Isolation and identification of Enterobacteriaceae from traditional Serbian cheese and their physiological characteristics

Abstract

In this paper, the presence of enterobacteria in autochthonous cheese from Southeast Serbia (Sokobanja), made in the traditional way, was investigated. The samples from different households, was taken during the summer and the autumn. Chemical and physical characteristics of samples (water content, fat content, acidity, pH, and sodium chloride content) were examined. In the analyzed samples of cheese, four different genera of family Enterobacteriaceae (Klebsiella [65%],, and Enterobacter [5%]) were identified. The members of genus Klebsiella were Klebsiella oxytoca, Klebsiella pneumoniae, and Klebsiella ornithinolytica, while in the genus Escherichia only one species, Escherichia coli was identified. Besides, two species of the genus Serratia, Serratia odorifera and Serratia marcescens biogp 1, and one species of the genus Enterobacter, Enterobacter gergoviae, were identified. Biochemical characteristics, proteolytic and lipolytic activity, sensitivity to streptomycin, chloramphenicol, and tetracycline were, also, determined. According to the rapid latex agglutination test, of the four E. coli isolates, two isolates belong to serotype E. coli O157. Practical applicationsThe results of this study contribute to better understanding of unexplored microflora of cheese from Sokobanja. The isolated genera were Klebsiella sp., Escherichia sp., Enterobacter sp., and Serratia sp. with twenty identified species. It is well known that bacteria from family Enterobacteriaceae could affect organoleptic properties of cheese. Bacteria isolated from cheese from Sokobanja mostly did not manifest proteolytic and lipolytic activity. The most number of isolates were susceptible to tested antibiotics. Further researches may contribute to better understanding of interaction between enterobacteria and lactic acid bacteria in autochthonous cheeses.

Characterization of lactic acid bacteria isolated from traditionally made Serbian Cheese and evaluation of their antagonistic potential against Enterobacteriaceae

“…The processes of cheese-making, sampling, and the storage of cheese samples were described in detail in Mladenović, Muruzović, Zugić Petrović, Stefanović, and Comić (2017). The tested cheese was produced in countryside households around Sokobanja (Southeastern Serbia), in traditional way.…”

In vitro evaluation of antimicrobial potential and ability of biofilm formation of autochthonousLactobacillusspp. andLactococcusspp. isolated from traditionally made cheese from Southeastern Serbia

“…According to the results described in Mladenović et al (2018) and Muruzović et al (2018), all tested indicator stains demonstrated sensitivity to streptomycin and chloramphenicol. P. mirabilis ATCC 12,453 showed resistance to tetracycline (10 mm…”

“…For comparison, indicator stains were tested on the sensitivity to the antibiotic, and this method was described in detail Mladenović et al () and Muruzović et al ().…”

The influence of environmental factors on the planktonic growth and biofilm formation of Escherichia coli

“…E. coli ATCC 25922 was used as a positive control. The bacteria were previously isolated from Serbian cheese (Sokobanja region) and determined at the Laboratory for Microbiology at the Faculty of Science, University of Kragujevac (KGPMF) (MLADENOVIĆ et al, 2018). The collection of identified bacterial species was kept in a 20% glycerol/medium mixture at -80 °C.…”