Search Results (52)

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen with significant clinical relevance in both human and veterinary medicine. Despite its well-documented role in hospital-acquired infections in human healthcare settings, its persistence and transmission within veterinary clinics remain underexplored. This review highlights the overlooked status of veterinary facilities as environmental reservoirs and amplification points for multidrug-resistant (MDR) P. aeruginosa, emphasizing their relevance to One Health surveillance. We examine the bacterium’s environmental survival strategies, including biofilm formation, resistance to disinfectants, and tolerance to nutrient-poor conditions that facilitate the long-term colonization of moist surfaces, drains, medical equipment, and plumbing systems. Common transmission vectors are identified, including asymptomatic animal carriers, contaminated instruments, and the hands of veterinary staff. The review synthesizes current data on antimicrobial resistance in environmental isolates, revealing frequent expression of efflux pumps and mobile resistance genes, and documents the potential for zoonotic transmission to staff and pet owners. Key gaps in environmental monitoring, infection control protocols, and genomic surveillance are identified, with a call for standardized approaches tailored to the veterinary context. Control strategies, including mechanical biofilm disruption, disinfectant cycling, effluent monitoring, and staff hygiene training, are evaluated for feasibility and impact. The article concludes with a One Health framework outlining cross-species and environmental transmission pathways. It advocates for harmonized surveillance, infrastructure improvements, and intersectoral collaboration to reduce the risk posed by MDR P. aeruginosa within veterinary clinical environments and beyond. By addressing these blind spots, veterinary facilities can become proactive partners in antimicrobial stewardship and global resistance mitigation. Full article

The excessive use of antimicrobials drives the emergence of multidrug resistance (MDR) in bacterial strains, which harbor resistance genes to survive under diverse drug pressures. Such resistance can result in life-threatening infections. The predominance of MDR Pseudomonas spp. poses significant challenges to public health and environmental sustainability, particularly in ecosystems affected by human activities. Characterizing MDR Pseudomonas spp. is crucial for developing effective diagnostic tools and biosecurity protocols, with broader implications for managing other pathogenic bacteria. Strains were diagnosed through 16S rRNA PCR and sequencing, complemented by phylogenetic analysis to evaluate local and global evolutionary connections. Antibiotic susceptibility tests revealed extensive resistance across multiple classes, with MIC values surpassing clinical breakpoints. This study examined the genetic diversity, resistance potential, and phylogenetic relationships among Pseudomonas aeruginosa strain DG2 and Pseudomonas fluorescens strain FM3, which were isolated from solid waste dump sites (n = 30) and dairy farms (n = 22) in West Bengal, India. Phylogenetic analysis reveals distinct clusters that highlight significant geographic linkages and genetic variability among the strains. Significant biofilm production under antibiotic exposure markedly increased resistance levels. RAPD-PCR profiling revealed substantial genetic diversity among the isolates, indicating variations in their genetic makeup. In contrast, SDS-PAGE analysis provided insights into the protein expression patterns that are activated by stress, which are closely linked to MDR. This dual approach offers a clearer perspective on their adaptive responses to environmental stressors. This study underscores the need for vigilant monitoring of MDR Pseudomonas spp. in anthropogenically impacted environments to mitigate risks to human and animal health. Surveillance strategies combining phenotypic and molecular approaches are essential to assess the risks posed by resilient pathogens. Solid waste and dairy farm ecosystems emerge as critical reservoirs for the evolution and dissemination of MDR Pseudomonas spp. Full article

Background: Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to multiple antibiotics, posing substantial challenges for treatment. Reports of acquired resistance are increasing, underscoring the need for global surveillance. Objective: This systematic review and meta-analysis aimed to determine the global prevalence of antibiotic-resistant B. pseudomallei isolated from human clinical cases, with a focus on regional differences and variations in antimicrobial susceptibility testing methods. Methods: We systematically searched PubMed, Scopus, and Embase for studies reporting resistance in clinical B. pseudomallei isolates, following PRISMA guidelines. Pooled resistance rates to 11 antibiotics were calculated using a random-effect model. Subgroup analyses were performed based on geographical region and testing methodology (MIC vs. disk diffusion). Results: Twelve studies comprising 10,391 isolates were included. Resistance rates varied across antibiotics, with the highest pooled resistance observed for tigecycline (46.3%) and ciprofloxacin (38.3%). Ceftazidime (CAZ) and trimethoprim–sulfamethoxazole (SXT), commonly used first-line agents, showed resistance rates of 5.3% and 4.2%, respectively. Subgroup analyses of CAZ and SXT revealed significantly higher resistance in studies from Asia compared to Australia and America (p value < 0.0001). Disk diffusion methods tended to overestimate resistance compared to MIC-based approaches, which revealed non-significant differences for CAZ (p value = 0.5343) but significant differences for SXT (p value < 0.0001). Conclusions: Antibiotic resistance in B. pseudomallei exhibits regional variation and is influenced by the susceptibility testing method used. Surveillance programs and standardized antimicrobial susceptibility testing protocols are essential to guide effective treatment strategies and ensure accurate resistance reporting. Full article

Background: Antimicrobial resistance (AMR) poses significant risks to human and animal health, while the environment can contribute to its spread. National AMR surveillance programs are pivotal for assessing AMR prevalence, trends, and intervention outcomes; however, integrating advanced surveillance tools can be difficult. This pilot study, conducted by FAO ECTAD Indonesia and DGLAHS, the Indonesian Ministry of Agriculture, evaluated the costs and benefits of integrating the Nanopore MinION, Illumina MiSeq, and Sensititre system into a culture-based slaughterhouse–river surveillance system. Methods: Water samples were collected from six chicken slaughterhouses and adjacent rivers (pre- and post-treatment effluent, upstream, and downstream). Culture-based ESBL and general E. coli concentrations were estimated via the WHO Tricycle Protocol, while isolates (n = 42) were sequenced (MinION, MiSeq) and antimicrobial susceptibility testing conducted (Sensititre). Results: The Tricycle Protocol results provided estimates of effluent and river concentrations of ESBL and general E. coli identifying ESBL-to-general E. coli ratios of 13.8% and 6.2%, respectively. Compared to hybrid sequencing assemblies, MinION had a higher concordance than MiSeq for ARG identification (98%), virulence genes (96%), and locations for both (predominately plasmids). Furthermore, MinION concordance with Sensititre AST was 91%. Conclusions: Cost–benefit comparisons suggest sequencing can complement culture-based methods but is dependent on the value placed on the additional information gained. Full article

Antimicrobial resistance (AMR) constitutes a critical threat to global public health, with carbapenem-resistant Enterobacterales (CRE) presenting significant challenges due to their resistance to last-line antibiotics. Among these, New Delhi metallo-beta-lactamase (NDM)-producing Klebsiella pneumoniae (KP) is of particular concern. This study describes an outbreak of NDM-producing KP in the hematology unit of the University Hospital of Verona, Italy. This represents the second reported hospital outbreak of this strain in Italy, and the first to occur within a hematology ward. The outbreak involved four patients, all of whom were identified through active surveillance and microbiological screening. In response, a multidisciplinary team implemented a series of infection prevention and control (IPC) measures, which included enhanced environmental cleaning, strict hand hygiene protocols, patient isolation, and the development of a tailored IPC checklist. The outbreak was effectively contained within three weeks following the identification of the last case. This outcome underscores the importance of rapid and coordinated responses to NDM-producing KP outbreaks. This case study emphasizes the necessity of robust IPC protocols, rapid intervention, and continuous staff education in mitigating the spread of multidrug-resistant pathogens in healthcare settings. It further highlights the urgent need for healthcare systems to be adequately prepared and resilient in addressing the growing threat of AMR. Full article

Background: During the COVID-19 pandemic, the emergence of multidrug-resistant (MDR) pathogens, driven by heightened antibiotic usage and device-associated infections, has posed significant challenges to healthcare. This study reports an outbreak of Proteus mirabilis producing NDM-5 and CTX-M-15 β-lactamases in a hospital in Buenos Aires, Argentina, from October 2020 to April 2021. To our knowledge, this represents the first documented outbreak of NDM-5-producing P. mirabilis in the country. Methods: A total of 82 isolates were recovered from 40 patients, with 41.5% from blood cultures and 18.3% from respiratory and urinary samples, among others. Antimicrobial susceptibility testing, PCR-based methods, and MALDI-TOF MS cluster analysis were conducted. Whole genome sequencing (WGS) was performed to characterize the MLST, resistome and plasmid content. Biofilm formation assays and in vitro rifampicin susceptibility tests were also conducted. Result: Most isolates exhibited resistance to carbapenems, cephalosporins, aminoglycosides, and fluoroquinolones, while retaining susceptibility to aztreonam. Genetic analysis confirmed the co-presence of the bla_NDM-5 and bla_CTX-M-15 genes. Clonal relationships was supported by PCR-based typing and MALDI-TOF MS cluster analysis. WGS revealed a resistome comprising 25 resistance genes, including rmtB and both β-lactamases, as well as the presence of an incomplete IncQ1 replicon associated with multiple resistance determinants. MLST classified this clone as belonging to ST135. Despite the biofilm-forming capacity observed across strains, rifampicin demonstrated potential for disrupting established biofilms at concentrations ≥32 µg/mL in vitro. The MDR profile of the outbreak strain significantly limited therapeutic options. Conclusions: This study highlights the growing threat of NDM-producing P. mirabilis in Argentina. The absence of surveillance cultures from the index case limits insights into the outbreak’s origin. These findings underscore the importance of integrating genomic surveillance into infection control protocols to mitigate the spread of MDR pathogens. Full article

Antimicrobial resistance (AMR) is an emerging global threat that is expanding in many areas of the world. Wastewater-based epidemiology (WBE) is uniquely suited for use in areas of the world where clinical surveillance is limited or logistically slow to identify emerging threats, such as in Sub-Saharan Africa (SSA). Wastewater was analyzed from three urban areas of Kampala, including a local HIV research clinic and two informal settlements. Wastewater extraction was performed using a low-cost, magnetic bead-based protocol that minimizes consumable plastic consumption followed by sequencing on the Oxford Nanopore Technology MinION platform. The majority of the analysis was performed using cloud-based services to identify AMR biomarkers and bacterial pathogens. Assemblies containing AMR pathogens were isolated from all locations. As one example, clinically relevant AMR biomarkers for multiple drug classes were found within Acinetobacter baumannii genomic fragments. This work presents a metagenomic WBE workflow that is compatible with areas of the world without robust water treatment infrastructure. This study was able to identify various bacterial pathogens and AMR biomarkers without shipping water samples internationally or relying on complex concentration methods. Due to the time-dependent nature of wastewater surveillance data, this work involved cross-training researchers in Uganda to collect and analyze wastewater for future efforts in public health development. Full article

Antimicrobial resistance in foodborne pathogens represents a critical global health challenge, with food handlers serving as key contributors in their transmission. This comprehensive review synthesizes evidence on the prevalence, transmission dynamics, and antimicrobial resistance patterns of three major pathogens, Staphylococcus spp., Escherichia coli, and Salmonella spp., among food handlers worldwide. Analysis of studies across diverse geographical regions reveals considerable variation in colonization rates, with Staphylococcus spp. prevalence ranging from 19.5% to 95.0%, Escherichia coli from 2.8% to 89.3%, and Salmonella spp. from 0.07% to 9.1%. Resistance profiles demonstrate alarming trends, including widespread β-lactam resistance and emerging resistance to last-resort antibiotics like carbapenems. Particularly concerning is the high occurrence of multidrug resistant (MDR) strains and extended spectrum β-lactamase (ESBL) producers in low- and middle-income countries. This review identified inadequate handwashing, poor hygiene infrastructure, and asymptomatic carriage as critical factors facilitating the transmission of antimicrobial resistant strains. These findings underscore the urgent need for enhanced surveillance systems, targeted decolonization strategies, improved hygiene protocols, and food handler education to mitigate the spread of resistant pathogens through the food chain. Full article

Vancomycin-resistant Enterococcus faecium represents an emerging threat in healthcare settings. The aim of this study was to investigate biomolecular characteristics of 31 E. faecium isolates from patients in two hospitals of Molise region, central Italy. Particularly, antimicrobial resistance profiles and prevalence of resistance and virulence genes were analyzed, as well as the clonal relationships and sequence types (STs). Antimicrobial susceptibility and genes associated with resistance and virulence were evaluated using automated system and PCR assays, respectively. SmaI-based pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing were performed following standardized protocols. All strains exhibited resistance to vancomycin and teicoplanin, and high rates were detected for other antibiotics, except for linezolid. PFGE identified 18 clusters and 26 pulsotypes (Simpson’s index, 0.98). ST80, ST1478, and ST2164 were identified, with ST80 as the most frequent (77.4%). The resistance genes vanA, aac(6′)-Ie-aph(2″)-Ia, aph(3′)-IIIa, and ermB were detected in 90.3%, 93.6%, 93.6%, and 90.3% of the strains, respectively, while the esp gene was prevalent (61.3%) amongst virulence genes. The study findings highlight the predominance of multidrug-resistant clones and virulence determinants among E. faecium strains circulating in the regional hospitals, reinforcing the urgency of implementing targeted molecular surveillance and robust antimicrobial stewardship strategies to contain their spread. Full article

While the application of antibiotics in livestock production has undeniably propelled the rapid growth of animal husbandry, the escalating crisis of antimicrobial resistance stemming from antibiotic use poses significant threats to global public health and sustainable agricultural development. To address this critical challenge, multifaceted strategies have been implemented through coordinated policy interventions and scientific innovations. This review systematically examines two pivotal dimensions: (1) evolving regulatory frameworks governing antibiotic usage and (2) emerging non-antibiotic alternatives, with a particular focus on their implementation mechanisms and technological maturation. The analysis of transnational antibiotic governance encompasses comparative policy evolution in the European Union, the United States, and China. These regulatory paradigms address critical control points including registration management policies, usage monitoring systems, and integrated surveillance programs. Concerning technological alternatives, six categories of antibiotic substitutes are critically evaluated: Chinese herbal formulations, plant-derived essential oils, antimicrobial peptides, microecological agents, acidifiers, and enzyme preparations. These solutions are functionally categorized into prophylactic agents (enhancing disease resilience) and zootechnical additives (optimizing feed efficiency). These antibiotic alternatives demonstrate certain efficacy in alleviating the challenges of antibiotic overuse, yet they still face multiple implementation barriers. Further investigations are warranted to establish standardized efficacy evaluation protocols and conduct technoeconomic feasibility assessments under commercial-scale production conditions. Ultimately, resolving the antibiotic dilemma requires synergistic collaboration between regulatory bodies, pharmaceutical innovators, and academic researchers. This work emphasizes the crucial interplay between evidence-based policymaking and technological advancement in shaping sustainable livestock production systems. Full article

Chlamydia trachomatis (C. trachomatis) remains the most common bacterial sexually transmitted agent worldwide. Although current treatment regimens are highly effective, sporadic reports of reduced antimicrobial susceptibility and treatment failure raises concerns, especially in the context of increasing global antibiotic consumption and the well-documented rise of antimicrobial resistance (AMR) in other sexually transmitted pathogens. A key factor contributing to the continued efficacy of antimicrobials against C. trachomatis is the unique biology of this species, including its obligate intracellular life cycle, reduced genome, and capacity to enter a persistent state. However, this same biology poses significant challenges to antimicrobial susceptibility testing (AST). Different national surveillance studies have consistently demonstrated low rates of resistance, confirming that C. trachomatis remains largely susceptible to first-line therapies. Nonetheless, these efforts are scarce and have also revealed significant variability in testing protocols, limited geographic coverage, as well as a lack of continuous monitoring. Since antibiotic consumption patterns differ between regions, systematic surveillance will become indispensable to detect emerging resistance trends before they translate into widespread clinical failure. This narrative review synthesizes on a molecular basis the current evidence of C. trachomatis resistance and available AST methods, evaluates findings from different national surveillance studies, and underscores the need for standardized, well-funded surveillance strategies to preserve the long-term efficacy of treatment options for chlamydiosis. Full article

The goal of the present study was to analyze Acinetobacter baumannii strains isolated from hospitalized patients in the period of the COVID-19 pandemic by phenotypic and molecular methods and evaluate their antimicrobial resistance patterns and biofilm production. Forty-seven strains were isolated in 2021–2022 from a hospital in Brazil, and were identified by VITEK^®2, MALDI-TOF/MS (VITEK MS^® and MALDI Biotyper^®), and 16S rRNA sequencing. Fourier-transform infrared (FTIR) spectroscopy was applied for typing and antimicrobial susceptibility testing (AST). In addition, biofilm formation and disinfectant tolerance tests were used. All methods accurately identified all the A. baumannii strains. FTIR typing identified 23 different profiles and 11 clusters, as well as differentiated between the strains from patients with and without COVID-19. Most strains exhibited resistance to the drugs tested, 91.5% of the strains were classified as XDR, 6.4% of the strains were MDR and only 1 strain was classified as non-MDR. Over half of the strains (n = 27, 57.4%) produced biofilms on polystyrene. Sodium hypochlorite (1.0%/15 min) was the best option for effective disinfection. Overall, this study will lay the foundation for further research on effective cleaning protocols for the eradication of A. baumannii biofilms, as well as the use of FTIR for pathogen surveillance in healthcare settings. Full article

Avian colibacillosis caused by avian pathogenic Escherichia coli (APEC) strains is a bacterial disease responsible for enormous economic losses in the poultry industry, due to high mortality rates in farms, antibiotic therapy costs, and seizures at slaughterhouses. The aim of this study was to characterize the serogroups and molecular features of extended spectrum β-lactamase (ESBL)-producing APEC isolates recovered from 248 liver samples of 215 broilers and 33 turkeys with colibacillosis lesions in northeast Algeria. For this, microbiological tests were carried out, according to the recommended standards: E. coli isolates were recovered using standard microbiological protocols, and identification was carried out by MALDI-TOF MS. Serogrouping was performed using a rapid agglutination slide and the antisera of three O somatic groups (O1, O2, O78). Antimicrobial susceptibility was determined by the disk diffusion method. PCR assays and sequencing were used to detect antimicrobial resistance genes, integrons, phylogrouping, and MLST. Conjugation experiments were also conducted to determine the transferability of the retrieved ESBL-encoding genes. Overall, 211 (85.1%) APEC isolates were collected (one per positive sample), and 164 (77.7%) of them were typable. The O2 and O1 serogroups were the most detected (46.1% in broiler typable isolates and 61.5% in turkey typable isolates). Seventeen APEC isolates were ESBL-producers and harbored the following genes (number of isolates): bla_CTX-M-1 (14), bla_CTX-M-15 (2), and bla_SHV-12 (1). They belonged to phylogroups D (10 isolates), B1 (6 isolates), and B2 (1 isolate). The MLST of 13 ESBL producers revealed seven STs: ST23, ST38, ST48, ST117, ST131, ST1146, and ST5087. The ESBL-encoding genes were transferred by conjugation among 15 ESBL-producing isolates, and transconjugants acquired either the IncK or IncI1 plasmids. Concerted efforts from all poultry actors are needed to establish surveillance monitoring strategies to mitigate the spread of ESBL-producing isolates implicated in avian colibacillosis. Full article

Background: Vancomycin-resistant enterococci (VRE) rectal colonization represents a critical risk factor for subsequent bloodstream infections (BSIs), posing a serious concern in healthcare settings. This study aims to investigate the association between the presence of VRE in rectal swabs and the occurrence of BSIs, highlighting the challenges of rapid detection and patient care implications in an infectious disease hospital setting. Methods: We performed a retrospective analysis of cultural rectal swab screening and molecular assays (MAs) for VRE detection between January 2020 and December 2023. All adult patients admitted with at least one rectal swab screening performed during hospitalization were included. All blood cultures that yielded VRE were identified, and the first Enterococcus-positive blood sample for each patient with at least one prior rectal swab per year was analyzed. Results: The results showed a 15.4% positivity rate for VRE in cultural screening, predominantly Enterococcus faecium. MA showed a higher prevalence of 49.4%, with a significant discordance between MA rectal swab screening and cultural testing. Patients with VRE intestinal colonization by E. faecium were significantly more likely to develop E. faecium BSI, with a risk ratio of 9.78 (p < 0.001). Conclusions: The study identified a strong correlation between VRE rectal colonization and the risk of developing BSI, emphasizing the need for effective screening and infection control measures. The results support the inclusion of molecular testing in VRE detection protocols and highlight the importance of ongoing surveillance for antimicrobial resistance. Full article

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. Full article