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Background: The basidiomycete fungus, Ganoderma boninense is the main contributor to oil palm Basal Stem Rot (BSR) in Malaysia and Indonesia. Lanosterol 14α-Demethylase (ERG11) is a key enzyme involved in biosynthesis of ergosterol, which is an important component in the fungal cell membrane. The Azole group fungicides are effective against pathogenic fungi including G. boninense by inhibiting the ERG11 activity. However, the work on molecular characterization of G. boninense ERG11 is still unavailable today., Methods and Results: This study aimed to isolate and characterize the full-length cDNA encoding ERG11 from G. boninense. The G. boninense ERG11 gene expression during interaction with oil palm was also studied. A full-length 1860 bp cDNA encoding ERG11 was successfully isolated from G. boninense. The G. boninense ERG11 shared 91% similarity to ERG11 from other basidiomycete fungi. The protein structure homology modeling of GbERG11 was analyzed using the SWISS-MODEL workspace. Southern blot and genome data analyses showed that there is only a single copy of ERG11 gene in the G. boninense genome. Based on the in-vitro inoculation study, the ERG11 gene expression in G. boninense has shown almost 2-fold upregulation with the presence of oil palm., Conclusion: This study provided molecular information and characterization study on the G. boninense ERG11 and this knowledge could be used to design effective control measures to tackle the BSR disease of oil palm., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The basidiomycete fungus, Ganoderma boninense, has been identified as the main causal agent of oil palm basal stem rot (BSR) disease which has caused significant economic losses to the industry especially in Malaysia and Indonesia. Various efforts have been initiated to understand the disease and this plant pathogen especially at the molecular level. This is the first study of its kind on the development of a polyethylene glycol (PEG)-mediated protoplast transformation system for G. boninense. Based on the minimal inhibitory concentration study, 60 µg/mL and above of hygromycin were effective to completely inhibit G. boninense growth. Approximately 5.145 × 10 7  cells/mL of protoplasts with the viability of 97.24% was successfully obtained from G. boninense mycelium tissue. The PEG-mediated G. boninense protoplast transformation using 1 µg of transformation vector, 25% of PEG solution, 10 min of pre-transformation incubation, and 30 min of post-transformation incubation has improved the transformation rate as compared with the previous reported protocols for other basidiomycete fungi. Optimization of four transformation parameters has improved the transformation efficiency of G. boninense from an average of 2 to 67 putative transformants. The presence of hygromycin phosphotransferase (hpt) and enhanced green fluorescent protein (eGFP) genes in the putative transformants was detected by PCR and verified by gene sequence analysis. Southern hybridization result further confirmed the integration of hpt gene in G. boninense transformants, and the green fluorescent signal was detected in the G. boninense transformants under the microscopic analysis. The establishment of this transformation system will accelerate the gene function studies of G. boninense especially those genes that may contribute to the pathogenesis of this fungus in oil palm., (© 2021. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)

Background: In the UK there is limited coverage of antimicrobial stewardship across postgraduate curricula and evidence that final year medical students have insufficient and inconsistent antimicrobial stewardship teaching. A national undergraduate curriculum for antimicrobial resistance and stewardship is required to standardize an adequate level of understanding for all future doctors., Objectives: To provide a UK national consensus on competencies for antimicrobial resistance and stewardship for undergraduate medical education., Methods: Using the modified Delphi method over two online survey rounds, an expert panel comprising leads for infection teaching from 25 UK medical schools reviewed competency descriptors for antimicrobial resistance and stewardship education., Results: There was a response rate of 100% with all 28 experts who agreed to take part completing both survey rounds. Following the first-round survey, of the initial 55 descriptors, 43 reached consensus (78%). The second-round survey included the 12 descriptors from the first round in which agreement had not been reached, four amended descriptors and 12 new descriptors following qualitative feedback from the panel members. Following the second-round survey, a total of 58 consensus-based competency descriptors within six overarching domains were identified., Conclusions: The consensus-based competency descriptors defined here can be used to inform standards, design curricula, develop assessment tools and direct UK undergraduate medical education., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.)

OXA-48 producers can be difficult to detect in clinical specimens due to phenotypic low-level resistance to carbapenems. Additionally, low infection rates make clinical specimens poor sentinels for the presence of OXA-48 producers within a healthcare institution. We report an outbreak of OXA-48-producing Klebsiella pneumoniae (OXAKp) that was discovered following culture of OXAKp in a urine specimen from a patient with no known risk factors for acquisition. Widespread screening across medical wards in the trust revealed evidence of transmission across several wards. Samples from 60 patients were positive for OXAKp. Five patients had OXAKp clinical infection, four of whom were treated with ceftazidime/avibactam. Variable number tandem repeat analysis of the OXAKp isolates revealed two predominant strain types clustered around two groups of wards. Infection prevention measures included isolation and cohort nursing of infected and colonized patients, restriction of affected ward areas to new admissions, stringent hand hygiene and use of personal protective equipment. Environmental cleaning of patient areas was carried out using chlorine-releasing disinfectants and hydrogen peroxide vapour. Entire wards were decanted to enable effective cleaning of empty ward areas. The outbreak lasted almost five months and is estimated to have cost around £400 000. During the course of the outbreak, there were five reported prescription and administration incidents related to confusion between ceftazidime and ceftazidime/avibactam. No patient harm resulted from these incidents and the implementation of brand name prescribing for ceftazidime/avibactam prevented further incidents., (© 2019 The Authors.)

A 57-year-old man presented with native mitral valve endocarditis caused by Lactococcus garvieae , a known animal pathogen that is increasingly being reported as a cause of human infections. The organism was cultured in four sets of blood cultures and identification was initially made by matrix-assisted laser desorption/ionisation-time of flight mass spectrometry and confirmed by 16S rDNA PCR of the blood culture isolate. He was successfully treated with 6 weeks of both amoxicillin and gentamicin and underwent valve replacement surgery after 4 weeks of antimicrobial treatment. The removed valve was sterile but L. garvieae DNA was detected on the valve using 16S rDNA PCR. The cause of the L. garvieae infection could not be ascertained but flexible sigmoidoscopy demonstrated colonic polyps, which have been linked to infection with this organism., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

We recently reported the bioinspired synthesis of a highly potent nonpeptidic xanthone, 2c (AM-0016), with potent antibacterial activity against MRSA. Herein, we report a thorough structure-activity relationship (SAR) analysis of a series of nonpeptidic amphiphilic xanthone derivatives in an attempt to identify more potent compounds with lower hemolytic activity and greater membrane selectivity. Forty-six amphiphilic xanthone derivatives were analyzed in this study and structurally classified into four groups based on spacer length, cationic moieties, lipophilic chains, and triarm functionalization. We evaluated and explored the effects of the structures on their membrane-targeting properties. The SAR analysis successfully identified 3a with potent MICs (1.56-3.125 μ/mL) and lower hemolytic activity (80.2 μg/mL for 3a versus 19.7 μg/mL for 2c). Compound 3a displayed a membrane selectivity of 25.7-50.4. Thus, 3a with improved HC50 value and promising selectivity could be used as a lead compound for further structural optimization for the treatment of MRSA infection.

This work describes how to tune the amphiphilic conformation of α-mangostin, a natural compound that contains a hydrophobic xanthone scaffold, to improve its antimicrobial activity and selectivity for Gram-positive bacteria. A series of xanthone derivatives was obtained by cationic modification of the free C3 and C6 hydroxyl groups of α-mangostin with amine groups of different pKa values. Modified structures using moieties with high pKa values, such as AM-0016 (3b), exhibited potent antimicrobial properties against Gram-positive bacteria. Compound 3b also killed bacteria rapidly without inducing drug resistance and was nontoxic when applied topically. Biophysical studies and molecular dynamics simulations revealed that 3b targets the bacterial inner membrane, forming an amphiphilic conformation at the hydrophobic-water interface. In contrast, moieties with low pKa values reduced the antimicrobial activity of the parent compound when conjugated to the xanthone scaffold. This strategy provides a new way to improve "hits" for the development of membrane-active antibiotics that target drug-resistant pathogens.