Search Results (598)

Background/Objectives: Antimicrobial resistance (AMR) is a major global health threat that requires the discovery of new antimicrobial agents. Environmental microbiomes from understudied regions represent a valuable source of antimicrobial peptide (AMP) candidates. This study aimed to identify and prioritize AMP candidates from South American genomic and metagenomic datasets and to investigate the antimicrobial potential of bioactive secretomes obtained through bacterial co-culture. Methods: A total of 853 genomes and 360 metagenomes were analyzed using a reproducible genome- and metagenome-mining pipeline combined with machine learning-based AMP prediction. Predicted AMP candidates were further characterized using complementary bioinformatic tools to assess physicochemical, structural, hemolytic, toxicological, anti-inflammatory, and anticancer properties. Selected environmental isolates were subjected to bacterial co-culture, followed by SPE-C18 and HPLC fractionation. Antimicrobial activity, antioxidant activity, hemolysis, minimum inhibitory concentration (MIC), and LC-MS/MS peptidomic analyses were performed on bioactive secretome fractions. Results: Genome and metagenome mining identified diverse AMP candidate sequences associated with bacterial genera including Streptomyces, Bacillus, Burkholderia, and Shewanella. Structural predictions revealed a predominance of α-helical conformations among prioritized candidates. Several secretome fractions obtained from co-cultures displayed antimicrobial activity against Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Active fractions showed no detectable hemolytic activity and exhibited antioxidant activity in DPPH assays. MIC analyses indicated broad-spectrum activity against Escherichia coli ATCC 11229, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii, and MRSA, with an apparent MIC of 10,000 mg/L. LC-MS/MS analysis of bioactive fractions identified peptide sequences by de novo sequencing, including KTESHHK, KRVGPRR, GLFPRLGVSPR, and HHAEHLVHFR. Conclusions: Integrated genome mining, bacterial co-culture activation, and peptidomic analyses provide a useful framework for prioritizing antimicrobial peptide candidates from environmental microbiomes. The identification of peptide-containing bioactive fractions with antimicrobial and antioxidant activities highlights the potential of South American bacterial resources for the discovery of novel antimicrobial compounds. Further purification, peptide synthesis, and biological validation will be required to determine the contribution of individual peptides to the observed activities. Full article

Object: Postoperative infection is a severe complication after pediatric cardiac surgery, which is closely associated with sepsis, multiple organ dysfunction, prolonged mechanical ventilation, extended ICU stay and increased mortality. Conventional microbiological tests (CMT) are limited by low sensitivity, long turnaround time, and poor capacity for detecting viruses and polymicrobial infections. This study aimed to compare the diagnostic efficacy of mNGS with that of CMT, and to explore the impact of polymicrobial infection on clinical outcomes in this high-risk pediatric population. Methods: A retrospective cohort study was conducted on 4889 pediatric patients admitted to the PICU after cardiac surgery from January 2025 to March 2026. A total of 510 patients were diagnosed with postoperative infections, including 879 CMT specimens and 86 mNGS specimens enrolled for analysis. Pathogen detection rates, pathogen spectrum and antimicrobial resistance profiles were compared between the two detection methods. Clinical prognostic indicators including mechanical ventilation duration, PICU length of stay and the requirement for continuous renal replacement therapy (CRRT) were further compared between patients with polymicrobial infection and monomicrobial infection. Results: Respiratory tract infection accounted for 87.8% of all postoperative infections, and Gram-negative bacteria were the predominant pathogens, accounting for 65.9%. The overall pathogen detection rate of mNGS was significantly higher than that of CMT (79.1% vs. 56.5%, p < 0.001). Notably, mNGS exhibited significantly better performance in detecting viruses (37.2% vs. 5.8%, p < 0.001), anaerobic pathogens and polymicrobial infections (38.2% vs. 5.4%, p < 0.001). Patients with polymicrobial infections had significantly longer mechanical ventilation time, longer PICU stay, and higher CRRT utilization rate (all p < 0.05), indicating a poorer clinical prognosis. Gram-negative bacteria showed high resistance to penicillins and early-generation cephalosporins, but remained susceptible to carbapenems and β-lactamase inhibitor combination agents. Gram-positive bacteria showed a high resistance rate to penicillin, while maintaining 100% susceptibility to vancomycin and linezolid. Conclusions: mNGS serves as a more sensitive and comprehensive tool for pathogen detection in children with post-cardiac surgery infections, especially for viral and polymicrobial infections. Polymicrobial infection is an independent risk factor for adverse clinical outcomes. Routine application of mNGS in critically ill children may help guide targeted antimicrobial therapy and improve prognosis. Full article

Background and objectives: Extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae represent an increasing One Health concern because food-producing animals may act as reservoirs of antimicrobial-resistant bacteria with potential transmission to humans. Therefore, this study aimed to assess the prevalence and genomic characteristics of ESBL- and carbapenemase-producing Enterobacteriaceae in livestock and farmers, and to evaluate genomic overlap between animal and human ESBL-producing Escherichia coli to explore potential shared origins and interspecies transmission. Methods: We conducted a cross-sectional study in Osona (Catalonia, Spain), sampling livestock (swine, cattle, poultry, and horses) and farmers. ESBL-, AmpC-, and carbapenemase-producing Enterobacteriaceae were identified and characterized using whole genome sequencing (WGS). Genomic analyses included sequence typing (ST), serotyping, virulence-associated genes, antimicrobial resistance determinants, and plasmid replicon profiling. Results: A total of 945 animals were analysed. ESBL-producing Enterobacteriaceae were predominantly detected in swine, with 63.5% (127/200) of animals testing positive, including four ESBL + AmpC-producing isolates and two carbapenem-resistant Enterobacteriaceae. No ESBL-, AmpC- or carbapenemase-producing isolates were identified in cattle (0/360) or poultry (0/171), and a low prevalence was observed in horses (7.0%, 15/214). A total of 64 farm workers were analysed. ESBL-producing E. coli were detected in 46.7% (7/15) of swine farmers and 8.3% (2/24) of cattle farmers, while no ESBL-producing isolates were found among poultry farmers (0/8) or equine caretakers (0/17). A total of 162 isolates were analyzed by WGS, showing high genetic diversity. Among the 127 Escherichia coli isolates, the most prevalent were ST10 (18/127, 14.2%), followed by ST453 (7/127, 5.5%), ST515 (7/127, 5.5%), and ST10562 (7/127, 5.5%). Virulence-associated gene profiles were heterogeneous, although genes related to stress tolerance and intestinal colonization predominated among ESBL-producing E. coli isolates from swine, including terC (54/127, 42.5%), csgA (41/127, 32.3%), nlpI (41/127, 32.3%), and fimH (39/127, 30.7%). ESBL production among E. coli isolates from swine was primarily mediated by blaCTX-M genes (89/127, 70.1%), with additional contributions from blaSHV (34/127, 26.8%) and blaTEM (40/127, 31.5%). Among swine isolates, IncX1 (100/127, 78.7%), IncFIB(AP001918) (82/127, 64.6%), IncI1-I(Alpha) (69/127, 54.3%), and IncFII (54/127, 42.5%) were the most frequently detected plasmid replicons. Two carbapenem-resistant isolates carrying blaOXA-48 were identified in swine, including E. coli ST58 and K. oxytoca ST145, both associated with IncL plasmids. Conclusions: Swine appear to constitute the primary reservoir of ESBL-producing E. coli. The genomic relatedness observed between animal and human isolates supports shared exposure to a common ecological pool of multidrug-resistant bacteria. The identification of blaOXA-48-producing Enterobacterales associated with IncL plasmids further highlights the public health relevance of livestock-associated antimicrobial resistance. However, the cross-sectional design precludes inference of transmission pathways or transmission directionality. Longitudinal studies are needed to elucidate the dynamics of interspecies transmission. Full article

Background: Healthcare-associated bloodstream infections remain a significant cause of morbidity and mortality in hospitalized children, particularly in intensive care settings. Carbapenem-resistant Gram-negative bacterial (CR-GNB) bloodstream infections and fungemia may present with overlapping clinical features. This can complicate empirical treatment decisions in resource-limited settings. This study evaluated baseline clinical and laboratory characteristics associated with CR-GNB bloodstream infections and fungemia among high-risk pediatric patients. Methods: This retrospective observational cohort study included pediatric patients aged 0–18 years who were evaluated at the time of clinical deterioration and blood culture collection for suspected healthcare-associated bloodstream infection before empirical antifungal therapy initiation for the index episode. Patients who subsequently received empirical antifungal therapy between May 2023 and September 2025 were retrospectively screened. Of the 240 screened patients, 103 met the inclusion criteria and were classified into CR-GNB (n = 56) and fungemia (n = 47) groups based on blood culture results. Clinical, laboratory, and microbiological data were analyzed using univariate and multivariable statistical methods. Results: Observed 90-day all-cause mortality was higher in the CR-GNB group than in the fungemia group (50.0% vs. 29.8%, p = 0.038). Central venous catheter use was more frequent (91.1% vs. 48.9%, p = 0.006), and platelet counts were lower (median: 120 × 10⁹/L vs. 259 × 10⁹/L, p = 0.011) in patients with CR-GNB bloodstream infections. In multivariable analysis, thrombocytopenia (OR: 4.22, 95% CI: 1.35–13.17; p = 0.013) and central venous catheter use (OR: 5.53, 95%: CI 1.89–16.26; p = 0.002) were independently associated with CR-GNB bloodstream infections. The model showed moderate discrimination (AUC = 0.786). Conclusion: In this selected high-risk cohort, thrombocytopenia and central venous catheter use were associated with CR-GNB bloodstream infections. Observed mortality was higher in the CR-GNB group, but this finding should be interpreted with caution as adjusted mortality analysis and standardized severity assessment were not performed. These findings are hypothesis-generating and require validation in larger prospective studies before guiding empirical treatment decisions. Full article

Multidrug-resistant (MDR) pathogens present a significant threat to hematopoietic stem cell transplant (HSCT) recipients; despite their critical implications, regional data on their infection patterns remain scarce. This study aimed to characterize the incidence, pathogen and antimicrobial resistance distribution of clinically confirmed bacterial infections among HSCT recipients. A retrospective analysis was conducted at King Hussein Cancer Center, Jordan (2018–2022). MDR pathogens were defined per CDC criteria. During the study period, 1157 HSCT procedures were performed. A total of 327 patients developed clinically documented bacterial infections, yielding an overall cumulative incidence of 28.3%, with a higher burden in the pediatric cohort (34.7%), including exclusive identification of Klebsiella oxytoca in pediatrics (2.3%). Gram-negative bacteria dominated, with Escherichia coli (50.5%) and Klebsiella pneumoniae (22.0%) being most common. Extended-spectrum beta-lactamase (ESBL) production was the dominant resistance mechanism (71.3%), followed by carbapenem-resistant Enterobacteriaceae (CRE; 14.1%), methicillin-resistant Staphylococcus aureus (MRSA; 8.6%), and carbapenem-resistant Pseudomonas aeruginosa (CRPA; 7.0%). The urogenital (39.1%) and bloodstream (31.2%) were the most infected sites. Significant site-specific associations were noted for ESBL production, MDR-Acinetobacter baumannii (p < 0.001) and MRSA (p = 0.007). Temporal analysis revealed a convergent MDR peak in 2021. Our findings offer critical insights into MDR pathogen incidence in HSCT recipients in the Middle East, informing improved infection management and intensified antimicrobial stewardship in this high-risk population. Full article

Background: The coronavirus disease 2019 (COVID-19) pandemic coincided with substantial changes in healthcare delivery and antimicrobial resistance (AMR) patterns worldwide, particularly in intensive care units (ICUs), where invasive procedures and broad-spectrum antibiotics are commonly used. Data from Türkiye remains limited. Methods: This retrospective observational study evaluated bacterial and fungal isolates from adult ICU patients at a tertiary hospital from 2016 to 2025. Microorganisms were identified, and antimicrobial susceptibility testing was performed using standardized methods. Resistance patterns were compared between the pre-pandemic (January 2016–February 2020) and post-pandemic (March 2020–May 2025) periods. Results: A total of 2666 patients and 5433 isolates were analyzed. Gram-negative pathogens showed marked increases in resistance: carbapenem and colistin resistance in Klebsiella pneumoniae were significantly higher in the post-pandemic period (69.6% vs. 44.4% and 60.5% vs. 22.5%, respectively; p < 0.001). Resistance rates to multiple antimicrobial agents also increased in Acinetobacter baumannii and Pseudomonas aeruginosa (p < 0.05). Among Gram-positive bacteria, vancomycin-resistant Enterococcus faecium increased from 10% to 47.1%. Candida auris emerged only in the post-pandemic period, showing high resistance to fluconazole (75%) and amphotericin B (36.7%). Conclusions: Significant differences in AMR patterns were observed between the pre- and post-pandemic periods in this ICU population. Higher resistance rates were observed among several clinically important bacterial pathogens, and Candida auris emerged exclusively during the post-pandemic period. Given the study’s observational design, these findings should be interpreted as temporal associations rather than evidence of a causal effect of the COVID-19 pandemic. Continued antimicrobial stewardship and infection-control measures remain essential to address the growing burden of AMR. Full article

To improve clinical decision-making about Carbapenem-resistant Gram-negative bacteria (CR-GNB) infections and halt the spread of resistant microbes, quicker and less expensive diagnostic techniques are required. Thus, the purpose of this study was to thoroughly evaluate the diagnostic efficiency (sensitivity, specificity, and concordance) of direct-from-specimen multiplex lateral flow immunoassay (LFIA) across diverse raw clinical specimens and pathogen types from critically sick patients. A total of 300 non-duplicate samples were tested to detect CR-GNB. Five major Carbapenemase genes were detected directly from the specimen using carbapenem-resistant K.N.I.V.O. detection K-Set and from culture using culture-enhanced multiplex PCR. Turnaround time (TAT) of each method was calculated. The direct LFIA revealed 100% specificity for NDM, KPC, and IMP enzymes in all tested clinical matrices (blood, urine, and respiratory samples). The study demonstrated 100% sensitivity and specificity with perfect categorical agreement (κ = 1.000) for the blaKPC in the Klebsiella pneumoniae and for blaOXA-48 and blaIMP in the Acinetobacter baumannii; however, sensitivity of blaVIM was significantly diminished across all isolates and samples. TAT decreased significantly (p < 0.001) from 30 to 70 h to about 50 min. The tested direct LFIA facilitates the prompt enhancement of lifesaving tailored antibiotic treatment for severe illnesses. Full article

Carbapenem-resistant Acinetobacter baumannii (CRAB) is considered a persistent clinical problem characterized by high mortality and restricted therapeutic options. The current antimicrobial regimen focuses on active bacteria without taking into account physiological states that influence the treatment response. Biofilm formation, metabolic changes, efflux activity, and membrane remodeling reduce antibiotic activity at infection sites and help bacteria survive despite in vitro susceptibility. Clinical performance is also compromised by inadequate tissue penetration, toxicity, and inconsistent pharmacokinetics, which reduce the ability to maintain effective antimicrobial activity at the target site. Therefore, a new strategy is needed that considers how bacteria behave during infection. Nanotherapeutic systems can optimize antimicrobial delivery by changing drug distribution and enabling sustained antimicrobial release within infected tissues. These properties can improve antimicrobial distribution within biofilms and structurally restricted infection sites. This review proposes a phenotype-guided approach linking dominant bacterial phenotypes with targeted nanotherapeutic intervention. Advances in nanoscale diagnostics and computational analysis allow earlier identification and more precise characterization of resistance features, so treatment decisions reflect the current state of infection. When integrated with nanotechnology, this information supports treatment approaches that adapt to changes in bacterial behavior over time. Extending this concept to host-directed and microbiome-informed interventions provides additional control by addressing factors that sustain infection beyond the pathogen. These elements create an integrated system that connects detection, analysis, and treatment, allowing therapy to match the biological conditions of infection for more precise CRAB management. Full article

Background: Pneumonia is a common cause of hospitalization and a significant contributor to worldwide morbidity and mortality. Effective definitive antimicrobial therapy for pneumonia relies on accurate identification of bacterial pathogens and their resistance patterns. Therefore, this study aims to evaluate the distribution bacterial pathogens and their antimicrobial resistance patterns, as well as clinical factors associated with outcomes among hospitalized pneumonia patients. Methods: This retrospective cohort study was conducted at Dr. Hasan Sadikin General Hospital, Indonesia, and included adult patients hospitalized with pneumonia between January and December 2024. Clinical, demographic, microbiological, and outcome data were extracted from electronic medical records and the laboratory system. Bacterial distribution, antimicrobial patterns, and clinical outcomes were analyzed descriptively and compared across pneumonia types. Multivariable regression analyses were performed to identify factors associated with in-hospital mortality and length of hospital stay. Results: A total of 662 hospitalized pneumonia patients were included with Gram-negative bacteria (i.e., Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa) identified as the most common pathogens. Carbapenem-resistant Acinetobacter baumannii (CR-Ab) and Klebsiella pneumoniae (CR-Kp) were the most frequently identified resistant pathogens, particularly in hospital-acquired (HAP) and ventilator-associated pneumonia (VAP). HAP and VAP were independently associated with higher in-hospital mortality and longer hospital stay compared to community-acquired pneumonia (CAP). In addition, CR-Ab and difficult-to-treat Pseudomonas aeruginosa (DTR-Psa) were associated with prolonged hospitalization. Conclusions: Type of pneumonia, bacterial pathogens and resistance patterns were associated with in-hospital mortality and length of hospital stay. These findings highlight the importance of ongoing microbiological surveillance, antimicrobial stewardship, and infection prevention strategies to optimize pneumonia management and clinical outcomes. Full article

Background/Objectives: Given the ongoing threat of antimicrobial resistance, the identification and characterization of multidrug-resistant isolates are essential. An increase in antimicrobial-resistant bacteria has been reported in Romania, but national data are still scarce. This study aimed to evaluate beta-lactamase-producing Gram-negative bacteria (GNB) isolated over two years at a Romanian nephrology hospital, while comparing carbapenemase detection phenotypic methods. Methods: Gram-negative bacterial isolates collected between January 2022 and May 2024 that met antimicrobial resistance screening criteria were evaluated. After identification, extensive disk diffusion antibiograms were performed, read, and interpreted, complemented by testing on cloxacillin/oxacillin-supplemented Mueller–Hinton agar. The colistin minimum inhibitory concentration (MIC) was not assessed, and aztreonam–avibactam was not tested for Enterobacterales. For non-fermenter GNB, the colistin MIC was determined. Phenotypic carbapenemase production tests were performed for all strains (BlueCarba Test, CIM, mCIM, zCIM, and rCIM). Carbapenemase detection immunochromatographic tests were performed for a set of strains. Results: Among the 397 evaluated strains, 335 (84.38%) were Enterobacterales and 62 (15.62%) non-fermenter GNB, showing high antimicrobial resistance levels. Of these, 188 (47.35%) were Klebsiella pneumoniae; 139/188 (73.93%) showed carbapenem resistance and carbapenemase production; 49/188 (26.06%) produced two carbapenemases; and 45/188 (23.93%) presented resistance to all tested antimicrobials. MALDI-TOF identified 28 KPC-producing K. pneumoniae strains. Lateral flow assays revealed NDM, VIM, KPC, and OXA-48-like enzymes in 48 of 56 tested Enterobacterales; 12/48 strains produced two carbapenemases. Of the 62 non-fermenter GNB, 33 were Pseudomonas spp. and 20 Acinetobacter baumannii; one Pseudomonas spp. was susceptible only to colistin and seven only to cefiderocol; four A. baumannii were susceptible only to colistin and three only to cefiderocol. Lateral flow assays detected VIM or IMP enzymes in 13/33 Pseudomonas spp. and OXA-23 and/or OXA-40/-58 enzymes in all 20 A. baumannii. Conclusions: Among the evaluated strains, many showed resistance to multiple antimicrobial classes. Furthermore, strains co-producing two carbapenemases were identified. Full article

Introduction: Plazomicin, a novel, semi-synthetic aminoglycoside designed to overcome most aminoglycoside-modifying enzymes (AMEs), represents a therapeutic alternative to traditional aminoglycosides for complicated urinary-tract infections (cUTIs). In this review, we sought to evaluate the available data on drug resistance. Methods: We performed a thorough search across four databases (PubMed, Embase, Scopus, and Web of Science) from their inception to 4 November 2025 to identify relevant studies. The published Clinical and Laboratory Standards Institute (CLSI) antimicrobial susceptibility breakpoints for Enterobacterales were applied. Results: Fifty-five studies, out of a total of 905 records originally identified, were eligible for data extraction and analysis, yielding antimicrobial susceptibility data for 80,159 clinical isolates. The overall resistance of consecutive Enterobacterales isolates to plazomicin was 0–9.4%, and specifically for Escherichia coli and Klebsiella spp. isolates were up to 4.7% and 15.2%, respectively. Among selected isolates with specific resistance mechanisms, the resistance of carbapenem-resistant Enterobacterales (CRE) was 1.8–67.6%, and specifically for carbapenem-resistant E. coli and Klebsiella spp. isolates, 0–10% and 0.3–90%, respectively. Among multi-drug-resistant (MDR) isolates, up to 24.6% of MDR Klebsiella spp. isolates and up to 15% of MDR E. coli isolates were resistant to plazomicin. Among non-fermenting Gram-negative bacteria, the MIC₉₀ values were consistently high. Conclusions: The demonstrated high activity of plazomicin against consecutive Enterobacterales isolates and the considerable, yet variable, activity against selected resistant isolates suggest its consideration as a valuable option in the treatment of complicated urinary-tract infections. Full article

Introduction: Urinary tract infections (UTIs) represent a growing concern in both clinical practice and public health, affecting hospitalized and outpatient populations across all ages and genders. This study aims to evaluate the prevalence of uropathogens and their antimicrobial resistance profiles in male and female patients comparatively at a tertiary urological center. Materials and Methods: A retrospective descriptive analysis was conducted, covering three identical 6-month periods—September 1 to February 28—in three consecutive years from 2023 to 2025. The study included 2270 male patients (2270. 57.06%) and 1708 female patients (1708. 42.94%), all with at least one positive urine culture (>10⁵ CFU/mL). Data on age, gender, bacterial species, and antimicrobial agents were collected and analyzed. Results: A higher prevalence of Gram-negative bacteria was observed compared to Gram-positive bacteria in both male (1752; 77.18% vs. 518; 22.82%) and female (1369; 80.15% vs. 339; 19.85%) groups. The most common microorganisms were Escherichia coli, followed by Klebsiella and Enterococcus. Klebsiella showed high rates of antimicrobial resistance, especially in males, across various antibiotic classes such as amoxicillin-clavulanic acid (60.6% vs. 43.25%), levofloxacin (40.18% vs. 27.91%), aztreonam (37.4% vs. 27.27%), and ceftazidime (36.23% vs. 24.03%). High resistance levels, although not statistically significant, were also noted for trimethoprim/sulfamethoxazole (43.64%) and nitrofurantoin (65.69%). In males, E. coli exhibited higher resistance rates to trimethoprim/sulfamethoxazole (44.65% vs. 32.89%), levofloxacin (43.27% vs. 30.78%), and amoxicillin-clavulanic acid (40.18% vs. 27.19%). Carbapenems remained highly susceptible in both groups. Enterococcus showed similar resistance patterns in both cohorts, primarily resistant to penicillin and levofloxacin. Conclusion: This study highlights higher resistance rates among Gram-negative bacteria in males to commonly used antibiotics such as fluoroquinolones, trimethoprim/sulfamethoxazole, and β-lactams. Resistance patterns in Gram-positive bacteria remained stable across both populations, with high susceptibility to fosfomycin, nitrofurantoin, linezolid, and carbapenems. Differences between sexes emphasize the need for more detailed analysis of local and sex-specific resistance patterns. Full article

Growing resistance to carbapenem antibiotics is a major public health problem as these antibiotics are considered the last line of therapy for infections caused by multidrug-resistant (MDR) Gram-negative bacteria. The rapid emergence and dissemination of carbapenem-resistant bacterial strains are mainly due to horizontal gene transfer (HGT) within or between bacterial cells via the mobilome. The aim of this article is to discuss the role of mobile genetic elements (MGEs) that capture and disseminate resistance determinants of carbapenem antibiotics, as a comprehensive review integrating the combined role of plasmids, transposons and integrons. It attempts to systematically fill the gap by investigating the role of these MGEs in the acquisition, mobilization and dissemination of genes encoding carbapenemases across clinically important bacteria. Various types of plasmids such as IncF and IncH in Klebsiella pneumoniae, IncL/M in Enterobacter cloacae, IncX3 in Escherichia coli and IncA/C₂ in Salmonella enterica carry important genes encoding carbapenemases. The rapid distribution of transposons among bacterial species is one of the main contributing factors in the dissemination of carbapenem-resistant isolates. Transposons including Tn4401 carrying bla_KPC in K. pneumoniae and Tn1721 carrying bla_KPC in E. coli; Tn2006, Tn2007, Tn2008 and Tn2009 carrying bla_OXA-23 in Acinetobacter baumannii; Tn1696 carrying bla_IMP-4 in Pseudomonas aeruginosa; Tn125 carrying bla_NDM in E. coli; and Tn6306 carrying bla_IMI in Raoultella ornithinolytica encode different types of carbapenemases. Integrons mainly belonging to class 1 capture resistance determinants for metallo-carbapenemases such as NDM-, VIM-, SIM- and IMP-type enzymes in P. aeruginosa, A. baumannii, K. pneumoniae and E. coli and can promote the transcription and expression of these determinants. These findings are useful for understanding the genetics of carbapenem resistance and additional knowledge on MGEs may provide avenues for screening of resistance to these antibiotics in clinical settings. Full article

Background/Objectives: Antimicrobial resistance (AMR) is a major global public health threat, particularly in intensive care units (ICUs), where critically ill patients are exposed to high antimicrobial pressure. ESKAPE pathogens play a central role in healthcare-associated infections and are frequently associated with multidrug resistance. This study aimed to evaluate the microbiological profiles and antimicrobial resistance patterns of bacterial isolates from an adult ICU in a tertiary hospital in Brazil. Methods: A retrospective, observational, cross-sectional study was conducted using microbiological culture data from patients admitted during 2024 to the adult intensive care unit of a tertiary hospital in Brazil. Bacterial isolates from clinical specimens were included, and antimicrobial susceptibility testing was performed according to routine laboratory procedures. Descriptive statistics were used to summarize microorganism frequency and antimicrobial resistance rates. Results: A total of 1869 isolates were analyzed, with predominance of Gram-negative bacteria. The most frequent pathogens were Klebsiella pneumoniae (287/1869; 15.33%), Staphylococcus haemolyticus (164/1869; 8.76%), Enterococcus faecalis (144/1869; 7.69%), and Acinetobacter baumannii (135/1869; 7.21%). A high proportion of isolates belonged to the ESKAPE group. Gram-negative bacteria, particularly Klebsiella pneumoniae and Acinetobacter baumannii, showed high resistance to β-lactams, cephalosporins, carbapenems, and quinolones. Among Gram-positive organisms, resistance was high for macrolides, oxacillin, and clindamycin, while glycopeptides and linezolid remained effective. Conclusions: These findings highlight the importance of continuous microbiological surveillance and robust antimicrobial stewardship strategies. The present study adds novel local epidemiological evidence from a Brazilian ICU by integrating species-level distribution, antimicrobial-specific resistance, and resistance patterns by pharmacological class, with particular emphasis on ESKAPE pathogens. Full article

The increasing prevalence of infections caused by multidrug-resistant (MDR) Gram-negative bacteria represents a major global public health challenge. Among hospital-acquired infections (HAIs), ventilator-associated pneumonia (VAP) caused by non-fermenting Gram-negative pathogens, particularly the Acinetobacter baumannii-calcoaceticus complex, it is associated with limited therapeutic options and high mortality. Sulbactam–durlobactam is a novel combination consisting of sulbactam, a β-lactamase inhibitor with intrinsic activity against Acinetobacter spp., and durlobactam, a diazabicyclooctane β-lactamase inhibitor targeting Ambler class A, C, and D enzymes. This review summarizes current evidence on the pharmacological properties, clinical efficacy, and resistance mechanisms associated with this combination. Clinical trials have demonstrated that sulbactam–durlobactam is non-inferior to colistin in the treatment of infections caused by carbapenem-resistant A. baumannii, with a significantly lower risk of nephrotoxicity. The combination is generally well tolerated and represents a promising therapeutic option for difficult-to-treat infections. However, emerging resistance mechanisms, including PBP3 mutations, metallo-β-lactamase production, and efflux pump overexpression, may limit its long-term effectiveness. Further research is required to better understand resistance development and optimize clinical use. Full article