Microbiological and parasitological quality of Lactuca sativa L. sold at farmers’ markets in Goiânia, Goiás

Title : Microbiological and parasitological quality of Lactuca sativa L. sold at farmers’ markets in Goiânia, Goiás

Abstract:

Background: Fresh leafy vegetables eaten raw can carry foodborne bacteria and intestinal parasites when contamination occurs during cultivation, transport, handling or sale. Farmers’ markets are an important source of fresh produce in Brazil, but sanitary conditions vary considerably between points of sale.
Objective: To evaluate the microbiological and parasitological quality of Lactuca sativa L. sold at farmers’ markets in Goiânia, Goiás, Brazil, and to characterize potential infectious hazards relevant to food safety and public health.
Methods: Forty curly lettuce samples were collected from five farmers’ markets between August 2023 and February 2024. Total and thermotolerant coliforms were determined by the most probable number (MPN) method, and mesophilic aerobic bacteria were counted as colony-forming units (CFU). Bacterial strains were isolated and identified. Parasitological analysis used washing, sedimentation, centrifugation, Lugol staining and optical microscopy.
Results: Total coliform counts ranged from 2.18 × 101 to 1.52 × 106 MPN/g, thermotolerant coliforms from 1.80 × 101 to 2.25 × 106 MPN/g, and mesophilic aerobic bacteria from 1.88 × 101 to 7.80 × 106 CFU/g. Among 43 bacterial isolates, Escherichia coli accounted for 41.86%, Klebsiella pneumoniae 16.28%, Enterobacter sp. 13.95%, Serratia sp. 11.62%, Pseudomonas sp. 6.98%, Shigella sp. 4.65% and Salmonella sp. 4.65%. Parasites were detected in 30% of samples (Entamoeba sp., Giardia sp. and nematode larvae), and mixed parasitic contamination was observed in 20% of samples.
Conclusion: Lettuce sold at the evaluated farmers’ markets showed relevant microbiological and parasitological contamination, including organisms associated with fecal contamination and potential foodborne hazards. These findings reinforce the importance of sanitary surveillance, health education and good hygiene practices throughout the food production and commercialization chain.
Keywords: Foodborne diseases; Lactuca sativa; food safety; Escherichia coli; intestinal parasites; farmers’ markets

Biography:

My name is Adevaldes Neto. I am 27 years old, Catholic, and a native of Brazil, where I still live. I hold a bachelor’s degree in Civil Engineering, which I completed at the end of 2023, and then worked in the construction industry for one year. I am currently a third-semester medical student at Centro Universitário de Goiatuba (UniCerrado). I have also completed several courses to strengthen my skills with artificial intelligence tools, particularly Claude.ai.
One of the main reasons I chose to study medicine is my deep passion for medical physiology and its role in people’s physical and mental well-being. I am especially fascinated by the endocrine system and by how the body’s systems work together. Exercise physiology, sports medicine, clinical nutrition, and related fields are my true calling, and I intend to keep growing in these areas so I can become an excellent physician dedicated to improving people’s quality of life.