Concentrations Of Kanamycin Research Articles

Visual detection of kanamycin with functionalized Au nanoparticles.

A simple and rapid colorimetric detection strategy, based on hydrogen bond identification of 6-thioguanine (6-TG) functionalized Au nanoparticles (AuNPs), is proposed for highly selective and sensitive determinationof kanamycin (KA). In this strategy, the hydrogen bond interaction between 6-TG and kanamycin induces AuNPs to agglomerate, with a consequent color change of AuNPs from wine red to purple or even blue. The kanamycin concentrations can be quantified by employing UV-vis spectrophotometer. The results display that kanamycin concentrations (0.005 to 18µM) are linearly related to A620/A520 (the absorbance ratio of 620nm and 520nm) with a LOD of 1.8nM and a LOQ of 5.9nM (S/N = 3). This strategy also reveals a high degree of selectivity among a series of common interfering species. Moreover, the strategy can be employed to detect trace amounts of kanamycin in real-life samples, and it shows satisfying resultscompared with high performance liquid chromatography. In general, this developed strategy is facile and inexpensive without the need for complex processing procedures and expensive instruments. In addition, this work may further exploit detection strategies for other organic contaminants, as well as make a strong contribution to the development of the colorimetric method.

Sonication-assisted Rhizobium radiobacter-mediated genetic transformation of Indian Lotus (Nelumbo nucifera Gaertn.).

This study aimed to develop a reliable and efficient genetic transformation method for the ornamental Indian Lotus (Nelumbo nucifera Gaertn.) using the sonication-assisted Rhizobium radiobacter-mediated transformation technique. To conduct the transformation, shoot apical meristem explants were infected with Rhizobium radiobacter (synonym Agrobacterium tumefaciens) strain LBA 4404 containing a binary vector pBI121 that harbours the GUS reporter gene (uidA) and kanamycin resistance gene nptII for plant selection. To improve the transformation efficiency, we optimized parameters such as bacterial cell density, sonication duration, infection time, co-cultivation duration, acetosyringone concentration, cefotaxime, and kanamycin concentrations. Sonication treatment at 42kHz for 90s recorded the highest transformation efficiency. The selection of regenerated plantlets was performed on a kanamycin-supplemented selection medium. The putative transformants showed GUS expression in the leaves and petioles. The presence of the GUS gene was also confirmed in the putative transformants through PCR, with the appearance of the expected amplicon size of 520bp. The presence of nptII was confirmed by PCR in the putatively transformed plants with an amplicon size of 530bp. The maximum regeneration frequency obtained was 72.66%, and the highest transformation efficiency achieved was 9.0% in the Indian Lotus.

Use of stable isotope combined with intact cell lipidomic by routine MALDI mass spectrometry analysis for rapid drug susceptibility assay in mycobacteria.

Rapid, accurate, and easy-to-perform diagnostic assays are required to address the current need for the diagnosis of resistant pathogens. That is particularly the case for mycobacteria, such as the human pathogen Mycobacterium tuberculosis, which requires up to 2weeks for the determination of the drug susceptibility profile using the conventional broth microdilution method. To address this challenge, we investigated the incorporation of deuterium, the stable isotope of hydrogen, into lipids as a read out of the drug susceptibility profile. Deuterium is incorporated into newly synthesized proteins or lipids in place of hydrogen as bacterial cells grow, increasing the mass of the macromolecules, which can then be observed via matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). As proof-of-concept, we used the non-pathogenic Mycobacterium smegmatis mc2155 strain, which is susceptible to the aminoglycoside antibiotic kanamycin, and M.smegmatis mc2155 containing the empty vector pVV16, which is kanamycin-resistant. Bacteria were incubated in a culture medium containing 50% of deuterium oxide (D2O) and either 1 or 2 times the minimal inhibitory concentration (MIC50) of kanamycin. Lipids were then analyzed using the MBT lipid Xtract matrix combined with routine MALDI mass spectrometry in the positive ion mode to evaluate the changes in the lipid profile. Using this approach, we were able to distinguish susceptible from resistant bacteria in less than 5h, a process that would take 72 h using the conventional broth microdilution method. We therefore propose a solution for the rapid determination of drug susceptibility profiles using a phenotypic assay combining D2O stable isotope labelling and lipid analysis by routine MALDI mass spectrometry.

Ribosomal A site binding pattern differs between Arm methyltransferases from clinical pathogens and a natural producer of aminoglycosides

The extensive use of aminoglycosides to treat bacterial infections has led to significant resistance, posing a global health threat. Recent clinical reports highlight high levels of aminoglycoside resistance due to Arm/Kam methyltransferases, which methylate specific nucleotides in 16S rRNA, preventing antibiotic binding to the ribosome. This study compared the ribosomal A site binding patterns of Arm methyltransferases from clinical pathogens (ArmA, RmtB, RmtC, and RmtD) with those of the Sgm methyltransferase from a natural aminoglycoside producer. We introduced single mutations near the G1405 nucleotide in helix 44 of 16S rRNA to assess their impact on the methylation ability of Arm methyltransferases in E. coli cells with homogeneous mutant ribosomes. We evaluated how these mutations affected bacterial viability in cells with mixed and homogeneous ribosome populations and determined the minimal inhibitory concentration of kanamycin to assess their impact on Arm enzyme activity. Notably, Sgm methyltransferase exhibited a distinct methylation pattern compared to Arm methyltransferases from clinical strains. Structural comparisons of Sgm, RmtB, and RmtC revealed different spatial orientations of key amino acids involved in ribosomal binding, highlighting evolutionary differences. This research enhances understanding of Arm methyltransferases and lays the groundwork for designing inhibitors to combat this potent form of antibiotic resistance.

Establishment of genetic transformation system in Lilium pumilum and functional analysis of LpNAC6 on abiotic stress

Lilium pumilum is widely distributed in northeast Asia. It exhibits strong resistance and possesses high ornamental value. However, it currently lacks an efficient and stable transformation system. Therefore, we aimed to establish an effective genetic transformation system using the Agrobacterium-mediated method for L. pumilum, enabling gene transfer into the plant for gene function research and genetic engineering breeding. Our genetic transformation system achieved a transformation efficiency of 7.25 % under specific conditions: a kanamycin (Kana) concentration of 120 mg/L, 3 days of pre-cultivation, an A. tumefaciens concentration of 0.7 OD600, an acetosyringone (AS) concentration of 20 mg/L, and a 15-minute infection period. We investigated the function of the LpNAC6 from L. pumilum by observing phenotypic and physiological changes under stresses induced by salt, alkali, and drought. Furthermore, overexpression of LpNAC6 resulted in enhanced stress tolerance as evidenced by increased levels of SOD, POD, CAT enzymes, improved photosynthetic indices, and elevated chlorophyll contents; as well as reduced levels of MDA and reactive oxygen species (ROS). These findings demonstrate that we have successfully established a transgenic transformation method for L. pumilum while also providing essential information for cultivating stress-tolerant Lilium species and advancing our understanding of the functions of LpNAC6 in plants.

Chemiluminescence detection of kanamycin by DNA aptamer regulating peroxidase-like activity of Co3O4 nanoparticles.

Kanamycin (KAN) is widely used as a growth hormone analog and an antibacterial agent. However, abuse of this substance has resulted in the accumulation of excessive residue levels in foods of animal origin, which presents a significant risk to human health. A chemiluminescent aptasensor was constructed for the rapid quantitative detection of KAN by combining the properties of Co3O4 nanoparticles (Co3O4 NPs) nanozyme activity and DNA aptamer with high specificity. The DNA aptamer/Co3O4 NPs nanozyme regulated the chemiluminescence signal by exploiting the chemiluminescent properties of luminol oxidation by H2O2. Specific binding of KAN to the aptamer led to the formation of a steric hindrance block in the solution, which inhibited the activity of nanozyme and reduced signal intensity. The degree of signal reduction is related to the concentration of KAN. Under optimal conditions, there was good linearity between KAN concentration and chemiluminescence signal intensity in the range of 0.5-8.0 μΜ, with a detection limit of 0.26 μΜ. The detection system performed well in the presence of competing antibiotics and was virtually unaffected. The method was also suitable for the detection of KAN in milk samples with sample recoveries of 97.8%-99.1%. The chemiluminescence sensor has the advantages of low cost, specificity, and sensitivity, and does not require an external light source or modification of the nucleic acid aptamer which makes it a promising candidate for applications in the field of food detection.

Planar Disk μ-Aptasensors by Monolayer Assembly in a Dissolving Microdroplet.

Electrochemical aptamer-based sensors provide a highly modular platform for real-time monitoring of small molecules. Their ability to selectively recognize target molecules in complex environments like biological fluids makes them an attractive technology for the analysis of micro- and nanoscale systems. The signal-to-noise of the measurement depends on the electroactive surface (i.e., how many aptamers one can place), which has previously precluded miniaturization of aptamer-based sensors to planar disk ultramicroelectrodes (r ∼ 5-10 μm). Here, we employ a concentration enrichment strategy based on the active dissolution of an aqueous, aptamer-containing microdroplet on an ultramicroelectrode submerged in an organic continuous phase (1,2-dichloroethane). We show consistent voltammetric signal increase as a function of droplet lifetime, indicating the successful immobalization of the thiol-terminated aminoglycoside aptamers to the electrode surface. We observe a diagnostic methylene blue peak and 10-fold increase in current magnitude as compared to bare microelectrodes. We report robust sensor behavior with a linear dynamic range extending from milli- to micromolar concentrations of kanamycin in buffer. This research offers a successful method for optimized electrochemical aptamer-based sensor fabrication and miniaturization on ultramicroelectrodes without the need for electrode surface area enhancement.

Genomic and Transcriptomic Analyses Reveal Multiple Strategies for Vibrio parahaemolyticus to Tolerate Sub-Lethal Concentrations of Three Antibiotics.

Vibrio parahaemolyticus can cause acute gastroenteritis, wound infections, and septicemia in humans. The overuse of antibiotics in aquaculture may lead to a high incidence of the multidrug-resistant (MDR) pathogen. Nevertheless, the genome evolution of V. parahaemolyticus in aquatic animals and the mechanism of its antibiotic tolerance remain to be further deciphered. Here, we investigated the molecular basis of the antibiotic tolerance of V. parahaemolyticus isolates (n = 3) originated from shellfish and crustaceans using comparative genomic and transcriptomic analyses. The genome sequences of the V. parahaemolyticus isolates were determined (5.0-5.3 Mb), and they contained 4709-5610 predicted protein-encoding genes, of which 823-1099 genes were of unknown functions. Comparative genomic analyses revealed a number of mobile genetic elements (MGEs, n = 69), antibiotic resistance-related genes (n = 7-9), and heavy metal tolerance-related genes (n = 2-4). The V. parahaemolyticus isolates were resistant to sub-lethal concentrations (sub-LCs) of ampicillin (AMP, 512 μg/mL), kanamycin (KAN, 64 μg/mL), and streptomycin (STR, 16 μg/mL) (p < 0.05). Comparative transcriptomic analyses revealed that there were significantly altered metabolic pathways elicited by the sub-LCs of the antibiotics (p < 0.05), suggesting the existence of multiple strategies for antibiotic tolerance in V. parahaemolyticus. The results of this study enriched the V. parahaemolyticus genome database and should be useful for controlling the MDR pathogen worldwide.

A fluorescent aptasensor for enzyme-free and sensitive detection of kanamycin based on entropy-driven strand displacement reaction

BackgroundKanamycin is an antibiotic that can easily cause adverse side effects if used improperly. Due to the extremely low concentrations of kanamycin in food, quantitative detection of kanamycin becomes a challenge. As one of the DNA self-assembly strategies, entropy-driven strand displacement reaction (EDSDR) does not require enzymes or hairpins to participate in the reaction, which greatly reduces the instability of detection results. Therefore, it is a very beneficial attempt to construct a highly sensitive and specific fluorescence detection method based on EDSDR that can detect kanamycin easily and quickly while ensuring that the results are effective and stable. ResultsWe created an enzyme-free fluorescent aptamer sensor with high specificity and sensitivity for detecting kanamycin in milk by taking advantage of EDSDR and the high specific binding between the target and its aptamer. The specific binding can result in the release of the promoter chain, which then sets off the pre-planned EDSDR cycle. Fluorescent label modification on DNA combined with the fluorescence quenching-recovery mechanism gives the sensor impressive fluorescence response capabilities. The research results showed that within the concentration range of 0.1 nM–50 nM, there was a good relationship between the fluorescence intensity of the solution and the concentration of kanamycin. Specificity experiments and actual sample detection experiments confirmed that the biosensor could achieve highly sensitive and specific detection of trace amounts of kanamycin in food, with a detection limit of 0.053 nM (S/N = 3). SignificanceTo our knowledge, this is the first strategy to combine EDSDR with fluorescence to detect kanamycin in food. Accurate results can be obtained in as little as 90 min with no enzymes or hairpins involved in the reaction. Furthermore, our enzyme-free biosensing method is straightforward, highly sensitive, and extremely specific. It has many possible applications, including monitoring antibiotic residues and food safety.

A novel self-enhanced ECL-RET aptasensor based on the bimetallic MOFs with homogeneous catalytic sites for kanamycin detection

The inappropriate use of antibiotics undoubtedly poses a potential threat to public health, creating an increasing need to develop highly sensitive tests. In this study, we designed a new type of porphyrin metal-organic frameworks (Fe TCPP(Zn) MOFs) with homogeneous catalytic sites. The ferric-based metal ligands of Fe TCPP(Zn) MOFs acted as co-reaction accelerators, which effectively improved the conversion efficiency of H2O2 on the surface of MOFs, then increased the concentration of •OH surrounding porphyrin molecules to achieve self-enhanced electrochemiluminescence (ECL). Based on this, an aptasensor for the specific detection of kanamycin (KAN) in food and environmental water samples was constructed in combination with resonance energy transform (RET), in which Fe TCPP(Zn) MOFs were used as luminescence donor and AuNPs were used as acceptor. Under the best conditions, there was a good linear relationship between the ECL intensity and the logarithm of KAN concentration with a detection limit of 0.28 fM in the range of 1.0 × 10−7–1.0 × 10−13 M, demonstrating satisfactory selectivity and stability. At the same time, the complexity of the detection environment was reduced, which further realized the reliable analysis of KAN in milk, honey and pond water. Overall, this innovative self-enhanced ECL strategy provides a novel approach for constructing efficient ECL systems in MOFs, and also extends the application of MOFs to the analysis and detection of trace antibiotics in food and the environment.

A ratiometric electrochemical aptasensor for sensitive detection of kanamycin in food based on entropy-driven strand displacement reaction

Kanamycin (KAN) has the potential to cause significant harm to human health, so the KAN residue present in food should be subject to strict regulation and control. Therefore, we constructed an enzyme-free ratiometric electrochemical aptasensor based on entropy-driven strand displacement reaction (ESDR) for sensitive detection of KAN in food. In the presence of KAN, it binds specifically to the aptamer, causing KAN-sensitive aptamer-tDNA (A-T) complex dissociation and the release of the tDNA, which triggers ESDR and results in an IFc/IMB maximum. In the absence of KAN, the release of the tDNA is not possible, leading to minimal IFc/IMB value. The aptasensor has a LOD of 74 fg/mL, enabling trace detection of KAN. In addition, the aptasensor demonstrated high specificity for KAN and remarkable reproducibility (RSD: 2.455%), which can be utilised for evaluating KAN concentrations in real samples. Moreover, the recovery rate of KAN in food samples ranged from 93.4% to 105.4%, suggesting that the ratiometric electrochemical aptasensor holds great potential in food safety detection.

A smartphone-based nanoenzyme-modulated aptasensor using an infrared camera for rapid detection of kanamycin

The detection of antibiotics in water is crucial to ensure the safety of drinking water and prevent the spread of antibiotic resistance in the environment. In this study, we present a novel strategy for the selective and sensitive detection of kanamycin (KAN) in water by combining infrared thermography with aptamer detection technology. The aptamers specific to KAN were immobilized on the surface of gold nanoparticles (AuNPs), thereby enhancing the catalytic activity of AuNPs in the 3,3′,5,5′-tetramethylbenzidine (TMB)-hydrogen peroxide system to produce oxidized TMB with photothermal conversion capability. KAN competitively binds to the aptamer and modulates the catalytic capacity of the AuNPs surface, resulting in different photothermal conversion capacities of the final solution. Under near-infrared laser irradiation, the target KAN concentration is converted into a measurable thermal signal. To fabricate a portable sensing setup, we integrated the device with a smartphone. The aptasensor can selectively detect KAN with a limit of detection of 1.55 ng·mL−1 and a limit of quantification of 13.62 ng·mL−1. The detection time of our sensor is real time with a reaction time of 30 min. It demonstrates excellent stability and recoveries ranging from 96.9 % to 106.1 % for practical water samples. This portable aptasensor offers rapid detection, simplicity, and affordability, enabling real-time analysis of antibiotic residues in water.

Dual-mode colorimetric and photothermal aptasensor for detection of kanamycin using flocculent platinum nanoparticles

Chitosan (CS)-stabilized platinum nanoparticles (CS/PtNPs) were employed to develop a novel aptamer-based dual-mode colorimetric and photothermal biosensor for selective detection of kanamycin (KAN). As a peroxidase-like catalyst, the CS/PtNPs showed outstanding catalytic activity for the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). As a stabilizing agent, CS excelled at fixing the KAN binding aptamer on the surface of the CS/PtNPs, amplifying their catalytic activity and enhancing colloidal dispersion and stability. The oxidized TMB (TMBox) functioned as a signal for the colorimetric, photothermal aptasensor because of its observable absorbance of light in the visible and near-infrared (NIR) regions. When light from a NIR laser was absorbed by the TMBox in the reaction solution, heat was generated in inverse proportion to the KAN concentration. The developed colorimetric and photothermal modes of the aptasensor showed a linear detection range of 0.1–50 and 0.5–50 μM, with a limit of detection (LOD) of 0.04 and 0.41 μM, respectively. Moreover, the aptasensor successfully determined KAN concentrations in spiked milk samples, verifying the reliability and reproducibility in practical applications. The dual-mode aptasensor based on CS/PtNPs for KAN detection, utilizing both color change and heat generation signals through a single probe (TMBox), demonstrates rapid response, simplicity in operation, cost-effectiveness, and high sensitivity. In addition, unlike typical immunoassays, this aptamer-based peroxidase-like nanozyme activation and inhibition strategy required no washing process, which was very effective in terms of reducing the time required for an assay and sustaining a high sensitivity.

Efficiency of the alpha-hairpinin SmAMP-X gene promoter from Stellaria media plant depends on selection of transgenic approach.

The antimicrobial activity of the alpha-HAIRPININ ANTIMICROBIAL PEPTIDE X (SmAMP-X gene, GenBank acc. No. HG423454.1) from Stellaria media plant has been shown in vitro. Here, we isolated the SmAMP-X gene promoter and found two genomic sequences for the promoter (designated pro-SmAMP-X and pro-SmAMP-X-Ψ2) with 83% identity in their core and proximal regions. We found that the abilities of these promoters to express the uidA reporter and the nptII selectable marker differ according to the structural organization of T-DNA in the binary vector used for plant transformation. Analysis of Agrobacterium-infiltrated Nicotiana benthamiana leaves, transgenic Arabidopsis thaliana lines, and transgenic Solanum tuberosum plants revealed that both promoters in the pCambia1381Z and pCambia2301 binary vectors generate 42-100% of the ß-glucuronidase (GUS) activity generated by the CaMV35S promoter. According to 5'-RACE (rapid amplification of cDNA ends) analysis, both plant promoters are influenced by the CaMV35S enhancer used to express selectable markers in the T-DNA region of pCambia1381Z and pCambia2301. The exclusion of CaMV35S enhancer from the T-DNA region significantly reduces the efficiency of pro-SmAMP-X-Ψ2 promoter for GUS production. Both promoters in the pCambia2300 vector without CaMV35S enhancer in the T-DNA region weakly express the nptII selectable marker in different tissues of transgenic N. tabacum plants and enable selection of transgenic cells in media with a high concentration of kanamycin. Overall, promoter sequences must be functionally validated in binary vectors lacking CaMV35S enhancer.

Aptamer‐Based Antibiotic Electrochemical Detection Platform Using Portable Plastic Gold Electrode and Multichannel Chip

Comprehensive SummaryThe development of accurate, rapid and practical electrochemical sensing technology for antibiotic detection has an important application prospect in many fields such as food safety, environmental monitoring, medical and health care. In this research, kanamycin specific DNA aptamer and its partially complementary short chain were self‐assembled onto the surface of an integrated portable plastic gold electrode (PGE) by Au—S bond, and a simple kanamycin electrochemical biosensor interface was constructed. At the same time, the epoxy resin channel layer was designed, and the auxiliary instrument was set up independently in the laboratory, which could help to measure and analyze eight groups of samples automatically in turn. The quantitative analysis results showed that in 20 min, the sensor had a good linear relationship between the peak current change of square wave voltammetry and the negative logarithm of kanamycin concentration when kanamycin concentration was in the range of 1—1000 μmol/L, and the detection limit could reach 0.40 μmol/L. In addition, the discrimination could be achieved within 5 min in the real‐time analysis mode. The sensor had a simple construction method, good selectivity and stability, and could be used for rapid or real‐time detection of kanamycin residues in actual water samples, which provided a new direction for the practical detection of kanamycin in environmental water samples.

Phage Antibodies for Kanamycin Detection

Recombinant antibodies specific to kanamycin were obtained using a sheep display library of scFv fragments (Griffin.1) and the possibility of their use for the determination of kanamycin by dot-immunoassay was demonstrated. The minimum detectable concentration of kanamycin is 1 μg/mL (distinguishable label binding other than background). It has been shown that anti-kanamycin phage antibodies are specific for kanamycin and do not interact with other antibiotics (neomycin, tetracycline, ampicillin, gentamicin). Anti-kanamycin phage antibodies are a promising alternative to monoclonal antibodies for use in the determination of kanamycin.

A robust tag-free aptasensor for fluorescent detection of kanamycin assisted by signal intensification potency of rolling circle amplification

Rolling circle amplification (RCA) process as an excellent DNA amplifier strategy possesses the merits of high performance and easy operation. In this research, a sensitive RCA-based fluorescent aptasensor was fabricated for the detection of kanamycin residues in food. The aptasensing approach consisted of two main steps; immobilization of biotinylated kanamycin aptamer on streptavidin magnetic beads (SMB) and separation of free complementary strands (CS) from the SMB-aptamer/kanamycin at the first step. For the second step, RCA procedure was applied as signal magnifier and SYBR Green was added as fluorescent indicator dye. The linear relation between the aptasensor response and kanamycin concentration was obtained from 5 nM to 100 nM with the detection limit of 1.93 nM (S/N = 3). The aptasensor displayed satisfactory selectivity among other antibiotics. The developed aptasensor is reliable for monitoring kanamycin in milk as a common foodstuff.

Optimization of Genetic Transformation on Phytochrome A by Directly Differentiated Buds in Alfalfa

Background: The study showed that phytochrome A (phyA) is involved in alfalfa fall dormancy regulation. To provide the scientific basis for using fall dormancy to predict new varieties’ dormancy class from the molecular level, cultivate alfalfa varieties with cold solid resistance and weak fall dormancy and improve the fall dormancy level of existing excellent types, we could study its function through gene silencing. But the genetic transformation rate is not high, which affects the research progress. Methods: To optimize the genetic transformation system in alfalfa (Medicago sativa L.), a binary plasmid vector pART27-phyA was transferred into alfalfa in Agrobacterium tumefaciens-mediated way. To improve transformation efficiency, we optimized the mediums by screening different Kan (Kanamycin) concentrations, NAA (a-Naphthylacetic acid) concentrations and adding YE (yeast extracts). Result: The results showed that using cotyledon nodes as explants, the proper concentration of Kan antibiotics resistance screening was 100 mg/L, the appropriate concentration of NAA for inducing cotyledon node differentiation was 0.1 mg/L and 0.2 g/L YE was suitable to add on the root induction medium; The expression of phyA in terminal buds and leaves of transformed plants of T1 and T2 generations of phyA in Reindeer was significantly reduced (P less than 0.05), but the expression trend in roots and stems had decreasing trend with no significant changes.

Preparation and antibacterial activity of coronarin E derivatives

Coronarin E is a main diterpene ever isolated from Hedychium yunnanense. With the aim to enlarge its potential application, four butenolide derivatives (compounds 4a, 4b, 5a and 5b) were obtained from coronarin E via synthetic method, and their antibacterial effects were also evaluated. It is noteworthy that compounds 5a and 5b exhibited stronger antibacterial activities against most of the tested bacterial strains than ampicillin and kanamycin, two first- and second-line antimicrobials in clinical. For example, minimum inhibitory concentration (MIC) of 5a, 5b, ampicillin and kanamycin against Acinetobacter baumanii were 2, 1, 8 and 4 μg/mL, respectively, and MIC of the four compounds mentioned above against Klebsiella pneumonia were 1, 0.5, 16 and 4 μg/mL, respectively. The current studies not only enrich the structural diversity of diterpenes derived from Hedychium genus, but also provide potent candidates for the development of antibacterial medicines.

Advances in the Transformation of Cyclamen persicum Mill. Through Direct Regeneration Based on an Optimized Kanamycin Selection Scheme.

Gene transfer technology has great value in ornamental plants toward the generation of varieties with new ornate characteristics. In the previous studies through the transformation of cyclamen, hygromycin was mainly used as a selective marker. However, there have been some drawbacks associated with hygromycin usage as a selecting agent. Therefore, in the current study, the optimization of kanamycin concentration in the regeneration media has been considered. Subsequently, the plant transformation using three different in vitro explants from three Cyclamen persicum cultivars using three Agrobacterium tumefaciens strains has been examined. Accordingly, the optimal kanamycin concentrations for regeneration from root and leaf explants were determined as 10 mg/L and for microtuber explants as 30 mg/L. The successful gene transformation in the antibiotic-resistant shoots were examined by PCR and UV-equipped microscopes. The gfp reporter gene transfer resulted in the highest efficiency of transformation (60%) to date, from the leaf explants of cv. Pure White inoculated with Agrobacterium tumefaciens strain LBA4404. In contrast, the lowest gene transfer efficiency (25%) was observed in root explants of cv. Dark Violet and cv. Neon Pink inoculated with strains GV3101 and AGL-1, respectively. The results of the current project are expandable to the subsequent investigations of Cyclamen persicum transformation.