Detection of enterotoxins genes in coagulase-negative staphylococci isolated from foods

Abstract

Staphylococcal food poisoning is caused by ingestion of enterotoxins preformed in the food contaminated essentially through human manipulation or raw material obtained from animals. Although coagulase-positive Staphylococcus aureus is the main agent responsible for food intoxication, some researches emphasise that coagulase-negative staphylococci (CNS) are able to produce staphylococcal enterotoxins and may be a potential cause of food poisoning. In the present study CNS were isolated from foods and the toxigenic capacity of the strains determined. A total of 88 food samples were analysed and 22.7% were positive for CNS strains. Staphylococcal counts ranged from 3.0 x 10 2 to 1.4 x 10 6 CFU/g or mL of food examined. S. epidermidis predominated among the isolates (40%). Further isolates included S. xylosus (20%), S. warneri (20%), S. saccharolyticus (15%), and S. hominis (5%). Four isolates were positive for enterotoxin genes, as detected by polymerase chain reaction, with sea being the predominant gene. Although no enterotoxin production was detected by the reverse passive latex agglutination method, the data showed that the toxigenic capacity of CNS should not be ignored, requiring investigation of this group of microorganisms in food.

Influence of a native strain of Staphylococcus xylosus on the microbiological, physicochemical and sensorial characteristics on milano salami type

“…Staphylococcal food poisoning occurs by ingestion of the pre-formed enterotoxins in consequence of human manipulation or raw material derived from the contaminated animals. Cunha et al, (2006) evaluated 88 food samples and 4 CNS isolates by PCR and found them positives for the genes that codified the enterotoxins but none enterotoxin production was detected by RPLA method. Very little, however, is known about the growth of CNS in food.…”

Microbial contamination in industrial tofu

“…FLEMING et al (2010), studying bovine cheese, reported higher SCN counts in 50% of those samples where counts of SCP were also above the limits of legislation. The SCN may also hold enterotoxin genes and many reports of food poisoning from SCN through ingestion of raw cow's milk have been made (CARMO et al, 2002;CUNHA et al, 2006;PODKOWIK et al, 2013;MELLO et al, 2014). Despite the possible ability of SCN to produce enterotoxins, most reports of staphylococcal poisoning have been predominantly related to the presence of SCP.…”

Isolation, Identification and Antibiogram of Coagulase Negative Staphylococcus (CoNS) Isolated from Various Clinical Samples at a Tertiary Care Teaching Hospital, Jaipur, India

“…Infected tissues of host support large populations of staphylococci and in some situations they persist for long periods. (Cunha et al, 2006) Coagulase-negative staphylococci (CoNS) are divided into more than 40 species (David et al, 2012) and more than a dozen subspecies, of which approximately half have been associated with human infections. (Valle et al, 1999) Today, Coagulase-negative staphylococci (CoNS), as typical opportunists, represent one of the major nosocomial pathogens, having a substantial impact on human life and health and accounting for 27% to 32% and 50% of such infections among adult and paediatric patients, respectively.…”