Bacterial succession and reduced antibiotic resistance gene burden in rabbit meat under low-oxygen modified atmosphere packaging.

Optimal gas compositions of O2, N2, and CO2 in modified atmosphere packaging (MAP) have been shown to inhibit spoilage in meat and meat products effectively. This study investigated the impact of three different MAP methods (MAPa: 70% O2 / 30% CO2; MAPb: 70% N2 / 30% CO2; MAPc: 20% O2 / 60% N2 / 20% CO2) and air packaging (CK) on the physicochemical characteristics, spoilage dynamics, and bacterial succession of rabbit meat during 8 days of chilled storage. The MAPc meat consistently had the lowest TVB-N and TBARS values, and consequently exhibited the slowest spoilage progress among all groups. 16S rRNA sequencing revealed dramatic shifts in the microbial community from Shigella-, Bacteroides- and Lactococcus-dominant rabbit meat before 4 days of storage to Brochothrix- and Psychrobacter-dominated spoilage communities as storage time progressed. Notably, Psychrobacter was markedly inhibited in MAPc (11.03%) compared to CK (42.45%) at day 8. Metagenomic analysis conducted on MAPc and CK samples identified 183 ARGs, mostly tetracycline resistance genes. Moreover, Tet(L), CfxA3, Tet(Q), ANT(4')-lb, and Msr(D) were identified as the predominant ARGs in rabbit meat, while MAPc significantly reduced the relative abundance of AcrB, Tet(M), MacB, Sul2, APH(6)-ld, Tet(S), and Msr(E). Most of the ARGs were primarily harbored by Psychrobacter, Pseudomonas, and Brochothrix thermosphacta. Importantly, at the near-spoiled stage, ARG abundance increased in CK group but decreased in MAPc samples, suggesting that low-O₂ MAP treatment reduces ARG levels. Overall, low-O₂ MAP (MAPc) represents a promising preservation strategy that extends the shelf life of rabbit meat while reducing ARG abundance.