Abstract
Introduction. Salmonella bacteria belong to the Gram-negative Enterobacteriaceae family. They are motile, relatively anaerobic, and lactose-negative colony-forming bacteria that ferment glucose and lack cytochrome oxidase. Infections from Salmonella bacteria such as typhoid, paratyphoid, and salmonellosis can pose a threat to both human health and life. Typhoid is a disease caused by the most prominent serological variant of the Salmonella genus, Salmonella Typhi, and it spreads only amongst humans who also serve as the only reservoir/sink of this infection.
Aim. To determine the rate of persons testing positive for carrying Salmonella bacilli relative to the number of healthy people tested in the Lesser Poland Province during 2017–2022. To establish the most frequently identified serotypes of Salmonella in healthy people residing in the Lesser Poland Province during 2017–2022.
Material and methods. The laboratory test material to determine Salmonella carriers among healthy people were three stool samples collected by study subjects once a day for three consecutive days by means of sampling into test tubes suitable for transport in accordance with laboratory instructions. Each stool sample delivered to the laboratory was inoculated directly onto a solid MacConkey agar medium. After incubating the samples in MacConkey’s agar at 36 °C ± 1 °C for 18-24 hours, further diagnostic procedures were performed on isolated colonies characteristic of the Salmonella genus, i.e., lactose-negative, colorless. and transparent.
Results. The average rate of healthy people diagnosed with Salmonella bacilli living in the Lesser Poland Province was 0.25% in 2017–2022. This was a constant for each year. There were 35 different Salmonella serotypes identified in healthy people from the Lesser Poland Province in the years 2017–2022. The most frequent serotype detected was Salmonella Enteritidis, accounting for 71 % of all the detected serotypes in Salmonella carriers. The second and third most commonly found serotypes were Salmonella Infantis (9.9%) and Salmonella Typhimurium (4.6%), respectively. Other Salmonella serotypes were identified in individual cases and together accounted for 14.1% of all the detected serotypes. Only one case of Salmonella typhoid was identified, s. Paratyphi B, in 2022, during the 2017–2022 period.
Conclusions: The observed increase in food safety and a reduced number of cases in Poland are a direct results of the Polish State Sanitary Inspection (SANEPID) supervision that includes microbiological food testing and testing healthy people to detect Salmonella carriers. It should be noted that typhoid strains may appear due to travelling without prior and proper preparation, (i.e. vaccination, avoiding risky situations and observing tropical hygiene) to countries where Salmonella disease is endemic,, as well as in the result of an influx of immigrants.