UNASSIGNED: Aminoglycoside-modifying enzymes (AMEs) play an essential role in bacterial resistance to aminoglycoside antimicrobials. With the development of sequencing techniques, more bacterial genomes have been sequenced, which has aided in the discovery of an increasing number of novel resistance mechanisms.
UNASSIGNED: The bacterial species was identified by 16S rRNA gene homology and average nucleotide identity (ANI) analyses. The minimum inhibitory concentration (MIC) of each antimicrobial was determined by the agar dilution method. The protein was expressed with the pCold I vector in E. coli BL21, and enzyme kinetic parameters were examined. The whole-genome sequence of the bacterium was obtained via the Illumina and PacBio sequencing platforms. Reconstruction of the phylogenetic tree, identification of conserved functional residues, and gene context analysis were performed using the corresponding bioinformatic techniques.
UNASSIGNED: A novel aminoglycoside resistance gene, designated aph(3\')-Ie, which confers resistance to ribostamycin, kanamycin, sisomicin and paromomycin, was identified in the chromosome of the animal bacterium Citrobacter gillenii DW61, which exhibited a multidrug resistance phenotype. APH(3\')-Ie showed the highest amino acid identity of 74.90% with the functionally characterized enzyme APH(3\')-Ia. Enzyme kinetics analysis demonstrated that it had phosphorylation activity toward four aminoglycoside substrates, exhibiting the highest affinity (K m, 4.22 ± 0.88 µM) and the highest catalytic efficiency [k cat/K m, (32.27 ± 8.14) × 104] for ribomycin. Similar to the other APH(3\') proteins, APH(3\')-Ie contained all the conserved functional sites of the APH family. The aph(3\')-Ie homologous genes were present in C. gillenii isolates from different sources, including some of clinical significance.
UNASSIGNED: In this work, a novel chromosomal aminoglycoside resistance gene, designated aph(3\')-Ie, conferring resistance to aminoglycoside antimicrobials, was identified in a rabbit isolate C. gillenii DW61. The elucidation of the novel resistance mechanism will aid in the effective treatment of infections caused by pathogens carrying such resistance genes.

One of the resistant mechanisms of EGFR-TKIs is BRAF V600E mutation. Herein, we present the case of a 54-year-old Japanese female who underwent a right middle lobectomy for pathological stage IIB lung adenocarcinoma. One year and nine months after the surgery, she developed multiple intrapulmonary metastases. Osimertinib was administered due to EGFR exon 19 deletion. Although all intrapulmonary metastases had shrunk, the nodule at the superior segment of left lung enlarged after postoperative 4 years. The tumour was resected and BRAF V600E mutation and exon 19 deletion were detected. Three months after treatment with dabrafenib and trametinib instead of osimertinib, the remaining intrapulmonary metastases increased again. The continued growth of the metastatic foci even after EGFR-TKI may indicate an acquired resistance. Thus, a repeat biopsy will aid in confirming the new gene expression. It should have been necessary to administer an additional dose of dabrafenib and trametinib without discontinuing osimertinib.

UNASSIGNED: Despite significant benefits from targeted therapy in patients with driver mutations, inevitable drug resistance usually occurred in non-small cell lung cancer, highlighting the necessity for sequential treatments to prolong overall survival. Unfortunately, durable drug response has not been reported in posterior-line therapy of cases with acquired EML4-ALK fusion after resistance to osimertinib, urging the need of referable decision-making in clinical management.
UNASSIGNED: We present a case of a 71-year-old Chinese female, never smoker, diagnosed with invasive adenocarcinoma in the left inferior lobe of her lung, with metastases in regional lymph nodes. She received erlotinib treatment after the detection of coexistent EGFR L858R/G719S and BRAF V600E via next-generation sequencing of resected tumor tissue. Routine imaging revealed disease progression approximately 14 months after starting erlotinib treatment, followed by the detection of EGFR L858R through non-invasive liquid biopsy. Subsequently, osimertinib was administered, showing clinical activities for nearly 19 months until the emergence of an EML4-ALK fusion. Given the EML4-ALK fusion, a relatively rare resistance mechanism to osimertinib, she received third-line ensartinib treatment. One month later, alleviated tumor lesions plus normal serum marker levels demonstrated the effectiveness of ensartinib in overcoming resistance to osimertinib. Of note, the clinical response to ensartinib persisted for more than 14 months, superior to the previously reported efficacy of aletinib and crizotinib in osimertinib-failure cases. As of the last follow-up in July 2022, the patient showed no signs of recurrence and maintained a good life quality.
UNASSIGNED: We reported a third-line ensartinib therapy in a patient with lung adenocarcinoma who developed an acquired EML4-ALK fusion after sequential treatment with erlotinib and osimertinib. Given the rarity of the EML4-ALK fusion as a resistance mechanism to osimertinib, ensartinib emerges as a promising treatment option for this specific clinical challenge, offering superior efficacy and good safety.

Cytochrome c oxidase (Cox) is a crucial terminal oxidase in the electron transport chain. In this study, we generated 14 Cox gene deletion or overexpression mutants in Fusarium graminearum. Fungicide sensitivity tests revealed that 11 Cox gene deletion mutants displayed resistance to pyraclostrobin, while 10 overexpression mutants showed hypersensitivity. RNA-Seq and RT-qPCR analyses demonstrated the upregulation of FgAox (alternative oxidase in F. graminearum), FgAod2, and FgAod5 (alternative oxidase deficiency in F. graminearum) in ΔFgCox4-2 and ΔFgCox17-75 mutants. In 11 Cox gene deletion mutants, FgAox expression was significantly upregulated, whereas in 10 Cox gene overexpression mutants, it was significantly downregulated. FgAox overexpression mutants exhibit resistance to pyraclostrobin, while FgAox deletion mutants show hypersensitivity to pyraclostrobin. FgAod2 and FgAod5 were identified as transcription factors for FgAox. Our findings reveal that FgCox influences pyraclostrobin sensitivity by regulating FgAox through FgAod2 and FgAod5. Understanding pyraclostrobin resistance mechanisms in F. graminearum could help develop better fungicide rotation and application strategies to manage resistance and guide the creation of new fungicides targeting different pathways.

BACKGROUND: Several patients treated with osimertinib experience progressive disease. The aim was to clarify the mechanisms underlying resistance to osimertinib.
METHODS: ELUCIDATOR: A multi-centre, prospective, observational study involved chemotherapy-naive patients with advanced non-small cell lung cancer receiving osimertinib. Mutations in cancer-associated genes, detected via ultrasensitive next-generation sequencing of circulating tumour deoxyribonucleic acid samples, were collected at baseline and after progressive disease detection. These paired plasma samples were compared.
RESULTS: Of 188 patients enrolled (May 2019-January 2021), 178 (119 females [67 %]) median age 74 years, were included. Patients, n = 95 (53 %) had epidermal growth factor receptor exon 19 deletion mutations. Among 115 patients with progressive disease, circulating tumour deoxyribonucleic acid levels of 85 patients were analysed. MET amplification (n = 4), TP53 mutations (n = 4), PIK3CA mutations (n = 3), BRINP3 mutation (n = 2), BRAF mutation (n = 2), APC mutation (n = 1), RET mutation (n = 1) and epidermal growth factor receptor (EGFR) resistance mutation, and C797S (n = 1) were detected. Patients with baseline TP53 mutations, with MET or EGFR amplification had shorter progression-free (PFS) and overall survival. Patients with PIK3CA mutations tended to shorter PFS.
CONCLUSIONS: MET amplification and PIK3CA mutation mechanisms underly resistance to osimertinib in patients. Patients with coexisting mutations or amplifications at baseline had shorter PFS and overall survival.

Rice blast, caused by Magnaporthe oryzae, is a devastating fungal disease worldwide. Pydiflumetofen (Pyd) is a new succinate dehydrogenase inhibitor (SDHI) that exhibited anti-fungal activity against M. oryzae. However, control of rice blast by Pyd and risk of resistance to Pyd are not well studied in this pathogen. The baseline sensitivity of 109 M. oryzae strains to Pyd was determined using mycelial growth rate assay, with EC50 values ranging from 0.291 to 2.1313 μg/mL, and an average EC50 value of 1.1005 ± 0.3727 μg/mL. Totally 28 Pyd-resistant (PydR) mutants with 15 genotypes of point mutations in succinate dehydrogenase (SDH) complex were obtained, and the resistance level could be divided into three categories of very high resistance (VHR), high resistance (HR) and moderate resistance (MR) with the resistance factors (RFs) of >1000, 105.74-986.13 and 81.92-99.48, respectively. Molecular docking revealed that all 15 mutations decreased the binding-force score for the affinity between Pyd and target subunits, which further confirmed that these 15 genotypes of point mutations were responsible for the resistance to Pyd in M. oryzae. There was positive cross resistance between Pyd and other SDHIs, such as fluxapyroxad, penflufen or carboxin, while there was no cross-resistance between Pyd and carbendazim, prochloraz or azoxystrobin in M. oryzae, however, PydR mutants with SdhBP198Q, SdhCL66F or SdhCL66R genotype were still sensitive to the other 3 SDHIs, indicating lack of cross resistance. The results of fitness study revealed that the point mutations in MoSdhB/C/D genes might reduce the hyphae growth and sporulation, but could improve the pathogenicity in M. oryzae. Taken together, the risk of resistance to Pyd might be moderate to high, and it should be used as tank-mixtures with other classes of fungicides to delay resistance development when it is used for the control of rice blast in the field.

Microorganisms, particularly extremophiles, have evolved multiple adaptation mechanisms to address diverse stress conditions during survival in unique environments. Their responses to environmental coercion decide not only survival in severe conditions but are also an essential factor determining bioproduction performance. The design of robust cell factories should take the balance of their growing and bioproduction into account. Thus, mining and redesigning stress-tolerance elements to optimize the performance of cell factories under various extreme conditions is necessary. Here, we reviewed several stress-tolerance elements, including acid-tolerant elements, saline-alkali-resistant elements, thermotolerant elements, antioxidant elements, and so on, providing potential materials for the construction of cell factories and the development of synthetic biology. Strategies for mining and redesigning stress-tolerance elements were also discussed. Moreover, several applications of stress-tolerance elements were provided, and perspectives and discussions for potential strategies for screening stress-tolerance elements were made.

Black rots lead to great economic losses in winter jujube industry. The objective of this research was to delve into the underlying mechanisms of enhanced resistance of winter jujube fruit to black rot by L-Methionine (Met) treatment. The findings revealed that the application of Met significantly curtailed lesion diameter and decay incidence in winter jujube fruit. The peroxidase (POD) activity in the Met-treated jujubes was 3.06-fold that in the control jujubes after 4 d of treatment. By day 8, the activities of phenylalanine ammonia-lyase (PAL), chitinase (CHI) and β-1,3-glucanase (GLU) in the Met-treated jujubes had surged to their zenith, being 1.39, 1.22, and 1.52 times in the control group, respectively. At the end of storage, the flavonoid and total phenol content remained 1.58 and 1.06 times than that of the control group. Based on metabolomics and transcriptomics analysis, Met treatment upregulated 6 key differentially expressed metabolites (DEMs) (succinic acid, trans-ferulic acid, salicylic acid, delphinium pigments, (S)-abscisic acid, and hesperidin-7-neohesperidin), 12 key differentially expressed genes (DEGs) (PAL, CYP73A, COMT, 4CL, CAD, POD, UGT72E, ANS, CHS, IAA, TCH4 and PR1), which were involved in phenylpropanoid biosynthesis pathway, flavonoid biosynthesis pathway and plant hormone signal transduction pathway. Further analysis revealed that the most of the enzymes, DEMs and DEGs in this study were associated with both antioxidant and disease resistance. Consequently, Met treatment enhanced disease resistance of winter jujube fruit by elevating antioxidant capacity and triggering defense response. This study might provide theoretical support for utilizing Met in the management and prevention of post-harvest black rot in winter jujube.

Anaplastic lymphoma kinase (ALK) inhibitors are the recommended treatment of ALK-rearranged non-small cell lung cancer but are prone to eventual drug resistance. Herein we report a 45-year-old Asian woman diagnosed with EML4-ALK rearranged lung adenocarcinoma. Small cell lung cancer-like phenotypic transformation occurred when resistance to crizotinib treatment. Next-generation sequencing was performed and detected an ALK rearrangement co-existent with a TP53 gene mutation in the small cell specimens. The patient had a good response to alectinib with a progression-free survival >7 months. After disease progression, newly emerged ALK p.G1269A and p.L1196 M gene mutations co-existent with ALK rearrangement were detected. The patient had a good initial response to ceritinib treatment, which last for >12 months. After ceritinib failure, however, more complicated mutations within the ALK kinase domain (p.G1269A, p.L1196 M, newly emerged p.D1203 N, and p.L1122V) were detected. Ultimately, due to terminal rapid progression and resistance to lorlatinib, the overall survival was nearly 3 years. Our case showed that next-generation ALK-tyrosine kinase inhibitors (TKIs) may be an appropriate choice after transformation to small cell lung cancer and failure to one ALK-TKI. Sequential biopsies and gene mutation monitoring are important to arrange the sequence of different generation ALK-TKIs. Appropriate sequential therapies may yield a prolonged response with a satisfactory quality of life in patients with advanced ALK-rearranged non-small cell lung cancer.

The treatment options for multiple myeloma (MM) have undergone significant transformation with the advent of immunotherapy. Novel therapies that focus on tumor antigens now drive advances in MM research. Bispecific antibodies (bsAbs) leverage revolutionary advances in bioengineering techniques and embody the second generation of antibody-based tumor therapy. Recent studies on bsAbs in relapsed/refractory MM cases have revealed remarkable efficacy and acceptable safety profiles. The approval of elranatamab and teclistamab represents the next step in the development of bsAbs for the treatment of MM. This review article addresses the antigen targeting, efficacy, safety, and strategies in the application of bsAbs against treatment-resistant MM, with a focus on clinical trials and real-world data.