Prevalence of Listeria spp. in Fresh Shrimp from Local Markets and Its Susceptibility to Antibiotics

Abstract

This study aimed to determine the prevalence of Listeria spp. in fresh shrimp in Bogor, Indonesia, and to determine the antibiotic susceptibility patterns of isolated Listeria spp. A quantitative descriptive approach was employed. A total of 25 samples of fresh shrimp were obtained from randomly selected traditional markets (n = 18) and modern markets (n = 7). The results revealed that 14 samples (56.0%) were positive for Listeria spp. Among them, 11 (78.6%) and 3 (21.4%) were selected from traditional markets and modern markets, respectively. Thirty-six isolates, which upon biochemical characterization included 1 (2.8%) Listeria innocua, 26 (72.2%) Listeria grayi, 1 (2.8%) Listeria welshimeri, and 8 (22.2%) Listeria-like strains, were identified. The most common isolates were L. grayi, while the least common were L. innocua and L. welshimeri. The disk diffusion assay determined the susceptibility of the 36 strains to 10 commercial antibiotics. In general, 100% of the 36 isolated Listeria spp. were resistant to amoxicillin and nebacetin, and almost 100% were susceptible to chloramphenicol. However, antibiotic multiple resistance (AMR) was observed, with all Listeria strains resistant to more than two antibiotics. No isolate was resistant to only one antibiotic. The present study provides the first baseline data on the prevalence of Listeria spp. in fresh shrimp in Indonesia and the susceptibility of these isolates to antibiotics.