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Resistance of Aeromonas hydrophila isolates to antimicrobials and sanitizers

Resistência de isolados de Aeromonas hydrophila a antimicrobianos e sanitizantes

ABSTRACT:

In recent decades, Aeromonas hydrophila has emerged as a foodborne bacterial pathogen of public health concern, especially as it exhibits resistance to the major chemical sanitizers commonly used in the food industry. Meanwhile, this pathogen may be spread from diseased fish flesh through the contamination of equipment contact surfaces during food processing, thus posing a food safety risk. Thise determined the susceptibility profiles of retail fish-borne A. hydrophila isolates to 24 common antibiotics and five major sanitizers used in the food industry. The polymerase chain reaction technique was used to confirm all A. hydrophila isolates to the species level, and the agar diffusion method was applied to determine the antimicrobial susceptibility profiles. All isolates were confirmed to be A. hydrophila species. This bacterium was observed to have resistance to multiple antibiotics, with the highest resistance index being for those of the beta-lactam class. Additionally, the isolates showed high resistance to four of the five chemical sanitizers tested, with the highest resistance rate being toward sodium hypochlorite. The results suggested that A. hydrophila isolates with multiple resistance to the antimicrobials and main sanitizers used in the food industry can be found in retail fish sold in the Cuiabá region of Mato Grosso, Brazil.

Key words:
fish; microorganisms; pathogen; antibiogram; susceptibility to sanitizers

RESUMO:

Aeromonas hydrophila emergiu nas últimas décadas como um patógeno humano relevante. O fato desse patógeno alimentar emergente apresentar resistência antimicrobiana é um desafio considerável para as Agências de Saúde devido à resistência desta espécie aos principais sanitizantes químicos comumente utilizados na indústria alimentícia em que representa um risco à segurança dos alimentos, uma vez que pode contribuir para a disseminação desta bactéria na carne de peixes e levar à contaminação da superfície de contato dos equipamentos durante o processamento dos alimentos. Este estudo teve como objetivo determinar os padrões de suscetibilidade de isolados de A. hydrophila de peixes comercializados no varejo a 24 antibióticos comuns e cinco principais sanitizantes utilizados nas indústrias alimentícias. Neste estudo, todos os isolados de A. hydrophila foram confirmados em nível de espécie pela técnica de Reação em Cadeia da Polimerase (PCR). A técnica de difusão em ágar foi utilizada para determinar o perfil de suscetibilidade antimicrobiana frente aos 24 antibióticos testados e para avaliar a suscetibilidade aos principais sanitizantes utilizados na indústria alimentícia. A partir dos resultados, todos os isolados foram confirmados como sendo da espécie A. hydrophila pela técnica de PCR molecular. Observou-se A. hydrophila com perfil de resistência a múltiplos antibióticos, em que os da classe dos Beta-Lactâmicos foram os antimicrobianos com maior índice de resistência. Além disso, a suscetibilidade aos sanitizantes apresentou alta resistência em quatro dos cinco sanitizantes testados, sendo o hipoclorito de sódio foi o sanitizante químico com maior índice de resistência entre os isolados deste estudo. Os resultados sugerem que isolados de A. hydrophila com perfil de resistência a antimicrobianos e aos principais sanitizantes utilizados na indústria alimentícia podem ser encontrados em peixes comercializados no varejo da região de Cuiabá/Mato Grosso.

Palavra-chave:
peixe; micro-organismos; patógeno; antibiograma; suscetibilidade a sanitizantes

INTRODUCTION:

Fish constitutes an important food in the human diet. However, they may contain Aeromonashydrophila,a bacterial species found ubiquitously in aquatic environments (CHATTOPADHYAY & ADHIKARI, 2014CHATTOPADHYAY, P.; ADHIKARI, S. Fish - Catching and Handling. Encyclopedia of Food Microbiology, p.923-931, 2014. Available from: <Available from: https://doi.org/10.1016/B978-0-12-384730-0.00124-5 >. Accessed: Dec. 20, 2022. doi: 10.1016/B978-0-12-384730-0.00124-5.
https://doi.org/10.1016/B978-0-12-384730...
). This human pathogen represents a serious health risk owing to its production of enterotoxins, hemolysins, and cytotoxins as well as other metabolites related to its pathogenicity and virulence (DASKALOV, 2006DASKALOV, H. The importance of Aeromonas hydrophila in food safety. Food Control, v.17, n.6, p.474-483, 2006. Available from: <Available from: https://doi.org/10.1016/j.foodcont.2005.02.009 >. Accessed: Apr. 17, 2022. doi:10.1016/j.foodcont.2005.02.009.
https://doi.org/10.1016/j.foodcont.2005....
; IGBINOSA et al., 2012IGBINOSA, I. H. et al. Emerging aeromonas species infections and their significance in public health. Scientific World Journal, 2012. Available from: <Available from: https://doi.org/10.1100/2012/625023 >. Accessed: Apr. 17, 2022. doi: 10.1100/2012/625023.
https://doi.org/10.1100/2012/625023...
; STRATEV &; ODEYEMI, 2016STRATEV, D.; ODEYEMI, O. A. Antimicrobial resistence of Aeromonas hydrophila isolated from different food soucers: A mini-review. Journal of Infection and Public Health, v.9, n.5, p.535-544, 2016. Available from: <Available from: https://doi.org/10.1016/j.jiph.2015.10.006 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.jiph.2015.10.006.
https://doi.org/10.1016/j.jiph.2015.10.0...
; PESSOA et al., 2019PESSOA, R. G. et al. The genus Aeromonas: A general approach. Microbial Pathogenesis, v.130, p.81-94, 2019. Available from: <Available from: https://doi.org/10.1016/j.micpath.2019.02.036 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.micpath.2019.02.036.
https://doi.org/10.1016/j.micpath.2019.0...
; FERNÁNDEZ-BRAVO & FIGUERAS, 2020FERNÁNDEZ-BRAVO, A.; FIGUEIRAS, M. J. An update on the genus Aeromonas: Taxonomy, Epidemiology, and Pathogenicity. Microorganisms, v.8, 2020. Available from: <Available from: http://dx.doi.org/10.4067/S0716-10182012000100008 >. Accessed: Apr. 17, 2022. doi: 10.4067/S0716-10182012000100008.
http://dx.doi.org/10.4067/S0716-10182012...
). More importantly, it has shown resistance to different antimicrobials (PRAVEEN et al., 2016PRAVEEN, P. K. et al. Incidence of Aeromonas spp. infection in fish and chicken meat and its related public health hazards: A review. Veterinary World,v.9, n.1, p.6-11, 2016 Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819351 >. Accessed: Apr. 17, 2022. doi: 10.14202/vetworld.2016.6-11.
https://www.ncbi.nlm.nih.gov/pmc/article...
). Although several studies have reported the presence of Aeromonas in various food sources, including retail fish (ABD-EL-MALEK, 2017ABD-EL-MALEK, A. M. Incidence and virulence characteristics of Aeromonas spp. in fish. Veterinary World, v.10, p.34-37, 2017. Available from: <Available from: http://https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5301177/ >. Accessed: Dec. 20, 2022. doi: 10.14202/vetworld.2017.34-37.
http://https://www.ncbi.nlm.nih.gov/pmc/...
; PASTRO et al., 2019PASTRO, D. C. et al. Use of molecular techniques for the analysis of the microbiological quality of fish marketed in the municipality of Cuiabá, Mato Grosso, Brazil. Food Science and Technology, v.39, n.1, p.146-151, 2019. Available from: <Available from: http://https://www.scielo.br/j/cta/a/s8TLvzdbpZgfHK8DrwgsM5w/?format=html⟨=en >. Accessed: Dec. 20, 2022. doi: 10.1590/fst.40217.
http://https://www.scielo.br/j/cta/a/s8T...
; SANTOS et al., 2019SANTOS, E. J. R. et al. Hygienic-sanitary quality of tambaqui (Colossomamacropomum) sold in the city of São Luís - MA. Ciência Animal Brasileira, v.20, n.1-12, 2019. Available from: <Available from: https://doi.org/10.1590/1809-6891v20e-46537 >. Accessed: Apr. 18, 2022. doi: 10.1590/1809-6891v20e-46537.
https://doi.org/10.1590/1809-6891v20e-46...
), there is no specific legislation that sets standards for this microorganism in Brazil, resulting in a potential health risk to consumers.

Antimicrobial resistance in emerging pathogens is a potential threat to human health and has become one of the biggest challenges to public health systems worldwide (MCEWEN & COLLIGNON, 2018MCEWEN, S. A.; COLLIGNON, P. J. Antimicrobial resistance: a One Health Perspective. Microbiology Spectrum, v.6, n.2, 2018. Available from: <Available from: https://journals.asm.org/doi/full/10.1128/microbiolspec.ARBA-0009-2017 >. Accessed: Dec. 20, 2022. doi: 10.1128/microbiolspec.ARBA-0009-2017.
https://journals.asm.org/doi/full/10.112...
). Most antimicrobials are common to veterinary and human use, which increases the potential of resistance development in pathogens that infect humans and animals and intensifies the risk of spread through food contamination (EMA, 2014EMA- European Medicines Agency. Answers to the requests for scientific advice on the impact on public health and animal health of the use of antibiotics in animals. European Medicines Agency, 2014. Available from: <Available from: https://www.ema.europa.eu/ >. Accessed: Apr. 20, 2022.
https://www.ema.europa.eu/...
; STRATEV & ODEYEMI, 2016STRATEV, D.; ODEYEMI, O. A. Antimicrobial resistence of Aeromonas hydrophila isolated from different food soucers: A mini-review. Journal of Infection and Public Health, v.9, n.5, p.535-544, 2016. Available from: <Available from: https://doi.org/10.1016/j.jiph.2015.10.006 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.jiph.2015.10.006.
https://doi.org/10.1016/j.jiph.2015.10.0...
).

The infective dose of A. hydrophila is not yet fully understood (PARK et al., 2021PARK, S. M. et al. Pathogenicity and seasonal variation of Aeromonas hydrophila isolated from seafood and ready-to-eat sushi in South Korea. Food Research International, v.147, 2021. Available from: <Available from: https://doi.org/10.1016/j.foodres.2021.110484 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.foodres.2021.110484.
https://doi.org/10.1016/j.foodres.2021.1...
). According to GONZÁLEZ-SERRANO et al. (2002GONZÁLEZ-SERRANO, C. J. et al. Virulence markers in Aeromonas hydrophila and Aeromonas veronii biovar sobria isolates from freshwater fish and from a diarrhoea case. Journal of Applied Microbiology, v.93, p.414-419, 2002. Available from: <Available from: https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1046/j.1365-2672.2002.01705.x >. Accessed: Dec. 20, 2022. doi: 10.1046/j.1365-2672.2002.01705.x.
https://sfamjournals.onlinelibrary.wiley...
), an efficient cooking process can inactivate this pathogen, but insufficient cooking and cross-contamination will pose a potential health risk, primarily in immunosuppressed individuals, children, and the elderly.

Pathogens that exhibit resistance to antimicrobials also exhibit resistance to sanitizers (ROZMAN et al., 2021ROZMAN, U. et al. Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review. Microorganisms, v.9, n.12, p.2550, 2021. Available from: <Available from: https://www.mdpi.com/2076-2607/9/12/2550 >. Accessed: Apr. 18, 2022. doi: 10.3390/microorganisms9122550.
https://www.mdpi.com/2076-2607/9/12/2550...
). The effectiveness of sanitizers, especially against gram-negative bacteria, is crucial in food manufacturing and processing units (ODEYEMI et al., 2022ODEYEMI, F. M. et al. Integrated poultry-fish farming system encourages multidrug-resistant gram-negative bacteria dissemination in pond environment and fishes. Aquaculture, v.1, n.15, 2022. Available from: <Available from: https://doi.org/10.1016/j.aquaculture.2021.737558 >. Accessed: Apr. 18, 2022. doi: 10.1016/j.aquaculture.2021.737558.
https://doi.org/10.1016/j.aquaculture.20...
), and their ineffectiveness can represent a threat to food safety and consumer health (GONÇALVES, 2011GONÇALVES, A. A. Tecnologia do pescado: ciência tecnologia, inovação e legislação. 1ª ed. São Paulo: Atheneu, p.624, 2011.; SHENG & WANG, 2021SHENG, L.; WANG, L. The microbial safety of fish and fish products: Recent advances in understanding its significance, contamination sources, and control strategies. Comprehensive Reviews in Food Science and Food Safety, v.20, p.738-789, 2021. Available from: <Available from: https://ift.onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12671 >. Accessed: Apr. 27, 2022. doi: 10.1111/1541-4337.12671.
https://ift.onlinelibrary.wiley.com/doi/...
).

In Brazil, only two antimicrobials for treating infections in aquatic animals are regulated (SINDAN, 2021SINDAN- Compêndio de produtos veterinários, 2021. Available from: <Available from: https://sidac.org.br >. Accessed: Feb. 3, 2022.
https://sidac.org.br...
). According to the normative instruction number 26 declared by the Ministry of Agriculture, Livestock and Supply (MAPA) on July 9, 2009, the use of beta-lactams, tetracyclines, sulfonamides, quinolones, and amphenicols as additives for enhancing animal performance or as animal food preservatives is prohibited (BRASIL, 2009BRASIL. Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Instrução Normativa n° 26 de 09 de julho de 2009. Regulamento Técnico para fabricação, o controle de qualidade, a comercialização e o emprego de produtos antimicrobianos de uso veterinário. Brasília, 2009.). The indiscriminate use of antibiotics in fish farming has favored the development of resistance genes through selective pressure and is one of the main factors responsible for the development and spread of multidrug-resistant bacteria (MUZIASARI et al., 2016MUZIASARI, W. I. et al. Aquaculture changes the profile of antibiotic resistance and mobile genetic element associated genes in Baltic Sea sediments. FEMS Microbiology Ecology, v.92, 2016. Available from: <Available from: https://doi.org/10.1093/femsec/fiw052 >. Accessed: Dec. 20, 2022. doi: 10.1093/femsec/fiw052.
https://doi.org/10.1093/femsec/fiw052...
).

To reduce the microbial load that can contaminate food, the industry uses sanitizers, which are defined as substances that contain one or more active ingredients with biocidal activity against harmful microorganisms (ROZMAN et al., 2021ROZMAN, U. et al. Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review. Microorganisms, v.9, n.12, p.2550, 2021. Available from: <Available from: https://www.mdpi.com/2076-2607/9/12/2550 >. Accessed: Apr. 18, 2022. doi: 10.3390/microorganisms9122550.
https://www.mdpi.com/2076-2607/9/12/2550...
) at safe levels, are not harmful to health, and are intended for use on surfaces, objects, and environments (KUAYE, 2017KUAYE, A. Y. Limpeza e sanitização na indústria de alimentos. Rio de Janeiro:Atheneu, 2017.). Chlorinated compounds, iodinated compounds, quaternary ammonium compounds, and peracetic acid are among the main groups of sanitizers used in the food industry (ANDRADE, 2008ANDRADE, N. J. Higiene na indústria de alimentos: avaliação e controle da adesão e formação de biofilmes bacterianos. São Paulo: Varela, 2008. 206p.; KUAYE, 2017KUAYE, A. Y. Limpeza e sanitização na indústria de alimentos. Rio de Janeiro:Atheneu, 2017.).

The resistance of A. hydrophila to antimicrobials and the main sanitizers used in the food industry makes this microorganism a target of study and has stimulated the search for better performing sanitizers. It is likely that fish sold in the retail environment in Brazil are contaminated with A. hydrophila,considering the non-application of good handling and sanitation practices in an adequate manner. In view of this, the study determined the resistance of retail fish-borne A. hydrophila isolates to 24 common antibiotics and five main sanitizers used in the food industry.

MATERIALS AND METHODS:

Samples

In this study, 19 A. hydrophila isolates obtained from the Food Microbiology Laboratory of the Federal Institute of Education, Science and Technology of Mato Grosso (IFMT) Campus Cuiabá Bela Vista were used. The bacteria were from a previous study by SILVA (2023SILVA, A. A. et al. Aeromonas sp. in freshwater fish and antimicrobial resistance: emerging pathogen. Ciência Rural, v.53, n.7, 2023. Available from: <Available from: https://doi.org/10.1590/0103-8478cr20220088 >. Accessed: Mar. 01, 2023. doi: 10.1590/0103-8478cr20220088.
https://doi.org/10.1590/0103-8478cr20220...
), having being isolated from samples of the Amazonian Pintado (Pseudoplatystoma fasciatum × Leiarius marmoratus), tambacu (Colossoma macropomum × Piaractus mesopotamicus), and tambatinga (Colossoma macropomum×Piaractus brachypomus) acquired from a supermarket, fair, and fish market in the city of Cuiabá, Mato Grosso, Brazil. The bacterial isolates cultured on tilted trypticase soy agar (TSA) in test tubes were stored at 4 °C refrigeration until the time of this study. The cultures were recultured daily for maintenance of the strains according to the method described by SILVA et al. (2017)SILVA, N. et al. Manual de métodos de análise microbiológica de alimentos e água. 5ed. São Paulo: Blucher, p.560, 2017..

Molecular characterization of the A. hydrophila isolates

Young colonies of A. hydrophilaon TSA were suspended in sterile water and boiled for 10 min in a dry bath (thermoblock) according to the methods described by PARK et al. (2021PARK, S. M. et al. Pathogenicity and seasonal variation of Aeromonas hydrophila isolated from seafood and ready-to-eat sushi in South Korea. Food Research International, v.147, 2021. Available from: <Available from: https://doi.org/10.1016/j.foodres.2021.110484 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.foodres.2021.110484.
https://doi.org/10.1016/j.foodres.2021.1...
) and LAU et al. (2020LAU, T. T. V. et al. Isolation, molecular characterization and antimicrobial susceptibility of Aeromonas spp. obtained from Tiger Grouper (Epinephelusfuscoguttatus) and Marble Goby (Oxyeleotrismarmoratus) fish in Sabah, Malaysia. Aquaculture Research, 2020. Available from: <Available from: https://doi-org.ez1.periodicos.capes.gov.br/10.1111/are.14739 >. Accessed: Apr. 18, 2022. doi: 10.1111/are.14739.
https://doi-org.ez1.periodicos.capes.gov...
). Then, each suspension was centrifuged at 24,104 × g for 5 min, following which the supernatant containing total genomic DNA was collected and quantified using a NanoDrop spectrophotometer. An aliquot of the extracted DNA was used for molecular identification of the isolate and the remaining was stored at -20 °C.

Molecular identification was performed using the polymerase chain reaction (PCR) technique. The 16S rRNA gene was targeted using 625 bp species-specific forward (5′-GAAAGGTTGATGCCTAATACGTA-3′) and reverse (5′-CGTGCTGGCAACAAAGGACAG-3′) primers (EL-GHAREEB et al., 2019EL-GHAREEB, H. M. et al. Occurrence, molecular characterization and antimicrobial resistance of pathogenic Aeromonas Hydrophila from retail fish. Alexandria Journal of Veterinary Sciences, v.62, n.1, p.172-181, 2019. Available from: <Available from: https://www.researchgate.net/publication/332273236 >. Accessed: Apr. 18, 2022. doi: 10.21608/zvjz.2015.29375.
https://www.researchgate.net/publication...
; PARK et al., 2021PARK, S. M. et al. Pathogenicity and seasonal variation of Aeromonas hydrophila isolated from seafood and ready-to-eat sushi in South Korea. Food Research International, v.147, 2021. Available from: <Available from: https://doi.org/10.1016/j.foodres.2021.110484 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.foodres.2021.110484.
https://doi.org/10.1016/j.foodres.2021.1...
). The conventional PCR mixture consisted of 3 μL of genomic DNA (50-150 ng) and 5 μL of 5× FIREPol Master Mix Ready To Load - 250 rxn (12.5 mM, composed of magnesium chloride, DNA Taq polymerase, reaction equilibration buffer, and sufficient dinucleotides for gene amplification; Solis BioDyne), 0.5 μL of each primerat 10 μM (Synthesis Biotechnology), and sterile water for making up the final volume to 25 μL.

According to the method described by EL-GHAREEB et al. (2019EL-GHAREEB, H. M. et al. Occurrence, molecular characterization and antimicrobial resistance of pathogenic Aeromonas Hydrophila from retail fish. Alexandria Journal of Veterinary Sciences, v.62, n.1, p.172-181, 2019. Available from: <Available from: https://www.researchgate.net/publication/332273236 >. Accessed: Apr. 18, 2022. doi: 10.21608/zvjz.2015.29375.
https://www.researchgate.net/publication...
), the following PCR program was used: denaturation at 95 °C for 5 min; 35 cycles of denaturation at 95 °C for 30 s, hybridization of primers at 50 °C for 40 s, and extension at 72 °C for 1.5 min; and a final extension at 72 °C for 5 min. After electrophoresis of the amplified products on a 1.5% agarose gel (100 V, 30 min), the bands were visualized using a UV LTB-HE transilluminator (Loccus Biotechnology). For the standard positive control bands, a commercial 100 bp DNA ladder (Sinapse Inc.) with fragments of known molecular weights was used.

Antimicrobial susceptibility testing

Antimicrobial susceptibility testing of the A. hydrophila isolates was performed using the agar diffusion method according to the technique described by BAUER et al. (1966BAUER, A. W. et al. Antibiotic susceptibility testing by a standardized single disk method. American Journal of Clinical Pathology, v.45, p.493-496, 1966. Available from: <Available from: http://doi:10.1093/ajcp/45.4_ts.493 >. Accessed: Apr. 17, 2022. doi: 10.1093/ajcp/45.4_ts.493.
http://doi:10.1093/ajcp/45.4_ts.493...
), where the bacterial colonies were inoculated into Mueller-Hinton agar and overlaid atop a disc impregnated with the specific antibiotic (Laborclin). In total, the following 24 commercial antibiotics previously defined by the Clinical and Laboratory Standards Institute (CLSI, 2020CLSI. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Eighteenth Informational Supplement. CLSI. Publication, 2020.) and scientific literature (HAFEZ et al., 2018HAFEZ, A. E. et al. Prevalence, antibiogram and molecular characterization of Aeromonas hydrophila isolated from frozen fish marketed in Egypt. Slovenian Veterinary Research, v.55, p.445-454, 2018. Available from: <Available from: https://doi.org/10.26873/SVR-671-2018 >.Accessed: Apr. 15, 2022. doi: 10.26873/SVR-671-2018.
https://doi.org/10.26873/SVR-671-2018...
; RAMADAN et al., 2018RAMADAN, H. et al. Aeromonas hydrophila from marketed mullet (Mugilcephalus) in Egypt: PCR characterization of b- lactam resistance and virulence genes. Journal of Applied Microbiology, v.124, p.1629-1637, 2018. Available from: <Available from: https://doi.org/10.1111/jam.13734 >. Accessed: Apr. 17, 2022. doi: 10.1111/jam.13734.
https://doi.org/10.1111/jam.13734...
; GUFE et al., 2019GUFE, C. et al. Antimicrobial profiling of bacteria isolated from fish sold at informal market in Mufakose, Zimbabwe. International Journal of Microbiology, 2019. Available from:<Available from:https://doi.org/10.1155/2019/8759636 >.Accessed: Apr. 18, 2022. doi: 10.1155/2019/8759636.
https://doi.org/10.1155/2019/8759636...
; ROGES et al., 2020ROGES, E. M. et al. Virulence-associated genes and antimicrobial resistance of Aeromonas hydrophila isolates from animal, food, and human sources in Brazil. BioMed Research International, 2020. Available from: <Available from: https://doi.org/10.1155/2020/1052607 >. Accessed: Apr. 10, 2022. doi: 10.1155/2020/1052607.
https://doi.org/10.1155/2020/1052607...
) were tested: combination beta-lactams (ampicillin/sulbactam, 10 µg), aminoglycosides (amikacin, 30 µg; streptomycin, 10 µg), beta-lactams (amoxicillin, 10 µg; ampicillin, 2 µg), 1st generation cephalosporins (cephalothin, 30 µg), 2nd generation cephalosporins (cefoxitin, 30 µg; cefuroxime, 30 µg), 3rd generation cephalosporins (cefotaxime, 30 µg; ceftazidime, 30 µg; ceftriaxone, 30 µg), 4th generation cephalosporins (cefepime, 30 µg), phenicols (chloramphenicol, 30 µg), sulfonamides/inhibitors of folic acid metabolism (sulfazotrim, 25 µg), lipopeptides (polymyxin B, 300 IU), macrolides (erythromycin, 15 µg), nitrofurans (nitrofurantoin, 300 µg), penicillins and beta-lactamase inhibitors (piperacillin/tazobactam, 30/6 µg; penicillin G, 10 U), quinolones/fluoroquinolones (nalidixic acid, 30 µg; ciprofloxacin, 5 µg; levofloxacin, 5 µg), and tetracyclines (doxycycline, 30 µg; tetracycline, 30 µg). Antimicrobial resistance was classified as sensitive, intermediate, or resistant on the basis of the zone of inhibition (in millimeters) measured on each disc and the standard table for Enterobacteriaceae(CLSI, 2020CLSI. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Eighteenth Informational Supplement. CLSI. Publication, 2020.), which establishes the cut-off points of the inhibition halos.

For the antimicrobial susceptibility test, each bacterial suspension was first prepared to a turbidity of 0.5 (McFarland scale) in sterile 0.85% saline solution. Then, the suspension was inoculated into Mueller-Hinton agar medium, and the mixture was overlaid atop each antibiotic-impregnated disc. Incubation was carried out in a bacteriological oven at 35 °C (±2 °C) for 18 - 24 h.

After 18-24 h growth of the isolate, the diameter (in millimeters) of the inhibition halo was measured using a meter stick and interpreted using the standard table for classification of the level of strain sensitivity to the antimicrobial tested. As no halo was formed for some of the antibiotics tested (ampicillin, cephalothin, erythromycin, penicillin G, and polymyxin B), they could only be classified as resistant.

Sanitizer susceptibility testing

The susceptibility profile of A. hydrophila to sanitizers was determined using the method described by WANJA et al. (2020WANJA, D. W. et al. Antibiotic and Disinfectant Susceptibility Patterns of Bacteria Isolated from Farmed Fish in Kirinyaga County, Kenya. International Journal Microbiology, 2020. Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414343/ >. Accessed: Apr. 18, 2022. doi: 10.1155/2020/8897338.
https://www.ncbi.nlm.nih.gov/pmc/article...
), with modifications. The following commercial sanitizers commonly applied in the food industry were tested: 300 mg∙L-1peraceticacid, 70% alcohol, 700 mg∙L-1 quaternary ammonium, 200 mg∙L-1 sodium hypochlorite, and 0.3% hydrogen peroxide (YUAN et al., 2020YUAN, L. et al. Recent advances in understanding the control of disinfectant-resistant biofilms by hurdle technology in the food industry. Critical Reviews in Food Science and Nutrition, 2020. Available from:<Available from:https://doi.org/10.1080/10408398.2020.1809345 >. Accessed: Sep. 16, 2022. doi:10.10408398.2020.1809345.1080.
https://doi.org/10.1080/10408398.2020.18...
). These were diluted according to the manufacturers’ instructions for use and the concentrations cited in the literature. The same steps and conditions applied to the agar diffusion test for antibiotics was applied to that for the sanitizers, starting with the prior preparation of the sanitizer dilutions and of the bacterial suspensions to a turbidity of 0.5 in sterile 0.85% saline solution. After inoculation of the bacterial suspension into Mueller-Hinton agar, the mixture was overlaid atop sterile monodiscs (Laborclin) soaked in the respective sanitizers. Following 18-24 h incubation, the inhibition halos were measured. Results were interpreted according to the criteria described by KUAYE (2017KUAYE, A. Y. Limpeza e sanitização na indústria de alimentos. Rio de Janeiro:Atheneu, 2017.), and the isolates with no halo formation were considered resistant to the sanitizer applied.

Statistical analysis

The data of this study were tabulated, typed, and saved on an electronic spreadsheet. Statistical analysis was conducted using R Core Team software(FOX & WEISBERG, 2020FOX, J.; WEISBERG, S. CAR: Companion to Applied Regression. [R package], 2020. Available from: <Available from: https://cran.rproject.org/package=car >.Accessed: Apr. 17, 2022.
https://cran.rproject.org/package=car...
; LENTH, 2020LENTH, R. EMMEANS: Estimated Marginal Means, aka Least-Squares Means. [R package], 2020. Available from: <Available from: https://cran.rproject.org/package=emmeans >. Accessed: Apr. 20, 2022.
https://cran.rproject.org/package=emmean...
; R CORE 15 TEAM, 2020R CORE TEAM. R: A Language and environment for statistical computing. (Version 4.0) [Computer software], 2020. Available from: <Available from: https://cran.r-project.org >. Accessed: Apr. 17, 2022. (R packages retrieved from MRAN snapshot 2020-08-24).
https://cran.r-project.org...
; JAMOVI PROJECT, 2021THE JAMOVI PROJECT. Jamovi. (Version 1.6) [Computer Software], 2021. Available from: <Available from: https://www.jamovi.org >. Accessed: Sep. 16, 2022.
https://www.jamovi.org...
), where descriptive analysis was performed. Because of the non-normality of the data (Shapiro-Wilktest), the Wilcoxon non-parametric test was used.

RESULTS AND DISCUSSION:

All 19 A. hydrophila isolates were confirmed to the species level by means of the molecular PCR technique, using species-specific primersdirected against the 16S rRNA gene. High levels of A. hydrophila resistance to various antimicrobial agents were found in this study (Table 1), especially to ampicillin (> 89%, n = 17), cephalothin (> 84%, n = 16), ampicillin sulbactam (> 78%, n = 15), penicillin G (> 73%, n = 14), and cefuroxime and erythromycin (> 52%, n = 10), all of which are not regulated for the treatment of aquatic animal infections (SINDAN, 2021SINDAN- Compêndio de produtos veterinários, 2021. Available from: <Available from: https://sidac.org.br >. Accessed: Feb. 3, 2022.
https://sidac.org.br...
). In contrast, the levels of resistance to piperacillin tazobactam(< 6%, n = 1) and tetracycline (< 10.5%, n = 2) were low.

Table 1
Antimicrobial susceptibility of Aeromona shydrophila isolates (n = 19) recovered from retail fish.

Multidrug resistance, characterized as resistance to at least one antibiotic in three or more classes (JEONG et al., 2007JEONG, H. Y. et al. Molecular Epidemiology of Community-Associated Antimicrobial-Resistant Staphylococcus aureus in Seoul, Korea (2003): Pervasiveness of Multidrug-Resistant SCC mec Type II Methicillin-Resistant S. aureus. Microbial Drug Resistance, v.13, p.178-185, 2007. Available from: <Available from: https://doi.org/10.1089/mdr.2007.709 >. Accessed: Apr. 18, 2022. doi: 10.1089/mdr.2007.709.
https://doi.org/10.1089/mdr.2007.709...
), was evidenced in this study, as the A. hydrophila isolates recovered from retail fish showed resistance to at least one antibiotic in all the classes investigated. This phenomenon may be attributed to the indiscriminate use of antimicrobials in aquaculture, genetic mutations, or the horizontal dissemination of resistance genes (LAU et al., 2020LAU, T. T. V. et al. Isolation, molecular characterization and antimicrobial susceptibility of Aeromonas spp. obtained from Tiger Grouper (Epinephelusfuscoguttatus) and Marble Goby (Oxyeleotrismarmoratus) fish in Sabah, Malaysia. Aquaculture Research, 2020. Available from: <Available from: https://doi-org.ez1.periodicos.capes.gov.br/10.1111/are.14739 >. Accessed: Apr. 18, 2022. doi: 10.1111/are.14739.
https://doi-org.ez1.periodicos.capes.gov...
).

The high resistance to beta-lactams (ampicillin, cephalothin, ampicillin sulbactam, penicillin G, and cefuroxime) is in accordance with the known intrinsic resistance of Aeromonas species to this class of antibiotics. Production of the chromosomal enzyme beta-lactamase is recognized as a common feature among species of genus Aeromonas and contributes to their resistance to beta-lactams (ROSSOLINI et al., 1996ROSSOLINI, G. M. et al. The Aeromonas Metallo-β-Lactamases: Genetics, Enzymology, and Contribution to Drug Resistance. Microbial Drug Resistance,v.2, n.2, p.245-252, 1996. Available from: <Available from: https://doi.org/10.1089/mdr.1996.2.245 >. Accessed: Apr. 17, 2022. doi: 10.1089/mdr.1996.2.245.
https://doi.org/10.1089/mdr.1996.2.245...
). This intrinsic resistance is related to the chemical instability of the beta-lactam ring in the antibiotic structure, making the drugs susceptible to hydrolysis through bacterial beta-lactamase activity (ZDANOWICZ et al., 2020ZDANOWICZ, M. et al. Abundance and antibiotic resistance of Aeromonas isolated from the water of three carp ponds. Veterinary Research Communications, v.44, p.9-18, 2020. Available from: <Available from: https://doi.org/10.1007/s11259-020-09768-x >. Accessed: Apr. 18, 2022. doi: 10.1007/s11259-020-09768-x
https://doi.org/10.1007/s11259-020-09768...
).

In the isolation of Aeromonas, the use of ampicillin is recommended (MCMAHON & WILSON, 2001MCMAHON, M. A. S.; WILSON, I. G. The occurrence of enteric pathogens and Aeromonas species in organic vegetables. International Journal of Food Microbiology, v.70, n.1, p.155-162, 2001.) owing to the intrinsic resistance of the species to this beta-lactam antibiotic, which facilitates selection of the bacterium among other bacteria present in the medium that are inhibited by the antimicrobial agent. The findings of this study confirm this common characteristic of the Aeromonas species and is in agreement with the findings of other studies (DAHDOUH et al., 2016DAHDOUH, B. et al. Molecular characterization, antimicrobial susceptibility and salt tolerance of Aeromonashydrophila from fresh, brackish and marine fishes. Alexandria Journal of Veterinary Sciences, v.48, n.2, p.46-53, 2016. Available from: <Available from: http://www.alexjvs.com >. Accessed: Apr. 18, 2022. doi: 10.5455/ajvs.208107.
http://www.alexjvs.com...
; RAMADAN et al., 2018RAMADAN, H. et al. Aeromonas hydrophila from marketed mullet (Mugilcephalus) in Egypt: PCR characterization of b- lactam resistance and virulence genes. Journal of Applied Microbiology, v.124, p.1629-1637, 2018. Available from: <Available from: https://doi.org/10.1111/jam.13734 >. Accessed: Apr. 17, 2022. doi: 10.1111/jam.13734.
https://doi.org/10.1111/jam.13734...
; WU et al., 2019WU, C. J. et al. Aeromonas Isolates from Fish and Patients in Tainan City, Taiwan: Genotypic and Phenotypic Characteristics. Applied and Environmental Microbiology, v.85, n.21, 2019. Available from: <Available from: https://doi.org/10.1128/AEM.01360-19 >. Accessed: Apr. 18, 2022. doi: 10.1128/AEM.01360-19.
https://doi.org/10.1128/AEM.01360-19...
).

Results obtained regarding A. hydrophila resistance to the cephalosporins were similar to those of other studies (RAMADAN et al., 2018RAMADAN, H. et al. Aeromonas hydrophila from marketed mullet (Mugilcephalus) in Egypt: PCR characterization of b- lactam resistance and virulence genes. Journal of Applied Microbiology, v.124, p.1629-1637, 2018. Available from: <Available from: https://doi.org/10.1111/jam.13734 >. Accessed: Apr. 17, 2022. doi: 10.1111/jam.13734.
https://doi.org/10.1111/jam.13734...
; SANTOS et al., 2019SANTOS, E. J. R. et al. Hygienic-sanitary quality of tambaqui (Colossomamacropomum) sold in the city of São Luís - MA. Ciência Animal Brasileira, v.20, n.1-12, 2019. Available from: <Available from: https://doi.org/10.1590/1809-6891v20e-46537 >. Accessed: Apr. 18, 2022. doi: 10.1590/1809-6891v20e-46537.
https://doi.org/10.1590/1809-6891v20e-46...
; ZAHER et al., 2021ZAHER, H. A. et al. Prevalence and Antibiogram of Vibrio parahaemolyticus and Aeromonashydrophila in the Flesh of Nile Tilapia, with Special Reference to Their Virulence Genes Detected Using Multiplex PCR Technique. Antibiotics, v.10, 2021. Available from: <Available from: https://doi.org/10.3390/antibiotics10060654 >. Accessed: Apr. 18, 2022. doi: 10.3390/antibiotics10060654.
https://doi.org/10.3390/antibiotics10060...
). This drug resistance is mainly due to the degradation activities of extended-spectrum beta-lactamases and ampC (a chromosomal cephalosporinase), the main beta-lactamases involved in bacterial resistance to cephalosporins, which may be inherent to the bacteria or even acquired, resulting in the inability of the antibiotics to reach their site of action (MACHADO et al., 2019MACHADO, O. V. O. et al. Antimicrobianos: revisão geral para graduandos e generalistas. Fortaleza: Ed. Unichristus, 2019. 4.620 Kb; E-book - pdf. 452p.).

The resistance and multidrug resistance profiles of Aeromonas species from freshwater fish are characterized mainly by the residues from the aquaculture practice itself, where resistance genes are spread throughout the environment and resistance determinants are transferred from terrestrial animals to bacteria and human pathogens (CABELO, 2006CABELO, F. C. Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment. Environmental Microbiology, v.8, n.7, p. 1137-1144, 2006. Available from: <Available from: https://doi.org/10.1111/j.1462-2920.2006.01054.x >. Accessed: Apr. 17, 2022. doi:10.1111/j.1462-2920.2006.01054.x.
https://doi.org/10.1111/j.1462-2920.2006...
; FAUZI et al., 2021FAUZI, N. N. F. N. M. et al. Prevalence, antibiotic susceptibility, and presence of drug resistance genes in Aeromonas spp. isolated from freshwater fish in Kelantan and Terengganu states, Malaysia. Veterinary World, v.14, 2021. Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8448652/ >. Accessed: Apr. 18, 2022. doi: 10.14202/vetworld.2021.2064-2072.
https://www.ncbi.nlm.nih.gov/pmc/article...
; NHINH et al., 2021NHINH, D.T. et al. Prevalence, virulence Gene Distribution and Alarming the Multidrug Resistance of Aeromonas hydrophila Associated with Disease Outbreaks in Freshwater Aquaculture. Antibiotics,v.10, n.5, p.532, 2021. Available from: <Available from: https://doi.org/10.3390/antibiotics10050532 >. Accessed: Apr. 18, 2022. doi:10.3390/antibiotics10050532.
https://doi.org/10.3390/antibiotics10050...
). The indiscriminate use of antimicrobials in aquatic animals and the consequent contamination of the environment are primarily responsible for the spread of resistant strains in fish (KIMERA et al., 2020KIMERA, Z. I. et al. Antimicrobial use and resistance in food-producing animals and the environment: an African perspective. Antimicrobial Resistance & Infection Control, v.9, n.37, 2020. Available from: <Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7053060/ >. Accessed: Apr. 18, 2022. doi: 10.1186/s13756-020-0697-x.
https://www.ncbi.nlm.nih.gov/pmc/article...
). The high level of antibiotic resistance in A. hydrophila reported in this study suggested that the indiscriminate use of antimicrobials in humans and animals has contributed to the development and dissemination of resistance genes along the food chain. It also indicated that unregulated antimicrobials are being misused and overused in fish farming, given that only oxytetracycline and florfenicol are approved for use in Brazil (CARVALHO & SANTOS, 2016CARVALHO, I. T.; SANTOS, L. Antibiotics in the aquatic environments: A review of the European scenario. Environment International, 2016. Available from: <Available from: http://doi.org/10.1016/j.envint.2016.06.025 >. Accessed: Aug. 30, 2022. doi: 10.1016/j.envint.2016.06.025.
http://doi.org/10.1016/j.envint.2016.06....
; BUENO et al., 2017BUENO, I. et al. Impacto de fontes pontuais em genes de resistência a antibióticos no ambiente natural: uma revisão sistemática das evidências. Animal Health Research Reviews, v.18, p.112-127, 2017. Available from: <Available from: https://doi.org/10.1017/S146625231700007X >. Accessed: Mar. 14, 2022. doi: 10.1017/S146625231700007X.
https://doi.org/10.1017/S146625231700007...
; SIDAN, 2021).

It is worth noting that some authors have suggested that the beta-lactamase gene is present in the diverse microbiota in the aquatic environments where these fish are raised, representing a serious problem in view of the high enzymatic potential to hydrolyze beta-lactam antibiotics (ZDANOWICZ et al., 2020ZDANOWICZ, M. et al. Abundance and antibiotic resistance of Aeromonas isolated from the water of three carp ponds. Veterinary Research Communications, v.44, p.9-18, 2020. Available from: <Available from: https://doi.org/10.1007/s11259-020-09768-x >. Accessed: Apr. 18, 2022. doi: 10.1007/s11259-020-09768-x
https://doi.org/10.1007/s11259-020-09768...
). This poses a threat to human health and potentiates the risk of occurrence of antimicrobial resistance (EMA, 2014EMA- European Medicines Agency. Answers to the requests for scientific advice on the impact on public health and animal health of the use of antibiotics in animals. European Medicines Agency, 2014. Available from: <Available from: https://www.ema.europa.eu/ >. Accessed: Apr. 20, 2022.
https://www.ema.europa.eu/...
; STRATEV & ODEYEMI, 2016STRATEV, D.; ODEYEMI, O. A. Antimicrobial resistence of Aeromonas hydrophila isolated from different food soucers: A mini-review. Journal of Infection and Public Health, v.9, n.5, p.535-544, 2016. Available from: <Available from: https://doi.org/10.1016/j.jiph.2015.10.006 >. Accessed: Apr. 17, 2022. doi: 10.1016/j.jiph.2015.10.006.
https://doi.org/10.1016/j.jiph.2015.10.0...
).

With regard to the resistance of the A. hydrophila isolates to the main industrial sanitizers at the concentrations tested in this study (Table 2), the bacteria showed the lowest percentage (15.78%) of resistance to 3% hydrogen peroxide, which was the most effective of the tested sanitizers. However, it is important to note that the classification of sanitizer sensitivity is complex. The resistance rate obtained in this study can be justified by the fact that A. hydrophila produces catalase, an important cell-detoxifying enzyme that is responsible for converting hydrogen peroxide (a toxic metabolite) into water and oxygen molecules (KUAYE, 2017KUAYE, A. Y. Limpeza e sanitização na indústria de alimentos. Rio de Janeiro:Atheneu, 2017.). As a strong oxidant, hydrogen peroxide is commonly used as a bactericide and sporicide, with low toxicity and residual effect (GERMANO & GERMANO, 2015GERMANO, P. M. L.; GERMANO, M. I. S. Higiene e vigilância sanitária de alimentos:qualidade das matérias-primas, doenças transmitidas por alimentos, treinamento de recursos humanos. 5 ed. Barueri: Manole, p. 1020, 2015.). Its sanitizing effectiveness against A. hydrophila was evidenced in this study for more than 80% of the isolates.

Table 2
Radius (in millimeters) of the zone of inhibition of various sanitizers tested against Aeromonas hydrophila isolates.

In contrast, a high rate of resistance to 200 mg∙L-1 sodium hypochlorite was observed in more than 90% of the isolates. Chlorine compounds, including sodium hypochlorite, are generally among the most commonly used sanitizers in the food industry. These chemicals have good sanitizing efficacy at low concentrations, are not affected by water hardness, and have high effectiveness against a wide spectrum of bacteria, notwithstanding the fact that they are the cheapest among most sanitizers (ANDRADE, 2008ANDRADE, N. J. Higiene na indústria de alimentos: avaliação e controle da adesão e formação de biofilmes bacterianos. São Paulo: Varela, 2008. 206p.; KUAYE, 2017KUAYE, A. Y. Limpeza e sanitização na indústria de alimentos. Rio de Janeiro:Atheneu, 2017.). However, at the recommended concentration, this active ingredient was not sufficient for inhibiting the growth of the A. hydrophila isolates in this study.

The chemical sanitizers based on peracetic acid and quaternary ammonium, as well as alcohol, were ineffective against the A. hydrophila isolates at the concentrations tested. More than 80% of the isolates were resistant to 300 mg∙L-1peracetic acid and 70% alcohol, whereas more than 60% were resistant to 700 mg∙L-1 quaternary ammonium.The resistance to disinfectants is related to several cellular mechanisms - internal and external to the bacterial cell - that had resulted from phenotypic and genotypic adaptations (ROZMAN et al, 2021ROZMAN, U. et al. Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review. Microorganisms, v.9, n.12, p.2550, 2021. Available from: <Available from: https://www.mdpi.com/2076-2607/9/12/2550 >. Accessed: Apr. 18, 2022. doi: 10.3390/microorganisms9122550.
https://www.mdpi.com/2076-2607/9/12/2550...
).

Although, there are several aspects related to the mechanism of bacterial resistance to sanitizers, the most common ones are the restricted permeability of the bacterial cell wall, enzymatic degradation, expression of efflux systems, biofilm formation, and changes in the target sites (LAMBERT, 2002LAMBERT, P. Cellular impermeability and uptake of biocides and antibiotics in Gram-positive bacteria and micobacteria. Journal of Applied Microbiology, v.92, p.46S-54S, 2002. Available from: <Available from: https://doi.org/10.1046/j.1365-2672.92.5s1.7.x >. Accessed: Sep. 2, 2022. doi: 10.1046/j.1365-2672.92.5s1.7.x.
https://doi.org/10.1046/j.1365-2672.92.5...
; CHAPMAN, 2003CHAPMAN, J. S. Biocide resistance mechanisms. International Biodeterioration & Biodegradation. v.51, p.133-138, 2003. Available from: <Available from: https://doi.org/10.1016/S0964-8305(02)00097-5 >. Accessed: Sep. 2, 2022. doi: 10.1016/S0964-8305(02)00097-5.
https://doi.org/10.1016/S0964-8305(02)00...
). Efflux pumps comprise the main pathways of resistance to sanitizers, and the exposure of microorganisms to inhibitory and subinhibitory concentrations of antimicrobials contributes to the development of resistance (WEBBER & PIDDOCK, 2003WEBBER, M.; PIDDOCK, L. The importance of efflux pumps in bacterial antibiotic resistance. Journal Antimicrobial Chemother. v.51, p.9-11, 2003. Available from: <Available from: https://doi.org/10.1093/jac/dkg050 >. Accessed: Sep. 2, 2022. doi: 10.1093/jac/dkg050.
https://doi.org/10.1093/jac/dkg050...
; GNANADHAS et al., 2013GNANADHAS, D. P. et al. Biocides-resistance, cross-resistance mechanisms and assessment. Expert Opin. Investig. Drugs, v.22, p.191-206, 2013. Available from: <Available from: https://doi.org/10.1517/13543784.2013.748035 >. Accessed: Sep. 2, 2022. doi: 10.1517/13543784.2013.748035.
https://doi.org/10.1517/13543784.2013.74...
).

In nature, gram-negative bacteria tend to be more resistant than gram-positive bacteria to antimicrobials owing to the complexity of their cell wall. According to MAILLARD (2002MAILLARD, J. Y. Bacterial target sites for biocide action. Journal of Applied Microbiology, v.92, p.16-27, 2002. Available from: <Available from: https://europepmc.org/article/med/12000609 >. Accessed: Apr. 18, 2022. doi: 10.1046/j.1365-2672.92.5s1.3.x.
https://europepmc.org/article/med/120006...
), the biocidal activity of sanitizers can vary significantly among different types of microorganisms and even among different strains of the same species.

Despite its importance, bacterial resistance to sanitizing agents has not been treated with interest and due attention by the academic community. The indiscriminate use of sanitizing agents can significantly decrease their effectiveness against clinically important microorganisms (ROZMAN et al., 2021ROZMAN, U. et al. Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review. Microorganisms, v.9, n.12, p.2550, 2021. Available from: <Available from: https://www.mdpi.com/2076-2607/9/12/2550 >. Accessed: Apr. 18, 2022. doi: 10.3390/microorganisms9122550.
https://www.mdpi.com/2076-2607/9/12/2550...
). This outcome poses a serious threat to food safety, especially coupled with the fact that foodborne outbreaks can become highly recurrent if sanitizer resistance becomes established, especially in the food industry (CARLIE et al., 2020CARLIE, S. M. et al. Molecular basis of bacterial disinfectant resistance. Drug Resistance Updates, v.48, 2020. Available from: <Available from: https://doi.org/10.1016/j.drup.2019.100672 >. Accessed: Apr. 18, 2022. doi: 10.1016/j.drup.2019.100672.
https://doi.org/10.1016/j.drup.2019.1006...
). Therefore, results of this study suggest the need for further research on the factors that affect the performance of sanitizing agents in the fish processing environment, aiming the ultimate goals of selecting the most efficient sanitizer to be applied in the sanitization process and corroborating the safety of this food type.

CONCLUSION:

The A. hydrophila isolates in this study showed multiple resistance to 24 antimicrobials from several classes, especially to ampicillin, cephalothin, ampicillin sulbactam, penicillin, erythromycin, and cefuroxime. In contrast, piperacillin tazobactam and tetracycline were the antimicrobials with the highest percentages of susceptible strains. As determined from the resistance index, 200 mg∙L-1 sodium hypochlorite was the least effective sanitizer against the isolates, whereas 3% hydrogen peroxide was the most effective.

ACKNOWLEDGMENTS

The authors thank the Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso (IFMT) for funding the research [Call No. 001/2020 DPG/PROPES/IFMT]. And was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil - Finance code 001.

REFERENCES

  • CR-2022-0256.R2

Edited by

Editors: Rudi Weiblen (0000-0002-1737-9817) Juliana Cargnelutti Felipetto (0000-0002-3160-3643)

Publication Dates

  • Publication in this collection
    26 May 2023
  • Date of issue
    2023

History

  • Received
    02 May 2022
  • Accepted
    31 Jan 2023
  • Reviewed
    18 Apr 2023
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