Pathogenic Strains Research Articles

The healthy human gut can take it all: vancomycin-variable, linezolid-resistant strains and specific bacteriocin-species interplay in Enterococcus spp.

Enterococcus spp. are opportunistic human pathogens colonizing the human gut and a significant reservoir for the continuous adaptation of hospital clones. However, studies on the features of enterococci species co-colonizing healthy individuals are scarce. We investigated the prevalence, antibiotic resistance, and bacteriocin profiles of Enterococcus species in fecal samples from healthy adults in Portugal using culture-based methods, WGS, and bacteriocin inhibition assays. Results were compared with data from a 2001 study in the same region. Enterococcus spp. (n = 315; 24% MDR) were recovered from all volunteers. Enterococcus lactis was the prevalent species (75%), followed by Enterococcus faecalis (65%) and Enterococcus faecium (47%). E. lactis prevalence increased 2.5-fold since 2001. Linezolid resistance genes (optrA/poxtA) were detected in E. faecium and Enterococcus thailandicus isolates, while a vancomycin-variable E. faecium was also identified. Virulence and plasmid profiles were diverse across species, with evidence of exchange of virulence markers and plasmid replicons between E. faecium and E. lactis. Bacteriocin gene repertoires were extensive and species-specific. Higher numbers of bacteriocin genes were associated with stronger inhibition profiles, and 25% of E. faecium and E. lactis isolates were capable of inhibiting relevant VRE clones. This study unveils the co-occurrence and ecological dynamics of Enterococcus species in the healthy human gut, reinforcing its role as a reservoir for key antibiotic resistance genes and potentially pathogenic strains. The shift toward E. lactis prevalence and the detection of linezolid resistance genes in healthy individuals underscore the need for ongoing surveillance of the gut microbiome to guide public health strategies and antibiotic stewardship efforts.IMPORTANCEThis study highlights the role of Enterococcus species in the healthy human gut, revealing important insights into their prevalence and antibiotic resistance. It emphasizes that the human gut serves as a significant reservoir for antibiotic-resistant strains and shows a notable increase and prevalence of Enterococcus lactis, which has been underappreciated due to identification challenges. The research also underscores the bacteriocins' role in microbial competition, where commensal strains inhibit clinical VRE, potentially aiding the restoration of the gut microbiota, after antibiotic treatment. The findings accentuate the need for ongoing surveillance to track changes in gut bacteria, especially with the emergence of resistance genes to last resort antibiotics. Such monitoring is crucial for shaping public health strategies and managing the growing threat of antibiotic-resistant infections. Profiling bacteriocins at the species and strain level can identify ecological adaptation factors and inform strategies to target high-risk clones.

In Vitro Evaluation of Probiotic Activities and Anti-Obesity Effects of Enterococcus faecalis EF-1 in Mice Fed a High-Fat Diet

This research sought to assess the anti-obesity potential of Enterococcus faecalis EF-1. An extensive and robust in vitro methodology confirmed EF-1’s significant potential in combating obesity, probably due to its excellent gastrointestinal tract adaptability, cholesterol-lowering property, bile salt hydrolase activity, α-glucosidase inhibition, and fatty acid absorption ability. Moreover, EF-1 exhibited antimicrobial activity against several pathogenic strains, lacked hemolytic activity, and was sensitive to all antibiotics tested. To further investigate EF-1’s anti-obesity properties in vivo, a high-fat diet (HFD) was used to induce obesity in C57BL/6J mice. Treatment with EF-1 (2 × 109 CFU/day) mitigated HFD-induced body weight gain, reduced adipose tissue weight, and preserved liver function. EF-1 also ameliorated obesity-associated microbiota imbalances, such as decreasing the Firmicutes/Bacteroidetes ratio and boosting the levels of bacteria (Faecalibacterium, Mucispirillum, Desulfovibrio, Bacteroides, and Lachnospiraceae_NK4A136_group), which are responsible for the generation of short-chain fatty acids (SCFAs). Concurrently, the levels of total SCFAs were elevated. Thus, following comprehensive safety and efficacy assessments in vitro and in vivo, our results demonstrate that E. faecalis EF-1 inhibits HFD-induced obesity through the regulation of gut microbiota and enhancing SCFA production. This strain appears to be a highly promising candidate for anti-obesity therapeutics or functional foods.

Whole-Genome Sequencing and Genome Annotation of Pathogenic Elsinoë batatas Causing Stem and Foliage Scab Disease in Sweet Potato

A pathogen strain responsible for sweet potato stem and foliage scab disease was isolated from sweet potato stems. Through a phylogenetic analysis based on the rDNA internal transcribed spacer (ITS) region, combined with morphological methods, the isolated strain was identified as Elsinoë batatas. To comprehensively analyze the pathogenicity of the isolated strain from a genetic perspective, the whole-genome sequencing of E. batatas HD-1 was performed using both the PacBio and Illumina platforms. The genome of E. batatas HD-1 is about 26.31 Mb long in 167 scaffolds, with a GC content of 50.81%, and 7898 protein-coding genes, 131 non-coding RNAs, and 1954 interspersed repetitive sequences were predicted. Functional annotation revealed that 408 genes encode virulence factors involved in plant disease (DFVF—Plant). Notably, twenty-eight of these virulence genes encode secretory carbohydrate-active enzymes (CAZymes), including two endo-1,4-β-xylanase genes and seven cutinase genes, which suggested that endo-1,4-β-xylanase and cutinase play a vital role in the pathogenicity of E. batatas HD-1 within sweet potato. In total, twelve effectors were identified, including five LysM effectors and two CDIP effectors, suggesting that LysM and CDIP effectors play significant roles in the interaction between E. batatas HD-1 and sweet potato. Additionally, our analysis of biosynthetic gene clusters (BGCs) showed that two gene clusters are involved in melanin and choline metabolism. This study enriches the genomic resources of E. batatas and provides a theoretical foundation for future investigations into the pathogenic mechanisms of its infection in sweet potatoes, as well as potential targets for disease control.

Emerging Aeromonas spp. infections in Europe: characterization of human clinical isolates from German patients

Bacteria of the genus Aeromonas are widely distributed in water bodies around the world. Some Aeromonas species have been identified as human pathogens causing intestinal and a variety of extraintestinal infections. In Germany, information on diseases caused by Aeromonas is rare, because Aeromonas infections are not notifiable in Germany. To address this information gap and gain better insights, a successful collaboration with human medical diagnostic laboratories within Germany was established and several Aeromonas isolates from diseased patients were sent to the Aeromonas laboratory of the German Federal Institute for Risk Assessment. 52 clinical Aeromonas isolates, of which anonymized patients’ data were available, were selected for further characterization by MALDI-TOF MS, biochemical testing, and whole genome sequencing (WGS). Nearly half of the isolates were from patients older than 60 years, whereas only four isolates were from patients aged up to 10 years. 30 isolates originated from stools of patients with diarrhea/(gastro-)enteritis and 22 strains were from patients with diverse extraintestinal infections, such as wound infection, septicemia, bursitis, abscesses, cholangitis, urinary tract infections, and pneumonia. Taxonomical identification revealed following predominant species: A. veronii biovar sobria (18 isolates), A. caviae (17 isolates), and A. hydrophila (nine isolates). Two A. salmonicida isolates and one isolate each of A. dhakensis, A. bestiarum, and A. encheleia were also identified. Three closely related intestinal isolates could not be assigned to a recognized Aeromonas species. The clustering of strains based on virulence factor profile resulted in a grouping that closely resembles the clustering of the phylogenetic tree suggesting that the profiles are specific for each species. Our study on clinical Aeromonas isolates characterizes for the first time human pathogenic strains isolated in Germany. These bacteria are important microorganisms within the One Health context because of their ubiquitous presence in the environment and as a cause of opportunistic infections in humans and animals. Infections caused by Aeromonas bacteria show a seasonality with increased infection rates in warmer periods. In view of climate change, Aeromonas bacteria are regarded as emerging pathogens and research is required to determine the reservoirs in One Health sources from which human infections may arise.

Molecular Detection of a Novel Poxvirus in Black Bullhead (Ameiurus melas): Emerging Pathogens in a Natural Freshwater in Hungary?

Unexpected mass mortality of black bullhead Ameiurus melas (Rafinesque, 1820) fingerlings occurred 1 week after their arrival at our animal facility. The specimens of the invasive fish species originated from Lake Balaton, the largest natural freshwater lake in Hungary. The mortality reached 100% within 3 days. Gross pathological examination detected inflammation in the inner organs, renomegaly, and a marble, pale pink liver. Two pathogenic bacteria strains, Vibrio cholerae Pacini, 1854, and Plesiomonas shigelloides (Bader 1954), were detected in the fish liver examined. The molecular virological examination showed the presence of the nucleic acid of two dsDNA viruses. One is the Ictalurid herpesvirus 2 (IcHV-2), which is a well-known pathogen of the black bullhead that has only been reported from Italian fish farms previously. This is the first report of IcHV-2 from a natural freshwater habitat. The other viral DNA detected in fish belongs to an unidentified virus species. Sequence analysis of the partial DNA polymerase gene confirmed that the novel virus is a member of the subfamily Chordopoxvirinae within the family Poxviridae. Although the causative agent of this mass mortality could not be identified with certainty, the clinical signs suggest that the detected viruses are the most suspicious. Furthermore, our results highlight that the health monitoring of invasive species is also important for the timely detection of pathogens that threaten the native fish fauna.

Analysis of the genetic features of the structural organization of integrative conjugative (ICE) elements of Vibrio cholerae strains of various origins

BACKGROUND: Integrative conjugative elements (ICE) make a significant contribution to the spread of bacterial antibiotic resistance genes among cholera pathogen strains. However, at the moment there are no unified methods for typing ICE elements that allow analyzing a large number of genomes. AIM: The aim of the study was to conduct a comparative analysis of the genetic organization and identify features in the structure of integrative conjugative (ICE) elements with the development of new methods for automating their rapid typing in genome-wide sequencing data, followed by the study of a representative collection of genomes of V. cholerae strains of various origins. METHODS: The work uses data from genome-wide sequencing (WGS) of toxigenic (ctxAB+tcpA+) 120 strains of V. cholerae O1 El Tor obtained on the MiSeq platform (Illumina, USA) and MinIon (Oxford Nanopore, UK), and from the NCBI databases (1887 strains) and the European Nucleotide Archive (441 strains). The software for detecting and typing the ICE element is developed in the Java programming language, version 11.0.13 and is located at http://antiplague.ru/ice-genotyper/. RESULTS: A comparative analysis of ICE elements in toxigenic strains of cholera vibrions was carried out. An algorithm for typing ICE elements based on their genetic composition is proposed. Analysis of the genome collection of V. cholerae strains revealed three previously undescribed ICE elements, designated as ICEVchRus1, ICEVchHai3 and ICEVchLaos. Discussion. The distribution of various types of ICE elements in Russia and the world has been studied. It is shown that some variants of ICE elements, despite their almost identical composition, have different designations in the world literature.

Metagenomic Analysis of Gut Microbiome of Persistent Pulmonary Hypertension of the Newborn.

Persistent pulmonary hypertension of the newborn (PPHN) is one of the most common diseases in the neonatal intensive care unit which severely affects neonatal survival. Gut microbes play an increasingly important role in human health, but there are rarely reported how gut microbiota contribute to PPHN. In our study, the metagenomic sequencing of feces from 12 PPHN's neonates and 8 controls were performed to expose the relation between neonatal gut microbes and PPHN disease. Firstly, we found that the abundance of Actinobacteria, Proteobacteria, Bacteroidetes were significantly increased in PPHN compared with controls, but the Firmicutes components was reduced. And some pathogenic strains (like Vibrio metschnikovii) were significantly enriched in the PPHN compared with controls. Secondly, functional annotation of genes found that PPHN up-regulated transmembrane transport, but down-regulated ribosome and ATP binding. Lastly, microbial metabolic pathway enrichment analysis indicated that some metabolic pathway in PPHN were conflicting and contradictory, showed that an abnormally increased metabolism, disturbed protein synthesis and genomic instability in the PPHN neonate. Our results contribute to understanding the changes in the species and function of gut microbiota in PPHN, thus providing a theoretical basis for the explanation and treatment of PPHN.

From Structure to Function: How Prebiotic Diversity Shapes Gut Integrity and Immune Balance

The microbiota stability, diversity, and composition are pillars for an efficient and beneficial symbiotic relationship between its host and itself. Microbial dysbiosis, a condition where a homeostatic bacterial community is disturbed by acute or chronic events, is a predisposition for many diseases, including local and systemic inflammation that leads to metabolic syndrome, diabetes, and some types of cancers. Classical dysbiosis occurs in the large intestine. During this period, pathogenic strains can multiply, taking advantage of the compromised environment. This overgrowth triggers an exaggerated inflammatory response from the human immune system due to the weakened integrity of the intestinal barrier. Such inflammation can also directly influence higher polyp formation and/or tumorigenesis. Prebiotics can be instrumental in preventing or correcting dysbiosis. Prebiotics are molecules capable of serving as substrates for fermentation processes by gut microorganisms. This can promote returning the intestinal environment to homeostasis. Effective prebiotics are generally specific oligo- and polysaccharides, such as FOS or inulin. However, the direct effects of prebiotics on intestinal epithelial and immune cells must also be taken into consideration. This interaction happens with diverse prebiotic nondigestible carbohydrates, and they can inhibit or decrease the inflammatory response. The present work aims to elucidate and describe the different types of prebiotics, their influence, and their functionalities for health, primarily focusing on their ability to reduce and control inflammation in the intestinal epithelial barrier, gut, and systemic environments.

Unveiling the Potency: Synthesis and Assessment of Antimicrobial Potential of Some Bis(indolyl)methane Derivatives

Background: The urgent need for new antimicrobial compounds arises from the growing threat of multidrug-resistant human pathogens responsible for infectious diseases. The indole moiety, a prevalent heterocyclic ring system found in nature, is a key structural element in many pharmaceutical agents due to its wide range of biological activities. Bis(in-dolyl)methanes, in particular, have emerged as promising candidates for antibacterial activ-ity. Aim: This study aimed to evaluate the antibacterial activity of nine bis(indolyl)methane derivatives against a range of pathogenic bacterial strains responsible for various human diseases. Methods: The compounds were synthesized using a solvent-free method, and their antibac-terial activity was evaluated using the disk diffusion assay. The minimum inhibitory con-centration (MIC) of the active compounds identified in the disk diffusion assay was deter-mined by the microtiter broth dilution method in 96-well microtiter plates. Bacterial strains in the mid-log phase of growth were utilized. Bacterial suspensions equivalent to 0.5 McFar-land standards were prepared by suspending the bacterial inoculum in sterile water. A work-ing concentration of 100 μg/mL was achieved by diluting the test compounds in 100% DMSO. Results: The antimicrobial activity of nine synthetic compounds was evaluated against nine medically significant pathogenic strains. These include Pseudomonas aeruginosa, Bacillus cereus, and Shigella flexneri, known for producing toxins that cause acute foodborne ill-nesses, as well as Escherichia coli K12 and Enterococcus faecalis, which can disrupt the intestinal barrier in immunocompromised individuals. The results suggest that these com-pounds have the potential to be effective antimicrobial agents. Conclusion: Our findings demonstrate the promising antimicrobial activity of the synthe-sized compounds, with 1-ethyl-3-((1-ethyl-1H-indol-3-yl)(phenyl)methyl)-1H-indole emerging as the most potent, significantly inhibiting most tested bacterial strains. These results highlight the potential for developing novel compounds for antibacterial treatment.

Biosynthesis, Characterization, and Antibacterial Activity of Gold, Silver, and Bimetallic Nanoparticles Using Annona squamosa L. Leaves

The utilization of nano-sized drug delivery systems in herbal drug delivery systems has a promising future for improving drug effectiveness and overcoming issues connected with herbal medicine. As a consequence, the use of nanocarriers as novel drug delivery systems for the improvement of traditional medicine is critical to combating infectious diseases globally. In line with this, we herein report the biosynthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), and bimetallic nanoparticles (BMNPs) as antibacterial agents against pathogenic bacterial strains using Annona squamosa L. leaf extract as a bio-reductant and bio-stabilizing agent. The as-synthesized metal nanoparticles were characterized by transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis) absorption spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and the dynamic light scattering (DLS) method. The as-synthesized MNPs had an average particle size of 6.98 nm ± 2.86 nm (AgNPs), 21.84 ± 8.72 nm (AuNPs), and 2.05 nm ± 0.76 nm (BMNPs). The as-synthesized AgNPs and BMNPs showed good antibacterial activity against pathogenic bacterial strains of Gram-positive Staphylococcus aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922). The obtained results offer insight into the development of benign nanoparticles as safe antibacterial agents for antibiotic therapy using Annona squamosa L. leaf extract.

Genomic analysis, culturing optimization, and characterization of Escherichia bacteriophage OSYSP, previously studied as effective pathogen control on fresh produce

Advances in bacteriophage genome sequencing and regulatory approvals of some bacteriophages in various applications have renewed interest in these antibacterial viruses as a potential solution to persistent food safety challenges. Here, we analyzed in depth the genome of the previously studied Escherichia bacteriophage OSYSP (phage OSYSP), revealed its application-related characteristics, and optimized its enumeration techniques for facilitating industrial implementation. We previously sequenced phage OSYSP genome completely by combining results from Illumina Miseq and Ion Torrent sequencing platforms and completing the remaining sequence gaps using PCR. Based on the genomics analysis completed herein, phage OSYSP was confirmed as an obligate lytic phage of the Caudoviricetes class. The genome encodes 81 proteins of identifiable functions, including two endolysins and 45 proteins that support host-independent DNA replication, transcription, and repair. Despite its similarities to T5-like phages, unique genome arrangements confirm phage OSYSP’s novelty. The genomic analysis also confirmed the absence of DNA sequences encoding virulence or antibiotic resistance factors. For optimizing phage detection and quantification in the conventional plaque assay, it was observed that decreasing the concentration of agar or agarose, when used as a medium gelling agent, increased phage recovery (p < 0.05), but using agarose resulted in smaller plaque diameters (p < 0.05). Phage OSYSP inactivated pathogenic and non-pathogenic strains of E. coli and some Salmonella enterica serovars, with more pronounced effect against E. coli O157:H7. Phage titers remained fairly unchanged throughout a 24-month storage at 4°C. Incubation for 30 min at 4°C−47°C or pH 4–11 had no significant detrimental effect (p > 0.05) on phage infectivity. In vitro application of phage OSYSP against E. coli O157:H7 EDL933 decreased the pathogen’s viable population by >5.7-log CFU/mL within 80 min, at a multiplicity of infection as low as 0.01. The favorable genome characteristics, combined with improved enumeration methodology, and the proven infectivity stability, make phage OSYSP a promising biocontrol agent against pathogenic E. coli for food or therapeutic applications.

Nutritional and Bioactive Compounds, Antioxidant Properties and Antibacterial Activity of Chinese Chive (Allium odorum L.).

The present study was conducted to generate the comprehensive data on the nutritional composition, minerals, heavy metal, bioactive compounds, antioxidant and antibacterial properties of Chinese chive (Allium odorum L.) grown at two different locations including Manipur and Punjab. The crop grown in Manipur exhibited higher values of nutritional and phytochemical compound values than those grown in Punjab. It exhibited significantly higher amounts of crude protein, crude fiber, potassium, calcium and iron content in the Manipur environment. The allicin content in leaves of Chinese chive on a dry weight (dw) varied from 1.31 to 1.4% and there was non-significant difference in allicin content at both locations. Besides, the heavy metal content of Chinese chive was much below the permissible limits of the World Health Organization. The IC50 value of Chinese chive was 78.908-95.140µg/ml which imparts strong antioxidant activity and higher DPPH (2,2-diphenyl-1-picrylhydrazyl)radical scavenging activity higher in fresh leaves than dried leaves. Total phenol and total flavonoid were found to be significantly high. In addition, high antibacterial activities were observed against toxin producing pathogenic bacterial strains of Staphylococcus aureus and Enterococcus faecalis. The nutritional and bioactive compounds, antioxidant properties and antibacterial activity of Chinese chive make it ideal for its use as a functional food and/or supplement.

Evaluating the biocontrol efficacy of beneficial soil microbes against the Fusarium wilt disease of tomato

Tomato is one of the most important agricultural crops in the world as it is a rich source of vitamins A and C. The quality and the quantity of tomato fruits is severely affected by the fungal plant pathogens. Fungal diseases are among the most dangerous biological stresses that cause severe damage to tomato crops in many countries. Fusarium wilt disease in tomato caused by Fusarium oxysporum f. sp. lycopersici, become a major concern of yield loss worldwide. This study evaluated the efficacy of multiple antagonistic biocontrol agents, including Trichoderma species and non-pathogenic F. oxysporum, in mitigating Fusarium wilt. Pathogenic F. oxysporum strains were isolated from diseased tomato plants, while biocontrol agents were cultured from rhizosphere soil of healthy tomato plants. In vitro dual-culture assays demonstrated that non-pathogenic F. oxysporum inhibited pathogenic strains by 86.8% (±4.8) at 7 days post-inoculation (dpi), significantly higher than T. harzianum, which achieved 62.8% (±6.2) inhibition (p < 0.01). Other Trichoderma strains, such as T. viride and T. asperellum, showed moderate inhibition levels of 54.3% (±2.3) and 51.9% (±5.9), respectively. Greenhouse pot trials reinforced these in vitro results, with non-pathogenic F. oxysporum achieving a significant disease reduction of 77.0% (±3.0) in Fusarium wilt incidence, followed by T. harzianum at 64.8% (±2.7) (p < 0.01). Statistically significant improvements in plant growth were also recorded in treated plants. T. harzianum increased shoot length by 25.6% (±3.1) and root weight by 22.4% (±2.9) compared to control plants, while non-pathogenic Fusarium enhanced root length by 30.2% (±3.4) and overall biomass by 28.7% (±3.8) (p < 0.01). Data were analyzed using ANOVA, followed by LSD for pairwise comparisons, confirming the efficacy of these biocontrol agents in reducing disease incidence and promoting plant growth. These findings underscore the potential of antagonistic biocontrol agents as viable, sustainable alternatives to chemical fungicides for managing Fusarium wilt in tomato production systems, supporting both plant health and environmental resilience.

Construction and infection characteristics of a GFP‐labelled Botryosphaeria dothidea causing kiwifruit soft rot disease

AbstractSoft rot disease caused by Botryosphaeria dothidea is one of the most important fungal diseases affecting kiwifruit production. The symptoms of the disease generally appear during the fruit storage period, resulting in difficult disease management and serious economic losses. Therefore, the characterization of the infection mechanism needs to be explored to deepen our understanding of the pathogen and the disease. In this study, a highly pathogenic strain JY‐1, causing kiwifruit soft rot, was isolated and identified as B. dothidea. A polyethylene glycol‐mediated genetic transformation system for B. dothidea JY‐1 was established, enabling the successful acquisition of a green fluorescent protein (GFP)‐labelled strain with stable inheritance. The GFP‐labelled transformant Bd13 was generated and used in the research, and the infection process of kiwifruit tissues was studied through wound inoculation essays and fluorescence labelling microscopy. The results of the present study indicate that the transformant Bd13 not only damaged the kiwifruit fruits but also effectively infected and colonized the leaves and shoots of kiwifruit plants, causing shoot blight and leaf spot. These findings contribute to a deeper understanding of the pathogenic mechanisms underlying kiwifruit soft rot and lay a foundation for further investigations into the interaction between the soft rot pathogen B. dothidea and kiwifruit.

In vitro Antifungal Effects of Various Essential Oils against Aspergillus Crown Rot of Peanut

Synthetic fungicides that combat plant pathogenic fungi can enhance crop yields, ensuring stable crop production and market quality. However, the increase in the use of fungicides may cause to development of fungicide-resistant pathogen strains and the accumulation of fungicide residues in the food chain above safe limits. This situation underscores the need for improved fungal disease management through alternatives to synthetic fungicides. These alternatives include plant-derived compounds such as essential oils and extracts. Essential oils are known to be potent antifungal compounds against both human and plant pathogens. Aspergillus niger is a toxin-producing fungal disease agent that causes Aspergillus crown rot in peanuts. In this study, the antifungal activities of nine different essential oils from Foeniculum vulgare, Lippia citriodora, Origanum majorana, Origanum minutiflorum, Origanum onites, Origanum syriacum, Origanum vulgare, Salvia aramiensis and Thymus syriacus plants were evaluated against A. niger under in vitro conditions by using disc diffusion test. Among the nine essential oils tested, the highest antifungal activities were displayed by O. vulgare essential oil (with an inhibition zone diameter of 49.33 mm) which was followed by T. syriacus, O. onites, O. syriacum and O. minutiflorum essential oils (48.67, 47.00, 46.33 and 43.33 mm, respectively). The essential oils of F. vulgare, L. citriodora, and O. majorana showed relatively lower antifungal effects. The essential oil of S. aramiensis did not show antifungal effect against pathogen. The results indicated that plant essential oils could be valuable in promoting research aimed at developing new antifungal agent(s) for fungal disease management. However, further studies are needed to optimize the in vivo application conditions of essential oils against A. niger.

Thwarting the Blight: A Comprehensive Review of Traditional and Molecular Germplasm Screening Techniques for Black Spot Resistance in Roses

Diplocarpon rosae causing rose black spot disease, is one of the most devastating pathogens, that affect the quality of roses, and is responsible for huge yield losses, worldwide. Many approaches have been applied to control this disease including developing resistance variety. However, this review widely evaluates different screening germplasm methods to control the black-spot disease in rose. Additionally, in this review, many major issues influencing the black-spot disease resistance, including environmental factors, plant-pathogen interaction and genetic diversity, providing a complete thoughtful of the multifaceted nature of this disease. Moreover, the variety of screening technique ranging from conventional field assessment to contemporary molecular approaches, emphasizing their respective benefits and restrictions. But, the finding and employing new resistance genes is very difficult due to highly genetic diversity of this pathogen, especially, when their interaction of this pathogen to plant are not completely understood. Because, various isolates and strains of pathogen can relate in diverse ways with different germplasm, making it challenging to identify uniform resistance among all strains. Furthermore, many environmental factors including light, temperature and humidity support to increase the disease development, leading reduce the resistance and tolerance of plant against pathogen. Whereas, developing resistance germplasm might be helpful to control this disease and reduce pathogen infection in plants. In this regard, many plant-omics studies such as transcriptome, genome re-sequencing and proteomics have been widely studied to find out candidate resistance (R) protein and genes, which related to the black-spot disease. This review seeks to provide researchers as well as growers and breeders with a through recourse that combine recent information on the assessment of rose germplasm against black spot disease resistance. By employing newly approaches, we aimed to accelerate the growth of rose varieties, that are beautifully attractive and strong in the appearance on this determined blight. In the last, our collective finding to addresses the issues could be increase the sustainability and visual attractiveness of rose cultivation for future generations.

Antimicrobial Susceptibility Profiles of Commensal Enterococcus spp. Isolates from Chickens in Hungarian Poultry Farms Between 2022 and 2023

Background: The global spread of antimicrobial resistance (AMR) represents one of the most significant challenges of our generation. It is crucial to continuously monitor AMR, not only by investigating clinical, pathogenic strains but also by monitoring commensal bacterial strains, as they can serve as natural reservoirs of resistance. Infections caused by Enterococcus species are increasingly recognized as emerging threats to both animal and public health. Among economically important livestock, poultry as a major source of animal protein for humans is a frequent carrier of enterococci, and also of sporadically detected clinical disease. Methods: This study aimed to determine the antimicrobial susceptibility profile of Enterococcus strains (n = 499) isolated from chicken farms in Hungary. The minimum inhibitory concentration (MIC) was determined for 15 antibiotics, including 10 with established clinical breakpoints. Results: The strains exhibited good sensitivity to amoxicillin, one of the first-line treatments for Enterococcus infections in veterinary medicine, with only 20.8% showing resistance. However, we observed an alarming 27.9% resistance rate to vancomycin, which is reserved to treat infections caused by multidrug-resistant strains in humans. A comparison of our findings with Hungarian hospital records revealed that the resistance patterns of poultry-derived Enterococcus faecalis strains were very similar to those of human isolates, particularly regarding penicillins and aminoglycosides. Conclusions: Overall, the increasing rates of AMR reinforce the importance of conducting periodic studies to establish long-term trends. For multidrug-resistant strains, next-generation sequencing is recommended to elucidate the genetic basis of resistance.

Susceptibility pattern of Ceftazidime-Avibactam against multi drug resistant gram-negative rods

This study was conducted to evaluate the susceptibility pattern of ceftazidime avibactam against multi drug resistant gram negative rods. This prospective study cross sectional study conducted in Microbiology Section of Dow Diagnostic Reference and Research Laboratory, Dow University of Health Sciences, Karachi, Pakistan. Identification of isolates was done in accordance with the standard bacteriological technique, and were distinguished based on gram staining, colony morphology and biochemical tests. Antibiotic susceptibility testing (AST) was performed on Muller-Hinton agar by Kirby-Bauer Disk Diffusion method in accordance with the Clinical Laboratory Standard Institute (CLSI) guidelines. Good sensitivity of Lactose fermenters (Escherichia coli, Klebsiella pneumoniae and Enterobacter) were observed against Ceftazidime avibactam. Pseudomonas aeruginosa exhibited 42% resistance in all clinical samples. Proteus species and Serratia have shown high resistance in our study. Our observations showed the persistence of high ceftazidime avibactam activity against pathogenic and multi drug resistant strains of Enterobacterales and Non lactose fermenting bacteria.

Avian influenza: A new threat to wild bird conservation?

<p>Avian influenza, also known as bird flu, significantly threatens wild bird populations and global biodiversity. As wild birds are natural reservoirs for various strains of the influenza virus, they have a crucial role in the epidemiology of the disease, which has profound implications for both wildlife conservation and public health. The emergence and dispersion of highly pathogenic avian influenza strains, particularly H5N1, have resulted in large-scale mortality events in wild bird populations, disrupting ecosystems and threatening endangered species. The conservation of wild birds in the context of avian flu involves several critical actions, including surveillance, rapid response to outbreaks, habitat management, and minimizing human-wildlife interactions that facilitate virus transmission. Studying avian influenza’s impact on wild bird populations is crucial due to its dual importance in wildlife conservation and public health. Wild birds, as natural reservoirs of the virus, play a central role in its spread, with highly pathogenic strains like H5N1 causing devastating mortality events that disrupt ecosystems and endanger species. Effective management, including monitoring, rapid outbreak response, and habitat protection, is essential to mitigate these effects. Collaboration among experts is vital to protect biodiversity, sustain ecological balance, and reduce risks to human health, ensuring the long-term survival of wild bird populations.<strong></strong></p>

Ciprofloxacin-induced mucoviscosity in ESBL-positive Escherichia coli carrying the Klebsiella pneumoniae K23 capsular structure hinders phagocytosis.

Escherichia coli is a Gram-negative ubiquitous bacteria occurring in a diversity of environments including water, soil, and the gastrointestinal tract of humans and warm-blooded animals, being classified into commensal and pathogenic strains. While empirical antibiotic therapy with fluoroquinolones, such a ciprofloxacin and norfloxacin, has been a common practice, resistance to broad-spectrum cephalosporins, mediated by extended-spectrum β-lactamases (ESBLs), has been alerted as a critical priority by the World Health Organization. Additionally, the convergence of virulence and resistance has been observed in some E. coli strains, which enable these bacteria to infect humans and animals, and can jeopardize their health. Mucoviscosity phenotype has been frequently described in highly-virulent Klebsiella pneumoniae strains, whereas this phenotypic behavior remains rarely reported in E. coli. Herein, we report microbiological, genomic, and anti-phagocytic activity of ciprofloxacin-induced mucoviscosity in a CTX-M-15 (ESBL)-positive E. coli. Noteworthy, genomic analysis revealed virulence genes responsible for the synthesis of the K23 capsule type, previously described in hypermucoviscous K. pneumoniae lineages, whereas phagocytosis assays confirmed the ability of K23 E. coli strain to evade the immune system under mucoviscosity induction by ciprofloxacin treatment.