Effect of High Pressures in Combination with Temperature on the Inactivation of Spores of Nonproteolytic Clostridium botulinum Types B and F

2018 ◽  
Vol 81 (2) ◽  
pp. 261-271 ◽  
Author(s):  
GUY E. SKINNER ◽  
TRAVIS R. MORRISSEY ◽  
EDUARDO PATAZCA ◽  
VIVIANA LOEZA ◽  
LINDSAY A. HALIK ◽  
...  
Keyword(s):  
Protective Effect ◽  
Clostridium Botulinum ◽  
High Pressures ◽  
High Pressure Processing ◽  
Process Temperature ◽  
Most Probable Number ◽  
Probable Number ◽  
D Values ◽  
The Impact ◽  
Pressure Combination

ABSTRACT The impact of high pressure processing on the inactivation of spores of nonproteolytic Clostridium botulinum is important in extended shelf life chilled low-acid foods. The three most resistant C. botulinum strains (Ham-B, Kap 9-B, and 610-F) were selected for comparison of their thermal and pressure-assisted thermal resistance after screening 17 nonproteolytic C. botulinum strains (8 type B, 7 type E, and 2 type F). Spores of strains Ham-B, Kap 9-B, and 610-F were prepared using a biphasic media method, diluted in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7.00) to 105 to 106 CFU/mL, placed into a modified sterile transfer pipette, heat sealed, and subjected to a combination of high pressures (600 to 750 MPa) and high temperatures (80 to 91°C) using laboratory and pilot-scale pressure test systems. Diluted spores from the same crops were placed in nuclear magnetic resonance tubes, which were heat sealed, and subjected to 80 to 91°C in a Fluke 7321 high precision bath with Duratheram S oil as the heat transfer fluid. After incubation for 3 months, survivors in both studies were determined by the five-tube most-probable-number method using Trypticase–peptone–glucose–yeast extract broth. The highest (>5.0) log reductions in spore counts for Ham-B, Kap 9-B, and 610-F occurred at the highest temperature and pressure combination tested (91°C and 750 MPa). Thermal D-values of Ham-B, Kap 9-B, and 610-F decreased as the process temperature increased from 80 to 87°C, decreasing to <1.0 min at 87°C for these strains. Pressure-assisted thermal D-values of Ham-B, Kap 9-B, and 610-F decreased as the process temperature increased from 80 to 91°C with any pressure combination and decreased to <1.0 min as the pressure increased from 600 to 750 MPa at 91°C. Based on the pressure-assisted thermal D-values, pressure exerted a more protective effect on spores of Ham-B, Kap 9-B, and 610-F when processed at 83 to 91°C combined with pressures of 600 to 700 MPa when compared with thermal treatment only. No protective effect was observed when the spores of Ham-B, Kap9-B, and 610-F were treated at lower temperatures (80 to 83°C) in combination with 750 MPa. However, at higher temperatures (87 to 91°C) in combination with 750 MPa, a protective effect was seen for Ham-B, Kap9-B, and 610-F spores based on the calculated pressure-assisted thermal D-values.

Combined High Pressure and Thermal Processing on Inactivation of Type E and Nonproteolytic Type B and F Spores of Clostridium botulinum

2014 ◽  
Vol 77 (12) ◽  
pp. 2054-2061 ◽  
Author(s):  
GUY E. SKINNER ◽  
KRISTIN M. MARSHALL ◽  
TRAVIS R. MORRISSEY ◽  
VIVIANA LOEZA ◽  
EDUARDO PATAZCA ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermal Processing ◽  
Clostridium Botulinum ◽  
High Pressures ◽  
Genetic Relatedness ◽  
Test System ◽  
High Pressure Processing ◽  
Type B ◽  
Genetic Fingerprint ◽  
D Values

The aim of this study was to determine the resistance of multiple strains of the three nonproteolytic types of Clostridium botulinum (seven strains of type E, eight of type B, and two of type F) spores exposed to combined high pressure and thermal processing. The resistance of spores suspended in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7) was determined at a process temperature of 80°C with high pressures of 600, 650, and 700 MPa using a laboratory-scale pressure test system. Spores of C. botulinum serotype E strains demonstrated less resistance than nonproteolytic spores of type B or F strains when processed at 80°C and 600 MPa for up to 15 min. All C. botulinum type E strains were reduced by >6.0 log units within 5 min under these conditions. Among the nonproteolytic type B strains, KAP 9-B was the most resistant, resulting in reductions of 2.7, 5.3, and 5.5 log, coinciding with D-values of 7.7, 3.4, and 1.8 min at 80°C and 600, 650, and 700 MPa, respectively. Of the two nonproteolytic type F strains, 610F was the most resistant, showing 2.6-, 4.5-, and 5.3-log reductions with D-values of 8.9, 4.3, and 1.8 min at 80°C and 600, 650, and 700 MPa, respectively. Pulsed-field gel electrophoresis was performed to examine the genetic relatedness of strains tested and to determine if strains with similar banding patterns also exhibited similar D-values. No correlation between the genetic fingerprint of a particular strain and its resistance to high pressure processing was observed.

Combined High Pressure and Thermal Processing on Inactivation of Type A and Proteolytic Type B Spores of Clostridium botulinum

2013 ◽  
Vol 76 (8) ◽  
pp. 1384-1392 ◽  
Author(s):  
N. RUKMA REDDY ◽  
KRISTIN M. MARSHALL ◽  
TRAVIS R. MORRISSEY ◽  
VIVIANA LOEZA ◽  
EDUARDO PATAZCA ◽  
...  
Keyword(s):  
High Pressure ◽  
Thermal Processing ◽  
Clostridium Botulinum ◽  
High Pressures ◽  
Type A ◽  
Test System ◽  
High Pressure Processing ◽  
Type B ◽  
Botulinum Type ◽  
D Values

The aim of this study was to determine the resistance of multiple strains of Clostridium botulinum type A and proteolytic type B spores exposed to combined high pressure and thermal processing and compare their resistance with Clostridium sporogenes PA3679 and Bacillus amyloliquefaciens TMW-2.479-Fad-82 spores. The resistance of spores suspended in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7.0) was determined at a process temperature of 105°C, with high pressures of 600, 700, and 750 MPa by using a laboratory-scale pressure test system. No surviving spores of the proteolytic B strains were detected after processing at 105°C and 700 MPa for 6 min. A >7-log reduction of B. amyloliquefaciens spores was observed when processed for 4 min at 105°C and 700 MPa. D-values at 105°C and 700 MPa for type A strains ranged from 0.57 to 2.28 min. C. sporogenes PA3679 had a D-value of 1.48 min at 105°C and 700 MPa. Spores of the six type A strains with high D-values along with C. sporogenes PA3679 and B. amyloliquefaciens were further evaluated for their pressure resistance at pressures 600 and 750 MPa at 105°C. As the process pressure increased from 600 to 750 MPa at 105°C, D-values of some C. botulinum strains and C. sporogenes PA3679 spores decreased (i.e., 69-A, 1.91 to 1.33 min and PA3679, 2.35 to 1.29 min). Some C. botulinum type A strains were more resistant than C. sporogenes PA3679 and B. amyloliquefaciens to combined high pressure and heat, based on D-values determined at 105°C. Pulsed-field gel electrophoresis (PFGE) was also performed to establish whether strains with a similar restriction banding pattern also exhibited similar D-values. However, no correlation between the genomic background of a strain and its resistance to high pressure processing was observed, based on PFGE analysis. Spores of proteolytic type B strains of C. botulinum were less resistant to combined high pressure and heat (700 MPa and 105°C) treatment when compared with spores of type A strains.

Prevalence of Clostridium botulinum in Commercial Liver Sausage

1983 ◽  
Vol 46 (3) ◽  
pp. 242-244 ◽  
Author(s):  
A. H. W. HAUSCHILD ◽  
R. HILSHEIMER
Keyword(s):  
Clostridium Botulinum ◽  
Type A ◽  
Most Probable Number ◽  
Confidence Limits ◽  
Probable Number ◽  
Toxic Cultures

Samples of 75 g of commercial liver sausage were cultured, with and without prior heating, for the presence of viable Clostridium botulinum. Three of 276 heated cultures and 2 of 276 unheated cultures produced botulinal toxin, all of type A. The most probable number of botulinal spores was estimated at 0.15/kg. The estimate for “total” C. botulinum, based on 5 toxic cultures in 276 heated and unheated pairs, was 0.24/kg. The 99% confidence limits were 0.02 to 0.53 per kg and 0.05 to 0.69 per kg, respectively .

Thermal Inactivation of Borrelia burgdorferi, the Cause of Lyme Disease

1990 ◽  
Vol 53 (4) ◽  
pp. 296-299 ◽  
Author(s):  
SI K. LEE ◽  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Borrelia Burgdorferi ◽  
Thermal Inactivation ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Most Probable Number ◽  
Lag Phase ◽  
Probable Number ◽  
Heat Treated ◽  
Thermal Death ◽  
D Values

Borrelia burgdorferi strain EBNI was cultivated in BSK-II medium at 34°C, then cultures at different physiological states were heat-treated at temperatures in the range of 50 to 70°C. Numbers of survivors were estimated by the Most Probable Number technique. Log MPN was plotted against treatment time, and resulting survivor curves were linear. Estimated D-values for cultures incubated at 34°C for 7 d before heat-treatment were 5.5, 4.3, 2.7, .47, and .14 min at 50, 55, 60, 65, and 70°C, respectively. Spirochetes in the lag phase had greater resistance to heat than those in the stationary phase, with the latter being more resistant to heat than spirochetes in the same phase of growth but refrigerated at 4°C for 3 d. D-values for B. burgdorferi are generally less at 50°C, and greater at 70°C than those reported for other nonsporeforming pathogens. When log10 MPN was plotted against treatment temperature, two linear segments for each thermal death curve were obtained. Our data show the spirochete had higher z-values than most nonsporeforming pathogens. The pH of the medium, in the range of 5.0 to 7.6, did not affect resistance of B. burgdorferi to heat.

Survival of Borrelia burgdorferi in Whole Milk, Low Fat Milk, and Skim Milk at 34°C and in Skim Milk at 5°C

1991 ◽  
Vol 54 (7) ◽  
pp. 532-536 ◽  
Author(s):  
GERALDINE M. FARRELL ◽  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Borrelia Burgdorferi ◽  
Milk Protein ◽  
Skim Milk ◽  
Storage Period ◽  
Most Probable Number ◽  
Low Fat ◽  
Probable Number ◽  
Whole Milk ◽  
The Mean ◽  
D Values

Autoclaved whole milk, low-fat milk, protein-fortified skim milk and regular skim milk were inoculated to contain ca. 105 to 106 Borrelia burgdorferi strains 35210, 35211, or EBNI/ml and stored at 34°C for 16 d. Similarly inoculated skim milk also was held at 5°C for 46 d. Numbers of survivors were estimated by the Most Probable Number (MPN) technique. In all instances, numbers of B. burgdorferi decreased over the storage period. At 34°C, no strain of B. burgdorferi was detected after day 12. The mean D-values, at 34°C, for strains 35210, 35211, and EBNI were 2.2, 2.4, and 2.2 d, respectively. The mean D-values, at 34°C, for all strains in whole milk, low-fat milk, protein-fortified skim milk, and regular skim milk were 2.4, 2.3, 1.9, and 2.4 d, respectively. At 5°C, spirochete numbers in regular skim milk decreased, but all three strains remained at a detectable level for 46 d. The mean D-values, at 5°C, for strains 35210, 35211, and EBNI were 12, 15, and 12 d, respectively.

Incidence of Clostridium botulinum in Commercial Bacon

1980 ◽  
Vol 43 (7) ◽  
pp. 564-565 ◽  
Author(s):  
A. H. W. HAUSCHILD ◽  
R. HILSHEIMER
Keyword(s):  
Confidence Limit ◽  
Clostridium Botulinum ◽  
Most Probable Number ◽  
Probable Number

Of 416 75-g samples of commercial bacon cultured with or without prior heating. only one gave rise to formation of botulinal toxin. The most probable number of Clostridium botulinum was estimated at 0.064 per kg, with a 99% confidence limit of 0.0004 to 0.478 per kg.

scholarly journals The Impact of Water Intrusion on Pathogenic Vibrio Species to Inland Brackish Waters of China

2020 ◽  
Vol 17 (18) ◽  
pp. 6781
Author(s):  
Qingyao Wang ◽  
Songzhe Fu ◽  
Qian Yang ◽  
Jingwei Hao ◽  
Can Zhou ◽  
...  
Keyword(s):  
Seawater Intrusion ◽  
Water Area ◽  
Vibrio Species ◽  
Most Probable Number ◽  
Potential Health ◽  
Probable Number ◽  
Inland River ◽  
Pathogenic Vibrio ◽  
The Impact ◽  
Vibrio Spp

The estuary is the ecological niche of pathogenic Vibrio spp. as it provides abundant organic and inorganic nutrients from seawater and rivers. However, little is known about the ecology of these Vibrio species in the inland brackish water area. In this study, their co-occurrence and relationships to key environmental constraints (salinity and temperature) in the Hun-Tai River of China were examined using the most probable number polymerase chain reaction (MPN-PCR) approach. We hereby report 2-year continuous surveillance based on six water indices of the Hun-Tai River. The results showed that seawater intrusion maximally reached inland as far as 26.5 km for the Hun-Tai River. Pathogenic Vibrio spp. were detected in 21.9% of the water samples. In particular, V. cholerae, V. parahaemolyticus, and V. vulnificus were isolated in 10 (10.4%), 20 (20.8.5%), and 2 (2.08%) samples, respectively. All V. parahaemolyticus strains were tdh gene negative, 10% were positive for the trh gene. Multi-locus sequence typing (MLST) divided V. parahaemolyticus strains into 12 sequence types (STs) for the Hun-Tai River. Five STs were respectively present in various locations along the Hun-Tai River. The PCR assay for detecting six virulence genes and Vibrio seventh pandemic island I and II revealed three genotypes in 12 V. cholerae isolates. The results of our study showed that seawater intrusion and salinity have profound effects on the distribution of pathogenic Vibrio spp. in the inland river, suggesting a potential health risk associated with the waters of the Hun-Tai River used for irrigation and drinking.

High Salinity Relay as a Postharvest Processing Strategy To Reduce Vibrio vulnificus Levels in Chesapeake Bay Oysters (Crassostrea virginica)†

2011 ◽  
Vol 74 (11) ◽  
pp. 1902-1907 ◽  
Author(s):  
CORINNE AUDEMARD ◽  
HOWARD I. KATOR ◽  
MARTHA W. RHODES ◽  
THOMAS GALLIVAN ◽  
A. J. ERSKINE ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
High Salinity ◽  
Vibrio Vulnificus ◽  
Most Probable Number ◽  
Probable Number ◽  
Low Salinity ◽  
Moderate Salinity ◽  
Salinity Increase ◽  
The Impact ◽  
Postharvest Processing

In 2009 the U.S. Food and Drug Administration (FDA) announced its intention to implement postharvest processing (PHP) methods to eliminate Vibrio vulnificus from oysters intended for the raw, half-shell market that are harvested from the Gulf of Mexico during warmer months. FDA-approved PHP methods can be expensive and may be associated with unfavorable responses from some consumers. A relatively unexplored PHP method that uses relaying to high salinity waters could be an alternative strategy, considering that high salinities appear to negatively affect the survival of V. vulnificus. During relay, however, oysters may be exposed to rapid and large salinity increases that could cause increased mortality. In this study, the effectiveness of high salinity relay to reduce V. vulnificus to <30 most probable number (MPN) per g and the impact on oyster mortality were assessed in the lower Chesapeake Bay. Two relay experiments were performed during the summer and fall of 2010. Oysters collected from three grow-out sites, a low salinity site (14 to 15 practical salinity units [psu]) and two moderate salinity sites (22 to 25 psu), were relayed directly to a high salinity site (≥30 psu) on Virginia's Eastern Shore. Oysters were assayed for V. vulnificus and Vibrio parahaemolyticus (another Vibrio species of concern) densities at time 0 prior to relay and after 7 and 14 days of relay, using the FDA MPN enrichment method combined with detection by real-time PCR. After 14 days, both V. vulnificus and V. parahaemolyticus densities were ≤0.8 MPN/g, and decreases of 2 to 3 log in V. vulnificus densities were observed. Oyster mortalities were low (≤<4%) even for oysters from the low salinity harvest site, which experienced a salinity increase of approximately 15 psu. Results, although preliminary and requiring formal validation and economic analysis, suggest that high salinity relay could be an effective PHP method.

scholarly journals Prevalence of Clostridium botulinum in Finnish Trout Farms: Pulsed-Field Gel Electrophoresis Typing Reveals Extensive Genetic Diversity among Type E Isolates

1998 ◽  
Vol 64 (11) ◽  
pp. 4161-4167 ◽  
Author(s):  
Sebastian Hielm ◽  
Johanna Björkroth ◽  
Eija Hyytiä ◽  
Hannu Korkeala
Keyword(s):  
Genetic Diversity ◽  
Gel Electrophoresis ◽  
Clostridium Botulinum ◽  
Pulsed Field Gel Electrophoresis ◽  
Most Probable Number ◽  
Probable Number ◽  
Pulsed Field ◽  
Pfge Typing ◽  
Specific Pcr ◽  
Trout Farms

ABSTRACT The distribution of Clostridium botulinum serotypes A, B, E, and F in Finnish trout farms was examined. A total of 333 samples were tested with a neurotoxin-specific PCR assay. C. botulinum type E was found in 68% of the farm sediment samples, in 15% of the fish intestinal samples, and in 5% of the fish skin samples. No other serotypes were found. The spore counts determined by the most-probable-number method were considerably higher for the sediments than for the fish intestines and skin; the average values were 2,020, 166, and 310 C. botulinum type E spores kg−1, respectively. The contamination rates in traditional freshwater ponds and marine net cages were high, but in concrete ponds equipped with sediment suction devices the contamination rates were significantly lower. Pulsed-field gel electrophoresis (PFGE) typing of 42 isolates obtained in this survey and 12 North American reference strains generated 28 pulsotypes upon visual inspection, suggesting that there was extensive genetic diversity and that the discriminatory power of PFGE typing in C. botulinum type E was high. A numerical analysis of SmaI-XmaI macrorestriction profiles confirmed these findings, as it divided the 54 isolates into 15 clusters at a similarity level of 76%. For this material, this level of similarity corresponded to a three-band difference in the macrorestriction profiles, which indicated that there is no genotypic proof of a close epidemiological relationship among the clusters.

scholarly journals Antibiotic Susceptibility of Bacteria Isolated from Abattoir Effluent-Impacted Tagangu River, Aliero, Kebbi State, North-Western Nigeria

2019 ◽  
pp. 1-8 ◽  
Author(s):  
B. G. Jega ◽  
O. O. Adebisi ◽  
S. S. Manga
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Microbiological Quality ◽  
Most Probable Number ◽  
Resistant Bacteria ◽  
Proteus Vulgaris ◽  
Probable Number ◽  
Antibiotic Susceptibility Test ◽  
The Impact

This study aimed to evaluate the impact of abattoir effluent on microbiological quality of the receiving Tagangu River and the susceptibility of the isolates to commonly-used antibiotics. The most probable number (MPN) as well as the Kirby-Bauer method of antibiotic susceptibility test were used and demonstrated the total heterotrophic bacteria as well as Escherichia coli O157:H7 numbers in a total of 30 water samples collected over a period of three months at three strategic points of the river. In accordance with CLSI guidelines, four out of eight bacteria (Enterobacter sp., Pseudomonas aeruginosa, Proteus vulgaris and Citrobacter sp.) isolated, demonstrated multiple antibiotic resistance (MAR) against at least three out of septrin, chloramphenicol, amoxicillin, augmentin, gentamicin, tarivid and streptomycin. All the isolates (Escherichia coli, Klebsiella pneumoniae, Enterobacter sp., Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter sp., Serratia marcescens and Aerobacter aerogenes) showed either high or intermediate susceptibility to sparfloxacin, ciprofloxacin and pefloxacin. The findings indicated that the river has been heavily polluted with the effluent discharges and did not meet any of the WHO guidelines for natural water sources fit for irrigation or other domestic purposes. As such, indiscriminate discharge of abattoir effluent could impact on the microbiological quality and promote increased incidence of multiple antibiotic resistant bacteria in a receiving river.

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