The development of dressing materials mainly protects the wound, prevents infection, and assists in wound healing. Apart from the most common gauze on the market, different dressing materials can accelerate wound healing. Bacterial cellulose (BC) dressings have had many related studies and applications so far, and other natural or artificial compounds that are beneficial to tissue repair may also be added during the manufacturing process. This study compared the wound healing efficacies of BC dry membrane developed by our team, gauze, commercially available “TegadermTM Hydrocolloid Dressing”, and “AQUACEL® EXTRA Hydrofiber Dressing”. This study used rats as experimental animals and injured them by scalding. Moreover, Staphylococcus aureus was used to infect wounds to compare the effects on wound healing. We first used NIH-3T3 cells for an in vitro model to confirm that the BC membrane is not harmful to cells. In the animal experiment, wounds were created by scalding and then treated with different dressing materials and doses of S. aureus. After 10 days of treatment, the wound recovery in the BC membrane and AQUACEL® groups was the most obvious, including angiogenesis in the dermal layer and regeneration of the epidermis layer. Especially without S. aureus infection, inflammatory markers such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression levels were reduced to those of healthy tissue. In conclusion, we confirmed that the BC dry membrane can accelerate wound healing. In the future, it may provide high-efficiency and less expensive options in the dressing market.

Background Azole antifungals are the first-line choice for treating candidiasis within a limited antifungal option. However, azole-resistant Candida species have increased rapidly, causing severe clinical threats, especially multidrug-resistant (MDR) isolates. The emergence of Candida auris has also caused global concerns recently. Methods Herein, we evaluated the antifungal activity of taurine-induced silver ions (Tau-Ag), prepared by the induction from silver-incorporated mesoporous bioactive glass to address this issue. Results Our data demonstrated that minimum inhibitory concentrations (MICs) of Tau-Ag ranged from 0.020 to 0.078 mg/mL in 24h and from 0.039 to 0.156 mg/mL in 48h. No hemolysis and cytotoxicity were observed at the MICs. Furthermore, no in vivo toxicity related to Tau-Ag was observed in a Caenorhabditis elegans model.In the investigation of antifungal mechanisms, we observed that the reactive oxygen species (ROS) level significantly increased when Candida spp. treated with Tau-Ag. Biofilm formation inhibition assays found that Tau-Ag may penetrate the biofilm and eliminate biofilm-forming cells. In the time-kill method, Tau-Ag showed a long-lasting fungistatic effect and superior antifungal effect compared to itraconazole alone. Furthermore, Tau-Ag showed synergistic antifungal effects in combination with itraconazole, effectively restoring its activity. Conclusion Our results confirmed the potential of Tau-Ag and its combination use with itraconazole to serve as a novel antifungal agent to combat the plight of administration on azole-resistant and MDR Candida spp. and C. auris.

Vibrio strains, identified by 16S rDNA, were isolated from the marine environment surrounding Taiwan, revealing diverse bioactive effects, such as iron-chelating and antimicrobial activities. Notably, the hierarchical clustering dendrogram of mass spectrum profiles (MSP) of the Vibrio strains using MALDI-TOF, in contrast to the phylogenetic tree based on 16S rDNA sequencing analysis, exhibited a strong correlation with their observed bioactivities. Within this set, GNPS molecular network analysis by LC-HRMS/MS highlighted that three strains, Vibrio tubiashii DJW05-1, V. japonicas DJW05-8, and V. fortis DJW21-4 shared similar bioactive pseudopeptides in the same cluster. Subsequent chromatographical isolation and purification yield an unprecedented unsaturated diketopiperazine, (Z)-3-(2-methylpropylidene)-2,3-dihydropyrrolo[1,2-a]pyrazine-1,4-dione (1), along with a series of diketopiperazines, and a potential new annotated pseudopeptide 2, as well as three pseudopeptides, including andrimid (10), moiramide B (11), and moiramide C (12), and several alkaloids from V. tubiashii DJW05-1. Further investigation into the combined applications of the major antimicrobial compound and commercial antibiotics revealed that andrimid (10) displayed significant inhibitory effects against Gram-positive Staphylococcus aureus, and Gram-negative Escherichia coli, Salmonella typhimurium, and Acinetobacter baumannii, except for Pseudomonas aeruginosa. Nevertheless, the potential for synergistic and additive effects of andrimid (10) with certain antibiotics remains, presenting valuable prospects for medicinal applications.

The tellurite toxicity in Haemophilus influenzae and H. parainfluenzae remains unclear. To understand the potential of tellurite as a therapeutic option for these bacteria, we investigated the antimicrobial efficacy of AS101, a tellurium compound, against H. influenzae and H. parainfluenzae and the molecular basis of their differences in AS101 susceptibility. Through broth microdilution, we examined the minimum inhibitory concentration (MIC) of AS101 in 51 H. influenzae and 28 H. parainfluenzae isolates. Whole-genome sequencing was performed on the H. influenzae isolates to identify genetic variations associated with AS101 susceptibility. The MICs of AS101 were ≦ 4, 16–32, and ≧ 64 μg/mL in 9 (17.6

Recently, the high proportion of methicillin-resistant Staphylococcus aureus infections worldwide has highlighted the urgent need for novel antibiotics to combat this crisis. The recent progress in computational techniques for use in health and medicine, especially artificial intelligence (AI), has created new and potential approaches to combat antibiotic-resistant bacteria, such as repurposing existing drugs, optimizing current agents, and designing novel compounds. Halicin was previously used as a diabetic medication, acting as a c-Jun N-terminal protein kinase (JNK) inhibitor, and has recently demonstrated unexpected antibacterial activity. Although previous efforts have highlighted halicin’s potential as a promising antibiotic, evidence regarding its effectiveness against clinical strains remains limited, with insufficient proof of its clinical applicability. In this study, we sought to investigate the antibacterial activity of halicin against MRSA clinical strains to validate its clinical applicability, and a C. elegans model infected by MRSA was employed to evaluate the in vivo effect of halicin against MRSA. Our findings revealed the antibacterial activity of halicin against methicillin-resistant S. aureus clinical strains with MICs ranging from 2 to 4 µg/mL. Our study is also the first work to evaluate the in vivo effect of halicin against S. aureus using a C. elegans model, supporting its further development as an antibiotic.

AIM To investigate the resistance mechanisms of new β-lactam-β-lactamase inhibitor (β+βi) combinations in Enterobacterales isolates from Taiwan. BACKGROUND New β+βi combinations, including ceftazidime-avibactam (CAZ-AVI), aztreonam-avibactam (AZT-AVI), and imipenem-relebactam (IMI-REL), are potential treatments for carbapenem-resistant Enterobacterales (CRE). METHODS To explore their resistance mechanisms, 79 β+βi-resistant isolates (63 K. pneumoniae and 16 E. coli) from Taiwan (2012-2015) were analyzed. RESULTS Resistance rates were 45.6% (36/79) for CAZ-AVI, 13.9% (11/79) for AZT-AVI, and 77.2% (61/79) for IMI-REL. Metallo-β-lactamase genes were the main resistance mechanism in 36 CAZ-AVI-resistant isolates, found in 50% of E. coli (8/16) and 19% of K. pneumoniae (12/63). AZT-AVI resistance (11 isolates) was primarily due to ESBL/AmpC combined with outer membrane protein (Omp) loss and pump hyperactivity, seen in 100% of E. coli (3/3) and 62.5% of K. pneumoniae (5/8). IMI-REL resistance (61 isolates) also involved ESBL/AmpC with Omp loss and pump hyperactivity in 58.3% of E. coli (7/12) and 59.2% of K. pneumoniae (29/49). Two isolates carried KPC-34 (271 ins KHSEAKDD, compared to KPC-2), possessing alteration near the 270-loop region, and KPC-17 accompanied by the OmpK35 loss was observed in the CAZ-AVI-resistant K. pneumoniae. Notably, two IMI-REL-resistant isolates were found with only pump hyperactivity, particularly the kpnF gene, indicating that efflux pumps without ESBL/AmpC may contribute to IMI-REL resistance. Overall, our study revealed a significant contribution of pump hyperactivity to the novel β+βi resistance (48/79, 60.8%). CONCLUSION The current work provided new insights into novel β+βi-resistant mechanisms in Enterobacterales from Taiwan, highlighting the need for ongoing monitoring.

Background: The issue of carbapenem-resistant Escherichia coli was aggravated yearly. The previous studies reported the varied but critical epidemiology of carbapenem-resistant E. coli among which the carbapenemase-producing strains were regarded as one of the most notorious issues. AS101, an organic tellurium-containing compound undergoing clin-ical trials, was revealed with antibacterial activities. However, little is known about the anti-bacterial effect of AS101 against carbapenemase-producing E. coli (CPEC).Materials and methods: The minimum inhibitory concentration (MIC) of AS101 against the 15 isolates was examined using a broth microdilution method. The scanning electron microscopy, pharmaceutical manipulations, reactive oxygen species level, and DNA fragmentation assay were carried out to investigate the antibacterial mechanism. The sepsis mouse model was em-ployed to assess the in vivo treatment effect.Results: The blaNDM (33.3%) was revealed as the dominant carbapenemase gene among the 15 CPEC isolates, followed by the blaKPC gene (26.7%). The MICs of AS101 against the 15 isolates ranged from 0.5 to 32 mg/ml, and 99.9% of bacterial eradication was observed at 8 h, 4 h, and 2 h for 1x, 2x, and 4 x MIC, respectively. The mechanistic investigations suggest that AS101 would enter the bacterial cell, and induce ROS generation, leading to DNA fragmentation. The in vivo study exhibited that AS101 possessed a steady treatment effect in a sepsis mouse model, with an up to 83.3% of survival rate.Conclusion: The in vitro activities, mechanisms, and in vivo study of AS101 against CPEC were unveiled. Our finding provided further evidence for the antibiotic development of AS101.Copyright 2023, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Neisseria gonorrhoeae is an obligate human pathogen responsible for gonorrhea, one of the most common sexually transmitted infections. The yearly increased multidrug resistance in GC has led to treatment failure clinically, suggesting an urgent need for novel therapy to combat the global health issue.

Gonorrhea is the second most common sexually transmitted infection, which is primarily localized but can be disseminated systemically. The mechanisms by which a localized infection becomes a disseminated infection are unknown. We used five pairs of Neisseria gonorrhoeae isolates from the cervix/urethra (localized) and the blood (disseminated) of patients with disseminated gonococcal infection to examine the mechanisms that confine gonococci to the genital tract or enable them to disseminate to the blood. Multilocus sequence analysis found that the local and disseminated isolates from the same patients were isogenic. When culturing in vitro, disseminated isolates aggregated significantly less and transmigrated across a polarized epithelial monolayer more efficiently than localized isolates. While localized cervical isolates transmigrated across epithelial monolayers inefficiently, those transmigrated bacteria self-aggregated less and transmigrated more than cervical isolates but comparably to disseminating isolates. The local cervical isolates recruited the host receptors of gonococcal Opa proteins carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) on epithelial cells. However, the transmigrated cervical isolate and the disseminated blood isolates recruit CEACAMs significantly less often. Our results collectively suggest that switching off the expression of CEACAM-binding Opa(s), which reduces self-aggregation, promotes gonococcal dissemination.

OBJECTIVES:Monkeypox has recently been detected outside African countries. This study aimed to report and analyze the first case of monkeypox virus infection in Taiwan.METHODS:The global epidemiological information was collected from the World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC). The data from the first confirmed Taiwanese monkeypox case was obtained from Taiwan Centers for Disease Control. Monkeypox diagnosis and prevention strategies were obtained from WHO guidelines on monkeypox. Phylogenetic tree analysis and sequence alignment and comparison were used to identify the phylogeny and single nucleotide polymorphism (SNP) characterization.RESULTS:Epidemiological data indicated that since 2013, monkeypox has caused outbreaks outside African countries through contact with infected animals and international travels. Recently, two confirmed monkeypox cases were reported in Singapore and South Korea. On June 24, 2022, Taiwan CDC reported the first confirmed case of monkeypox virus infection in a 20-year-old man who returned from Germany, from January to June 2022. This is the third confirmed case of an imported monkeypox infection in Asia. Phylogenetic analysis demonstrated that this imported monkeypox virus belonged to the West African clade and is clustered with the 2022 European outbreak monkeypox isolates. Full-length sequence analysis indicates that this virus contains 51 SNPs, and has five variant SNPs compared with the recent outbreak strains.CONCLUSION:This study suggests that active surveillance, enhancing border control, and the development of vaccines and antiviral drugs are urgently required to prevent and control the burden of monkeypox disease.

Ambient ionization mass spectrometry (AIMS) is both labor and time saving and has been proven to be useful for the rapid delineation of trace organic and biological compounds with minimal sample pretreatment. Herein, an analytical platform of probe sampling combined with a thermal desorption–electrospray ionization/mass spectrometry (TD-ESI/MS) and multivariate statistical analysis was developed to rapidly differentiate bacterial species based on the differences in their lipid profiles. For comparison, protein fingerprinting was also performed with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) to distinguish these bacterial species. Ten bacterial species, including five Gram-negative and five Gram-positive bacteria, were cultured, and the lipids in the colonies were characterized with TD-ESI/MS. As sample pretreatment was unnecessary, the analysis of the lipids in a bacterial colony growing on a Petri dish was completed within 1 min. The TD-ESI/MS results were further performed by principal component analysis (PCA) and hierarchical cluster analysis (HCA) to assist the classification of the bacteria, and a low relative standard deviation (5.2%) of the total ion current was obtained from repeated analyses of the lipids in a single bacterial colony. The PCA and HCA results indicated that different bacterial species were successfully distinguished by the differences in their lipid profiles as validated by the differences in their protein profiles recorded from the MALDI-TOF analysis. In addition, real-time monitoring of the changes in the specific lipids of a colony with growth time was also achieved with probe sampling and TD-ESI/MS. The developed analytical platform is promising as a useful diagnostic tool by which to rapidly distinguish bacterial species in clinical practice.

Background: Imipenem-relebactam is a new beta-lactam and beta-lactamase inhibitor combination to treat carbapenem- resistant gram-negative bacteria infections. However, difference in carbapenem resistant mechanisms existed with geographic variations. Objective: To evaluate the susceptibility of imipenem-relebactam to 660 carbapenem-nonsusceptible Enterobacteriaceae isolates in Taiwan and to identify the in vivo efficacy with a Caenorhabditis elegans model. Methods: 188 carbapenem-nonsusceptible Escherichia coli isolates and 472 carbapenem-nonsusceptible Klebsiella pneumoniae isolates were collected from a national surveillance study in Taiwan. The antimicrobial susceptibility profiles and carbapenemase distributions were determined. An agar dilution method was performed to evaluate the in vitro activities of imipenem monotherapy and imipenem-relebactam combination. Contributions of metallo-carbapenemase to imipenem-relebactam susceptibility was investigated via EDTA treatment. A C. elegans model was used to evaluate the in vivo efficacy of imipenem-relebactam combination. Results: 87.8% and 82.2% susceptibility to imipenem-relebactam was observed for 188 carbapenem-nonsusceptible E. coli and 472 carbapenem-nonsusceptible K. pneumoniae, respectively. However, poor activities of imipenem-relebactam was observed against 23 metallo-carbapenemase producers tested in this study. In the in vivo C. elegans model, imipenem-relebactam significantly rescued nematodes from the infection of a bla(KPC)-producing K. pneumoniae isolate. Conclusion: Our study supports that imipenem- relebactam is a potential therapy against carbapenem-nonsusceptible Enterobacteriaceae, and to our knowledge, this is the first report of evaluation for imipenem-relebactam efficacy against carbapenem-nonsusceptible Enterobacteriaceae in Taiwan. Copyright (C) 2021, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.

The Clinical and Laboratory Standards Institute (CLSI) revised the fluoroquinolone MIC breakpoints for Enterobacterales in 2019, based on pharmacokinetic/pharmacodynamic analyses. However, clinical evidence supporting these breakpoint revisions is limited.

In this study, we investigated the SiO2-CaO-P2O5 mesoporous bioactive glass (MBG) system doped with Ag. The antibacterial capacity of the system was determined by loading and delivering silver nanoparticles (AgNPs) through the porous structure of MBG. According to X-ray diffraction (XRD) and solid-state magic angle spinning nuclear magnetic resonance (solid-state MAS-NMR) result, Ag-doped MBG maintained its parent glassy structure. Further, the solid-state MAS-NMR results indicated that the Ag content did not influence the network connectivity of the glass substrate. On the other hand, transmission electron microscopy (TEM) images indicated that AgNPs (size < 5 nm) were confined in mesoporous channels and homogeneously dispersed in the bioactive glass substrate. Coalescence of the AgNPs occurred with higher Ag content. The in vitro antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) was the same for MBG with Ag compositions in the range of 1-10 mole ratio in bioactive glass (MIC=10 mg/mL).

In 2017 the World Health Organization listed carbapenem-resistant K. pneumoniae as a critical priority for developing a novel antimicrobial agent. Here we report on our investigation of the antibacterial efficacy of silver nanoparticles (AgNPs), confined to a mesostructured material and designated as an Ag/80S bioactive nanocomposite, against carbapenem-resistant K. pneumoniae. Results from a textural analysis indicate a 7.5 nm mesopore size and 307.6 m2/g surface area for Ag/80S. UV-Vis spectrum and transmission electron microscope images of Ag/80S revealed a uniform AgNP size distribution with an approximately 3.5 nm average. ICP-MS analysis demonstrated a significantly higher silver content in TSB (a protein-rich environment) compared to ultrapure water, suggesting a controllable release of Ag/80S and thus designated as the inspired Ag/80S. Minimum inhibitory concentration (MIC) values against 16 K. pneumoniae isolates ranged from 0.25 to 0.5% (2.5 to 5.0 mg/ml). NIH 3T3 fibroblast viability at 0.25% exceeded 80% and at 0.5% just under 70%, suggesting low cytotoxicity. Mechanistic study results indicate that the inspired Ag/80S attached to and deformed bacterial cells and induced a time-dependent accumulation of reactive oxygen species, leading to bacterial death. Further, inspired Ag/80S significantly extended median survival time in a Caenorhabditis elegans animal model infected with carbapenem-resistant K. pneumoniae ATCC BAA-1705. Combined, we found a novel Ag/80S which could prevent aggregation of AgNP and control its release via a specific environment for medical use against carbapenem-resistant K. pneumoniae.

Owing to the over usage of carbapenems, carbapenem resistance has become a vital threat worldwide, and, thus, the World Health Organization announced the carbapenem-resistant Enterobacteriaceae (CRE) as the critical priority for antibiotic development in 2017. In the current situation, combination therapy would be one solution against CRE. Azidothymidine (AZT), a thymidine analog, has demonstrated its synergistically antibacterial activities with other antibiotics. The unexpected antimicrobial activity of the immunomodulator ammonium trichloro(dioxoethylene-o,o’)tellurate (AS101) has been reported against carbapenem-resistant Klebsiella pneumoniae (CRKP). Here, we sought to investigate the synergistic activity between AS101 and AZT against 12 CRKP clinical isolates. According to the gene detection results, the blaOXA-1 (7/12, 58.3%), blaDHA (7/12, 58.3%), and blaKPC (7/12, 58.3%) genes were the most prevalent ESBL, AmpC, and carbapenemase genes, respectively. The checkerboard analysis demonstrated the remarkable synergism between AS101 and AZT, with the observable decrease in the MIC value for two agents and the fractional inhibitory concentration (FIC) index ≤0.5 in all strains. Hence, the combination of AS101 and azidothymidine could be a potential treatment option against CRKP for drug development.

Colistin- and carbapenem-resistant Enterobacteriaceae cases are increasing at alarming rates worldwide. Drug repurposing is receiving greater attention as an alternative approach in light of economic and technical barriers in antibiotics research. The immunomodulation agent ammonium trichloro(dioxoethylene-O,O’-)tellurate (AS101) was repurposed as an antimicrobial agent against colistin- and carbapenem-resistant Klebsiella pneumoniae (CRKP). 134 CRKP isolates were collected between 2012 and 2015 in Taiwan. The in vitro antibacterial activities of AS101 was observed through broth microdilution, time-kill assay, and electron microscopy. Pharmaceutical manipulation and RNA microarray were applied to investigate these antimicrobial mechanisms. Caenorhabditis elegans, a nematode animal model, and the Institute for Cancer Research (ICR) mouse model was employed for the evaluation of in vivo efficacy. The in vitro antibacterial results were found for AS101 against colistin- and CRKP isolates, with minimum inhibitory concentration (MIC) values ranging from <0.5 to 32 μg/mL. ROS-mediated antibacterial activity eliminated 99.9% of bacteria within 2–4 h. AS101 also extended the median survival time in a C. elegans animal model infected with a colistin-resistant CRKP isolate and rescued lethally infected animals in a separate mouse model of mono-bacterial sepsis by eliminating bacterial organ loads. These findings support the use of AS101 as an antimicrobial agent for addressing the colistin and carbapenem resistance crisis.

DC-SIGN, a C-type lectin mainly expressed in dendritic cells (DCs), has been reported to mediate several viral infections. We previously reported that DC-SIGN mediated H5N1 influenza A virus (AIVs) infection, however, the important DC-SIGN interaction with N-glycosylation sites remain unknown. This study aims to identify the optimal DC-SIGN interacting N-glycosylation sites in HA proteins of H5N1-AIVs. Results from NetNGlyc program analyzed the H5 hemagglutinin sequences of isolates during 2004–2020, revealing that seven and two conserved N-glycosylation sites were detected in HA1 and HA2 domain, respectively. A lentivirus pseudotyped A/Vietnam/1203/04 H5N1 envelope (H5N1-PVs) was generated which displayed an abundance of HA5 proteins on the virions via immuno-electron microscope observation. Further, H5N1-PVs or reverse-genetics (H5N1-RG) strains carrying a serial N-glycosylated mutation was generated by site-directed mutagenesis assay. Human recombinant DC-SIGN (rDC-SIGN) coated ELISA showed that H5N1-PVs bound to DC-SIGN, however, mutation on the N27Q, N39Q, and N181Q significantly reduced this binding (p < 0.05). Infectivity and capture assay demonstrated that N27Q and N39Q mutations significantly ameliorated DC-SIGN mediated H5N1 infection. Furthermore, combined mutations (N27Q&N39Q) significantly waned the interaction on either H5N1-PVs or -RG infection in cis and in trans (p < 0.01). This study concludes that N27 and N39 are two essential N-glycosylation contributing to DC-SIGN mediating H5N1 infection.