Multiplex polymerase chain reaction (PCR) and reversed passive latex agglutination (RPLA) identification of Staphylococcus aureus enterotoxigenic strains

Staphylococcus aureus is one of the main pathogens causing food poisoning worldwide. Many S. aureus strains produce one or more of enterotoxins (SEs). SEs are recognized agents of intoxication staphylococcal food-borne syndrome but may be also involved in other types of infections with sequelae of shock in humans and animals. The purpose of this study was to detect the staphylococcal SE genes (sea to see) and to reveal toxin in vitro production on S. aureus isolates

Assessment of enteral bacteria

The disruption of intestinal barrier leads to the penetration of noxious luminal compounds into the gut wall, causing further damage. This unit describes the assessment of enteric bacteria translocation into the intestinal wall of rats, an established method for the evaluation of bowel damage to the mucosal epithelial barrier. The Basic Protocol provided in the present unit describes collection and preparation of small intestine sample, performing of sample serial dilutions for bacterial culture, performing of the culture of aerobic and anaerobic bacteria on petri dishes, incubation of the cultured plates, and counting of bacterial colonies. The Support Protocols describes the procedures for the preparation of petri dishes for the culture, using different employable media for aerobes or anaerobes. The Alternate Protocol describes the use of the “inclusion method,” suitable for the culture of anaerobic bacteria

MOLECULAR TOXINOTYPING OF CLOSTRIDIUM PERFRINGENS AND CLOSTRIDIUM DIFFICILE CATTLE AND SWINE ISOLATES BY PCR ASSAYS

Clostridium perfringens and C. difficile are common causes of enteritis and enterotoxaemia in humans and domestic and wild animals. The purpose of this study was to investigate the enterotoxigenic profile of cattle and swine isolates by PCRs. Methods One hundred and nineteen bovine (faecal and intestine) samples and 110 swine faeces were analyzed by culture assay. All C. perfringens isolates were screened for the characterization of the toxinotype. C. difficile strains were PCR-tested for the presence of tcdA/tcdB and cdtA/cdtB genes. Results Overall, 53 bovine samples tested positive: 37 for C. perfringens and 16 for C. difficile. In two C. perfringens-positive diarrhoeic samples, C. difficile was also isolated. All C. perfringens isolates were type A; C. difficile strains resulted tcdA/tcdB and cdtA/cdtB-negative. Sixty-five swine resulted positive: 17 for C. perfringens and 38 for C. difficile. All C. perfringens isolates were type A; eight were also cpb2-positive. All C. difficile strains resulted tcdA/tcdB and cdtA/cdtB-negative. In one C. perfringens cpb2-positive diarrhoeic sample C. difficile (tcdA/tcdB and cdtA/cdtB-positive) was also isolated. Clinical Significance Understanding the diversity of toxigenic strains may lead to a greater understanding of the pathogenesis in cattle and swine and help in the development of effective intervention methods for controlling clostridial disease outbreaks