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Chaetoceros muelleri and Isochrysis zhanjiangensis, known for their rapid reproduction, small size, and rich nutritional content, are commonly used as feed microalgae in aquaculture. This study aimed to sterilize these microalgal species and assess the effects of antibiotics on their algal cell density. Phycospheric bacteria were isolated and identified using the spread plate method and 16S rDNA sequencing, and antibiotic susceptibility tests were conducted using four antibiotics: ampicillin, streptomycin, kanamycin, and gentamicin sulfate. A sterile system was established for C. muelleri using ampicillin, streptomycin, and gentamicin, and for I. zhanjiangensis using kanamycin, ampicillin, and streptomycin. Based on the results, antibiotics with sterilization effects were selected and added to the algal cultures. Their effects on cell density were evaluated during a six-day co-culture. Ampicillin and streptomycin effectively inhibited bacteria associated with C. muelleri, initially increasing algal cell density but later causing a decline. For I. zhanjiangensis, kanamycin and ampicillin were effective, with kanamycin significantly promoting growth throughout the cycle, achieving a 36.92% higher cell density on day six (p < 0.05). [ABSTRACT FROM AUTHOR]

Antibiotic therapy has been a common method for treating bacterial infections over the past century, but with the rise in bacterial resistance caused by antibiotic abuse, better control and more rational use of antibiotics have been increasingly demanded. At the same time, a journey to explore alternatives to antibiotic therapies has also been undertaken. Chitosan and its derivatives, materials with good biocompatibility, biodegradability, and excellent antibacterial properties, have garnered significant attention, and more and more studies on chitosan and its derivatives have been conducted in recent years. In this work, we aim to elucidate the biological properties of chitosan and its derivatives and to track their clinical applications, as well as to propose issues that need to be addressed and possible solutions to further their future development and application. [ABSTRACT FROM AUTHOR]

This review aimed to identify newly discovered bacteria from individuals with periodontal/peri-implant diseases and organize them into new clusters (GF-MoR complexes) to update Socransky's complexes (1998). For methodological development, the PCC (Population, Concept, Context) strategy was used for the focus question construction: "In patients with periodontal and/or peri-implant disease, what bacteria (microorganisms) were detected through laboratory assays?" The search strategy was applied to PubMed/MEDLINE, PubMed Central, and Embase. The search key terms, combined with Boolean markers, were (1) bacteria, (2) microbiome, (3) microorganisms, (4) biofilm, (5) niche, (6) native bacteria, (7) gingivitis), (8) periodontitis, (9) peri-implant mucositis, and (10) peri-implantitis. The search was restricted to the period 1998–2024 and the English language. The bacteria groups in the oral cavity obtained/found were retrieved and included in the GF-MoR complexes, which were based on the disease/condition, presenting six groups: (1) health, (2) gingivitis, (3) peri-implant mucositis, (4) periodontitis, (5) peri-implantitis, and (6) necrotizing and molar–incisor (M-O) pattern periodontitis. The percentual found per group refers to the number of times a specific bacterium was found to be associated with a particular disease. A total of 381 articles were found: 162 articles were eligible for full-text reading (k = 0.92). Of these articles, nine were excluded with justification, and 153 were included in this review (k = 0.98). Most of the studies reported results for the health condition, periodontitis, and peri-implantitis (3 out of 6 GF-MoR clusters), limiting the number of bacteria found in the other groups. Therefore, it became essential to understand that bacterial colonization is a dynamic process, and the bacteria present in one group could also be present in others, such as those observed with the bacteria found in all groups (Porphyromonas gingivalis, Tannarela forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) (GF-MoR's red triangle). The second most observed bacteria were grouped in GF-MoR's blue triangle: Porphyromonas spp., Prevotela spp., and Treponema spp., which were present in five of the six groups. The third most detected bacteria were clustered in the grey polygon (GF-MoR's grey polygon): Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens. These three geometric shapes had the most relevant bacteria to periodontal and peri-implant diseases. Specifically, per group, GF-MoR's health group had 58 species; GF-MoR's gingivitis group presented 16 bacteria; GF-MoR's peri-implant mucositis included 17 bacteria; GF-MoR's periodontitis group had 101 different bacteria; GF-MoR's peri-implantitis presented 61 bacteria; and the last group was a combination of necrotizing diseases and molar–incisor (M-I) pattern periodontitis, with seven bacteria. After observing the top seven bacteria of all groups, all of them were found to be gram-negative. Groups 4 and 5 (periodontitis and peri-implantitis) presented the same top seven bacteria. For the first time in the literature, GF-MoR's complexes were presented, gathering bacteria data according to the condition found and including more bacteria than in Socransky's complexes. Based on this understanding, this study could drive future research into treatment options for periodontal and peri-implant diseases, guiding future studies and collaborations to prevent and worsen systemic conditions. Moreover, it permits the debate about the evolution of bacterial clusters. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to identify the pathogen responsible for leaf blight in Cyclocodon lancifolius, investigate its biological characteristics, and identify effective synthetic fungicides. Additionally, this study examined changes in physiological and biochemical indices of leaves following pathogen infection and screened biocontrol bacteria that inhibit the pathogen growth, providing a scientific basis for preventing and managing leaf blight in C. lancifolius. Methods: Pathogens were isolated from the interface of healthy and infected leaf tissues and identified through morphological and molecular biological methods. Amplification and sequencing of three genomic DNA regions--internal transcribed spacer region, translation elongation factor 1-a, and glyceraldehyde-3-phosphate dehydrogenase of ribosomal DNA--were performed, followed by the construction of a phylogenetic tree. The biological characteristics of pathogens under various temperature and pH conditions and different nitrogen and carbon sources were analyzed using the mycelial growth rate method. The antifungal effects of 13 chemical agents were evaluated using the poisoned medium method and mycelial growth rate method. Changes in physiological and biochemical indicators post-infection were also assessed. An antagonistic experiment was conducted to screen for biocontrol bacteria. Results: A total of 29 potential pathogenic strains were isolated from infected leaf tissues, with Koch's Postulates confirming Stemphylium lycopersici as a key pathogen causing the disease. Growth analysis of S. lycopersici revealed optimal growth at 20°C and pH 6, with lactose or maltose serving as the most suitable carbon source and histidine as the preferred nitrogen source. Among the 13 synthetic fungicides tested, strain DHY4 exhibited the greatest sensitivity to 400 g/L flusilazole. Significant differences (p < 0.05) were observed in superoxide dismutase, phenylalanine ammonia-lyase, peroxidase, polyphenol oxidase, catalase, and malondialdehyde levels between treated and control groups 3 days post-inoculation. The biocontrol strain DYHS2, identified as a strain of Bacillus subtilis, demonstrated an inhibition rate of 51.80% against S. lycopersici in dual-culture experiments and showed a relative inhibition rate of 78.82% in detached leaf assays. Discussion: These findings provide valuable insights into the newly identified causal agent of leaf blight in C. lancifolius and its biological characteristics, underscoring the potential of B. subtilis DYHS2 and synthetic fungicides such as flusilazole as effective disease management strategies. [ABSTRACT FROM AUTHOR]

Abstract Purpose Rot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. Methods The disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. Results The findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. Conclusion These findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development.

Purpose: Rot disease caused by Fusarium poses a formidable threat to the growth of saffron (Crocus sativus L.), resulting in substantial damage to both yield and quality. It is paramount to delve into the root causes of rot disease in saffron to optimize both yield and quality. Existing preventive and treatment modalities have exerted deleterious effects on corms and the natural environment. Consequently, the quest for efficacious and eco-friendly methods such as biological control agents has become an urgent imperative. Methods: The disparate distribution of microbial communities between rhizospheric microorganisms and saffron serves as the foundational exploration for uncovering the underlying causes of rot disease. Samples from various saffron organs and rhizosphere soil were gathered, and the sequencing data from the microbial communities were interpreted using 16S rRNA and ITS gene sequencing methods. This facilitated an in-depth examination of the composition and changes of microorganisms in both healthy and diseased saffron plants. Results: The findings indicated rot disease reduced the abundance and diversity of microorganisms in saffron, and the fungal co-occurrence networks were less stable and their communities were more sensitive to rot disease than the bacterial community. Fusarium was the predominant genus in diseased samples, accounting for 99.19% and 89.77% of the communities in diseased leaves and corms. With corms and leaves displaying heightened susceptibility to infection compared to other plant organs. Some of the beneficial bacterial taxa enriched in the diseased plants were also identified in networks, they showed an antagonistic relationship with Fusarium, suggesting a potential for these bacteria to be used in biologically based control strategies against rot disease. These insights could prove invaluable for the development of biocontrol agents aimed at combating this plant ailment. Conclusion: These findings significantly advance our understanding of saffron-microbiome interactions and could provide fundamental and important data for improving saffron yield and quality in the process of sustainable development. [ABSTRACT FROM AUTHOR]

Simple Summary: There are differences in the cold resistance and anti-freeze compound levels in the two sexes of Pardosa astrigera, driving us to explore the differences in their intestinal microbiome. In this study, intestinal bacterial communities of P. astrigera in winter were compared using 16S rRNA high-throughput sequencing. The results showed significant differences in most alpha diversity indices and the relative abundances of dominant bacteria between males and females. Our research reveals the significant role of sex in shaping the diversity and composition of intestinal bacteria in overwintering P. astrigera. We suggest that Pseudomonas versuta (belonging to Proteobacteria) and Rhodococcus erythropolis (belonging to Actinobacteriota) may have the potential to play key roles in overwintering P. astrigera. Gut microbiota can promote the resistance of host arthropods to low-temperature stress. Female Pardosa astrigera have a lower anti-freeze compound level and weaker resistance to cold temperatures than the males in winter, which implies that their intestinal bacteria may be different during overwintering. This study primarily compared the intestinal bacterial communities between the two sexes of P. astrigera in a temperate region using 16S rRNA gene sequencing. Our findings indicated that the Chao1 and Shannon indices of intestinal bacteria in females were significantly higher than those in males, while the Simpson index in females was significantly lower than that in males. The male intestinal bacterial community was characterized by Proteobacteria and Actinobacteriota at the phylum level and by Pseudomonas and Rhodococcus at the genus level, with total relative abundances of 89.58% and 85.22%, respectively, which were also significantly higher than those in females, whose total relative abundances were 47.49% and 43.68%, respectively. In contrast, the total relative abundances of Bacteroidota and Firmicutes were significantly lower in males (4.26% and 4.75%, respectively) than in females (26.25% and 22.31%, respectively). Noteworthy divergences in bacterial communities were also found through an LEfSe analysis between females and males. Additionally, the results of the PICRUSt2 analysis showed that six out of eleven level-2 pathways related to key metabolic functions were significantly (or marginally significantly) higher in females than males, and five other level-2 pathways were significantly (or marginally significantly) lower in females than males. Our results imply that significant gender differences exist in intestinal bacterial communities of overwintering P. astrigera. We suggest that Pseudomonas versuta (belonging to Proteobacteria) and Rhodococcus erythropolis (belonging to Actinobacteriota) may have the potential to play key roles in overwintering P. astrigera. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB), a grave infectious disease affecting millions globally, is often diagnosed using chest X-rays. For accurate diagnosis, especially for detecting early stage, medical practitioners require the assistance of advanced technologies. In contrast to existing models, which focus largely on TB detection in the images, the proposed work aims to classify the images affecting TB such that an appropriate method can be chosen for accurate chest TB detection in chest X-ray images. Thus, we aim to combine the powerful features of the VGG16 architecture with a convolutional neural network (CNN) for classification purposes. Drawing inspiration from VGG16, known for its effective method of capturing essential image information, we aim to modify VGG16 for feature extraction to identify signs of tuberculosis (TB) in images. For the classification task, we employ a CNN to categorize images impacted by TB. Our proposed technique is evaluated on a standard dataset, demonstrating its superiority over current leading methods in accuracy, recall, and precision. [ABSTRACT FROM AUTHOR]

ABSTRACT A major factor limiting the biodegradation of organofluorine compounds has been highlighted as fluoride anion toxicity produced by defluorinating enzymes. Here, two highly active defluorinases with different activities were constitutively expressed in Pseudomonas putida ATCC 12633 to examine adaption to fluoride stress. Each strain was grown on α‐fluorophenylacetic acid as the sole carbon source via defluorination to mandelic acid, and each showed immediate fluoride release and delayed growth. Adaptive evolution was performed for each recombinant strain by serial transfer. Both strains adapted to show a much shorter lag and a higher growth yield. The observed adaptation occurred rapidly and reproducibly, within 50 generations each time. After adaption, growth with 50–70 mM α‐fluorophenylacetic acid was significantly faster with more fluoride release than a preadapted culture due to larger cell populations. Genomic sequencing of both pre‐ and postadapted strain pairs revealed decreases in the defluorinase gene content. With both defluorinases, adaption produced a 56%–57% decrease in the plasmid copy number. Additionally, during adaption of the strain expressing the faster defluorinase, two plasmids were present: the original and a derivative in which the defluorinase gene was deleted. An examination of the enzyme rates in the pathway suggested that the defluorinase rate was concurrently optimised for pathway flux and minimising fluoride toxicity. The rapid alteration of plasmid copy number and mutation was consistent with other studies on microbial responses to stresses such as antibiotics. The data presented here support the idea that fluoride stress is significant during the biodegradation of organofluorine compounds and suggest engineered strains will be under strong selective pressure to decrease fluoride stress.

ABSTRACT Antimicrobials are pivotal in treating bacterial infections. More often than any other class of antimicrobial, antibiotics are a class of antimicrobials used primarily to treat bacterial infections. Thus, both human health and life longevity, as well as the welfare of animals, have greatly improved with the development of antibiotics as a means of treating infectious diseases. Dairy farming is essential to satisfying the world's demand for dairy products. Nevertheless, improper use of antibiotics in dairy farming contributes greatly to the formation of antimicrobial resistance. Moreover, the resulting antimicrobial resistance can be transferred to humans by consuming contaminated dairy products. Therefore, the scientific community has been intensively studying the relationship between dairy farming and antimicrobial resistance since 1983. And, due to the increasing awareness of antimicrobial resistance worldwide, studies on antimicrobial resistance in dairy farming have rapidly increased 89 times in the last twenty years. Today, the development of antimicrobial resistance in dairy farming is among the trending research topics. For this purpose, this study is the first bibliometric approach that aims to guide future studies by revealing all aspects of the studies on this subject between 1983 and 2023.

The magnetotactic bacterium MO-1 possesses a pair of unique flagellar apparatuses. Each apparatus comprises seven flagella and 24 thin fibrils enclosed in a sheath. Using these apparatuses, the cells swim at high speed through solutions, tracing helical trajectories. The mechanism by which MO-1 cells utilize their two flagellar apparatuses to propel the cell body remains unclear. Due to the short length of the flagellar apparatus, direct observation of individual movements under a microscope is technically challenging. In this study, we performed numerical simulations based on the boundary element method to investigate the swimming motility of MO-1 cells. Our cell models successfully reproduced the helical trajectories of active MO-1 cells. The two flagellar apparatuses were positioned at the front and back of the cell body relative to the direction of movement. The cell body was pulled by the anterior flagellar apparatus and pushed by the posterior apparatus. The swimming motion of the cell model exhibited minimal changes near a wall. This unique swimming behavior of MO-1 cells could only be achieved through the rotation of both flagellar apparatuses. Based on the revolution rate of active MO-1 cells, we estimated the rotational speed of the flagellar apparatus to be approximately 1200 s-1. This rapid rotation may result from the tight packing of flagellar filaments within the sheath. Our study elucidates the mechanism by which active MO-1 cells swim in helical trajectories.

Introduction So far, more than 40 different types of alkaloids have been known in poppy (Papaver somniferum L.) as a valuable medicinal plant, the most important of which are morphine, codeine, thebaine, noscapine, and papaverine. The biosynthesis of these alkaloids may be strongly influenced by a variety of biotic and abiotic elicitors. In fact, microbes as biotic elicitors can affect the production of poppy alkaloids. Among them, plant growth promoting rhizobacteria (PGPR) can be noticed, which stimulate and improve plant growth through various mechanisms such as mineral phosphate solubilization, plant hormone production, siderophores secretion, nitrogen fixation, etc. The use of PGPR agents can not only lead to an increase in plant biomass, but simultaneously, due to their role as biotic elicitors, they cause to an increase in the biosynthesis of secondary metabolites in plants. These biotic elicitors target plants’ defense mechanisms and result in triggering a series of metabolic changes throughout the plant. The use of PGPR agents to stimulate the plant to produce secondary metabolites has several advantages: First, in some plants, defensive metabolites are active biological compounds that lead to the induction of food production with high added-value in the plants. Secondly, physiologically, with the increase in the synthesis of secondary metabolites, the resistance of the plant against pathogens also increases. Accordingly, the present study was performed with the aim of investigating the effects of bacterial strains with the ability to solubilize inorganic phosphate as biotic elicitors on the amount of morphine, papaverine, and noscapine alkaloids in P. somniferum. Materials and Methods In this research, the solubility of inorganic phosphate by four bacterial strains including Enterobacter xiangfangensis S2, Pantoea dispersa S7, Pantoea stewartii S25, and Pseudomonas canadensis S36 was evaluated quantitatively using Sperber broth medium. Under greenhouse conditions, the effect of foliar spraying of P. somniferum plants with a suspension of the bacterial strains (108 CFU.ml-1) on the amount of morphine, papaverine, and noscapine in the plants’ capsules, stems, and leaves was investigated. About three weeks after the appearance of capsules in poppy plants, the aerial parts of the plants (stems, leaves, and capsules) were sprayed with the bacterial suspensions. One week after foliar spraying, poppy plants were harvested in order to determine the amount of the desired alkaloids. Three pots were considered for each treatment and there were three poppy plants in each pot. Alkaloids were extracted based on an alcoholic method and detected using HPLC. Morphine and noscapine standards were prepared at a concentration of 1000 μg.ml-1 and papaverine standard at a concentration of 250 μg/ml. Then the mixture was prepared in proportions of 1, 1:50, 1:10, 1:50 and 1:100 and injected into the HPLC set to draw the calibration curve. All the experiments were conducted in a form of completely randomized design with three replications for each treatment (P

The study aimed to assess the prevalence of COVID-19 and Klebsiella spp. coinfection across continents. Conducted following PRISMA guidelines, a systematic review utilized PubMed, Embase, SCOPUS, ScienceDirect, and Web of Science databases, searching for literature in English published from December 2019 to December 2022, using specific Health Sciences descriptors. A total of 408 records were identified, but only 50 were eligible, and of these, only 33 were included. Thirty-three references were analyzed to evaluate the correlation between COVID-19 and Klebsiella spp. infections. The tabulated data represented a sample group of 8741 coinfected patients. The findings revealed notable disparities in co-infection rates across continents. In Asia, 23% of individuals were infected with Klebsiella pneumoniae, while in Europe, the proportion of co-infected patients stood at 15%. Strikingly, on the African continent, 43% were found to be infected with Klebsiella pneumoniae, highlighting significant regional variations. Overall, the proportion of Klebsiella pneumoniae co-infections among COVID-positive individuals were determined to be 19%. Particularly concerning was the observation that 1 in 6 ICU coinfections was attributed to Klebsiella pneumoniae, indicating its substantial impact on patient outcomes and healthcare burden. The study underscores the alarming prevalence of co-infection between COVID-19 and Klebsiella pneumoniae, potentially exacerbating the clinical severity of patients and posing challenges to treatment strategies. These findings emphasize the importance of vigilant surveillance and targeted interventions to mitigate the adverse effects of bacterial coinfections in the context of the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Eutrophication of aquatic ecosystems is associated with an increased risk of pathogen infection via increased pathogen growth and host exposure via increased pathogen doses. Here, we studied the effect of nutrients on the virulence of an opportunistic bacterial pathogen of fish, Flavobacterium columnare , in challenge experiments with rainbow trout fingerlings. We hypothesized that removing all nutrients by washing the bacteria would reduce virulence as compared to unwashed bacteria, but adding nutrients to the tank water would increase the virulence of the bacterium. Nutrient addition and increase in bacterial dose increased virulence for both unwashed and washed bacteria. For unwashed bacteria, the addition of nutrients reduced the survival probability of fish challenged with low bacterial doses more than for fish challenged with higher bacterial doses, suggesting activation of bacterial virulence factors. Washing and centrifugation reduced viable bacterial counts, and the addition of washed bacteria alone did not lead to fish mortality. However, a small addition of nutrient medium, 0.05% of the total water volume, added separately to the fish container, restored the virulence of the washed bacteria. Our results show that human-induced eutrophication could trigger epidemics of aquatic pathogens at the limits of their survival and affect their ecology and evolution by altering the dynamics between strains that differ in their growth characteristics. [ABSTRACT FROM AUTHOR]

IntroductionAir flow driven by air-conditioner has a significant impact on the indoor environment, however, the bacterial contamination conditions in the different parts of air-conditioners have not been fully elucidated.MethodsIn this study, we assessed the bacterial pollution in the four parts, including air outlet, filter net, cooling fin and water sink, of ten household air-conditioners quantitatively and qualitatively from Chengdu, southwestern China.ResultsThe microbial cultivation results showed the large total bacterial counts of 5042.0, 9127.6, 6595.1, and 12296.2 CFU/cm2 in air outlet, filter net, cooling fin, and water sink. Furthermore, the sequencing data showed that these four parts displayed different bacterial characteristics. At the level of genus, Caproiciproducens and Acidipropionibacterium were predominant in air outlet. Bacillus, Acinetobacter, Paracoccus, and Corynebacterium were detected as the characteristic bacteria in filter net. For cooling fin, Rhodococcus, Achromobacter, and Nocardioides were the dominant bacteria. The genera of Methylobacterium-Methylorubrum, Brevibacterium, Stenotrophomonas, and Psychrobacter were identified as the bioindicators in water sink. The bioinformatic analysis on the sequencing data illustrated that the bacteria from air-conditioners were associated with metabolic disturbance.DiscussionThis study reveals the distinct bacterial compositions in the different parts of air-conditioner, and provides new clues for the non-negligible bacterial pollution in this common appliance from Chinese households.

In order to investigate the microbial community structure in air of different regions of strong-flavor (Nongxiangxing) Baijiu distillery, the microbial community structure and distribution in air of Baotuquan strong-flavor distillery, outside and inside the brewing workshop were studied by Illumina Miseq high-throughput sequencing technology. The results showed that the microbial community in the air samples of distillery was the richest and the highest in diversity, while the diversity in the brewing workshop was low, indicating that in the long-term brewing process, the microorganisms that were not suitable for the brewing environment were eliminated after continuous screening, and a relatively stable microbial flora suitable for the environment was formed by the appropriate microbial enrichment. A total of 748 bacterial operational taxonomic units (OTUs) and 340 fungal OTUs were detected in all the air samples. A total of 20 bacterial phyla and 289 bacterial genera and 7 fungal phyla and 149 fungal genera were noted. The bacterial community in the air samples of different distillery areas was different, while the similarity of the fungal community was high. Compared with the microorganism in air samples of distillery, the microbial communities inside and outside the brewing workshop were more similar. In addition, the unique microbial communities such as Paracococcus were found in the brewing workshop of strong-flavor Baijiu brewed by mechanization.

This review aimed to identify newly discovered bacteria from individuals with periodontal/peri-implant diseases and organize them into new clusters (GF-MoR complexes) to update Socransky’s complexes (1998). For methodological development, the PCC (Population, Concept, Context) strategy was used for the focus question construction: “In patients with periodontal and/or peri-implant disease, what bacteria (microorganisms) were detected through laboratory assays?” The search strategy was applied to PubMed/MEDLINE, PubMed Central, and Embase. The search key terms, combined with Boolean markers, were (1) bacteria, (2) microbiome, (3) microorganisms, (4) biofilm, (5) niche, (6) native bacteria, (7) gingivitis), (8) periodontitis, (9) peri-implant mucositis, and (10) peri-implantitis. The search was restricted to the period 1998–2024 and the English language. The bacteria groups in the oral cavity obtained/found were retrieved and included in the GF-MoR complexes, which were based on the disease/condition, presenting six groups: (1) health, (2) gingivitis, (3) peri-implant mucositis, (4) periodontitis, (5) peri-implantitis, and (6) necrotizing and molar–incisor (M-O) pattern periodontitis. The percentual found per group refers to the number of times a specific bacterium was found to be associated with a particular disease. A total of 381 articles were found: 162 articles were eligible for full-text reading (k = 0.92). Of these articles, nine were excluded with justification, and 153 were included in this review (k = 0.98). Most of the studies reported results for the health condition, periodontitis, and peri-implantitis (3 out of 6 GF-MoR clusters), limiting the number of bacteria found in the other groups. Therefore, it became essential to understand that bacterial colonization is a dynamic process, and the bacteria present in one group could also be present in others, such as those observed with the bacteria found in all groups (Porphyromonas gingivalis, Tannarela forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) (GF-MoR’s red triangle). The second most observed bacteria were grouped in GF-MoR’s blue triangle: Porphyromonas spp., Prevotela spp., and Treponema spp., which were present in five of the six groups. The third most detected bacteria were clustered in the grey polygon (GF-MoR’s grey polygon): Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens. These three geometric shapes had the most relevant bacteria to periodontal and peri-implant diseases. Specifically, per group, GF-MoR’s health group had 58 species; GF-MoR’s gingivitis group presented 16 bacteria; GF-MoR’s peri-implant mucositis included 17 bacteria; GF-MoR’s periodontitis group had 101 different bacteria; GF-MoR’s peri-implantitis presented 61 bacteria; and the last group was a combination of necrotizing diseases and molar–incisor (M-I) pattern periodontitis, with seven bacteria. After observing the top seven bacteria of all groups, all of them were found to be gram-negative. Groups 4 and 5 (periodontitis and peri-implantitis) presented the same top seven bacteria. For the first time in the literature, GF-MoR’s complexes were presented, gathering bacteria data according to the condition found and including more bacteria than in Socransky’s complexes. Based on this understanding, this study could drive future research into treatment options for periodontal and peri-implant diseases, guiding future studies and collaborations to prevent and worsen systemic conditions. Moreover, it permits the debate about the evolution of bacterial clusters.

Bacteria regulate their cellular resource allocation to enable fast growth-adaptation to a variety of environmental niches. We studied the ribosomal allocation, growth, and expression profiles of two sets of fast-growing mutants of Escherichia coli K-12 MG1655. Mutants with only three of the seven copies of ribosomal RNA operons grew faster than the wild-type strain in minimal media and show similar phenotype to previously studied fast-growing rpoB mutants. Comparing these two different regulatory perturbations (rRNA promoters or rpoB mutations), we show how they reshape the proteome for growth with a concomitant fitness cost. The fast-growing mutants shared downregulation of hedging functions and upregulated growth functions. They showed longer diauxic shifts and reduced activity of gluconeogenic promoters during glucose-acetate shifts, suggesting reduced availability of the RNA polymerase for expressing hedging proteome. These results show that the regulation of ribosomal allocation underlies the growth/hedging phenotypes obtained from laboratory evolution experiments.

Background and Aim: The rapid development of aquaculture as a major food sector is accompanied by challenges, including diseases that affect tilapia farming worldwide. One such infectious disease caused by Streptococcus agalactiae poses a serious threat to tilapia populations. Probiotics have emerged as a potentially safe preventive measure against S. agalactiae infection. However, antimicrobial resistance from antibiotic-resistant bacteria remains a concern because it can lead to the spread of resistant bacteria and serve as a reservoir of antibiotic-resistant genes in fishes and the surrounding environment. This study aimed to identify candidate probiotic bacteria capable of promoting tilapia growth, providing resistance to S. agalactiae infection, devoid of potential pathogenicity, and free from antibiotic resistance genes. Subsequently, the performance of these probiotic candidates in tilapia was evaluated. Materials and Methods: Lactococcus garvieae, Priestia megaterium, Bacterium spp., Bacillus megaterium, Bacillus subtilis, and Bacillus pumilus were examined to assess their antibacterial properties, hemolytic patterns, and antibiotic resistance genes. We used the specific primers tetA, tetB, tetD, tetE, tetO, tetQ, ermB, and qnrS that were used for antibiotic resistance gene detection. In vivo probiotic efficacy was evaluated by administering probiotic candidates in tilapia feed at a concentration of 1 × 106 colonies/mL/50 g of feed over a 60-day maintenance period. Resistance to S. agalactiae infection was observed for 14 days after the challenge test. Results: Lactococcus garvieae, P. megaterium, and Bacterium spp. were identified as promising probiotic candidates among the bacterial isolates. On the other hand, B. megaterium, B. subtilis, and B. pumilus carried resistance genes and exhibited a β hemolytic pattern, rendering them unsuitable as probiotic candidates. The selected probiotic candidates (L. garvieae, P. megaterium, and Bacterium spp.) demonstrated the potential to enhance tilapia growth, exhibited no pathogenic tendencies, and were free from antibiotic resistance genes. Supplementation with L. garvieae and Bacterium spp. enhanced tilapia resistance to S. agalactiae infection, whereas P. megaterium supplementation showed an insignificant survival rate compared with controls after the challenge test period. Conclusion: Probiotics, particularly L. garvieae, P. megaterium, and Bacterium spp., enhance growth and resistance against S. agalactiae infection, without harboring antibiotic resistance genes. Selecting probiotic candidates based on antibiotic resistance genes is essential to ensure the safety of fish, the environment, and human health.

It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However, this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg.

Ventilator associated pneumonia (VAP) is an infectious disease in clinic with high incidence rate (about 5%-40%) and mortality (about 10%), which is mainly caused by bacteria. At present, the clinical diagnosis of VAP depends on the microbial pathogen diagnosis of sputum samples from the lower respiratory tract. The whole process takes more than 24 hours, which is easy to cause antibiotic misuse and initial treatment failure. In recent years, breath test has received widespread attention due to its non-invasive and convenient characteristics, which attempt to screen and diagnose VAP through analysis of volatile organic compounds (VOCs) in exhalation. Therefore, the research on characterization of VOCs released by VAP pathogens has certain guiding significance for the related breath tests. In this study, the main VAP pathogenic bacteria, including P. aeruginosa, S. aureus, E. coli, E. cloacae, K. pneumoniae, A. baumannii, S. maltophilia, and S. epidermidis, were cultured in tryptic soy broth (TSB) culture medium in vitro, and their headspace samples were obtained after 10 hours of shaking culture. Then, non-targeted detection of VOCs in the headspace was performed by using solid phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC-MS). It was found that a total of 44 differential amounts of VOCs were released by the 8 strains. Subsequently, these bacterial VOCs were classified and discussed according to ketones, aldehydes, ethers, alcohols, acids, esters, alkanes, benzenes, amides, and (nitrogen-containing) heterocycles. These results showed that there was some consistency in the types of VOCs released by the 8 VAP pathogens, such as the production of dimethyl ether and methyl mercaptan. However, there were some differences in the released VOCs among the different pathogens. For example, only S. aureus released 2-butanone and 3-hydroxy-2-butanone, only E. coli produced acetic acid, only E. coli, S. maltophilia, and S. aureus produced N-nenenebc methylformamide. In addition, K. pneumoniae and P. aeruginosa released dimethyl disulfide (DMDS), and S. maltophilia released dimethyl trisulfide (DMTS). This study systematically reports the similarities and differences in the types of VOCs released by VAP pathogens, providing a reference and foundament for VAP related breath research. In the future, it is expected to achieve rapid and non-invasive screening of VAP through exhalation. However, this study did not detect clinically isolated strains or samples, and it was not possible to verify whether there were any differences in results between standard strains and clinical strains. In future work, it is necessary to consider the characteristic spectra of clinically isolated strains and the landmark VOCs in the exhalation of clinical patients.

The effectiveness of two biological control agents, Chrysoperla carnea (Neuroptera: Chrysopidae) and the entomopatho­genic fungus Beauveria bassiana (Ascomycota: Hypocreales) against nymphs and adults of Neophilaenus campestris (Hemi­ptera: Aphrophoridae) was determined under laboratory conditions. First, different nymphal stages of N. campestris were presented to different larval stages of C. carnea. Second, the effect of the foam produced by N. campestris nymphs on the larvae of C. carnea predation was evaluated. Finally, four concentrations of a wild strain of B. bassiana, BbGEp1, were sprayed on plants in order to determine their lethality for adults of N. campestris. Second and 3rd-instar larvae of green lacewing larvae are capable of capturing and killing 3rd and 5th-instar nymphs of N. campestris. The percentage of 3rd-instar lacewing larvae that killed nymphs was significantly higher than that were killed by second-instar larvae. Second-instar larvae killed significantly more 3rd-instar nymphs than 5th-instar nymphs. Third instar lacewing larvae killed an average (± SEM) of 1.50 ± 0.31 5th-instar nymphs and 2nd-instar larvae killed very few nymphs. Spittlebug foam reduced, but did not prevent predation. The lethality of the entomopathogenic B. bassiana BbGEp1 used against adults of N. campestris was characterized by an LC50 value of 1.61 × 106 conidia/mL and LT50 of 3.63 days at 1 × 107 conidia/mL. The present study provides new and valuable data on the activity of two promising biological control agents of vectors of the bacterium Xylella fastidiosa. Further research is needed to confirm the results presented here and on the cost effectiveness of using these control agents as alternatives to synthetic insecticides for preventing the further spread of X. fastidiosa in Europe.

Chlorpyrifos, being a frequently used organophosphate pesticide poses a significant threat to human health due to its prolonged presence in soil, plants, and water, this has raised concern. Consequently, researchers have shifted their attention towards finding methods to mitigate its toxicity or eliminate it from the environment. This has highlighted the importance of bioremediation. This study was aimed at analyzing and characterizing the metabolites of chlorpyrifos degradation by Bacillus sp. strain UPMB10 isolated from polluted environment using Gas Chromatography-Mass Spectrometry. The bacteria were successfully isolated utilizing the enrichment technique in mineral salt media, followed by screening to obtain the best isolate. Identification of the isolate was done at morphological, biochemical, and molecular levels, with a focus on the 16S rRNA gene. Phylogenetic analysis revealed the close relationship between the bacterium and Bacillus sp. strain UPMB10. Optimization (One Factor at A Time) was done to determine best growth conditions of the isolate. The optimal growth conditions obtained include, incubation time of 48 hours, a substrate concentration of 4 g/L, a pH of 7.0, a temperature of 37 °C, and an inoculum size of 2 % (v/v), these quantitative data revealed valuable insights into the factors affecting efficient degradation of pesticide. Gas Chromatography-Mass Spectrometry analysis demonstrated that the bacterium achieved a remarkable degradation efficiency of 99 % after 48 hours of incubation. Notably, Mesitylene and Dimethylmalonic acid were obtained as some of the metabolites of chlorpyrifos degradation. This result provides insight into the transformation of products generated during degradation process. The study finding revealed that Bacillus sp. strain UPMB10 exhibits a remarkable capacity for chlorpyrifos degradation, making it a promising candidate for bioremediation of insecticides and acaricides.

In this study, high-throughput sequencing and metabolomics analysis were conducted to analyze the microbial and metabolites of dry-cured Sanchuan ham, Laowo ham, Nuodeng ham, and Heqing ham that have fermented for two years produced from western Yunnan China. Results showed that at the genus level, the dominant bacteria in the four types of ham were Halomonas and Staphylococcus, while the dominant fungi were Aspergillus and Yamadazyma. A total 422 different metabolites were identified in four types of ham, mainly amino acids, peptides, fatty acids, and their structural analogs, which were involved in pantothenate and coenzyme A biosynthesis, caffeine, and tyrosine metabolism. The dominant microorganisms of the four types of ham were mainly related to the metabolism of fatty acids and amino acids. This research enhances the identification degree of these four types of dry-cured ham and provides a theoretical basis for developing innovative and distinctive ham products.

Avian pathogenic Escherichia coli (APEC) is responsible for several anatomopathological conditions in poultry, which cause great damage to the poultry sector. This study aimed to evaluate the pathogenicity of E. coli strains isolated from broiler chickens and to perform in vitro tests on strains classified as APEC to identify their capacity to form biofilms and sensitivity to antimicrobials routinely used in the poultry breeding process. Sixty E. coli poultry isolated were used in this study. The real-time Polymerase Chain Reaction (PCR) test identified that 100% of the isolates had the hlyF and ompT genes, 98.3% the iroN and iss genes, and 83.33% the iutA gene, being all the evaluated strains classified as APEC. In the in vitro evaluations regarding the formation and characterization of biofilms, the APEC samples were characterized as 71.66% weakly biofilm-forming. The antibiotic sensitivity test showed that the highest resistance percentages were found in the molecules of oxytetracycline, with 33%, and doxycycline, with 31.66%, but about 58,33% of the samples had a profile of multi-resistance to antimicrobials. Further studies are needed to better characterize APEC virulence genes and multi-drug resistance, given their impact on poultry health/production and potential risk to human health.

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Copyright of Revista de Ciencias Agroveterinarias is the property of Revista de Ciencias Agroveterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACTMicrobial response to toxic fluoride anion has traditionally been studied by adding inorganic fluoride salts to growth media. Fluoride is known to spontaneously transit the membrane as hydrogen fluoride (HF) and manifests significant toxicity in the cytoplasm. The present study investigated how microbes respond to high levels of HF generated directly in the cytoplasm to better understand potential limits of microbial defluorination of organofluorine compounds. For that purpose, Pseudomonas putida ATCC 12633 was engineered to express a defluorinase enzyme from Delftia acidovorans strain B that had high activity in producing growth-supporting alcohols from organofluorinated compounds of xenobiotic origin. Genome annotation predicted the growth of P. putida ATCC 12633 on all possible chiral products from 2-fluoropropionic acid and α-fluorophenylacetic acid when defluroinases are expressed. The defluorinase was shown to have complete enantioselectivity for (S)-fluoro substrates via experimental and computational modeling methods. The bacterium grew to a high turbidity with stoichiometric release of fluoride from the (S)-enantiomers into the medium. The highest yield of fluoride obtained was 50 mM with 2-fluoropropionic acid as the growth substrate. The growth yield was significantly lowered by 41% with α-fluorophenylacetic acid or 2-fluoropropionic acid compared to (S)-mandelic acid or D-lactic acid, respectively. Fluoride stress was also indicated by longer lag phases, slower growth, and cell morphology changes on fluorinated substrates or the cognate alcohols with NaF in the medium. In total, these studies show the potential for engineering bacterial defluorination of non-natural substrates within limits posed by fluoride stress.IMPORTANCESociety uses thousands of organofluorine compounds, sometimes denoted per- and polyfluoroalkyl substances (PFAS), in hundreds of products, but recent studies have shown some to manifest human and environmental health effects. As a class, they are recalcitrant to biodegradation, partly due to the paucity of fluorinated natural products to which microbes have been exposed. Another limit to PFAS biodegradation is the intracellular toxicity of fluoride anion generated from C-F bond cleavage. The present study identified a broader substrate specificity in an enzyme originally studied for its activity on the natural product fluoroacetate. A recombinant Pseudomonas expressing this enzyme was used here as a model system to better understand the limits and effects of a high level of intracellular fluoride generation. A fluoride stress response has evolved in bacteria and has been described in Pseudomonas spp. The present study is highly relevant to organofluorine compound degradation or engineered biosynthesis in which fluoride anion is a substrate.

It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However, this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg. [ABSTRACT FROM AUTHOR]

Goss's wilt, caused by the Gram-positive actinobacterium Clavibacter nebraskensis, is an important bacterial disease of maize. The molecular and genetic mechanisms of resistance to the bacterium, or, in general, Gram-positive bacteria causing plant diseases, remain poorly understood. Here, we examined the genetic basis of Goss's wilt through differential gene expression, standard genome-wide association mapping (GWAS), extreme phenotype (XP) GWAS using highly resistant (R) and highly susceptible (S) lines, and quantitative trait locus (QTL) mapping using 3 bi-parental populations, identifying 11 disease association loci. Three loci were validated using nearisogenic lines or recombinant inbred lines. Our analysis indicates that Goss's wilt resistance is highly complex and major resistance genes are not commonly present. RNA sequencing of samples separately pooled from R and S lines with or without bacterial inoculation was performed, enabling identification of common and differential gene responses in R and S lines. Based on expression, in both R and S lines, the photosynthesis pathway was silenced upon infection, while stress-responsive pathways and phytohormone pathways, namely, abscisic acid, auxin, ethylene, jasmonate, and gibberellin, were markedly activated. In addition, 65 genes showed differential responses (up- or down-regulated) to infection in R and S lines. Combining genetic mapping and transcriptional data, individual candidate genes conferring Goss's wilt resistance were identified. Collectively, aspects of the genetic architecture of Goss's wilt resistance were revealed, providing foundational data for mechanistic studies. [ABSTRACT FROM AUTHOR]

Ventilator associated pneumonia (VAP) is an infectious disease in clinic with high incidence rate (about 5%-40%) and mortality (about 10%), which is mainly caused by bacteria. At present, the clinical diagnosis of VAP depends on the microbial pathogen diagnosis of sputum samples from the lower respiratory tract. The whole process takes more than 24 hours, which is easy to cause antibiotic misuse and initial treatment failure. In recent years, breath test has received widespread attention due to its non-invasive and convenient characteristics, which attempt to screen and diagnose VAP through analysis of volatile organic compounds (VOCs) in exhalation. Therefore, the research on characterization of VOCs released by VAP pathogens has certain guiding significance for the related breath tests. In this study, the main VAP pathogenic bacteria, including P. aeruginosa, S. aureus, E. coli, E. cloacae, K. pneumoniae, A. baumannii, S. maltophilia, and S. epidermidis, were cultured in tryptic soy broth (TSB) culture medium in vitro, and their headspace samples were obtained after 10 hours of shaking culture. Then, non-targeted detection of VOCs in the headspace was performed by using solid phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC-MS). It was found that a total of 44 differential amounts of VOCs were released by the 8 strains. Subsequently, these bacterial VOCs were classified and discussed according to ketones, aldehydes, ethers, alcohols, acids, esters, alkanes, benzenes, amides, and (nitrogen-containing) heterocycles. These results showed that there was some consistency in the types of VOCs released by the 8 VAP pathogens, such as the production of dimethyl ether and methyl mercaptan. However, there were some differences in the released VOCs among the different pathogens. For example, only S. aureus released 2-butanone and 3-hydroxy-2-butanone, only E. coli produced acetic acid, only E. coli, S. maltophilia, and S. aureus produced N-nenenebc methylformamide. In addition, K. pneumoniae and P. aeruginosa released dimethyl disulfide (DMDS), and S. maltophilia released dimethyl trisulfide (DMTS). This study systematically reports the similarities and differences in the types of VOCs released by VAP pathogens, providing a reference and foundament for VAP related breath research. In the future, it is expected to achieve rapid and non-invasive screening of VAP through exhalation. However, this study did not detect clinically isolated strains or samples, and it was not possible to verify whether there were any differences in results between standard strains and clinical strains. In future work, it is necessary to consider the characteristic spectra of clinically isolated strains and the landmark VOCs in the exhalation of clinical patients. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa is a vector-borne bacterium that causes diseases in many plants of economic interest. The bacterium-vector initial interactions involve bacterial membrane-bound adhesins that mediate cell attachment to the foregut of insect vectors. We investigated the role of the afimbrial adhesin XadA2 in the binding and biofilm formation of X. fastidiosa subsp. pauca to vector surfaces in vitro, as well as its potential to disrupt pathogen transmission. We showed that XadA2 has binding affinity for polysaccharides on sharpshooter hindwings, used as a proxy for the interactions between X. fastidiosa and vectors. When in a medium without carbon sources, the bacterium used wing components, likely chitin, as a source of nutrients and formed a biofilm on the wing surface. There was a significant reduction in X. fastidiosa biofilm formation and cell aggregation on vector wings in competition assays with XadA2 or its specific antibody (anti-XadA2). Finally, pathogen acquisition and transmission to plant were significantly reduced when the vectors acquired X. fastidiosa from an artificial diet supplemented with anti-XadA2. These results show that XadA2 is important in mediating bacterial colonization in the insect and that it could be used as a target for blocking X. fastidiosa transmission.

Xylella fastidiosa is a vector-borne bacterium that causes diseases in many plants of economic interest. The bacterium-vector initial interactions involve bacterial membrane-bound adhesins that mediate cell attachment to the foregut of insect vectors. We investigated the role of the afimbrial adhesin XadA2 in the binding and biofilm formation of X. fastidiosa subsp. pauca to vector surfaces in vitro, as well as its potential to disrupt pathogen transmission. We showed that XadA2 has binding affinity for polysaccharides on sharpshooter hindwings, used as a proxy for the interactions between X. fastidiosa and vectors. When in a medium without carbon sources, the bacterium used wing components, likely chitin, as a source of nutrients and formed a biofilm on the wing surface. There was a significant reduction in X. fastidiosa biofilm formation and cell aggregation on vector wings in competition assays with XadA2 or its specific antibody (anti-XadA2). Finally, pathogen acquisition and transmission to plant were significantly reduced when the vectors acquired X. fastidiosa from an artificial diet supplemented with anti-XadA2. These results show that XadA2 is important in mediating bacterial colonization in the insect and that it could be used as a target for blocking X. fastidiosa transmission.

Background and Aim: Canine monocytic ehrlichiosis is a vector-borne disease caused by the obligatory intracellular bacterium Ehrlichia canis, which is distributed across tropical and subtropical regions worldwide. Its prevalence within dog populations is high in municipalities located across the Pantanal biome, but it remains unknown in Barão de Melgaço, Mato Grosso, Brazil. This study aimed to determine the molecular prevalence and factors associated with E. canis infection in dogs domiciled in Barão de Melgaço. Materials and Methods: A cross-sectional study was carried out to investigate the prevalence of E. canis infection in 369 dogs from urban and rural areas in Barão de Melgaço, North Pantanal wetland, Brazil. Initially, the dogs were examined, and, through a questionnaire, the risk factors were investigated. Blood samples were subjected to DNA extraction and PCR was performed to estimate the prevalence of E. canis infection. Results: The molecular prevalence of E. canis infection in dogs was 42.5% and none of the studied variables were significantly associated with polymerase chain reaction (PCR) positivity (p > 0.05). Conclusion: The high molecular prevalence demonstrates an increased transmission of the agent across the city. This also indicates that attention needs to be paid to E. canis infection and control measures should be introduced to prevent its transmission. The demographic and clinical risk factors commonly associated with E. canis infection in this study were not associated with PCR positivity.

Abstract Background Treponema pallidum (TP) is a spirochaete bacterium with subspecies that in humans cause syphilis (subsp. pallidum), bejel (subsp. endemicum) and yaws (subsp. pertenue; TPE). The latter is target for eradication which requires detailed information on yaws epidemiology. It has been shown that African nonhuman primates (NHPs) are infected with TPE strains that are closely related to the human infecting yaws bacterium. While human yaws infection is known to be endemic in Ghana, there is a paucity of information regarding TPE infection of Ghana's native NHPs. Objectives The objective was to perform a small‐scale cross‐sectional serological screening for antibodies against TPE in Ghanaian monkeys. Due to the reports of TPE‐infected NHPs from neighbouring Côte d'Ivore, we hypothesised that monkeys in Ghana are infected with TPE and, therefore, are seropositive for antibodies against‐Treponema. Methods We sampled blood from 37 NHPs representing four species: Erythrocebus patas (16/37) 43.2%, Papio anubis (15/37) 40.5%, Chlorocebus sabaeus (3/37) 8.1% and Cercopithecus mona (3/37) 8.1%. Samples were tested using the NHP validated treponemal test ESPLINE TP. Results All 37 animals were seronegative for yaws infection. Conclusions We cannot exclude yaws infection in NHPs in Ghana at this point. Our study, in combination with the absence of reports of clinically infected NHPs in a yaws endemic country is, however, supportive for the current thinking that interspecies infection with TPE is extremely rare. This is an important finding for the current ongoing yaws eradication campaign.

Objective: To evaluate the application of microorganisms with native strains on the growth of Morus alba Linn under semi-controlled conditions. Materials and Methods: The work was carried out at the Mountain Development Center, El Salvador municipality, Guantánamo province. Stakes of M. alba, 30 cm long with five buds, were used. Fersialytic soil and organic matter (sheep manure) were used as substrate in a 3:1 ratio. Four concentrations of the microorganism with native strains were applied: 5, 10, 15 and 20 mL/L, which constituted the treatments. A control was used, with water only. A complete randomized experimental design was applied, with 20 plants per treatment. Measurements were branch number, root number, leaf number, branch length, stem diameter and root length. The data were processed from a simple classification analysis of variance. Results: There were no significant differences for the number of branches and number of leaves. Regarding the number of roots, the best treatment was T2, which differed significantly from the others. Treatments T2 and T3 tended to have the highest numerical values. As for branch length and root length, there were significant differences among treatments. No differences were found in stem diameter. The highest numerical values in all indicators were obtained with the application of 5 and 10 mL/L of the bioproduct on M. alba seedlings. Conclusions: With the application of 5 and 10 mL/L of microorganisms with native strains, the performance of branch length, number of roots and root length of M. alba seedlings was favored.

Bioremediation process is one of the most effective methods which facilitates the cleaning of contaminated sites and restores contaminated sites through the broad biodegradative capabilities evolved by microorganisms towards undesirable organic compounds. In this study, Alcaligenes sp. with potential to degrade and utilize used engine oil as its source of carbon and energy was isolated, identified and its growth parameters optimized for efficient and better breakdown of the pollutant. Alcaligenes sp. was isolated from a used engine oil contaminated soil in an old mechanic shop, after enrichment using a carbon free (Bush-Nell Haas) media which was supplemented with used engine oil. The bacterium was identified (morphologically, biochemically, and molecularly) and studied for its ability to extract carbon from used engine oil hence degrading used engine oil. Thereafter, the various growth parameters of the bacterium isolate were optimized. Data obtained showed optimum growth parameter of 2% (v/v) used engine oil (carbon source), pH 7, temperature 37 °C, inoculum size 2 ml and incubation time 240 hours. Also, measured ribosomal RNA (16S RNA) sequence and phylogenetic analysis revealed that the isolate is a very close relative of Alcaligenes species. The degradation potential of the isolate was assessed using gravimetric analysis, and a percentage degradation of 92.5% was discovered. Overall, the results of this study suggest that Alcaligenes sp. can effectively degrade used engine oil, hence, a potential remediation organism against engine oil contamination and spills on soils or water surface.

Abstract The water deficit in particular, reduces the productivity of vegetable crops. To minimize these harmful effects on agriculture, several agronomic and physiological practices are being studied, such as the use of bacteria and water stress attenuators, such as brassinosteroids. Considering the socioeconomic relevance of corn culture and its sensitivity when exposed to water deficit, the objective of the present study was to evaluate the action of brassinosteroids and azospirillum on nitrogen metabolism in corn plants subjected to water stress conditions. The experiment was carried out in a greenhouse, in a period of 47 days, with corn plants, using the hybrid K9606 VIP3. The design was completely randomized, in a 2x2x3 factorial scheme, with six replications. The first factor corresponds to two water regimes (presence and absence of water deficit). The second corresponds to inoculation via seed of Azospirillum brasiliense and absence of inoculation. And the third corresponds to the application of three concentrations of brassinosteroids (0, 0.3 and 0.6 μM). Were determined Nitrate; nitrate reductase; free ammonium; total soluble aminoacids; soluble proteins; proline; glycine betaine and glutamine synthetase. The lack of water in plants provided a reduction in the protein and nitrate reductase contents, in leaves and roots. For ammonium, plants with water deficit inoculated at a concentration of 0.3 μM, obtained an increase of 7.16 (70.26%) and 13.89 (77.04%) mmol NH4 + .Kg-1. DM (Dry mass) on the leaf and root respectively. The water deficit in the soil provided significant increases in the concentrations of glycine betaine, nitrate, proline and aminoacids, both in the leaves and in the roots of the corn plants. On the other hand, the contents of glutamine synthetase had a reduction in both leaves and roots.

Background: The ever-growing awareness of environmental problems has led to the implementing of ecological alternatives in industrial production. Cellulases and hemicellulases are the most widely used enzymes in industry, guaranteeing the efficiency of production, with a reduction in chemicals that pollute the environment. Aim. To select Bacillus spp. strains that produce cellulases, β-mannanases, and xylanases for use in animal feed. Materials and methods: Overall, ten strains were studied in plates with minimum medium supplemented with Beech Xylan, locust vean gum, and carboxymethylcellulose for the production of xylanases, β-mannanases, and endo cellulases, respectively. The plates were incubated at 37 ºC for 24 hours and were coated with 0.5% Congo red solution. The diameter of the hydrolysis area, and that of the colony, were determined to calculate the potency index. Results: All the strains showed the capacity to produce the studied enzymes. As a result, 23.3% of enzymatic activity was considered good. Bacillus subtilis E-44 was the strain with the best enzymatic activity on the three evaluated substrates (3.01 ± 1.18; 3.82 ± 0.31, and 4.22 ± 0.23) for cellulases, β-mannanases, and xylanases, respectively. Conclusions: Bacillus subtilis E-44 was selected as the best cellulase and hemicellulase-producing strain, increasing their possibilities in animal nutrition and the food industry. [ABSTRACT FROM AUTHOR]

Background: Genus Bacillus is among the most widely studied bacteria used as probiotics in aquaculture. Besides its bioflocculant activity, it can offer other benefits, such as nitrogen recycling in the culture pond. Aim. To review the application of Bacillus in shrimp culture, particularly due to its bioflocculant effects on Biofloc systems. Development: Bacillus sp. produces a broad range of extracellular polymeric substances (EPS) and antimicrobial peptides against a variety of microorganisms, in addition to improving the immune response and growth of cultured animals and disease control. The bioflocculant potential of Bacillus species makes these bacteria good candidates for use in Penaeus vannamei cultures in Bioflock systems. Conclusions: However, new bioflocculant Bacillus strains must be isolated and characterized, along with an evaluation of the bioflocculant effect on Penaeus vannamei's metabolism and immune response. [ABSTRACT FROM AUTHOR]

Acidovorax citrulli is the causative agent for bacterial fruit blotch in melons and watermelons. This disease causes several problems in the production and consumption of watermelon. The knowledge of the chemical profile of the interaction between the bacteria and the fruit can help in the adoption of measures to control this disease. Thus, this study investigated the volatile organic compounds (VOCs) in the fruit and seed of infected and healthy watermelon. In the present study, we used headspace-solid phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). Chemometric analysis, Hierarchical cluster analysis (HCA) and Principal component analysis (PCA), was used and the results show that this technique associate to GC–MS can be used to differentiate healthy from infected samples. Phenylethyl alcohol was produced by bacteria cultivated in vitro as well as in infected fruits and healthy and infected seeds. Therefore, detection of some phenolic compounds (phenol, benzyl alcohol, p-cresol and 2-mehoxy-phenol), acetoin and 2,3-butanediol was observed in the infected samples, which indicated the presence of a possible defense mechanism against infection.

Plant flavonoids have attracted increasing attention as new antimicrobial agents or adjuvants. In our previous work, it was confirmed that the cell membrane is the major site of plant flavonoids acting on the Gram-positive bacteria, which likely involves the inhibition of the respiratory chain. Inspired by the similar structural and antioxidant characters of plant flavonoids to hydro-menaquinone (MKH2), we deduced that the quinone pool is probably a key target of plant flavonoids inhibiting Gram-positive bacteria. To verify this, twelve plant flavonoids with six structural subtypes were preliminarily selected, and their minimum inhibitory concentrations (MICs) against Gram-positive bacteria were predicted from the antimicrobial quantitative relationship of plant flavonoids to Gram-positive bacteria. The results showed they have different antimicrobial activities. After their MICs against Staphylococcus aureus were determined using the broth microdilution method, nine compounds with MICs ranging from 2 to 4096 μg/mL or more than 1024 μg/mL were eventually selected, and then their MICs against S. aureus were determined interfered with different concentrations of menaquinone−4 (MK−4) and the MKs extracted from S. aureus. The results showed that the greater the antibacterial activities of plant flavonoids were, the more greatly their antibacterial activities decreased along with the increase in the interfering concentrations of MK−4 (from 2 to 256 μg/mL) and the MK extract (from 4 to 512 μg/mL), while those with the MICs equal to or more than 512 μg/mL decreased a little or remained unchanged. In particular, under the interference of MK−4 (256 μg/mL) and the MK extract (512 μg/mL), the MICs of α-mangostin, a compound with the greatest inhibitory activity to S. aureus out of these twelve plant flavonoids, increased by 16 times and 8 to 16 times, respectively. Based on the above, it was proposed that the quinone pool is a key target of plant flavonoids inhibiting Gram-positive bacteria, and which likely involves multiple mechanisms including some enzyme and non-enzyme inhibitions. [ABSTRACT FROM AUTHOR]

Attempting to couple photochemical CO2 reduction with N2 fixation is usually difficult, because the reaction conditions for these two processes are typically incompatible. Here, we report that a light-driven biohybrid system can utilize abundant, atmospheric N2 to produce electron donors via biological nitrogen fixation, to achieve effective photochemical CO2 reduction. This biohybrid system is constructed by incorporating molecular cobalt-based photocatalysts into N2-fixing bacteria. It is found that N2-fixing bacteria can convert N2 into reductive organic nitrogen and create a localized anaerobic environment, which allows the incorporated photocatalysts to continuously perform photocatalytic CO2 reduction under aerobic conditions. Specifically, the light-driven biohybrid system displays a high formic acid production rate of over 1.41 × 10−14 mol h−1 cell−1 under visible light irradiation, and the organic nitrogen content undergoes an over-3-fold increase within 48 hours. This work offers a useful strategy for coupling CO2 conversion with N2 fixation under mild and environmentally benign conditions. [ABSTRACT FROM AUTHOR]

Abstract Background Forest musk deer is an endangered species globally. The death of captive forest musk deer can be caused by certain respiratory system diseases. Acute respiratory distress syndrome (ARDS) is a huge threat to the life of forest muck deer that breed in our department. Methods Lung histopathologic analysis was conducted by hematoxylin and eosin (HE) staining. The lung gene changes triggered by ARDS were examined by RNA sequencing and related bioinformatics analysis in forest musk deer. The potential functions of unigenes were investigated by NR, SwissProt KOG, GO, and KEGG annotation analyses. Vital biological processes or pathways in ARDS were examined by GO and KEGG enrichment analyses. Results A total of 3265 unigenes were differentially expressed (|log2fold-change|> 2 and adjusted P value

Tomato bacterial canker caused by Clavibacter michiganensis (Cm) is considered to be one of the most destructive bacterial diseases of tomato. To date, no resistance to the pathogen has been identified. While several molecular studies have identified (Cm) bacterial factors involved in disease development, the plant genes and mechanisms associated with susceptibility of tomato to the bacterium remain largely unknown. Here, we show for the first time that tomato gene SlWAT1 is a susceptibility gene to Cm. We inactivated the gene SlWAT1 through RNAi and CRISPR/Cas9 to study changes in tomato susceptibility to Cm. Furthermore, we analysed the role of the gene in the molecular interaction with the pathogen. Our findings demonstrate that SlWAT1 functions as an S gene to genetically diverse Cm strains. Inactivation of SlWAT1 reduced free auxin contents and ethylene synthesis in tomato stems and suppressed the expression of specific bacterial virulence factors. However, CRISPR/Cas9 slwat1 mutants exhibited severe growth defects. The observed reduced susceptibility is possibly a result of downregulation of bacterial virulence factors and reduced auxin contents in transgenic plants. This shows that inactivation of an S gene may affect the expression of bacterial virulence factors. [ABSTRACT FROM AUTHOR]

The risk of zoonosis transmission when handling livestock or animal products is substantial, ‘One Health’ interventions should be an effective strategy for the control of many zoonotic bacteria. In this study, 26 fresh fecal samples from 2 clinically healthy goats were collected at different day ages to survey goat-borne zoonotic bacterial infection, and 19 fresh fecal samples from diarrhetic goats were tested to evaluate the possible role of zoonotic pathogens in goat diarrhea. Following all samples were analyzed by Metagenomic Sequencing, a total of 20 kinds of zoonotic bacteria were screened from healthy goats, and 11 (55%) of them were infection mainly during the preweaned period. Of the 19 fresh fecal samples from diarrhetic goats, all were confirmed to be zoonotic bacterial infection positive (range from 11 to 12 species). After comparison with healthy samples of the same or similar day-age goats, it was found that Lactococcus garvieae, Helicobacter pylori, Klebsiella pneumoniae, Shigella sonnei, Shigella boydii, Campylobacter coli, Salmonella enterica, Acinetobacter baumannii, Shigella flexneri, Shigella dysenteriae and Clostridium perfringens and Campylobacter fetus were highly increased incases in some diarrheic cases, while the remains had no significant change. The results suggest that goats may act as a reservoir for many zoonotic bacteria, and some of them may be associated with goat intestinal inflammation.