Determination of Certain Microbiological Quality Characteristics of Ice Cream, Detection of Salmonella by Conventional and Immunomagnetic Separation Methods and Antibiotic Susceptibility of Salmonella spp. Isolates

This study aimed to evaluate certain microbiological quality characteristics, titration acidity and pH values, Staphylococcus aureus counts, presence of Salmonella spp. in ice cream by conventional and immunomagnetic separation (IMS) methods. Also, the antibiotic susceptibility of Salmonella spp. isolates was demonstrated by 10 different antibiotic disks. For this purpose, 55 ice cream samples were collected from markets and pastries and analyzed in terms of the specified parameters. The results showed that 3/55 ice cream samples were positive in terms of S. aureus, while 2/55 sample were found positive by the IMS method with respect to Salmonella. The Salmonella isolates were confirmed as 100% Salmonella spp. by the conventional methods and API 20E test kit. The carried out antibiotic susceptibility test results indicated that these two isolates showed susceptibility to ciprofloxacin, sulfamethoxazole/trimethoprim, chloramphenicol, nalidixic acid, trimethoprim and tetracycline at 100% level, while their resistance to streptomycin, ampicillin and kanamycin were at 100% level. Practical Applications Ice cream is a popular frozen dairy product made with milk, cream, water and other ingredients. The quality of ice cream is affected by some factors, including wide variety of ingredients, production practices, transportation, storage conditions and temperature fluctuations. Although the potentially hazardous pathogenic microorganisms are rarely encountered in ice cream due to unsuitable conditions, they can be contaminated by the various types of microorganisms. The use of sensitive and specific methods for the isolation and identification of pathogen microorganisms is very important. Immunomagnetic separation system has been used for the selective capture and concentration of Salmonella from various foods. On the contrary, the antibiotic susceptibility of pathogens has a critical importance for human health. For this reason, it is thought that determination of antibiotic susceptibility and resistance of isolated and identified Salmonella spp. is very important in terms of food safety and human health.