Clostridium botulinum spores in Polish honey samples

Novel induction of broad-spectrum antibiotics by the human pathogen Legionella

The majority of antibiotics are natural products, with microorganism-generated molecules and their derivatives being the most prevalent source of drugs to treat infections. Thus, identifying natural products remains the most valuable resource for novel therapeutics. Here, we report the discovery of a series of dormant bacteria in honey that have bactericidal activity toward Legionella, a bacterial pathogen that causes respiratory disease in humans. We show that, in response to bacterial products secreted by Legionella, the honey bacteria release diffusible antimicrobial molecules. Remarkably, the honey bacteria only produce these molecules in response to Legionella spp., when compared to a panel of 24 bacterial pathogens from different genera. However, the molecules induced by Legionella have broad activity against several clinically important pathogens, including many high-priority pathogens. Thus, Legionella spp. are potent drivers of antimicrobial molecule production by uncharacterized bacteria isolated from honey, providing access to new antimicrobial products and an unprecedented strategy for discovering novel antibiotics.

IMPORTANCE

Natural products generated by microorganisms remain the most viable and abundant source of new antibiotics. However, their discovery depends on the ability to isolate and culture the producing organisms and to identify conditions that promote antibiotic production. Here, we identify a series of previously undescribed bacteria isolated from raw honey and specific culture conditions that induce the production of antimicrobial molecules that are active against a wide variety of pathogenic bacteria.

Real-time PCR assays that detect genes for botulinum neurotoxin A-G subtypes

The role of Real-Time PCR assays for surveillance and rapid screening for pathogens is garnering more and more attention because of its versatility and ease of adoption. The goal of this study was to design, test, and evaluate Real-Time TaqMan PCR assays for the detection of botulinum neurotoxin (bont/A-G) genes from currently recognized BoNT subtypes. Assays were computationally designed and then laboratory tested for sensitivity and specificity using DNA preparations containing bont genes from 82 target toxin subtypes, including nine bivalent toxin types; 31 strains representing other clostridial species; and an extensive panel that consisted of DNA from a diverse set of prokaryotic (bacterial) and eukaryotic (fungal, protozoan, plant, and animal) species. In addition to laboratory testing, the assays were computationally evaluated using in silico analysis for their ability to detect bont gene sequences from recently identified toxin subtypes. Seventeen specific assays (two for each of the bont/C, bont/D, bont/E, and bont/G subtypes and three for each of the bont/A, bont/B, and bont/F subtypes) were designed and evaluated for their ability to detect bont genes encoding multiple subtypes from all seven serotypes. These assays could provide an additional tool for the detection of botulinum neurotoxins in clinical, environmental and food samples that can complement other existing methods used in clinical diagnostics, regulatory, public health, and research laboratories.

Natural agents as wound-healing promoters

The management of acute and chronic wounds resulting from diverse injuries poses a significant challenge to clinical practices and healthcare providers. Wound healing is a complex biological process driven by a natural physiological response. This process involves four distinct phases, namely hemostasis, inflammation, proliferation, and remodeling. Despite numerous investigations on wound healing and wound dressing materials, complications still persist, necessitating more efficacious therapies. Wound-healing materials can be categorized into natural and synthetic groups. The current study aims to provide a comprehensive review of highly active natural animal and herbal agents as wound-healing promoters. To this end, we present an overview of in vitro, in vivo, and clinical studies that led to the discovery of potential therapeutic agents for wound healing. We further elucidated the effects of natural materials on various pharmacological pathways of wound healing. The results of previous investigations suggest that natural agents hold great promise as viable and accessible products for the treatment of diverse wound types.

Microbiological Quality of Polish Artisanal Varietal Honeys

On the basis of routine microbiological tests and selected physicochemical parameters, the quality and food safety of Polish varietal honeys were evaluated. The study included 21 honey samples from 5 varieties (multifloral, honeydew, rapeseed, buckwheat and linden), in which the moisture and extract content, water activity, pH and free acids were determined, and the colony count, the presumptive Bacillus spp., the total fungal count and the presence of anaerobic spore-forming bacilli were examined. More than half (52%, 11/21) of the analyzed honeys contained fewer microorganisms than 10 cfu/g, and in the remaining samples, their numbers ranged from 5 × 101 cfu/g to 4.5 × 102 cfu/g. In all the honeys, the number of presumptive Bacillus spp. in 1 g was less than 10 cfu. In 81% (17/21) of the samples, the total count of fungi in 1 g of honey was less than 10 cfu, and the most contaminated was buckwheat honey (3 samples). The anaerobic spore-forming bacteria was detected in 0.1 g only in one sample of buckwheat honey. The values of the physicochemical parameters did not exceed the accepted limits, which indicated that the honey environment was unfavourable for the development of the tested microbial profile.

Complete Genome Sequence of Bacillus safensis Strain AHB2, Isolated from African Raw Honey from Kajo Keji, South Sudan

We report the complete genome sequence of Bacillus safensis strain AHB2, isolated from African raw honey originating in Kajo Keji, South Sudan, and purchased from a third-party vendor. The genome consists of 3,785,324 bp encompassing 3,774 predicted protein-coding sequences and 183 RNA genes.

Complete Genome Sequence of an African Raw Honey Bacterial Isolate, Bacillus safensis Strain AHB11

We present the complete genome sequence of Bacillus safensis strain AHB11, which was isolated from African raw honey from Kajo Keji, South Sudan, that had been purchased from a third-party vendor. The genome is composed of a 3,697,357-bp chromosome and a 7,105-bp plasmid, collectively encompassing 3,699 predicted protein-coding sequences and 110 RNA genes.

High-Pressure-Based Strategies for the Inactivation of Bacillus subtilis Endospores in Honey

Honey is a value-added product rich in several types of phenolic compounds, enzymes, and sugars recently explored in biomedical and food applications. Nevertheless, even though it has a low water activity (a_W ≈ 0.65) that hinders the development of pathogenic and spoilage microorganisms, it is still prone to contamination by pathogenic microorganisms (vegetative and spores) and may constitute harm to special groups, particularly by immunosuppressed people and pregnant women. Thus, an efficient processing methodology needs to be followed to ensure microbial safety while avoiding 5-hydroxymethylfurfural (HMF) formation and browning reactions, with a consequent loss of biological value. In this paper, both thermal (pressure-assisted thermal processing, PATP) and nonthermal high-pressure processing (HPP), and another pressure-based methodology (hyperbaric storage, HS) were used to ascertain their potential to inactivate Bacillus subtilis endospores in honey and to study the influence of a_W on the inactivation on this endospore. The results showed that PATP at 600 MPa/15 min/75 °C of diluted honey (52.9 °Brix) with increased a_W (0.85 compared to ≈0.55, the usual honey a_W) allowed for inactivating of at least 4.0 log units of B. subtilis spores (to below detection limits), while HS and HPP caused neither the germination nor inactivated spores (i.e., there was neither a loss of endospore resistance after heat shock nor endospore inactivation as a consequence of the storage methodology). PATP of undiluted honey even at harsh processing conditions (600 MPa/15 min/85 °C) did not impact the spore load. The results for diluted honey open the possibility of its decontamination by spores’ inactivation for medical and pharmaceutical applications.

Rapid Detection of Clostridium botulinum in Food Using Loop-Mediated Isothermal Amplification (LAMP)

Botulinum neurotoxins are considered as one of the most potent toxins and are produced by Clostridium botulinum. It is crucial to have a rapid and sensitive method to detect the bacterium Clostridium botulinum in food. In this study, a rapid detection assay of C. botulinum in food using loop-mediated isothermal amplification (LAMP) technology was developed. The optimal primers were identified among three sets of primers designed specifically based on the partial ntnh gene encoding nontoxic-nonhaemagglutinin (NTNH) for rapid detection of the target DNA in plasmids. The optimal temperature and reaction time of the LAMP assay were determined to be 64 °C and 60 min, respectively. The chemical kit could be assembled based on these optimized reaction conditions for quick, initial high-throughput screening of C. botulinum in food samples. The established LAMP assay showed high specificity and sensitivity in detecting the target DNA with a limit of 0.0001 pg/ul (i.e., ten times more sensitive than that of the PCR method) and an accuracy rate of 100%. This study demonstrated a potentially rapid, cost-effective, and easy-operating method to detect C. botulinum in food and clinical samples based on LAMP technology.

Botulinum Toxin as a Biological Warfare Agent: Poisoning, Diagnosis and Countermeasures

Botulinum toxin is a neurotoxin produced by Clostridium botulinum and some other relative species. It causes a lethal disease called botulism. It can enter the body via infections by Clostridium (e.g. wound and children botulism) or by direct contact with the toxin or eating contaminated food (food-borne botulism). Botulinum toxin is also considered as a relevant biological warfare agent with an expected high number of causalities when misused for bioterrorist or military purposes. The current paper surveys the actual knowledge about botulinum toxin pathogenesis, the manifestation of poisoning, and current trends in diagnostics and therapeutics. Relevant and recent literature is summarized in this paper.

Clostridium botulinum and Clostridium perfringens Occurrence in Kazakh Honey Samples

The aim of this study was to assess occurrence of Clostridium botulinum and Clostridium perfringens in honey samples from Kazakhstan. Analyses were carried out using a set of PCR methods for identification of anaerobic bacteria, and detection of toxin genes of C. botulinum and C. perfringens. Among 197 samples, C. botulinum was noticed in only one (0.5%). The isolated strain of this pathogen showed the presence of the bont/A and ntnh genes. C. perfringens strains were isolated from 18 (9%) samples, and mPCR (multiplex PCR) analysis led to them all being classified as toxin type A with the ability to produce α toxin. Sequence analysis of 16S rDNA genes showed occurrence in 4 samples of other anaerobes related to C. botulinum, which were C. sporogenes and C. beijerinckii strains. C. botulinum prevalence in honey samples from Kazakhstan in comparison to the prevalence in samples collected from the other regions seems to be less. The highest prevalence of Clostridium sp. was noticed in the East Kazakhstan province. Our study is the first survey on BoNT-producing clostridia and C. perfringens prevalence in Kazakh honey.