Browsing by Author "Jankovic, Marko (57218194970)"

Background/Objectives: Antimicrobial resistance poses a major public health challenge. The World Health Organization has identified 15 priority pathogens that require prompt development of new antibiotics. This review systematically evaluates the antibacterial resistance of the most significant bacterial pathogens, currently available treatment options, as well as complementary approaches for the management of infections caused by the most challenging multidrug-resistant (MDR) bacteria. For carbapenem-resistant Gram-negative bacteria, treatment options include combinations of beta-lactam antibiotics and beta-lactamase inhibitors, a novel siderophore cephalosporin, known as cefiderocol, as well as older antibiotics like polymixins and tigecycline. Treatment options for Gram-positive bacteria are vancomycin, daptomycin, linezolid, etc. Although the development of new antibiotics has stagnated, various agents with antibacterial properties are currently in clinical and preclinical trials. Non-antibiotic strategies encompass antibiotic potentiators, bacteriophage therapy, antivirulence therapeutics, antimicrobial peptides, antibacterial nanomaterials, host-directed therapy, vaccines, antibodies, plant-based products, repurposed drugs, as well as their combinations, including those used alongside antibiotics. Significant challenges exist in developing new antimicrobials, particularly related to scientific and technical issues, along with policy and economic factors. Currently, most of the alternative options are not part of routine treatment protocols. Conclusions and Future Directions: There is an urgent need to expedite the development of new strategies for treating infections caused by MDR bacteria. This requires a multidisciplinary approach that involves collaboration across research, healthcare, and regulatory bodies. Suggested approaches are crucial for addressing this challenge and should be backed by rational antibiotic use, enhanced infection control practices, and improved surveillance systems for emerging pathogens. © 2025 by the authors.

Background/Objectives: Antimicrobial resistance poses a major public health challenge. The World Health Organization has identified 15 priority pathogens that require prompt development of new antibiotics. This review systematically evaluates the antibacterial resistance of the most significant bacterial pathogens, currently available treatment options, as well as complementary approaches for the management of infections caused by the most challenging multidrug-resistant (MDR) bacteria. For carbapenem-resistant Gram-negative bacteria, treatment options include combinations of beta-lactam antibiotics and beta-lactamase inhibitors, a novel siderophore cephalosporin, known as cefiderocol, as well as older antibiotics like polymixins and tigecycline. Treatment options for Gram-positive bacteria are vancomycin, daptomycin, linezolid, etc. Although the development of new antibiotics has stagnated, various agents with antibacterial properties are currently in clinical and preclinical trials. Non-antibiotic strategies encompass antibiotic potentiators, bacteriophage therapy, antivirulence therapeutics, antimicrobial peptides, antibacterial nanomaterials, host-directed therapy, vaccines, antibodies, plant-based products, repurposed drugs, as well as their combinations, including those used alongside antibiotics. Significant challenges exist in developing new antimicrobials, particularly related to scientific and technical issues, along with policy and economic factors. Currently, most of the alternative options are not part of routine treatment protocols. Conclusions and Future Directions: There is an urgent need to expedite the development of new strategies for treating infections caused by MDR bacteria. This requires a multidisciplinary approach that involves collaboration across research, healthcare, and regulatory bodies. Suggested approaches are crucial for addressing this challenge and should be backed by rational antibiotic use, enhanced infection control practices, and improved surveillance systems for emerging pathogens. © 2025 by the authors.

Here, we report on a serendipitous finding of a chryso-like virus associated with Culex pipiens mosquitos in the course of study aimed to detect and characterize West Nile virus (WNV) circulating in mosquitos in Serbia, Southern Europe. Upon initial detection of unexpected product in a PCR protocol for partial WNV NS5 gene amplification, further confirmation and identification was obtained through additional PCR and Sanger sequencing experiments. Bioinformatic and phylogenetic analysis identified the obtained sequences as Xanthi chryso-like virus (XCLV). The finding is particular for the fact that it associates XCLV with a new potential vector species and documents a novel geographical area of its distribution. © 2023 by the authors.

Here, we report on a serendipitous finding of a chryso-like virus associated with Culex pipiens mosquitos in the course of study aimed to detect and characterize West Nile virus (WNV) circulating in mosquitos in Serbia, Southern Europe. Upon initial detection of unexpected product in a PCR protocol for partial WNV NS5 gene amplification, further confirmation and identification was obtained through additional PCR and Sanger sequencing experiments. Bioinformatic and phylogenetic analysis identified the obtained sequences as Xanthi chryso-like virus (XCLV). The finding is particular for the fact that it associates XCLV with a new potential vector species and documents a novel geographical area of its distribution. © 2023 by the authors.

West Nile Virus (WNV) is considered one of the most widely distributed arboviruses worldwide. In 2018, Serbia was among the European countries reporting the highest number of WNV cases. This study aimed to characterize WNV strains circulating in Serbia, and to estimate the pathways and dynamics of WNV-2 spread in the Balkans and globally through the phylogenetic approach. Fifty newly generated NS5 Serbian sequences were found to belong to WNV lineage 2. Phylodynamic analyses of the Balkan clade indicated the potential for an increase in genetic diversity and structure of virus populations. Presented phylogeographic analyses implied four instances of long-distance WNV-2 migration from Africa to Europe, during the 1940s to 1950s, while further dissemination of WNV-2 originated in Hungary in mid-1970s and subsequently spread to Austria and Serbia. Extensive dispersion took place during the 1990s–2000s, as the virus spread from Austria to central and western Europe, and from Hungary to the Balkans. Continuous phylogeography analysis of the Balkans WNV-2 clade implied the central role of Serbia for WNV dissemination across the Balkan peninsula. Furthermore, previously undocumented instance of intercontinental migration of WNV-2 from Europe to Asia was implied. In-depth phylogenetic investigation into the global distribution of WNV-2 may provide valuable insights into the prediction and prevention of potential epidemics. © 2024 Wiley Periodicals LLC.

West Nile Virus (WNV) is considered one of the most widely distributed arboviruses worldwide. In 2018, Serbia was among the European countries reporting the highest number of WNV cases. This study aimed to characterize WNV strains circulating in Serbia, and to estimate the pathways and dynamics of WNV-2 spread in the Balkans and globally through the phylogenetic approach. Fifty newly generated NS5 Serbian sequences were found to belong to WNV lineage 2. Phylodynamic analyses of the Balkan clade indicated the potential for an increase in genetic diversity and structure of virus populations. Presented phylogeographic analyses implied four instances of long-distance WNV-2 migration from Africa to Europe, during the 1940s to 1950s, while further dissemination of WNV-2 originated in Hungary in mid-1970s and subsequently spread to Austria and Serbia. Extensive dispersion took place during the 1990s–2000s, as the virus spread from Austria to central and western Europe, and from Hungary to the Balkans. Continuous phylogeography analysis of the Balkans WNV-2 clade implied the central role of Serbia for WNV dissemination across the Balkan peninsula. Furthermore, previously undocumented instance of intercontinental migration of WNV-2 from Europe to Asia was implied. In-depth phylogenetic investigation into the global distribution of WNV-2 may provide valuable insights into the prediction and prevention of potential epidemics. © 2024 Wiley Periodicals LLC.

Background: Usutu virus (USUV) is an emerging mosquito-borne Flavivirus, with birds as the main zoonotic reservoir. Humans are accidental hosts and mostly develop mild or even asymptomatic infections, although severe complications such as encephalitis can also arise. Detailed characterization of the pathogen's phylogenetics may offer valuable insights into the prediction and prevention of potential epidemics; however, lack of uniformity and the number of available USUV sequences worldwide hamper comprehensive investigation. Aim: The study aimed to investigate USUV spatio-temporal dispersal inter- and intracontinentally and to estimate the dynamics of viral spread within Europe. Methods: Phylogeographic and phylodynamic analyses were done using advanced phylogenetic methods implemented in Beast 1.10.4 and Beast 2.6.4 software packages. Results: Herein, we report on a new USUV isolate from Culex pipiens collected in 2019 from Serbia. The results of this research revealed two newly described intercontinental migration events of USUV from Africa to Germany in the 1970s and from Africa to the Middle East (Israel) in the late 90s. Finally, phylodynamic analysis substantiated the ongoing active expansion of USUV in Europe. Conclusion: The data would imply a high potential for further USUV expansion in Europe. Detailed phylogenetic characterization of the pathogen may offer valuable insights into prediction and prevention of potential epidemics; however, lack of uniformity and number of available USUV sequences worldwide hampers comprehensive investigation. This study draws attention to the need for upscaling USUV surveillance. Copyright © 2023 Siljic, Sehovic, Jankovic, Stamenkovic, Loncar, Todorovic, Stanojevic and Cirkovic.

Background: Usutu virus (USUV) is an emerging mosquito-borne Flavivirus, with birds as the main zoonotic reservoir. Humans are accidental hosts and mostly develop mild or even asymptomatic infections, although severe complications such as encephalitis can also arise. Detailed characterization of the pathogen's phylogenetics may offer valuable insights into the prediction and prevention of potential epidemics; however, lack of uniformity and the number of available USUV sequences worldwide hamper comprehensive investigation. Aim: The study aimed to investigate USUV spatio-temporal dispersal inter- and intracontinentally and to estimate the dynamics of viral spread within Europe. Methods: Phylogeographic and phylodynamic analyses were done using advanced phylogenetic methods implemented in Beast 1.10.4 and Beast 2.6.4 software packages. Results: Herein, we report on a new USUV isolate from Culex pipiens collected in 2019 from Serbia. The results of this research revealed two newly described intercontinental migration events of USUV from Africa to Germany in the 1970s and from Africa to the Middle East (Israel) in the late 90s. Finally, phylodynamic analysis substantiated the ongoing active expansion of USUV in Europe. Conclusion: The data would imply a high potential for further USUV expansion in Europe. Detailed phylogenetic characterization of the pathogen may offer valuable insights into prediction and prevention of potential epidemics; however, lack of uniformity and number of available USUV sequences worldwide hampers comprehensive investigation. This study draws attention to the need for upscaling USUV surveillance. Copyright © 2023 Siljic, Sehovic, Jankovic, Stamenkovic, Loncar, Todorovic, Stanojevic and Cirkovic.

Although not regarded as an oncogenic pathogen, the human cytomegalovirus (HCMV) has been associated with a wide array of malignancies. Conversely, a number of studies report on possible anti-tumor properties of the virus, apparently mediated via HCMV-galvanized T-cell tumor killing; these were recently being investigated in clinical trials for the purposes of anti-cancer treatment by means of dendritic cell vaccines and HCMV-specific cytotoxic T cells. In the present study, we have analyzed the relation between a complement of head-and-neck tumors and HCMV infection across 73 countries worldwide using Spearman correlation, univariate and multivariate regression analysis. Intriguingly, HCMV was found to be pro-oncogenic in patients with nasopharyngeal carcinoma; contrarywise, the virus manifested an inverse (i.e., anti-tumor) association with the tumors of the lip/oral region and the salivary glands. Although this putative protective effect was noted initially for thyroid neoplasia and hypopharyngeal tumors as well, after multivariate regression analysis the connection did not hold. There was no association between laryngeal cancer and HCMV infection. It would appear that, depending on the tissue, HCMV may exert both protective and oncogenic effects. The globally observed protective feature of the virus could potentially be utilized in future therapeutic approaches for salivary tumors and neoplasia in the lip/oral region. As correlation does not necessarily imply causation, more in-depth molecular analyses from comprehensive clinical studies are warranted to substantiate our findings. © 2024 by the authors.

Although not regarded as an oncogenic pathogen, the human cytomegalovirus (HCMV) has been associated with a wide array of malignancies. Conversely, a number of studies report on possible anti-tumor properties of the virus, apparently mediated via HCMV-galvanized T-cell tumor killing; these were recently being investigated in clinical trials for the purposes of anti-cancer treatment by means of dendritic cell vaccines and HCMV-specific cytotoxic T cells. In the present study, we have analyzed the relation between a complement of head-and-neck tumors and HCMV infection across 73 countries worldwide using Spearman correlation, univariate and multivariate regression analysis. Intriguingly, HCMV was found to be pro-oncogenic in patients with nasopharyngeal carcinoma; contrarywise, the virus manifested an inverse (i.e., anti-tumor) association with the tumors of the lip/oral region and the salivary glands. Although this putative protective effect was noted initially for thyroid neoplasia and hypopharyngeal tumors as well, after multivariate regression analysis the connection did not hold. There was no association between laryngeal cancer and HCMV infection. It would appear that, depending on the tissue, HCMV may exert both protective and oncogenic effects. The globally observed protective feature of the virus could potentially be utilized in future therapeutic approaches for salivary tumors and neoplasia in the lip/oral region. As correlation does not necessarily imply causation, more in-depth molecular analyses from comprehensive clinical studies are warranted to substantiate our findings. © 2024 by the authors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has been evolving rapidly causing emergence of new variants and health uncertainties. Monitoring the evolution of the virus was of the utmost importance for public health interventions and the development of national and global mitigation strategies. Here, we report national data on the emergence of new variants, their distribution, and dynamics in a 3-year study conducted from March 2020 to the end of January 2023 in the Republic of Serbia. Nasopharyngeal and oropharyngeal swabs from 2,398 COVID-19-positive patients were collected and sequenced using three different next generation technologies: Oxford Nanopore, Ion Torrent, and DNBSeq. In the subset of 2,107 SARS-CoV-2 sequences which met the quality requirements, detection of mutations, assignment to SARS-CoV-2 lineages, and phylogenetic analysis were performed. During the 3-year period, we detected three variants of concern, namely, Alpha (5.6%), Delta (7.4%), and Omicron (70.3%) and one variant of interest—Omicron recombinant “Kraken” (XBB1.5) (<1%), whereas 16.8% of the samples belonged to other SARS-CoV-2 (sub)lineages. The detected SARS-CoV-2 (sub)lineages resulted in eight COVID-19 pandemic waves in Serbia, which correspond to the pandemic waves reported in Europe and the United States. Wave dynamics in Serbia showed the most resemblance with the profile of pandemic waves in southern Europe, consistent with the southeastern European location of Serbia. The samples were assigned to sixteen SARS-CoV-2 Nextstrain clades: 20A, 20B, 20C, 20D, 20E, 20G, 20I, 21J, 21K, 21L, 22A, 22B, 22C, 22D, 22E, and 22F and six different Omicron recombinants (XZ, XAZ, XAS, XBB, XBF, and XBK). The 10 most common mutations detected in the coding and untranslated regions of the SARS-CoV-2 genomes included four mutations affecting the spike protein (S:D614G, S:T478K, S:P681H, and S:S477N) and one mutation at each of the following positions: 5′-untranslated region (5’UTR:241); N protein (N:RG203KR); NSP3 protein (NSP3:F106F); NSP4 protein (NSP4:T492I); NSP6 protein (NSP6: S106/G107/F108 - triple deletion), and NSP12b protein (NSP12b:P314L). This national-level study is the most comprehensive in terms of sequencing and genomic surveillance of SARS-CoV-2 during the pandemic in Serbia, highlighting the importance of establishing and maintaining good national practice for monitoring SARS-CoV-2 and other viruses circulating worldwide. Copyright © 2024 Novkovic, Banovic Djeri, Ristivojevic, Knezevic, Jankovic, Tanasic, Radojicic, Keckarevic, Vidanovic, Tesovic, Skakic, Tolinacki, Moric and Djordjevic.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has been evolving rapidly causing emergence of new variants and health uncertainties. Monitoring the evolution of the virus was of the utmost importance for public health interventions and the development of national and global mitigation strategies. Here, we report national data on the emergence of new variants, their distribution, and dynamics in a 3-year study conducted from March 2020 to the end of January 2023 in the Republic of Serbia. Nasopharyngeal and oropharyngeal swabs from 2,398 COVID-19-positive patients were collected and sequenced using three different next generation technologies: Oxford Nanopore, Ion Torrent, and DNBSeq. In the subset of 2,107 SARS-CoV-2 sequences which met the quality requirements, detection of mutations, assignment to SARS-CoV-2 lineages, and phylogenetic analysis were performed. During the 3-year period, we detected three variants of concern, namely, Alpha (5.6%), Delta (7.4%), and Omicron (70.3%) and one variant of interest—Omicron recombinant “Kraken” (XBB1.5) (<1%), whereas 16.8% of the samples belonged to other SARS-CoV-2 (sub)lineages. The detected SARS-CoV-2 (sub)lineages resulted in eight COVID-19 pandemic waves in Serbia, which correspond to the pandemic waves reported in Europe and the United States. Wave dynamics in Serbia showed the most resemblance with the profile of pandemic waves in southern Europe, consistent with the southeastern European location of Serbia. The samples were assigned to sixteen SARS-CoV-2 Nextstrain clades: 20A, 20B, 20C, 20D, 20E, 20G, 20I, 21J, 21K, 21L, 22A, 22B, 22C, 22D, 22E, and 22F and six different Omicron recombinants (XZ, XAZ, XAS, XBB, XBF, and XBK). The 10 most common mutations detected in the coding and untranslated regions of the SARS-CoV-2 genomes included four mutations affecting the spike protein (S:D614G, S:T478K, S:P681H, and S:S477N) and one mutation at each of the following positions: 5′-untranslated region (5’UTR:241); N protein (N:RG203KR); NSP3 protein (NSP3:F106F); NSP4 protein (NSP4:T492I); NSP6 protein (NSP6: S106/G107/F108 - triple deletion), and NSP12b protein (NSP12b:P314L). This national-level study is the most comprehensive in terms of sequencing and genomic surveillance of SARS-CoV-2 during the pandemic in Serbia, highlighting the importance of establishing and maintaining good national practice for monitoring SARS-CoV-2 and other viruses circulating worldwide. Copyright © 2024 Novkovic, Banovic Djeri, Ristivojevic, Knezevic, Jankovic, Tanasic, Radojicic, Keckarevic, Vidanovic, Tesovic, Skakic, Tolinacki, Moric and Djordjevic.

Background/Objectives: Antimicrobial resistance (AMR) poses a significant public health threat, leading to increased mortality. The World Health Organization has established a priority list highlighting critical multidrug-resistant (MDR) pathogens that demand urgent research on antimicrobial treatments. Considering this and the fact that new antibiotics are only sporadically approved, natural antibacterial agents have seen a resurgence in interest as potential alternatives to conventional antibiotics and chemotherapeutics. Natural antibacterials, derived from microorganisms, higher fungi, plants, animals, natural minerals, and food sources, offer diverse mechanisms of action against MDR pathogens. Here, we present a comprehensive summary of antibacterial agents from natural sources, including a brief history of their application and highlighting key strategies for using microorganisms (microbiopredators, such as bacteriophages), plant extracts and essential oils, minerals (e.g., silver and copper), as well as compounds of animal origin, such as milk or even venoms. The review also addresses the role of prebiotics, probiotics, and antimicrobial peptides, as well as novel formulations such as nanoparticles. The mechanisms of action of these compounds, such as terpenoids, alkaloids, and phenolic compounds, are explored alongside the challenges for their application, e.g., extraction, formulation, and pharmacokinetics. Conclusions: Future research should focus on developing eco-friendly, sustainable antimicrobial agents and validating their safety and efficacy through clinical trials. Clear regulatory frameworks are essential for integrating these agents into clinical practice. Despite challenges, natural sources offer transformative potential for combating AMR and promoting sustainable health solutions. © 2025 by the authors.

Background/Objectives: Antimicrobial resistance (AMR) poses a significant public health threat, leading to increased mortality. The World Health Organization has established a priority list highlighting critical multidrug-resistant (MDR) pathogens that demand urgent research on antimicrobial treatments. Considering this and the fact that new antibiotics are only sporadically approved, natural antibacterial agents have seen a resurgence in interest as potential alternatives to conventional antibiotics and chemotherapeutics. Natural antibacterials, derived from microorganisms, higher fungi, plants, animals, natural minerals, and food sources, offer diverse mechanisms of action against MDR pathogens. Here, we present a comprehensive summary of antibacterial agents from natural sources, including a brief history of their application and highlighting key strategies for using microorganisms (microbiopredators, such as bacteriophages), plant extracts and essential oils, minerals (e.g., silver and copper), as well as compounds of animal origin, such as milk or even venoms. The review also addresses the role of prebiotics, probiotics, and antimicrobial peptides, as well as novel formulations such as nanoparticles. The mechanisms of action of these compounds, such as terpenoids, alkaloids, and phenolic compounds, are explored alongside the challenges for their application, e.g., extraction, formulation, and pharmacokinetics. Conclusions: Future research should focus on developing eco-friendly, sustainable antimicrobial agents and validating their safety and efficacy through clinical trials. Clear regulatory frameworks are essential for integrating these agents into clinical practice. Despite challenges, natural sources offer transformative potential for combating AMR and promoting sustainable health solutions. © 2025 by the authors.