Key Pathogens Research Articles

Clinical applications of antimicrobial photodynamic therapy in dentistry.

Given the emergence of resistant bacterial strains and novel microorganisms that globally threaten human life, moving toward new treatment modalities for microbial infections has become a priority more than ever. Antimicrobial photodynamic therapy (aPDT) has been introduced as a promising and non-invasive local and adjuvant treatment in several oral infectious diseases. Its efficacy for elimination of bacterial, fungal, and viral infections and key pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Candida albicans, and Enterococcus faecalis have been investigated by many invitro and clinical studies. Researchers have also investigated methods of increasing the efficacy of such treatment modalities by amazing developments in the production of natural, nano based, and targeted photosensitizers. As clinical studies have an important role in paving the way towards evidence-based applications in oral infection treatment by this method, the current review aimed to provide an overall view of potential clinical applications in this field and summarize the data of available randomized controlled clinical studies conducted on the applications of aPDT in dentistry and investigate its future horizons in the dental practice. Four databases including PubMed (Medline), Web of Science, Scopus and Embase were searched up to September 2022 to retrieve related clinical studies. There are several clinical studies reporting aPDT as an effective adjunctive treatment modality capable of reducing pathogenic bacterial loads in periodontal and peri-implant, and persistent endodontic infections. Clinical evidence also reveals a therapeutic potential for aPDT in prevention and reduction of cariogenic organisms and treatment of infections with fungal or viral origins, however, the number of randomized clinical studies in these groups are much less. Altogether, various photosensitizers have been used and it is still not possible to recommend specific irradiation parameters due to heterogenicity among studies. Reaching effective clinical protocols and parameters of this treatment is difficult and requires further high quality randomized controlled trials focusing on specific PS and irradiation parameters that have shown to have clinical efficacy and are able to reduce pathogenic bacterial loads with sufficient follow-up periods.

P. gingivalis-LPS Induces Mitochondrial Dysfunction Mediated by Neuroinflammation through Oxidative Stress.

Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, is associated with neuroinflammation. Periodontal disease increases with age; 70.1% of adults 65 years and older have periodontal problems. However, the P. gingivalis- lipopolysaccharide (LPS)induced mitochondrial dysfunction in neurodegenerative diseases remains elusive. In this study, we investigated the possible role of P. gingivalis-LPS in mitochondrial dysfunction during neurodegeneration. We found that P. gingivalis-LPS treatment activated toll-like receptor (TLR) 4 signaling and upregulated the expression of Alzheimer's disease-related dementia and neuroinflammatory markers. Furthermore, the LPS treatment significantly exacerbated the production of reactive oxygen species and reduced the mitochondrial membrane potential. Our study highlighted the pivotal role of P. gingivalis-LPS in the repression of serum response factor (SRF) and its co-factor p49/STRAP that regulate the actin cytoskeleton. The LPS treatment repressed the genes involved in mitochondrial function and biogenesis. P. gingivalis-LPS negatively altered oxidative phosphorylation and glycolysis and reduced total adenosine triphosphate (ATP) production. Additionally, it specifically altered the mitochondrial functions in complexes I, II, and IV of the mitochondrial electron transport chain. Thus, it is conceivable that P. gingivalis-LPS causes mitochondrial dysfunction through oxidative stress and inflammatory events in neurodegenerative diseases.

THE PHYTOSANITARY STATUS OF SOME FLOWERING PLANTS CULTIVATED IN DIFFERENT GREEN SPACES IN THE MUNICIPALITY OF CRAIOVA

The research was carried out on 23 host plants and the attack of 32 fungal pathogens was identified.
 The identified pathogens were classified by attack incidence value (F%) into main pathogens, secondary pathogens and potential pests.
 The host plants that were attacked by key pathogens were chrysanthemum, snapdragon, marigold, yarrow, yucca and rose. The host plants that were attacked by pathogens from the secondary group were peony, sedge, oxeye, hydrangea, hyacinth, queen of the night, sage and cloves. Attack of potential harmful pathogens has been recorded on gladioli, tulips, snapdragons, chrysanthemums, marigolds, pansies, dahlias, hydrangea, petunia, cock's crest and primroses. The species in which the simultaneous attack of three key pathogens was registered was the rose.

Опыт лечения мукозита при хроническом гнойном среднем отите у детей

Background: the most common clinical subtype of chronic suppurative otitis media (CSOM) in childhood is low-grade catarrhal inflammation affecting the middle ear mucosa (mucositis). The etiology and pathogenesis of mucositis remain unclear. Virtually no data on the course and treatment of this disease in children are available. Aim: to share our experience with mucositis treatment in children with CSOM. Patients and Methods: we performed a retrospective analysis of treatment results in 118 children aged 5–14 years with subtotal and total tympanic membrane perforations and mucositis of the tympanic cavity of various severity without cholesteatoma. Results: no pathognomonic signs were identified in children with mucositis. All children had mild hearing loss. Temporal bone CT revealed signs of temporal bone and ossicular system destruction in 15 children (12.7%). Microbiological diagnostics demonstrated that the key bacterial pathogens were Pseudomonas aeruginosa (n=26, 22%) and Staphylococcus aureus (n=21, 17.8%). In children with mesotympanitis, the secretory stage of mucositis was diagnosed most often (n=79, 67%), as demonstrated by otomicroscopy. Hyperplastic and atrophic stages of mucositis were diagnosed in 31 (26%) and 8 patients, respectively. During CSOM remission, all patients underwent scheduled myringoplasty and tympanoplasty with revision of the tympanic cavity and mastoid. These procedures were performed under microscopic control via an endaural or transcanal approach. 12 weeks after surgery, 108 patients (92%) reported an improvement in hearing. Diastasis in the lower part of the created eardrum was detected in 11 patients (9.3%) only. Conclusion: given the understudied etiology and pathogenesis, conservative treatment is reasonable only during uncomplicated exacerbation of CSOM. The most effective treatment for mucositis of the tympanic mucosa is timely myringoplasty and tympanoplasty. KEYWORDS: chronic suppurative otitis media, mucositis, children, myringoplasty, tympanoplasty, hearing loss. FOR CITATION: Naumov O.G., Karpova E.P., Tulupov D.A. Treatment for mucositis in children with chronic suppurative otitis media. Russian Medical Inquiry. 2023;7(8):543–548 (in Russ.). DOI: 10.32364/2587-6821-2023-7-8-12.

Efficient clearance of periodontitis pathogens by S. gordonii membrane-coated H2O2 self-supplied nanocomposites in a "Jenga" style.

As a key pathogen of periodontitis, P. gingivalis requires support of the initial colonizing bacterium (S. gordonii preferably) to form symbiotic biofilms on gingival tissues with enhanced antibiotic resistance. Here, we report a new strategy to treat periodontitis biofilms with S. gordonii membrane-coated H2O2 self-supplied nanocomposites (ZnO2/Fe3O4@MV NPs) in a "Jenga" style. Integration of our special MV coatings enables selectively enhanced internalization of the cargos in S. gordonii, thus inducing severe damage to the foundational bacterial layer and collapse/clearance of symbiotic biofilms consequently. This strategy allows us to clear the symbiotic biofilms of S. gordonii and P. gingivalis with active hydroxyl radicals (˙OH) derived from ZnO2-Fe3O4@MV NPs in a H2O2 self-supplied, nanocatalyst-assisted manner. This "Jenga-style" treatment provides a cutting-edge proof of concept for the removal of otherwise robust symbiotic biofilms of periodontitis where the critical pathogens are difficult to target and have antibiotic resistance.

Synthesis of fusidane triterpenoid Mannich bases as potential antibacterial and antitumor agents

Mannich bases (8 examples) were synthesized via aminomethylation of fusidane propargyl esters. In vitro antimicrobial screening against key ESKAPE pathogens showed that the fusidic acid based Mannich products exhibit a high antimicrobial effect against Gram-positive bacteria Staphylococcus aureus and the fungus Cryptococcus neoformans. Moreover, the cytotoxic effect of fusidic acid and its analogs, which showed high antibacterial activity, was determined by MTT assay on cancer HepG2, HCT-116, SH-SY5Y, MCF-7, A549 and conditionally normal cells HEK293. A remarkable cytotoxic activity of fusidic acid propargyl ester and its aminomethylene derivatives against cancer and nontumoral HEK293 cells with IC50 values within 4.2–25 µM was found.

1725. National Surveillance of Gram-negative Bacteria in Qatar, the Study for Monitoring of Antimicrobial Resistance Trends (SMART): from 2017 to 2019

Abstract Background Monitoring Antimicrobial Resistance Trends (SMART) is a global study for the surveillance of antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) from different regions around the World including Gulf countries. To evaluate prevalence and trends in AMR in GNB from clinical specimens including microbiological and genomic characteristics as well as examine Antimicrobial Susceptibility Tests (AST) for existing and novel antimicrobials. Methods A prospective study was conducted on clinical specimens from Hamad Medical Corporation, Qatar, between 2017 and 2019 according to the SMART protocol that covers community as well as hospital-associated infections reported to secondary care. Consecutive GNB were included from different sites including lower respiratory and urinary tracts, intrabdominal, and bloodstream infections. Results Over the three years study period, 895 isolates were studied from the specified sites comprising 38 GNB with four key pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. Meropenem resistance was 3.6% for E. coli and 9.3% for K. pneumoniae while imipenem/relebactam resistance was 3% compared to 8% respectively. The overall ceftolozane/tazobactam resistance for E. coli was 9% (25/281) compared to 13% (34/257) for K. pneumoniae while resistance for ceftazidime/avibactam was 2% (3/137) and 4% (5/117) respectively. Genomic characteristics of 70 Enterobacterales including 48 carbapenem-resistant, revealed the prevalence of β-lactamase from all classes dominated by blaCXM-15 while carbapenem resistance revealed a paucity of blaKPC and supremacy of blaOXA-48 like and blaNDM resistance genes (Table 1). Table 1.The frequency of different β-lactamase genes among 48 Carbapenem Resistant Enterobacterales (ERSs) isolates collect from Qatar between 2017 - 2019.*Intra-abdominal infections (IAIs), respiratory tract infections (RTIs), and urinary tract infections (UTIs) Conclusion Surveillance of GNB from Qatar showed the prevalence of key pathogens similar to the rest of the world but demonstrated significant resistance to existing and novel antimicrobials, particularly for K. pneumoniae with different underlying resistance mechanisms. Disclosures All Authors: No reported disclosures.

Multiplex high-resolution melting assay for simultaneous detection of five key bacterial pathogens in urinary tract infections: A pilot study.

The diagnosis of urinary tract infections (UTIs) is usually based on the results of urine culture, but it is time-consuming, labor-intensive and has a low sensitivity. The aim of this study was to develop multiplex high-resolution melting assay (MHRM) for the simultaneous detection of five common bacterial pathogens (Escherichia coli, Klebsiella pneumoniae, Staphylococcus saprophyticus, Enterococcus faecalis, and group B streptococci (GBS)) directly from urine samples. A total of 287 urine specimens were evaluated by HRM assay and the results were compared with the conventional culture method. Five different melt curves generated and differentiated five bacterial pathogens. The detection limit of the MHRM assay was 1.5 × 103 CFU/ml for E. coli and K. pneumoniae and 1.5 × 102 CFU/ml for S. saprophyticus, E. faecalis and GBS. Compared to culture, the specificity of the MHRM assay ranged from 99.3 to 100%, and sensitivity 100% for all test pathogens. The MHRM assay developed in the current study might be functional tool for the diagnosis of UTIs and has the potential for direct detection of the organism in the clinical samples. Additionally, it creates results in less than 5 h, helping clinicians to start treatment with appropriate antimicrobial agents. This method could be a useful supplement to urine culture.

Genomic islands and their role in fitness traits of two key sepsis-causing bacterial pathogens.

To survive and establish a niche for themselves, bacteria constantly evolve. Toward that, they not only insert point mutations and promote illegitimate recombinations within their genomes but also insert pieces of 'foreign' deoxyribonucleic acid, which are commonly referred to as 'genomic islands' (GEIs). The GEIs come in several forms, structures and types, often providing a fitness advantage to the harboring bacterium. In pathogenic bacteria, some GEIs may enhance virulence, thus altering disease burden, morbidity and mortality. Hence, delineating (i) the GEIs framework, (ii) their encoded functions, (iii) the triggers that help them move, (iv) the mechanisms they exploit to move among bacteria and (v) identification of their natural reservoirs will aid in superior tackling of several bacterial diseases, including sepsis. Given the vast array of comparative genomics data, in this short review, we provide an overview of the GEIs, their types and the compositions therein, especially highlighting GEIs harbored by two important pathogens, viz. Acinetobacter baumannii and Klebsiella pneumoniae, which prominently trigger sepsis in low- and middle-income countries. Our efforts help shed some light on the challenges these pathogens pose when equipped with GEIs. We hope that this review will provoke intense research into understanding GEIs, the cues that drive their mobility across bacteria and the ways and means to prevent their transfer, especially across pathogenic bacteria.

Guanylate-binding protein 1 restricts avian coronavirus infectious bronchitis virus-infected HD11 cells

The Infectious Bronchitis Virus (IBV), a coronavirus, is a key avian pathogen that causes acute and highly infectious viral respiratory diseases. IBV is an enveloped, positive-sense RNA virus, and the host factors that restrict infection and replication of the virus remain poorly understood. Guanylate-binding protein 1 (GBP1), an interferon-gamma (IFN-γ)-inducible guanosine triphosphatase (GTPase), is a major player in host immunity and provides defense against viral replication. However, the role of chicken GBP1 (chGBP1) in the IBV-life cycle is not well understood. Therefore, this study aimed to reveal the potential role of IFN-γ-induced chGBP1 in mediating host anti-IBV infection responses. We identified the host restriction factor, chGBP1, in IBV-infected chicken macrophages HD11 cell lines. We showed that chGBP1 was upregulated by treatment with both IFN-γ and IBV in HD11 cells. chGBP1 inhibited IBV replication in a dose-dependent manner and enhanced IFN-γ anti-IBV activity. Importantly, the GTPase domain of chGBP1 played a pivotal role in its anti-IBV activity. Furthermore, chGBP1 interacts with IBV Nucleocapsids protein to degrade IBV-N protein through the autophagy pathway. Taken together, our results demonstrate a critical role of chGBP1 in anti-IBV in macrophages HD11 cells.

The inhibitory effect of gourami fish scale (Osphronemus gouramy) extract-curcumin combination on Porphyromonas gingivalis

Background: Gourami fish scales, often considered as a waste, turned out to be an alternative source for antibacterial components. Its extract contains alkaloid, an antibacterial agent, while also contains hydrogen bonds which have the effect of increasing the interaction with other substances. Curcumin is one of the active ingredients of turmeric, a spice commonly used as an herbal medicine in Indonesia. Curcumin could suppress bacterial proliferation by inhibiting virulence agents. The combination of these substances was expected to help inhibit Porphyromonas gingivalis growth, one of the key pathogens in periodontitis patients. Objective: This study aims to determine the inhibitory effect of the gourami fish scale extract-curcumin combination on the growth of P. gingivalis bacteria. Method: This research is an in vitro experimental analytical laboratory research. The concentrations used are 100%; 50%; 25%; 12.5%; 6.25%; 3.125%; 1.56%; and 0.78%. The inhibition testing on P. gingivalis bacteria cultures was carried out by spectrophotometric methods and colony counts. Results: Gourami fish scale extract-curcumin combination with a concentration of 12.5%; 25%; 50%; and 100% killed colonies of P. gingivalis bacteria resulting in 0 colonies. A concentration of 6.25% inhibits bacterial growth by 92.9%. The statistical test result showed a significant difference (p < 0.05). Conclusion: Gourami fish scale extract-curcumin combination has an inhibitory effect on the growth of P. gingivalis bacteria with MIC value at the concentration of 6.25% and MBC of 12.5%.

Porphyromonas gingivalis infection promotes inflammation via inhibition of the AhR signalling pathway in periodontitis.

Porphyromonas gingivalis (P. gingivalis) is a key pathogen of chronic periodontitis. Aryl hydrocarbon receptor (AhR) is essential in immune homeostasis via modulation of pro-inflammatory cytokines production and indoleamine 2,3-dioxygenase (IDO). In this study, it is demonstrated that P. gingivalis may regulate AhR signalling in periodontitis, which provides a potential target for further immune regulation studies in periodontitis. Experimental periodontitis was induced in C57BL/6 mice by silk ligature and P. gingivalis oral inoculation. The alveolar bone resorption was examined using Micro-CT. Histological structures were observed and related cytokines involved in AhR signalling pathway were analysed. RAW264.7 cells were pretreated with AhR agonist (FICZ) and antagonist (CH223191) and infected with P. gingivalis subsequently. The levels of IDO, AhR and other related cytokines were measured. To demonstrate IDO activity, the concentrations of tryptophan (Trp) and kynurenine (Kyn) were assessed by HPLC. Histological analysis of periodontitis mice showed distinct alveolar bone resorption and inflammatory cell infiltration. The level of AhR and its downstream target factors were significantly decreased in inflamed gingival tissue. Furthermore, RAW 264.7 cells incubated by P. gingivalis exhibited increased pro-inflammatory cytokines production and decreased AhR, CYP1A1, CYP1B1, and IDO expression. Decreased IDO activity was observed as decreased Kyn/Trp ratio in the supernatant. Moreover, FICZ decreased the pro-inflammatory cytokines levels in P. gingivalis infected cells. It is concluded that P. gingivalis may promote inflammatory responses via inhibiting the AhR signalling pathway in periodontitis.

Antagonistic interaction between two key endodontic pathogens Enterococcus faecalis and Fusobacterium nucleatum

ABSTRACT Background Endodontic infections are known to be caused by pathogenic bacteria. Numerous previous studies found that both Fusobacterium nucleatum and Enterococcus faecalis are associated with endodontic infections, with Fusobacterium nucleatum more abundant in primary infection while Enterococcus faecalis more abundant in secondary infection. Little is known about the potential interactions between different endodontic pathogens. Objective This study aims to investigate the potential interaction between F. nucleatum and E. faecalis via phenotypical and genetic approaches. Methods Physical and physiological interactions of F. nucleatum and E. faecalis under both planktonic and biofilm conditions were measured with co-aggregation and competition assays. The mechanisms behind these interactions were revealed with genetic screening and biochemical measurements. Results E. faecalis was found to physically bind to F. nucleatum under both in vitro planktonic and biofilm conditions, and this interaction requires F. nucleatum fap2, a galactose-inhibitable adhesin-encoding gene. Under our experimental conditions, E. faecalis exhibits a strong killing ability against F. nucleatum by generating an acidic micro-environment and producing hydrogen peroxide (H2O2). Finally, the binding and killing capacities of E. faecalis were found to be necessary to invade and dominate a pre-established in vitro F. nucleatum biofilm. Conclusions This study reveals multifaceted mechanisms underlying the physical binding and antagonistic interaction between F. nucleatum and E. faecalis, which could play a potential role in the shift of microbial composition in primary and secondary endodontic infections.

The Streptomyces scabiei Pathogenicity Factor Thaxtomin A Induces the Production of Phenolic Compounds in Potato Tubers.

The phytotoxin thaxtomin A (TA) is the key pathogenicity factor synthesized by the bacteria Streptomyces scabiei, the main causal agent of common scab of potato (Solanum tuberosum L.). TA treatment of potato tuber flesh produces a brown color that was attributed to necrosis. The intensity of TA-induced browning was generally thought to correlate with potato sensitivity to the disease. In this study, we found that TA-induced browning was much more intense in the potato tuber flesh of the common scab moderately resistant variety Russet Burbank (RB) than that observed in tubers of the disease-susceptible variety Yukon Gold (YG). However, there was no significant difference in the level of TA-induced cell death detected in both varieties, suggesting that tubers response to TA does not correlate with the level of sensitivity to common scab. TA-treated potato tuber tissues accumulated significantly higher levels of phenolic compounds than untreated controls, with a higher phenol content detected in RB TA-treated tissues than in those of YG. Browning was associated with a significant induction of the expression of genes of the phenylpropanoid pathway in RB tubers, indicating that TA activated this metabolic pathway. These results suggest that tuber flesh browning induced by TA is due to the accumulation of phenolic compounds. These phenolics may play a role in the protection of potato tubers against S. scabiei.

Heterochromatin in the fungal plant pathogen, Zymoseptoria tritici: Control of transposable elements, genome plasticity and virulence.

Heterochromatin is a repressive chromatin state that plays key roles in the functional organisation of eukaryotic genomes. In fungal plant pathogens, effector genes that are required for host colonization tend to be associated with heterochromatic regions of the genome that are enriched with transposable elements. It has been proposed that the heterochromatin environment silences effector genes in the absence of host and dynamic chromatin remodelling facilitates their expression during infection. Here we discuss this model in the context of the key wheat pathogen, Zymoseptoria tritici. We cover progress in understanding the deposition and recognition of heterochromatic histone post translational modifications in Z. tritici and the role that heterochromatin plays in control of genome plasticity and virulence.

High prevalence of resistance to third-generation cephalosporins detected among clinical isolates from sentinel healthcare facilities in Lagos, Nigeria

BackgroundAntimicrobial resistance (AMR) in bacterial pathogens is a worldwide concern that demands immediate attention. Most information on AMR originates from high-income countries and little is known about the burden in Africa, particularly Nigeria. Using four sentinel sites (General hospitals) in Lagos State, this study sought to estimate the burden of AMR.MethodsThis is a hospital-based surveillance using secondary health care centres. Four sites were randomly selected and included in the study. Clinical isolates were collected over a period of 6 months for each site from August 2020 to March 2021. All isolates were characterised and analysed for resistance to 15 antibiotics using the Kirby-Baur method. Multiplex PCR assay was used for the detection of Extended spectrum beta lactamase genes. Data analysis was done using SPSS version 27.0.ResultsFour hundred and ninety-nine (499) patients consented and participated in this study, consisting of 412 (82.6%) females and 87 (17.4%) males. The mean age ± SD of the participants was 33.9 ± 13.8 with a range of 1–89 years. The majority (90.8%) of the participants were outpatients. Two hundred and thirty-two (232) isolates were obtained from 219 samples, comprising of 120 (51.7%) Gram positive and 112 (48.3%) Gram negative organisms. Key bacterial pathogens isolated from this study included Staphylococcus aureus (22.8%), Escherichia coli (16.4%), Staphylococcus spp. (15.9%), Enterococcus spp. (7.3%) and Klebsiella pneumoniae (6.5%). There was high prevalence of multi-drug resistance (79.3%) among the isolates with 73.6% of Staphylococcus aureus phenotypically resistant to methicillin and 70% possessed the MecA gene. 76.5% of Enterococcus spp. isolated were Vancomycin resistant. Overall, resistance to Cephalosporins was most frequently/commonly observed (Cefotaxime 87.5%).ConclusionA high incidence of AMR was identified in clinical bacteria isolates from selected general hospitals in Lagos State, highlighting the necessity for the implementation of national action plans to limit the prevalence of AMR. Surveillance via collection of isolates has a lot of promise, especially in resource-limited environments.

Comparative Analysis of Novel Lytic Phages for Biological Control of Phytopathogenic Xanthomonas spp.

Xanthomonas is an important genus of plant-pathogenic bacteria that affects agronomic and economically important crops, causing serious economic losses. In fact, several Xanthomonas species are considered regulated quarantine pests. Due to the lack of effective control measures to treat plant-pathogenic bacteria, innovative control tools are needed to carry out integrated disease management. In this regard, bacteriophages (phages), viruses of bacteria, constitute a promising biocontrol tool. In this work, we report the isolation and characterization of 11 novel Xanthomonas arboricola pv. juglandis phages belonging to different families and genera of the class Caudoviricetes. Infectivity matrix in more than 60 isolates of different xanthomonads and other phytopathogenic bacteria suggests that these phages are specific to the Xanthomonas genus, with different host ranges depending on the isolates tested. Interestingly, some of these phages showed relevant features to be used as biocontrol tools to combat pathogenic Xanthomonas spp. as important as X. oryzae or X. citri. IMPORTANCE Phytopathogenic bacteria represent serious losses worldwide. The lack of current treatments has focused the spotlight on phages, viruses of bacteria, as very promising biocontrol tools. Phages are very specific and can help to control bacterial infections in crops, as is the case of xanthomonads-associated diseases. The discovery of new environmental phages with lytic capacity that can help to combat these pathogens is of special relevance, and it is necessary to implement phage isolation and characterization techniques to determine their host range and their genomic properties. The establishment of phage collections worldwide will allow their use as preventive, diagnostic, or therapeutic tools. Although there is still a long way to go, this work is a step forward in the implementation of new ecofriendly techniques to combat key pathogens in the field.

Aging envisage imbalance of the periodontium: A keystone in oral disease and systemic health.

Aging is a gradual and progressive deterioration of integrity across multiple organ systems that negatively affects gingival wound healing. The cellular responses associated with wound healing, such as collagen synthesis, cell migration, proliferation, and collagen contraction, have been shown to be lower in gingival fibroblasts (the most abundant cells from the connective gingival tissue) in aged donors than young donors. Cellular senescence is one of the hallmarks of aging, which is characterized by the acquisition of a senescence-associated secretory phenotype that is characterized by the release of pro-inflammatory cytokines, chemokines, growth factors, and proteases which have been implicated in the recruitment of immune cells such as neutrophils, T cells and monocytes. Moreover, during aging, macrophages show altered acquisition of functional phenotypes in response to the tissue microenvironment. Thus, inflammatory and resolution macrophage-mediated processes are impaired, impacting the progression of periodontal disease. Interestingly, salivary antimicrobial peptides, such as histatins, which are involved in various functions, such as antifungal, bactericidal, enamel-protecting, angiogenesis, and re-epithelization, have been shown to fluctuate with aging. Several studies have associated the presence of Porphyromonas gingivalis, a key pathogen related to periodontitis and apical periodontitis, with the progression of Alzheimer's disease, as well as gut, esophageal, and gastric cancers. Moreover, herpes simplex virus types 1 and 2 have been associated with the severity of periodontal disease, cardiovascular complications, and nervous system-related pathologies. This review encompasses the effects of aging on periodontal tissues, how P. gingivalis and HSV infections could favor periodontitis and their relationship with other pathologies.

'Targeting' the search: An upgraded structural and functional repository of antimicrobial peptides for biofilm studies (B-AMP v2.0) with a focus on biofilm protein targets.

Bacterial biofilms, often as multispecies communities, are recalcitrant to conventional antibiotics, making the treatment of biofilm infections a challenge. There is a push towards developing novel anti-biofilm approaches, such as antimicrobial peptides (AMPs), with activity against specific biofilm targets. In previous work, we developed Biofilm-AMP, a structural and functional repository of AMPs for biofilm studies (B-AMP v1.0) with more than 5000 structural models of AMPs and a vast library of AMP annotations to existing biofilm literature. In this study, we present an upgraded version of B-AMP, with a focus on existing and novel bacterial biofilm targets. B-AMP v2.0 hosts a curated collection of 2502 biofilm protein targets across 473 bacterial species, with structural protein models and functional annotations from PDB, UniProt, and PubMed databases. The biofilm targets can be searched for using the name of the source organism, and function and type of protein, and results include designated Target IDs (unique to B-AMP v2.0), UniProt IDs, 3D predicted protein structures, PDBQT files, pre-defined protein functions, and relevant scientific literature. To present an example of the combined applicability of both, the AMP and biofilm target libraries in the repository, we present two case studies. In the first case study, we expand an in silico pipeline to evaluate AMPs against a single biofilm target in the multidrug resistant, bacterial pathogen Corynebacterium striatum, using 3D protein-peptide docking models from previous work and Molecular Dynamics simulations (~1.2µs). In the second case study, we build an in silico pipeline to identify candidate AMPs (using AMPs with both anti-Gram positive and anti-Gram negative activity) against two biofilm targets with a common functional annotation in Pseudomonas aeruginosa and Staphylococcus aureus, widely-encountered bacterial co-pathogens. With its enhanced structural and functional capabilities, B-AMP v2.0 serves as a comprehensive resource for AMP investigations related to biofilm studies. B-AMP v2.0 is freely available at https://b-amp.karishmakaushiklab.com and will be regularly updated with structural models of AMPs and biofilm targets, as well as 3D protein-peptide interaction models for key biofilm-forming pathogens.

Dual functionality of Trichoderma: Biocontrol of Sclerotinia sclerotiorum and biostimulant of cotton plants.

Microbial crop protection products based on Trichoderma have the ability to display multifunctional roles in plant protection, such as pathogen parasitism, enhance nutrient availability and stimulate plant growth, and these traits can be used to enhance the overall agronomic performance of a variety of crops. In the current study, we explored the multifunctional potential of two indigenous Brazilian strains of Trichoderma (T. asperelloides CMAA 1584 and T. lentiforme CMAA 1585) for their capability of controlling Sclerotinia sclerotiorum, a key plant pathogen of cotton, and for their ability of growth promotion in cotton plants (Gossypium hirsutum). Both strains were able to solubilize mineral phosphorus (CaHPO4), to release volatile organic compounds that impaired the mycelial growth of S. sclerotiorum, and to promote the growth of cotton plants under greenhouse conditions. In dual culture, Trichoderma strains reduced the growth rate and the number of sclerotia formed by S. sclerotiorum. By treating sclerotia with conidial suspensions of these Trichoderma strains, a strong inhibition of the myceliogenic germination was observed, as a result of the marked mycoparasitic activity exerted on the sclerotia. The parasitism over S. sclerotiorum was more effective with T. asperelloides CMAA 1584, whilst the biostimulant effects on cotton growth were more pronounced with T. lentiforme CMAA 1585, which also showed a higher capacity of phosphate solubilization. Thus, T. asperelloides CMAA 1584 displays higher efficiency in controlling S. sclerotiorum, while T. lentiforme CMAA 1585 is more suitable as a biostimulant due to its ability to promote growth in cotton plants. Overall, these Trichoderma strains may be used in mixture to provide both pathogen control and promotion of plant growth, and this strategy will support growers in minimizing the use of synthetic fertilizers and fungicides against white mold in cotton crops.