A comprehensive review of resistome profiles in ocular pathogens: Insights into Pseudomonas aeruginosa and emerging resistance trends.

Burn wound infections pose a major challenge in both critical care and surgical settings, owing to the complex interplay of host immune dysfunction, altered pharmacokinetics, surgical wound dynamics, and the high prevalence of multidrug-resistant (MDR) organisms. This review summarizes current evidence on diagnosis, antimicrobial therapy, and multidisciplinary management of burn wound infections, highlighting common pitfalls and strategies to mitigate them. Burn patients display a distinct microbiological profile that evolves over time: Gram-positive cocci initially predominate, whereas nonfermenting Gram-negative bacilli such as Pseudomonas aeruginosa and Acinetobacter baumannii become increasingly prevalent during hospitalization. Differentiating colonization from infection remains a major diagnostic challenge. Although tissue biopsy is the gold standard for confirming wound infection, it is not uniformly implemented across centers. Therefore, a comprehensive clinical and microbiological evaluation involving infectious disease specialists, intensivists, and surgeons is essential for accurate interpretation of wound status. Antimicrobial stewardship interventions, including pharmacokinetic/pharmacodynamic optimization, therapeutic drug monitoring, carbapenem-sparing regimens, shorter antibiotic courses, and avoidance of redundant combination therapies, are key components of burn infection management. New agents, such as β-lactam/β-lactamase inhibitor combinations and novel tetracyclines, show promise against MDR nonfermenting Gram-negative pathogens. A structured, multidisciplinary team offers the most effective framework for improving outcomes in burn wound infections. Optimizing diagnostics, individualizing antimicrobial therapy, and aligning surgical timing with infection control measures are fundamental pillars. Future research should focus on prospective validation of integrated care pathways and on evaluating the real-world effectiveness of novel antimicrobial agents in burn-injured patients.

A novel Queuovirinae subfamily phage targeting Acinetobacter baumannii: Isolation, characterization, and synergistic lysis system.

Efficient hydrazide-mediated total synthesis of Möbius cyclotides from Viola japonica and elucidation of the antibacterial mechanism of Vija 31.

Synergistic promotion of diabetic wound healing by glucose-responsive functional chitosan-based composite nanohydrogels.

Seven days versus extended duration antibiotic therapy for multidrug-resistant gram-negative bacterial infections in critically ill patients: A pooled analysis of the OPTIMISE and REGARD-VAP trials.

Infants who are HIV-exposed uninfected (HEU) are at greater risk of death compared with infants who are HIV-unexposed, particularly in the first 6 months of life. We investigated the causes of death (CoD) of HEU and HIV-unexposed infants using postmortem minimally invasive tissue sampling. This prospective, observational study enrolled decedents less than 6 months of age at a secondary-tertiary level care hospital in Soweto, South Africa. The minimally invasive tissue sampling included needle core-biopsy sampling for histopathology of brain, lung and liver tissue. Microbiologic culture and/or molecular tests were performed on lungs, liver, blood and cerebrospinal fluid. Underlying, immediate and antecedent CoD were determined by a multidisciplinary team of medical experts. The median age (9 [interquartile range 3, 30] vs. 8 [interquartile range 3, 22] days) and sex distribution (female 58.5% vs. 47.9%) were similar between HEU (n = 65) and HIV-unexposed (n = 119) decedents. A larger proportion of HEU decedents (60%, 39/65) compared with HIV-unexposed decedents (44.5%, 53/119; P = 0.045) had preterm birth as an underlying CoD. Among HEU infants compared with HIV-unexposed infants, sepsis was attributed as an immediate or antecedent cause of death in 46.2% (30/65) versus 36.1% (43/119), respectively. Of the 30 HEU infants with sepsis, 76.7% (23/30) were classified as presumed hospital acquired, most commonly associated with Acinetobacter baumannii (56.5% [13/23]) and Klebsiella pneumoniae (13.0% [3/23]). Similarly, among HIV-unexposed infants with sepsis (n = 43), 72.3% (31/43) were classified as presumed hospital acquired, with A. baumannii (38.9% [12/31]) and K. pneumoniae (38.9% [12/31]) as the predominant pathogens. Pneumonia was attributed as an immediate or antecedent cause of death in 32.3% (21/65) of HEU and 36.1% (43/119) of HIV-unexposed infants. Among those with pneumonia, presumed hospital-acquired pneumonia was identified in 47.6% (10/21) of HEU and 72.1% (31/43) of HIV-unexposed infants (P = 0.035), most frequently due to A. baumannii (50.0% [5/10] HEU; 41.9% [13/31] HIV-unexposed) and K. pneumoniae (30.0% [3/10] HEU; 19.4% [6/31] HIV-unexposed). Presumed community-acquired pneumonia was identified in 52.4% (11/21) of HEU and 27.9% (12/43) of HIV-unexposed infants (P = 0.035). The predominant community-acquired pathogens were respiratory syncytial virus (36.4% [4/11] HEU; 25.0% [3/12] HIV-unexposed) and K. pneumoniae (36.4% [4/11] HEU; 8.3% [1/12] HIV-unexposed). Our study highlights preterm birth as an important underlying CoD among HEU and HIV-unexposed decedents. There was a larger proportion of presumed community-acquired pneumonia deaths in HEU compared with HIV-unexposed decedents. Further research is warranted to explore these differences and develop effective preventive strategies.

Background: Acinetobacter baumannii is a major difficulty in clinical settings since these integrons help bacterial populations to quickly acquire and spread resistance genes. Additionally, mutations in target locations and the overexpression of efflux pumps further aid the organism in resisting antibiotics. objective: The purpose of this work is to identify common gene integrons in human clinical isolates. Methodology: The isolation and identification of A. baumannii, biochemical tests, and the Vitek2 system confirm the diagnosis. Using polymerase chain reaction (PCR) technology, genotyping also detects gene integron classes 1, 2, and 3. Results: The results revealed the presence of A. baumannii in 63 out of 200 isolates, accounting for 31.5% of the isolates from various clinical samples. Special isolates with integron-positive (46.67%) were found. Identified Int1 at 36.67%, Int II at 3.33%, and Int III at 8.33%. Furthermore, 1.67% have sheltered both Int I and Int II. In conclusion, the study revealed a notable prevalence of A. baumannii (31.5%) among clinical isolates, with 46.67% harboring integrons. Class 1 was the most frequent (36.67%), followed by Class 3 (8.33%) and Class 2 (3.33%), while 1.67% carried both Class 1 and Class 2. These findings highlight the significant role of integrons in the dissemination of resistance determinants among A. baumannii clinical isolates. One reason is integrons, which are mobile pieces of DNA that can gather resistance gene cassettes and create a resistant type in the bacteria they infect.

Background: Acinetobacter baumannii is a Gram-negative bacterium increasingly associated with both hospital-acquired and community-associated infections. A. baumannii has spread worldwide due to its strong resistance to many antibiotics. One of the key contributors to its resistance against β-lactam antibiotics is the production of β-lactamase enzymes. Objective: This study aimed to utilize multiplex-PCR technology and clonal lineage to determine the source of the outbreak's origin and the pathways through which A. baumannii isolates were transmitted from various hospitals in Diyala, Iraq. Methodology: The study was conducted from September to November 2024. Out of 190 specimens, 46 isolates of A. baumannii were recovered. Identification of isolates was performed using both CHROM agar and the VITEK 2 compact system. Production of β-Lactamase, such as MBLs, ESBLs, and AmpC, was detected using the phenotypic method, and screening for persistence was employed using two main methods: the rapid killing method and the tolerant disc test. Genetically, three genes (ompA, csuE, and blaOXA-51-like) were the targets of two multiplex PCRs used to determine the isolates' lineages. Result: The phenotypic detection of β-Lactamase production indicated that out of 46 A. baumannii isolates, 16 (34.78%) tested positive for MBLs production, 4(8.69%) tested positive for producing ESBL enzymes, and 43 (93.47%) tested positive for producing AmpC. Therefore, screening for persistence was employed, and the results showed that the total number of isolates of A. baumannii that were positive for these tests was 3/46 (6.52%). The clonal lineage was determined using multiplex PCRs; the result showed 66.6% belonged to Group 1, and 8.33% to both Group 2 and Group 3. Conclusion: The study showed a high prevalence of the G1 (66.6%) isolates were the most often found clonal lineage, and G1 accounts for European clone II, which is resistant to a wide range of different antibiotics.

Background: Environmental contamination with multidrug-resistant organisms (MDROs), including carbapenem-resistant Acinetobacter baumannii (CRAB) and multidrug-resistant Pseudomonas aeruginosa (MRPA), remains a major challenge in healthcare facilities. Hypochlorous acid water (HOCl) has emerged as a promising disinfectant owing to its strong antimicrobial activity and favorable safety profile. This study aimed to evaluate the bactericidal efficacy of atomized HOCl against CRAB and MRPA in a hospital room. Methods: An atomization experiment was conducted in a two-bed room. CRAB and MRPA were prepared using drying and non-drying methods, respectively. HOCl (CLFine) at concentration of 40 and 300 ppm was atomized using ultrasonic humidifiers. Bacterial samples were collected at 0, 1, 3, and 5 h after atomization. Viable bacterial counts were determined by culture, and bactericidal efficacy was evaluated. Results: Atomized HOCl exhibited time- and concentration-dependent bactericidal effects against CRAB and MRPA. CRAB and MRPA reached their limits of detection at 3 and 5 h post-atomization at 40 ppm, and at 1 and 3 h at 300 ppm, respectively. Conclusion: Atomized HOCl effectively inactivated CRAB and MRPA in a hospital room within 3–5 h. These findings support the potential application of HOCl atomization as an adjunctive environmental disinfection strategy for controlling MDRO contamination in healthcare facilities.

Polymer type and aging drive the selective enrichment of antibiotic resistance genes and pathogens in microplastics biofilms.

Acinetobacter baumannii is a multidrug-resistant nosocomial pathogen responsible for infections that are often difficult to treat. Here, we show that exposure of A. baumannii to the last-resort antibiotic colistin, which disrupts the outer membrane of Gram-negative bacteria, results in inner membrane permeabilization and depolarization, ultimately inhibiting ATP synthesis. Nevertheless, under these conditions, colistin-resistant mutants are rapidly and frequently selected. In addition, A. baumannii is able to tolerate colistin, most likely due membrane depolarization and ATP depletion, which are hallmarks of antibiotic-tolerant subpopulations. In this context, we investigated whether bacteriocins can potentiate colistin activity. We identified and characterized two bacteriocins that inhibit the growth of multidrug-resistant clinical isolates, albeit at high concentrations. In vitro analyses showed that these small α-helical bacteriocins permeabilize phospholipid vesicles, highlighting their potential to potentiate antibiotics that compromise cell envelope integrity. Importantly, low concentrations of these bacteriocins combined with colistin leads to a substantial reduction in survival. Moreover, bacteriocin-colistin combinations limit the emergence of colistin-resistant mutants and partially restore susceptibility in colistin-resistant strains. These findings highlight the potential of combining bacteriocins and antibiotics to disrupt cell envelope homeostasis and support further evaluation of this strategy in vivo.

Synergy antibacterial effects of lytic phage vB_AbaA_LLY and levofloxacin against KL2 and KL160 Acinetobacter baumannii.

This study investigate the molecular epidemiology and population characteristics of 184 Acinetobacter baumannii clinical isolates collected in Zhejiang (2015-2020), shedding light on the persistence and success of ST208-KL2 lineage. Whole-genome sequencing and bioinformatic analysis characterized the population structure and transmission dynamics of 184 A. baumannii. Plasmid analysis identified the surrounding structures of blaOXA-58 and blaNDM-1 genes. Serum inhibition assays and Galleria mellonella virulence experiments, combined with global epidemiological analysis, explored the persistence and dominance of ST208-KL2. Of the isolates, approximately 78.8% (145/184) exhibited carbapenem resistance, primarily driven by blaOXA-23, blaOXA-72, blaOXA-58, and blaNDM-1. The A. baumannii population was divided into 2 clusters, distinguished by differences in ST types and resistance islands profiles. Cluster2 accounted for 71 department-time transmission events, mainly involving long-term interdepartmental spread, particularly in the rehabilitation medicine department and intensive care unit. Recombination analysis revealed that recombination occurred mainly in capsular locus (KL) regions, prophage regions, and predicted protein regions. Phenotypic experiments found that ST208-KL2 isolates displayed increased virulence and greater resistance to serum inhibition compared to ST208-KL7 isolates. This finding likely explains its persistently higher prevalence throughout the study period, except in 2019. Cluster2 isolates demonstrated significant advantages in ARG prevalence, resistance rates, and transmission capacity. ST208-KL2, with its superior serum resistance and virulence compared to ST208-KL7, has emerged as a dominant lineage with global implications for infection control and public health.

To monitor the trends of carbapenem-resistant gram-negative bacteria to antimicrobial agents in healthcare facilities in major regions of China between 2015 and 2024. Carbapenem-resistant gram-negative isolates from 74 hospitals in the country were tested for antimicrobial susceptibility using an automated method (imported or domestic AST instruments) supplemented by the disc diffusion method. Results were evaluated using the 2024 CLSI breakpoint. A total of 339 513 clinical isolates were collected between 2015 and 2024. Among clinical Enterobacterales isolates, the rate of carbapenem resistance was generally below 13%, except for Klebsiella spp., where it ranged from 20.4% to 21.9%. Most clinical Enterobacterales isolates are highly susceptible to tigecycline, colistin, and polymyxin B, with resistance rates ranging from 0.1% to 15.4%. The detection rate of meropenem-resistant Pseudomonas aeruginosa has decreased over six consecutive years, from 31.4% in 2018 to 21.5% in 2024. The detection rate of meropenem-resistant Acinetobacter baumannii remained modest, from 64.9% in 2015 to 68.3% in 2024. Multidrug-resistant bacteria remain a significant challenge in clinical anti-infective treatment, and the surveillance of bacterial resistance and the rational use of antimicrobial agents need to be further strengthened to combat bacterial resistance.

Antimicrobial resistance (AMR) is a critical global health crisis, responsible for nearly 5 million deaths in 2019 and projected to impose up to $100 trillion in economic costs by 2050. To address this threat, we are developing new antibiotics targeting the methylerythritol phosphate (MEP) pathway in Acinetobacter baumannii and Klebsiella pneumoniae, major nosocomial pathogens. Our efforts focus on 1-deoxy-d-xylulose 5-phosphate reductoisomerase (IspC/DXR), the committed enzyme in MEP-mediated isoprenoid biosynthesis and absent in humans, making it an attractive therapeutic target. Natural products such as fosmidomycin (FOS) and FR900098 (FR) inhibit IspC but exhibit poor bioavailability. To improve drug-like properties, we synthesized FOS analogs and analyzed their structure-activity relationships (SARs) against recombinant Ab- and Kp-IspC, alongside in vitro susceptibility assays. The most potent analogs, α,β-unsaturated compounds 4b and 16b, inhibited Ab-IspC (AbIspC) with IC50 values of 0.047 μM and 0.029 μM, and Kp-IspC (KpIspC) with 0.194 μM and 0.054 μM, respectively. These showed MICs of 64 μg/mL for A. baumannii and 512 μg/mL for K. pneumoniae. A prodrug series (1d-8d) demonstrated enhanced activity, with compound 3d exhibiting MICs from 0.25 to 32 μg/mL against A. baumannii. X-ray crystallography of Ab-IspC with selected analogs (2b, 3b, 4b) at 2.0 Å resolution provides structural insights to guide future IspC inhibitor optimization.

The conflict in Ukraine highlights the significant challenges posed by antimicrobial resistance (AMR) in resource-limited and combat settings. Alarming rates of multidrug-resistant organisms, including carbapenem-resistant organisms causing up to 60% of healthcare-associated infections, have been reported from Ukrainian hospitals during the conflict. This narrative review examines the current landscape and potential application of diagnostic testing and antimicrobial treatments for high-priority MDROs relevant to these settings, specifically carbapenem-resistant Enterobacterales (CRE), carbapenem-resistant Acinetobacter baumannii complex, and carbapenem-resistant Pseudomonas aeruginosa. This narrative review synthesized information from relevant scientific literature and expert knowledge concerning AMR diagnostics and therapeutics. The focus was on evaluating the application and limitations of current and novel strategies for managing CRE, carbapenem-resistant A. baumannii complex, and carbapenem-resistant P. aeruginosa in resource-limited and combat environments, using the ongoing conflict in Ukraine as a key contextual example. We did not employ a systematic literature search protocol. Diagnostic capabilities in resource-limited settings are often constrained, limiting effective AMR surveillance and targeted therapy. Traditional culture and basic antimicrobial susceptibility testing (AST) face challenges; adaptations like direct disk diffusion and deployable molecular tests offer enhanced capability closer to the field. Newer diagnostics like MALDI-TOF and NGS show promise, but face implementation hurdles related to cost, infrastructure, and interpretation. Treatment in resource-limited and combat settings, such as during the conflict in Ukraine, is severely constrained by a complex intersection of logistical and clinical barriers. These obstacles include a lack of regional epidemiology data, as well as significant supply chain issues involving cold chain requirements, drug instability, and the need for sterile compounding. Furthermore, the administration of novel agents against carbapenem-resistant pathogens is often impractical in austere environments due to the necessity for frequent dosing, prolonged infusion times, and reliable intravenous access. The ongoing development of ultra-broad-spectrum oral agents represents a vital advancement that may facilitate rapid treatment initiation far-forward without the burden of cold-chain logistics or complex IV equipment. AMR presents a critical threat in conflict and resource-limited settings, exacerbated by challenges in diagnostics and treatment logistics. Although novel diagnostic technologies and antimicrobial agents provide potential solutions for managing infections caused by resistant organisms, significant barriers to their effective implementation exist. Addressing these obstacles requires targeted research and adaptation of strategies to ensure optimal deployment of diagnostics and therapeutics in austere environments.

Objective: The present study aimed to determine the antimicrobial activity and phytochemicals of different parts of C. gigantea. Material and Methods: The flower, leaf, stem bark, and latex of C. gigantea were extracted using 50%, 70%, and 95% ethanol. Phenolic and flavonoid content were measured using colorimetric assays. The disc diffusion method was used to evaluate antimicrobial activity against a panel of microorganisms.Results: The ethanolic extracts of C. gigantea (2 mg/disc) from the tested parts contained total phenolic and flavonoid contents ranging from 13-38 mg GAE/ g extract and 1-175 mg RTE/ g extract. Extracts from the flower, leaf, and stem bark showed similar inhibitory effects against Pseudomonas aeruginosa TISTR 1467. Additionally, extracts from the flower and leaf demonstrated inhibition zones against Candida tropicalis TISTR 5136. No inhibitory activity was observed against Staphylococcus aureus ATCC 6538, Acinetobacter baumannii ATCC 19606, Candida albicans TISTR 5554, and Candida krusei TISTR 5351 from any of the tested samples. Conclusion: The ethanolic extracts from various parts of C. gigantea contained a high amount of phenolics and flavonoids, and exhibited antimicrobial activity, particularly against P. aeruginosa and C. tropicalis. These findings suggest that C. gigantea may be a promising natural source for further isolation and purification, which could enable the discovery of new antimicrobial agents.

Acinetobacter baumannii is a Gram-negative nosocomial pathogen that is notorious for its rapid development of antibiotic resistance. However, its ecology and evolution outside hospital settings remain poorly defined. Here, we demonstrate that the natural lifestyle of A. baumannii includes soil-dwelling and airborne dissemination, which helps explaining its adaptability and tolerance to desiccation, radiation and antibiotics, and thus its predisposition to establish within hospitals. Starting from white stork nestlings previously discovered as a reservoir, we studied food chains and associated environments and identified soil and decaying plants as habitats. We demonstrate that sterilized plant material is rapidly colonized by airborne A. baumannii. A set of 401 genomes were sequenced and compared to publicly available genomes, revealing numerous links between wildlife isolates and hospital strains, and disclosing intercontinental dispersal. Our pan-genome estimate of the species (~51,000 gene families) more than doubles that of previous studies. Our data further suggest massive radiation of the species early after its emergence, possibly fostered by human activity since the Neolithic. Now, it is possible to study the ecology and evolution of A. baumannii in nature at an unprecedented temporal and spatial resolution and to elucidate the adaptive evolution of environmental bacteria towards multidrug-resistant opportunistic pathogens.

Bloodstream infections (BSIs) are a major cause of morbidity and mortality among burn patients. The microbiological spectrum and resistance patterns of burn-related BSIs are strongly influenced by local antibiotic usage and infection control practices, underlining the need for institution-specific data. This descriptive cross-sectional study was conducted in a tertiary care hospital in India to characterise the microbiological profile and antimicrobial resistance patterns of BSIs in burn patients. Blood cultures from 66 hospitalised burn patients were processed using standard microbiological methods, of which 25 yielded significant growth. Acinetobacter baumannii was the most frequently isolated pathogen, followed by Pseudomonas aeruginosa and Staphylococcus aureus. BSIs were significantly associated with flame burns, deep burns, diabetes mellitus, prolonged hospitalisation, and high levels of antimicrobial resistance, particularly among Gram-negative organisms. These findings emphasise the importance of locally generated antibiograms and targeted antimicrobial stewardship to guide empirical therapy and improve outcomes in burn patients.