Enterotoxin Production in Two-Culture Media by Yersinia enterocolitica Isolated from Sausages, Porcine Ceca and Tongues in San Luis, Argentina

1991 ◽  
Vol 54 (1) ◽  
pp. 47-49
Author(s):  
ANA MARIA S. DE GUZMAN ◽  
NORMA B. B. DE PEDERIVA ◽  
LUIS S. MAYORGA ◽  
BLAS MICALIZZI
Keyword(s):  
Body Weight ◽  
Yersinia Enterocolitica ◽  
Culture Media ◽  
Infant Mouse ◽  
San Luis ◽  
Heat Stable ◽  
Enterotoxin Production ◽  
Casamino Acids

Twenty-six strains of Yersinia enterocolitica isolated from fresh sausages, bovine tongues, and porcine ceca and tongues were evaluated for the production of heat-stable enterotoxin (ST, infant mouse test) in trypticase soy broth (TSB) and casamino acids broth (CAB). The gut weight/body weight ratios obtained with the two media were similar. Sixteen strains produced ST in both media; nine strains did not. Strain 23 produced ST in CAB but not in TSB.

Isolation of Toxigenic Yersinia enterocolitica from Retail Pork Products

1980 ◽  
Vol 43 (5) ◽  
pp. 360-365 ◽  
Author(s):  
D. A. SCHIEMANN
Keyword(s):  
Yersinia Enterocolitica ◽  
Ileal Loop ◽  
Infant Mouse ◽  
Pork Products ◽  
Heat Stable

Five of 69 (7%) processed and 63 of 128 (49%) raw retail pork products contained Yersinia enterocolitica. Thirty-two of 80 (40%) isolates were serotypable, with serotypes 0:3 and 0:5 occurring most frequently. All except one isolate of serotype 0:3 came from fresh pork tongues. Twenty-five isolates (32%) produced a heat-stable enterotoxin detected by the infant mouse and rabbit ileal loop assays. Live cultures in the rabbit ileal loop produced no response. Most of the serotype 0:3 (92%) and 0:5 (90%) isolates were mouse-positive, while most rhamnose-positive (89%) and citrate-positive (96%) isolates were mouse-negative.

The Heat-Stable Enterotoxin(s) of Yersinia enterocolitica in Foods

1984 ◽  
Author(s):  
Stephen L. Taylor ◽  
Michael P. Doyle ◽  
Alison R. Behling
Keyword(s):  
Yersinia Enterocolitica ◽  
Heat Stable

A modified bioassay for heat-stable Escherichia coli enterotoxin

1977 ◽  
Vol 23 (3) ◽  
pp. 331-336 ◽  
Author(s):  
S. Stavric ◽  
D. Jeffrey
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Incubation Time ◽  
Evans Blue ◽  
Room Temperature ◽  
Blue Dye ◽  
Evans Blue Dye ◽  
Heat Stable ◽  
Stomach Distention ◽  
Time Required

Infant mice were injected orally with preparations containing Escherichia coli heat-stable enterotoxin (ST) and Evans blue dye, and incubated at 22 °C. With enterotoxin-positive samples, the stomach was distended and contained essentially all of the dye. With enterotoxin-negative samples, the stomach remained normal in size and the dye passed freely into the intestines. The time required to obtain the maximum ratio of gut weight to body weight varied from 30 to 90 min and was dependent upon the concentration of enterotoxin. Heat-labile enterotoxin (LT) had no effect during this period.Based on these findings, the mouse incubation time was reduced from 4 h to 90 min, and the heating of test samples was retained only for confirmation of ST. The location of the dye and stomach distention served as an indicator of positive responses to ST. Incubation of the mice at room temperature (22 °C) was found satisfactory.

DETECTION AND SURVIVAL OF YERSINIA ENTEROCOLITICA IN GOAT CHEESE PRODUCED IN SAN LUIS, ARGENTINA

2010 ◽  
Vol 30 (4) ◽  
pp. 982-995 ◽  
Author(s):  
VALERIA LAZARTE OTERO ◽  
CECILIA LUCERO ESTRADA ◽  
GABRIELA ISABEL FAVIER ◽  
LIDIA VELÁZQUEZ ◽  
MARÍA ESTHER ESCUDERO ◽  
...  
Keyword(s):  
Yersinia Enterocolitica ◽  
San Luis ◽  
Goat Cheese

An overview of Yersinia enterocolitica and related species in samples of different origin from San Luis, Argentina

2020 ◽  
Vol 86 ◽  
pp. 103345 ◽  
Author(s):  
Cecilia Lucero-Estrada ◽  
Gabriela Isabel Favier ◽  
María Esther Escudero
Keyword(s):  
Yersinia Enterocolitica ◽  
Related Species ◽  
San Luis ◽  
Different Origin

THE PRODUCTION BY BACILLUS THURINGIENSIS BERLINER OF A HEAT-STABLE SUBSTANCE TOXIC FOR INSECTS

1959 ◽  
Vol 5 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Ellicott McConnell ◽  
A. Glenn Richards
Keyword(s):  
Bacillus Thuringiensis ◽  
Inclusion Bodies ◽  
Galleria Mellonella ◽  
Culture Media ◽  
Water Soluble ◽  
Broth Culture ◽  
Toxic Principle ◽  
Heat Stable

Bacillus thuringiensis Berliner produces in vitro a heat-stable, dialyzable substance which is toxic for insects when injected. The same or a similar substance is produced in vivo. The toxic principle is of unknown composition. It is heat-stable, water-soluble, dialyzable, and resistant to low temperatures. It is probably neither a protein nor a lipid. Clearly it is distinct from the heat-labile inclusion bodies and from lecithinase. Growth-curve studies showed that the heat-stable toxin appeared in liver broth cultures during the active growth phase, prior to the formation of spores or inclusion bodies. An attempt to produce the toxic principle from culture media in the absence of bacteria was unsuccessful from sterile inocula both from in vivo and in vitro sources. The LD50 for larvae of Galleria mellonella injected with autoclaved supernatant from a 10-day-old liver broth culture of B. thuringiensis was determined to be 0.00036 ml per larva or 0.002 ml per gram of larvae. Approximately the same level of toxicity was found for another caterpillar, a fly larva, and cockroaches. After larvae of Galleria or Pyrausla have been dead for more than 2 days from infection with B. thuringiensis the bacillus could no longer be recovered. A sublethal amount of the heat-stable toxin injected into old larvae of Galleria delayed emergence of the adults by 30 to 40%. The non-pathogenic Bacillus cereus was found to produce a similar-acting, heat-stable toxin under the same conditions that one is produced by B. thuringiensis.

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