SOME OBSERVATIONS OF THE EFFECT OF FILTRATES OF SEVERAL REPRESENTATIVE CONCOMITANT BACTERIA ON CLOSTRIDIUM BOTULINUM TYPE A

1961 ◽  
Vol 7 (4) ◽  
pp. 633-639 ◽  
Author(s):  
F. D. Crisley ◽  
G. E. Helz

Filtrates of growing cultures of Bacillus sphacricus, Clostridium sporogenes, Escherichia coli, and Streptococcus faecalis inhibited germination of spores of Clostridium botulinum type A. Of the four filtrates only that of E. coli was inactive at low (1:8) concentrations, and all were inhibitory at high (1:2) levels. Only filtrates of B. sphaericus and C. sporogenes affected lysis (increased) of washed cells of C. botulinum, and only S. faecalis filtrate altered botulinal toxigenicity in a complete medium. S. faecalis filtrate enhanced the final toxicity when present in high concentrations in the presence of phosphate buffer.

2003 ◽  
Vol 66 (8) ◽  
pp. 1402-1407 ◽  
Author(s):  
N. R. REDDY ◽  
H. M. SOLOMON ◽  
R. C. TETZLOFF ◽  
E. J. RHODEHAMEL

The effects of high-pressure treatments at various temperature-time combinations on the inactivation of spores of Clostridium botulinum type A strains 62-A and BS-A in phosphate buffer (0.067 M, pH 7.0) and in a crabmeat blend were investigated. The log unit reduction of strain 62-A spores increased significantly as the processing pressure increased from 417 to 827 MPa (from 60,000 to 120,000 lb/in2) at 75°C. The reduction of BS-A and 62-A spores in either medium increased as processing temperatures increased from 60 to 75°C and processing times increased from 5 to 15 or 20 min at a maximum pressure of 827 MPa. Approximately 2- and 3-log reductions of BS-A and 62-A spores, respectively, in phosphate buffer were obtained at the maximum pressure–maximum temperature combination of 827 MPa and 75°C for a processing time of 20 min. Processing for 15 min at the maximum pressure–maximum temperature combination resulted in maximum reductions of 3.2 and 2.7 log units for BS-A and 62-A spores, respectively, in the crabmeat blend. Results obtained in this study indicate that the crabmeat blend did not protect BS-A and 62-A spores against inactivation by high-pressure processing.


1991 ◽  
Vol 54 (8) ◽  
pp. 648-649 ◽  
Author(s):  
HAIM M. SOLOMON ◽  
DONALD A. KAUTTER ◽  
E. JEFFERY RHODEHAMEL ◽  
TIMOTHY LILLY

A variety of unacidified products bottled in oil or water were investigated for their ability to support growth and toxin production by Clostridium botulinum. The products were inoculated with a mixture of five strains of C. botulinum type A spores (about 50 spores/g or ml) and incubated at room temperature (23°C). At monthly intervals the organoleptic acceptability of the products, as determined by appearance, odor, and texture, was evaluated and a portion of each sample was removed, diluted 1:2 in gel-phosphate buffer, and injected intraperitoneally into mice. At the end of 4 months the drained solids of each sample were macerated with a minimal amount of buffer and centrifuged; the clear extracts were then injected into mice. None of the products tested supported growth and toxin production by C. botulinum.


2008 ◽  
Vol 27 (7-8) ◽  
pp. 420-425 ◽  
Author(s):  
Michael A. Lietzow ◽  
Elizabeth T. Gielow ◽  
Denise Le ◽  
Jifeng Zhang ◽  
Marc F. Verhagen

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.


2013 ◽  
Vol 33 (8) ◽  
pp. 963-969 ◽  
Author(s):  
Eduardo C. Cruz Junior ◽  
Felipe M. Salvarani ◽  
Rodrigo O.S. Silva ◽  
Marcos X. Silva ◽  
Francisco C.F. Lobato ◽  
...  

The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis.


Sign in / Sign up

Export Citation Format

Share Document