Search Results (98)

Background and Objectives: Changes in the incidence of healthcare-associated infections (HAIs) during the coronavirus disease 2019 (COVID-19) pandemic and during periods with fewer or more COVID-19 cases have been inconclusively studied. Compared with 2015, in 2019, the abundances of the microorganisms Klebsiella pneumoniae and Enterococcus faecium increased in intensive care units (ICUs) in Taiwan. The trend in the incidence of HAIs in ICUs in Taiwan during the emergence of new infectious diseases is worth studying. Materials and Methods: We surveyed the incidence densities of different types of HAIs, device-associated HAIs, pathogens, and antimicrobial resistance in a dataset from the Taiwan Healthcare-associated Infection and Antimicrobial Resistance Surveillance System from 2015 to 2022. The change in incidence density trends was evaluated via Poisson regression, and the change in proportion trends was checked via the Mantel–Haenszel chi-square test. Results: The incidence of HAIs decreased from 5.7 to 5.17 episodes per 1000 person-days from the pre-COVID-19 period to the post-COVID-19 period. The incidences of healthcare-acquired pneumonia (HAP), device-associated HAIs decreased. However, the incidences of bloodstream infections (BSIs) increased. The percentages of patients with Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii infections significantly decreased. The percentage of patients with methicillin-resistant Staphylococcus aureus (MRSA) infection decreased, but that of patients with carbapenem-resistant K. pneumoniae (CRKP), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa, and vancomycin-resistant Enterococcus faecium infections increased. The antimicrobial consumption related to CRKP increased and MRSA decreased. Conclusions: Overall, HAIs, HAP, and VAP decreased in incidence after the COVID-19 pandemic. These results revealed decreases in MRSA infection incidence under infection control protocols with more antimicrobial use. However, the proportion of CRKP among HAIs increased with broad-spectrum antimicrobial agent use. Based on the recent incidence of HAIs in ICUs, the quality of infection control in medical units can be enhanced to decrease HAI incidence. Full article

Background/Introduction: Carbapenem-resistant Klebsiella pneumoniae (CRKP) bacteremia is a serious public health problem due to its high mortality rate and limited treatment options. This study aimed to identify risk factors associated with ceftazidime–avibactam (CAZ-AVI) resistance in CRKP bacteremia and to evaluate its impact on clinical outcomes. Methods: This retrospective single-center cohort study included adult patients with CRKP bloodstream infections treated at a tertiary hospital in Türkiye between January 2021 and December 2024. Demographic, clinical, and laboratory data were collected, and risk factors for CAZ-AVI resistance and 30-day mortality were analyzed. Results: Among 154 patients, 42.8% had CAZ-AVI-resistant strains. Resistant infections were associated with longer hospital stays and higher Charlson Comorbidity Index (CCI) scores. The resistance rate was lower in patients with intra-abdominal infections, while fluoroquinolone and fosfomycin use was more common in the resistant group. The overall 30-day mortality rate was 57%. Pitt bacteremia score and creatinine levels were identified as independent predictors of mortality. Discussion: CAZ-AVI resistance in CRKP bacteremia appears to develop in patients with prolonged hospitalization and high comorbidity burden. These factors likely increase exposure to resistant microorganisms and antibiotic pressure, complicating treatment outcomes. Conclusions: CAZ-AVI resistance in CRKP bacteremia is associated with specific clinical risk profiles and contributes to high mortality. Identifying high-risk patients and optimizing antimicrobial stewardship are essential to improve prognosis. Full article

Klebsiella pneumoniae is one of the top pathogens causing bloodstream infections (BSIs) worldwide. The rise of carbapenem-resistant K. pneumoniae (CRKP) and multidrug-resistant (MDR) strains is of particular concern as therapeutic options are limited. Analyzing local resistance profiles is essential for the success of antibiotic stewardship strategies. This study aims to explore the resistance profiles of K. pneumoniae strains identified in BSI in a tertiary care hospital over 7 years. Automated systems were used to test antibiotic susceptibility. Results were interpreted according to EUCAST clinical breakpoints. The rate of multidrug resistance (MDR) was 57.6%. The percentage of ESBL producers was 54.5%, and the percentage of carbapenemase producers was 43.2%. Overall resistance rates to other antibiotics were 47.1% to ciprofloxacin, 31.4% to gentamicin, 25.7% to amikacin, 20.9% to colistin, 19.6% to Fosfomycin, and 44.5% to trimethoprim/sulfamethoxazole. The highest resistance to colistin was recorded in 2023 (28%). More than half of the strains in the study were MDR and ESBL producers. K. pneumoniae resistance to colistin has increased during the last 7 years. The rates of carbapenemase-producing bacteria (CPB) are on the rise. The most frequently co-harboring carbapenemases were NDM and OXA-48. Local antibiotic resistance rates are crucial in implementing an effective antibiotic stewardship strategy. Full article

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant therapeutic challenge, particularly when multiple resistance mechanisms, such as metallo-β-lactamases (MBLs) and Klebsiella pneumoniae carbapenemase (KPC), coexist. Case description: We describe a case of a 51-year-old male with a post-sternotomy surgical site infection and concurrent bacteremia caused by a CRKP. Sternal swab and mediastinal liquid culture results highlighted CRKP harboring bla_NDM and bla_KPC genes, while the blood isolate showed bla_CTX and bla_KPC, indicating phenotypic resistance to ceftazidime-avibactam. All the strains exhibited phenotypic susceptibility to meropenem-vaborbactam (MEV), despite having a high minimum inhibitory concentration. Following clinical failure of MEV-based therapy, combination treatment with aztreonam (ATM) and imipenem/cilastatin/relebactam (IMI/REL), plus gentamicin, was initiated. Therapy was well tolerated and resulted in microbiological eradication and full clinical recovery. The patient completed 49 days of ATM and IMI/REL without relapse over a 3-month follow-up period. This is, to the best of our knowledge, the first reported case of IMI/REL being used in combination with ATM. Full article

Background/Objectives: Carbapenem-resistant Klebsiella pneumoniae (CRKP) threatens Intensive Care Units (ICU), particularly in settings where serine (KPC) and metallo-β-lactamases (NDM) co-circulate. The aim of this study was to assess CRKP susceptibility especially to novel β-lactam/β-lactamase inhibitor combinations, characterize the genetic determinants of resistance, and contribute to the understanding of local epidemiology in the ICU of our hospital. Methods: We studied 32 non-duplicate CRKP isolates (30 ICU, 2 wards) collected at Hippokration General Hospital, Thessaloniki (May–Oct 2023). Bacterial identification and Antimicrobial susceptibility testing (AST) were performed by VITEK-2; Minimum inhibitory concentrations (MICs) for ceftazidime/avibactam (CAZ/AVI), meropenem/vaborbactam (MER/VAB), and imipenem/relebactam (IMI/REL) were determined by E-tests. Colistin MICs were performed by broth microdilution. Carbapenemases were screened phenotypically and by immunochromatography and confirmed by multiplex PCR. One bronchial isolate co-harboring bla_NDM and bla_KPC genes underwent WGS. Results: All isolates were carbapenem-resistant and showed extensive resistance to β-lactams and fluoroquinolones. By PCR, 8/32 (25%) carried bla_KPC alone, 8/32 (25.0%) bla_NDM alone, and 16/32 (50%) co-harbored bla_KPC and bla_NDM. KPC-only isolates were generally susceptible in vitro to CAZ/AVI, MER/VAB, and IMI/REL, whereas dual KPC-NDM producers were resistant to all three combinations. Tigecycline showed the highest retained activity; colistin remained active in a minority. WGS of one ST512 (CG258) isolate revealed co-harboring bla_NDM-1 and bla_KPC-3 with additional resistance determinants and plasmid replicons, consistent with high-risk spread. Conclusions: Half of CRKP isolates in this ICU-predominant series co-produced KPC and NDM, severely limiting β-lactam/β-lactamase inhibitor options. These data support routine screening for carbapenemases, strict infection prevention, antimicrobial stewardship, and access to agents active against MBLs. Full article

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a critical global health threat due to its multidrug resistance, primarily driven by carbapenemase production. Rapid and accurate detection of carbapenemases is essential for effective treatment and infection control. This study evaluates the validity of the NG-Test CARBA 5, a rapid immunochromatographic assay, for detecting five major carbapenemases (KPC, NDM, VIM, IMP, OXA-48-like) in clinical CRKp isolates. Methods: Clinical isolates of CRKp were collected from various clinical specimens at the Military Medical Academy in Belgrade, Serbia, between January 2023 and October 2024. Detection of carbapenemases was performed using NG-Test CARBA 5, while PCR served as the reference method. Diagnostic performance was assessed by calculating sensitivity, specificity, and Cohen’s kappa coefficient. Results: Among 312 isolates, OXA-48-like was the most prevalent carbapenemase. NG-Test CARBA 5 showed high sensitivity (98.7%) and specificity (100%) overall, with excellent agreement for NDM (κ = 0.947), OXA-48-like (κ = 0.957), and KPC (κ = 0.978). However, it failed to detect VIM in five PCR-positive isolates, suggesting potential limitations. Conclusions: NG-Test CARBA 5 is a rapid and reliable tool for detecting major carbapenemases in CRKp, though its performance for VIM detection requires further investigation. This assay has the potential to improve clinical diagnostics and strengthen infection control in settings with high antimicrobial resistance. Full article

Carbapenemase-producing Klebsiella pneumoniae (CRKP) is a critical public health threat, particularly in Greece, where high prevalence limits therapeutic options. This retrospective study analyzed 26 CRKP isolates recovered at the General Hospital of Volos between July 2024 and January 2025, aiming to correlate carbapenemase phenotypes with clinical and epidemiological parameters. Demographic, clinical, and microbiological data were extracted from patient records, and isolates underwent phenotypic carbapenemase detection, antimicrobial susceptibility testing, and molecular characterization using real-time PCR; four isolates were further analyzed using whole-genome sequencing. CRKP was detected across multiple hospital departments, notably in the Emergency Department (n = 5) and Intensive Care Unit (n = 6). KPC producers predominated (n = 9), followed by NDM (n = 6), VIM (n = 1), and OXA-48 (n = 6). All VIM- or NDM + VIM-positive cases were associated with mortality. High-risk clones, including ST15, ST11, and ST307, were identified, with one ST15 isolate harboring bla_NDM-1, bla_VIM-1, and chromosomal colistin resistance; this is the first such report in Greece. Colistin and gentamicin were the most active agents in vitro; three isolates were pan-drug-resistant. The findings highlight significant CRKP circulation outside ICUs, the role of horizontal gene transfer in resistance dissemination, and the need to expand screening and rapid diagnostics to non-ICU settings. Enhanced molecular surveillance targeted at infection control and strengthened antimicrobial stewardship programs are essential for limiting the spread of CRKP. Full article

Klebsiella pneumoniae, a member of the Enterobacterales Order, often colonises the gut and causes diverse infections, including bloodstream, urinary, and respiratory infections. The rise in carbapenem-resistant sFtrains, especially those producing enzymes like K. pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Oxacillinase 48 (OXA48), or combinations (NDM+OXA48-like), poses a significant threat across Europe, notably in Romania. These strains spread rapidly via mobile genetic elements, complicating treatment. Methods: A retrospective study of multidrug-resistant (MDR) K. pneumoniae strains isolated from clinical samples collected at an infectious diseases hospital in Romania. Results: We analysed the evolution of carbapenemases and their combinations from 2010 to 2024, with the rising antibiotic consumption, particularly during the COVID-19 pandemic. The prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) rose from 4.9% in 2010 to 41.6% in 2024. There was an overall antibiotic use increase, especially colistin (186%) between 2019–2024. Additionally, we examined the dynamics of antibiotic susceptibility that decreased in 2023–2024 and found that susceptibility of NDM+OXA48-like isolates to colistin was 16.5% and to cefiderocol 58.5%. Conclusions: The rising prevalence of K. pneumoniae strains with complex resistance mechanisms, coupled with a significant reduction in available treatment options, demands a fundamental paradigm shift in the management of these infections. Full article

Background: The global impact of the SARS-CoV-2 pandemic on antimicrobial resistance (AMR) patterns has been significant. In northern Brazil, Carbapenem-resistant Klebsiella pneumoniae (CRKP) are a major concern, with an observed shift from Klebsiella pneumoniae carbapenemase (KPC) to New Delhi metallo-β-lactamase (NDM) during the pandemic. Methods: This cross-sectional study analyzed 775 carbapenem-resistant K. pneumoniae isolates collected from 25 hospitals in the Brazilian Amazon Region (states of Pará and Acre) between 2018 and 2021. The isolates were tested for the presence of carbapenemase genes (bla_KPC, bla_NDM, bla_OXA-48, bla_IMP, bla_VIM, bla_AIM, bla_DIM, bla_GIM and bla_SIM). Results: Of the isolates analyzed, n = 653/775 (84%) were carbapenemase producers, with the most prevalent being bla_KPC n = 446/775 (57.5%) and bla_NDM n = 243/775 (31.4%). A significant increase in NDM producers was observed during the pandemic, rising from n = 1/250 (8.4%) pre-pandemic to n = 222/525 (42.3%) during the pandemic, while KPC producers declined from n = 172/250 (68.8%) to n = 274/525 (52.2%) (p < 0.001). Adult intensive care units (ICUs) were the primary source of isolates n = 357/775 (46%), with a notable increase in tracheal secretion and surveillance swab samples during the pandemic. Regression analysis confirmed a strong upward trend in the prevalence of bla_NDM (R² = 0.778). Conclusions: The shift from KPC to NDM producers in northern Brazil highlights an evolving AMR landscape, partly driven by the pandemic. Strengthened infection control measures, antimicrobial stewardship and continuous surveillance are essential to mitigate the spread of NDM-producing K. pneumoniae in settings with limited resources. Full article

Background: The emergence and spread of the tigecycline resistance gene tet(A)-v1 in carbapenem-resistant Klebsiella pneumoniae (CRKP) poses significant public health challenges. However, the prevalence of tet(A)-v1-positive CRKP, especially in pediatric patients, remains poorly understood. This study aims to address the gap by performing an in-depth analysis of isolates collected from a children’s hospital in China. Methods: A 4-year retrospective study was conducted in the children’s hospital in Suzhou, China. Non-duplicated specimens were obtained from pediatric patients, and antimicrobial susceptibility profiles were assessed. Whole-genome sequencing and bioinformatics analyses were conducted to characterize the genetic background, antimicrobial resistance determinants, hypervirulence-associated genes, diversity of tet(A)-v1-carrying plasmids, the genetic environment of tet(A)-v1, and the potential for clonal transmission. Conjugative transferability of tet(A)-v1-carrying plasmids was also evaluated via conjugation assays. Results: Of the 73 tet(A)-v1-positive CRKP isolates from pediatric patients, 10.96% were non-susceptible to tigecycline. These isolates exhibited high genetic diversity, spanning across 13 STs (sequence types), with ST17 being predominant. Three carbapenemases were identified, with IMP being the most common. Isolates from diverse backgrounds, such as ST17, ST20, ST323, ST792, and ST3157, demonstrated evidence of clonal transmission. The tet(A)-v1 gene was located on 14 distinct plasmids across seven replicon types, with IncFIA/IncHI1 and IncFII being most commonly detected. All tet(A)-v1-carrying plasmids were multidrug-resistant, and 68.49% were conjugatively transferable, indicating a high potential for horizontal transfer. Four genetic contexts bordering tet(A)-v1 were identified, which points to active clonal dissemination. Conclusions: Although limited to a single hospital, this study represents one of the first in-depth investigations of tet(A)-v1-positive CRKP in pediatric patients, providing valuable insights into the prevalence and spread of tet(A)-v1 in this vulnerable group. These findings emphasize the urgent need for enhanced surveillance and infection control measures to curb the spread of tet(A)-v1-positive CRKP in pediatric healthcare environments, offering critical insights to mitigate its public health impact. Full article

Background/Objectives: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an urgent public health threat due to its rapid dissemination and resistance to last-line antibiotics. Cefiderocol (FDC), a novel siderophore cephalosporin, targets resistant Gram-negative pathogens by exploiting bacterial iron uptake mechanisms. However, resistance to FDC is emerging among Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae strains. This study characterizes a spontaneous FDC-resistant subpopulation (IHC216) derived from a KPC-producing strain (KPNMA216) using comprehensive genomic, transcriptional, and phenotypic analyses. Methods: Given the whole-genome sequencing results, where mutations were identified in genes involved in transcriptional regulation and membrane permeability (ompC) among others, in the present work we further explore their potential implications and conduct a more detailed analysis of the IHC216 genome. A qRT-PCR analysis highlighted significant downregulation of classical siderophore-mediated iron acquisition systems (fepA, cirA, iroN) and upregulation of alternative iron uptake pathways (iucA, fiU), reflecting a switch in iron acquisition strategies. Results: A notable downregulation of bla_KPC-163 correlated with restored susceptibility to carbapenems, indicating collateral susceptibility. Altered expressions of pbp2 and pbp3 implicated adaptive changes in cell wall synthesis, potentially affecting FDC resistance mechanisms. Furthermore, enhanced oxidative stress responses via upregulated sodC expression and increased capsule production were observed. Conclusions: These findings underscore the complex interplay of genetic and transcriptional adaptations underlying FDC resistance, highlighting potential therapeutic vulnerabilities. Full article

Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) is eroding therapeutic options for urinary tract infections. We isolated a multidrug-resistant strain from the urine of a chronically bacteriuric patient and confirmed its identity by Vitek-2 and MALDI-TOF MS. Initial disk-diffusion profiling against 48 antibiotics revealed susceptibility to only 5 agents. One month later, repeat testing showed that tetracycline alone remained active, highlighting the strain’s rapidly evolving resistome. Given the scarcity of drug options, we performed an “aromatogram” with seven pure essential oils, propolis, and two commercial phytotherapeutic blends. Biomicin Forte^® produced a 30 mm bactericidal halo, while thyme, tea tree, laurel, and palmarosa oils yielded clear inhibition zones of 11–22 mm. These in vitro data demonstrate that carefully selected plant-derived products can target CR-Kp where conventional antibiotics fail. Integrating aromatogram results into One Health’s stewardship plans may therefore help preserve last-line antibiotics and provide adjunctive options for persistent urinary infections. Full article

Introduction: Carbapenem-resistant Klebsiella pneumoniae (CRKP) represents a critical public health threat due to its rapid nosocomial dissemination, limited therapeutic options, and elevated mortality rates. This study aimed to characterize the epidemiology, carbapenemase profiles, and antimicrobial susceptibility patterns of CRKP isolates, as well as the clinical features and outcomes observed in infected or colonized patients. Materials and Methods: We conducted a retrospective analysis of clinical and microbiological data from patients with CRKP infections or colonization admitted between January 2023 and January 2024. Descriptive statistics were used to assess prevalence, resistance patterns, and patient outcomes. Two binary logistic regression models were applied to identify independent predictors of sepsis and in-hospital mortality. Results: Among 89 CRKP isolates, 45 underwent carbapenemase typing. More than half were metallo-β-lactamase (MBL) producers, with 44.4% co-harbouring NDM and OXA-48-like enzymes. Surgical intervention was associated with a significantly lower risk of sepsis (p < 0.01) and in-hospital mortality (p = 0.045), whereas intensive care unit (ICU) stay was a strong predictor of both outcomes. ICU admission conferred a 10-fold higher risk of sepsis (95%Cl 2.4–41.0) and a 40.8-fold higher risk of in-hospital death (95% Cl 3.5–473.3). Limitations: This single-center retrospective study included a limited number of isolates in certain groups. Additionally, cefiderocol (FDC) susceptibility was assessed by disk diffusion rather than by the broth microdilution method. Conclusions: Our study underscores the increasing prevalence of metallo-beta-lactamase-producing CRKP, particularly strains harbouring dual carbapenemases. Timely recognition of high-risk patients, combined with the implementation of targeted infection control measures and the integration of novel therapeutic options, is crucial to optimize clinical management and reduce mortality associated with CRKP. Full article

Wastewater is a hotspot for the spread of antimicrobial resistance (AR); therefore, bacteriophages offer a promising biocontrol alternative to overcome the limitations of conventional disinfection. This study evaluated the efficacy of bacteriophages and cocktails for the biocontrol of carbapenem-resistant Klebsiella pneumoniae (CR-Kp) (CG258 and ST307) and Escherichia coli producers of extended-spectrum β-lactamases (ESBL-Ec) (ST131) in simulated wastewater. A synthetic wastewater matrix was prepared in which bacterial viability and bacteriophage stability were assessed for 72 h. CR-Kp or ESBL-Ec strain were treated with individual bacteriophages or phage-cocktails (dosed in different ways) and bacterial loads were monitored for 54 h. The Klebsiella phages FKP3 and FKP14 eliminated 99% (−2.9 Log) of CR-Kp-CG258 at 54 h, and FKP10 reduced 99% (−2.15 Log) of the CR-Kp-ST307 strains. The Klebsiella phage-cocktail in a single dose reduced to 99.99% (−4.12 Log) of the CR-Kp-CG258 at 36 h. Coliphage FEC1 reduced to 2.12 Log (99%) of ESBL-Ec-bla_CTX-M-G9, and FEC2 and FEC4 reduced approximately 1 Log (90%) of ESBL-Ec-bla_CTX-M-G9 and bla_CTX-M-G1. The coliphage cocktail increased the reduction up to 2.2 Logarithms. This study provides evidence supporting the use of bacteriophage cocktails for the control of resistant bacteria in wastewater, a sustainable intervention to mitigate the spread of AR and support water reuse safety. Full article

Objectives: There is a scarcity of studies on multisite infections (MSIs) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). The primary objectives of this research were to determine the clinical characteristics of CRKP MSI, and the risk factors of infection and mortality. Methods: Patients with a CRKP bloodstream infection (BSI) were enrolled retrospectively between January 2017 and December 2021 in Xijing Hospital, China. The risk factors for CRKP MSI and mortality were evaluated. The demographic data, clinical and microbiological characteristics, therapy and outcomes were analyzed. Results: Among 101 patients, 74.3% (75/101) had a diagnosis of CRKP MSI, while 25.7% (26/101) of CRKP non-MSI. The overall case fatality rate was 42.6% (43/101). Multivariate analysis indicated that previous surgery (OR 3.971, 95% CI 1.504–10.480, p = 0.005) and ICU admission (OR 3.322, 95% CI 1.252–8.816, p = 0.016) were independent risk factors for CRKP MSI. ICU admission (OR 4.765, 95% CI 1.192–19.054, p = 0.027), a Pitt bacteremia score (PBS) > 4 (OR 3.820, 95% CI 1.218–11.983, p = 0.022) and thrombocytopenia (OR 8.650, 95% CI 2.573–29.007, p < 0.001) were independent risk factors for mortality due to CRKP MSI. Conclusions: Our findings confirmed that CRKP MSIs were associated with poorer outcomes. To improve prognosis, early screening of individuals at the highest risk is vital. Full article