Thermophile Endospores have Responsive Exosporium for Attachment

Recently studies examining the colonization of Clostridial pathogens on agar and human tissue culture cells, demonstrated that (C. sporogenes ATCC 3584, C. difficile ATCC 43594 [patient isolate], C. difficile ATCC 9689 [non-clinical], C. clostridioforme [patient isolate]) bacterial spores (endospores) of the genus Clostridia have an outer membrane that becomes responsive at activation and exhibits extensions of the exosporial membrane that facilitate and maintain spore attachment to a nutritive substrate during germination and initial outgrowth of the newly developed bacterial cell. Therefore this attachment phenomenon plays an important role in insuring bacterial colonization of a surface and the initial stages of the infective process. To see if other non-clinical members of this genus also have this ability to attach to a substrate or food-source during spore germination, and how this attachment process in environmental thermophiles compares to the clinical paradigm (in relation to time sequence, exosporial membrane structure, type of attachment structures, composition of the membrane etc.), sediment samples were collected in sterile transport containers at 4 geothermal sites at Yellowstone National Park in Wyoming.

Characterization and Behavior of Salmonella javiana During Manufacture of Mozzarella-type Cheese1

A patient isolate of Salmonella javiana implicated in an outbreak of salmonellosis in Minnesota was characterized and used to examine its response to Mozzarella manufacturing conditions. The strain possessed biochemical-metabolic activities typical of Salmonella species. Growth was observed in 6.5% NaCl Trypticase Soy Broth (TSB) but not in 12% NaCl TSB. This S. javiana strain was resistant to two antibiotics, penicillin G and erythromycin. Pasteurization trials indicated the strain did not survive pasteurization and that pasteurization affected a log reduction of greater than 9 cycles. Mozzarella-type cheese was manufactured from milk inoculated with S. javiana at levels of 1 × 104 and 1 × 106 per ml milk. Manufacturing process was monitored by following pH, titratable acidity, and temperature. Survival of S. javiana was monitored using traditional enrichment procedures and direct plating procedures. S. javiana survived and grew through the acid-ripening phase, but temperatures attained in cheese mass during stretching and molding (60°C, 140°F) killed all Salmonella present. No subsequent process steps were found positive for Salmonella.