Biofilm formation of Salmonella species isolated from fresh cabbage and spinach

Abstract

ABSTRACT: The aim of the study was to isolate Salmonella from fresh cabbage and spinach vegetables, determine antimicrobial resistance and biofilm formation of the isolates. Spinach and cabbage farm vegetables were found to harbour Salmonella. A total of eighty-two Salmonella isolates were recovered from both vegetables and subjected to antimicrobial reactions. Salmonella isolate showed sensitivity against the aminoglycoside and quinolones. Isolates from cabbage showed ≥ 80% susceptibility to nalidixic acid and ciprofloxacin and an average of 72% susceptibility was exhibited against gentamicin and ofloxacin. Also, isolates from spinach vegetable demonstrated excellent sensitivity against chloramphenicol (94%), nalidixic acid (90%) and ofloxacin (82%). Variable resistant patterns was observed for tetracycline (58%: 47%), ampicillin (55.5%: 31.4%), erythromycin (58.1%: 62.7%), streptomycin (64.5%: 76.5%), cephalothin (35.5%: 39.2%) against isolates from cabbage and spinach respectively. The assessment of biofilm formation by Salmonella on microtitre plate showed that all Salmonella isolates were able to form biofilms. Isolates from cabbage were mainly strong producer 15(48.3%), while 11(35.5%) of the isolates were moderate producers and 6(16.1%) weak producer. On the other hand, 28(54.9%) of Salmonella isolates from spinach vegetable were moderate producer, 12(23.5%) weak producer and 11(21.5%) strong producer. The finding of this study shows that cabbage and spinach is potential host for the transmission of Salmonella to humans or other animals. The ability of the isolates to form biofilm reveals the potential of the isolates to persist on the vegetable and the pathogenic status of the isolates as well as ability to resist antimicrobial chemotherapy. © JASEM