Gram-positive Spore-forming Bacterium Research Articles

Mapping high probability area for the Bacillus anthracis occurrence in wildlife protected area, South Omo, Ethiopia

Anthrax is a zoonotic disease caused by a spore-forming gram-positive bacterium, Bacillus anthracis. Increased anthropogenic factors inside wildlife-protected areas may worsen the spillover of the disease at the interface. Consequently, environmental suitability prediction for B. anthracis spore survival to locate a high-risk area is urgent. Here, we identified a potentially suitable habitat and a high-risk area for appropriate control measures. Our result revealed that a relatively largest segment of Omo National Park, about 23.7% (1,218 square kilometers) of the total area; 36.6% (711 square kilometers) of Mago National Park, and 29.4% (489 square kilometers) of Tama wildlife Reserve predicted as a high-risk area for the anthrax occurrence in the current situation. Therefore, the findings of this study provide the priority area to focus on and allocate resources for effective surveillance, prevention, and control of anthrax before it causes devastating effects on wildlife.

Complete genome sequence of Thermaerobacter composti strain Ins1, a spore-forming filamentous bacterium isolated from a deep geothermal reservoir.

We report the complete genome sequence of Thermaerobacter composti strain Ins1, a gram-positive filamentous spore-forming bacterium, isolated from deep geothermal fluids used for electricity production. This is the first complete (circular) genome assigned to the species Thermaerobacter composti.

Anti-S-layer monoclonal antibodies impact Clostridioides difficile physiology

ABSTRACT Clostridioides difficile (C. difficile), a gram-positive anaerobic and spore-forming bacterium, is the leading cause of nosocomial antibiotic-associated diarrhea in adults which is characterized by high levels of recurrence and mortality. Surface (S)-layer Protein A (SlpA), the most abundantly expressed protein on the bacterial surface, plays a crucial role in the early stages of infection although the nature of its involvement in C. difficile physiology is yet to be fully understood. Anti-S-layer antibodies have been identified in the sera of convalescent patients and have been correlated with improved outcomes of C. difficile infection (CDI). However, the precise mechanisms by which anti-S-layer antibodies confer protection to the host remain unknown. In this study, we report the first monoclonal antibodies (mAbs) targeting the S-layer of reference strain 630. Characterization of these mAbs unraveled important roles for the S-layer protein in growth, toxin secretion, and biofilm formation by C. difficile, with differential and even opposite effects of various anti-SlpA mAbs on these functions. Moreover, one anti-SlpA mAb impaired C. difficile growth and conferred sensitivity to lysozyme-induced lysis. The results of this study show that anti-S-layer antibody responses can be beneficial or harmful for the course of CDI and provide important insights for the development of adequate S-layer-targeting therapeutics.

Comparative Genomics of Clostridioides difficile.

Clostridioides difficile, a Gram-positive spore-forming anaerobic bacterium, has rapidly emerged as the leading cause of nosocomial diarrhoea in hospitals. The availability of large numbers of genome sequences, mainly due to the use of next-generation sequencing methods, has undoubtedly shown their immense advantages in the determination of C. difficile population structure. The implementation of fine-scale comparative genomic approaches has paved the way for global transmission and recurrence studies, as well as more targeted studies, such as the PaLoc or CRISPR/Cas systems. In this chapter, we provide an overview of recent and significant findings on C. difficile using comparative genomic studies with implications for epidemiology, infection control and understanding of the evolution of C. difficile.

Epidemiologia molecular do Clostridioides difficile obtido de amostras de fezes de animais selvagens no Brasil

ABSTRACT: Clostridioides difficile is a strictly anaerobic, spore-forming Gram-positive bacterium associated with diarrhea, known as C. difficile infection (CDI). In domestic animals, C. difficile is considered an important pathogen mostly in pigs and horses, but there are also reports in other domestic species. In wild animals, the epidemiology of C. difficile is largely unknown, and the role of the bacterium as a cause of diarrhea is unclear. The aim of this study was to determine the prevalence of C. difficile in the feces of wild animals referred to the Center of Medicine and Research in Wild Animals (CEMPAS). Fecal samples obtained from 100 animals of 34 different species were subjected to qPCR for the detection of the C. difficile 16S rRNA gene and two major toxin genes (tcdA and tcdB) and to anaerobic bacterial isolation. A total of 63 animals (63%) were positive for C. difficile by qPCR, and 16 isolates were recovered. The opossum (Didelphis spp.) had the highest number of positive animals in both tests (from 21 samples, 19 were qPCR positive, and four isolates were recovered). Three toxigenic strains (RT 002, 004, and 014), all previously described as infecting humans and animals, were isolated in the following species: bearded dragon (Pogona vitticeps), pampas fox (Lycalopex vetulus), and marmoset (Callithrix sp.). The presence of C. difficile in the feces of wild animals highlights the importance of wildlife as potential carriers of infection for production animals or humans.

Structure and function of the EA1 surface layer of Bacillus anthracis

The Gram-positive spore-forming bacterium Bacillus anthracis is the causative agent of anthrax, a deadly disease mostly affecting wildlife and livestock, as well as representing a bioterrorism threat. Its cell surface is covered by the mutually exclusive S-layers Sap and EA1, found in early and late growth phases, respectively. Here we report the nanobody-based structural characterization of EA1 and its native lattice contacts. The EA1 assembly domain consists of 6 immunoglobulin-like domains, where three calcium-binding sites structure interdomain contacts that allow monomers to adopt their assembly-competent conformation. Nanobody-induced depolymerization of EA1 S-layers results in surface defects, membrane blebbing and cell lysis under hypotonic conditions, indicating that S-layers provide additional mechanical stability to the cell wall. Taken together, we report a complete model of the EA1 S-layer and present a set of nanobodies that may have therapeutic potential against Bacillus anthracis.

New Research on the Bacillus anthracis Genetic Diversity in Siberia.

Anthrax is a particularly dangerous infection of humans and ungulates caused by the Gram-positive spore-forming bacterium Bacillus anthracis. The highly monomorphic and clonal species B. anthracis is commonly divided into three main lineages, A, B, and C, which in turn are divided into several canSNP groups. We report here a phylogenetic analysis based on the whole-genome sequence (WGS) data of fifteen strains isolated predominantly in Siberia or Central and Southern Russia. We confirm the wide distribution of the cluster of strains of the B.Br.001/002 group, endemic to the Russian Arctic, which is also present in the steppe zone of Southern Siberia. We characterize additional branches within the major A.Br.001/002 polytomy comprising the A.Br.Ames and A.Br.Sterne lineages, one of which is identified in the Arctic.

Gut Microbiota Associated with Clostridioides difficile Carriage in Three Clinical Groups (Inflammatory Bowel Disease, C. difficile Infection and Healthcare Workers) in Hospital Field.

Clostridioides difficile is an anaerobic spore-forming Gram-positive bacterium. C. difficile carriage and 16S rDNA profiling were studied in three clinical groups at three different sampling times: inflammatory bowel disease (IBD) patients, C. difficile infection (CDI) patients and healthcare workers (HCWs). Diversity analysis was realized in the three clinical groups, the positive and negative C. difficile carriage groups and the three analysis periods. Concerning the three clinical groups, β-diversity tests showed significant differences between them, especially between the HCW group and IBD group and between IBD patients and CDI patients. The Simpson index (evenness) showed a significant difference between two clinical groups (HCWs and IBD). Several genera were significantly different in the IBD patient group (Sutterella, Agathobacter) and in the CDI patient group (Enterococcus, Clostridioides). Concerning the positive and negative C. difficile carriage groups, β-diversity tests showed significant differences. Shannon, Simpson and InvSimpson indexes showed significant differences between the two groups. Several genera had significantly different relative prevalences in the negative group (Agathobacter, Sutterella, Anaerostipes, Oscillospira) and the positive group (Enterococcus, Enterobacteriaceae_ge and Enterobacterales_ge). A microbiota footprint was detected in C. difficile-positive carriers. More experiments are needed to test this microbiota footprint to see its impact on C. difficile infection.

The potential of the antiplatelet agent ticagrelor as a new antibacterial agent

The number of deaths caused by drug-resistant bacteria is expected to increase in the future, and there is a need to develop new antimicrobial agents. Recently, the antiplatelet drug ticagrelor has been reported to have promising antibacterial properties. The purpose of this review is to analyze articles and case reports that describe the antimicrobial action of ticagrelor. Ticagrelor was found to have antibacterial reactions against Gram-positive bacteria, including drug-resistant and spore-forming bacteria, while no effect was observed against Gram-negative bacteria. In this paper we discuss a new potential antimicrobial agent, ticagrelor.

LysGR1, a novel thermostable endolysin from Geobacillus stearothermophilus bacteriophage GR1.

Geobacillus stearothermophilus is a highly thermophilic, spore-forming Gram-positive bacterium that causes flat sour spoilage in low-acid canned foods. To address this problem, we isolated G. stearothermophilus-infecting phage GR1 from the soil and characterized its endolysin LysGR1. Phage GR1 belongs to the Siphoviridae family and possesses a genome of 79,387 DNA bps with 108 putative open reading frames. GR1 demonstrated a very low degree of homology to previously reported phages, indicating that it is novel. The endolysin of GR1 (LysGR1) contains an N-terminal amidase domain as an enzymatically active domain (EAD) and two C-terminal LysM domains as a cell wall binding domain (CBD). Although GR1 is specific to certain strains of G. stearothermophilus, LysGR1 showed a much broader lytic range, killing all the tested strains of G. stearothermophilus and several foodborne pathogens, such as Clostridium perfringens, Listeria monocytogenes, and Escherichia coli O157:H7. LysGR1_EAD, alone, also exhibits lytic activity against a wide range of bacteria, including Bacillus cereus, which is not terminated by a full-length endolysin. Both LysGR1 and its EAD effectively remove the G. stearothermophilus biofilms and are highly thermostable, retaining about 70% of their lytic activity after a 15-min incubation at 70°C. Considering the high thermal stability, broad lytic activity, and biofilm reduction efficacy of LysGR1 and its EAD, we hypothesize that these enzymes could act as promising biocontrol agents against G. stearothermophilus and as foodborne pathogens.

Plasmid – Chromosome interplay in natural and non-natural hosts: global transcription study of three Bacillus cereus group strains carrying pCER270 plasmid

The Bacillus cereus group comprises genetically related Gram-positive spore-forming bacteria that colonize a wide range of ecological niches and hosts. Despite their high degree of genome conservation, extrachromosomal genetic material diverges between these species. The discriminating properties of the B. cereus group strains are mainly due to plasmid-borne toxins, reflecting the importance of horizontal gene transfers in bacterial evolution and species definition. To investigate how a newly acquired megaplasmid can impact the transcriptome of its host, we transferred the pCER270 from the emetic B. cereus strains to phylogenetically distant B. cereus group strains. RNA-sequencing experiments allowed us to determine the transcriptional influence of the plasmid on host gene expression and the impact of the host genomic background on the pCER270 gene expression. Our results show a transcriptional cross-regulation between the megaplasmid and the host genome. pCER270 impacted carbohydrate metabolism and sporulation genes expression, with a higher effect in the natural host of the plasmid, suggesting a role of the plasmid in the adaptation of the carrying strain to its environment. In addition, the host genomes also modulated the expression of pCER270 genes. Altogether, these results provide an example of the involvement of megaplasmids in the emergence of new pathogenic strains.

Effect of Nanopriming with Selenium Nanocomposites on Potato Productivity in a Field Experiment, Soybean Germination and Viability of Pectobacterium carotovorum

In recent decades, the use of nanocomposites (NCs) in crop production has been actively studied. We have previously shown that chemically synthesized selenium nanocomposites (Se NCs) based on natural polymeric matrices of arabinogalactan (Se/AG NCs), carrageenan (Se/CAR NCs), and starch (Se/ST NCs) stimulated the growth and development of potatoes in vitro and had an antibacterial effect against the phytopathogen Clavibacter sepedonicus. It is important to confirm that the results obtained in the laboratory are also reproducible in the field conditions of crop cultivation. In addition, the applications of NCs can be expanded if a wider range of their biological activity is revealed, and the effect on other types of cultivated plants and phytopathogens is shown. In this regard, the purpose of this research was to study the effect of nanopriming with Se NCs on the productivity of potatoes in a field experiment, the germination of soybeans, and the viability of the phytopathogen Pectobacterium carotovorum under in vitro conditions. The study included the use of traditional methods of conducting a field experiment in natural growing conditions, also using microbiological cultures and studying the bacterial profile from the endosphere of potato tubers by the imprint method, germinating Glycine max L. soybean seeds after nanopriming in Petri dishes, followed by the measurement of morphometric and biochemical parameters such as the activity of antioxidant enzymes and content of diene conjugates. Based on the results of field experiments, it was found that the preplant treatment of tubers with Se/AG and Se/CAR NCs stimulated a significant increase in the number of stems in potato plants and tubers per plant, but for Se/AG NC, the increase was observed only in 2020 and 2022, and the stimulating effect of Se/AG and Se/CAR NCs on the weight of tubers was observed only in 2020. In the yield structure, the proportion of marketable seed tubers was increased under the influence of all Se NCs. Endosphere cultures from tubers showed that bacteria were present in only 56% of the tubers in the control, while 78% of the tubers obtained from plants grown from seed tubers treated with Se/AG NC and 100% of the tubers from plants grown from seed tubers treated with Se/ST and Se/CAR NCs contained bacteria. The bacteria were represented by both spore-forming Gram-positive and Gram-negative bacteria of various sizes. The results presented in this article and previously published data showed that the maximum diversity of bacteria was observed after treatment with Se/ST NC. Experiments on potatoes showed that Se/AG NC had the greatest biological effect. In addition, the growth-stimulating effect of these NCs on the biomass of the roots of soybean seedlings was shown. It activated the antioxidant enzymes and reduced the level of diene conjugates (DCs), the amount of which increased significantly after seed biopriming with the phytopathogen Pectobacterium carotovorum. The antibacterial effect of Se/AG NC in relation to the P. carotovorum was observed as a reduction in the growth of the bacterial culture, biofilm formation, and dehydrogenase activity of cells. Thus, it has been shown that Se/AG NC has a stimulating effect on such agriculturally important crops as potatoes and soybeans, as well as an antibacterial effect against Gram-negative and Gram-positive phytopathogenic bacteria.

Antibiofilm activities of crude extract and supernatant of Actinobacteria against biofilm formed by foodborne pathogens and food spoilage bacteria

Bacteria form a biofilm that attaches the microbial population to a solid surface, thus acting as a barrier to protect external stresses from the bacterial community. In the food industry, biofilms are believed to be responsible for food-borne diseases and food spoilages. This research was conducted to characterize anti-quorum sensing (QS), anti-biofilm activity of crude extract, and supernatant from Actinobacteria isolates against biofilm of foodborne, and food spoilage bacteria. Actinobacteria is the group of filamentous spore-forming Gram-positive bacteria, which is well recognized as a source for novel secondary metabolites, such as anti-biofilm and anti-quorum sensing. Two isolates of Actinobacteria utilized in this study were recovered from the Indonesian marine environment in the previous study. Both isolates demonstrated anti-QS activity on early detection assay using the agar overlay method. The Actinobacteria isolates were fermented, and the crude extracts were obtained through extraction using 100 % ethyl acetate and further evaporation, while the supernatant was collected directly following fermentation. The entire Actinobacteria isolates displayed capability as an anti-biofilm agent in crude extracts form at a concentration of 20 mg.mL-1, alongside when in its supernatant form. The Actinobacteria isolates in both extracts and supernatants form demonstrated anti-QS activity based on the N-Hexanoyl-L- homoserine lactone (HHL) validation assay and were also categorized as non-toxic based on Brine Shrimp Lethality Assay (BSLA).

Antibacterial Activity of Culinary-Medicinal Polypore Mushroom Lentinus tigrinus (Agaricomycetes).

Medicinal mushrooms belonging to Lentinus spp. exhibit significant antibacterial activities, but little attention has been paid to their efficacy against the food-borne pathogen, Bacillus cereus. The present study for the first time quantitatively evaluated the antibacterial activity of different extracts from fruiting bodies of a well-authenticated Iranian native strain of medicinal mushroom, Lentinus tigrinus, against Gram-positive spore-forming bacterium B. cereus. The findings revealed that the acetone extract inhibited the growth of B. cereus at concentrations as low as 31.25 μg/ML, while it had no effect against Escherichia coli and Staphylococcus aureus even at 10,000 μg/ML. The rest of the bacteria were also susceptible to the acetone extract at concentrations greater than 5 mg/ML. Antibacterial activities of the methanol-ethyl acetate extract and the hot water extract were significantly weaker than that of the acetone extract, which contained high amounts of total phenols (5.83 ± 0.08 mg GAE/g, dw), while Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of functional groups, such as hydroxyl, carbonyl, amide, and amine. Further studies by scanning electron microscopy (SEM) confirmed obvious changes in the morphology of B. cereus in response to the acetone extract of L. tigrinus. This study may suggest that L. tigrinus could be a good natural source for isolating and purifying antibacterial compounds against B. cereus.

Determination of Taxonomic Affiliation and Assessment of Biotechnological Potential of an Indigenous Strain of Gram-Positive Spore-Forming Bacteria

The search for new effective strains-producers of enzymes and biologically active substances for the development of new environmentally friendly plant protection products against phytopathogens is a very urgent task for the greening of agriculture. In our work, we used active strains of gram-positive spore-forming bacteria isolated from soil near the roadside zone of the Belgorod region to assess their antagonistic activity to phytopathogens and biotechnological potential. In the course of molecular genetic studies of the 16S rRNA gene of the isolated native strain, a complete similarity of the target with Bacillus subtilis was revealed. When studying morphological and cultural characteristics, it was determined that the cells of the target strain are rod-shaped, arranged singly or in pairs.The conditions of cultivation of the bacterium were revealed, which shows high growth in the composition of the medium containing 3% peptone for 20 hours, the specific increase in biomass exceeded 96%. When evaluating the antagonistic activity, it was revealed that the isolated strain suppresses the growth of cultures of Escherichia coli O157:H7, Aspergillus unguis VKM F-1754 and bacteria of the genus Ralstonia.

Review of the epidemiological situation on Anthrax around the world and the Forecast for Kyrgyzstan

This review, prepared on the basis of WHO materials and from medical websites, and monographs by domestic and foreign researchers, provides information on cases of infection of humans and animals with anthrax in the world. The epidemiological situation for this especially dangerous infection remains quite complicated and is assessed as tense and does not tend to stabilize due to the existence of soil foci, which manifest themselves for many years as periodic outbreaks among farm animals and people. Cutaneous anthrax is an extremely preventable disease, yet still accounts for 95% of all anthrax cases, and has left many regions endemic. The objectives of this study was to review published outbreak investigations for cutaneous anthrax, while examining the current and new risk factors, as well as the present control measures and their effectiveness at preventing future outbreaks. A literature search of articles was performed using PubMed, Google Scholar, and New England Journal of Medicine, website of WHO, (HAW HamburgLibrary). Articles in English and pertaining to human subjects only, were retrieved. Seven articles included in this study examined sources of outbreak for cutaneous anthrax, investigated suspected cases using clinical diagnosis and surveys, and evaluated current control measures. Three studies reported relative risk, suggesting there is a likely association between butchering sick animals and infection. Further findings suggested a correlation between an individual's socioeconomic status and the likelihood of contracting anthrax. Additionally, the quality of livestock in the area can have a cyclical nature on cutaneous anthrax infections among humans. The cumulative evidence concludes that an improvement of surveillance and control measures is needed in endemic regions, and future investigation of new risk factors is required. Anthrax is a highly dangerous zoonotic infectious disease, the causative agent of which is the Gram-positive spore-forming bacterium Bacillus anthracis, which belongs to the pathogenicity group II. Almost all types of warm-blooded animals, including humans, are susceptible to anthrax. For herbivores, the source of infection is soil containing B. anthracis spores. The high resistance of anthrax spores to environmental factors, the ability to persist in the soil for a long time, and under certain conditions to pass into a vegetative form, makes the fight against this infection an extremely difficult task for medicine and veterinary medicine. A person becomes infected by household contact from contaminated objects of animal origin, and from 2,000 to 20,000 people fall ill every year in the world. Although anthrax is well controlled in the developed countries, anthrax remains of a global concern because B. anthracis spores can potentially be used as a biological weapon. On the other hand, some local anthrax outbreak has been recorded in western countries. For example, a case of naturallyacquired inhalation anthrax was reported in London, 2008 and another case was recorded in Scotland in 2006. Both cases were bongo drummers/drum makers who used imported animal hides. As of 14 January 2010, a total of 14 con- firmed cases of anthrax infection in Scotland were reported and 7 of these died. All cases were heroin user. Possible source of infection is said that heroin is transported in animal skin. In developed countries, there is also an infection risk after contact with a commercial product prepared from inadequately treated wool or leather. Products made from contaminated hair (e.g. shaving brush, wool coat), skins (e.g. drums, drumheads made from animal skin), and bone meal (e.g. fertilizer) may continue to be sources of infection for many years. A review of the epidemiological situation on anthrax in the world for 2021 was carried out. In Kyrgyzstan, eight cases of human infection with the cutaneous form of anthrax were registered in the Suzak district of the Jalal-Abad region and 7 cases in the Aksy district. Epizootics of anthrax among farm and wild animals have been identified mainly in the countries of Central Asia, with the largest number of confirmed human cases detected in Kyrgyzstan. Infection of people with the causative agent of anthrax is associated primarily with the ingestion of the meat of sick and dead anthrax animals, contact with animals during forced slaughter, skinning, and processing of contaminated meat. The level of incidence of anthrax in the territory of Kyrgyzstan in 2021 will be determined by a set of planned volumes of preventive measures and, subject to their proper implementation, will be limited to the detection of sporadic cases of infection that are potentially possible within certain regions of Kyrgyzstan.

A study on toxin genes and cytotoxicity levels of Bacillus cereus in various ready-to-eat foods and pastry products in Turkey

Bacillus cereus is a spore-forming and toxin-producing gram-positive bacteria widely isolated from soils, meat, milk, and vegetables. It is recognized as one of the pathogenic bacteria that can lead to food poisoning and food spoilage in food service systems due to its ease of contamination of foods and lack of guarantee of elimination by pasteurization and sanitation practices. B. cereus causes two types of diseases mainly characterized by diarrhea and vomiting type syndrome with the toxins it produces. Toxins produced by B. cereus are mainly heat-stable emetic toxin and three different heat-labile enterotoxins. Foodborne illnesses of the diarrheal type are caused by the single protein toxin; cytotoxin K (CytK), and both tripartite toxins; hemolysin BL (Hbl), and the non-hemolytic enterotoxin (Nhe), whereas the emetic type, is caused by an emetic toxin cereulide. In this study, 225 ready-to-eat foods and pastry products were analyzed for B. cereus, its toxin profiles, and cytotoxicity effects. Multiplex PCR is used to identify the presence of the Hbl, CytK, and emetic toxin encoding genes. Component-specific antibody-based ELISA tests were utilized to determine the Hbl-L2 and NheB components. Cytotoxic activity of the B. cereus isolates on Vero cells was also identified. In total, B. cereus was detected in 37 out of 225 (16.4%) food samples. From the positive 37 B. cereus isolates, the ces gene was not identified, whereas 91.9% (34) Nhe, 56.8% (21) Hbl, and 8.1% (3) CytK encoding genes revealed positive results on PCR analysis. PCR results were also compatible with ELISA and Cytotoxicity tests. In a nutshell, 16.4% prevalence of B. cereus in foods is insufficient, and the presence or absence of toxin genes may not yield reliable results. It is critical to detect pathogenic B. cereus toxin gene profiles as well as toxin production ability at the same time. This study presents for the first time, data from a cell culture cytotoxicity test using specific monoclonal antibody-based sandwich ELISA and multiplex PCR for ready-to-eat foods and pastry products in Turkey

Antibiofilm activities of crude extract and supernatant of Actinobacteria against biofilm formed by foodborne pathogens and food spoilage bacteria

Bacteria form a biofilm that attaches the microbial population to a solid surface, thus acting as a barrier to protect external stresses from the bacterial community. In the food industry, biofilms are believed to be responsible for food-borne diseases and food spoilages. This research was conducted to characterize anti-quorum sensing (QS), anti-biofilm activity of crude extract, and supernatant from Actinobacteria isolates against biofilm of foodborne, and food spoilage bacteria. Actinobacteria is the group of filamentous spore-forming Gram-positive bacteria, which is well recognized as a source for novel secondary metabolites, such as anti-biofilm and anti-quorum sensing. Two isolates of Actinobacteria utilized in this study were recovered from the Indonesian marine environment in the previous study. Both isolates demonstrated anti-QS activity on early detection assay using the agar overlay method. The Actinobacteria isolates were fermented, and the crude extracts were obtained through extraction using 100 % ethyl acetate and further evaporation, while the supernatant was collected directly following fermentation. The entire Actinobacteria isolates displayed capability as an anti-biofilm agent in crude extracts form at a concentration of 20 mg.mL-1, alongside when in its supernatant form. The Actinobacteria isolates in both extracts and supernatants form demonstrated anti-QS activity based on the N-Hexanoyl-L- homoserine lactone (HHL) validation assay and were also categorized as non-toxic based on Brine Shrimp Lethality Assay (BSLA).

Botulism in the Brazilian Amazon: a life-threatening disease in a neglected population.

Botulism is a rare and potentially fatal neuroparalytic syndrome caused by the gram-positive anaerobe spore-forming bacterium Clostridium botulinum. The microorganism produces a neurotoxin that inhibits the presynaptic release of acetylcholine at the neuromuscular junction, clinically leading to a myasthenic syndrome. To describe the recent outbreak of botulism cases and its demographic, clinical, and laboratory characteristics. We report 4 patients with botulism in the recent outbreak occurred between 2017 and 2019 in the state of Amazon. Out of four patients with botulism, three contracted it from eating contaminated food and one had wound botulism. We emphasize the excellent clinical outcome of the different disease presentations in our case series. The temporal proximity of these reports may suggest a new rise in the number of cases in the upcoming years. A possible hypothesis is that the rarity of the disease decreased the awareness regarding the primary prevention or even a diagnosis by an untrained physician.

Optimising Antimicrobial Stewardship to Tackle Clostridioides difficile Infection and Improve Patient Outcomes

Clostridioides difficile, formerly known as Clostridium difficile, is a Gram-positive spore-forming and toxin-producing bacterium that causes diarrhoea in vulnerable patient groups. It is a common hospital-acquired infection but also occurs in the community. Typically, C. difficile colonises the gut in patients experiencing gut dysbiosis, for example, following antimicrobial treatment or chemotherapy. Cases of C. difficile are increasing worldwide, both in healthcare settings and in the community, and are an indicator of widespread antibiotic use. Antimicrobial stewardship (AMS) combines local, national, and international guidelines for good antimicrobial practice, effective monitoring of antimicrobial resistance, and control of antibiotic use. Such strategies are vital in the international drive to stem the rise in antimicrobial resistance and control hospital-acquired infections such as C. difficile. However, implementation of such strategies is often lacking. Resourcing issues and a lack of awareness of current best practices among physicians, prescribers, and the general public are significant barriers to implementation. EMJ spoke with two infectious disease experts: Benoît Guery, University Hospital of Lausanne, Switzerland, and Javier Cobo Reinoso, Hospital Universitario Ramón y Cajal, Madrid, Spain. They highlighted the challenges that face medical practitioners, infectious disease experts, hospital managers, and healthcare providers in developing and implementing effective antimicrobial strategies that support better patient outcomes. The two experts also discussed the changes required to ensure that good AMS can be implemented at local, national, and international levels.