JAC-Antimicrobial Resistance最新文献

Objectives: This study aimed to investigate the prevalence and characteristics of Aspergillus lentulus clinical and environmental isolates in Taiwan.

Methods: Aspergillus isolates obtained from patients at three hospitals and from 530 soil samples across Taiwan were screened. A. lentulus, confirmed by calmodulin sequencing, was subjected to antifungal susceptibility testing and cyp51A analyses. Soil samples yielding A. lentulus were analysed for residues of 25 azole fungicides.

Results: Nine A. lentulus isolates were identified, which included seven (1.2%, 7/601) isolates from three antifungal-naïve patients out of 601 Aspergillus section Fumigati clinical isolates and two (0.3%, 2/659) isolates out of 659 Aspergillus soil isolates. All isolates developed white colonies and failed to grow at 48°C. They were susceptible to anidulafungin but showed reduced susceptibility to amphotericin B (AmB), voriconazole and azole fungicides. One heart transplant recipient with proven invasive pulmonary aspergillosis (IPA) initially showed suboptimal response to voriconazole monotherapy but was cured with a combination of voriconazole-caspofungin, liposomal AmB (LAmB)-caspofungin, along with surgery, followed by voriconazole maintenance therapy. Among two critically ill patients with probable IPA, one survived with micafungin, while the other died of aspergillosis despite sequential isavuconazole and LAmB monotherapy. Clinical and environmental isolates sharing identical Cyp51A sequence are identified, matching the Cyp51A sequence of A. lentulus NIID0096. Flusilazole (0.0009 mg/kg) was detected in one soil sample.

Conclusions: This study raises concerns about health threat posed by human pathogenic A. lentulus originating from natural environments and underscores the need for increased clinical and laboratory vigilance regarding A. lentulus infections.

Background: Antibiograms provide effective support for empirical prescribing and antimicrobial stewardship programmes (ASPs). In low-resource settings, microbiology systems to develop antibiograms may be rudimentary or entirely lacking, which may place such facilities at a disadvantage. Notwithstanding this, facilities should use what they have to support ASPs to inform evidence-based antibiotic use. We report how an antibiogram was developed at a district hospital in Ghana to support its ASP.

Methods: This was a retrospective analysis of antibiotic susceptibility testing (AST) results from the University Hospital, KNUST from January to December 2021. Data were exported from the hospital's laboratory information system to Microsoft Excel (Version 2013). IBM SPSS Statistics (Version 25) and Epi Info™ Version 7 were used for statistical analyses.

Results: Overall, 1949 cultures were performed, 392 (20.1%) growing bacterial pathogens. Per the CLSI M39-A4 standard guidelines for antibiograms, only 360 of the bacterial isolates were used for the analyses. The majority of isolates were from urine (187; 51.9%). Among the Gram-negative bacteria, there was low susceptibility to amoxicillin/clavulanic acid (28%), cephalosporins (11%-35%) and meropenem (21%), but high susceptibility to amikacin (96%) and levofloxacin (81%). Low susceptibility of Gram-positive isolates to amoxicillin/clavulanic acid (34%), meropenem (34%) and penicillins (27%-35%) was also recorded, but high susceptibility to ciprofloxacin (80%), gentamicin (79%) and vancomycin (76%).

Conclusion: High levels of bacterial resistance to cephalosporins and meropenem in the antibiogram were reported. This antibiogram highlighted the urgent need for pragmatic steps to curb antibiotic resistance through ASPs using strategies that positively improve clinicians' knowledge and prescribing practices.

Background: Stenotrophomonas sepilia, identified in 2021, is part of the Stenotrophomonas maltophilia complex (Smc) and shares high genomic identity with S. maltophilia. Resistance to levofloxacin, the recommended fluoroquinolone for S. maltophilia, is being increasingly reported. Recent studies indicate that levonadifloxacin, a novel benzoquinolizine, may be more effective. This study evaluates the antimicrobial efficacy of levofloxacin and levonadifloxacin against clinical isolates of S. sepilia.

Objectives: To assess the antibacterial effectiveness of levofloxacin and levonadifloxacin against novel pathogen S. sepilia.

Methods: A total of 116 S. maltophilia isolates, identified by MALDI-TOF MS, were collected from five centres across India. S. sepilia was confirmed by PCR using primers targeting a unique genomic sequence (NCBI accession number LXXZ00000000.1). Minimum inhibitory concentrations (MICs) of levonadifloxacin and levofloxacin were determined by using the microbroth-dilution method and Etest as per CLSI guidelines. The levofloxacin breakpoint was used to interpret MICs of levonadifloxacin.

Results: Among a total of 116 circulating S. maltophilia isolates collected, 46 were identified as S. sepilia, representing a prevalence rate of (∼40%), thus highlighting its significance as an important pathogen within the Smc. Both levofloxacin and levonadifloxacin demonstrated a 98% inhibition rate against the 46 S. sepilia tested. Only one S. sepilia isolate resistant to levofloxacin showed intermediate susceptibility to levonadifloxacin, which consistently had lower MICs.

Conclusions: Levofloxacin and levonadifloxacin show similar susceptibility rates against S. sepilia, with levonadifloxacin exhibiting lower MICs. Further studies are required to establish clinical utility of levonadifloxacin in managing these infections.

Objectives: Despite the global health risk of carbapenem-resistant Enterobacterales (CRE), especially carbapenemase-producing Enterobacterales (CPE), Japan reports a significantly low frequency of CRE with a predominance of IMP-type carbapenemases. This study aimed to investigate the prevalence and characteristics of CRE isolated from hospitals in the city of Nara, Japan.

Methods: We obtained 171 CRE isolates from 16 791 Enterobacterales isolated at 23 hospitals in Nara between January 2018 and December 2021. Isolates of CPE were characterized through antimicrobial susceptibility testing, the carbapenem inactivation method, PCR and DNA sequencing. Genotypic diversity of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae was determined via MLST and PFGE.

Results: The prevalence of CRE between 2018 and 2021 was 1.02%, gradually decreasing from 1.13% to 0.74%. Ninety-nine isolates were identified as CPE, representing six species. Ninety-seven CPE isolates harboured bla _IMP-6, while the remaining two carried either bla _IMP-1 or bla _IMP-19. Genotype analysis identified ST131 as the dominant genotype for E. coli, but none for K. pneumoniae. PFGE results suggested clonal spread of CPE in Hospital A, where CRE was isolated in high numbers (n = 44).

Conclusions: In this study, CRE prevalence was marginally higher than previously reported in Japan, but still low in frequency. A predominance of Enterobacterales harbouring bla _IMP-6 was confirmed in Nara. The spread of CPE at Hospital A suggested the possibility of a nosocomial outbreak due to bla _IMP-6 transmission via plasmids or clonal spread. Continued monitoring is crucial for effective management of CRE prevalence in the region.

Since the introduction of quinolone and fluoroquinolone antibiotics to treat bacterial infections in the 1960s, there has been a pronounced increase in the number of bacterial species that have developed resistance to fluoroquinolone treatment. In 2017, the World Health Organization established a priority list of the most critical Gram-negative resistant pathogens. These included Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli. In the last three decades, investigations into the mechanisms of fluoroquinolone resistance have revealed that mutations in the target enzymes of fluoroquinolones, DNA gyrase or topoisomerase IV, are the most prevalent mechanism conferring high levels of resistance. Alterations to porins and efflux pumps that facilitate fluoroquinolone permeation and extrusion across the bacterial cell membrane also contribute to the development of resistance. However, there is a growing observation of novel mutants with newer generations of fluoroquinolones, highlighting the need for novel treatments. Currently, steady progress has been made in the development of novel antimicrobial agents that target DNA gyrase or topoisomerase IV through different avenues than current fluoroquinolones to prevent target-mediated resistance. Therefore, an updated review of the current understanding of fluoroquinolone resistance within the literature is imperative to aid in future investigations.

Antimicrobial resistance (AMR) is a critical health challenge in Nigeria as in many other countries in the sub-Saharan region of Africa. Our article describes how the challenges in the regulation and operations of Patent and Proprietary Medicine Vendors (PPMVs) in Nigeria provide a blind spot for the underuse of antimicrobials. This article also sheds light on how patients' antibiotic use and seeking behaviour facilitate this unwholesome practice. In addition, our article looks at the social determinants of this practice, such as poverty and poor education, and proffers solutions towards solving it. While previous research has investigated the knowledge, perceptions and attitudes of PPMVs towards antimicrobial use and AMR, our article is the first to critically raise concerns about the common practice of antimicrobial underdosing in Nigeria.

Background: The transmission of carbapenemase-producing Enterobacterales (CPE) in the external environment, especially through food, presents a significant public health risk.

Objectives: To investigate the prevalence and genetic characteristics of CPE in food markets of Dhaka, Bangladesh, using WGS.

Methods: CPE isolates were obtained from different food and water samples collected from food markets in the southern part of Dhaka, Bangladesh. The isolates subsequently underwent molecular typing, WGS employing both short- and long-read sequencers, and plasmid analysis.

Results: This study unveiled an extensive spread of CPE, with no significant difference in contamination rates observed in samples (N = 136), including meat (n = 8), fish (n = 5), vegetables (n = 36) or various food-washed water (n = 65) from markets near hospitals or residential areas. Thirty-eight Enterobacterales from 33 samples carried carbapenemase genes (bla _{NDM-1, -4, -7}, bla _KPC-2, bla _OXA-181 or bla _IMI-1). Among these, the high-risk Escherichia coli ST410 clone was the most prevalent and distributed across various locations. Furthermore, the identification of IncHI2 plasmids co-harbouring resistance genes like bla _NDM-5 and mcr-1.1, without discernible epidemiological connections, is a unique finding, suggesting their widespread dissemination.

Conclusions: The analysis unveils a dynamic landscape of CPE dissemination in food markets, underscored by the proliferation of novel IncHI2 hybrid plasmids carrying both colistin- and carbapenem-resistance genes. This illuminates the ever-evolving landscape of antimicrobial resistance in Dhaka, urging us to confront its emergent challenges.

Background: Antibiotic resistance is rising globally and is a major One Health problem. How much person-to-person transmission or 'contagion' contributes to the spread of resistant strains compared with antibiotic usage remains unclear. As part of its COVID-19 response, Australia introduced strict people movement restrictions in early 2020. Along with internal lockdown measures, movement of people into Australia from overseas was severely restricted. These circumstances provided a unique opportunity to examine the association of people movements with changes in resistance rates.

Methods: Monthly resistance data on over 646 000 Escherichia coli urine isolates from 2016 till 2023 were modelled for statistical changes in resistance trends during pre-lockdown, lockdown and post-lockdown periods. Data were available for three clinical contexts (community, hospital and aged-care facilities). Data were also available for antibiotic usage volumes and movements of people into Australia.

Results: In 2020, arrivals into Australia decreased by >95%. Antibiotic community use fell by >20%. There were sharp falls in trend rates of resistance for all antibiotics examined after restrictions were instituted. This fall in trend rates of resistance persisted during restrictions. Notably, trend rates of resistance fell in all three clinical contexts. After removal of restrictions, an upsurge in trend rates of resistance was seen for nearly all antibiotics but with no matching upsurge in antibiotic use.

Conclusions: Restricting the movement of people appeared to have a dramatic effect on resistance rates in E. coli. The resulting reduced person-to-person interactions seems more closely associated with changes in antibiotic resistance than antibiotic usage patterns.