THE EFFECT OF LYSOZYME ON THE APPARENT HEAT RESISTANCE OF NONPROTEOLYTIC TYPE B CLOSTRIDIUM BOTULINUM

1985 ◽  
Vol 7 (3) ◽  
pp. 145-154 ◽  
Author(s):  
VIRGINIA N. SCOTT ◽  
DANE T. BERNARD
Keyword(s):  
Heat Resistance ◽  
Clostridium Botulinum ◽  
Type B

Potential for Growth of Nonproteolytic Types of Clostridium botulinum in Pasteurized Restructured Meat Products: A Review1

1985 ◽  
Vol 48 (3) ◽  
pp. 265-276 ◽  
Author(s):  
J. SIMUNOVIC ◽  
J.L. OBLINGER ◽  
J.P. ADAMS
Keyword(s):  
Heat Resistance ◽  
Causative Agent ◽  
Clostridium Botulinum ◽  
Meat Products ◽  
Type B ◽  
The U.S ◽  
Restructured Meat

Type E and nonproteolytic type B strains of Clostridium botulinum can grow and produce toxin at temperatures below 5°C. Recent publications describing the greater heat resistance of nonproteolytic type B C. botulinum spores than type E spores are discussed in relation to suitable proess lethalities required for a safe pasteurized product. The incidences of botulism in Europe caused by nonproteolytic type B spores were compared to the lack of such incidences in the U.S. and to published procedures for isolating the causative agent for botulism. The incidence of C. botulinum spores in meat products in the U.S. also is reviewed.

Thermal Resistance of Nonproteolytic Type B and Type E Clostridium botulinum Spores in Phosphate Buffer and Turkey Slurry†

1995 ◽  
Vol 58 (7) ◽  
pp. 758-763 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
BRIAN S. EBLEN ◽  
BENNE S. MARMER ◽  
AARON C. WILLIAMS ◽  
SAMUEL A. PALUMBO ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Phosphate Buffer ◽  
Clostridium Botulinum ◽  
Thermal Processes ◽  
Type B ◽  
Concomitant Increase ◽  
Death Time ◽  
Thermal Death ◽  
D Values ◽  
Thermal Death Time

The heat resistance of nonproteolytic type B and type E Clostridium botulinum spores in phosphate buffer and turkey slurry was determined from 70 to 90°C. Thermal-death times were determined in vials heated using a water bath. Recovery of heat-injured spores was on reinforced clostridial medium (RCM) and tryptic soy agar (TSA) with and without added lysozyme (10 μg/ml). Decimal-reduction times (D-values) were determined by fitting a survival model to the data using a curve-fitting program. The apparent or measured heat resistance was maximum with RCM supplemented with lysozyme. The D-values at 80°C for type E spores in buffer ranged from 1.03 min for strain Whitefish to 4.51 min for strain Saratoga. The D-value for the most heat-resistant nonproteolytic type B strain KAP B5 in buffer was 4.31 min at 80°C. The z-values in buffer for all strains were very similar, ranging from 8.35 to 10.08°C.Turkey slurry offered protection to the spores with a concomitant increase in heat resistance. The D-values in turkey slurry ranged from 51.89 min at 70°C to 1.18min at 85°C for type E strain Alaska (z = 9.90°C) and from 32.53 min at 75°C to 0.80 min at 90°C for nonproteolytic type B strain KAP B5 (z = 9.43°C). Thermal-death-time values from this study will assist food processors to design thermal processes that ensure safety against nonproteolytic C. botulinum in cook/chill foods.

Heat Resistance of Spores of Non-Proteolytic Type B Clostridium botulinum

1982 ◽  
Vol 45 (10) ◽  
pp. 909-912 ◽  
Author(s):  
VIRGINIA N. SCOTT ◽  
DANE T. BERNARD
Keyword(s):  
Liquid Phase ◽  
Heat Resistance ◽  
Clostridium Botulinum ◽  
Beef Heart ◽  
Regression Analyses ◽  
Type B ◽  
Death Time ◽  
Thermal Death ◽  
Biphasic Medium ◽  
Thermal Death Time

The heat resistance of spores of non-proteolytic type B Clostridium botulinum was compared to that of type E and proteolytic type B spores. Spore suspensions were produced in a biphasic medium consisting of beef heart agar overlaid with a liquid phase containing trypticase, peptone, glucose, starch and cysteine. Thermal death time curves were established for seven strains heated in phosphate buffer. In general, spore suspensions of non-proteolytic type B strains had greater thermal resistance than type E strains. Decimal reduction times at 82.2°C, established by linear regression analyses of data, ranged from 1.49 to 32.3 min, but the higher heat resistances were not obtained consistently, even with different spore suspensions of the same strain. None of the spore suspensions of non-proteolytic, type B C. botulinum demonstrated heat resistance comparable to that of the proteolytic type B spores.

Influence of Sodium Chloride on Thermal Inactivation and Recovery of Nonproteolytic Clostridium botulinum Type B Strain KAP B5 Spores†

1995 ◽  
Vol 58 (7) ◽  
pp. 813-816 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
BRIAN S. EBLEN
Keyword(s):  
Sodium Chloride ◽  
Heat Resistance ◽  
Clostridium Botulinum ◽  
Thermal Inactivation ◽  
Type B ◽  
Botulinum Type ◽  
Survival And Growth ◽  
Reduced Salt ◽  
D Values ◽  
Recovery Medium

Demand for minimally processed refrigerated foods with reduced salt levels has stimulated renewed interest in the potential for survival and growth of psychrotrophic, nonproteolytic Clostridium botulinum type B spores. As part of a project to better define food-processing requirements, the heat resistance (75 to 90°C) of nonproteolytic C. botulinum type B spores was assessed in turkey containing 1 to 3% (wt/vol) salt (sodium chloride). Heated spores were recovered both on reinforced clostridial medium (RCM) with lysozyme and on RCM having the same salt levels as the heating menstruum. When the recovery medium contained no salt, D-values in turkey slurry containing 1% salt were 42.1, 17.1, 7.8, and 1.1 min at 75, 80, 85, and 90°C, respectively. Increasing levels (2 and 3%, wt/vol) of salt in the turkey slurry reduced the heat resistance as evidenced by reduced spore D-values. Also, apparent or measured heat resistance was decreased with increasing salt concentration in the heating menstruum and the recovery medium. The z-values in turkey slurry for all treatments were similar, ranging from 8.47 10 10.08°C.These data will assist food processors to design thermal processes that ensure safety against nonproteolytic C. botulinum type B spores in cook/chill foods while minimizing quality losses.

Heat Resistance of Clostridium botulinum Type B Spores Grown from Isolates from Commercially Canned Mushrooms1

1978 ◽  
Vol 41 (5) ◽  
pp. 351-353 ◽  
Author(s):  
THERON E. ODLAUG ◽  
IRVING J. PFLUG ◽  
DONALD A. KAUTTER
Keyword(s):  
Heat Resistance ◽  
Phosphate Buffer ◽  
Clostridium Botulinum ◽  
Type B ◽  
Botulinum Type ◽  
C Value ◽  
The Mean ◽  
D Values

The heat resistance of ten Clostridium botulinum type B spore crops was determined in mushroom puree and 0.067M Sorenson phosphate buffer (pH 7). The spore crops were grown from Clostridium botulinum isolates obtained from commercially canned mushrooms. The D-values for all of the C. botulinum spore crops were overall slightly higher in the buffer than in mushroom puree. The mean D(110.0 C)-value for the ten spore crops in buffer was 1.17 min and for the spores in mushroom puree the mean D(110.0 C)-value was 0.78 min. The mean D(115.6 C)-value in buffer for the ten spore crops was 0.24 min compared to a mean D(115.6 C)-value of 0.19 min for spores in mushroom puree. The C. botulinum type B spores tested in this study had a heat resistance that was less than the classical heat resistance for C. botulinum spores.

Cryo-electron microscopy of two-dimensional crystals of reduced type B botulinum neurotoxin

1992 ◽  
Vol 50 (1) ◽  
pp. 530-531
Author(s):  
P. F. Flicker ◽  
V.S. Kulkarni ◽  
J. P. Robinson ◽  
G. Stubbs ◽  
B. R. DasGupta
Keyword(s):  
Disulfide Bonds ◽  
Clostridium Botulinum ◽  
Structural Changes ◽  
Two Dimensional ◽  
Type B ◽  
Single Chain ◽  
Muscle Paralysis ◽  
Cryo Electron Microscopy ◽  
Disulfide Linkages ◽  
Intracellular Action

Botulinum toxin is a potent neurotoxin produced by Clostridium botulinum. The toxin inhibits release of neurotransmitter, causing muscle paralysis. There are several serotypes, A to G, all of molecular weight about 150,000. The protein exists as a single chain or or as two chains, with two disulfide linkages. In a recent investigation on intracellular action of neurotoxins it was reported that type B neurotoxin can inhibit the release of Ca++-activated [3H] norepinephrine only if the disulfide bonds are reduced. In order to investigate possible structural changes in the toxin upon reduction of the disulfide bonds, we have prepared two-dimensional crystals of reduced type B neurotoxin. These two-dimensional crystals will be compared with those of the native (unreduced) type B toxin.

scholarly journals Identification of protein receptor for Clostridium botulinum type B neurotoxin in rat brain synaptosomes.

1994 ◽  
Vol 269 (14) ◽  
pp. 10498-10503 ◽  
Author(s):  
T. Nishiki ◽  
Y. Kamata ◽  
Y. Nemoto ◽  
A. Omori ◽  
T. Ito ◽  
...  
Keyword(s):  
Rat Brain ◽  
Clostridium Botulinum ◽  
Type B ◽  
Rat Brain Synaptosomes ◽  
Protein Receptor ◽  
Botulinum Type ◽  
Brain Synaptosomes

scholarly journals Development of a Combined Selection and Enrichment PCR Procedure for Clostridium botulinum Types B, E, and F and Its Use To Determine Prevalence in Fecal Samples from Slaughtered Pigs

2001 ◽  
Vol 67 (10) ◽  
pp. 4781-4788 ◽  
Author(s):  
Maria Dahlenborg ◽  
Elisabeth Borch ◽  
Peter Rådström
Keyword(s):  
Sample Preparation ◽  
Fecal Sample ◽  
Clostridium Botulinum ◽  
Geographical Location ◽  
Type B ◽  
Fecal Samples ◽  
Pcr Assays ◽  
Combined Selection ◽  
Spore Load ◽  
Slaughtered Pigs

ABSTRACT A specific and sensitive combined selection and enrichment PCR procedure was developed for the detection of Clostridium botulinum types B, E, and F in fecal samples from slaughtered pigs. Two enrichment PCR assays, using the DNA polymeraserTth, were constructed. One assay was specific for the type B neurotoxin gene, and the other assay was specific for the type E and F neurotoxin genes. Based on examination of 29 strains of C. botulinum, 16 strains of other Clostridium spp., and 48 non-Clostridium strains, it was concluded that the two PCR assays detect C. botulinum types B, E, and F specifically. Sample preparation prior to the PCR was based on heat treatment of feces homogenate at 70°C for 10 min, enrichment in tryptone-peptone-glucose-yeast extract broth at 30°C for 18 h, and DNA extraction. The detection limits after sample preparation were established as being 10 spores per g of fecal sample for nonproteolytic type B, and 3.0 × 103 spores per g of fecal sample for type E and nonproteolytic type F with a detection probability of 95%. Seventy-eight pig fecal samples collected from slaughter houses were analyzed according to the combined selection and enrichment PCR procedure, and 62% were found to be PCR positive with respect to the type B neurotoxin gene. No samples were positive regarding the type E and F neurotoxin genes, indicating a prevalence of less than 1.3%. Thirty-four (71%) of the positive fecal samples had a spore load of less than 4 spores per g. Statistical analysis showed that both rearing conditions (outdoors and indoors) and seasonal variation (summer and winter) had significant effects on the prevalence of C. botulinum type B, whereas the effects of geographical location (southern and central Sweden) were less significant.

scholarly journals Study on potential Clostridium botulinum growth and toxin production in Parma ham

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Giuseppe Merialdi ◽  
Mattia Ramini ◽  
Giovanni Parolari ◽  
Silvana Barbuti ◽  
Maria Angela Frustoli ◽  
...  
Keyword(s):  
Clostridium Botulinum ◽  
Toxin Production ◽  
Limiting Factor ◽  
In Vitro Test ◽  
Type B ◽  
Potential Growth ◽  
Parma Ham ◽  
Nacl Concentration ◽  
Vitro Test

The objective of this study was to investigate <em>Clostridium botulinum</em> growth and toxin production in the industrially manufactured Italian Parma ham. The study focuses on the Parma ham production phase identified as maximum risk to <em>C. botulinum</em> proliferation, <em>i.e.</em> the transition from cold phase (salting and resting) to a phase carried out at temperature between 15 and 23°C (drying). A preliminary in vitro test was carried out in order to verify the capability of 6 <em>C. botulinum</em> strains (1 type A, 4 type B, and 1 type E strains) to grow in conditions of temperature, pH and NaCl concentration comparable to those of the beginning stage of ham drying. Five <em>C. botulinum</em> strains grew at 20°C and pH 6, four strains produced toxin when inoculated at a concentration equal to 10<sup>3</sup> cfu/mL at NaCl concentration of 4%, while when the inoculum concentration was 10 cfu/mL, NaCl concentration of 3% resulted the toxin-genesis limiting factor. An experimental contamination with a mixture of the 5 <em>C. botulinum</em> strains selected by the preliminary in vitro test was performed on 9 thighs inoculated at the end of the resting phase. The study was designed to evaluate the potential growth and toxin production in extremely favourable conditions for the bacterium. Type B proteolytic <em>C. botulinum</em> toxin was produced after 14 days of incubation at 20°C in 2 thighs characterised by high weight, low number of days of resting and anomalous physiochemical characteristics [one for very low NaCl concentration (1.59%), the other for elevated pH (6.27) and both for high water activity values (&gt;0.970)]. The results of this research confirm that the cold resting step is a critical phase in the production process of Parma ham for the investigated hazard. Based on the present study, the long resting phase adopted in the manufacturing of Parma ham is proven effective to prevent the growth of <em>C. botulinum</em>, an event which could not otherwise be excluded if the hams were processed under less stringent technological conditions.

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