Safety Evaluation Of Sjenica Cheese With Regard To Coagulase-Positive Staphylococci And Antibiotic Resistance Of Lactic Acid Bacteria And Staphylococci

Abstract

Sjenica cheese is an artisanal cheese stored in brine, traditionally produced from raw sheep's milk in the southern part of Serbia -Sjenica Pester plateau.The aim of this study was to perform the safety evaluation of Sjenica cheese. As one of the safety criteria we considered the number of coagulase positive staphylococci and their enterotoxigenic potential. Antibiotic susceptibility/resistance patterns of autochthonous lactic acid bacteria and coagulase-positive staphylococci isolated from Sjenica cheese was also investigated.During the monitoring period of the cheese-making process, coagulase positive staphylococci did not reach the value of 10 5 cfu/g. Among coagulase positive staphylococci, 12 (46,15%) isolates showed enterotoxigenic potential and were identifi ed as Staphylococcus intermedius (11 isolates) and Staphylococcus aureus (1 isolate). Vancomycin resistance was the most prevalent phenotypic resistance profi le in coagulase positive staphylococci.Lactococci present the most dominant population among lactic acid bacteria. The most prevalent resistance phenotype in lactococci was resistance to streptomycin (83.33%), ampicillin and penicillin (70.83%); lactobacilli were characterized by resistance to vancomycin (62.5%) and tetracycline (54.17%), while resistance to streptomycin (82.46%) was the most prevalent phenotypic profi le in enterococci.All coagulase positive staphylococci and lactic acid bacteria isolates that showed resistance to tetracycline on disc diffusion and E-test, were tested for the presence of ribosomal protection proteins, tet(M) and tet(K) genes. All isolates were positive for ribosomal protection proteins genes; 14 (60.87%) isolates showed tet(M) gene presence, while 2 lactobacilli isolates revealed the presence of tet(K) gene.

Microbiological Safety and Physicochemical Quality Parameters of Goat and Sheep Cheese From Herzegovina

“…lactic acid bacteria. When examining Sjenica autochthonous cheese in brine in southwestern Serbia, produced from raw sheep's milk, during the monitored period of cheese production, the number of coagulase-positive staphylococci did not reach the value of 105 CFU/g (Bulajić et al, 2015), which coincides with the results of our study. Also, Zarate et al (1997) investigated Staphylococcus aureus in goat cheese from Tenerife (Spain), produced from raw milk, without the addition of starter, consumed fresh (within 2-3 days) or after ripening for 60 days.…”

Detection and enterotoxin production of Staphylococcus aureus isolates in artisanal cheese made from raw milk

“…This work represents the first study of risk assessment of acid-set cheese related to CoPS in our region. Out of a total 50 samples, CoPS were isolated from 36 samples of cheese, or 72% of all samples, which is in compliance with the findings of other authors, who tested other sorts of traditional cheeses made from raw milk in our region (Bulaji c et al, 2015;Goli c et al, 2015). The European Commission (2005) suggested that raw milk products should not contain a high bacterial concentration (10 5 -10 6 CFU g À1 or mL À1 ), in order to prevent production of staphylococcal enterotoxins during the manufacturing process.…”

Occurrence of antibiotic resistance genes in the fecal DNA of healthy omnivores, ovo-lacto vegetarians and vegans

“…and (10 of 13) 1601098 coagulase-positive cocci, notoriously carrying this determinant. In support of this hypothesis, tet(K) + strains ascribed to E. coli, Salmonella and S. aureus have recently been isolated from eggs intended for human consumption [34]; analogously, tet(K) + lactobacilli [35,36] and coagulase-positive staphylococci [36] have recently been isolated from different cheeses. With regards to this latter food matrix, a recent research aimed at identifying and detecting tetracycline and erythromycin resistance genes in Spanish and Italian retail cheeses revealed that traditional Italian cheeses might effectively act as a reservoir for many antibiotic resistance determinants, including tet(K) [37].…”