Multidrug-resistance and biofilm formation profiles of Salmonella spp. isolated from raw chicken meat

Abstract

Available data showed that the recovery of multidrug-resistant and biofilm-producing Salmonella spp. from chicken meat is still scanty in Nigeria. Consequently, this study aimed to characterize the probable multidrug-resistant and biofilm producing Salmonella spp. prevalent in chicken meat vended in southern Nigerian markets. About 240 randomly sampled chilled raw chicken meats were collected from open markets in Delta, Edo, Ekiti and Ondo States, and then were analysed for detecting the presence of Salmonella spp.; using rinse centrifugation-plating technique, serological examination and 16S rRNA gene sequencing. The confirmed Salmonella isolates were tested for multidrug-resistance and biofilm formation using Kirby Bauer disc diffusion test and tissue culture plates, respectively. Out of 229 presumptively examined Salmonella isolates, 52 isolates were confirmed as Salmonella spp., while 46 isolates were recorded as multidrug-resistant. The main serotypes recovered were; S. enterica subsp. enterica serovar Typhimurium (35/52; 67.31%), and S. enterica subsp. enterica serovar Enteritidis (17/52; 32.69%). Biofilm characterization of the recovered Salmonella isolates were; strong (OD > 0.240), 6 (11.5 %); moderate (0.120-0.240), 13 (25.0 %); weak (OD < 0.120), 19 (36.5 %), and non-biofilm producers (OD < 0.120), 14 (26.9 %). This study showed that multidrug-resistant and biofilm-producing Salmonella spp. were prevalent in raw chicken meat; vended within southern Nigerian open markets. Thus, there is an urgent need for relevant regulatory agencies to enforce consumer's safety.