Antimicrobial Resistance and Incidence of Integrons in Aeromonas Species Isolated from Diseased Freshwater Animals and Water Samples in Iran

Abstract

Aeromonas spp. is one of the major pathogens of freshwater animals. There has been little research on the genetics of antimicrobial resistance associated with it in Iranian aquaculture. To remedy this lack in research, 74 multi-drug-resistant Aeromonas spp. were isolated from farmed diseased carp, trout, sturgeon, ornamental fish, crayfish, and corresponding water samples and examined for genomic integron sequences. Class 1 integrons, containing seven types of integron cassette arrays (dfrA1-aadA1, dfrA1-orfC, dfrA12-aadA2, dfrA12-orfF-aadA2, dfrA15, dfrB4-catB3-aadA1, aac(6’)-Ib-cr-arr3-dfrA27) were found in 15% of the resistant isolates; no class 2 integrons were detected in any of the resistant isolates. As some tested isolates were resistant to more than two groups of antibiotics, our results demonstrated that freshwater animals in Iran could be a source of multiply drug-resistant Aeromonas spp. This finding suggests that the origin of the antimicrobial resistance of these animals be placed under increased surveillance in the future and that the use of antimicrobials be limited in aquaculture.

Characterization and Antimicrobial Resistance of Environmental and Clinical Aeromonas Species Isolated from Fresh Water Ornamental Fish and Associated Farming Environment in Sri Lanka

“…It is interesting to note that 7.45% (12/161) of our isolates carried class 2 integron gene cassette regions with fragment sizes ranging from 450 bp-1800 bp. The high incidence of Class 2 integrons was an important finding in this study as the presence of integron 2 has not been detected in similar studies done using aeromonads from ornamental fish and other freshwater fish [75]. Moreover, 6.8% of our strains contained both types of integrons.…”

Aeromonas hydrophila RIT668 and Citrobacter portucalensis RIT669—Potential Zoonotic Pathogens Isolated from Spotted Turtles

“…The emergence of multi-drug resistance in Aeromonas spp. strains in water environments [ 130 ] and resistance determinants against last resort antibiotics, such as colistin [ 105 , 131 ] make A. hydrophila species increasingly dangerous pathogens. Multidrug resistant C. freundii which produce both carbapenemase and metallo-beta-lactamase have been reported, which resisted all tested antibiotics except tetracycline have been isolated in China [ 132 ], while a potentially zoonotic superbug C. portucalensis strain is known [ 24 ].…”

The microbial safety of fish and fish products: Recent advances in understanding its significance, contamination sources, and control strategies

“…First, various human pathogens and spoilage microorganisms as well as ARB have been detected in water samples collected from the fish living/rearing environment. The reported ARB include Salmonella spp., Aeromonas spp., Acinetobacter spp., Pseudomonas spp., Bacillus spp., Pseudoalteromonas spp., Proteus spp., and many others (Budiati et al., 2013; Hoa et al., 2011; Naviner et al., 2011; Ranjbar, Salighehzadeh, & Sharifiyazdi, 2019; Shah, Colquhoun, Nikuli, & Sorum, 2012; Zdanowicz, Mudryk, & Perlinski, 2020). Furthermore, ARGs were detected in water microbiota using culture‐independent methods, for example, quantitative PCR (qPCR) and shotgun metagenomic sequencing (Klase et al., 2019; Seyfried, Newton, Rubert, Pedersen, & McMahon, 2010; Shah et al., 2012; Wang et al., 2018; Xiong et al., 2015; Zeng, Liao, Terhune, & Wang, 2019).…”

“…Furthermore, ARGs were detected in water microbiota using culture‐independent methods, for example, quantitative PCR (qPCR) and shotgun metagenomic sequencing (Klase et al., 2019; Seyfried, Newton, Rubert, Pedersen, & McMahon, 2010; Shah et al., 2012; Wang et al., 2018; Xiong et al., 2015; Zeng, Liao, Terhune, & Wang, 2019). Last but not least, MGEs, which can transfer ARGs to other bacteria in fish and the environment, have also been isolated from water microbiota (Budiati et al., 2013; Ranjbar et al., 2019). For example, L. monocytogenes has been isolated from fish‐farm water in Finland and Denmark (Hansen, Vogel, & Gram, 2006; Katzav, Hyvonen, Muje, Rantala, & Von Wright, 2006).…”

“…Aeromonas spp. resistant to multiple antibiotics was recovered from fish‐farm water in Iran (Ranjbar et al., 2019). Of those resistant isolates, 15% contained class 1 integrons, which contain seven types of integron cassette arrays and are proven to transport different ARG cassettes.…”