Search Results (379)

The aim of this study was to isolate and identify lactic acid bacteria (LAB) from a traditional fermented beverage, Boza, and to conduct an in-depth study on their fermentation and probiotic properties. The fermentation (acid production rate, acid tolerance, salt tolerance, amino acid decarboxylase activity) and probiotic properties (gastrointestinal tolerance, bile salt tolerance, hydrophobicity, self-aggregation, drug resistance, bacteriostatic properties) of the 16 isolated LAB were systematically analyzed by morphological, physiological, and biochemical tests and 16S rDNA molecular biology. This analysis utilized principal component analysis (PCA) to comprehensively evaluate the biological properties of the strains. The identified LAB included Limosilactobacillus fermentum (9 strains), Levilactobacillus brevis (2 strains), Lacticaseibacillus paracasei (2 strains), and Lactobacillus helveticus (3 strains). These strains showed strong environmental adaptation at different pH (3.5) and temperature (45 °C), with different gastrointestinal colonization, tolerance, and antioxidant properties. All the strains did not show hemolytic activity and were inhibitory to Staphylococcus aureus, and showed resistance to kanamycin, gentamicin, vancomycin, and streptomycin. Based on the integrated scoring of biological properties by principal component analysis, Limosilactobacillus fermentum S4 and S6 and Levilactobacillus brevis S5 had excellent fermentation properties and tolerance and could be used as potential functional microbial resources. Full article

Vibrio parahaemolyticus is the leading bacterial cause of gastroenteritis associated with aquatic food consumption globally. This study aimed to determine the prevalence of V. parahaemolyticus in aquatic foods from Huzhou and to identify the serotypes, antimicrobial resistance, virulence factors, and genetic relatedness of the strains. A total of 306 isolates were detected from 1314 aquatic food samples from 2022 to 2024. The results indicated that the most prevalent serotypes were O1:KUT (17.0%), O2:K28 (13.7%), and O2:KUT (13.1%). Multilocus sequence typing analysis divided the 306 isolates into 175 sequence types (STs), and the predominant sequence type was ST864 (3.3%). Antimicrobial susceptibility tests showed that 2.6% of isolates were multidrug resistant. High resistance was observed to ampicillin (64.7%) and streptomycin (44.4%). A total of seven antimicrobial categories of resistance genes were identified, and the resistance gene bla_CARB was detected in all isolates. The virulence genes tdh and trh were found in 16 (5.2%) and 12 (3.9%) isolates, respectively. In addition, we observed that all the 306 V. parahaemolyticus isolates encode type III secretion systems 1. The phylogenomic analysis based on the whole-genome sequence revealed that the 306 isolates were divided into four clusters. Our findings broaden perspectives on V. parahaemolyticus genetic diversity and enhance our ability to assess the potential risks of its spread. Full article

Cancer remains one of the leading causes of death globally, highlighting the urgent need for novel anticancer therapies with higher efficacy and reduced toxicity. Similarly, the rise in multidrug-resistant pathogens and emerging infectious diseases underscores the critical demand for new antimicrobial agents that target resistant infections through unique mechanisms. This study used computational approaches to investigate twenty quinolone–triazole and conazole–triazole hybrid derivatives as antimicrobial and anticancer agents (1–20) with nine reference drugs. By studying their interactions with 6 bacterial DNA gyrase and 10 cancer-inducing target proteins (E. faecalis, M. tuberculosis, S. aureus, E. coli, M. smegmatis, P. aeruginosa and EGFR, MPO, VEGFR, CDK6, MMP1, Bcl-2, LSD1, HDAC6, Aromatase, ALOX15) and comparing them with established drugs such as ampicillin, cefatrizine, fluconazole, gemcitabine, itraconazole, ribavirin, rufinamide, streptomycin, and tazobactam, compounds 15 and 16 emerged as noteworthy antimicrobial and anticancer agents, respectively. In molecular dynamics simulations, compounds 15 and 16 had the strongest binding at −10.6 kcal mol⁻¹ and −12.0 kcal mol⁻¹ with the crucial 5CDQ and 2Z3Y proteins, respectively, exceeded drug-likeness criteria, and displayed extraordinary stability within the enzyme’s pocket over varied temperatures (300–320 K). In addition, we used density functional theory (DFT) to calculate dipole moments and molecular orbital characteristics and analyze the thermodynamic stability of putative antimicrobial and anticancer derivatives. This finding reveals a well-defined, possibly therapeutic relationship, supported by theoretical and future in vitro and in vivo studies. Compounds 15 and 16, thus, emerged as intriguing contenders in the fight against infectious diseases and cancer. Full article

Brucellosis remains endemic in Tunisia, causing abortions in small ruminants, and represents a public health threat through occupational exposure and the consumption of contaminated animal products. The aims of this study are to assess the antibiotic susceptibility of two Brucella melitensis isolates (TATA and SBZ) from aborted sheep, to analyze their genomes using hybrid whole-genome sequencing, and to investigate their antimicrobial resistance (AMR), potential virulence factors (VFs), and phylogenetic relationships. Both isolates were phenotypically confirmed to be susceptible to doxycycline, gentamicin, rifampicin, streptomycin, and trimethoprim–sulfamethoxazole, and no corresponding classical AMR genes were identified. However, several potential AMR-related genes (mprF, bepCDEFG, qacG, and adeF) and a mutation in the parC gene were detected. The analysis of the genotypes revealed 74 potential virulence genes, primarily involved in lipopolysaccharide synthesis and type IV secretion systems. Genomic comparison showed over 99% nucleotide identity between the Tunisian strains, B. melitensis bv. 1 16M and B. melitensis bv. 3 Ether. Five gene clusters, including three hypothetical proteins with 100% identity, were detected exclusively in the TATA and SBZ strains. Additionally, two unique gene clusters were identified in SBZ: a rhodocoxin reductase and another hypothetical protein. Both isolates were assigned to sequence types ST11 and ST89. Core-genome-based phylogenetic analysis clustered both strains with biovar 3 and ordered the Tunisian strains into two distinct groups: TATA within Tunisian Cluster 1 is closely related to strains from Egypt and Italy, while SBZ near MST Cluster 4 is more related to isolates from Austria and two outliers from Italy and Tunisia. This study provides the first genomic characterization of B. melitensis from aborted sheep in Tunisia and offers valuable insights into AMR, virulence, and phylogenetic distribution. Full article

Antimicrobial resistance is a threat to probiotic microorganisms due to their potential role in harboring and transmitting resistance genes. This study focuses on two Bifidobacterium species (B. animalis subsp. lactis and B. longum) by analyzing 657 Minimal Inhibitory Concentration (MIC) values extracted from research articles indexed in Scopus, PubMed, and Web of Science, published since 2014, and considering 17 different antibiotics. MIC values were used for descriptive statistical analysis (boxplots and violin plots) to evaluate both inter- and intraspecies distributions. The results showed an overall increase in MIC values compared to historical data, with B. longum exhibiting high resistance to tetracyclines and streptomycin—approximately 25% to 50% of the strains had MIC values > EFSA cut-offs. The violin plots revealed the presence of resistant subpopulations, particularly within B. longum. These findings support the relevance of longitudinal MIC analysis as a tool for detecting early shifts in antimicrobial susceptibility and highlight the importance of data-driven approaches for microbiological risk assessment in probiotic applications. Full article

The global population is rising at an alarming rate and is projected to reach 10 billion by 2050, necessitating a substantial increase in food production. However, the overuse of chemical pesticides, including antibacterial agents and synthetic fertilizers, poses a major threat to sustainable agriculture. This review examines the ecological and health impacts of antibacterial agents (e.g., streptomycin, oxytetracycline, etc.) in horticultural crops, focusing on their effects on non-target organisms such as beneficial microbes involved in plant growth promotion and resistance development. Certain agents (e.g., triclosan, sulfonamides, and fluoroquinolones) leach into water systems, degrading water quality, while others leave toxic residues in crops, leading to human health risks like dysbiosis and antibiotic resistance. To mitigate these hazards, sustainable alternatives such as integrated plant disease management (IPDM) and biotechnological solutions are essential. Advances in genetic engineering including resistance-conferring genes like EFR1/EFR2 (Arabidopsis), Bs2 (pepper), and Pto (tomato) help combat pathogens such as Ralstonia solanacearum and Xanthomonas campestris. Additionally, CRISPR-Cas9 enables precise genome editing to enhance inherent disease resistance in crops. Emerging strategies like biological control, plant-growth-promoting rhizobacteria (PGPRs), and nanotechnology further reduce dependency on chemical antibacterial agents. This review highlights the urgent need for sustainable disease management to safeguard ecosystem and human health while ensuring food security. Full article

Background and Objectives: Tuberculosis (TB) is one of the most common infectious diseases in developing countries. The resistance of the causative agent, Mycobacterium tuberculosis, to two or more first-line anti-TB drugs results in multidrug-resistant (MDR) TB, posing a serious challenge to the control of TB worldwide. This study was designed to determine the changes in drug resistance over time in TB strains isolated from patients in all departments of Uludağ University Hospital in western Türkiye. Materials and Methods: We retrospectively analyzed 104,598 clinical samples sent to our laboratory for the investigation of the presence of TB between 1996 and 2023. BACTEC 460 TB, BACTEC MGIT 960 culture systems and Löwenstein–Jensen medium were used for the culture of these samples. The susceptibility of M. tuberculosis complex strains grown in culture to isoniazid (INH) (0.1 μg/mL), rifampicin (RIF) (1.0 μg/mL), ethambutol (ETB) (5.0 μg/mL) and streptomycin (SM) (1.0 μg/mL) antibiotics was studied according to the manufacturer’s recommendation. Results: Out of 104,598 patient samples, 2752 (2.6%) were culture-positive, and the susceptibility test results of 1869 of these were analyzed. Of the isolates, 358 (19.2%) were found to be resistant to at least one first-line drug, i.e., INH, RIF, ETB, or SM. In addition, 2.9% were resistant to two or more first-line drugs. Conclusions: Drug susceptibility testing is essential to ensure the optimal treatment and control of drug-resistant TB strains. This study highlights the value of ongoing efforts to control tuberculosis drug resistance in the fight against this disease. Full article

The emergence and dissemination of antibiotic-resistant Klebsiella pneumoniae, particularly those are extended-spectrum beta-lactamase (ESBL) producers, thought to pose a serious threat to global health. This study aimed to isolate and identify the ESBL-producing K. pneumoniae from captive wild and migratory birds in Bangladesh along with their antimicrobial resistance characteristics. In this investigation, standard bacteriological methods were used to detect K. pneumoniae in 219 fecal samples. The positive isolates were confirmed by PCR and antibiotic susceptibility testing was performed by disk diffusion method. K. pneumoniae was detected in 93 (42.47%, 95% CI: 35.8–49.3) out of 219 fecal samples. The prevalence of K. pneumoniae was higher in captive wild birds (50%; 40/80) compared to migratory birds (38.1%; 53/139). The isolates showed high resistance to ampicillin (69.9%) and streptomycin (64.5%). Conversely, the highest sensitivity was recorded for trimethoprim-sulfamethoxazole (84.95%), followed by levofloxacin (79.57%) and gentamicin (69.89%). Molecular screening revealed that all positive isolates harbored bla_TEM-1&2 encoding genes, with 45.2% and 15.1% carried bla_SHV-1 and bla_OXA-1,4&30, respectively. Additionally, resistance genes strA (30.1%), tetA (9.7%), and sul1 (9.7%) were detected. The Multiple Antibiotic Resistance (MAR) index ranged from 0.18 to 0.64, with 63.4% of isolates classified as MDR. The isolation of MDR and ESBL producing K. pneumoniae from captive wild and migratory birds suggests that these birds may serve as reservoirs for the spread of these bacteria, potentially impacting public health in the study region. Full article

Tuberculosis remains a significant health issue in Mexico, which has one of the highest incidence rates in the Americas. This study aimed to analyze the circulating sublineages, spoligotypes, drug resistance, and transmission patterns of Mycobacterium tuberculosis in Mexico’s Central Western region using whole-genome sequencing. Seventy-seven Mycobacterium tuberculosis strains underwent phenotypic drug susceptibility testing via MGIT. Genotypic resistance was assessed with TB-Profiler and Mykrobe, while phylogenetic relationships were reconstructed using Snippy and RaxML. SpoTyping identified circulating SITs and families, with a 5-SNP threshold defining genomic transmission clusters. The predominant sublineages were 4.1.1.3 (X-type, n = 19) and 4.1.2.1 (LAM, n = 11), with rare sublineages (EAI5, EAI2-Manila, and Beijing) also observed. Resistance to at least one first-line drug was found in 63.3% of strains, with streptomycin mono-resistance (24.5%) being notable. Multidrug-resistant TB was identified in 16.3% (n = 8) of strains. Five genomic clusters, involving 18.7% of strains, were identified. This study highlights the sublineage diversity in Mexico, emphasizing its importance in global databases and resistance research. The findings, such as SIT47 in GC1, underscore the value of localized genomic studies for effective TB control. Full article

Lentil is a nutritionally valuable legume crop, rich in protein, carbohydrates, amino acids, and vitamins, and is also used as green manure. Symbiotic nitrogen fixation (SNF) plays a crucial role in lentil growth and development, yet there is limited research on isolating and identifying lentil rhizobia related to nodulation and nitrogen fixation. This study employed tissue block isolation, line purification, and molecular biology to isolate, purify, and identify rhizobial strains from lentils, analyzing their physiological characteristics, including bromothymol blue (BTB) acid and alkali production capacity, antibiotic resistance, salt tolerance, acid and alkali tolerance, growth temperature range, and drought tolerance simulated by PEG6000. Additionally, the nodulation capacity of these rhizobia was assessed through inoculation experiments using the identified candidate strains. The results showed that all isolated rhizobial strains were resistant to Congo red, and nifH gene amplification confirmed their potential as nitrogen fixers. Most strains were positive for H₂O₂ and BTB acid and base production, with a preference for alkaline environments. In terms of salt tolerance, the strains grew normally at 0.5–2% NaCl, and six strains were identified as salt stress resistant at 4% NaCl. The temperature range for growth was between 4 °C and 49 °C. Antibiotic assays revealed resistance to ampicillin and low concentrations of streptomycin, while kanamycin significantly inhibited growth. Two drought-tolerant strains, TG25 and TG55, were identified using PEG6000-simulated drought conditions. Inoculation with candidate rhizobial strains significantly increased lentil biomass, highlighting their potential for enhancing crop productivity. Full article

Antibiotic-resistant bacteria pose problems for infection prevention and treatment, so developing new procedures or substances against infection is mandatory. Silver nanomaterials are among the more promising antibacterial agents. Herein, we describe the biogenic synthesis of silver nanoparticles (AgNPs) using culture broths from an undescribed species of Lysinibacillus. Culture broths with or without NaCl and from the exponential and stationary growth phases produced four AgNP types. Nanoparticles’ shapes were quasi-spherical, with core sizes of 7.5–14.7 nm and hydrodynamic diameters of 48.5–80.2 nm. All the AgNPs contained Ag⁰ crystals and some AgCl ones. Moreover, their coronas presented different proportions of carbohydrates, proteins, and aliphatic compounds. The AgNPs were good antibacterial agents against six bacterial species, three Gram-positive and three Gram-negative, with MICs of 0.3–9.0 µg/mL. Their activity was higher against the Gram-negative bacteria and particularly against Pseudomonas aeruginosa. These AgNPs acted synergistically with several of the fifteen tested antibiotics. Interestingly, AgNP combinations with some of these inhibited the growth of antibiotic-resistant bacteria, as in the case of S. epidermidis for streptomycin and S. aureus for colistin. The ROS production by E. coli and S. aureus when treated with most AgNPs suggested different mechanisms for bacterial killing depending on the AgNP. Full article

Probiotics exert beneficial effects on health improvement, infection prevention, and disease management. This study investigated the probiotic characteristics and safety parameters of Levilactobacillus brevis ZG2488, a novel strain isolated from healthy human feces. The strain exhibited robust tolerance to simulated gastrointestinal conditions, maintaining survival rates of 87.20% in artificial gastric juice (pH 3.0; 3 h) and 95.32% in 0.3% bile salt (24 h). Notably, L. brevis ZG2488 displayed superior microbial adhesion properties with high cell surface hydrophobicity (87.32%), auto-aggregation (81.15% at 24 h), and co-aggregation capacities with Escherichia coli ATCC 43895 (63.90%) and Salmonella typhimurium SL1344 (59.28%). Its adhesion to HT-29 cells (7.15%) surpassed that of the reference strain Lactobacillus rhamnosus GG (1.26%). Antimicrobial testing revealed broad-spectrum inhibitory effects against multidrug-resistant Klebsiella pneumoniae NK04152 and other pathogens. Comprehensive safety assessments confirmed the absence of hemolytic or DNase activity, along with appropriate antibiotic susceptibility to most antibiotics, except kanamycin, streptomycin, vancomycin, and penicillin G. Furthermore, L. brevis ZG2488 significantly enhanced nitric oxide production and upregulated the gene expression of nitric oxide synthase (iNOS) and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) in RAW264.7 macrophages. These findings underscore L. brevis ZG2488 as a promising probiotic candidate with functionality in pathogen inhibition and immune modulation. Full article

The rapid increase in drug resistance in recent years has become a significant global public health concern. Escherichia coli are ubiquitous bacteria, widely distributed in various environments. This study isolated a bacterial strain (HD-593) from diseased Chinese soft-shelled turtles (Pelodiscus sinensis). The bacterium was identified based on morphology, biochemical tests, and 16S rRNA sequencing, confirming it as E. coli. Drug susceptibility tests revealed that the HD-593 strain was highly resistant to ceftriaxone, enrofloxacin, doxycycline, sulfadiazine, gentamicin, neomycin, florfenicol, carbenicillin, cefradine, erythromycin, penicillin, ampicillin, midecamycin, and streptomycin. Resistance gene analysis confirmed the presence of quinolone resistance genes (oqxA and oqxB), aminoglycoside resistance genes (aac(3)-II and aphA1), a β-lactam resistance gene (blaTEM), and an acylaminol resistance gene (floR) in HD-593. The median lethal dose (LD50) of HD-593 for P. sinensis was 6.53 × 10⁵ CFU/g. Biochemical analysis of serum revealed that HD-593 infection caused a significant reduction in total protein, albumin, and globulin levels, while markedly increasing the levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Histopathological analysis revealed severe intestinal damage characterized by villi detachment and muscle cell necrosis. Additionally, extensive splenocyte necrosis with nuclear marginalization, glomerular swelling, and pronounced hepatic steatosis accompanied by distended sinusoids were observed. This study identified a multidrug-resistant E. coli strain from deceased P. sinensis, suggesting that drug resistance genes may circulate in aquaculture ecosystems, posing potential risks to aquaculture. Full article

Intensive fish farming worldwide has increased reliance on antibiotics to control bacterial pathogens, raising concerns about antimicrobial resistance (AMR) in aquaculture. These resistant bacteria can persist and pass through the food supply chain, from farms to consumers. Despite this risk, antimicrobial resistance genes (ARGs) in aquaculture environments and fish products have not been elucidated. This study aimed to detect ARGs found in the Asian seabass (Lates calcarifer), an economically important fish in Thailand, collected from farms, fish container vehicles, and markets, using Nanopore metagenomic sequencing. We detected multiple ARGs in all sample types. Water samples harbored the rpsL gene conferring streptomycin resistance. Container samples exhibited the highest diversity of ARGs, including multiple beta-lactamases and the rsmA gene, conferring resistance to fluoroquinolones, diaminopyrimidines, and phenicol antibiotics. Fish samples generally lacked ARGs, except for one sample harboring rsmA. Non-metric multidimensional scaling revealed distinct microbial communities in water, compared with those found in container and fish samples, indicating potential cross-contamination during handling or storage. Our findings emphasize that containers could be critical control points for minimizing AMR spread. Overall, this study highlights the interconnection between environmental, fish, and human health, highlighting the importance of integrated AMR surveillance and management in aquaculture systems. Full article

Clinical endometritis is a leading cause of infertility in she-camels. We commonly isolate E. coli from camel uteri with and without endometritis during our routine diagnosis of conception failure. From an epidemiological standpoint, it is critical to know if certain E. coli genotypes and virulence factors are specifically associated with endometritis. Thus, we aimed to compare the abundance of virulence elements and genotypes in uterine E. coli from camels with and without endometritis and understand their evolution. For this investigation, we retrieved data from the genomes of 28 E. coli isolates from humans, cats, dogs, horses, cows, and birds and 14 sequenced genomes of camel uterine E. coli isolates. We found no specific E. coli genotype or virulence factor associated with endometritis. Instead, multiple genotypes and high genomic diversity were observed. Moreover, horizontal gene transfer driven by genomic islands and plasmids contributed to the genetic diversity of the isolates, resulting in the acquisition of virulence genes, metabolic characteristics, and antibiotic resistance determinants to trimethoprim, sulfonamide, streptomycin, and tetracycline. Additionally, the phylogenetic position of the E. coli isolates from camel uteri suggests that they originated from intestinal strains. In conclusion, there was no evidence of E. coli specialization, and E. coli alone may not be able to develop endometritis, as other factors are required. Also, we elucidated the mechanism behind the diversity of the gene repertoire of E. coli isolated from camel uteri. These findings provide insight into the evolutionary origins of E. coli isolates from camel uteri. Full article