Bacteria

Fungal infections significantly threaten public health, and many strains are resistant to antifungal drugs. Marine Actinobacteria have been identified as the generators of powerful bioactive compounds with antifungal activity and can be used to address this issue. In this context, strains of Actinomycetes were isolated from the marine area of Rachgoun Island, located in western Algeria. The isolates were phenotypically and genetically characterized. The most potent antifungal isolate was selected, and its crude extract was purified and characterized by the GC/MS method. The results revealed that the STR2 strain showed the strongest activity against at least one target fungal species tested on a panel of fungal pathogens, including Candida albicans, Aspergillus fumigatus, Aspergillus niger, and Fusarium oxysporum. The molecular assignment of the STR2 strain based on the 16S rRNA gene positioned this isolate as a Streptomyces bacillaris species. The presence of safranal (2,3-dihydro-2,2,6-trimethylbenzaldehyde) in the crude chloroform extract of Streptomyces bacillaris STR2 strain was discovered for the first time in bacteria using chromatographic analysis of its TLC fractions. Moreover, certain molecules of biotechnological interest, such as phenols, 1,3-dioxolane, and phthalate derivatives, were also identified. This study highlights the potential of marine actinomycetes to produce structurally unique natural compounds with antifungal activity. Full article

Plant pathogenic Pseudomonas species cause a variety of diseases in plants. Each Pseudomonas species employs different virulence factors and strategies for successful infection. Moreover, even the same bacterial pathogens can differentially utilize virulence factors against various host plants. However, there has been relatively less emphasis on comparing the infection strategies of a single bacterial pathogen on different hosts and different bacterial pathogens on a single host. Here, we investigated plant–pathogen interactions using two Pseudomonas species, Pseudomonas cannabina pv. alisalensis (Pcal) KB211 and Pseudomonas syringae pv. tomato (Pst) DC3000, and their host plants, cabbage and tomato. Our findings reveal distinct behaviors and virulence patterns across different host plants. Pcal multiplies to greater levels in cabbage compared to tomato, suggesting that Pcal is more adaptive in cabbage than tomato. Conversely, Pst showed robust multiplication in tomato even at lesser inoculum levels, indicating its aggressiveness in the apoplastic space. Gene expression analyses indicate that these pathogens utilize distinct virulence-related gene expression profiles depending on the host plant. These insights highlight the importance of revealing the spatiotemporal regulation mechanisms of virulence factors. Full article

Streptococcus mutans is primarily found in biofilms on tooth surfaces and is associated with the development of dental caries. S. mutans synthesizes water-insoluble glucan (WIG) using sucrose as a substrate, inducing the formation of three-dimensional biofilms. WIG is produced by glucosyltransferases (GTFs) encoded by the tandem and highly homologous gtfB and gtfC genes. Conversely, the homologous recombination of gtfB and gtfC readily happens, producing natural variants without WIG. These WIG⁻ variants are thought to have ecologically pleiotropic functions; however, the molecular basis for their appearance is unclear. This study aimed to determine the sequence of the gtfB–gtfC regions of WIG⁻ variants. We sequenced the gtfB–gtfC regions of 23 WIG⁻ variants derived from S. mutans UA159 and revealed the presence of five alleles and four types of single homologous recombination patterns. Regardless of the allele type, the WIG⁻ variants showed low biofilm formation and GTF activity. To the best of our knowledge, this is the first study to report the presence of alleles in WIG⁻ variants. These findings provide important information for explaining the appearance of mechanisms in WIG⁻ variants. Full article

Platelets are well known for their role in hemostasis. Additionally, platelets play a crucial role in immune and inflammatory responses. Toll-like receptors (TLRs) can mediate bacterial interactions during infection, triggering platelets to initiate an inflammatory response. TLR-4 receptors enable direct interactions between platelets and the bacterial lipopolysaccharide (LPS) endotoxin. The aim of this study was to assess platelet plug formation in response to LPS from Proteus mirabilis. Human whole blood was treated with varying concentrations of LPS over a range of incubation times. Then, platelet plug formation time was measured, under high shear conditions using the platelet function analyzer PFA-100, as aperture closure time (CT). The addition of either 2 or 10 µg/mL of LPS to 80% whole blood significantly prolonged the CTs even in the absence of preincubation (p = 0.028 or p = 0.049, respectively). With added preincubation of LPS with whole blood, the measured CTs were further prolonged. If the preincubation time was set to 35 min, then even the addition of 0.2 µg/mL of LPS resulted in significant CT prolongation (p < 0.001). Taken together, the platelet plug formation in the presence of collagen/ADP is significantly prolonged by the presence of LPS in a concentration and preincubation time-dependent manner. Exposure to P. mirabilis LPS reduces the platelet aggregation response in human whole blood. Full article

Ceramic and vitreous materials can be functionalized to exhibit biocidal activity. This research evaluates the biocidal properties of silver-modified vitreous microspheres designed to be included in water endpoints and siphons to prevent nosocomial diseases produced in hospital environments. The microspheres obtained from a coating and heat treatment process at 650 °C have been chemically and microstructurally characterized using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Wavelength Dispersive X-ray Fluorescence (WD-XRF), Scanning Electron Microscopy (FEG-SEM) and Energy-dispersive X-ray Microanalysis (EDS) to determine how silver particles are distributed in the glassy matrix and to relate their bactericidal capacity by means of leaching tests. Microbiological tests have been performed against microorganisms such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida auris. The results revealed that these silver-coated microspheres had significant bactericidal activity, with a significant reduction in the population of E. coli, C. auris, and P. aeruginosa, with no cytotoxic effect of these microspheres. Full article

Antiphospholipid syndrome (APS), also known as Hughes syndrome, is a systemic autoimmune disorder characterized by recurrent thrombosis and pregnancy complications, accompanied by the presence of antiphospholipid antibodies (aPLs). These antibodies target anionic phospholipids or protein–phospholipid complexes within cell membranes, contributing to the underlying mechanisms of the disease. Although anticoagulation therapy remains the cornerstone of APS management, it often fails to prevent complications, particularly in obstetric and thrombotic cases. As autoimmune diseases become increasingly linked to alterations in the gut microbiome, this study investigates the complex interaction between gut bacteria and immune modulation in APS. We explore how disruptions in the gut microbiome may influence the development of autoimmune conditions, with a specific focus on APS. By identifying key microorganisms potentially involved in this gut–immune axis, we aim to provide insights into novel preventive and control approaches. Future research should focus on harnessing the gut microbiome to develop more effective treatments that target both the immune system and microbial populations in APS patients. Full article

Bioremediation, the degradation of environmental pollutants by living organisms, has immense potential to lead to a greener planet. Bioinformatics analysis can contribute to the identification of novel microorganisms, which biodegrade contaminants, or of participating proteins and enzymes, and the elucidation of the complex metabolic pathways involved. In this study, we focus on C-P lyase and glyphosate oxidoreductase (Gox), two enzymes which degrade glyphosate, a widely used pesticide. Amino acid sequences of the two enzymes were collected from a broad range of microorganisms using the KEGG database and BLAST. Based on this, we identified additional lineages, with putative glyphosate-degrading activity, for which no glyphosate-degrading species have been reported yet. The conserved residues in each enzyme were identified via multiple alignments and mapped onto the 3D structures of the enzymes, using PyMOL, leading to novel insights into their function. As the experimental structure of Gox is still unknown, we created structural models based on three different programs and compared the results. This approach can be used to yield insights into the characteristics of potential glyphosate-degrading enzymes. Given the limited information available, such a step is important to gain further knowledge about them, which can contribute to their application in bioremediation in the future. Full article

In recent years, the study of antimicrobial peptides (AMPs) has garnered considerable attention due to their potential in combating antibiotic-resistant pathogens. Mass spectrometry-based proteomics provides valuable information on microbial stress responses induced by AMPs. This work aims to unravel the proteomic alterations induced by the amyloidogenic antimicrobial peptide R23I, encompassing both inhibitory and non-inhibitory concentrations. This study investigates the effects of the R23I peptide on the protein abundance of Thermus thermophilus (T. thermophilus) at different concentrations (20, 50, and 100 μg/mL). We found 82 differentially expressed proteins, including 15 upregulated and 67 downregulated proteins. We also compared the protein identification results between the PEAKS and IdentiPy programs. Our proteomic analysis revealed distinct patterns of protein expression, suggesting compensatory mechanisms in response to the R23I peptide. Notably, the alterations predominantly affected membrane and cytoplasmic proteins that play a central role in critical cellular processes such as transcription, translation, and energy conversion. This study sheds light on the complex interactions between antimicrobial peptides and bacterial responses, offering insights into microbial adaptability and potential implications for antimicrobial strategies and the understanding of microbial physiology. Full article

Maize silks (style) receive wind-transmitted pollen. Thereafter, male gametes travel through the silks to reach ovules. Pollinated silks contain a microbiome, members of which are predicted to promote host reproduction and abiotic/biotic stress tolerance during fertilization. It is unknown whether pollinated silk bacteria originate environmentally (air/pollen) or from maternal tissue. Methods are lacking to test microbial colonization of silks in their native habitat [on intact maize inflorescences (cobs) encased by husk leaves]. Current methods focus on naked silks attached to dehusked cob pieces. Here, two novel methods are presented to enable research on silk microbes in their native habitat. Method 1 tests whether silk-associated bacteria with potential environmental origins are attracted toward ovules. Method 2 distinguishes whether a microbe colonizes silks from the environment or maternal parent. Biosafety containment was enabled by housing microbe-treated cobs in large jars. Using these methods, a model bacterial isolate from fertilization-stage silks (DsRed-tagged Pantoea-E04) was shown to colonize husk-covered silks after inoculating exposed silk tips; E04 could not colonize from the cob base, suggesting an environmental origin. In support, E04 colonized silks more frequently when cobs were uncut and oriented vertically. These protocols will enable more biologically relevant investigation of silk microbiomes and pathogens. Full article

The need for sustainable farming practices has brought attention to biofertilizers to improve soil quality and boost crop yield while minimizing environmental impacts. This study explores the potential integration of biofertilizers within push–pull cropping systems, an agroecological approach that utilizes companion cropping to repel and attract pests. This review focuses on how biofertilizers could optimize plant–microbe interactions, promoting nutrient uptake, pest control, and soil health. Key biofertilizers, including nitrogen-fixing, phosphate-solubilizing, and potassium-solubilizing bacteria, improve nutrient availability, which leads to higher crop yields and resilience. They also enhance soil water retention and drought tolerance, which are crucial under changing climate conditions. Biofertilizers support beneficial microbial communities, reducing reliance on synthetic fertilizers and pesticides while fostering disease suppression and stress tolerance in crops. Their effectiveness can be significantly increased when biofertilizers are integrated with push–pull technology (PPT). However, challenges remain, such as inconsistent biofertilizer performance and the complexity of microbial interactions. Overcoming these challenges necessitates a multidisciplinary approach to refining production and application techniques. This study emphasizes the need to investigate biofertilizer-mediated plant–microbiome dynamics further to unlock their full potential. It concludes that future research should focus on the synergies between biofertilizers and agroecological systems to enhance food security and environmental sustainability. This work advances our understanding of optimizing biofertilizers in sustainable farming practices, particularly within the PPT framework. Full article

For years, the Bacillus genus has encompassed a heterogeneous group of individuals whose main common trait was their ability to sporulate in the presence of oxygen. This criterion has been revised, resulting in the reclassification of several species into new genera and to a redefinition of the characteristics of the members of this taxon. Currently, the species of the genus are grouped into the Subtilis clade and the Cereus clade. The former, called Bacillus sensu stricto, initially composed of B. subtilis, B. licheniformis, B. pumilus, and B. amyloliquefaciens, has subsequently incorporated new species related to these. The Cereus clade, Bacillus cereus sensu lato, consists of pathogenic species (B. anthracis, B. cereus, and B. thuringiensis) as well as others of significance in agriculture and industry. Furthermore, identifying these individuals remains complex, requiring alternatives to 16S rRNA sequencing. The ability to form spores resistant to stressful conditions provides a significant advantage over other genera, with observable differences in sporulation rates and spore structure among different species. Additionally, Bacillus spp. are known for their capacity to produce antimicrobial substances, lytic enzymes, and volatile organic compounds, each with diverse applications. Some species are even used as probiotics. This review delves into aspects related to the taxonomy and identification of microorganisms belonging to the genus Bacillus, which often present challenges. The aim is to provide a comprehensive overview of the topic. In addition, it highlights the characteristics and applications of the genus, emphasizing its importance in biotechnology and microbiology. Full article

The Lactobacillales (LB) stand apart among bacterial orders, using manganese (Mn) instead of iron to support their growth and swiftly ferment complex foods while acidifying their environment. The present work investigates whether a shift in the use of Mn could mark the origin of LB. Transmembrane carriers of the ubiquitous Slc11 family play key roles in LB physiology by catalyzing proton-dependent Mn import. In prior studies, the Slc11 clade found in LB (MntH Cb, MCb) showed both remarkable structural plasticity and highly efficient Mn uptake, and another Slc11 clade, MCg1, demonstrated divergent evolution coinciding with emergence of bacterial genera (e.g., Bordetella, Achromobacter). Herein, the Slc11 clade MCb is subdivided in sister groups: MCb_ie and MCb_gut. MCb_ie derives directly from the Slc11 clade MCa, pointing an intermediate stage in the evolution of MCb_gut. MCb_ie predominates in marine Bacillaceae, is more conserved than MCb_gut, lacks the structural plasticity that typify MCb_gut carriers, and responds differently to identical mutagenesis. Exchanging MCb_ie/MCb_gut amino acid residues at sites that distinguish these clades showed conformation-dependent effects with both MCb_ie and MCb_gut templates, and the 3D location of the targeted sites in the carrier structure together suggests that the mechanism to open the inner gate, and release Mn into the cytoplasm, differs between MCb_ie and MCb_gut. Building on the established phylogeny for Enterococcus revealed that a pair of genes encoding MCb_gut was present in the common ancestor of LB, as MCb_gu1 and MCb_gu2 templates exhibited distinct structural dynamics properties. These data are discussed when examining whether MCb_gut⁺ LB could emerge in the upper gut of early vertebrates (ca. 540 mya), through genome contraction and evolution toward Mn-centrism, as they specialized as gastric aids favoring stomach establishment in jawed vertebrates through bi-directional communication with host nervous, endocrine and immune systems. Full article

Oral health remains one of the most taken for granted parts of human body health, even though poor oral health has now been linked to various diseases, such as cancers, diabetes, autoimmune complications, neurological disorders, and cardiovascular disease, just to name a few. As we review in this paper, substance use or abuse, including alcohol, smoking, recreational drugs, and pharmaceutical drugs can have significant implications on oral health, which in turn can lead to more systemic diseases. In this paper, we show that oral microbiome dysbiosis and inflammatory cytokine pathways are two of the most significant mechanisms contributing to oral health complications from substance use. When substance use decreases beneficial oral species and increases periodontopathogenic strains, a subsequent cascade of oncogenic and inflammatory cytokines is triggered. In this review, we explore these mechanisms and others to determine the consequences of substance use on oral health. The findings are of significance clinically and in research fields as the substance-use-induced deterioration of oral health significantly reduces quality of life and daily functions. Overall, the studies in this review may provide valuable information for future personalized medicine and safer alternatives to legal and pharmaceutical substances. Furthermore, they can lead towards better rehabilitation or preventative initiatives and policies, as it is critical for healthcare and addiction aid specialists to have proper tools at their disposal. Full article

According to the World Health Organization (WHO), tuberculosis (TB) remains a significant global health challenge, with approximately 10 million new cases and 1.4 million deaths reported in 2020. TB disproportionately affects low- and middle-income countries, where factors such as migrant population, malnutrition, type 2 diabetes, human immunodeficiency virus (HIV) co-infection, and COVID-19 exacerbate its impact. TB also leads to substantial economic losses due to decreased productivity and high healthcare costs. Despite advances in treatments, TB remains a major public health issue, particularly in poorer regions. In Mexico, TB is considered a moderate-incidence disease, with higher prevalence in border states, mainly due to population displacements. Effective TB control requires collaboration between Mexico and the United States of America given the high cross-border human movement, like in the Baja California State that reported predominantly pulmonary TB cases. Effective management of TB involves rapid diagnosis and identification of antibiotic resistance. Techniques such as PCR, high-resolution computed tomography (HRCT), and/or Xpert MTB/RIF have enhanced diagnostic accuracy. Future perspectives about TB management focus on developing new drugs and vaccines to combat drug-resistant strains, and the comorbidities associated, which must be addressed to reinforce of health public programs. Full article

This paper explores the intriguing parallels between bacterial behavior and human actions, specifically the tendency of bacteria to adhere to surfaces, construct bacterial “houses” known as a biofilm matrix, nurture growth and reproduction within the biofilm matrix, and disperse upon maturity. Termed as the bacterial “houses”, biofilm matrices exert significant influence on various aspects of human life. A well-structured biofilm matrix serves as the foundation for establishing biofilm reactors capable of efficiently removing heavy metal pollutants from water. Conversely, a dysfunctional biofilm matrix can lead to infections and subsequent illnesses in the human body. Therefore, the study of the biofilm matrix emerges as pivotal. Employing a bibliographic study methodology, this paper analyzes 1000 web of science articles in the field, investigating key keywords, influential countries/regions, organizations, and their interconnections. The findings illuminate the primary themes in biofilm matrix research and offer insights into future directions for this critical field of study. Full article

Antimicrobial resistance is a significant public health issue. The unprecedented spread of antimicrobial-resistant organisms has been identified by the World Health Organization as one of the leading healthcare threats. Projections for annual worldwide deaths attributed to antimicrobial resistance approach 10 million by 2050, with an associated economic burden of USD 100 trillion. This paper reviews the mechanisms known to contribute to antimicrobial resistance and provides insight into potential available alternatives to conventional antibiotics. Antimicrobial approaches addressed include dual antibiotic therapy, antimicrobial peptides, monoclonal antibodies, bacteriophages, probiotics, nanomaterials, and cannabinoids. Key pathogens in need of antimicrobials referred to as the ESKAPE pathogens are discussed. Full article

Background: Several Acinetobacter species live in different ecosystems, such as soil, freshwater, wastewater, and solid wastes, which has attracted considerable research interests in public health and agriculture. Methods: We assessed the distribution of Acinetobacter baumannii and Acinetobacter nosocomialis in three freshwater resources (Great Fish, Keiskemma, and Tyhume rivers) in South Africa between April 2017–March 2018. Molecular identification of Acinetobacter species was performed using Acinetobacter-specific primers targeting the recA gene, whilst confirmed species were further delineated into A. baumannii and A. nosocomialis. Similarly, virulence genes; afa/draBC, epsA, fimH, OmpA, PAI, sfa/focDE, and traT in the two Acinetobacter species were assessed. Results: Our finding revealed that 410 (48.58%) and 23 (2.7%) of the isolates were confirmed as A. baumannii and A. nosocomalis, respectively. Additionally, three hundred and eight (75.12%) A. baumannii and three (13.04%) A. nosocomialis exhibited one or more of the virulence genes among the seven tested. OmpA was the most prevalent virulence gene in A. baumannii in freshwater sources. Conclusions: The distribution of clinically important Acinetobacter species in the freshwater sources studied suggests possible contamination such as the release of hospital wastewater and other clinical wastes into the environment thereby posing a risk to public health. Full article

It is imperative to say that we are immersed in a sea of microorganisms due to their ubiquitous presence on the planet, from soil to water and air. Human bodies harbor a vast array of microorganisms from both the inside and out called the human microbiome. It is composed of single-celled organisms, including archaea, fungi, viruses, and bacteria, including bacteriophages, where bacteria are the biggest players, and this is collectively referred to as the human microbiome. These organisms have a symbiotic relationship with humans and impact human physiology where they colonize various sites on and in the human body, adapting to specific features of each niche. However, dysbiosis, or the deviation from normal microbial composition, is associated with adverse health effects, disrupted ecosystems, and eco-imbalance in nature. In this review, we delve into the comprehensive oversight of bacteria, their cosmopolitan presence, and their additional applications affecting human lives. Full article