and gentamicin (47.1%).…”

Cytotoxicity and Antimicrobial Resistance of Aeromonas Strains Isolated from Fresh Produce and Irrigation Water

“…The genus Aeromonas has received constant attention from different areas such as aquaculture and veterinary medicine [ 1 , 2 , 3 ], food safety [ 4 , 5 ], and clinical human microbiology [ 6 , 7 ]. Human infections by Aeromonas are more frequent and these strains have an increasing resistance to antibiotics [ 8 , 9 ]. Therefore, it is not only necessary to better understand antibiotic resistance in these species, but their virulence and pathogenicity mechanisms [ 10 ] as well.…”