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Background: Entomopathogenic nematodes (EPN) are used as a biological control agent for different insect pests in agriculture. The genera Heterorhabditis and Steinernema are the most used commercially. For an EPN species to be used as a biological controller, it is necessary to know its ecological aspects, including reproductive potential, movement capacity, and mean lethal concentration (LC50). These aspects were evaluated in three EPN strains isolated in Galleria mellonella larvae collected in the Lambayeque-Peru region, to determine if they are promising as biological controllers. The strains of EPN studied are Heterorhabditis sp. (PC9 strain), H. bacteriophora Poinar (PM10 strain), and Steinernema diaprepesi Nguyen y Duncan (SV19 strain). Results: Heterorhabditis sp. (PC9 strain) and H. bacteriophora (PM10 strain) had high production of infective juveniles (IJs): 217.750 and 186.800, respectively, while S. diaprepesi (SV19 strain) only reached 84.150 IJs. The movement capacity of Heterorhabditis sp. (PC9 strain) and H. bacteriophora (PM10 strain) reached a depth of 15 cm to parasitize G. mellonella larvae, while S. diaprepesi (SV19 strain) only reached 10 cm. In decreasing order, the LC50 value of S. diaprepesi (SV19 strain), Heterorhabditis sp. (PC9 strain) and H. bacteriophora (PM10 strain) were: 24.03, 13.74, and 8.19 IJs/ml, respectively. Conclusions: Heterorhabditis sp. PC9 and H. bacteriophora PM10 are promising a biological control agent because they present great production of IJs, great displacement capacity, and high pathogenicity against G. mellonella. Additionally, both strains present a mixed search strategy or seeker-hunter (seeker-browser). [ABSTRACT FROM AUTHOR]

The formamidase (FMD) enzyme plays an important role in fungal thriving by releasing a secondary nitrogen source as a product of its activity. In Paracoccidioides species, previous studies have demonstrated the upregulation of this enzyme in a wide range of starvation and infective-like conditions. However, Paracoccidioides lutzii formamidase has not yet been defined as a virulence factor. Here, by employing in vivo infections using an fmd-silenced strain in Galleria mellonella larvae model, we demonstrate the influence of formamidase in P. lutzii's immune stimulation and pathogenicity. The formamidase silencing resulted in improper arrangement of the nodules, poor melanogenesis and decreased fungal burden. Thus, we suggest that formamidase may be a piece composing the process of molecular recognition by Galleria immune cells. Furthermore, formamidase silencing doubled the observed survival rate of the larvae, demonstrating its importance in fungal virulence in vivo. Therefore, our findings indicate that formamidase contributes to Galleria's immune incitement and establishes the role of this enzyme as a P. lutzii virulence factor. Author summary: The study of fungal neglected pathogens is of significant importance for the elucidation of the mechanisms underlying the diseases they cause. The Paracoccidioides lutzii fungus is a pathogen endemic to Latin America, which causes disease in vulnerable portions of society. To cause the disease, the fungal cells must overcome the immune system and obtain nutrients that are typically withdrawn by the host. In this regard, different molecules are crucial for the establishment of infection. The formamidase enzyme plays a role in the survival of the fungus P. lutzii. Our study, presented below, demonstrates that formamidase silencing affects the immune response of G. mellonella larvae to the fungus, resulting in impairment of nodule formation, diminished melanin production, and a reduction in fungal burden. Furthermore, silencing formamidase expression in P. lutzii doubles the survival rate of larvae infected by the fungus, showing its importance for these yeast cells to infect this animals. [ABSTRACT FROM AUTHOR]

Nowadays, particularly metallic, and polymeric nanoparticles (NPs) are widely produced and used in many fields. Due to the increase in both their usage and diversity, their release and accumulation in the environment are also accelerating. Therefore, their interactions with cells, especially immune cells, and their health risks are not fully understood. The impacts of metallic alumina (Al) NPs and polystyrene (PS) NPs obtained after the polymerization of carcinogenic styrene on living organisms have not yet been elucidated. Galleria mellonella larvae can biodegrade plastics. While biodegradation and solving the waste problem have attracted much attention, the interactions of this distinctive property of G. mellonella larvae in the immune system and ecosystem are not yet completely understood. Al and PS NPs were applied to G. mellonella separately. Al NPs were purchased and PS NPs were prepared from PS by single-emulsion technique and characterized. Then LC50 values of these NPs on G. mellonella were determined. The interactions of these NPs with encapsulation, melanization, and phenoloxidase activity, which express innate immune responses in G. mellonella larvae, were revealed. NP exposure resulted in suppression of the immune response, probably because it affects the functions of hemocytes such as enzymatic activation, hemocyte division, and populations. In this context, our data suggest that Al and PS NPs induce toxic impacts and negatively alter the physiological status of G. mellonella. It is also shown that G. mellonella has the potential to be an impactful alternative model for biosafety and nanotoxicology studies. [ABSTRACT FROM AUTHOR]

There is abundant evidence that parasitoids manipulate their hosts by envenomation to support the development and survival of their progeny before oviposition. However, the specific mechanism underlying host nutritional manipulation remains largely unclear. To gain a more comprehensive insight into the effects induced by the gregarious ectoparasitoid Iseropus kuwanae (Hymenoptera: Ichneumonidae) on the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae) larvae, we sequenced the transcriptome of both non‐envenomed and envenomed G. mellonella larvae, specifically targeting genes related to lipid metabolism. The present study revealed that 202 differentially expressed genes (DEGs) were identified and 9 DEGs were involved in lipid metabolism. The expression levels of these 9 DEGs relied on envenomation and the duration post‐envenomation. Further, envenomation by I. kuwanae induced an increase in triglyceride (TG) level in the hemolymph of G. mellonella larvae. Furthermore, silencing GmPLA2 in G. mellonella larvae 24 h post‐envenomation significantly decreased the content of 4 unsaturated fatty acids and TG levels in the hemolymph. The content of linoleic acid and α‐linoleic acid were significantly decreased and the content of oleic acid was significantly increased by exogenous supplement of arachidonic acid. Meanwhile, the reduction in host lipid levels impairs the growth and development of wasp offspring. The present study provides valuable knowledge about the molecular mechanism of the nutritional interaction between parasitoids and their hosts and sheds light on the coevolution between parasitoids and host insects. [ABSTRACT FROM AUTHOR]

Introduction: Developing antibiotic adjuvants is an effective strategy to combat antimicrobial resistance (AMR). The envelope of Gram-negative bacteria (GNB) is a barrier to prevent the entry of antibiotics, making it an attractive target for novel antibiotic and adjuvant development. Methods and Results: In this study, we identified Caspofungin acetate (CAS) as an antibiotic adjuvant against GNB in the repurposing screen of 3,158 FDA-approved drugs. Checkerboard assays suggested that CAS could enhance the antimicrobial activity of rifampin or colistin against various GNB strains in vitro, Moreover, Galleria mellonella larvae infection model also indicated that CAS significantly potentiated the efficacy of rifampin against multidrug-resistant Escherichia coli 72 strain in vivo. Most importantly, resistance development assay showed that CAS was less susceptible to accelerating the resistance development of drug-sensitive strain E. coli MG1655. Functional studies and RNA-seq analysis confirmed that the mechanisms by which CAS enhanced the antimicrobial activities of antibiotics were involved in permeabilizing the bacterial cell envelope, disrupting proton motive force and inhibiting bacterial biofilm formation. Additionally, it has been found that PgaC is the CAS target and enzymatic assay has confirmed the inhibition activity. Discussion: Our results illustrate the feasibility of CAS as an antibiotic adjuvant against GNB, which is an alternative strategy of anti-infection. [ABSTRACT FROM AUTHOR]

Natural products received much attention as an environmentally beneficial solution for pest management. Therefore, the extracts of invasive silverleaf nightshade (Solanum elaeagnifolium Cav.) weeds using their berries parts (seeds, peels and mucilage) supported by bioassay-guided fractionation were tested against both the greater wax moth (Galleria mellonella) and Erwinia carotovora pv. carotovora causes of the blackleg of potatoes. The seeds and peels of S. elaeagnifolium were successively extracted by maceration using dichloromethane (DCM), ethyl acetate (EtOAc), and ethanol (EtOH), respectively. While, its mucilage was extracted using EtOAc. The successive EtOH extract of the plant seeds had promising inhibition efficacy and the best minimal inhibition concentration (MIC) of 50 µg/ml against E. Carotovora amongst other extracts (DCM and EtOAc of the plant berries parts). Depending on dose response activity, EtOH extract had G. mellonella larval mortality and pupal duration rates (LC50; 198.30 and LC95; 1294.73 µg/ml), respectively. Additionally, this EtOH extract of seeds was fractionated using preparative TLC to three characteristic bands. The insecticidal and bacterial activities of these isolated bands (SEA, SEB, and SEC) were evaluated at a dose of 100 µg/ml, causing mortality by 48.48, 62.63 and 92.93% (G. mellonella larvae) and inhibition by 15.22, 0.00 and 31.66 mm (E. carotovora), respectively. Moreover, the separated major three bands were tentatively identified using LC-ESI-MS analysis revealing the presence of two phenolic acids; chlorogenic acid (SEA) and dicaffeoyl quinic acid (SEB) in addition to one steroidal saponin (SEC) annotated as borassoside E or yamoscin. Finally, the plant seeds' successive EtOH extract as well as its active constituents, exhibited potential broad-spectrum activity and the ability to participate in future pest management initiatives. A field study is also recommended to validate its bio-efficacy against selected pests and to develop its formulations. [ABSTRACT FROM AUTHOR]

The greater wax moth, Galleria mellonella (Lepidoptera, Pyralidae), is a major bee pest that inflicts considerable harm on beehives, leading to economic losses. It also serves as a valuable resource insect and a model organism. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein 9 (Cas9) system plays a crucial role in improving economic insect breeding and developing efficient agricultural pest management systems in Lepidoptera. However, the CRISPR/Cas9 protocols have not been developed for G. mellonella. Here, the Gmebony knockout (KO) strain was established using the CRISPR/Cas9 genome editing system. We obtained Gmebony KO strain in the G4 generation, which took approximately 10 months. When compared with wild‐type, the head, notum, and the terminal abdominal surface of 1st to 4th instar larvae in the KO strain changed from yellow to brown, and these regions of the KO strain gradually transformed into a black color from the 5th instar larvae, and the body color of the adult moth in the KO strain changed to black. The developmental period of the early larval and the following larval instars extended. The embryonic hatchability of the Gmebony KO strain was significantly decreased. The pupal body weight of the Gmebony KO strain was not affected. The feasibility of the CRISPR/Cas9 methodology was validated by single‐target editing of Gmebony. Our findings provide the first evidence that the ebony gene can serve as a pigmentation reference gene for genetic modifications of G. mellonella. Meanwhile, it can be utilized in the development of genome editing control strategies and for gene function analyses in G. mellonella. [ABSTRACT FROM AUTHOR]

More than two million people worldwide are affected by life-threatening, invasive fungal infections annually. Candida species are the most common cause of nosocomial, invasive fungal infections and are associated with mortality rates above 40%. Despite the increasing incidence of drug-resistance, the development of novel antifungal formulations has been limited. Here we investigate the antifungal mode of action and therapeutic potential of positively charged, synthetic peptide mimics to combat Candida albicans infections. Our data indicates that these synthetic polymers cause endoplasmic reticulum stress and affect protein glycosylation, a mode of action distinct from currently approved antifungal drugs. The most promising polymer composition damaged the mannan layer of the cell wall, with additional membrane-disrupting activity. The synergistic combination of the polymer with caspofungin prevented infection of human epithelial cells in vitro, improved fungal clearance by human macrophages, and significantly increased host survival in a Galleria mellonella model of systemic candidiasis. Additionally, prolonged exposure of C. albicans to the synergistic combination of polymer and caspofungin did not lead to the evolution of tolerant strains in vitro. Together, this work highlights the enormous potential of these synthetic peptide mimics to be used as novel antifungal formulations as well as adjunctive antifungal therapy. Fungal infections are severely underestimated as a cause of mortality, and alternative drugs are urgently needed. Here, Schaefer et al. show that a synthetic polymer mimicking defensins shows different, but synergistic activity with known antifungals. [ABSTRACT FROM AUTHOR]

The greater wax moth, Galleria mellonella L., poses a substantial threat to apiculture, adversely impacting wax quality and potentially acting as a disease vector. There is an urgent need to develop innovative and effective control strategies to address the challenges posed by this pest and ensure the sustainability of the apiculture industry. Spiro‐derivative compounds represent a novel class of environmentally safe compounds with high insecticidal properties. For example, they have demonstrated high efficacy against sap‐sucking insects such as aphids and whiteflies. However, their effect on chewing insects has not yet been well explored. In this study, we hypothesized that 4‐amino‐1‐azaspiro[4.5]dec‐3‐en‐2‐one (4A1AD), a spiro‐derivative compound, would exhibit efficacy against G. mellonella larvae. To test this hypothesis, we conducted dipping and feeding bioassays, incorporating varying concentrations of 4A1AD on fourth instar G. mellonella larvae, and recorded mortality, biochemical parameters including total soluble protein content and enzyme activities, and anatomical abnormalities resulting from treatment. Results revealed a significant increase in larval mortality with increased concentrations and treatment durations across both bioassays. Additionally, a significant decrease in protein content and an increase in phenol‐oxidase activity were observed with alterations in α and β‐esterase activities. Scanning electron microscope findings revealed abnormalities in larval cuticle, spiracular openings and legs. These findings demonstrated the efficacy of 4A1AD, indicating a potential alternative to conventional insecticides in promoting sustainable apiculture practices. Moreover, they provide valuable contributions to the development of novel strategies for effective pest management in apicultural settings. [ABSTRACT FROM AUTHOR]

We synthesised a sequence of structurally related copper(II) complexes of Schiff base ligands, 2-[(2-benzylamino-ethylimino)-methyl]-phenol [L1(H)], 2-[(2-benzylamino-ethylimino)-methyl]-4-methyl-phenol [L2(H)], and 2-[(2-benzylamino-ethylimino)-methyl]-4-bromo-phenol [L3(H)]. The complexes were characterized by ATR, UV-vis, EPR, ESI-MS, single crystal XRD, and elemental analyses. Based on the crystal structure, the ligand was coordinated to the copper(II) centre in a tridentate mode through phenolate(oxygen), imine nitrogen and amine nitrogen in an NNO fashion and the azide moiety served as an auxiliary ligand. Furthermore, we have investigated the antimicrobial activities of copper(II) complexes against clinically relevant fungal strains, including Candida albicans, Candida glabrata, and Candida tropicalis, as well as bacteria such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), representing Gram-negative and Gram-positive pathogenic strains. Comparing the activity of complex 2 (128–512 μg mL−1) to complex 3 (64–128 μg mL−1), the latter demonstrated more potent effectiveness against all of the tested fungal strains. The activity of the complexes against MRSA reveals the inhibitory concentrations of 1024 μg mL−1 for 1, 128 μg mL−1 for 2, and 256 μg mL−1 for 3. It is worth mentioning that, at their minimum inhibitory concentrations (MICs), the complexes are not toxic to Galleria mellonella. Furthermore, the spot and broth microdilution assay results were in good agreement with the actual metabolic viability of bacterial and fungal strains, in which the complexes were active while having no effect on the metabolite resazurin. Additionally, in silico studies have been employed to elucidate both non-bonding interactions and the mode of action across protein sequences of experimentally studied microbes. The performance of complexes closely mirrored the reactivity order determined in in vitro studies. The impeding properties of complexes can be due to the dysfunctioning of virulent genes and signalling proteins and also affect the activities of transferase and transcriptase proteins. Overall, the complexes are promising candidates for antimicrobial drug development. We anticipate utilising these molecules for clinical purposes. [ABSTRACT FROM AUTHOR]

Infections caused by Staphylococcus aureus pose a significant global public problem. Therefore, new antibiotics and therapeutic strategies are needed to combat this pathogen. This investigation delves into the effects of iclaprim, a newly discovered inhibitor of folic acid synthesis, on S. aureus virulence. The phenotypic and genotypic effects of iclaprim were thoroughly examined in relation to virulence factors, biofilm formation, and dispersal, as well as partial virulence-encoding genes associated with exoproteins, adherence, and regulation in S. aureus MW2, N315, and ATCC 25923. Then, the in vivo effectiveness of iclaprim on S. aureus pathogenicity was explored by a Galleria mellonella larvae infection model. The use of iclaprim at sub-inhibitory concentrations (sub-MICs) resulted in a reduction of α-hemolysin (Hla) production and a differential effect on the activity of coagulase in S. aureus strains. The results of biofilm formation and eradication assay showed that iclaprim was highly effective in depolymerizing the mature biofilm of S. aureus strains at concentrations of 1 MIC or greater, however, inhibited the biofilm-forming ability of only strains N315 and ATCC 25923 at sub-MICs. Interestingly, treatment of strains with sub-MICs of iclaprim resulted in significant stimulation or suppression of most virulence-encoding genes expression. Iclaprim did not affect the production of δ-hemolysin or staphylococcal protein A (SpA), nor did it impact the total activity of proteases, nucleases, and lipases. In vivo testing showed that sub-MICs of iclaprim significantly improves infected larvae survival. The present study offered valuable insights towards a better understating of the influence of iclaprim on different strains of S. aureus. The findings suggest that iclaprim may have potential as an anti-virulence and antibiofilm agent, thus potentially mitigating the pathogenicity of S. aureus and improving clinical outcomes associated with infections caused by this pathogen. Key points: • Iclaprim effectively inhibits α-hemolysin production and biofilm formation in a strain-dependent manner and was an excellent depolymerizing agent of mature biofilm • Iclaprim affected the mRNA expression of virulence-encoding genes associated with exoproteins, adherence, and regulation • In vivo study in G. mellonella larvae challenged with S. aureus exhibited that iclaprim improves larvae survival [ABSTRACT FROM AUTHOR]

Candida tropicalis is regarded as an opportunistic pathogen, causing diseases ranging from superficial infections to life-threatening disseminated infections. The ability of this yeast to form biofilms and develop resistance to antifungals represents a significant therapeutic challenge. Herein, the effect of geraniol (GER), alone and combined with fluconazole (FLZ), was evaluated in the planktonic and sessile cells of azole-resistant C. tropicalis. GER showed a time-dependent fungicidal effect on the planktonic cells, impairing the cell membrane integrity. Additionally, GER inhibited the rhodamine 6G efflux, and the molecular docking analyzes supported the binding affinity of GER to the C. tropicalis Cdr1 protein. GER exhibited a synergism with FLZ against the planktonic and sessile cells, inhibiting the adhesion of the yeast cells and the viability of the 48-h biofilms formed on abiotic surfaces. C. tropicalis biofilms treated with GER, alone or combined with FLZ, displayed morphological and ultrastructural alterations, including a decrease in the stacking layers and the presence of wilted cells. Moreover, neither GER alone nor combined with FLZ caused toxicity, and both treatments prolonged the survival of the Galleria mellonella larvae infected with azole-resistant C. tropicalis. These findings indicate that the combination of GER and FLZ may be a promising strategy to control azole-resistant C. tropicalis infections. [ABSTRACT FROM AUTHOR]

Research into novel anti-Helicobacter pylori agents represents an important approach for the identification of new treatments for chronic gastritis and peptic ulcers, which are associated with a high risk of developing gastric carcinoma. In this respect, two series of azobenzenesulfonamides were designed, synthesized, and tested against a large panel of human and bacterial CAs to evaluate their inhibitory activity. In addition, computational studies of the novel primary benzenesulfonamides (4a–j) were performed to predict the putative binding mode to both HpCAs. Then, the antimicrobial activity versus H. pylori of the two series was also studied. The best-in-class compounds were found to be 4c and 4e among the primary azobenzenesulfonamides and 5c and 5f belonging to the secondary azobenzenesulfonamides series, showing themselves to exert a promising anti-H. pylori activity, with MIC values of 4–8 μg/mL and MBCs between 4 and 16 μg/mL. Moreover, the evaluation of their toxicity on a G. mellonella larva in vivo model indicated a safe profile for 4c,e and 5c,f. The collected results warrant considering these azobenzenesulfonamides as an interesting starting point for the development of a new class of anti-H. pylori agents. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, the use of alternative animal models to vertebrates for the study of infectious processes and antimicrobial drug development has become a major challenge in experimentation. Insects, in particular Galleria mellonella, may represent a good model for preclinical studies, as their response to infections allows for the preliminary selection of molecules with biological activity in a potential sepsis event. However, discordant data are often reported in the literature, and this is often due to the different methods implemented in many laboratories. The aim of this work was therefore to develop a standard protocol for infection with a Gram-positive bacterium, as we consider it important to apply these unified methodologies in order to obtain reproducible data. Our results made it possible to define a correct growth curve of Micrococcus luteus and, in parallel, an infection methodology that would provide consistent and repeatable data. We are therefore confident that this work can be a support for preclinical studies on model insects, as a link between the development of new drugs and its availability for patients. The aim of this work was to develop an experimental protocol for the infection of Galleria mellonella with Gram-positive bacteria. Some physiological characteristics of these insects are comparable to those of vertebrates, therefore allowing the replacement of mammals in the preclinical phases of drug development. G. mellonella Linnaeus 1758 (Lepidoptera: Pyralidae) is accepted as an alternative model for the study of infectious diseases. Since data on infection procedures with different bacterial strains are scarce and sometimes conflicting, also due to different and non-uniform protocols, we developed an experimental protocol that would allow for controlled and repeatable infections, using the Gram-positive bacterium GRAS (Generally Regarded As Safe) Micrococcus luteus. After analyzing the morphology and defining the growth rate of M. luteus, doses of between 101 and 106 CFU/larvae were administered to late-stage larvae. The survival rate of the larvae was monitored up to 7 days and the LD50 determined. The bacterial clearance capacity of the larvae after injection with 103 and 105 CFU/larvae was assessed by hemolymph bacterial load analysis. The results made it possible to define the growth curve of M. luteus correlated with the CFU count; based on the LD50 (103.8 CFU/larvae) calculated on the survival of G. mellonella, infections were carried out to evaluate the immune efficiency of the larvae in bacterial clearance. This protocol, standardized on G. mellonella larvae, could provide a functional tool to study the course of bacterial infections. [ABSTRACT FROM AUTHOR]

Simple Summary: The greater wax moth, Galleria mellonella, is a significant pest in apiculture. This investigation explores the individual and combined effects of the ectoparasite Bracon hebetor (B.h.) and the entomopathogenic nematode Steinernema carpocapsae (S.c.) on G. mellonella larvae. We found that control larvae exhibited higher glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities compared to those treated with B.h., S.c., or the B.h. + S.c. combination. Conversely, malondialdehyde (MDA) levels displayed an opposite trend. Superoxide dismutase (SOD) activity was reduced in the B.h. and S.c. groups but significantly higher in the combined treatment. Cytochrome P450 activity increased in response to parasitism by B. hebetor. The Annexin V-FITC assay revealed decreased cell viability in parasitized groups (B.h. 79.4%, S.c. 77.3%, B.h. + S.c. 70.1%) compared to controls. DNA damage analysis demonstrated significant differences between groups, and SEM observations confirmed severe cuticle abnormalities or malformations in G. mellonella larvae. The greater wax moth, Galleria mellonella, is a significant pest in apiculture and a well-established model organism for immunological and ecotoxicological studies. This investigation explores the individual and combined effects of the ectoparasite Bracon hebetor (B.h.) and the entomopathogenic nematode Steinernema carpocapsae (S.c.) on G. mellonella larvae. We evaluated the activity of oxidative stress enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), malondialdehyde (MDA) levels, cytochrome P450 activity, cell viability using Annexin V-FITC, DNA damage via comet assay, and larval morphology through scanning electron microscopy (SEM). Control larvae exhibited higher GPx and GST activities compared to those treated with B.h., S.c., or the B.h. + S.c. combination. Conversely, MDA levels displayed the opposite trend. SOD activity was reduced in the B.h. and S.c. groups but significantly higher in the combined treatment. Cytochrome P450 activity increased in response to parasitism by B. hebetor. The Annexin V-FITC assay revealed decreased cell viability in parasitized groups (B.h. 79.4%, S.c. 77.3%, B.h. + S.c. 70.1%) compared to controls. DNA damage analysis demonstrated significant differences between groups, and SEM observations confirmed severe cuticle abnormalities or malformations in G. mellonella larvae. These findings highlight the complex interactions between B. hebetor, S. carpocapsae, and their host, G. mellonella. Additionally, they illuminate the intricate physiological responses triggered within the host larvae. [ABSTRACT FROM AUTHOR]

Here, we report the simultaneous isolation of Pseudomonas straminea from blood cultures and from a skin ulcer in an elderly woman who suffered from atopic dermatitis and psoriasis and developed acute cellulitis of both arms requiring hospital treatment. To the best of our knowledge, P. straminea has not been previously reported to cause invasive infections in humans. This case highlights how chronic diseases and older age increase the susceptibility to bacterial infections with environmental bacteria of low virulence. Our study describes the microbiological identification of the blood culture isolate, including morpho-molecular characterization and virulence demonstration in a Galleria mellonella model. [ABSTRACT FROM AUTHOR]

Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. The chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here, we studied the antimicrobial activity of two synthetic PPAP-derivatives, the water-insoluble PPAP23 and the water-soluble sodium salt PPAP53. In vitro, both compounds exhibited good activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar effect was also seen with serum albumin. In silico docking studies with PPAP53 revealed that it binds to the F1 pocket of human serum albumin with a binding energy of −7.5 kcal/mol. In an infection model of septic arthritis, PPAP23 decreased the formation of abscesses and S. aureus load in kidneys; in a mouse skin abscess model, topical treatment with PPAP53 reduced S. aureus counts. Both PPAPs were active against anaerobic Gram-positive gut bacteria such as neurotransmitter-producing Clostridium, Enterococcus or Ruminococcus species. Based on these results, we foresee possible applications in the decolonization of pathogens. [ABSTRACT FROM AUTHOR]

Background The upsurge of antimicrobial resistance demands innovative strategies to fight bacterial infections. With traditional antibiotics becoming less effective, anti-virulence agents or pathoblockers, arise as an alternative approach that seeks to disarm pathogens without affecting their viability, thereby reducing selective pressure for the emergence of resistance mechanisms. Objectives To elucidate the mechanism of action of compound N ′-(thiophen-2-ylmethylene)benzohydrazide (A16B1), a potent synthetic hydrazone inhibitor against the Salmonella PhoP/PhoQ system, essential for virulence. Materials and methods The measurement of the activity of PhoP/PhoQ-dependent and -independent reporter genes was used to evaluate the specificity of A16B1 to the PhoP regulon. Autokinase activity assays with either the native or truncated versions of PhoQ were used to dissect the A16B1 mechanism of action. The effect of A16B1 on Salmonella intramacrophage replication was assessed using the gentamicin protection assay. The checkerboard assay approach was used to analyse potentiation effects of colistin with the hydrazone. The Galleria mellonella infection model was chosen to evaluate A16B1 as an in vivo therapy against Salmonella. Results A16B1 repressed the Salmonella PhoP/PhoQ system activity, specifically targeting PhoQ within the second transmembrane region. A16B1 demonstrates synergy with the antimicrobial peptide colistin, reduces the intramacrophage proliferation of Salmonella without being cytotoxic and enhances the survival of G. mellonella larvae systemically infected with Salmonella. Conclusions A16B1 selectively inhibits the activity of the Salmonella PhoP/PhoQ system through a novel inhibitory mechanism, representing a promising synthetic hydrazone compound with the potential to function as a Salmonella pathoblocker. This offers innovative prospects for combating Salmonella infections while mitigating the risk of antimicrobial resistance emergence. [ABSTRACT FROM AUTHOR]

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal. Diets were assigned to 3 replicate tanks of fish and fed twice daily for 14 days prior to fecal collection. Ingredients, diets, and fecal matter were analyzed in duplicate for proximate, mineral, and amino acid composition. House cricket meals were 67.3% and 69.0% protein (CP) and 16.6% and 17.1% lipid (CL), for house cricket A and B, respectively. Yellow mealworm meal contained 56.5% CP and 27.7% CL, and G. mellonella larvae meal contained 32.5% CP and 54.2% CL. Protein ADCs were 78.9 for G. mellonella larvae meal, 78.0 for yellow mealworm meal, and 76.5 for house cricket A and not different from the MFM protein ADC of 76.6, while house cricket B protein ADC was 65.8 and was significantly lower than the MFM protein ADC (F  = 7.39; df = 4,14; P  = 0.0049). Together, these nutritional values suggest house crickets, and yellow mealworms show promise as alternative protein sources in salmonid feeds, with the potential of G. mellonella as an alternative lipid source. [ABSTRACT FROM AUTHOR]

Prosthetic joint infections (PJIs) can have disastrous consequences for patient health, including removal of the device, and placement of cemented implants is often required during surgery to eradicate PJIs. In translational research, in vivo models are widely used to assess the biocompatibility and antimicrobial efficacy of antimicrobial coatings and compounds. Here, we aim to utilize Galleria mellonella implant infection models to assess the antimicrobial activity of antibiotic-loaded bone cement (ALBC) implants. Therefore, we used commercially available bone cement loaded with either gentamicin alone (PALACOS R+G) or with a combination of gentamicin and vancomycin (COPAL G+V), compared to bone cement without antibiotics (PALACOS R). Firstly, the in vitro antimicrobial activity of ALBC was determined against Staphylococcus aureus. Next, the efficacy of ALBC implants was analyzed in both the G. mellonella hematogenous and early-stage biofilm implant infection model, by monitoring the survival of larvae over time. After 24 h, the number of bacteria on the implant surface and in the tissue was determined. Larvae receiving dual-loaded COPAL G+V implants showed higher survival rates compared to implants loaded with only gentamicin (PALACOS R+G) and the control implants without antibiotics (PALACOS R). In conclusion, G. mellonella larvae infection models with antibiotic-loaded bone cements are an excellent option to study (novel) antimicrobial approaches. [ABSTRACT FROM AUTHOR]

Introduction: Despite the rising concern with fungal resistance, a myriad of molecules has yet to be explored. Geraniol, linalool, and citronellal are monoterpenes with the same molecular formula (C10H18O), however, neither the effect of these compounds on inflammatory axis induced by Candida spp. nor the antibiofilm Structure-Activity Relationship (SAR) have been well-investigated. Herein we analyzed geraniol, linalool and citronellal antifungal activity, cytotoxicity, and distinctive antibiofilm SAR, also the influence of geraniol on Candida spp induced dysregulated inflammatory axis, and in vivo toxicity. Methods: Minimal inhibitory (MIC) and fungicidal (MFC) concentrations against Candida spp were defined, followed by antibiofilm activity (CFU-colony forming unit/mL/g of dry weight). Cytotoxic activity was assessed using human monocytes (THP-1) and oral squamous cell (TR146). Geraniol was selected for further analysis based on antifungal, antibiofilm and cytotoxic results. Geraniol was tested using a dual-chamber co-culture model with TR146 cells infected with C. albicans, and THP-1 cells, used to mimic oral epithelium upon fungal infection. Expression of Candida enzymes (phospholipase-PLB and aspartyl proteases-SAP) and host inflammatory cytokines (interleukins: IL-1ß, IL-6, IL-17, IL-18, IL-10, and Tumor necrosis factor-TNF) were analyzed. Lastly, geraniol in vivo toxicity was assessed using Galleria mellonella. Results: MIC values obtained were 1.25-5 mM/mL for geraniol, 25-100 mM/mL for linalool, and 100-200 mM/mL for citronellal. Geraniol 5 and 50 mM/mL reduced yeast viability during biofilm analysis, only 500 mM/mL of linalool was effective against a 72 h biofilm and no biofilm activity was seen for citronellal. LD50 for TR146 and THP-1 were, respectively: geraniol 5.883 and 8.027 mM/mL; linalool 1.432 and 1.709 mM/mL; and citronellal 0.3006 and 0.1825 mM/mL. Geraniol was able to downregulate expression of fungal enzymes and host proinflammatory cytokines IL-1ß, IL-6, and IL-18. Finally, safety in vivo parameters were observed up to 20 mM/Kg. Discussion: Despite chemical similarities, geraniol presented better antifungal, antibiofilm activity, and lower cytotoxicity when compared to the other monoterpenes. It also showed low in vivo toxicity and capacity to downregulate the expression of fungal enzymes and host pro-inflammatory cytokines. Thus, it can be highlighted as a viable option for oral candidiasis treatment. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "Plastic biodegradation by in vitro environmental microorganisms and in vivo gut microorganisms of insects." The corrigendum addresses errors in the article, including an error in a section title and incorrect information in Tables 2 and 3. The corrected information is provided, and the authors state that these errors do not change the scientific conclusions of the article. The corrigendum also includes a note from the publisher stating that the claims expressed in the article are solely those of the authors and do not necessarily represent the views of the publisher or affiliated organizations. The provided document is a list of references for various scientific studies on the biodegradation of plastic by different insect larvae. The studies explore the ability of larvae from species such as Tribolium confusum, Zophobas atratus, Tenebrio molitor, Galleria mellonella, and others to degrade different types of plastics, including polystyrene and polyethylene. The research examines the effects of plastic diets on the gut microbiota of the larvae and investigates the potential for complete digestion and biodegradation of plastics. The studies provide valuable insights into the role of insects in plastic waste management and offer potential solutions for plastic pollution. [Extracted from the article]

Aeromonas spp. causes the human diseases including diarrhea, gastroenteritis, and bacteremia. Aeromonas spp. can be found in kitchen sponge, one of the reservoirs for food-borne bacterial pathogens. Virulence study of Aeromonas spp. in vivo in animal model is important since the animal model can mimic manifestasions in human infections. Omphisa fuscidentalis was chosen for alternative virulence model, since they are in the same taxonomical order with the well-known infections model, Galleria mellonella. Bacterial isolation and selection of kitchen sponge used Brain Heart Infusion agar and Endo Agar, respectively. Bacterial virulence of KS-1 was injected into Omphisa fuscidentalis larvae. Survival percentage and melanization score of infected larvae were evaluated. Hemolymph of larvae with melanization score of 1 and 4 were stained with Giemsa method to observe the hemocyte changes. Bacterial identification of isolate KS-1 based on 16S rRNA sequence resulted in 96.9% identity to Aeromonas spp. strain VS7. Isolate KS-1 injection to O. fuscidentalis revealed higher bacterial dosage resulting more severe symptoms to the larvae according to survival percentage and melanization score. However, statistical analysis showed evaluation of melanization score could distinguish larvae with 106 and 107 CFU/larva dosage injection, while evaluation of survival percentage could not. Hemocyte of larvae with melanization score 1 had larger and more cytoplasmic vacuolization than the score 4 (healthy larvae). Omphisa fuscidentalis is an alternative of insect model for bacterial infections with survival percentage and melanization score as the evaluation. Cytoplasmic vacuolization of hemocyte can be used as larvae's health indicator in a cellular level. [ABSTRACT FROM AUTHOR]

Background: The resistance of Aspergillus flavus to the azole antifungal drugs is an emerging problem. Mutations in the molecular targets of the azole antifungals ‐ CYP 51 A, B and C ‐ are possible mechanisms of resistance, but data to confirm this hypothesis are scarce. In addition, the behaviour of resistant strains in vitro and in vivo is not yet understood. Objectives: This study had 3 objectives. The first was to compare the sequences of CYP51 A, B and C in resistant and susceptible strains of A. flavus. The second was to look for the existence of a fitness cost associated with resistance. The third was to evaluate the activity of voriconazole and posaconazole on resistant strains in the Galleria mellonella model. Methods: The CYP51 A, B and C sequences of seven resistant strains with those of four susceptible strains are compared. Fitness costs were assessed by growing the strains in RPMI medium and testing their virulence in G. mellonella larvae. In addition, G. mellonella larvae infected with strains of A. flavus were treated with voriconazole and posaconazole. Results: In the CYP51A sequences, we found the A91T, C708T and A1296T nucleotide substitutions only in the resistant strains. The resistant strains showed a fitness cost with reduced in vitro growth and reduced virulence in G. mellonella. In vivo resistance to posaconazole is confirmed in a strain with the highest MIC for this antifungal agent. Conclusions: These results allow to conclude that some substitutions in CYP51 genes, in particular CYP51A, contribute to resistance to azole drugs in A. flavus. The study of the relationship between drug dosage and treatment duration with resistance and the reduction of fitness costs in resistant strains is a major perspective of this study. This work could help to establish recommendations for the treatment of infections with resistant strains of A. flavus. [ABSTRACT FROM AUTHOR]

Aims The purpose of this work was to study extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) in freshwaters, hospital effluents, and wastewaters during two sampling campaigns in 2021. Methods and results Water sampling was performed at 24 stations in the Ourthe watershed in Belgium. A total of 644 ESBL (n  = 642) and AmpC (n  = 2) E. coli strains were isolated. Disk-diffusion assays were performed following the EUCAST's recommendations. All strains were tested for the presence of bla CTX-M-1, bla CTX-M-2, and bla CTX-M-9 gene groups by PCR. Genes belonging to bla CTX-M-1 and bla CTX-M-9 groups were detected, respectively, in 73.6% and 14.9% of the strains. No bla CTX-M-2 group's gene was found. A subset of strains (n  = 40) was selected for whole genome sequencing. Escherichia coli serotype O18: H7 ST 1463 was predominant (n  = 14) in the sequenced strains and showed pathogenicity in the Galleria mellonella larvae model. β-lactamase genes identified were bla CTX-M (n  = 21), with bla CTX-M-15 mostly represented (n  = 15), as well as bla TEM (n  = 11), bla OXA (n  = 7), bla SHV (n  = 9), and carbapenemase (CP) genes were observed in several strains— bla KPC-3 (n  = 19), bla NDM-1 (n  = 1), bla VIM-1 (n  = 2), and bla OXA-244 (n  = 2)—even from freshwaters. Conclusions ESBL-EC are widely distributed in the aquatic environment in Belgium and contain a variety of ESBL and CP genes. [ABSTRACT FROM AUTHOR]

Candidemia is an opportunistic mycosis with high morbidity and mortality rates. Even though Candida albicans is the main causative agent, other Candida species, such as Candida tropicalis, are relevant etiological agents of candidiasis and candidemia. Compared with C. albicans, there is currently limited information about C. tropicalis' biological aspects, including those related to the cell wall and the interaction with the host. Currently, it is known that its cell wall contains O-linked mannans, and the contribution of these structures to cell fitness has previously been addressed using cells subjected to chemical treatments or in mutants where O-linked mannans and other wall components are affected. Here, we generated a C. tropicalis pmt2∆ null mutant, which was affected in the first step of the O-linked mannosylation pathway. The null mutant was viable, contrasting with C. albicans where this gene is essential. The phenotypical characterization showed that O-linked mannans were required for filamentation; proper cell wall integrity and organization; biofilm formation; protein secretion; and adhesion to extracellular matrix components, in particular to fibronectin; and type I and type II collagen. When interacting with human innate immune cells, it was found that this cell wall structure is dispensable for cytokine production, but mutant cells were more phagocytosed by monocyte-derived macrophages. Furthermore, the null mutant cells showed virulence attenuation in Galleria mellonella larvae. Thus, O-linked mannans are minor components of the cell wall that are involved in different aspects of C. tropicalis' biology. [ABSTRACT FROM AUTHOR]

Purpose: Enterobacteriaceae carrying mcr-9, in particularly those also co-containing metallo-β-lactamase (MBL) and TEM type β-lactamase, present potential transmission risks and lack adequate clinical response methods, thereby posing a major threat to global public health. The aim of this study was to assess the antimicrobial efficacy of a combined ceftazidime/avibactam (CZA) and aztreonam (ATM) regimen against carbapenem-resistant Enterobacter cloacae complex (CRECC) co-producing mcr-9, MBL and TEM. Methods: The in vitro antibacterial activity of CZA plus ATM was evaluated using a time-kill curve assay. Furthermore, the in vivo interaction between CZA plus ATM was confirmed using a Galleria mellonella (G. mellonella) infection model. Results: All eight clinical strains of CRECC, co-carrying mcr-9, MBL and TEM, exhibited high resistance to CZA and ATM. In vitro time-kill curve analysis demonstrated that the combination therapy of CZA + ATM exerted significant bactericidal activity against mcr-9, MBL and TEM-co-producing Enterobacter cloacae complex (ECC) isolates with a 100% synergy rate observed in our study. Furthermore, in vivo survival assay using Galleria mellonella larvae infected with CRECC strains co-harboring mcr-9, MBL and TEM revealed that the CZA + ATM combination significantly improved the survival rate compared to the drug-treatment alone and untreated control groups. Conclusion: To our knowledge, this study represents the first report on the in vitro and in vivo antibacterial activity of CZA plus ATM against CRECC isolates co-harboring mcr-9, MBL and TEM. Our findings suggest that the combination regimen of CZA + ATM provides a valuable reference for clinicians to address the increasingly complex antibiotic resistance situation observed in clinical microorganisms. [ABSTRACT FROM AUTHOR]

Vulvovaginal candidiasis (VVC) remains a prevalent fungal disease, characterized by challenges, such as increased fungal resistance, side effects of current treatments, and the rising prevalence of non-albicans Candida spp. naturally more resistant. This study aimed to propose a novel therapeutic approach by investigating the antifungal properties and toxicity of 2-hydroxychalcone (2-HC) and 3′-hydroxychalcone (3′-HC), both alone and in combination with fluconazole (FCZ) and clotrimazole (CTZ). A lipid carrier (LC) was also developed to deliver these molecules. The study evaluated in vitro anti-Candida activity against five Candida species and assessed cytotoxicity in the C33-A cell line. The safety and therapeutic efficacy of in vivo were tested using an alternative animal model, Galleria mellonella. The results showed antifungal activity of 2-HC and 3′-HC, ranging from 7.8 to 31.2 as fungistatic and 15.6 to 125.0 mg/L as fungicide effect, with cell viability above 80% from a concentration of 9.3 mg/L (2-HC). Synergistic and partially synergistic interactions of these chalcones with FCZ and CTZ demonstrated significant improvement in antifungal activity, with MIC values ranging from 0.06 to 62.5 mg/L. Some combinations reduced cytotoxicity, achieving 100% cell viability in many interactions. Additionally, two LCs with suitable properties for intravaginal application were developed. These formulations demonstrated promising therapeutic efficacy and low toxicity in Galleria mellonella assays. These results suggest the potential of this approach in developing new therapies for VVC. [ABSTRACT FROM AUTHOR]

Alternative strategies for controlling Staphylococcus aureus and other pathogens have been continuously investigated, with nisin, a bacteriocin widely used in the food industry as a biopreservative, gaining increasing attention. In addition to its antimicrobial properties, bacteriocins have significant effects on genome functionality even at inhibitory concentrations. This study investigated the impact of subinhibitory concentrations of nisin on S. aureus. Culturing in the presence of 0.625 μmol l−1 nisin, led to the increased relative expression of hla, saeR , and sarA , genes associated with virulence while expression of the sea gene, encoding staphylococcal enterotoxin A (SEA), decreased. In an in vivo experiment, Galleria mellonella larvae inoculated with S. aureus cultured in the presence of nisin exhibited 97% mortality at 72 h post-infection, compared to over 40% of larvae mortality in larvae infected with S. aureus. A comprehensive understanding of the effect of nisin on the transcriptional response of virulence genes and the impact of these changes on the virulence of S. aureus can contribute to assessing the application of this bacteriocin in food and medical contexts. [ABSTRACT FROM AUTHOR]

Simple Summary: Entomopathogenic nematodes and their symbiotic bacteria are widely utilized for biological control. However, whether nematode-derived signals influence the immune response of insects remains unexplored. In this study, we provide comprehensive insight into the interactions among symbiotic bacteria, nematode pheromone ascarosides, and the G. mellonella insect host. Our findings reveal that under the induction of Photorhabdus bacteria, ascarosides enhance the host's immunity response. Specifically, they suppress the intensity of body color change and increase the expression of related-immunity gene expression. Additionally, ascarosides reduce the Photorhabdus cell load and delay G. mellonella larval mortality. These results imply that G. mellonella larvae may employ nematode pheromones to enhance insect immunity in the presence of symbiotic bacteria, thereby enhancing the resistance to invasive bacteria. Insects protect themselves through their immune systems. Entomopathogenic nematodes and their bacterial symbionts are widely used for the biocontrol of economically important pests. Ascarosides are pheromones that regulate nematode behaviors, such as aggregation, avoidance, mating, dispersal, and dauer recovery and formation. However, whether ascarosides influence the immune response of insects remains unexplored. In this study, we co-injected ascarosides and symbiotic Photorhabdus luminescens subsp. kayaii H06 bacteria derived from Heterorhabditis bacteriophora H06 into the last instar larvae of Galleria mellonella. We recorded larval mortality and analyzed the expressions of AMPs, ROS/RNS, and LPSs. Our results revealed a process in which ascarosides, acting as enhancers of the symbiotic bacteria, co-induced G. mellonella immunity by significantly increasing oxidative stress responses and secreting AMPs (gallerimycin, gloverin, and cecropin). This led to a reduction in color intensity and the symbiotic bacteria load, ultimately resulting in delayed host mortality compared to either ascarosides or symbiotic bacteria. These findings demonstrate the cross-kingdom regulation of insects and symbiotic bacteria by nematode pheromones. Furthermore, our results suggest that G. mellonella larvae may employ nematode pheromones secreted by IJs to modulate insect immunity during early infection, particularly in the presence of symbiotic bacteria, for enhancing resistance to invasive bacteria in the hemolymph. [ABSTRACT FROM AUTHOR]

Objectives MRSA is a major cause of hospital-acquired and community-acquired infections. Treatment options for MRSA are limited because of the rapid development of β-lactam resistance. Combining antibiotics offers an affordable, time-saving, viable and efficient approach for developing novel antimicrobial therapies. Both amoxicillin and cefdinir are oral β-lactams with indications for a wide range of bacterial infections and mild side effects. This study aimed to investigate the in vitro and in vivo efficacy of combining these two β-lactams against MRSA strains. Methods Fourteen representative prevalent MRSA strains with diverse sequence types (STs) were tested with a combination of amoxicillin and cefdinir, using chequerboard and time–kill assays. The Galleria mellonella larvae infection model was used to evaluate the in vivo efficacy of this dual combination against the community-acquired MRSA (CA-MRSA) strain USA300 and the hospital-acquired MRSA (HA-MRSA) strain COL. Results The chequerboard assay revealed a synergistic activity of the dual amoxicillin/cefdinir combination against all tested MRSA strains, with fractional inhibitory concentration index (FICI) values below 0.5 and at least a 4-fold reduction in the MICs of both antibiotics. Time–kill assays demonstrated synergistic bactericidal activity of this dual combination against the MRSA strain USA300 and strain COL. Moreover, in vivo studies showed that the administration of amoxicillin/cefdinir combination to G. mellonella larvae infected with MRSA strains significantly improved the survival rate up to 82%, which was comparable to the efficacy of vancomycin. Conclusions In vitro and in vivo studies indicate that the dual combination of amoxicillin/cefdinir demonstrates a synergistic bactericidal efficacy against MRSA strains of various STs. Further research is needed to explore its potential as a treatment option for MRSA infections. [ABSTRACT FROM AUTHOR]

Background The bla B, bla GOB and bla CME genes are thought to confer β-lactam resistance to Elizabethkingia anophelis , based on experiments conducted primarily on Escherichia coli. Objectives To determine the individual contributions of β-lactamase genes to increased MICs in E. anophelis and to assess their impact on the in vivo efficacy of carbapenem therapy. Methods Scarless gene deletion of one or more β-lactamase gene(s) was performed in three clinical E. anophelis isolates. MICs were determined by broth microdilution. Hydrolytic activity and expressions of β-lactamase genes were measured by an enzymatic assay and quantitative RT–PCR, respectively. In vivo efficacy was determined using Galleria mellonella and murine thigh infection models. Results The presence of bla B resulted in >16-fold increases, while bla GOB caused 4–16-fold increases of carbapenem MICs. Hydrolysis of carbapenems was highest in lysates of bla B-positive strains, possibly due to the constitutionally higher expression of bla B. Imipenem was ineffective against bla B-positive isolates in vivo in terms of improvement of the survival of wax moth larvae and reduction of murine bacterial load. The deletion of bla B restored the efficacy of imipenem. The bla B gene was also responsible for a >4-fold increase of ampicillin/sulbactam and piperacillin/tazobactam MICs. The presence of bla CME, but not bla B or bla GOB, increased the MICs of ceftazidime and cefepime by 8–16- and 4–8-fold, respectively. Conclusions The constitutionally and highly expressed bla B gene in E. anophelis was responsible for increased MICs of carbapenems and led to their poor in vivo efficacy. bla CME increased the MICs of ceftazidime and cefepime. [ABSTRACT FROM AUTHOR]

The common cutworm, Spodoptera litura, is a serious insect pest of many vegetables and crops worldwide. Entomopathogenic nematodes (EPN) have been utilized as biological control agents for controlling various insect pests, including the larvae of S. litura. Many indigenous EPN have been recognized to be more effective in specific field applications. Among the 160 soil samples collected in undisturbed areas of western Thailand, three samples tested positive for EPN. Three indigenous EPN were identified as Steinernema siamkayai namely, EPNKU63, EPNKU70 and EPNKU85, based on ITS and D2/D3 expansion region analysis of the 28s rRNA genes. Additionally, genetic analysis of the symbiotic bacteria using recA rRNA sequences confirmed their identity as Xenorhabdus stockiae namely, PEPNKU63, PEPNKU70 and PEPNKU85. To evaluate their initial biocontrol potential against the 6th instar larvae of Galleria mellonella, virulence assays were conducted. The application of 100 infective juveniles (IJs)/insects resulted in the mortality of 80–100% of G. mellonella larvae after 72 h. When symbiotic bacteria were applied at 1 × 106 cells/insect, they exhibited 63–93% mortality against G. mellonella larvae after 120 h. In further laboratory tests, three S. siamkayai isolates achieved 100% mortality of 3rd instar Spodoptera litura larvae within 72 h, with LC50 values ranging from 29 to 30 IJs/insect. In screenhouse experiments, it was revealed that all S. siamkayai isolates displayed substantial virulence, ranging from 62% to 74%, against 3rd instar S. litura larvae within 72 h. This study demonstrates the biocontrol potential of S. siamkayai in controlling S. litura larvae. [ABSTRACT FROM AUTHOR]

The approved anthelmintic salicylanilide drug niclosamide has shown promising anticancer and antimicrobial activities. In this study, new niclosamide derivatives with trifluoromethyl, trifluoromethylsulfanyl, and pentafluorosulfanyl substituents replacing the nitro group of niclosamide were prepared (including the ethanolamine salts of two promising salicylanilides) and tested for their anticancer activities against esophageal adenocarcinoma (EAC) cells. In addition, antifungal activity against a panel of Madurella mycetomatis strains, the most abundant causative agent of the neglected tropical disease eumycetoma, was evaluated. The new compounds revealed higher activities against EAC and fungal cells than the parent compound niclosamide. The ethanolamine salt 3a was the most active compound against EAC cells (IC50 = 0.8–1.0 µM), and its anticancer effects were mediated by the downregulation of anti-apoptotic proteins (BCL2 and MCL1) and by decreasing levels of β-catenin and the phosphorylation of STAT3. The plausibility of binding to the latter factors was confirmed by molecular docking. The compounds 2a and 2b showed high in vitro antifungal activity against M. mycetomatis (IC50 = 0.2–0.3 µM) and were not toxic to Galleria mellonella larvae. Slight improvements in the survival rate of G. mellonella larvae infected with M. mycetomatis were observed. Thus, salicylanilides such as 2a and 3a can become new anticancer and antifungal drugs. [ABSTRACT FROM AUTHOR]

Candida auris is an emerging, multidrug-resistant yeast that causes systemic infections, mainly in hospitalized or immunosuppressed patients. This pathogen has a high mortality and morbidity rate. This study aims to evaluate the antifungal potential of micafungin (MICA) encapsulated in a nanoemulsion (NEM) against four clades of C. auris and other non-C. auris species. The antifungal potential of MICA and NEM was evaluated by determining mature biofilm inhibition (0.78–50 µg/mL). The antifungal activities of MICA and NEM (5.92 mg/Kg) were evaluated using an in vivo model of Galleria mellonella. The results showed that NEM intensified the antibiofilm action of MICA, especially in 48 h mature biofilms. In vivo results displayed a higher effectiveness of NEM against all clades of C. auris tested, inhibiting the fungal load in the hemolymph and tissues of G. mellonella with a difference of 3 log10. In addition, C. auris infection caused granulomas surrounded by hemocytes, mainly at the lower and upper ends. Conversely, C. albicans developed pseudohyphae, biofilms, filaments, and chlamydospores. In conclusion, encapsulation of MICA in a nanoemulsion enhances its antifungal activity against mature biofilms of C. auris. This strategy may be considered a therapeutic approach for the control of infections and the dissemination of this new global health threat. [ABSTRACT FROM AUTHOR]

Background: Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features of both multidrug-resistant and hypervirulent KP. However, clinically used indicators for hypervirulent KP identification, such as hypermucoviscosity, appear to be differentially expressed in convergent KP, potential outbreak clones are difficult to identify. We aimed to fill such knowledge gaps by investigating the temperature dependence of hypermucoviscosity and virulence in a convergent KP strain isolated during a clonal outbreak and belonging to the high-risk sequence type (ST)307. Methods: Hypermucoviscosity, biofilm formation, and mortality rates in Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C and 42°C) and with various phenotypic experiments including electron microscopy. The underlying mechanisms of the phenotypic changes were explored via qPCR analysis to evaluate plasmid copy numbers, and transcriptomics. Results: Our results show a temperature-dependent switch above 37°C towards a hypermucoviscous phenotype, consistent with increased biofilm formation and in vivo mortality, possibly reflecting a bacterial response to fever-like conditions. Furthermore, we observed an increase in plasmid copy number for a hybrid plasmid harboring carbapenemase and rmpA genes. However, transcriptomic analysis revealed no changes in rmpA expression at higher temperatures, suggesting alternative regulatory pathways. Conclusion: This study not only elucidates the impact of elevated temperatures on hypermucoviscosity and virulence in convergent KP but also sheds light on previously unrecognized aspects of its adaptive behavior, underscoring its resilience to changing environments. [ABSTRACT FROM AUTHOR]

Syzigium aromaticum essential oil (EO), eugenol, and β-caryophyllene were evaluated regarding antifungal, antibiofilm, and in vitro toxicity. Additionally, in vivo toxicity of EO was observed. Anti-Candida activity was assessed through broth microdilution assay for all compounds. Time-kill assay (0, 1, 10, 30 min, 1, 2, and 4 h) was used to determine the influence of EO and eugenol on Candida Growth kinetics. Thereafter, both compounds were evaluated regarding their capacity to act on a biofilm formation and on mature biofilm, based on CFU/ml/g of dry weight. Cell Titer Blue Viability Assay was used for in vitro cytotoxicity, using oral epithelial cells (TR146) and human monocytes (THP-1). Lastly, Galleria mellonella model defined the EO in vivo acute toxicity. All compounds, except β-cariofilene (MIC > 8000 μg/ml), presented antifungal activity against Candida strains (MIC 500–1000 μg/ml). The growth kinetics of Candida was affected by the EO (5xMIC 30 min onward; 10xMIC 10 min onward) and eugenol (5xMIC 10 min onward; 10xMIC 1 min onward). Fungal viability was also affected by 5xMIC and 10xMIC of both compounds during biofilm formation and upon mature biofilms. LD50 was defined for TR146 and THP1 cells at, respectively, 59.37 and 79.54 μg/ml for the EO and 55.35 and 84.16 μg/ml for eugenol. No sign of toxicity was seen in vivo up to 10mg/ml (20 x MIC) for the EO. S. aromaticum and eugenol presented antifungal and antibiofilm activity, with action on cell growth kinetics. In vivo acute toxicity showed a safe parameter for the EO up to 10 mg/ml. [ABSTRACT FROM AUTHOR]

Background: Addressing microbial resistance urgently calls for alternative treatment options. This study investigates the impact of a bimetallic formulation containing colistin, silver, and copper oxide on a pandrug-resistant, highly virulent Pseudomonas aeruginosa (P. aeruginosa) isolate from a cancer patient at the National Cancer Institute, Cairo University, Egypt. Methods: Silver nanoparticles (Ag NPs), copper oxide nanoparticles (CuO NPs), and bimetallic silver-copper oxide nanoparticles (Ag-CuO NPs) were synthesized using gamma rays, combined with colistin (Col), and characterized by various analytical methods. The antimicrobial activity of Col-Ag NPs, Col-CuO NPs, and bimetallic Col-Ag-CuO NPs against P. aeruginosa was evaluated using the agar well diffusion method, and their minimum inhibitory concentration (MIC) was determined using broth microdilution. Virulence factors such as pyocyanin production, swarming motility, and biofilm formation were assessed before and after treatment with bimetallic Col-Ag-CuO NPs. The in vivo efficacy was evaluated using the Galleria mellonella model, and antibacterial mechanism were examined through membrane leakage assay. Results: The optimal synthesis of Ag NPs occurred at a gamma ray dose of 15.0 kGy, with the highest optical density (OD) of 2.4 at 375 nm. Similarly, CuO NPs had an optimal dose of 15.0 kGy, with an OD of 1.5 at 330 nm. Bimetallic Ag-CuO NPs were most potent at 15.0 kGy, yielding an OD of 1.9 at 425 nm. The MIC of colistin was significantly reduced when combined with nanoparticles: 8 µg/mL for colistin alone, 0.046 µg/mL for Col-Ag NPs, and 0.0117 µg/mL for Col-Ag-CuO NPs. Bimetallic Col-Ag-CuO NPs reduced the MIC four-fold compared to Col-Ag NPs. Increasing the sub-inhibitory concentration of bimetallic nanoparticles from 0.29 × 10-2 to 0.58 × 10-2 µg/mL reduced P. aeruginosa swarming by 32–64% and twitching motility by 34–97%. At these concentrations, pyocyanin production decreased by 39–58%, and biofilm formation was inhibited by 33–48%. The nanoparticles were non-toxic to Galleria mellonella, showing 100% survival by day 3, similar to the saline-treated group. Conclusions: The synthesis of bimetallic Ag-CuO NPs conjugated with colistin presents a promising alternative treatment for combating the challenging P. aeruginosa pathogen in hospital settings. Further research is needed to explore and elucidate the mechanisms underlying the inhibitory effects of colistin-bimetallic Ag-CuO NPs on microbial persistence and dissemination. [ABSTRACT FROM AUTHOR]

Aspergillus fumigatus represents a public health problem due to the high mortality rate in immunosuppressed patients and the emergence of antifungal-resistant isolates. Protein acetylation is a crucial post-translational modification that controls gene expression and biological processes. The strategic manipulation of enzymes involved in protein acetylation has emerged as a promising therapeutic approach for addressing fungal infections. Sirtuins, NAD+-dependent lysine deacetylases, regulate protein acetylation and gene expression in eukaryotes. However, their role in the human pathogenic fungus A. fumigatus remains unclear. This study constructs six single knockout strains of A. fumigatus and a strain lacking all predicted sirtuins (SIRTKO). The mutant strains are viable under laboratory conditions, indicating that sirtuins are not essential genes. Phenotypic assays suggest sirtuins' involvement in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. Deletion of sirE attenuates virulence in murine and Galleria mellonella infection models. The absence of SirE alters the acetylation status of proteins, including histones and non-histones, and triggers significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals. Sirtuin's function was studied in A. fumigatus by creating knockout strains. SirE encoding gene deletion reduces virulence, alters protein acetylation and gene expression. Sirtuin inhibitors have potential as therapy for A. fumigatus infections. [ABSTRACT FROM AUTHOR]

Exploration of edible insects as sustainable alternative nutrient-dense sources such as nutraceuticals have attracted more and more global attention recently. However, research on wood borer beetles have largely been overlooked. This study assessed the entomo-chemical properties of Titoceres jaspideus (Cerambycidae) and Passalus punctiger (Passalidae), which are widely consumed in many African countries, including Kenya. The crude protein content of the beetle larvae ranged between 27.5–39.8 mg BSA/g. In comparison with those of cereals, amino acids such as lysine (7.9–9.9 mg/g), methionine (0.48–0.64 mg/g) and threonine (2.31–2.55 mg/g) were considerably high in the larvae. Methyl-5Z,8Z,11Z,14Z-eicosatetraenoate and methyl-9Z-octadecenoate were the predominant polyunsaturated and monounsaturated fatty acids, respectively. High total phenols (>4.4 mg GAE/g), flavonoids (>3.6 mg QE/g) and anti-oxidative activities (>67%) were recorded for both larvae. This implies that increasing the consumption of wood-borer beetle larvae would positively impact the state of the natural environment and reduce the problem of malnutrition in the society. Thus, applying these strategies to develop insect food in a more familiar form can help to make insect-enriched foods more appealing to consumers, facilitating their widespread adoption as a sustainable and nutritious food source. [ABSTRACT FROM AUTHOR]

In the fight against hospital-acquired infections, the challenge posed by methicillin-resistant Staphylococcus aureus (MRSA) necessitates the development of novel treatment methods. This study focused on undermining the virulence of S. aureus, especially by targeting surface proteins crucial for bacterial adherence and evasion of the immune system. A primary aspect of our approach involves inhibiting sortase A (SrtA), a vital enzyme for attaching microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) to the bacterial cell wall, thereby reducing the pathogenicity of S. aureus. Verbascoside, a phenylethanoid glycoside, was found to be an effective SrtA inhibitor in our research. Advanced fluorescence quenching and molecular docking studies revealed a specific interaction between verbascoside and SrtA, pinpointing the critical active sites involved in this interaction. This molecular interaction significantly impedes the SrtA-mediated attachment of MSCRAMMs, resulting in a substantial reduction in bacterial adhesion, invasion, and biofilm formation. The effectiveness of verbascoside has also been demonstrated in vivo, as shown by its considerable protective effects on pneumonia and Galleria mellonella (wax moth) infection models. These findings underscore the potential of verbascoside as a promising component in new antivirulence therapies for S. aureus infections. By targeting crucial virulence factors such as SrtA, agents such as verbascoside constitute a strategic and potent approach for tackling antibiotic resistance worldwide. Key points: • Verbascoside inhibits SrtA, reducing S. aureus adhesion and biofilm formation. • In vivo studies demonstrated the efficacy of verbascoside against S. aureus infections. • Targeting virulence factors such as SrtA offers new avenues against antibiotic resistance. [ABSTRACT FROM AUTHOR]

Neuropeptides are crucial in regulation of a rich variety of developmental, physiological, and behavioral functions throughout the life cycle of insects. Using an integrated approach of multiomics, we identified neuropeptide precursors in the greater wax moth Galleria mellonella, which is a harmful pest of honeybee hives with a worldwide distribution. Here, a total of 63 and 67 neuropeptide precursors were predicted and annotated in the G. mellonella genome and transcriptome, in which 40 neuropeptide precursors were confirmed in the G. mellonella peptidome. Interestingly, we identified 12 neuropeptide precursor genes present in G. mellonella but absent in honeybees, which may be potential novel pesticide target sites. Honeybee hives were contaminated with heavy metals such as lead, enabling its bioaccumulation in G. mellonella bodies through the food chain, we performed transcriptome sequencing to analyze the effects of Pb stress on the mRNA expression level of G. mellonella neuropeptide precursors. After treatment by Pb, the expression of neuropeptide F1 was found to be significantly downregulated, implying that this neuropeptide might be associated with responding to the heavy metal stress in G. mellonella. This study comprehensively identified neuropeptide precursors in G. mellonella, and discussed the effects of heavy metals on insect neuropeptides, with the example of G. mellonella. The results are valuable for future elucidation of how neuropeptides regulate physiological functions in G. mellonella and contribute to our understanding of the insect's environmental plasticity and identify potential new biomarkers to assess heavy metal toxicity in insects. [ABSTRACT FROM AUTHOR]

The bethylid wasp Goniozus omanensis has been identified as a key natural enemy of Batrachedra amydraula Meyrick (Lepidoptera: Batrachedridae), an important pest of date palm. Efficient rearing of natural enemies can be an important part of biological pest control programmes but cultures of G. omanensis are challenging to maintain on B. amydraula. We evaluate two readily available species of Pyralid moths, Corcyra cephalonica and Galleria mellonella, as potential factitious hosts. We find that G. omanensis can develop on the larvae of either species, but the probability of failure is circa 75% overall. Both trialled host species were approximately equally suitable, but failures were typically during the early stages of brood production when presented with C. cephalonica and during the later stages when presented with G. mellonella. This suggests that C. cephalonica larvae may be more difficult to suppress and that G. mellonella larvae may be of lower nutritional value. The average production of adult parasitoids per host provided was approximately 1 and, given the observed female biased sex ratio, the average number of females was around 0.8. We suggest potential routes to improving the efficiency of rearing G. omanensis on these factitious hosts. [ABSTRACT FROM AUTHOR]

Insufficient analysis of carriers and their interaction with biocontrol agents can lead to ineffective formulations. Therefore, it is important to thoroughly study the compatibility and interactions between carriers and biocontrol agents for high-quality biological formulations. The present study aimed to evaluate the effect of four different formulation compositions containing gum katira biogel, vermiculite, and diatomaceous earth on the survival and infectivity of infective juveniles (IJs) of two entomopathogenic nematodes (EPNs) species namely, Steinernema abbasi and Heterorhabditis indica at 25 and 35 °C. The physicochemical analysis of the prepared formulations revealed their slightly acidic nature with pH ranging from 5.65 to 6.10. Rheological studies validated the solid-like behavior of the developed formulations. The highest survival of S. abbasi IJs was observed in the case of gum katira biogel-vermiculite blended composition at both 25 °C (94.2%) and 35 °C (88.4%) after 90 days of storage. Interestingly, gum katira biogel alone sustained maximum survival percentage (63.5%) of H. indica as compared to control (41.5%) after 90 days at 25 °C. The formulation compositions failed to retain alive H. indica IJs at 35 °C even after seven days of storage. Moreover, the gum katira singly or in combination with vermiculite resulted in superior infectivity against Galleria mellonella (4th instar larvae) as compared to the other treatments in case of both the nematode species. The presence of diatomaceous earth in all the compositions irrespective of moisture and EPN species showed a negative impact on the survival and infectivity of IJs after 90 days of storage. Gum katira biogel alone or in combination with vermiculite was favorable to sustaining the survivability and infectivity of test EPN IJs at ambient storage temperatures. These formulants can further be used to develop biocontrol EPN formulations for organic farming and integrated pest management programs. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of biostimulants derived from Streptomyces avermitilis metabolites on entomopathogenic nematodes: Steinernema carpocapsae, Steinernema feltiae, and Heterorhabditis bacteriophora, obtained from the soil of several Miscanthus × giganteus plantations in 2020–2023. The nematodes were isolated, identified, and cultured using live insects (the greater wax moth Galleria mellonella). Three preparations containing biostimulants – Charkor, Stimpo, and Regoplant, were tested for compatibility with entomopathogenic and plant parasitic nematodes. Their effect on nematode survival was evaluated using the Petri dish test. The study showed that the effect of biostimulants on the survival of nematodes depended on the concentration of aversectin contained in the evaluated preparations. Stimpo and Regoplant had an adverse effect on plant parasitic nematodes. The highest G. mellonella mortality was observed at the higher dose of Charkor (0.4%), and the lowest at the lower dose of Regoplant (1.22%). The study showed that the virulence of the nematodes decreased after 48 hours of incubation in Regoplant and Stimpo solutions containing aversectin. The degree of interaction between nematodes depended on the nematode species, trophic preferences, and the concentration of active ingredients in the preparations. This conclusion is crucial for the selection of appropriate types of entomopathogenic nematodes and the application rate of plant parasitic nematodes in the assessment of their short- and long-term spread, persistence, and recycling in field conditions. [ABSTRACT FROM AUTHOR]

G. mellonella is a promising species for use in the biodegradation of plastics. It is easy to breed and has high resistance to diverse climatic conditions, which is particularly valuable when considering its potential application in the decomposition of plastics. Thus, it demonstrated the capacity for biodegradation of the most common types of plastics, such as polyethylene (PE) and polypropylene (PP). However, reports on whether consumed plastics or their decomposition products will adversely affect the structure and functioning of the internal organs are rather poor. The studies aimed to determine whether the consumption of PP by a greater wax moth larvae caused any ultrastructural changes in the organs of the animal's body, evaluate the survival rate of the animals, and describe their reproduction. Thus, this study provided an understanding of histological and ultrastructural changes caused, or not caused, by the PP diet. We investigated three organs – midgut, silk gland, and fat body – under PP consumption by G. mellonella caterpillars (7th instar larvae). The level of reactive oxygen species (ROS) in selected organs, as well as the ability of larvae to survive and undergo metamorphosis were also examined. The animals were divided into four groups: G0-C, G0-S, G0-24, and G0-48. The research used transmission electron microscopy (TEM), confocal microscopy, and flow cytometry. Our study showed that a diet containing PP did not affect internal organs at the ultrastructural level. Cells in the analyzed organs – midgut, silk gland, and fat body – showed no degenerative changes. An increase in the intensity of autophagy and cell vacuolization was noted, but they probably act as a survival pathway. These observations suggest that the final larval stage of the greater wax moth can potentially be applied in PP biodegradation. [ABSTRACT FROM AUTHOR]

Objectives: Eumycetoma is a neglected tropical disease (NTD) characterized by subcutaneous lesions and the formation of grains. Attempts to treat eumycetoma involve a combination of antifungal treatment and surgery, although the outcome is frequently disappointing. Therefore, there is a need to identify novel antifungal drugs to treat eumycetoma. In this respect, Medicines for Malaria Venture (MMV) has assembled libraries of compounds for researchers to use in drug discovery research against NTD. Therefore, we screened two MMVOpen compound libraries to identify novel leads for eumycetoma. Methods: A total of 400 compounds from the COVID Box and the Global Health Priority Box were screened in vitro at 100 µM and 25 µM against the most common causative agents of eumycetoma, namely Madurella mycetomatis and Falciformispora senegalensis, and the resulting IC50 and MIC50 values were obtained. Compounds with an IC50 < 8 µM were identified for possible in vivo efficacy studies using an M. mycetomatis grain model in Galleria mellonella larvae. Results: Out of the 400 compounds, 22 were able to inhibit both M. mycetomatis and F. senegalensis growth at 100 µM and 25 µM, with compounds MMV1593278, MMV020335, and MMV1804559 being selected for in vivo testing. Of these three, only the pyrazolopyrimidine derivative MMV1804559 was able to prolong the survival of M. mycetomatis-infected G. mellonella larvae. Furthermore, the grains in MMV1804559-treated larvae were significantly smaller compared to the PBS-treated group. Conclusion: MMV1804559 shows promising in vitro and in vivo activity against M. mycetomatis. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of the neonicotinoid insecticide Thiacloprid on oxidative stress, genotoxic, and immunotoxic biomarkers in Galleria mellonella. The effects of neonicotinoid insecticide thiacloprid on antioxidant enzyme activities, malondialdehyde (MDA) levels, hemocyte number, micronucleus frequency of greater wax moth (Galleria mellonella) larvae at different doses (5, 10, 15, 20, 25, and 30 µg) and periods (24, 48, 72, and 96 hrs) were explored. Superoxide dismutase (SOD) activity increased significantly at 5, 10, and 15 µg thiacloprid doses compared to the control and negative control in all periods tested, while significantly decreased at 20, 25, and 30 µg doses. Catalase (CAT) activity showed significant increases at 5, 10 and 15 µg thiacloprid doses at 24 and 96h compared to the control and negative control. MDA concentrations showed significant increases in all periods compared to the control and negative control. At 24th, 48th, 72nd and 96th, total hemocyte count (THC) decreased significantly at all doses except 5 µg thiacloprid concentration. During all the tested periods, there was a significant increase in the number of micronuclei, particularly at high doses of thiacloprid (20, 25, and 30 µg) compared to both the control and negative control. Additionally, a positive correlation was observed between MDA and the number of micronuclei, while other markers showed a negative correlation with micronucleus (MN). These results suggest that high doses of thiacloprid induce significant increases in micronuclei formation and are positively correlated with MDA levels, indicating oxidative damage and genotoxicity caused by thiacloprid exposure in the tested organism. Overall, our findings suggest that the measured parameters can be considered reliable biomarkers to demonstrate oxidative damage from thiacloprid exposure. [ABSTRACT FROM AUTHOR]

Galleria mellonella is a pest of honeybees in many countries because its larvae feed on beeswax. However, G. mellonella larvae can also eat various plastics, including polyethylene, polystyrene, and polypropylene, and therefore, the species is garnering increasing interest as a tool for plastic biodegradation research. This paper presents an improved genome (99.3% completed lepidoptera_odb10 BUSCO; genome mode) for G. mellonella. This 472 Mb genome is in 221 contigs with an N50 of 6.4 Mb and contains 13,604 protein-coding genes. Genes that code for known and putative polyethylene-degrading enzymes and their similarity to proteins found in other Lepidoptera are highlighted. An analysis of secretory proteins more likely to be involved in the plastic catabolic process has also been carried out. [ABSTRACT FROM AUTHOR]