Journal of global antimicrobial resistance最新文献

Objective: Infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) have a poor prognosis, particularly in immunocompromised patients. While carbapenemase production is the primary resistance mechanism in CRKP, other mechanisms may contribute synergistically to carbapenem resistance. Here, we describe a case in which extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae, initially susceptible to carbapenems, acquired carbapenem resistance without carbapenemase production following ceftolozane-tazobactam exposure.

Methods: Whole-genome sequencing was performed on ESBL-producing K. pneumoniae strains detected during the clinical course to investigate the relationship between the genetic characteristics and antimicrobial susceptibility, particularly to ceftolozane-tazobactam and carbapenems. Changes in the transcription levels of the beta-lactamase genes were also analyzed using reverse transcription quantitative PCR (RT-qPCR).

Results: Active surveillance stool culture before cord blood transplantation (CBT) identified colonization with an ESBL-producing K. pneumoniae strain. Febrile neutropenia occurred on day 7 after CBT and was treated empirically with ceftolozane-tazobactam. Fatal bacteremia developed on day 30 after CBT due to a carbapenemase-negative isolate resistant to both ceftolozane-tazobactam and carbapenems. Whole-genome sequencing analysis revealed that K. pneumoniae ST307 strains harboring bla_CTX-M-15, bla_SHV-28, and bla_TEM-1B acquired a nonsense mutation in ompK36 following ceftolozane-tazobactam exposure. RT-qPCR analysis documented a significant increase in bla_SHV-28 transcription after ceftolozane-tazobactam exposure.

Conclusions: This case demonstrates that K. pneumoniae without carbapenemase production can acquire carbapenem resistance through a combined resistance mechanisms following exposure to non-carbapenem antibiotics. Antimicrobial stewardship must be implemented comprehensively, not focused solely on specific antibiotics.

Objective: Hospital wastewater serves as a critical source of antimicrobial resistance genes (ARGs), particularly those associated with opportunistic pathogens like Raoultella ornithinolytica. This study aimed to characterize carbapenem-resistant R. ornithinolytica (CR-ROR) isolates carrying the tmexCD2-toprJ2 gene cluster from hospital sewage in Zhejiang province, China.

Methods: Wastewater samples collected from four hospitals in Zhejiang Province were screened for carbapenem-resistant isolates. Whole-genome sequencing using the Illumina platform, combined with bioinformatic analysis, was performed to investigate phylogenetic relationships, associated ARGs, and the structural features of plasmids in tmexCD2-toprJ2-positive CR-ROR isolates.

Results: Five genetically distantly related tmexCD2-toprJ2-positive CR-ROR isolates were identified. All exhibited multidrug-resistant (MDR) phenotypes and carried various ARGs, including carbapenemase genes such as bla_KPC-2, bla_NDM-1, and bla_IMP-4. Genomic analysis revealed that tmexCD2-toprJ2 was plasmid-borne and frequently flanked by mobile genetic elements (MGEs), suggesting a high risk of horizontal gene transfer.

Conclusions: The presence of tmexCD2-toprJ2-carrying CR-ROR in hospital sewage underscores the role of wastewater as a potential environmental reservoir for clinically resistant genes. Ongoing surveillance of hospital effluents is crucial for tracking the dissemination of high-risk antimicrobial resistance determinants and informing timely public health interventions.

Objectives: Epidemiological studies on Bacteroides fragilis group (BFG) species and their antimicrobial resistance (AMR) profiles remain scarce worldwide and are lacking in France. The aim of this study was to provide comprehensive national data on the distribution of BFG species, isolation sites, AMR and its potential regional disparity.

Methods: A retrospective multicenter study was conducted from January 2022 to December 2023 using routine data from 45 French hospitals. A total of 9,458 BFG isolates identified to the species level by MALDI-ToF were included. Antimicrobial susceptibility testing (AST) was performed according to French guidelines using either disc diffusion or gradient diffusion methods. AST results were collected for ten antibiotics: amoxicillin-clavulanate (AMC), piperacillin-tazobactam (PIT), imipenem (IMI), clindamycin (CLI), metronidazole (MET), moxifloxacin, tigecycline, linezolid, rifampicin, and chloramphenicol. A Bayesian statistical model was applied to estimate regional resistance frequencies with corresponding credible intervals.

Results: Bacteroides fragilis sensu stricto (B. fragilis) was the most prevalent species (62.4%), followed by Bacteroides thetaiotaomicron (14.2%). Resistance to IMI and MET remained low, while AMC, PIT, and CLI resistance varied markedly across species: 5.2%, 3.6%, and 34.4% for B. fragilis; 18.0%, 50.1%, and 72.9% for B. thetaiotaomicron; and 32.1%, 19.5%, and 75.2% for Parabacteroides distasonis, respectively. Bayesian modelling produced robust regional estimates for B. fragilis, revealing noticeable regional disparities, particularly for AMC, PIT, and MET.

Conclusion: Bayesian modeling revealed substantial interspecies and interregional differences in BFG resistance, highlighting the importance of species-level identification and localized surveillance to inform empirical antibiotic therapy.

Objective: Antimicrobial resistance (AMR) poses a significant and growing threat to public health globally, with Italy facing some of the highest resistance rates in Europe. This manuscript reviewed recent Italian intervention studies aimed at mitigating AMR across bacterial, fungal, and viral domains.

Methods: Strategies including antimicrobial stewardship (AMS), infection prevention and control (IPC), antifungal stewardship (AFS), and diagnostic advancements were evaluated. The evidence highlighted both the promise and limitations of Italy's current approach.

Results: While AMS and IPC programs have reduced antibiotic use, healthcare-associated infections, and costs, regional disparities, inconsistent implementation, and limited longitudinal surveillance remain critical challenges. The fungal resistance landscape is marked by rising threats like Candida auris, requiring urgent expansion of AFS programs. Italy's AMR strategy would benefit from improved IPC infrastructure, realtime data integration, and alignment with One Health principles.

Conclusions: Strengthening national coordination, supportinginnovation, and translating surveillance into action at the local level are crucial for turning policy into measurable progress. This review provides actionable insights to guide a more unified and responsive national AMR framework.

Introduction: Antimicrobial resistance (AMR) is a major global health threat addressed through National Action Plans (NAPs) aligned with the WHO Global Action Plan. Despite evidence that women are disproportionately affected - receiving 27% more antibiotic prescriptions than men - gender considerations remain largely absent from AMR policies.

Methods: We conducted a mixed-methods analysis of 132 NAPs published before December 2023. A two-stage approach was used: quantitative keyword frequency analysis of 10 gender-related terms (e.g., sex, gender, women), followed by a qualitative thematic analysis of top-tier NAPs, defined as those scoring ≥3 gender-related terms on a 10-point frequency scale derived from the former quantitative analysis. We also examined the gender composition of NAP curators and assessed correlations between gender representation and keyword inclusion.

Results: Only 14 NAPs (11%) mentioned the term 'gender'. The most frequent gender-related term was 'urinary tract infection' (UTI), appearing in 33% of NAPs. High-scoring NAPs were predominantly from low-income countries (mean score 2.4, SD = 2.2), especially in Africa (mean 2.5, SD = 2.3), compared to upper-middle-income countries (mean 1.1, SD = 1.07) and the Pan-American region (mean 1.0, SD = 0.9). Women were underrepresented among NAP curators: 47 NAPs were led entirely by men, while only 14 were led by women. No significant correlation was found between women's participation and gender keyword inclusion (β ≈ 0.11, P = 0.449).

Conclusion: Gender remains insufficiently integrated into AMR NAPs. The findings highlight the need for gender awareness policy development and the adoption of an intersectional framework to address overlapping social determinants that shape AMR vulnerability and response.

Backgroud: The spread of high-risk XDR Pseudomonas aeruginosa (Pa) clones is a global threat to public health. In Morocco, data on circulating clones, and genomic features of Pa isolates are lacking.

Objectives, materials and methods: Accordingly, this study performed whole-genome sequencing (WGS) (Illumina NextSeq500) of 18 Pa isolates from hospital (n=10) and the community (n=8) to identify their sequence type (ST) affiliation, antimicrobial resistance determinants, virulence factors, and phylogenetic relationships. Isolates were selected based on alarming resistance profiles from strains collected in Casablanca, Morocco between January and December 2021.

Results: These isolates were assigned as sequence type (ST) 773 (n=11), 308 (n=5) and 233 (n=1), in addition to a novel ST4902 for one hospital isolate. Carbapenem-resistance in hospital isolates was primarily attributed to acquired carbapenemases (NDM-1 in ST773 and ST308 clones). In contrast, resistance in one hospital (CSPa93) and one community isolate (cSPa43) was associated with mutations in outer membrane protein. Fluoroquinolone resistance correlated with the carriage of qnrVC1 and crpP genes, along with mutations in the quinolone resistance-determining regions (QRDR). The isolates also carried diverse aminoglycoside modifying enzymes and 16S rRNAmethyltransferase genes. Genomic analysis also identified multiple virulence genes in these isolates, notably exoU in ST308 and ST773 isolates. Phylogenetic analysis further revealed hospital-adapted strains being genetically related to each other and to community strains.

Conclusion: This first genomic investigation of circulating XDR Pa clones in both hospital and community settings in Morocco using WGS highlights the urgent need for enhanced surveillance and targeted strategies to contain the spread of XDR high-risk clones.