Coxiella burnetii
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward in Case Studies in Infectious Disease, 2010
The patient is infected with Coxiella burnetii and is suffering from chronic Q fever. C. burnetii is an obligate intracellular bacterium with a complex life cycle and related morphological heterogeneity. It is a pleomorphic coccobacillus 0.3–1.0 μm in size (Figure 2). C. burnetii has a cell wall built of approximately 6.5 nm thick outer and inner membranes, which are separated by a peptidoglycan layer (Figure 3). A spore-like stage does not have dipicolinic acid or a spore coat with cysteine characteristic for other gram-positive bacterial spores. Due to these features C. burnetii is considered to be a gram-negative bacterium, although it is almost impossible to stain C. burnetii by the Gram technique. The Gimenez staining method is usually used instead.
Food Irradiation: Microbiological, Nutritional, and Functional Assessment
Michael Pöschl, Leo M. L. Nollet in Radionuclide Concentrations in Food and the Environment, 2006
Fortunately the most common and most troublesome bacteria are sensitive to radiation and can be reliably eliminated by doses less than 10 kGy. For example, it has been shown that a relatively low irradiation dose of 1.5 kGy is sufficient to give a 10,000-fold reduction in the number of E. coli O157:H7 at 5ºC [34]. This irradiation dose is also sufficient to eliminate Salmonella and Campylobacter from whole-shell eggs without significant adverse effects on the egg quality [35]. Yersinia and Vibrio spp. also have low resistance to ionizing radiation [36,37]. A dose of 2.5 kGy reduced the number of survivors of four Shigella serotypes by more than 6 log-cycles in frozen precooked shrimp in inoculated pack studies [38]. The D10 values of Aeromonas hydrophila were found to be less than 0.5 kGy in ground fish [39]. Bacterial spores belonging to the genera Clostridium and Bacillus are of major concern in the microbiology of high-dose irradiated, high-moisture, low-acid foods because several spore-forming species pose serious health hazards, while many others are associated with food spoilage. In general, spores are highly resistant to radiation, heat, and chemicals. Early studies suggest that certain combination treatments have advantages for inactivation of bacterial spores, the most promising being the combination of radiation with heat and food additives [40].
Bacteria and Bioactive Peptides
Prakash Srinivasan Timiri Shanmugam in Understanding Cancer Therapies, 2018
Spores of genetically modified strain, C. novyi-NT, devoid of the lethal toxin have shown targeted anticancer action without any systemic side effects. An intratumoral and intravenous injection of C. histolyticum and C. sporogenes spores, respectively, caused marked lysis of cancer cells. Additionally, Clostridium was detected only in cancer cells and not in normal tissues of mice after intravenous injection (Thiele et al. 1963). Further, the study demonstrated that C. novyi-NT spores were rapidly cleared from the circulation by the reticuloendothelial system without showing any clinical toxicity. Bacterial spores have also been used as delivery agents for anticancer agents, cytotoxic peptides, and therapeutic proteins, and as vectors for gene therapy.
Fatty acids, esters, and biogenic oil disinfectants: novel agents against bacteria
Published in Baylor University Medical Center Proceedings, 2023
Aruna Lamba, Jonathan Kopel, David Westenberg, Shubhender Kapila
Different microorganisms vary in their response to antiseptics and disinfectants. This is hardly surprising in view of their different cellular structure, composition, and physiology. Traditionally, microbial susceptibility to disinfectants has been classified based on these differences. In recent years, considerable progress has been made in understanding more fully the responses of different types of bacteria (Mycobacterium, nonsporulating bacteria, and bacterial spores) to antibacterial agents. As a result, resistance can either be a natural property of an organism (intrinsic) or acquired through mutation or through acquisition of plasmids (self-replicating, extrachromosomal DNA) or transposons (chromosomal or plasmid integrating, transmissible DNA cassettes).12–15 Intrinsic resistance is demonstrated by many gram-negative bacteria, bacterial spores, Mycobacterium, and Staphylococci. Resistance acquired through plasmid mediation is most widely associated with resistance to mercury compounds and other metallic salts. In recent years, acquired resistance to certain other types of biocides has been observed, notably in Staphylococci. As such, there is growing interest in investigating new disinfectants, such as fatty acid esters and biogenic oil vapors, to address this limitation.
Effect of bacterial toxin identified from the Bacillus subtilis against the Cnaphalocrocis medinalis Guenée (Lepidoptera: Crambidae)
Published in Toxin Reviews, 2023
Ramakrishnan Ramasubramanian, Sengodan Karthi, Sengottayan Senthil-Nathan, Haridoss Sivanesh, Narayanan Shyam Sundar, Vethamonickam Stanley-Raja, Govindaraju Ramkumar, Kanagaraj Muthu-Pandian Chanthini, Prabhakaran Vasantha-Srinivasan, Khaloud Mohammed Alarjani, Mohamed S Elshikh, Ahmed Abdel-Megeed, Patcharin Krutmuang
Entomopathogenic bacterial spores can be effective against insect pests and act as bacterial pesticides. Research continues to demonstrate the application of bacterial-based insecticides against a wide range of insect pests across many cropping systems (Usta 2013, Ruiu 2015). Almost all groups of microbes which include fungi, bacteria, yeast and viruses have members with the potential to produce toxins that can significantly suppress insect survival (Kumari et al. 2014, Chalivendra 2021). The genome B. subtilis encrypts ten chemoreceptors recognized as ligands, which are composed of carbon, amino acids, and oxygen (Hashem et al. 2019). Species of Bacillus generally make endospores to endure under environmental conditions. Spores permit long-term storage of biological control agents and can be delivered using a variety of formulations (Hashem et al. 2019). In general, strains of Bacillus have been shown to produce a natural blend of bio-active metabolites that are effective in controlling insect pests of plants and diseases caused by plant pathogens (Asaka and Shoda 1996, Ghribi et al. 2012). The present study reported on the detrimental effects of B. subtilis on larval stages of C. medinalis when ingested with treated rice leaves.
Faecal banking at –20 °C facilitates faecal microbiota transplantation for recurrent Clostridioides difficile infection in clinical practice
Published in Infectious Diseases, 2020
Reetta Satokari, Lotta Pietilä, Eero Mattila, Perttu Lahtinen, Perttu E. T. Arkkila
The suppression of CDI by FMT coincides with the restoration of microbial diversity and composition, including bile salt hydrolase producing bacteria, in recurrent CDI patients [7–9]. Furthermore, the engraftment of donor-like microbiota and specific bacterial taxa therein in recurrent CDI patients has been associated with successful clinical outcomes of FMT [7–9]. While this study didn´t assess microbiota, we presume that our protocol and faecal banking at –20 °C kept an adequate number of microbes viable and able to exert the therapeutic effect. In this regard, coarse material present in the faeces (faecal matrix) may have protected anaerobic microbes from oxygen during the fast and minimal processing of donated samples as well as acted as a cryoprotectant together with the added glycerol to protect microbes during freezing. Also, it has been shown that a significant proportion of bacteria residing in the human gut are spore-forming organisms [10], and undoubtedly bacterial spores would remain intact during freeze-storage at –20 °C. While microbiology underlying the efficacy of FMT in treating CDI has not been conclusively clarified, we conclude that sufficient activity of mediators is preserved during freezing and storage at –20 °C and the presented protocol is feasible for short-term faecal banking.
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