Bacterial Spore Injury — An Update1

1981 ◽  
Vol 44 (10) ◽  
pp. 776-786 ◽  
Author(s):  
P. M. FOEGEDING ◽  
F. F. BUSTA
Keyword(s):  
Antimicrobial Agents ◽  
Bacterial Spore ◽  
Bacterial Spores ◽  
Research Activity ◽  
Apparent Survival ◽  
Chemical Treatments ◽  
Spore Resistance ◽  
Fundamental Research ◽  
Increased Sensitivity ◽  
Germination And Growth

Injury has long been recognized in bacterial spores, especially in evaluation of apparent survival after administration of treatments to control these resistant entities. Compared to vegetative cells, the complexity of the germination and outgrowth processes has retarded research activity on injury and resuscitation. Heat-injury has been observed and studied to the greatest extent, but irradiation and chemical treatments also damage spores from anaerobic or aerobic bacteria. Injury has been associated with germination or specific steps in outgrowth or both. Damage of enzymes, DNA, RNA, membranes or other systems may be implied by resuscitation studies. Injury has been manifested by increased sensitivity to selective or antimicrobial agents or by increased requirements for germination and growth. The need for extensive fundamental research on bacterial spore injury continues to exist, especially to aid in explaining unique spore resistance.

Heterogeneity and the modelling of bacterial spore death: the case of continuously decreasing death rate

1977 ◽  
Vol 23 (11) ◽  
pp. 1501-1507 ◽  
Author(s):  
Ken Sharpe ◽  
Roger M. Bektash
Keyword(s):  
Heat Resistance ◽  
Death Rate ◽  
Bacterial Spore ◽  
Bacterial Spores ◽  
Heating Process ◽  
Published Data ◽  
Model Based

Models for the inactivation of bacterial spores for the case of continuously decreasing death rate are reviewed and extended to show that it is not possible to distinguish between one particular model based upon the innate heterogeneity of the population and that based upon the acquisition of heat resistance during the heating process. Two innate heterogeneity models have been fitted to published data.

scholarly journals Evaluation of toxic effect of bamboo preservatives on Lactuca sativa germination and growth

2021 ◽  
Vol 43 ◽  
pp. e34
Author(s):  
Hugo Rocha Scharfenberg ◽  
Marcos Massao Shimano ◽  
Antônio Ludovico Beraldo ◽  
Ana Carolina Borella Marfil Anhê
Keyword(s):  
Electrical Conductivity ◽  
Boric Acid ◽  
Toxic Effect ◽  
Environmental Impacts ◽  
Copper Sulfate ◽  
Root Development ◽  
Lactuca Sativa ◽  
Environmental Risks ◽  
Chemical Treatments ◽  
Germination And Growth

Materials such as wood and bamboo in their various applications are subject to degradation by deteriorating organisms like fungi and insects. Chemical treatments are routinely used by bamboo professionals aiming to control this degradation. However, it is usual the dispose of these used solutions on soil and the environmental risks and effects on vegetation of this improper disposal are still unknown. Thus, this study aims to evaluate the phytotoxicity of CCB solutions (compound based on copper, chromium and boron), tetrahydrate sodium octaborate and CB (copper sulfate with boric acid) under different concentrations in the germination and development of lettuce (Lactuca sativa). The pH and electrical conductivity of the prepared solutions were also measured. The results show that the three preservatives are phytotoxic and inhibit root development, even after dilutions of 50 times that used by professionals. Thus, the disposal of these effluents in the soil or water bodies may have negative environmental impacts on vegetation, requiring treatment after use on preservation of the culms or higher dilutions of the effluents before the disposal.

scholarly journals Bacterial spores and chemical sporicidal agents.

1990 ◽  
Vol 3 (2) ◽  
pp. 99-119 ◽  
Author(s):  
A D Russell
Keyword(s):  
Living Cells ◽  
Bacterial Spores ◽  
Development Of Resistance ◽  
Chemical Agents ◽  
Spore Resistance ◽  
Late Event

Bacterial spores are among the most resistant of all living cells to biocides, although the response depends on the stage of sporulation. The development of resistance to some agents such as chlorhexidine occurs much earlier in sporulation than does resistance to glutaraldehyde, which is a very late event. During germination or outgrowth or both, resistance is lost and the cells become as susceptible to biocides as nonsporulating bacteria. Mechanisms of spore resistance to, and the action of, biocides are discussed, and possible means of enhancing antispore activity are considered. The clinical and other uses of sporicidal and sporostatic chemical agents are described.

scholarly journals Decapsulation of Dextran by Destruction of Polyelectrolyte Microcapsule Nanoscale Shell by Bacillus subtilis Bacteria

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Egor V. Musin ◽  
Aleksandr L. Kim ◽  
Alexey V. Dubrovskii ◽  
Ekaterina B. Kudryashova ◽  
Sergey A. Tikhonenko
Keyword(s):  
Bacillus Subtilis ◽  
Nutrient Medium ◽  
Bacterial Spore ◽  
New Method ◽  
Bacterial Spores ◽  
Polyelectrolyte Microcapsules ◽  
Membrane Shell ◽  
Polyelectrolyte Microcapsule ◽  
Polyallylamine Hydrochloride

One of the prerequisites of successful address delivery is controlling the release of encapsulated drugs. The new method of bacterial spore encapsulation in polyelectrolyte microcapsules allows for degrading the nanoscale membrane shell of microcapsules. The possibility of encapsulating spore forms of Bacillus subtilis in polystyrenesulfonate sodium/ polyallylamine hydrochloride (PSS/PAH) polyelectrolyte microcapsules was demonstrated. The activation and growth on a nutrient medium of encapsulated bacterial spores led to 60% degradation of the microcapsules nanoscale membrane shell. As a result, 18.5% of Fluorescein isothiocyanatedextran was encapsulated into polyelectrolyte microcapsules, and 28.6% of the encapsulated concentration of FITC-dextran was released into the solution.

Use of Antimicrobial Spray Applied with an Inside–Outside Birdwasher To Reduce Bacterial Contamination on Prechilled Chicken Carcasses

1998 ◽  
Vol 61 (7) ◽  
pp. 829-832 ◽  
Author(s):  
ZHONGPING YANG ◽  
YANBIN LI ◽  
MICHAEL SLAVIK
Keyword(s):  
Antimicrobial Agents ◽  
Tap Water ◽  
Cetylpyridinium Chloride ◽  
Setting Time ◽  
Aerobic Bacteria ◽  
Chemical Treatments ◽  
Chicken Carcass ◽  
Sodium Bisulfate ◽  
Chicken Skin ◽  
Poultry Processing

Antimicrobial sprays applied using a modified inside–outside birdwasher to reduce Salmonella typhimurium and total aerobic bacteria on prechilled chicken carcasses were evaluated in a poultry processing pilot plant. Four Chemicals, including trisodium phosphate (TSP, 10%), lactic acid (LAC, 2%), cetylpyridinium chloride (CPC, 0.5%), and sodium bisulfate (SBS, 5%) were selected to be tested as antimicrobial agents. Each chicken carcass was inoculated by spraying the outside and inside of each carcass with S. typhimurium at 105 CFU per carcass. The inoculated carcasses then were passed through the birdwasher and sprayed with selected Chemicals at 35°C at a pressure of 413 kPa for 17 s. After a 60-s setting time on a shackle line, the carcasses were sprayed with tap water to rinse off Chemical residue. All the Chemical treatments reduced Salmonella on the chicken carcasses by approximately 2 log10 CFU per carcass. Total aerobes on the chicken carcasses, however, were reduced by 2.16, 1.66, 1.03, and 0.74 log10 CFU per carcass after spraying with 0.5% CPC, 5% SBS, 2% LAC, or 10% TSP, respectively. Spray treatments of both SBS and LAC caused slight discoloration in part of the chicken skin. The most effective antimicrobial spray treatment for reducing both Salmonella and total aerobes on prechilled chicken carcasses was 0.5% CPC.

scholarly journals Screening of a Leptospira biflexa Mutant Library To Identify Genes Involved in Ethidium Bromide Tolerance

2014 ◽  
Vol 80 (19) ◽  
pp. 6091-6103 ◽  
Author(s):  
Helena Pětrošová ◽  
Mathieu Picardeau
Keyword(s):  
Antibiotic Resistance ◽  
Ethidium Bromide ◽  
Antimicrobial Agents ◽  
Genetic Manipulation ◽  
Content Type ◽  
Transposon Insertion ◽  
Damage Repair ◽  
Transposon Mutants ◽  
Living Species ◽  
Increased Sensitivity

ABSTRACTLeptospiraspp. are spirochete bacteria comprising both pathogenic and free-living species. The saprophyteL. biflexais a model bacterium for studying leptospiral biology due to relative ease of culturing and genetic manipulation. In this study, we constructed a library of 4,996 random transposon mutants inL. biflexa. We screened the library for increased susceptibility to the DNA intercalating agent, ethidium bromide (EtBr), in order to identify genetic determinants that reduceL. biflexasusceptibility to antimicrobial agents. By phenotypic screening, using subinhibitory EtBr concentrations, we identified 29 genes that, when disrupted via transposon insertion, led to increased sensitivity of the bacteria to EtBr. At the functional level, these genes could be categorized by function as follows: regulation and signaling (n= 11), transport (n= 6), membrane structure (n= 5), stress response (n= 2), DNA damage repair (n= 1), and other processes (n= 3), while 1 gene had no predicted function. Genes involved in transport (including efflux pumps) and regulation (two-component systems, anti-sigma factor antagonists, etc.) were overrepresented, demonstrating that these genes are major contributors to EtBr tolerance. This finding suggests that transport genes which would prevent EtBr to enter the cell cytoplasm are critical for EtBr resistance. We identified genes required for the growth ofL. biflexain the presence of sublethal EtBr concentration and characterized their potential as antibiotic resistance determinants. This study will help to delineate mechanisms of adaptation to toxic compounds, as well as potential mechanisms of antibiotic resistance development in pathogenicL. interrogans.

scholarly journals Alteration of menaquinone isoprenoid chain length and antibiotic sensitivity by single amino acid substitution in HepT

2020 ◽  
Author(s):  
Suresh Panthee ◽  
Atmika Paudel ◽  
Hiroshi Hamamoto ◽  
Anne-Catrin Uhlemann ◽  
Kazuhisa Sekimizu
Keyword(s):  
Chain Length ◽  
High Performance ◽  
Antimicrobial Agents ◽  
Antibiotic Sensitivity ◽  
Single Amino Acid ◽  
Chain Elongation ◽  
Spectrometric Analysis ◽  
Classical Pathway ◽  
Increased Sensitivity ◽  
Definition Of

AbstractObjectivesStaphylococcus aureus Smith strain is a historical strain widely used for research purposes in animal infection models for testing the therapeutic activity of antimicrobial agents. We found that it displayed higher sensitivity towards lysocin E, a menaquinone (MK) targeting antibiotic, compared to other S. aureus strains. Therefore, we further explored the mechanism of this hypersensitivity.MethodsMK production was analyzed by high-performance liquid chromatography and mass spectrometric analysis. S. aureus Smith genome sequence was completed using a hybrid assembly approach, and the MK biosynthetic genes were compared with other S. aureus strains. The hepT gene was cloned and introduced into S. aureus RN4220 strain using phage mediated recombination, and lysocin E sensitivity was analyzed by the measurement of minimum inhibitory concentration and colony-forming units.ResultsWe found that Smith strain produced MKs with the length of the side chain ranging between 8 – 10, as opposed to other S. aureus strains that produce MKs 7 – 9. We revealed that Smith strain possessed the classical pathway for MK biosynthesis like the other S. aureus. HepT, a polyprenyl diphosphate synthase involved in chain elongation of isoprenoid, in Smith strain was unique with a Q25P substitution. Introduction of hepT from Smith to RN4220 led to the production of MK-10 and an increased sensitivity towards lysocin E.ConclusionsWe found that HepT was responsible for the definition of isoprenoid chain length of MKs and antibiotic sensitivity.

scholarly journals Characterization of Spontaneously Arising Chlorhexidine-Tolerant Variants inStreptococcus mutans

2019 ◽  
Author(s):  
Justin R. Kaspar ◽  
Matthew J. Godwin ◽  
Irina M. Velsko ◽  
Vincent P. Richards ◽  
Robert A. Burne
Keyword(s):  
Antimicrobial Agents ◽  
Acid Tolerance ◽  
Oral Streptococci ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Single Nucleotide ◽  
Oral Biofilms ◽  
Glycolipid Synthesis ◽  
Increased Sensitivity

ABSTRACTBroad spectrum antimicrobials, both in dental products and within the clinic, have been used in the suppression of cariogenic bacteria such asStreptococcus mutansfor over 40 years. One such antimicrobial is chlorhexidine (CHX), and serves as a standard in dental research against which other antimicrobial therapies are compared against for their efficacy. However, very little is known about the mode of action for CHX against Streptococci and whether tolerance can be developed from repeated exposures. Here, we begin to answer such questions by passagingS. mutanswith increasing concentrations of CHX and isolating spontaneously-arising tolerant variants (CTVs) from separate lineages. We find that these CTVs display a higher minimal inhibitory concentration (MIC) against CHX than the wild-type strain and have altered virulence properties such as acid tolerance and biofilm formation. We record higher MICs for the variants against both daptomycin and bacitracin, but find increased sensitivity to triclosan and sodium fluoride. Measurements of antagonistic capabilities against other health-associated oral streptococci show decreased bacteriocin production compared to wild-type and increased sensitivity to hydrogen peroxide. Finally whole genome sequencing of the CTVs show common single nucleotide polymorphisms (SNPs) within a diacylglycerol kinase homolog and a glycolipid synthesis enzyme, altering LTA accumulation and potentially lipid profile of the cell wall. Together, these findings confirm that streptococci may develop tolerance to antimicrobial agents such as CHX but in the case ofS. mutans,increased tolerance may come at a fitness cost for survival within oral biofilms that keeps variants suppressed within the population.

scholarly journals Mechanism of Sporicidal Activity for the Synergistic Combination of Peracetic Acid and Hydrogen Peroxide

2015 ◽  
Vol 82 (4) ◽  
pp. 1035-1039 ◽  
Author(s):  
Mark J. Leggett ◽  
J. Spencer Schwarz ◽  
Peter A. Burke ◽  
Gerald McDonnell ◽  
Stephen P. Denyer ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Bacterial Spores ◽  
Spore Coat ◽  
Synergistic Activity ◽  
Wild Type ◽  
Spore Resistance ◽  
Bacterial Endospores ◽  
Synergistic Combination ◽  
Reaction Vessels

ABSTRACTThere is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H2O2) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H2O2against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H2O2to PAA formation. This study confirmed the synergistic activity of the combination of H2O2and PAA. However, we observed that the sporicidal activity of the combination is largely due to PAA and not H2O2. Furthermore, we observed that the synergistic combination was based on H2O2compromising the spore coat, which was the main spore resistance factor, likely allowing better penetration of PAA and resulting in the increased sporicidal activity.

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