Search Results (995)

Introduction: Several Enterobacterales species harboring New Delhi metallo-β-lactamase (NDM-1) have been reported worldwide. Among them is Providencia stuartii (P. stuartii), an emerging pathogen in nosocomial infections. Objective: This study aimed to perform the clinical and genomic characterization of NDM-1-producing P. stuartii isolates recovered from hospitalized patients during the COVID-19 pandemic in Southern Brazil. Materials and Methods: A retrospective observational study was conducted between April and September 2021 at a Brazilian teaching hospital. Fifty P. stuartii isolates were identified, and carbapenem-resistant isolates underwent phenotypic and molecular characterization. Genetic relatedness was assessed by Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), and selected isolates were subjected to whole-genome sequencing using the Illumina NextSeq platform to determine sequence types, resistance genes, virulence determinants, and plasmid content. Statistical analyses were performed using SPSS version 20.0. Results: Among the 50 isolates, 21 (42%) harbored the blaNDM-1 gene. Most isolates were recovered from tracheal aspirates (57.2%), followed by blood (23.8%), urine (9.5%), and skin and soft tissue samples (9.5%). Significant associations were observed between NDM-1-producing isolates and SARS-CoV-2 infection (p = 0.013), central venous catheter use (p = 0.012), mechanical ventilation (p = 0.006), hemodialysis (p = 0.033), previous antimicrobial exposure, and mortality (p = 0.021). Genomic analysis revealed the presence of blaNDM-1, blaOXA-1, and multiple resistance determinants associated with aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and folate pathway inhibitors. ERIC-PCR demonstrated low genetic variability among isolates, suggesting possible clonal dissemination within the hospital environment. Conclusions: This study reports the emergence of NDM-1-producing P. stuartii during the COVID-19 pandemic in a Brazilian teaching hospital. The low genetic variability among isolates and the multidrug-resistant profile highlight the potential for nosocomial dissemination and reinforce the importance of genomic surveillance and infection control strategies. Full article

Background: Carbapenem-resistant K. pneumoniae (CRKP) represents a major challenge in hospitalized patients because of its association with healthcare exposure, restricted antimicrobial options, and adverse clinical outcomes. Microbiological isolation alone does not define invasive disease; therefore, clinical interpretation requires separation of colonization, localized infection, invasive infection, and carbapenem-resistant Enterobacterales (CRE)-associated sepsis. This study evaluated epidemiological features, resistance phenotypes, treatment adequacy, and clinical outcomes among hospitalized adults with K. pneumoniae isolates, using a clinical framework that distinguishes colonization from active infection and invasive disease. Methods: This single-center retrospective observational cohort study included 157 consecutive adults admitted between January and July 2025 to a tertiary-care hospital with at least one microbiologically confirmed K. pneumoniae isolate recovered from clinical specimens and/or CRE surveillance rectal swabs. Isolates were assigned hierarchically to four mutually exclusive phenotypic groups: carbapenem-susceptible K. pneumoniae (CSKP), extended-spectrum beta-lactamase (ESBL)-producing carbapenem-susceptible K. pneumoniae (ESBL), carbapenem-resistant non-carbapenemase-producing K. pneumoniae (CRKP), and carbapenemase-producing K. pneumoniae (CP-KP). A prespecified secondary analysis compared carbapenem-resistant isolates (CRKP + CP-KP) with non-carbapenem-resistant isolates (CSKP + ESBL). Clinical adjudication distinguished colonization-only cases, non-invasive infection, bloodstream infection, device-associated infection, and CRE-associated sepsis; ventilator-associated pneumonia (VAP) was considered when source data allowed reliable attribution. Sepsis was defined according to Sepsis-3 criteria; quick Sequential Organ Failure Assessment (qSOFA) was used only as a bedside screening tool. Statistical tests were selected according to variable type, distribution, and expected cell counts. Results: The cohort comprised 157 unique patients, with a median age of 71 years (interquartile range [IQR], 61–76). Current CRE colonization was documented in 79/154 patients with available colonization status (51.3%). Complete-case in-hospital mortality was higher in the carbapenem-resistant group (CRKP + CP-KP, n = 46) than in the non-carbapenem-resistant group (CSKP + ESBL, n = 111): 11/42 (26.2%) versus 5/108 (4.6%; Fisher exact odds ratio (OR) 7.31, 95% confidence interval (CI) 2.36–22.65; p < 0.001); overall complete-case mortality was 16/150 (10.7%). Multivariable logistic regression for carbapenem resistance (N = 150; five prespecified covariates; events per variable (EPV) = 9.0) identified age 65 years or older (adjusted odds ratio [aOR] 3.78, 95% CI 1.32–10.86), recent hospitalization within 30 days (aOR 2.56, 95% CI 1.16–5.63), and current colonization (aOR 2.96, 95% CI 1.24–7.05) as independent predictors. CRE-associated sepsis was excluded a priori because of definitional circularity with the case definition. Male sex showed a non-significant protective trend (aOR 0.50, 95% CI 0.22–1.12). CRE-associated sepsis showed a strong bivariate association with carbapenem resistance (OR 9.90, 95% CI 3.91–25.09; p < 0.001), and this association is reported descriptively because the variable was excluded from the multivariable model owing to definitional circularity. Model performance was acceptable, with area under the curve (AUC) 0.77, Hosmer–Lemeshow p = 0.95, and Nagelkerke R² = 0.25. Of 99 molecularly characterized isolates, OXA-48-like was detected in 78 (78.8%), NDM in 71 (71.7%), KPC in 6 (6.1%), and NDM + OXA-48-like dual production in 54 (54.5%); VIM and IMP were uniformly negative. Conclusions: In this high-risk hospital cohort, carbapenem resistance in K. pneumoniae was associated with advanced age, recent healthcare exposure, current CRE colonization, and a pronounced unadjusted mortality signal. Interpretation of sepsis and mortality requires explicit separation of colonization from active infection and invasive disease. These findings support intensified CRE surveillance, source-specific clinical interpretation, rapid resistance detection, and risk-adapted empirical antimicrobial strategies in high-risk hospital settings. Full article

Carbapenem-resistant Enterobacterales represent a major global public health concern, and the rapid and reliable detection of carbapenemase production is of critical importance. In this study, real-time PCR was used as the reference method for carbapenemase detection, and the performance of immunochromatographic and phenotypic methods was comparatively evaluated. A total of 96 carbapenem-resistant Enterobacterales isolates were included, and all were identified as carbapenemase producers by the reference method. Diagnostic performance was assessed using positive percent agreement (PPA) and overall percent agreement (OPA); negative percent agreement and negative predictive value could not be calculated due to the absence of negative isolates. The immunochromatographic test showed complete agreement with real-time PCR in detecting carbapenemase production (PPA and OPA: 100%). At the gene level, sensitivity and specificity were 100% for OXA-48 and NDM, while sensitivity for KPC was 91.7%. In the modified carbapenem inactivation method (mCIM), PPA and OPA values were 97.9% due to false-negative results observed in two isolates producing OXA-48 and NDM by the reference method, and its performance was slightly lower than that of the immunochromatographic method. These findings indicate that the immunochromatographic method is a rapid, reliable, and practical option for carbapenemase detection, particularly in OXA-48-endemic intensive care settings where rapid identification is critical for timely infection control and appropriate antimicrobial therapy. Full article

The global dissemination of carbapenem resistance is predominantly facilitated by plasmid-mediated carbapenemase genes, notably blaOXA-48-like genes. A comprehensive understanding of their evolutionary relationships and structural conservation is essential for monitoring their spread and informing therapeutic strategies. This study aimed to investigate the phylogenetic relationships and structural conservation of blaOXA-48-like carbapenemase genes in multiple Gram-negative bacterial species. We analysed blaOXA-48-like carbapenemase sequences obtained from a hospital in Pakistan and compared them with globally reported variants retrieved from GenBank. Carbapenemase gene sequences (blaOXA-48-like, blaNDM, and blaVIM) were analyzed using maximum-likelihood phylogenetics (MEGA11, Tamura–Nei model, 1000 bootstrap replicates). Comparative global sequences were retrieved from GenBank. Structural modeling of blaOXA-48-like genes was performed using SWISS-MODEL Workspace with the template PDB 3HBR, followed by validation using GMQE, QMEANDisCo, and Ramachandran plot analyses. Phylogenetic analysis revealed a tight clustering of blaOXA-48-like genes across A. baumannii, K. pneumoniae, and E. meningoseptica, showing high similarity to globally distributed plasmid-associated sequences. Structural modeling demonstrated strong conservation of the enzyme, with preserved catalytic residues (Ser70, Lys73, Ser118, Trp157, and Tyr211) and minimal structural deviation (RMSD < 0.3 Å). blaOXA-48-like carbapenemases exhibit strong phylogenetic conservation and structural stability across species and regions, consistent with the horizontal dissemination of blaOXA-48-like genes across bacterial hosts. These findings indicate that blaOXA-48-like carbapenemases have high evolutionary stability. 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

Introduction: Stenotrophomonas maltophilia (S. maltophilia) has emerged as an important opportunistic pathogen. It is resistant to most available antibiotics due to its intrinsic resistance, leaving only some antibacterial agents as possible therapeutic options, which is further complicated by acquired mechanisms of antimicrobial resistance. This study aimed to provide a comprehensive genomic characterization of clinical S. maltophilia complex (Smc) isolates, focusing on molecular characterization of its resistance and virulence, since studies tackling this are scarce in Oman. Methods: This study is a prospective cross-sectional study, in which a total of 21 clinical isolates of Smc were collected from different clinical samples and further characterized using Whole Genome Sequencing. Results: Besides S. maltophilia, the isolates included S. hibiscicola, S. pavanii, and S. muris for the first time in Oman. All isolates were found to be susceptible to cefiderocol, levofloxacin, and minocycline. Sequence types (STs) were diverse among the isolates, with more than half of the isolates showing new STs with novel alleles. Additionally, blaOXA-2, sul1, and the recently described aac(6′)-Iap and aph(9)-Ic were detected among the isolates. Moreover, virulence-associated genes (smf-1, pilT, pilQ, gpmA, rmlA, spgM, stmPr1, plcN, clpP, and katE) were highly conserved across all isolates. Mobile genetic elements were detected in most of the isolates (76.20%). Conclusions: The collected isolates showed high ST diversity and showed no specific pattern in terms of antibiotic susceptibility and resistance genes. More studies are needed to establish relationships between the different members of the Smc and the different molecular resistome and virulome. Full article

Background/Objectives: The global spread of carbapenemase-producing Gram-negative bacteria (CP-GNB) represents a major clinical challenge, causing severe hospital-acquired infections with limited treatment options. Accurate and rapid detection is essential for guiding antimicrobial therapy and implementing infection control measures. Lateral flow immunoassays (LFIAs) targeting the five main carbapenemase families are increasingly used in routine diagnostics, and many new commercial assays have recently become available, often without thorough assessment. The continuous evolution of these enzymes under antibiotic pressure requires regular reassessment of assay performance. Methods: In this study, we evaluated the Beright Carba-5 assay (Alltest Biotech, Hangzhou, China) targeting the five main carbapenemases (KPC, NDM, OXA-48-like, IMP, and VIM), on a panel of 77 whole-genome sequenced Gram-negative bacterial (GNB) isolates exhibiting reduced susceptibility to carbapenems. Seventy-three were carbapenemase-producing (CP) GNBs, including six VIM-, 18 OXA-48-, 14 KPC-, 9 NDM-, 8 IMP-, 10 multiple carbapenemase-, and eight non-targeted carbapenemase-producers. Results: The assay was rapid and easy to use, showing 100% (CI: 73.54% to 100%) specificity, with no false positive results. However, overall sensitivity of CP-GNB detection was lower than expected at 63.08% (CI: 50.20% to 74.72%), with numerous false negatives, particularly among IMP and NDM producers, and to a lesser extent, KPC producers. Detection was more reliable for VIM and OXA-48-like variants. Practical limitations, including insufficient buffer supply, reduced the number of tested isolates from the planned 100 to 77. Conclusions: Overall, the Beright assay demonstrated insufficient sensitivity for routine diagnostic use. 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

Multidrug-resistant organisms, particularly carbapenem-resistant Enterobacterales (CRE), represent a major global health threat. In settings with endemic circulation of carbapenem-resistant organisms, early identification of colonised patients before hospital admission may play a critical role in limiting in-hospital spread and guiding infection prevention strategies. We conducted a retrospective monocentric observational study including all patients evaluated for hospital admission in 2025. Patients presenting predefined epidemiological or clinical risk factors underwent risk-based pre-admission screening for CRE. Patient-level deduplication was applied to microbiologically positive records. Among 2694 patients evaluated for hospital admission, 1084 met predefined screening criteria and underwent rectal swab testing. Overall, 191 unique patients were confirmed as carriers of carbapenemase-producing Enterobacterales, corresponding to 17.6% of screened patients and 7.1% of the overall cohort evaluated for admission. KPC was the most prevalent carbapenemase gene (102/191, 53.4%), followed by NDM (57/191, 29.8%) and KPC/NDM co-production (14/191, 7.3%). Less frequent gene profiles included VIM, OXA-48, and combined carbapenemase patterns. In high-endemic healthcare settings, risk-based pre-admission screening may represent a pragmatic component of infection prevention pathways by supporting early identification of patients with probable CRE/CPE carriage. When analysed at the patient level, such programmes can provide useful operational and epidemiological information for admission management and infection control planning. Full article

Background: Colistin- and carbapenem-resistant Acinetobacter baumannii (CRAB) represent a critical threat in intensive care unit (ICU) settings. This study aimed to provide a comprehensive molecular epidemiological characterization of extensively drug-resistant (XDR) A. baumannii clinical isolates from a tertiary-care hospital in Kırşehir, Central Anatolia, a region previously absent from the national surveillance literature. Methods: A total of 43 non-duplicate XDR A. baumannii isolates recovered from ICU patients between November 2021 and December 2023 were included. Antimicrobial susceptibility testing was performed by automated systems and broth microdilution for colistin. Resistance genes, including OXA-type carbapenemases, extended-spectrum β-lactamases (ESBLs), metallo-β-lactamases, plasmid-mediated colistin resistance (mcr-1 to mcr-5), plasmid-mediated quinolone resistance genes (qnr, qepA, oqxAB, aac(6′)-Ib-cr), and class 1 and 2 integrons, were screened by PCR. Integron gene cassettes were characterized by sequencing. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE) using ApaI digestion. Results: All 43 isolates exhibited the XDR phenotype with universal resistance to carbapenems, colistin, fluoroquinolones, aminoglycosides (except amikacin), piperacillin, cephalosporins, and tobramycin. Amikacin susceptibility was retained in 58.1% of isolates. blaOXA-51 was detected in all isolates (100%), and blaOXA-23 was the predominant acquired carbapenemase (90.7%). Notably, blaOXA-48, a carbapenemase typically associated with Enterobacteriaceae, was identified in 3 isolates (7.0%), each belonging to a distinct pulsotype. No blaOXA-24/40, blaOXA-58, or class B metallo-β-lactamase genes were detected. ESBL genes were found in a subset of isolates, with blaCTX-M group 1 being the most prevalent (20.9%). The aac(6′)-Ib-cr gene was detected in 81.4% of isolates, and oqxA/oqxB in 60.5% and 39.5%, respectively. No mcr or classical qnr genes were identified. Class 1 and 2 integrons were detected in 4.7% and 7.0% of isolates, respectively, carrying dfrA12-DUF1010-aadA2 (class 1) and dfrA1-sat-1 (class 2) gene cassettes. PFGE identified 12 pulsotypes among the typeable isolates; PT4 (n = 20, 47.6%) and PT11 (n = 8, 19.0%) were the dominant clonal clusters, together accounting for 65.1% of typeable isolates. Conclusions: This study presents one of the first comprehensive molecular epidemiological analyses of XDR A. baumannii from Central Anatolia. The dominance of OXA-23-carrying clonal lineages, the detection of blaOXA-48 in A. baumannii distributed across three distinct pulsotypes, the high prevalence of aac(6′)-Ib-cr, and the concurrent distribution of resistance determinants across genetically diverse clonal backgrounds indicate that both clonal expansion and possible horizontal gene transfer contribute to resistance dissemination in this setting. These findings underscore the need for systematic molecular surveillance and reinforced infection control strategies in ICU settings, at both the regional and national levels. Full article

Poultry is the main reservoir of Campylobacter spp. and most human cases result from consuming undercooked poultry or handling raw meat. In 2022, a total of 55 samples, including neck skin, cecal contents, and processing waters, were collected at two poultry slaughterhouses in Italy and analysed according to ISO 10272-2:2017 at the Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata laboratories. Overall, 51/55 (92.72%) samples tested positive for Campylobacter. Among the isolates, 64.71% were identified as C. coli, and 35.29% as C. jejuni. Phenotypic and genotypic analysis were performed to assess antimicrobial resistance and virulence characteristics. All C. jejuni isolates and 72.72% of C. coli showed resistance to fluoroquinolones. Resistances to tetracycline and carbapenem were observed in 60.78% and 45.09% of isolates, respectively. Genomic analysis confirmed the presence of the tet(O) gene, conferring tetracycline resistance. In addition, OXA-450 and OXA-466 genes, conferring beta-lactam resistance, were detected in 78.43% and 3.92% of isolates. Virulence-associated genes were detected. Specifically, the ciaB gene was found in 50/51 (98.04%) of isolates, whereas jlpA, cdtA, cdtB, and ctdC genes were exclusively identified in C. jejuni strains. The high prevalence of pathogenic and antimicrobial-resistant Campylobacter strains highlights the need for strengthened control measures along the poultry production chain. 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

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a significant pathogen for both hospital-acquired and community-acquired infections, characterized by its strong epidemic potential and high mortality rate, posing a severe threat to global public health. CRKP spreads widely across the globe through the horizontal transfer of plasmid-mediated resistance genes such as *blaKPC*, *blaNDM*, and *blaOXA-48*. The clinical treatment options for this bacterium are limited, and its resistance has been increasing year by year, urgently necessitating the development of new antimicrobial drugs or alternative strategies. In recent years, the CRISPR-Cas system has shown great potential in the diagnosis and treatment of CRKP, including rapid detection and identification, gene editing, antimicrobial strategies, and resistance inhibition. For instance, CRISPR-Cas12a/13a can be used for the rapid detection and identification of CRKP, while CRISPR-Cas9/Cas3 can target resistance genes to reverse the resistance of strains. With the advancement of delivery and biotechnologies, the CRISPR-Cas system is expected to become an important tool against drug-resistant CRKP. This review focuses on the application of the CRISPR-Cas system in the detection and treatment of CRKP, analyzing its technical advantages, limitations, and future development directions. Full article

Background/Objectives: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is of great concern because of the difficulties encountered in the management of infections it may cause. This study aims to identify possible difficulties in the management of K. pneumoniae infections in the current context of antibiotic resistance, particularly regarding carbapenem resistance. Methods: This is a retrospective, cross-sectional study that analyses epidemiological, clinical and bacteriological features identified in all patients with CRKP infections/colonization admitted during 2024 in an infectious diseases hospital. Results: Carbapenemase-producing K. pneumoniae isolates were co-harboring NDM+OXA-48 in 55.2% of cases. NDM+OXA-48-producing K. pneumoniae (116 isolates, 55.2%) was correlated with high resistance to aztreonam (100%, p = 0.01), ceftazidime–avibactam (100%, p < 0.01), trimethoprim–sulfamethoxazole (99.1%, p < 0.01), gentamycin (94.8%, p < 0.01), amikacin (93.8%, p < 0.01), colistin (79.8%, p < 0.01). OXA-48-producing K. pneumoniae (29 isolates, 13.8%) was correlated with lower resistance to ceftazidime–avibactam (11.5%, p < 0.01), amikacin (48.1%, p < 0.01), colistin (51.7%, p = 0.01), and gentamycin (65.5%, p < 0.01). We found in vitro synergistic effects of ceftazidime/avibactam + aztreonam for 32/32 CRKP isolates and of colistin + tigecycline for 12/14 CRKP isolates. Higher recurrence of CRKP infections was recorded in patients with urinary tract conditions (RR = 11.58, 95%CI: 1.58–81.91) and upper urinary tract devices (RR = 3.53, 95% CI: 1.72–7.22). In this study, adequate antibiotic treatment, compared to excessive antibiotic treatment in CRKP infections, was associated with shorter treatment duration (p = 0.02) and shorter length of hospitalization (p = 0.04). Conclusions: In our study, CRKP is frequently coharboring NDM+OXA-48, having limited treatment options. Implementing new treatment strategies, testing antibiotic synergies for older antibiotics in order to identify alternative treatment options and avoiding unnecessary carbapenem consumption are essential for decreasing the burden of CRKP infections. Full article

Resistance to 5-fluorouracil (5-FU) and oxaliplatin (OXA) remains an obstacle in colorectal cancer (CRC) therapy, but the upstream mechanisms enabling adaptive survival remain unclear. Angiomotin (AMOT), a Hippo-YAP regulator, is expressed as two major isoforms, p130 and p80, but the contribution of isoform-specific AMOT regulation to chemoresistance is unknown. RNA-seq of OXA-resistant cells identified AMOT as a candidate determinant, and its isoform-specific regulation and functional relevance were then examined in OXA- and 5-FU-resistant CRC sublines. AMOT-p80 was preferentially upregulated, whereas AMOT-p130 remained largely unchanged. Common AMOT pre-mRNA was elevated, whereas p130-specific pre-mRNA was unchanged, consistent with preferential transcriptional activation favoring the p80 isoform. Functionally, AMOT depletion minimally affected basal viability but significantly sensitized resistant cells to 5-FU or OXA, with increased apoptotic responses. AMOT silencing reduced nuclear YAP and lowered c-Myc and Cyclin D1 protein levels, whereas AMOT-p80 re-expression restored nuclear YAP, with recovery of c-Myc/Cyclin D1 levels and drug tolerance. YAP knockdown attenuated these outputs and blunted the additional effect of AMOT depletion. AMOT-p80 overexpression in parental cells increased c-Myc/Cyclin D1 protein levels and enhanced tolerance to 5-FU and OXA. These findings suggest that preferential AMOT-p80 upregulation is linked to YAP-associated chemoresistant phenotypes in CRC cells. Full article