Search Results (62)

Antimicrobial resistance has intensified the search for novel antimicrobial and wound-healing agents. Ludwigia octovalvis (Jacq.) P.H. Raven is traditionally used to treat infections, inflammation, and skin disorders, although its in vitro biotechnological potential remains largely unexplored. This study reports the first successful establishment of L. octovalvis callus cultures, their characterization by gas chromatography-mass spectrometry (GC-MS), and the evaluation of their antimicrobial and wound-healing activities. Friable calluses were induced from leaf and node explants of axenic seedlings using combinations of 6-benzylaminopurine (BAP), kinetin (KIN), 2,4-dichlorophenoxyacetic acid (2,4-D), and α-naphthaleneacetic acid (NAA). Optimal callus induction was achieved in leaf explants cultured on full-strength Murashige and Skoog (MS) medium supplemented with BAP (4.44 µM) and 2,4-D (0.45 µM). After six months of subculture, the calluses showed morphological uniformity and stable biomass production. Growth kinetics followed a specific growth rate of 0.047 d⁻¹ and a doubling time of 14.54 days. GC-MS analysis identified fatty acids and phytosterols as the main components. The ethyl acetate extract significantly improved wound healing in vivo, while the methanolic extract exhibited antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). These findings demonstrate that L. octovalvis callus cultures constitute a sustainable source of bioactive compounds with promising therapeutic potential. Full article

Background/Objectives: We evaluated the diagnostic performance of the Alifax Molecular Mouse (MM) sepsis panel for rapidly directly detecting pathogens and resistance genes in positive blood culture broths. Methods: In this prospective single-center study, 40 positive blood culture specimens were analyzed using four MM cartridges targeting Gram-positive and -negative bacteria and major antimicrobial resistance genes. The results were compared with those obtained using the routine microbiological protocol, including organism identification using the MALDI Biotyper system and antimicrobial susceptibility testing using the VITEK 2 and MicroScan WalkAway systems. Additionally, the MM panel results were compared with those obtained using the FilmArray BCID2. Results: Compared with the routine protocol, the MM panel achieved a positive percent agreement (PPA) of 89.5% (34/38; 95% confidence interval [CI], 75.9–95.8%) for bacterial identification, indicating moderate-to-good diagnostic performance. For antimicrobial resistance gene detection, the PPA was 92.1% (35/38; 95% CI, 79.2–97.3%). Compared with the FilmArray BCID2, the overall agreement of the MM panel was 89.4% (34/38) for bacterial identification and 84.2% (32/38) for antimicrobial resistance gene detection. The MM panel generated clinically actionable results within 1 h (mean turnaround time, 55.5 min; 95% CI, 55.1–55.9 min), substantially reducing the turnaround time compared with the conventional microbiological workflow, which requires 1.5–2 days for subculture and automated antimicrobial susceptibility testing. Conclusions: The MM sepsis panel enabled rapid, direct identification of bloodstream pathogens and key antimicrobial resistance markers from positive blood cultures, substantially reducing turnaround time and exhibiting its potential as an adjunct to routine microbiological workflows. Full article

Background/Objectives: Bloodstream infections (BSIs) are a global healthcare issue associated with high mortality rates. Rapid diagnosis is of importance for the early selection of targeted therapy to improve patient outcomes. The use of rapid molecular assays with positive blood culture (BC) allows the identification (ID) of pathogens and the most relevant resistance determinants (RDs) in a shorter turnaround time, compared to standard culture. In this study, the performances of a new syndromic panel to determine the IDs and RDs of Gram-negative (GN) and Gram-positive (GP) bacteria were investigated in comparison with a standard-of-care (SoC) workflow. Methods: Two hospitals processed residual positive BC samples from non-replicated patients using Molecular Mouse (MM) Sepsis panels (Alifax, Padova, Italy) for GP ID, GN ID and RD detection. Results were compared with an SOC workflow based on subculture, ID by MALDI-ToF mass spectrometry, phenotypic antibiogram, and real-time PCRs for RDs from isolated colonies. Results: A total of 140 and 136 residual positive BC samples were found to be valid for MM-ID and RD, respectively, yielding 76 GN and 76 GP species. Overall ID agreement at the species level was 136/152 (89%). RD agreement was 144/146 (99%). Regarding GN and GP species, ID agreement was 68/76 (89%) and 70/76 (92%), respectively. Conclusions: MM showed high sensitivity in RD detection; however, some discrepancies with results of the SoC workflow were observed, represented by reduced sensitivity for some species-specific IDs. Panel size and compact instrument dimension can be seen as the principal advantage of this modular molecular assay for the rapid detection of pathogens responsible for BSIs. Full article

In vitro-cultured plant calli are colonized by diverse endophytes. As these endophytes are inherited from the maternal plant and appear to be highly dependent on the eco-niche of the host cells, they have been termed host-dependent endophytes (HDEs). HDEs occupy the most intimate microbial environment of plant cells. Nevertheless, our understanding of HDEs and their microenvironmental effects on host plants remains limited due to their cultivation-recalcitrant nature. In this study, grapevine (Vitis vinifera L. × V. labrusca L.) callus was subjected to long-term cultivation in media containing different antibiotics (Q: penicillin; L: streptomycin; Z: nystatin) with the intention of creating grapevine calli with different HDEs. The treated calli were then transferred to an antibiotic-free medium for continuous cultivation. After three cycles of subculture over a total period of 45 days, the endophytic microbiota of the grapevine calli were profiled and their physiological parameters were analyzed. Our results revealed that antibiotic treatments can effectively shape HDEs and create distinct bacterial and fungal HDE microbiota in grapevine calli. Compared to treatment without antibiotics (CK), the Q-treated callus contained more Gram-positive bacterial HDEs but fewer Gram-negative and stress-resistant bacterial HDEs, whereas the Z-treated callus had fewer Gram-positive bacterial HDEs and more Gram-negative, stress-resistant and potentially pathogenic bacterial HDEs. More importantly, grapevine calli with different HDE communities showed varying physiological traits such as respiratory rate, peroxidase activity and total sugar content. Correlative analyses further revealed the functional associations between HDE taxa and callus traits. This work provides an example for studying and utilizing plant HDEs. Full article

Chelerythrine (CHE) is a naturally occurring benzophenanthridine alkaloid obtained from plants such as Chelidonium majus L. It has received notable attention in pharmacology and microbial control because of its broad-spectrum activity and marked anti-inflammatory, apoptosis-inducing, and antibacterial effects. In this study, Bacillus tropicus, which frequently presents in the soil environment, was selected as the target microorganism to systematically examine the dose-dependent inhibitory influence of CHE on its growth curve, biofilm development, and survival rate. Furthermore, by simulating an antibiotic pressure environment in vitro, the original strain was subjected to continuous subculturing (30 times), and a highly drug-resistant B. tropicus strain capable of stable growth under high concentrations of CHE (300 mg/L) was successfully acclimated. After that, transcriptomics analysis was employed to compare the genetic differences between the wild-type bacterium and drug-resistant bacterium to determine how bacterial cells are able to resist CHE. A total of 868 genes in the CHE-resistant bacterium were revealed to be more active, while 539 genes were less active. These results indicate that the CHE resistance characteristics of the strain may be related to the adjustment of its sugar metabolism pathway and the biofilm formation pathway. As a widely used biological control bacterial strain, the successful acclimation of the B. tropicus strain with resistance to CHE has made it possible to use the combined formulation of these two agents for the prevention and control of plant diseases. Full article

The indiscriminate use of antibiotics in food-producing animals serves as a major catalyst for the emergence of antibiotic-resistant infections. This study aimed to assess the genetic diversity and antibiotic resistance of Enterobacterales in animal-derived foods. A total of 905 animal-derived food samples, including meat, dairy, poultry, fish, and environmental sources, were collected from various locations in Pakistan. Isolates were confirmed through selective subculturing, morphological, biochemical, and MALDI-TOF analysis, followed by antibiotic susceptibility testing. Subsequently, PCR-based detection of antibiotic resistance genes and virulence-associated genes. Overall, a total of 263 (29.06%) Enterobacterales were identified, as follows: 58.55% (154/263) E. coli, 6.84% (18/263) K. pneumoniae, 21.29% (56/263) P. mirabilis, and 13.30% (35/263) Salmonella spp. Isolates showed a varying resistance pattern against different studied antibiotics, e.g., beta-lactams and inhibitors, ciprofloxacin, and tetracycline, while colistin and tigecycline remained most effective. All the isolates displayed an array of antibiotic resistance and virulence-associated genes. Particularly significant (<0.05) co-existence of bla_NDM and mcr-1 was observed among the Enterobacterales isolated from various animal-derived foods. This study underscores the need to monitor Enterobacterales in animal-derived foods, especially in developing countries, to curb the spread of resistant pathogens and ensure effective food safety measures. Full article

Bacterial antibiotic resistance (AR) has become a critical global health threat. AR is mainly driven by adaptive resistance mutations and the horizontal gene transfer of resistance genes, both of which are enhanced by genome recombination. We previously discovered that genome recombination-mediated tRNA upregulation is important for AR, especially in the early stages. RecA is a crucial bacterial factor mediating genome recombination and the DNA damage response. Therefore, RecA inhibitors should be effective in reducing AR. In this study, we found that BRITE-338733 (BR), a RecA inhibitor, can prevent ciprofloxacin (CIP) resistance in subculturing Escherichia coli strain BW25113 in the early stages (up to the 7th generation). In the presence of BR, the tRNA was decreased, so the bacteria cannot evolve resistance via the tRNA upregulation-mediated AR mechanism. The RecA expression level was also not increased when treated with BR. Transcriptome sequencing revealed that BR could inhibit oxidative phosphorylation, the electron transport chain process, and translation, thereby reducing the bacterial energy state and protein synthesis. Also, the effective concentrations of BR do not harm human cell viability, indicating its clinical safety. These findings demonstrate that BR effectively delays the emergence of spontaneous AR by targeting RecA-mediated pathways. Our findings shed light on a new strategy to counteract clinical AR: applying BR with the antibiotics together at the beginning. Full article

Purpose: The adenoid microbiota plays a key role in adenoid hypertrophy (AH). This study explored the molecular epidemiology and antimicrobial resistance of Haemophilus. Influenzae (H. influenzae) strains in pediatric AH patients. Methods: Retrospective analysis of pediatric AH patients undergoing endoscopic adenoidectomy. Adenoid tissue samples were cultured to screen for pathogens. H. influenzae strains were identified by 16S rRNA sequencing and serotyped via q-PCR. Multilocus sequence typing (MLST) and ftsI gene analysis were conducted using PubMLST. β-lactamase genes (bla_TEM-1, bla_ROB-1) were detected by PCR, and antibiotic susceptibility testing (AST) was performed using the Etest method. For imipenem-resistant strains, the acrRAB efflux pump gene cluster and ompP2 porin gene were sequenced and compared with those of the wild-type strain Rd KW20. Results: Over 8 months, 56 non-duplicate H. influenzae strains were isolated from 386 patients. The detection rate was highest in children under 5 years (30.5%) compared to those aged 5–10 years (13.4%) and 10–15 years (8.7%). Of 49 sub-cultured strains, all were non-typeable H. influenzae (NTHi). MLST identified 22 sequence types (STs) and 13 clonal complexes (CCs), with CC11 (26.5%), CC3 (14.3%), and CC107 (14.3%) being predominant. Common STs included ST103 (22.4%), ST57 (10.2%), and ST107 (10.2%). Most strains belonged to the ftsI group III-like+ (57.1%). β-lactamase positivity was 98.0% (48/49), with bla_TEM-1 (95.9%) and bla_ROB-1 (18.4%) detected. AST showed low susceptibility to ampicillin (10.2%), amoxicillin–clavulanate (34.7%), azithromycin (12.2%), and trimethoprim–sulfamethoxazole (14.3%). Among the β-lactamase-positive strains, 44/48 were β-lactamase-positive ampicillin-resistant (BLPAR); none were β-lactamase-negative ampicillin-resistant (BLNAR). Imipenem susceptibility was 91.8% (45/49). No carbapenemases were found in the imipenem-resistant strains, but mutations in acrRAB (88.12–94.94% identity) and ompP2 (77.10–82.94% identity) were observed. Conclusions: BLPAR NTHi strains of CC11 are major epidemic strains in pediatric AH. Imipenem resistance in H. influenzae likely results from porin mutations rather than carbapenemase activity. Enhanced surveillance of H. influenzae’s role in AH and its resistance patterns is warranted. Full article

Pinus massoniana Lamb. (masson pine) is a critical species for afforestation in southern China but faces severe threats from pine wilt disease (PWD) caused by Bursaphelenchus xylophilus. To accelerate disease-resistant breeding, this study investigated the effects of cryopreservation on the embryonic capacity of the embryogenic callus as well as the effects of abscisic acid (ABA), polyethylene glycol 8000 (PEG 8000) and phytagel concentration on the somatic embryo’s maturation and germination. Furthermore, the impact of transplanting substrates on the survival and growth of regenerated plantlets were evaluated. The results showed that cryopreservation at −196 °C effectively maintained the embryogenic potential of the callus, with post-thaw tissues exhibiting superior somatic embryo maturation capacity compared to the long-term subcultured callus (38.4 vs. 13.2 embryos/mL). Key maturation parameters were systematically optimized: ABA concentration at 6 mg/L in the suspension culture maximized embryo yield of 24.1 somatic embryos/mL, while PEG 8000 at 130 g/L in solid medium achieved peak embryo production of 38.4 somatic embryos/mL, and the maximum of 26.6 somatic embryos/mL when the concentration of phytagel was 3.5 g/L. The highest germination rate of 29.8% was observed with 130 g/L PEG in the maturation medium. The highest survival rate (56.5%) and maximum plant height (22.3 cm) after 12 months of transplantation were achieved in substrates consisting of soil and vermiculite, which outperformed those containing varying proportions of mushroom residue. This study establishes a scalable protocol for the mass propagation of PWD-resistant P. massoniana, integrating cryopreservation and maturation media optimization, which offers dual benefits for disease-resistant breeding and sustainable germplasm conservation. Full article

Background: Nowadays, the microbial degradation of cellulose represents a new perspective for reducing cellulose waste from industry and households and at the same time obtaining energy sources. Methods: We isolated and enriched two aerobic (at 37 °C and 50 °C) and one anaerobic microbial consortium from an anaerobic bioreactor for biogas production by continuous subculturing on peptone cellulose solution (PCS) medium supplemented with 0.3% treated or untreated Whatman filter paper under static conditions. Samples were taken every 7 days until day 21 to determine the percentage of cellulose biodegradation. We determined the antimicrobial resistance of aerobic and anaerobic consortia and some single colonies by disc diffusion method, against 42 clinically applied antibiotics. PCR analyses were performed to search for the presence of eight genes for cellulolytic activity and nine genes for antibiotic resistance. By metagenomics analysis, the bacterial and fungal genus distributions in the studied populations were determined. Results: Aerobes cultured at 50 °C degraded cellulose to the greatest extent (47%), followed by anaerobes (24–38%) and aerobes (8%) cultured at 37 °C. The bacterial sequence analysis showed that the dominant phyla are Bacillota and Bacteroidetes and genera—Paraclostridium, Defluvitalea, Anaerobacillus, Acetivibrio, Lysinibacillus, Paenibacillus, Romboutsia, Terrisporobacter, Clostridium, Sporanaerobacter, Lentimicrobium, etc. in a different ratio depending on the cultivation conditions and the stage of the process. Some of these representatives are cellulolytic and hemicellulolytic microorganisms. We performed lyophilization and proved that it is suitable for long-term storage of the most active consortium, which degrades even after the 10th re-inoculation for a period of one year. We proved the presence of ssrA, ssrA BS and blaTEM genes. Conclusions: Our findings demonstrated the potential utility of the microbial consortium of anaerobes in the degradation of waste lignocellulose biomass. Full article

This study explores the Potaxie, Fifes, and Tilinx subcultures on TikTok, examining their origins, characteristics, and cultural significance. Originating from a viral video in 2020, the Potaxie subculture emerged within the Spanish-speaking LGBTQ+ community and evolved to symbolise inclusivity and gender equality. Potaxies use vibrant aesthetics influenced by Japanese and Korean pop culture to express their identities and resistance. In contrast, Fifes, associated with cisgender heterosexual men, embody traditional patriarchal values, often sexist and homophobic, creating a narrative of resistance between the groups. The Tilinx, symbolic descendants of the Potaxies, are inspired by ballroom culture and drag houses, with “Potaxie mothers” continuing the fight for inclusion and diversity. Using a mixed-methods approach, including quantitative analysis through the TikTok API and qualitative content analysis via MAXQDA and Python, this study provides a comprehensive understanding of the subculture that accumulates over 2.3 billion interactions. The findings highlight how TikTok serves as a platform for identity construction, cultural resistance, and the redefinition of social norms. Additionally, the study examines how digital platforms mediate intersectional experiences, favouring certain types of content through algorithms, and how participants navigate these opportunities and constraints to express their intersecting identities. The implications for communication strategies, youth policies, educational plans, and research on the commercialization of these subcultures are profound, offering insights into the transformative potential of social media in shaping contemporary cultural and social narratives. Full article

Introduction: Antimicrobial resistance (AMR) has surfaced as a critical challenge to public health on a global scale. The precise and swift identification of resistance to antimicrobial agents, along with timely and suitable antimicrobial therapy paired with effective stewardship practices, is crucial for managing the rise and dissemination of antimicrobial resistance. The objective of our investigation was to outline the antimicrobial resistance profile of Staphylococcus spp., a significant contributor to canine otitis, a prevalent condition in dogs, isolated in Western Romania. Methods and Materials: All data were collected from clinical cases of canine otitis externa which presented at the University Clinic of the Faculty of Veterinary Medicine in Timișoara/Romania. A clinical evaluation was conducted, from which era swabs are usually collected and sent for analysis at the laboratory. Laboratory analysis included the microbiological examination for identifying Staphylococcus spp. and determining antibiotic susceptibility phenotypes. Statistical analysis was implemented on all data that were collected. The ear swabs were processed with standard procedures for cultivating and identifying bacteria. The resulting subcultures were processed to determine the staphylococcal species on the GP ID Cards of the Vitek^® 2 automatic system. The antimicrobial susceptibility profiles were detected by the Vitek^® 2 system using an AST-GP80 card. These isolated Staphylococcus spp. strains were further processed by real-time PCR and PCR-RFLP. Results: Of all the auricular exudate samples analyzed, 76 were positive for Staphylococcus spp. (59.38%). Within these, in 82% of auricular samples, six distinct Staphylococcus spp. were identified (Staphylococcus (S.) pseudintermedius, S. intermedius, S. hyicus, S. delphiny, S. shleiferi, and S. aureus). Our data indicate that the PCR-RFLP assay is a practical approach to S. pseudintermedius identification, allowing for discrimination from the other Staphylococcus Intermedius Group (SIG) species and important staphylococcal pathogens of dogs. The highest frequency of resistant S. pseudintermedius isolates was detected against tetracycline (21/34; 61.76%; p-value 0.003), gentamicin (20/34; 58.82%), and kanamycin (20/34; 58.82%). Conclusions: These results are essential to guide the prudent use of antibiotics in veterinary medicine. They will also help design efficient control strategies and measure their effectiveness. Full article

Emerging evidence suggests that cancer stemness plays a crucial role in tumor progression, metastasis, and chemoresistance. Upon exposure to internal or external stress, ribosomes stand sentinel and facilitate diverse biological processes, including oncological responses. In the present study, ribosome-inactivating stress (RIS) was evaluated for its modulation of cancer cell stemness as a pivotal factor of tumor cell reprogramming. Based on the concept of stress-responsive cancer cell stemness, we addressed human intestinal cancer cell line-based off-the-shelf spheroid cultures. Intestinal cancer cell line-based spheroids exhibited heightened levels of CD44⁺CD133⁺ cancer stemness, which was improved by chemical-induced RIS. Further evaluations revealed the potential of these stress-imprinted spheroids as a platform for chemoresistance screening. Compared to adherent cells, stemness-improved spheroid cultures displayed reduced apoptosis in response to 5-fluorouracil (5-FU), a frontline chemotherapeutic agent against colorectal cancer. Moreover, serial subcultures with repeated RIS exposure maintained and even enhanced cancer stemness and chemoresistance patterns. In particular, isolated CD44⁺CD133⁺ cancer stem cells exhibited higher chemoresistance compared to unsorted cells. To elucidate the mechanisms underlying RIS-induced stemness, RNA-seq analysis identified Wnt signaling pathways and stemness-associated signals as notable features in spheroids exposed to RIS. Loss-of-function studies targeting connective tissue growth factor (CTGF), a negative regulator of Wnt signaling, revealed that CTGF-deficient spheroids exhibited improved cancer stemness and resistance to 5-FU, with RIS further enhancing these effects. In conclusion, this proof-of-concept study demonstrates the feasibility of leveraging stress-responsive cancer stemness for the development of spheroid-based platforms for chemoresistance evaluation and elucidation of pathophysiological processes of colorectal tumorigenesis under environmental stress. Full article

Antimicrobial peptides represent a promising alternative to traditional drugs in relation to cost, toxicity, and, primarily, the growing problem of drug resistance. Here, we report on the activity against HSV-1 and HSV-2 of a previously described wide-spectrum synthetic decapeptide, Killer Peptide (KP). As determined by plaque reduction assays, treatment with KP at 100 μg/mL resulted in a reduction in the viral yield titer of 3.5 Logs for HSV-1 and 4.1 Logs for HSV-2. Further evaluation of KP antiviral activity focused on the early stages of the virus replicative cycle, including the determination of the residual infectivity of viral suspensions treated with KP. A direct effect of the peptide on viral particles impairing virus absorption and penetration was shown. The toxicity profile proved to be extremely good, with a selectivity index of 29.6 for HSV-1 and 156 for HSV-2. KP was also active against acyclovir (ACV)-resistant HSV isolates, while HSV subcultures in the presence of sub-inhibitory doses of KP did not lead to the emergence of resistant strains. Finally, the antiviral action of KP proved to be synergistic with that of ACV. Overall, these results demonstrate that KP could represent an interesting addition/alternative to acyclovir for antiviral treatment. Full article

Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases affecting banana cultivation worldwide. Although Foc tropical race 4 (TR4) has not yet been identified in Brazilian production areas, the damage caused by races 1 and subtropical 4 is the main cause of production losses, especially affecting cultivars of the Prata subgroup. Thus, the induction of somaclonal variation is a promising strategy in biotechnology to generate genetic variability and develop resistant varieties. This study aimed to induce somaclonal variation in the Prata Catarina cultivar (AAB genome) using successive subcultures in Murashige and Skoog (MS) medium enriched with the plant regulator Thiadizuron (TDZ) at two concentrations: 1 and 2 mg/L. After evaluating the symptoms, we selected 13 resistant somaclones that were not infected by the fungus. Histochemical and histological analyses of the somaclones indicated possible defense mechanisms that prevented colonization and/or infection by Foc, such as intense production of phenolic compounds and the presence of cellulose and callose in the roots. Some somaclones showed no pathogen structures in the xylem-conducting vessels, indicating possible pre-penetration resistance. Furthermore, molecular studies indicated that the genetic alterations in the somaclones may have induced resistance to Foc without compromising the agronomic characteristics of the commercial genotype. Full article