Antibiotic Resistance Profiles and ARG Detection from Isolated Bacteria in a Culture-Dependent Study at the Codfish Industry Level

The antibiotic resistance phenomenon horizontally involves numerous bacteria cultured from fresh or processed seafood matrix microbiomes. In this study, the identified bacteria from food-producing processes and industrial environments were screened for phenotypic and genotypic resistance determinants. A total of 684 bacterial strains [537 from processed codfish (Gadus morhua and Gadus macrocephalus) products as salted and seasoned and soaked and 147 from environmental samples] were isolated. Antibiotic susceptibility tests showed resistance against tetracycline, oxacillin, and clindamycin in the Staphylococcus genus (both from food and environmental samples) and against beta-lactams (cefotaxime, carbapenems, etc.) and nitrofurans (nitrofurantoin) from E. coli and Salmonella enterica serovar. Enteritidis isolates. One-thousand and ten genetic determinants-tetracycline tetC (25.17%), tetK (21.06%), tetL (11.70%), clindamycin ermC (17.23%), ermB (7.60%), linezolid cfr (8.22%), optrA (3.62%), poxtA (2.05%), and oxacillin mecA (17.37%)-were amplified from Gram-positive resistant and phenotypically susceptible bacteria. Concerning Gram-negative bacteria, the beta-lactam-resistant genes (bla_TEM, bla_CIT, bla_CTX-M, bla_IMP, bla_KPC, bla_OXA-48-like) represented 57.30% of the amplified ARGs. This study found high antibiotic resistance genes in circulation in the fish food industry chain from the macro- to microenvironment. The obtained data confirmed the diffusion of the "antibiotic resistance phenomenon" and its repercussions on the One-health and food-producing systems.

Shelf Life and Safety of Vacuum Packed HPP-Treated Soaked Cod Fillets: Effects of Salt Content and Multilayer Plastic Film

High microbiological quality standards, food safety, and environmental sustainability represent crucial topics in food production chains. For this reason, fish industries, which import salted and seasoned fish products from supplier countries, i.e., Norway, Denmark, USA (Alaska State), etc., have tried to reduce the salt content of each carton during transportation (reducing carbon emissions and the weight of major quantities of transported fish). In the present study, 360 differently processed fish fillet samples, belonging to the species Gadus macrocephalus caught in FAO zone 67, were microbiologically and chemically screened. This study aimed to provide original data concerning the applicability of sustainable solutions investigating the combined effects of salt content reduction combined with new recyclable multilayer plastic film packaging (vacuum skin packaging with two different oxygen transmission rate values). The microbiological results showed no substantial changes comparing the two differently salted products, highlighting their high hygienic characteristics which were also observed in their chemical analysis. The shelf life evolutions (comparing the two different studied plastic films) highlighted that, after 35 days from HPP treatments, bacterial loads gained high values, over 6 log cfu/g. This study highlights that, compared to the currently used plastic films, the results of the new and sustainable multilayer plastic films show that they can provide safe food matrices in combination with HPP technologies. Therefore, this preliminary investigation brings closer attention to alternative and environmentally sustainable production systems with their designs based on the multidisciplinary approach of food production systems.