The occurrence of viral zoonotic spillover (the transmission of viruses from animals to humans) has attracted worldwide attention due to mounting concerns regarding viral threats such as avian influenza, Hendra, monkeypox, Nipah and bat coronaviruses. It is evident that these events deviate significantly from natural occurrences, being the conflation of ecological, environmental and social factors that are profoundly altering the boundaries between the animal and human domains. Consequently, in order to comprehend both the contemporary and prospective drivers of zoonotic viral spillover, a coordinated, comprehensive global One Health response is essential. The objective of this review is to analyse prevalent pathways of transmission between animal reservoirs and human populations. This examination involves the analysis of historical cases, including those of SARS and Ebola, as well as recent occurrences, such as the global pandemic of SARS-CoV-2 (Covid-19). The objective of this review is to comprehend the fundamental mechanisms of cross-species transmission. The development of effective strategies to mitigate the emergence of zoonotic viruses and prevent future pandemics is contingent on a robust understanding of these mechanisms. This analysis is key to identifying pandemic pathogens and preventing the spread of zoonotic viruses. In conclusion, the review provides a thorough evaluation of current global strategies to prevent the spread of zoonotic viruses, highlighting gaps in our understanding and areas for further research.

Microorganisms can aggregate and organise into structured communities embedded within an exopolysaccharide-based matrsix, which serves as a protective barrier and a functional environment around microbial cells. The formation of biofilms is widely recognised as a pivotal factor in bacterial virulence, impeding the efficacy of antimicrobial agents and hindering immune responses, whilst concomitantly contributing to the development of antimicrobial resistance and the onset of persistent infections. Biofilm formation is a tightly regulated and dynamic process, controlled by quorum-sensing mechanisms and profoundly influenced by environmental factors and nutrient availability. The objective of this review is to elucidate the significance of biofilms in clinical settings, with a particular focus on their role in the pathogenesis of infectious diseases. Particular attention is devoted to biofilm-associated infections and infections related to invasive medical devices, with a particular emphasis on the most prevalent microbial pathogens, which include S. aureus, S. epidermidis, P. aeruginosa, E. coli, K. pneumoniae, A. baumannii and various species of Candida. Furthermore, the present review encompasses biofilm-associated chronic infections, conditions manifesting in predisposed patients, including individuals affected by cystic fibrosis. This review further examines the most recent strategies for combating antibiotic resistance in bacterial biofilms. This review focuses on recent biofilm pathogenesis advancements, with a focus on diagnosis challenges and the need for new ways to disrupt biofilm integrity.

The occurrence of viral zoonotic spillover (the transmission of viruses from animals to humans) has attracted worldwide attention due to mounting concerns regarding viral threats such as avian influenza, Hendra, monkeypox, Nipah and bat coronaviruses. It is evident that these events deviate significantly from natural occurrences, being the conflation of ecological, environmental and social factors that are profoundly altering the boundaries between the animal and human domains. Consequently, in order to comprehend both the contemporary and prospective drivers of zoonotic viral spillover, a coordinated, comprehensive global One Health response is essential. The purpose of the present review is to analyze prevailing pathways of transmission between animal reservoirs and human populations. This examination involves the analysis of historical cases, including those of SARS and Ebola, as well as recent occurrences, such as the global pandemic of SARS-CoV-2 (COVID-19). A secondary objective of this review is to comprehend the fundamental mechanisms of cross-species transmission. The development of effective strategies to mitigate the emergence of zoonotic viruses and prevent future pandemics is contingent on a robust understanding of these mechanisms. This analysis is key to identifying pandemic pathogens and preventing the spread of zoonotic viruses. In conclusion, the review provides a thorough evaluation of current global strategies to prevent the spread of zoonotic viruses, highlighting gaps in our understanding and areas for further research.

Recent advances in next-generation sequencing have revealed that the virome—the set of viruses residing in the gastrointestinal tract—is a fundamental yet still underexplored component of the human intestinal ecosystem. Despite the prevalence of research focused on bacterial alterations, recent findings suggest a significant role for viral elements within the intestinal microbiota, namely latent viruses, bacteriophages and eukaryotic viruses, in influencing brain health. Alterations in the gut virome may, in particular, contribute to the processes underlying brain aging, cognitive decline, and neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and multiple sclerosis (MS). This review highlights the potential of intestinal viruses to modulate gut barrier integrity, systemic immune response and neuroimmune inflammation. Such interactions could promote conditions of chronic neuroinflammation, alterations in synaptic plasticity, and neuronal vulnerability. A more comprehensive understanding of the role of the gut virome could potentially result in novel approaches to the early detection and treatment of neurocognitive disorders in adults and older individuals.

The aim of this study was to investigate the differences between nosocomial and community microorganisms isolated from patients with UTI by determining their bacterial profile, antibiotic resistance and ability to produce biofilms. A retrospective study, based on bacterial isolates from consecutive urine samples collected between January 2019 and December 2023, was conducted at a university hospital. The main pathogens isolated from both community and hospital samples were the same, but their frequency of isolation differed. Compared with community-associated cases, hospital-associated infections have more isolates of Acinetobacter baumanii complex. In contrast, Proteus mirabilis isolates were more prevalent in community than in hospital infections. In both hospital and community isolates, gram-positive bacteria showed a lower overall antimicrobial resistance (22%) compared to gram-negative bacteria (30%). The data demonstrated that individual strains exhibited disparate degrees of capacity for biofilm formation. Additionally, the data indicate an inverse correlation between biofilm production and antibiotic resistance. Isolates from community patients exhibited lower capacities for biofilm production in comparison to the capacities demonstrated by microorganisms isolated from nosocomial patients (29% and 35%, respectively). Area-specific surveillance studies can provide valuable information on UTI pathogens and antimicrobial resistance patterns, which can be useful in guiding empirical treatment.

The accelerated spread of bacterial resistance has been demonstrated to reduce the effectiveness of antibiotic treatments for infections, resulting in higher morbidity and mortality rates, as well as increased costs for livestock producers. It is expected that the majority of future antimicrobial use will be in animal production. The management of antimicrobial resistance (AMR) in the livestock sector poses significant challenges due to the multifaceted nature of the problem. In order to identify appropriate solutions to the rise of antimicrobial resistance, it is imperative that we have a comprehensive understanding of the disease dynamics underpinning the ways in which antimicrobial resistance is transmitted between humans and animals. Furthermore, in consideration of the anticipated requirement to satisfy the global demand for food, it is imperative that we guarantee that resistance is not transmitted or propagated during the treatment and disposal of animal waste, particularly from intensive farming. It is also crucial to formulate a research agenda to investigate how antibiotic resistance in animal faeces from livestock farming is affected by intensified farming activities. The review analyses the environment’s role in the transmission resistance chain and reviews methodologies for disrupting the link. A particular focus is placed on the limitations of the applied methodologies to reduce antimicrobial resistance in global animal production.

Antibiotic-resistant microbes represent a growing problem for modern medicine and public health. Projections indicate that deaths from such infections could reach 10 million per year by 2050. Healthcare associated infections (HAI) are among the most significant causes of mortality and morbidity in hospitals, impacting millions of patients globally. The emergence of HAI is associated with resistance to antimicrobials, rapidly worsening the patient’s condition. Antimicrobial resistance determines unresponsiveness to treatment, which can ultimately lead to severe complications such as sepsis and shock. It is estimated that one in every ten patients are susceptible to infection during their stay in hospital, with the microorganism responsible for the infection frequently proving resistant to antibiotics. Among the latter, CRE (carbapenem-resistant Enterobacteriaceae), CRAB (carbapenem-resistant Acinetobacter baumannii), CRPA (carbapenem-resistant Pseudomonas aeruginosa), vancomycin-resistant Enterococcus spp. and methicillin-resistant Staphylococcus aureus (MRSA), commonly referred to as ‘superbugs’, are a major cause of HAIs. The aim of the present study is to provide a comprehensive overview of the global epidemiology of healthcare-associated infections, with particular emphasis on their incidence, distribution over time, and correlation with the socioeconomic status of different countries. Furthermore, the review aims to evaluate the effectiveness of current preventive strategies in reducing the incidence and mortality associated with HAIs.

Antibiotic overuse in livestock is a major concern, as it contributes to the emergence of antibiotic resistance and may adversely affect both animal and human health. One important consequence is its impact on the gut microbiota, a complex microbial ecosystem essential for maintaining host health. A growing body of research highlights the critical role of a balanced gut microbiota in maintaining the integrity of the gut-microbiota–brain axis, a bidirectional communication network between the gastrointestinal tract and the central nervous system (CNS). Antibiotics introduced through the food chain and the environment can disrupt microbial balance, leading to dysbiosis and systemic inflammation. In this context, the concept of “One Health” is emphasized, which recognizes the deep interconnection between the health of humans, animals, and the environment to address the global problem of antibiotic resistance. Several animal studies highlight how dysbiosis can induce neuroinflammation and potentially damage the gut–brain barrier. This review explores the mechanisms by which antibiotic use in livestock alters the gut microbiota and compromises the gut-microbiota–brain axis integrity, outlining the implications for public health and the possible link with neurodegenerative conditions.

In recent decades, the world has observed the emergence and re-emergence of a multitude of previously non-existent or re-emerging infectious diseases, for which there is a paucity of timely and effective preventative measures. The WHO has published a catalogue of priority pathogens that are likely to trigger future epidemics, with the objective of designing effective prophylactic and therapeutic interventions. The rationale behind these interventions is rooted in a comprehensive understanding of the aetiology, epidemiology, and pathogenesis of the target diseases. While it is imperative to acknowledge the pivotal role that evolutionary changes in pathogens play, it is equally important to recognise the influence of a multifaceted interplay of factors on the emergence and re-emergence of infectious diseases. These include changes in human populations, the vectors and reservoirs of exposure, and environmental changes. This review summarises the aetiology, epidemiology, and pathogenesis of the ten WHO priority diseases, as well as those with high epidemic potential that are already the focus of specific control programme initiatives, such as HIV/AIDS, tuberculosis, and malaria diseases. Furthermore, this review concentrated on the means of addressing these infections through public health surveillance and response systems. Such systems must be designed to rapidly detect unusual and unexpected disease patterns, track and share information in real time, and rapidly mobilise global responses, which are the most important ways to effectively contain transmission.

Urinary tract infections (UTIs) are prevalent bacterial infections in both community and healthcare settings. They account for approximately 40% of all bacterial infections and require around 15% of all antibiotic prescriptions. Although antibiotics have traditionally been used to treat UTIs for several decades, the significant increase in antibiotic resistance in recent years has made many previously effective treatments ineffective. Biofilm on medical equipment in healthcare settings creates a reservoir of pathogens that can easily be transmitted to patients. Urinary catheter infections are frequently observed in hospitals and are caused by microbes that form a biofilm after a catheter is inserted into the bladder. Managing infections caused by biofilms is challenging due to the emergence of antibiotic resistance. Biofilms enable pathogens to evade the host's innate immune defences, resulting in long-term persistence. The incidence of sepsis caused by UTIs that have spread to the bloodstream is increasing, and drug-resistant infections may be even more prevalent. While the availability of upcoming tests to identify the bacterial cause of infection and its resistance spectrum is critical, it alone will not solve the problem; innovative treatment approaches are also needed. This review analyses the main characteristics of biofilm formation and drug resistance in recurrent uropathogen-induced UTIs. The importance of innovative and alternative therapies for combatting biofilm-caused UTI is emphasised.

Schistosomiasis is a neglected tropical disease that is prevalent in low- and middle-income countries. There are five human pathogenic species, of which Schistosoma haematobium, Schistosoma mansoni and Schistosoma japonicum are the most prevalent worldwide and cause the greatest burden of disease in terms of mortality and morbidity. In addition, hybrid schistosomes have been identified through molecular analysis. Human infection occurs when cercariae, the larval form of the parasite, penetrate the skin of people while bathing in contaminated waters such as lakes and rivers. Schistosomiasis can cause both urogenital and intestinal symptoms. Urogenital symptoms include haematuria, bladder fibrosis, kidney damage, and an increased risk of bladder cancer. Intestinal symptoms may include abdominal pain, sometimes accompanied by diarrhoea and blood in the stool. Schistosomiasis affects more than 250 million people and causes approximately 70 million Disability-Adjusted Life Years (DALYs), mainly in Africa, South America, and Asia. To control infection, it is essential to establish sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. This review provides an overview of schistosomiasis, with a focus on available diagnostic tools for Schistosoma spp. Current molecular detection methods and progress in the development of new diagnostics for schistosomiasis infection are also discussed.

Candida auris has been identified by the World Health Organization (WHO) as a critical priority pathogen on its latest list of fungi. C. auris infections are reported in the bloodstream and less commonly in the cerebrospinal fluid and abdomen, with mortality rates that range between 30% and 72%. However, no large-scale epidemiology studies have been reported until now. The diagnosis of C. auris infections can be challenging, particularly when employing conventional techniques. This can impede the early detection of outbreaks and the implementation of appropriate control measures. The yeast can easily spread between patients and in healthcare settings through contaminated environments or equipment, where it can survive for extended periods. Therefore, it would be desirable to screen patients for C. auris colonisation. This would allow facilities to identify patients with the disease and take appropriate prevention and control measures. It is frequently unsusceptible to drugs, with varying patterns of resistance observed among clades and geographical regions. This review provides updates on C. auris, including epidemiology, clinical characteristics, genomic analysis, evolution, colonisation, infection, identification, resistance profiles, therapeutic options, prevention, and control.

The issue of antibiotic resistance represents a significant threat that extends beyond human health, encompassing animal welfare and the sustainability of the natural environment. The inappropriate use of antibiotics, poor sanitation and inadequate control measures, have contributed to the emergence of drug-resistant bacteria, which can spread at the human-animal-environment interface. The documented presence of antimicrobials in agriculture, veterinary medicine and human medicine has convinced all stakeholders of the need to contribute to the development of a "One Health" approach, which recognises the interrelationships between animals, humans and their environment and the need to adopt a common strategy encompassing these sectors to limit the spread of antimicrobial resistance (AMR). Although a number of countries have implemented integrated surveillance systems to monitor antibiotic use and antimicrobial resistance, available data suggest that the use of antibiotics in humans, animals and the environment is increasing worldwide. Consequently, the emergence of antibiotic-resistant pathogens is becoming a recurring concern. This review provides a comprehensive overview of the measures that are necessary to be taken and implemented in order to guarantee global health security.

The issue of antibiotic resistance represents a significant threat that extends beyond human health, encompassing animal welfare and the sustainability of the natural environment. The inappropriate use of antibiotics, poor sanitation and inadequate control measures have contributed to the emergence of drug-resistant bacteria, which can spread at the human–animal–environment interface. The documented presence of antimicrobials in agriculture, veterinary medicine and human medicine has convinced all stakeholders of the need to contribute to the development of a “One Health” approach, which recognises the interrelationships between animals, humans and their environment and the need to adopt a common strategy encompassing these sectors to limit the spread of bacterial antimicrobial resistance (AMR). Although a number of countries have implemented integrated surveillance systems to monitor antibiotic use and antimicrobial resistance, available data suggest that the use of antibiotics in humans, animals and the environment is increasing worldwide. Consequently, the emergence of antibiotic-resistant pathogens is becoming a recurring concern. This review provides a comprehensive overview of the measures that are necessary to be taken and implemented in order to guarantee global health security.

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide, occurring in both community and healthcare settings. Although the clinical symptoms of UTIs are heterogeneous and range from uncomplicated (uUTIs) to complicated (cUTIs), most UTIs are usually treated empirically. Bacteria are the main causative agents of these infections, although more rarely, other microorganisms, such as fungi and some viruses, have been reported to be responsible for UTIs. Uropathogenic Escherichia coli (UPEC) is the most common causative agent for both uUTIs and cUTIs, followed by other pathogenic microorganisms, such as Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, and Staphylococcus spp. In addition, the incidence of UTIs caused by multidrug resistance (MDR) is increasing, resulting in a significant increase in the spread of antibiotic resistance and the economic burden of these infections. Here, we discuss the various factors associated with UTIs, including the mechanisms of pathogenicity related to the bacteria that cause UTIs and the emergence of increasing resistance in UTI pathogens.

About 150 million people around the world experience urinary tract infections (UTI) every year, with adult women 30 times more likely to develop a UTI than men [...]

New technologies and materials could help in this fight against healthcare-associated infections. As the majority of these infections are caused by antibiotic-resistant bacteria, the development of materials with intrinsic antibacterial properties is a promising field of research. We combined chitosan (CS), with antibacterial properties, with polyhedral oligomeric silsesquioxanes (POSS), a biocompatible polymer with physico-chemical, mechanical, and rheological properties, creating a hydrogel using cross-linking agent genipin. The antibacterial properties of CS and CS-POSS hydrogels were investigated against nosocomial Gram-positive and Gram-negative bacteria both in terms of membrane damage and surface charge variations, and finally, the anti-biofilm property was studied through confocal microscopy. Both materials showed a good antibacterial capacity against all analyzed strains, both in suspension, with % decreases between 36.36 and 73.58 for CS and 29.86 and 66.04 for CS-POSS, and in plates with % decreases between 55.29 and 78.32 and 17.00 and 53.99 for CS and CS-POSS, respectively. The treated strains compared to the baseline condition showed an important membrane damage, which also determined a variation of surface charges, and finally, for both hydrogels, a remarkable anti-biofilm property was highlighted. Our findings showed a possible future use of these biocompatible materials in the manufacture of medical and surgical devices with intrinsic antibacterial and anti-biofilm properties.

Antibiotics have played a crucial role in the reduction in the incidence of TB globally as evidenced by the fact that before the mid-20th century, the mortality rate within five years of the onset of the disease was 50%. The use of antibiotics has eliminated TB as a devastating disease, but the challenge of resistance to anti-TB drugs, which had already been described at the time of the introduction of streptomycin, has become a major global issue in disease management. Mismanagement of multidrug-resistant tuberculosis (MDR-TB) cases, resulting from intermittent drug use, prescription errors, and non-compliance of patients, has been identified as a critical risk factor for the development of extensively drug-resistant tuberculosis (XDR-TB). Antimicrobial resistance (AMR) in TB is a multi-factorial, complex problem of microbes evolving to escape antibiotics, the gradual decline in antibiotic development, and different economic and social conditions. In this review, we summarize recent advances in our understanding of how Mycobacterium tuberculosis evolves drug resistance. We also highlight the importance of developing shorter regimens that rapidly reach bacteria in diverse host environments, eradicating all mycobacterial populations and preventing the evolution of drug resistance. Lastly, we also emphasize that the current burden of this ancient disease is driven by a combination of complex interactions between mycobacterial and host factors, and that only a holistic approach that effectively addresses all the critical issues associated with drug resistance will limit the further spread of drug-resistant strains throughout the community.

The global burden of bacterial resistance remains one of the most serious public health concerns. Infections caused by multiresistant (MDR) bacteria in critically ill patients require immediate empirical treatment, which may not only be ineffective due to the resistance of MDR bacteria to multiple classes of antibiotics, but may also contribute to the selection and spread of antimicrobial resistance. Both the WHO and the ECDC consider carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Acinetobacter baumannii (CRAB) to be the highest priority. The ability to form biofilm and the acquisition of multiple drug resistance, in particular to carbapenems, have made these pathogens particularly difficult to treat. They are a growing cause of healthcare-associated infections and a significant threat to public health, associated with a high mortality rate. Moreover, co-colonization with these pathogens in critically ill patients was found to be a significant predictor for in-hospital mortality. Importantly, they have the potential to spread resistance using mobile genetic elements. Given the current situation, it is clear that finding new ways to combat antimicrobial resistance can no longer be delayed. The aim of this review was to evaluate the literature on how these pathogens contribute to the global burden of AMR. The review also highlights the importance of the rational use of antibiotics and the need to implement antimicrobial stewardship principles to prevent the transmission of drug-resistant organisms in healthcare settings. Finally, the review discusses the advantages and limitations of alternative therapies for the treatment of infections caused by these "titans" of antibiotic resistance.

Coronavirus disease 2019 (COVID-19) is a potentially serious acute respiratory infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Since the World Health Organization (WHO) declared COVID-19 a global pandemic, the virus has spread to more than 200 countries with more than 500 million cases and more than 6 million deaths reported globally. It has long been known that viral respiratory tract infections predispose patients to bacterial infections and that these co-infections often have an unfavourable clinical outcome. Moreover, nosocomial infections, also known as healthcare-associated infections (HAIs), are those infections that are absent at the time of admission and acquired after hospitalization. However, the impact of coinfections or secondary infections on the progression of COVID-19 disease and its lethal outcome is still debated. The aim of this review was to assess the literature on the incidence of bacterial co-infections and superinfections in patients with COVID-19. The review also highlights the importance of the rational use of antibiotics in patients with COVID-19 and the need to implement antimicrobial stewardship principles to prevent the transmission of drug-resistant organisms in healthcare settings. Finally, alternative antimicrobial agents to counter the emergence of multidrug-resistant bacteria causing healthcare-associated infections in COVID-19 patients will also be discussed.