Application of Nisin and Pediocin against Resistance and Germination of Bacillus Spores in Sous Vide Products

2009 ◽  
Vol 72 (3) ◽  
pp. 515-523 ◽  
Author(s):  
M. L. CABO ◽  
B. TORRES ◽  
J. J. R. HERRERA ◽  
M. BERNÁRDEZ ◽  
L. PASTORIZA
Keyword(s):  
Vegetative State ◽  
Bacillus Species ◽  
Processed Foods ◽  
Positive Interaction ◽  
Minimally Processed ◽  
Vegetative Cells ◽  
Additional Challenge ◽  
Bacillus Spores ◽  
Sous Vide ◽  
High Concentrations

Sous vide and other mild preservation techniques are increasingly demanded by consumers. However, spores often will survive in minimally processed foods, causing both spoilage and safety problems. The main objective of the present work was to solve an industrial spoilage problem associated with two sous vide products: mushrooms and shellfish salad. Bacillus subtilis and Bacillus licheniformis predominated as the most heat-resistant organisms isolated from mushrooms and shellfish salad, respectively. The combined effects of nisin and pediocin against resistance and germination of both Bacillus species were described by empirical equations. Whereas nisin was more effective for decreasing thermal resistance of B. subtilis spores, pediocin was more effective against B. licheniformis. However, a significant positive interaction between both biopeptides for decreasing the proportion of vegetative cells resulting from thermoresistant spores was demonstrated in later experiments, thus indicating the increased efficacy of applying high concentrations of both bacteriocins. This efficacy was further demonstrated in additional challenge studies carried out at 15°C in the two sous vide products: mushrooms and shellfish salad. Whereas no vegetative cells were detected after 90 days in the presence of bacteriocins, almost 100% of the population in nontreated samples of mushrooms and shellfish salad was in the vegetative state after 17 and 43 days of storage at 15°C, respectively.

DETECTION AND DIFFERENTIATION OF SPORE AND VEGETATIVE FORMS OF BACILLUS SPP. USING INFRARED SPECTROSCOPIC METHODS

2008 ◽  
Vol 18 (02) ◽  
pp. 417-427
Author(s):  
DIANE ST. AMANT ◽  
MARK CAMPBELL ◽  
ANDREW BECK ◽  
LESLIE WILLIAMS ◽  
JENNIFER MINTER ◽  
...  
Keyword(s):  
Thin Film ◽  
Infrared Spectroscopy ◽  
Attenuated Total Reflection ◽  
Bacillus Species ◽  
Infrared Spectrometry ◽  
Limited Information ◽  
Transmission Method ◽  
Vegetative Cells ◽  
Bacillus Spp ◽  
Bacillus Spores

Infrared spectroscopy has been demonstrated as a powerful tool for taxonomic classification of bacteria when the microbes are grown and sampled under carefully controlled conditions. Infrared spectroscopy affords limited information about relative proportions of certain chemical functional groups in whole microbial cells. The objective of this work is to elucidate the ability of infrared spectroscopy to identify and speciate Bacillus spp. regardless of sample history. Spectrometers utilize different scanning methods to collect infrared absorption spectra. We employed three; transmission through a thin film, transmission infrared microscopy, and Attenuated Total Reflection (ATR). Target organisms include Bacillus anthracis, and several near neighbors. Each strain was cultured at 24°C and 35°C on three solid media. Microorganisms were incubated for up to ten days to include vegetative cells, spore formation and mature spores. Triplicate microbe samples were prepared and analyzed according to instrument requirements using the three measurement modes. Triplicate samples of BSL-3 organisms were analyzed only by the thin film transmission method. Spectral data was analyzed using the cluster analysis function of OPUS software. We report that infrared spectrometry is capable of discerning Bacillus spores from vegetative cells and the phylogenic clustering of Bacillus species according to pathogenicity levels via infrared spectral analysis.

Biofilm-Spore Response in Bacillus cereus and Bacillus subtilis during Nutrient Limitation

2006 ◽  
Vol 69 (5) ◽  
pp. 1168-1172 ◽  
Author(s):  
D. LINDSAY ◽  
V. S. BRÖZEL ◽  
A. VON HOLY
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Cereus ◽  
Growth Conditions ◽  
Bacillus Species ◽  
Practical Consideration ◽  
Limited Growth ◽  
Vegetative Cells ◽  
Bacillus Subtilis 168 ◽  
Standard Plate ◽  
Bacillus Spores

This study aimed to trace the dynamics of biofilm formation by vegetative cells and endospores of Bacillus cereus DL5 and Bacillus subtilis 168. Counts of B. cereus DL5 and B. subtilis 168 vegetative cells and spores either attached to glass wool or, correspondingly, planktonic cells were determined by standard plate-counting methods. Results from this study highlighted the biofilm-forming potential of both spores and vegetative cells of two different Bacillus species. It was shown that once Bacillus spores had attached to a surface, the spores germinated under favorable (B. cereus DL5) and even unfavorable (B. subtilis 168) nutrient conditions, resulting in biofilms containing both spores and vegetative populations. Furthermore, it was suggested that vegetative B. cereus DL5 cells exhibited a low propensity for spore formation in attached and planktonic growth forms in nutrient-limited growth medium. By contrast, vegetative B. subtilis 168 cells readily formed spores in planktonic and attached microcosms when exposed to nutrient-limited growth conditions. Sporulation in attached Bacillus populations is an important practical consideration for many food industries, such as dairy processing, where bacilli are routinely isolated from populations attached to processing-equipment surfaces.

The Infrared Spectra of Bacillus Bacteria Part I: Vegetative Bacillus versus Sporulated Cells and the Contributions of Phospholipids to Vegetative Infrared Spectra

2009 ◽  
Vol 63 (8) ◽  
pp. 899-907 ◽  
Author(s):  
Timothy J. Johnson ◽  
Yin-Fong Su ◽  
Nancy B. Valentine ◽  
Helen W. Kreuzer-Martin ◽  
Karen L. Wahl ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Vegetative State ◽  
Bacillus Species ◽  
Ir Absorption ◽  
Cell Debris ◽  
Phosphatidyl Glycerol ◽  
Vegetative Cells ◽  
Ir Absorption Spectra ◽  
Soluble Species ◽  
Carbonyl Bond

This paper highlights the distinctions between the infrared (IR) absorption spectra of vegetative versus sporulated Bacillus bacteria. It is observed that there are unique signatures clearly associated with either the sporulated or vegetative state and that vegetative cells (or cell debris) can contribute to the spore spectra. A distinct feature at ∼1739 cm−1 appears to be unique to vegetative cell spectra and can also be used as an indicator of vegetative cells or cell debris in the spore spectra. The data indicate that the band arises from a lipid-soluble species such as an ester or phospholipid carbonyl bond and are consistent with it being either phosphatidyl glycerol (PG) or phosphatidylethanolamine (PE), two major classes of phospholipids found in vegetative cells of Bacillus species. A companion work discusses bands associated with the sporulated state.

Three Clusters of Bacillus Pseudobacteremia Related to a Radiometric Blood Culture Analyzer

1984 ◽  
Vol 5 (2) ◽  
pp. 71-74 ◽  
Author(s):  
Inge Gurevich ◽  
Patricia Tafuro ◽  
Sharon P. Krystofiak ◽  
Robert D. Kalter ◽  
Burke A. Cunha
Keyword(s):  
Blood Culture ◽  
Clinical Signs ◽  
Blood Cultures ◽  
Bacillus Species ◽  
Common Source ◽  
Air Conditioner ◽  
Close Proximity ◽  
Bacillus Spp ◽  
Multiple Blood ◽  
Bacillus Spores

AbstractDuring a ten-month period from September 1981 to July 1982 three episodes of pseudobacteremia due to Bacillus species occurred at this 550-bed institution. The first involved eight isolates, the second 11, and the third seven isolates of the organism, all with the same antibiogram.The patients involved did not exhibit clinical signs of septicemia, and in only one case was more than one specimen per patient positive when multiple blood samples were obtained. Occasional blood cultures of Bacillus species identified in between clusters revealed a different antibiogram.Extensive epidemiologic investigation of patient locations, phlebotomists, and time of cultures yielded no common source. Components involved in the transport and processing of blood cultures, including the radiometric blood culture processor, were also sampled but without recovery of the organism. After the last episode, a layer of dust was noted inside the machine, and culture of this dust grew Bacillus spp. with the same antibiogram as those found in the blood cultures. The filter from an air conditioning unit in close proximity to the machine grew several species of Bacillus.It is presumed that Bacillus spores in the dust were introduced into the blood culture bottles following the heat sterilization of the gas sampling (inoculation/removal) needles.Modification of the cover of the machine was undertaken to prevent access of dust bearing microbes to the inside of the machine. In addition, maintenance now includes regular disinfection/cleaning of the “floor” of the machine, and more frequent changes of the air conditioner filter.

Inability of Pediococcus pentosaceus to Inhibit Clostridium botulinum in sous vide Beef With Gravy at 4 and 10°C

1994 ◽  
Vol 57 (2) ◽  
pp. 104-107 ◽  
Author(s):  
ALLISON D. CRANDALL ◽  
KAREN WINKOWSKI ◽  
THOMAS J. MONTVILLE
Keyword(s):  
Immunosorbent Assay ◽  
Clostridium Botulinum ◽  
Assay Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
Processed Meat ◽  
Minimally Processed ◽  
False Negatives ◽  
Pediococcus Pentosaceus ◽  
Heat Treated ◽  
Sous Vide

The ability of Pediococcus pentosaceus to inhibit Clostridium botulinum toxigenesis in minimally heat-treated, vacuum-packaged sous vide-type beef with gravy was investigated. The bacteriocinogenic strain P. pentosaceus ATCC 43200 and the nonbacteriocinogenic strain P. pentosaceus 43NP1 were coinoculated with proteolytic and nonproteolytic C. botulinum types A and B spores into minimally processed meat with gravy. Toxin was present in samples inoculated with C. botulinum alone by day 31 at 4°C and by day 6 at 10°C. When coinoculated with C. botulinum, neither strain of Pediococcus was capable of significantly delaying the appearance of toxin. Although an enzyme-linked immunosorbent assay method for botulinal toxin was useful for screening toxin-positive samples, a high proportion of false negatives was revealed by confirmatory mouse bioassays. This research confirms that, if botulinal spores are present, sous vide beef does present a botulinal hazard, even when kept under adequate refrigeration.

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