Incidence, evaluation of detection and identification methods, and antimicrobial resistance of Aeromonas spp. in ready-to-eat foods

This study aimed to investigate the prevalence of Aeromonas spp. in ready-to-eat foods (temakis, cheeses and minimally processed fruits) and to characterize the virulence profile and antimicrobial resistance of the isolates. The species A. hydrophila, A. caviae and A. veronii were identified using polymerase chain reaction (PCR), which was later compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The performance of two isolation selective agars (starch-ampicillin agar-SAA and Aeromonas agar-AA) was also evaluated. Aeromonas spp. was isolated in 66.67 % (20/30) of temaki, 3.23 % (1/31) of fruits and none (0/30) of cheeses, observing high microorganism counts from <102 to 2.6 × 105 CFU/g. A. caviae (26.39 %) was the most prevalent species, followed by A. hydrophila (20.83 %) and A. veronii (8.34 %), and 44.44 % were classified as Aeromonas sp. The performance analysis between PCR and MALDI-TOF/MS for Aeromonas identification was not statistically significant, and the Kappa index showed moderate agreement (p < 0.01 and Kappa = 0.718). The SAA selective medium performed better than AA. We identified seventeen virulence profiles, and 59.72 % of the isolates had some of the genes studied. The aerA gene (47.2 %) was the most abundant, followed by act (41.7 %), hlyA and alt (38.9 %), and ast (18.1 %). A. hydrophila was the species most associated with these genes. The antimicrobial susceptibility test showed that 90 % of t...
Source: International Journal of Food Microbiology - Category: Food Science Authors: Source Type: research