Occurrence and antimicrobial resistance of bacteria in retail market spices

Abstract

This study aimed to evaluate the microbiological quality and the transmission of multidrug-resistant bacteria in different spices sold in town fairs (local food markets) in the municipalities of Recôncavo Baiano. Samples of black pepper, oregano, and cinnamon were collected over a period of six months and investigated for coliforms at 45 °C, Staphylococcus spp., Staphylococcus aureus, Bacillus spp., Bacillus cereus, Escherichia coli and Salmonella spp. The contamination in the black pepper samples (log 4.66 CFU g-1) was higher (P>0.05), than those of cinnamon (log 2.55 CFU g-1) and oregano (log 2.49 CFU g-1), particularly for B. cereus. E. coli (89%) and Salmonella spp. (67%) were isolated only from black pepper. B. cereus and S. aureus showed greater resistance to β-lactams (penicillin, oxacillin, and cefepime), with approximately 40% of the strains with a multiple antimicrobial resistance (MAR) index of 0.33 (i.e., resistant to three antimicrobials). E. coli was more resistant to ampicillin and Salmonella spp. to nalidixic acid, ampicillin, and ceftriaxone. Salmonella spp. had a MAR index ranging from 0.16 to 0.91 (i.e, resistant to up to 11 antimicrobials), and E. coli to up to 0.58 (i.e., resistant to 7 antimicrobials). In conclusion, the spices sold in the town fairs of Recôncavo Baiano are of low microbiological quality, with the presence of pathogens, of which some display high resistance to antimicrobials that are commonly used for treating foodborne illnesses.

Antibiotic resistance pattern of the allochthonous bacteria isolated from commercially available spices

“…The lack of or the low microbial load of different spices could be attributed to the bioactive components with antimicrobial properties (Costa et al, 2020;Thanh et al, 2018). Bata-Vidács et al, (2018) determining the microbiological quality of seventy-one spice paprika samples from 10 countries (Hungary, China, Serbia, Spain, India, Bulgaria, Brazil, Peru, Kenya, Thailand, and unknown place) concluded that the dominant microorganisms in spice paprika samples are influenced by different factors such as the climate of cultivation.…”

“…The multiple antibiotic resistance (MAR) index of the screened bacterial strains was calculated with the help of the following formula: MAR index =x/y, where (x) is the number of antibiotics, to which the bacteria species was resistant, and (y) refers to the number of tested antibiotics defined for multidrug resistance (Costa et al, 2020).…”

“…This possibility may be attributed to the existing various critical points (vulnerabilities) of microbial contamination during plant cultivation and product supply chain (Alegbeleye et al, 2018;Székács et al, 2018). Even though the spices have low water activity, they could be harbored by diverse pathogenic and spoilage microorganisms (Costa et al, 2020;Melo González et al, 2017). As dried herb products, they may be contaminated by different molds too.Due to the high tolerance to dehydration stress, Salmonella species can survive longer in dry products such as spices.…”