Emergence of extensively drug-resistant Aeromonas hydrophila complex isolated from wild Mugil cephalus (striped mullet) and Mediterranean seawater

Abstract

Background and Aim: Antibiotic resistance has been a progressively documented problem, resulting in treatment failure in humans and animals. This study aimed to investigate the antimicrobial susceptibility and virulence of extensively drug-resistant (XDR) Aeromonas spp. in wild Mugil cephalus and its surrounding seawater along the coastal road of Port Said, Egypt. Materials and Methods: Specimens were examined bacteriologically, confirmed biochemically, and tested for their sensitivity against 11 antimicrobial agents. Molecular confirmation of the obtained isolates by 16S rRNA was performed, followed by the detection of antimicrobial resistance and virulence genes. Results: Aeromonas spp. was recovered from fish (44%) and water samples (36%). A. hydrophila was the most prevalent identified strain, followed by Aeromonas sobria, Aeromonas caviae, and Aeromonas schubertii. Moreover, 90% of the tested isolates were multidrug-resistant (MDR), while 26.67% were XDR. Tested isolates were resistant to β-lactams and sulfonamides (100%), oxytetracycline (90%), and streptomycin (62.22%) but completely susceptible to cefotaxime. XDR isolates successfully amplified resistance genes (blaTEM, sul1, and tetA(A)) but not the (aadA1) gene, although there was phenotypic resistance to streptomycin on plates. All XDR isolates carry the cytotoxic enterotoxin gene (act), but alt gene was detected in only one isolate (12.5%). Conclusion: Data in this study provide a recent update and highlight the role of wild mullet and seawater as reservoirs for MDR and XDR Aeromonas spp. that may pose a risk to humans as food-borne infection or following direct contact.

Incidence of aac(6′)-Ib-cr Mediated by Class 1 Integrons in Aeromonas Species Isolated from Diseased Oreochromis niloticus

“…These included genes conferring ampicillin resistance (bla TEM ) and plasmidmediated quinolone resistance (aac(6′)-Ib-cr). These findings align with existing literature, which consistently reports the presence of bla TEM in all Aeromonas isolates (100%) [23,24]. A separate study conducted in Egypt revealed that the bla TEM gene was detected in all A. hydrophila strains (100%) isolated from Nile tilapia and catfish samples, while 83.33% of A. caviae strains carried the bla TEM gene [25].…”

Prevalence and antibiotic resistance of Aeromonas schubertii causing internal white spot disease on snakehead fish, Channa striata, in the Mekong Delta, Vietnam

“…Consistent with previous studies (as indicated in Table 2), A. schubertii isolated from an aquatic host exhibited MAR against the antibiotics tested. Yano et al (2015) reported multiple antimicrobial resistances (4 out of 14 antibiotics) from A. schubertii isolated from shrimp, while Eid et al (2022) reported MAR in two isolates recovered from Mugil cephalus with two MARPs including 7 out of 11 and 4 out of 11 antibiotics for each. In this study, 15 MARPs were found in 25 isolates of A. schubertii (Table 1), and the hierarchical clustering analysis of their antibiotic resistance (Figure 3b) may indicate its cross‐invasion between ponds and fish farms.…”

A Comprehensive Review for the Surveillance of Human Pathogenic Microorganisms in Shellfish

“…Among the bacterial pathogens, the Vibrio species, including V. parahaemolyticus , V. cholerae and V. vulnificus , have been extensively studied as key agents responsible for shellfishborne diseases, especially in shellfish like oysters, mussels and ark shells, and particularly during warmer months, when their populations surge [ 17 , 18 , 19 ]. More recent research has shed light on Aeromonas pathogenic species, with studies emcompassing the virulence and emergence of drug-resistant Aeromonas in seafood [ 20 , 21 , 22 ]. The authors advocate for paying increased attention to these pathogens, particularly considering the context of global warming and its effect on water temperatures.…”