Search Results (1,100)

Background: Ventilator-associated pneumonia (VAP) is a common and serious nosocomial infection in mechanically ventilated preterm infants and is increasingly caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative organisms. Tigecycline, a glycylcycline with broad activity against many such pathogens, is not approved below 18 years of age and carries a boxed warning for excess mortality that is most pronounced in hospital-acquired and ventilator-associated pneumonia. Its role, if any, in preterm infants with VAP is undefined. Objectives: To systematically identify and appraise all human evidence on the efficacy (clinical cure, microbiological eradication, survival) and safety (adverse events, mortality) of tigecycline used to treat VAP or nosocomial pneumonia during mechanical ventilation in preterm infants and neonates. Methods: A PRISMA 2020 structured search of PubMed/MEDLINE, Cochrane CENTRAL, Scopus, trial registries, regulatory documents, Google Scholar and reference lists was designed without language or date restrictions. Eligible reports described tigecycline treatment of pneumonia/VAP in neonates or young infants; pediatric case series and syntheses were retained as contextual evidence. Because only case reports and small non-comparative series were anticipated, a narrative synthesis was pre-specified; JBI tools and GRADE were planned for appraisal and certainty. Results: No randomized controlled trial, controlled observational study, or study dedicated to tigecycline for VAP in preterm infants was identified. Direct evidence meeting the full eligibility criteria (preterm neonate, VAP specifically, separately extractable outcomes) was limited to two case reports of extremely preterm neonates with VAP successfully weaned after tigecycline-based salvage combination therapy. Six further neonatal/young-infant reports initially considered were, on full-text re-review, reclassified as contextual (not index) evidence because they described non-VAP infections (sepsis, or CNS infections such as ventriculitis/meningitis), non-preterm ages, or mixed-infection series without separable VAP data. Reported outcomes were generally favorable in published cases but are subject to severe selection and publication bias; thrombocytopenia, hypofibrinogenemia and hepatic enzyme elevation were the principal adverse signals, against a class-level mortality signal concentrated in VAP. Quantitative pooling was not appropriate. The overall certainty of evidence was very low. Conclusions: There is no direct, credible efficacy or safety evidence supporting tigecycline for VAP in preterm infants. Available data neither establish benefit nor exclude harm. Based on this very-low-certainty evidence and on regulatory/class-level safety data rather than on demonstrated efficacy, tigecycline warrants consideration only as a last-resort, combination salvage option for culture-confirmed pan- or extensively drug-resistant pathogens when no safer alternative exists, with intensive monitoring and, ideally, within a registry or trial. Adequately designed neonatal pharmacokinetic and comparative safety studies are urgently needed. Registration: PROSPERO CRD420261450972 (registered 14 July 2026). Full article

Background/Objectives: Serratia marcescens is an opportunistic pathogen that causes severe hospital-acquired infections, notable for its biofilm formation abilities and development of extensive antibiotic resistance. Here, we aim to evaluate the efficacy of bacteriophages, antibiotics, and antimicrobial peptides (BAP), alone and in combination, against fourteen multidrug-resistant (MDR) S. marcescens isolates sourced from hospitals and other environmental settings. Methods: S. marcescens was grown planktonically or in surface-associated biofilms, and biofilm biomass was measured via changes in absorbance and colony-forming units or live/death staining. Results: Combining bacteriophage with a low-dose cocktail of penicillin–streptomycin, kanamycin, and ciprofloxacin enhanced antimicrobial activity compared with antibiotics alone. Across the isolate panel, responses to BAP treatment varied according to determined antibiotic resistance profiles. The highly resistant AR-0517 isolate was selected for detailed mature biofilm analysis, where the BAP treatment reduced biofilm biomass by 97.8% and recoverable bacteria by 99.99%. Microscopy and viability assays further confirmed extensive biofilm disruption and bacterial killing. Conclusions: These findings demonstrate that simultaneous targeting of multiple bacterial pathways can enhance antimicrobial activity against MDR S. marcescens in vitro and support further evaluation of BAP as a potential strategy for biofilm-associated infections. Full article

During the COVID-19 pandemic, healthcare-associated infections (HAIs) showed a significant increase, exacerbated by the prevalence of multidrug-resistant (MDR) organisms. Antibiotic overuse and infection control practices influenced HAI incidence rates, alongside the rising prevalence of resistant pathogens such as methicillin-resistant Staphylococcus aureus. Antibiotic-resistant pathogens causing healthcare-associated infections in COVID-19 patients include—in addition to methicillin-resistant Staphylococcus aureus—metallo-β-lactamase-producing carbapenem-resistant Enterobacteriaceae, carbapenem-resistant Acinetobacter baumannii, extended-spectrum β-lactamase-producing Klebsiella pneumoniae, and vancomycin-resistant enterococci. COVID-19 impacted bacterial healthcare-associated infections in various ways, with an increase in the incidence of metallo-β-lactamase-producing, carbapenem-resistant organisms—a trend already noted prior to the pandemic. Furthermore, the pandemic laid the groundwork for future challenges in HAI management, highlighting the need for rigorous infection prevention and control protocols. Poorer outcomes were observed in hospitalized COVID-19 patients with antibiotic-resistant infections. Although increased infection prevention and control (IPC) measures led to a reduction in certain site-specific hospital-acquired infections, in other contexts, COVID-19 was associated with an increased incidence of bacterial hospital-acquired infections. Further research is needed to determine the cost–benefit ratio of maintaining COVID-19-related infection prevention and control protocols beyond the pandemic in order to reduce the impact of hospital-acquired infections. Furthermore, it is necessary to assess the long-term impact of the high usage of certain broad-spectrum antibiotics during the COVID-19 pandemic. Full article

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) in the environment is crucial for reducing its transmission, particularly in hospitals, nursing homes, and high-contact public areas. Rapid Point-of-Need (PON) tools at healthcare facilities, without involving prolonged bacterial culture in sophisticated laboratories, are needed for environmental surveillance of MRSA. We have developed a gold nanoparticle (AuNP)-based “Swab-and-Stain” assay for rapid and on-site detection of PBP2a-expressing MRSA from environmental surfaces. The assay utilizes anti-PBP2a antibody immobilized on cotton swabs to specifically capture PBP2a-expressing MRSA and anti-MRSA antibody conjugated on AuNPs to detect the captured MRSA on the swabs via sandwiched complex formation. In the presence of PBP2a-expressing MRSA, the swabs were stained in red, as seen with the naked eye. The color intensity of the stain can be quantified by smartphone image analysis for MRSA quantification. Using PBP2a-expressing MRSA samples spiked in real hospital sink and drain matrices, this pilot study demonstrated a “Swab-and-Stain” assay as a proof-of-concept method for detecting MRSA at a concentration as low as 12 CFU/mL. The assay was validated to specifically detect MRSA spiked in real hospital sink and drain matrices. This “Swab-and-Stain” assay provides a rapid, portable, and easy-to-use platform with potential application for PON environmental surveillance of MRSA. Full article

Background/Objectives: Maternal antibodies can inhibit vaccine-specific humoral responses in early life, leaving infants at increased risk for severe disease for vaccine-preventable infections. In the case of SARS-CoV-2, infants under the age of 3 months represented most child hospitalizations, yet there is no approved vaccine for children under the age of 6 months. There is a clear need for effective immunization in early life to prevent infant morbidity and mortality. Here, we established a mouse model to define how maternally derived antibodies shape early-life responses to mRNA vaccination. Methods: Adult female mice were immunized with PBS or 5 mcg of the SARS-CoV-2 mRNA-1273 vaccine via intramuscular injection and paired with a male. Pups from subsequent litters were immunized with PBS or 5 mcg of mRNA-1273 vaccine via intramuscular injection. Peripheral blood and spleens were collected at time points post-immunization. We measured vaccine-elicited anti-Spike IgG in mouse pups exposed or unexposed to vaccine-specific maternal IgG. Results: Spike-specific maternal IgG is detectable at high levels immediately after pup immunization or mock immunization; however, in mock immunized pups, it wanes by three weeks post-pup immunization. Pups born to immunized dams developed Spike specific IgG comparable to pups born to naïve dams. IgG subclass analyses distinguished passively acquired antibodies from vaccine-induced responses. Despite robust binding antibody responses, neutralizing activity against D614G pseudovirus was heterogeneous and did not scale proportionally with IgG titers, showing qualitative differences in early-life humoral immunity. Splenic Spike-specific B cell frequencies and T follicular helper (Tfh) cell responses were detectable in vaccinated pups irrespective of maternal immunization status, with Tfh cell frequencies peaking at day 7 post-immunization in both groups. Conclusions: Using SARS-CoV-2 as a model pathogen, we found that early-life mRNA vaccination can elicit humoral immune responses in the presence of maternal antibodies. Furthermore, the presence of maternal antibody did not inhibit the development of antigen-specific B cells or Tfh cells in the spleen. Our findings support the potential of extending vaccination strategies into early infancy and provide a framework for optimizing mRNA-based vaccine timing and design in the context of maternal immunity. Full article

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major cause of hospital-acquired infections. Conventional phenotyping for carbapenem resistance requires more than 24 h, which delays clinical decisions and increases the risk of outbreaks. This study aims to develop a lateral flow dipstick (LFD) assay that detects loop-mediated isothermal amplification (LAMP) products targeting the bla_OXA-23-like gene, providing results within 1–1.5 h. Primer specificity was evaluated using seven Gram-positive and nine Gram-negative species commonly present in clinical samples, as well as carbapenem-susceptible A. baumannii and CRAB isolates harboring other resistance genes. The assay detected the bla_OXA-23-like gene at concentrations as low as 1.57 pg/µL, demonstrating ~10-fold greater sensitivity than conventional PCR. The gene was present in 224/268 CRAB samples (83.6%) and absent in 100 carbapenem-susceptible A. baumannii samples. Results were fully concordant with PCR, yielding 100% sensitivity and specificity. The method requires no expensive or complex instrumentation. Future studies should validate the assay across multiple hospitals and clinical specimens to confirm its generalizability and clinical utility. Multiplex LAMP with dual LFD readouts could also enable simultaneous detection of additional carbapenem resistance genes, supporting rapid CRAB surveillance and outbreak control. Full article

Background: Antimicrobial resistance is a major global health challenge, with multidrug-resistant organisms (MDROs) emerging faster than new antimicrobial agents are being developed. The epidemiology of MDROs varies substantially across healthcare settings; however, newly established hospitals remain understudied. This study aimed to characterise the epidemiology and temporal trends of MDROs in a newly established tertiary hospital. Methods: A five-year retrospective longitudinal surveillance study was conducted from 2019 to 2023 in a newly established tertiary hospital in Southern China. Clinical isolates were collected from intensive care unit (ICU) and non-ICU wards. Nine major MDROs were investigated, including extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) and Escherichia coli (ESBL-ECO); carbapenem-resistant Klebsiella pneumoniae (CRKP), Escherichia coli (CRECO), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA); methicillin-resistant Staphylococcus aureus (MRSA); and vancomycin-resistant Enterococcus faecium (VREfm) and Enterococcus faecalis (VREfa). Results: A total of 1533 MDRO isolates were identified during the study period. The predominant pathogens were ESBL-ECO (48.1%), ESBL-KP (16.4%), MRSA (11.4%), and CRPA (11.1%). Most isolates were recovered from non-ICU wards (85.4%), and more than half (51.5%) were community-onset. Isolation rates of ESBL-ECO, CRECO, CRAB, and CRPA were significantly higher in the ICU than in non-ICU wards (all p < 0.05). The incidence density rate of hospital-acquired infections caused by ESBL-KP, CRAB, and CRPA was also significantly higher in the ICU (all p < 0.05). Longitudinal analysis revealed divergent trends among MDROs. While most MDRO isolation rates remained below provincial and national benchmark levels, CRKP and CRAB showed significant increasing trends. CRPA exhibited a distinct pattern, increasing rapidly during the early years after hospital opening, exceeding both provincial and national benchmarks by the second year and remaining elevated thereafter. Conclusions: MDRO epidemiology during the first five complete calendar years after hospital opening was characterised by a predominance of ESBL-ECO, ESBL-KP, MRSA, and CRPA, together with substantial non-ICU and community-onset burdens and heterogeneous temporal patterns across organisms. CRPA increased rapidly and remained above the available external benchmark thereafter. These findings highlight the need for hospital-wide, organism-specific MDRO surveillance, while maintaining intensified infection prevention and control in ICUs and continued vigilance for carbapenem-resistant pathogens, particularly CRPA. Full article

Background: Precision diagnostics are more and more important in intensive care units (ICUs), where rapid identification of infectious agents and antimicrobial resistance determinants is crucial for timely and appropriate treatment. Conventional microbiological methods are frequently limited by long turnaround times and reduced sensitivity, which may delay appropriate treatment. Nanopore sequencing allows rapid, direct, and long-read sequencing of DNA/RNA molecules without the need for amplification, avoiding biases introduced by NGS during amplification and library preparation and generating data in real time. Objectives: This narrative review aims to summarize current knowledge of nanopore technology in the ICU, discuss nanopore principles and current clinical applications in intensive care medicine, highlight its advantages and limitations, and explore future perspectives for integrating nanopore-based diagnostics into precision critical care. Methods: A literature search was performed using PubMed and Web of Science. The literature search was conducted with no lower restriction, covering English-language publications. Results: Nanopore sequencing enables real-time, long-read, single-molecule analysis of native nucleic acid molecules, rapid pathogen identification, antimicrobial resistance profiling, metagenomic analysis, and direct sequencing without amplification. Recent studies have proved the clinical utility of nanopore sequencing in critically ill patients with sepsis, bloodstream infections, hospital-acquired pneumonia, ventilator-associated pneumonia, and fungal and viral infections. Its portability, rapid turnaround time, and potential for point-of-care implementation make it particularly attractive for ICU settings. Conclusions: Nanopore sequencing technology represents a promising molecular diagnostic tool, but wider clinical implementation warrants further larger studies with clinical outcome endpoints, standardized bioinformatic pipelines, and clearer validation pathways. Full article

Acute respiratory distress syndrome (ARDS) represents a major cause of morbidity and mortality in critically ill patients and is most frequently triggered by severe respiratory infections, including nosocomial pneumonia. Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) are highly prevalent in intensive care units and share overlapping pathophysiological mechanisms with ARDS. Despite this close interrelationship, the proportion of patients with nosocomial pneumonia who subsequently develop ARDS remains poorly defined, underscoring the need to identify potential predisposing factors and improve early recognition of patients at risk. While the development of pneumonia in patients with an established diagnosis of ARDS has been extensively investigated, limited data are available on patients who develop ARDS as a complication of HAP/VAP. This narrative review summarizes the limited direct evidence on this topic and discusses potential clinical characteristics, risk factors, and predictive tools, while considering indirect evidence from CAP and broader ARDS populations. Full article

Respiratory and systemic deterioration after intraventricular hemorrhage (IVH) can be difficult to interpret when airway, infectious, neurogenic, and treatment-related factors develop in parallel. A 31-year-old obese man (body mass index 37.56 kg/m²) arrived late at night with right caudate hemorrhage, massive IVH, and acute hydrocephalus. Initial consciousness disturbance was mild and oxygenation was preserved, so close observation was selected. Approximately 6–7 h after arrival, worsening headache, restlessness, and progression of hydrocephalus prompted bilateral external ventricular drainage (EVD). The right EVD output remained poor despite lowering the drainage level. From Day 2 to Day 3, positional snoring, desaturation, tachypnea, fever, and inflammatory marker elevation developed; oxygenation improved with lateral positioning and head elevation, suggesting obesity-related upper-airway compromise with probable sleep-disordered breathing (SDB). On Day 4, recurrent hypoxemia required intubation, and computed tomography (CT) showed entrapment of the right lateral ventricle, prompting endoscopic clot evacuation. Chest CT after the second procedure showed bilateral lower-lobe consolidation consistent with hospital-acquired pneumonia (HAP), and cefazolin was changed to meropenem. Serial glucose measurements showed no persistent hypoglycemia, and early coagulation profiles were not markedly abnormal. However, cultures, arterial blood gas analysis, lactate measurement, echocardiography, abdominal CT, and autopsy were not obtained. Despite treatment, hyperpyrexia, persistent tachypnea, and vasopressor-dependent hypotension progressed, and he died on Day 7. The terminal course was most consistent with infection-associated circulatory collapse and ventilatory failure, while central hyperthermia and other unexcluded causes may have contributed. This case illustrates diagnostic uncertainty rather than a single confirmed terminal diagnosis and emphasizes early systemic evaluation when respiratory, thermal, and circulatory findings evolve after IVH. Full article

Healthcare-associated infections (HAIs) caused by multidrug-resistant Klebsiella spp. represent a critical and escalating global public health threat. Carbapenem-resistant Klebsiella pneumoniae (CRKP) has been designated a critical-priority pathogen by the World Health Organization, and in the 2024 WHO Bacterial Priority Pathogens List, it was the top-ranked pathogen overall. The convergence of carbapenem resistance with hypervirulence in emerging strains has further complicated therapeutic decision-making. This review provides a narrative synthesis of the evidence published between 2020 and 2025 on the prevalence, resistance mechanisms, molecular epidemiology, clinical outcomes, and therapeutic strategies for Klebsiella pneumoniae infections acquired in healthcare settings, with particular attention to the Eastern European and Romanian context. PubMed/MEDLINE, Embase, Web of Science, and the Cochrane Library were searched for relevant publications from January 2020 to June 2025, supplemented by WHO and ECDC surveillance reports. Studies were selected narratively for their relevance to the themes addressed. No new quantitative pooling was undertaken; all summary estimates reported below are cited from the published meta-analyses and surveillance reports that generated them. In the most recent global meta-analysis of hospital-acquired CRKP infection, which pooled 61 studies and 513,307 patients from 14 countries, the global prevalence of CRKP among nosocomial K. pneumoniae infections was 28.69% (95% CI: 26.53–30.86%), with pronounced regional variation from 14.29% in high-income North America to 66.04% in South Asia, and 42.05% in Western Europe. Pooled mortality among patients infected with CRKP has been estimated in a separate meta-analysis at 42.14%, compared with 21.16% among patients infected with carbapenem-susceptible strains, rising to 54.30% in bloodstream infections. Surveillance data place Romania third in Europe for carbapenem resistance among invasive K. pneumoniae isolates, at 50.30%, with a distinctive predominance of NDM plus OXA-48-like co-producers. Ceftazidime-avibactam is recommended for KPC- and OXA-48-producing strains, whereas metallo-beta-lactamase producers require aztreonam-containing combinations. CRKP in HAIs constitutes a global epidemiological emergency characterised by marked regional heterogeneity in carbapenemase distribution, high attributable mortality and rapidly evolving molecular profiles. Locally adapted surveillance, rapid molecular diagnostics, and stewardship programmes are required since empirical therapy cannot be standardised across regions. Full article

Background: Legionella pneumophila is a leading cause of community- and hospital-acquired pneumonia (HAP/CAP), although the clinical and radiological features associated with infection remain incompletely defined. This study aimed to identify clinical, comorbidity-related, and chest computed tomography (CT) features associated with L. pneumophila pneumonia in hospitalized adults with community-acquired pneumonia (CAP). Methods: A retrospective case–control study was conducted at a tertiary-care university hospital in Italy between January 2019 and August 2025. Eighty patients positive for L. pneumophila were compared with 79 controls negative for L. pneumophila. Demographic, clinical, microbiological, and radiological data were collected, and factors independently associated with infection were evaluated using multivariable logistic regression analysis. Results: Patients with L. pneumophila infection exhibited a greater comorbidity burden, particularly heart failure, and were more frequently smokers. Bilateral lung involvement and hilar/mediastinal lymphadenopathy were significantly more common among Legionella-positive patients, whereas overall pulmonary complications and bilateral pleural effusion were more frequently observed in controls. Multivariable analysis identified comorbidity burden as an independent positive predictor of L. pneumophila infection, while intensive care unit admission, oxygen therapy, and pulmonary complication score were independently associated with a lower likelihood of infection. Conclusions: The integration of comorbidity assessment with readily available chest CT findings may help raise clinical suspicion of L. pneumophila pneumonia and support consideration of appropriate diagnostic testing. Full article

Background and Objectives: Urinary tract infections are common in clinical practice, but in hospital settings, especially among older and catheterized patients, the microbial ecology and resistance burden may differ substantially from community-acquired infections. Local surveillance is therefore essential to support appropriate empirical treatment and antimicrobial stewardship. The objective is to describe the microbiological epidemiology of urinary isolates in a tertiary hospital and evaluate temporal trends in antimicrobial resistance among the most frequently isolated microorganisms. Materials and Methods: This retrospective observational study analyzed microbiology laboratory data from Tor Vergata University Hospital, Rome, Italy, collected from January 2022 to June 2025. After WHONET-based deduplication using a 30-day repeat-isolate rule, 5788 deduplicated urinary isolates and 85,888 microorganism–drug associations were included. Descriptive analyses, cumulative antibiograms/antimycograms, and quarterly resistance trends were assessed using univariable and multivariable regression analyses. Results: The population was predominantly elderly, inpatient, and catheter-exposed. Gram-negative organisms predominated, followed by Gram-positive bacteria and fungi. The most frequent isolates were E. coli, K. pneumoniae, E. faecalis, and C. albicans. Although microorganism distribution remained broadly stable over time, resistance increased in several clinically relevant organism–drug combinations, especially among major Enterobacterales. Conclusions: In this high-complexity hospital population, urinary isolates showed a relatively stable microorganism distribution but progressive changes in susceptibility among selected urinary isolates. These findings support setting-specific microbiological surveillance and stewardship-informed empirical treatment strategies. Full article

Background: Pandrug-resistant (PDR) Acinetobacter baumannii represents a major therapeutic challenge in regions where carbapenem-resistant A. baumannii (CRAB) is endemic. Whether the PDR phenotype independently worsens clinical outcomes beyond the effects of disease severity and therapeutic limitations remains uncertain. This study compared the characteristics, management, and outcomes of severe infections caused by PDR and carbapenem-resistant, colistin-susceptible A. baumannii. Methods: We conducted a retrospective analysis of prospectively collected data across 11 tertiary-care hospitals in Greece (February 2022–June 2024). Consecutive adults with bloodstream infection or hospital-acquired/ventilator-associated pneumonia caused by CRAB or PDR A. baumannii were enrolled. The primary outcome was 14-day clinical failure; secondary outcomes included 28-day mortality, microbiological eradication, organ dysfunction, and organ-support-free days. Multivariable logistic and Cox regression analyses, before and after propensity score matching, were performed to adjust for confounding. Results: Among 142 patients, 91 (64%) had PDR and 51 (36%) had carbapenem-resistant, colistin-susceptible infections. Clinical failure occurred in 41% of patients and did not differ significantly between PDR and CRAB infections (39% vs. 45%; p = 0.440). Twenty-eight-day mortality was 33% and 22%, respectively (p = 0.139). After adjustment, the PDR phenotype was not independently associated with clinical failure or mortality. Higher APACHE II score and pneumonia independently predicted clinical failure, whereas sulbactam-containing therapy was associated with lower odds of failure (OR 0.24, 95% CI 0.07–0.79). Older age, higher SOFA score, impaired lactate clearance, and tigecycline-containing therapy independently predicted 28-day mortality. In matched analysis, PDR showed a non-significant upward trend in 28-day mortality (HR 2.36, 95% CI 0.97–5.76; p = 0.059). Conclusions: In severe A. baumannii infections, the PDR phenotype was not an independent determinant of clinical failure or short-term mortality. Patient severity and antimicrobial strategy were major outcome correlates; treatment associations should be interpreted cautiously given the observational design. Full article

Background/Objectives: Infective endocarditis (IE) is a life-threatening cardiovascular infection with in-hospital mortality of 15–30% despite modern therapy. Contemporary IE demonstrates non-random valve involvement: aortic and mitral 35–45%, tricuspid 5–10% (30–50% in intravenous drug users [IVDU]), and pulmonary < 1%. These patterns implicate valve-specific anatomy and hemodynamics as central determinants of susceptibility. This narrative review examines the reported distribution of IE across the aortic, mitral, tricuspid and pulmonary valves and summarises the anatomical, haemodynamic, structural, microbial and patient-related factors associated with valve-specific susceptibility. Methods: A structured narrative review of English-language literature was conducted using PubMed/MEDLINE, Embase, Scopus, and Google Scholar (January 1990–March 2026). Search terms included “infective endocarditis,” “valve anatomy,” “hemodynamics,” “bicuspid aortic valve,” “prosthetic valve endocarditis,” and “transcatheter aortic valve replacement (TAVR) endocarditis.” We included anatomical studies, clinical cohorts, surgical series, imaging research, and international guidelines. Evidence was synthesized narratively using Oxford Centre for Evidence-Based Medicine (CEBM) levels. Results: IE susceptibility follows a biologically coherent gradient determined by the interaction between valve anatomy, hemodynamic stress, endothelial injury, and structural substrate. The aortic valve is most vulnerable because of high shear stress, congenital abnormalities such as bicuspid aortic valve, and direct continuity with the cardiac fibrous skeleton, predisposing to peri-annular extension. Mitral valve IE is largely conditional upon pre-existing structural disease, particularly mitral valve prolapse, rheumatic heart disease, and mitral annular calcification, and is characterized by a high risk of systemic embolization. Tricuspid valve IE reflects the interaction between low-pressure hemodynamics and acquired patient-specific modifiers, including intravenous drug use, cardiovascular implantable electronic devices, and congenital heart disease. Pulmonary valve IE remains uncommon because of favorable native hemodynamics but occurs predominantly in repaired congenital heart disease, right ventricular outflow tract reconstruction, and prosthetic pulmonary valves. Across all valve types, multimodality imaging and anatomical assessment consistently influence complication detection, surgical planning, and long-term surveillance. Conclusions: IE involvement is unevenly distributed among the cardiac valves. Aortic and mitral involvement predominate, tricuspid involvement is strongly influenced by injection drug use and intracardiac devices, and pulmonary-valve IE remains rare and is principally associated with congenital abnormalities or prosthetic material. These patterns highlight the possible contributions of haemodynamic stress, pre-existing structural abnormalities, and age-related valvular changes to the greater susceptibility of left-sided valves. Full article