Trends in hospital acquired NDM-producing Enterobacterales in Tuscany (Italy) from 2019 to 2021: impact of the COVID-19 pandemic

Epidemiology and outcomes associated with MBL-producing Enterobacterales: A systematic literature review

The increasing prevalence of infections due to metallo-β-lactamase (MBL)-producing Enterobacterales poses a serious concern given the limited treatment options available. This systematic literature review (SLR) describes the molecular epidemiology, geographical distribution, and clinical outcomes of such infections. Systematic searches of literature published between January 2013 and May 2023 were performed, and 39 studies with an MBL sample size of ≥25 isolates and ≥2 well-defined outcomes were eligible. Most of the studies were from Asia (21/39) followed by Europe (11/39) and evaluated more than two species (24/39). Overall, the percentage of MBL-producing isolates ranged from 6.8%-100.0%. Among 6620 MBL-producers, the majority were from Europe (3837/6620; 58.0%), followed by Asia (2079/6620; 31.4%). New Delhi MBL (NDM)-producers (5668/6620; 85.6%) were the most frequent across all regions, with NDM-1 as the common variant. The majority of IMP-producing isolates (586/592; 99.0%) came from Asia, while the majority of VIM-producing isolates were found in Europe (322/371; 86.8%). Studies focused on MBL-specific outcomes (n=28) reported reduced susceptibility (<80.0%) to most antimicrobials except for colistin and tigecycline. Six studies reported significantly longer hospital and/or ICU stay due to MBL-Enterobacterales compared to other infection groups. Common mortality measures reported were overall mortality (18.8%-57.0%; 9 studies), in-hospital mortality (11.1%-55.3%; 6 studies), and 30-day mortality (0%-36.4%; 7 studies). Previous antibiotic use (9 studies) and hospital and/or ICU stay (8 studies) were common risk factors for colonization/infection and mortality. Reporting of MBL prevalence across regions will provide a better understanding of the infection burden and prevent further spread. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023450571.

Candida albicans Horizontal Transmission in COVID-19 Patients Hospitalized in Intensive Care Unit

BACKGROUND

Invasive candidiasis is a predominant mycosis in hospitalized patients, and Candida albicans is the species most often responsible for this infection. Most candidiasis cases originate from endogenous mycobiota; therefore, Candida strains can easily be transferred among hospital patients and personnel. The aim of this study was to assess the possible horizontal transmission of C. albicans in patients with severe COVID-19 infection requiring hospitalization in the intensive care unit.

METHODS

In total, 59 C. albicans strains from 36 patients were collected from blood and lower-respiratory samples. The strains were genotyped using the RAPD method with the OPA-18 primer (5'-AGCTGACCGT-3'). Antifungal susceptibility testing was performed for amphotericin B (AMB), fluconazole (FCZ), voriconazole (VCZ), and anidulafungin (ANF) using the EUCAST method.

RESULTS

C. albicans strains were separated into 13 different groups according to their RAPD pattern. Two predominant clonal clusters of 17 strains isolated from 12 patients and 12 strains from 7 patients were identified, followed by clusters with 6, 4, and 8 strains isolated from 5, 4, and 3 patients, respectively. C. albicans strains were sensitive to AMB, FCZ, VCZ, and ANF, and antifungal susceptibility profiles were similar in all genetic clusters.

CONCLUSIONS

Our study indicates that C. albicans strains can spread horizontally. The routes of transmission for strains in the ward have not been explained due to there being insufficient data. The transmission could have been caused by the unintentional spread of pathogens by medical personnel.

Genomic surveillance of carbapenem-resistant Klebsiella pneumoniae reveals a prolonged outbreak of extensively drug-resistant ST147 NDM-1 during the COVID-19 pandemic in the Apulia region (Southern Italy)

OBJECTIVES

The recent worldwide spread of New Delhi metallo-beta-lactamase-producing Klebsiella pneumoniae (NDM-KP) in health-care settings remains a concern. The aim of the study was to describe an outbreak of extensively drug-resistant ST147 NDM-1-KP in the Apulia region of Southern Italy that occurred between 2020 and 2022 through genomic surveillance of carbapenem-resistant Enterobacterales.

METHODS

A total of 459 carbapenem-resistant KP isolates collected from patients hospitalised with bloodstream infections were tested using a commercial multiplex real-time polymerase chain reaction to identify carbapenemase genes. A subset of 27 isolates was subjected to whole-genome sequencing. Core-genome multilocus sequence typing was performed by analysing a panel of 4884 genes.

RESULTS

Molecular testing revealed that 104 (22.6%) isolates carried the carbapenemase NDM gene. Phylogenetic analysis of the 27 isolates subjected to whole-genome sequencing revealed high genetic relatedness among strains. All isolates were resistant to all first-line antibiotics. Virulome analysis identified the ybt locus, the two well-recognised virulence factors iucABCDiutA and rmpA, and the genes encoding the type 3 pilus virulence factor. Plasmids IncFIB(pkPHS1), IncFIB(pNDM-Mar), IncFIB(pQil), IncHI1B(pNDM-MAR), IncR, and Col(pHAD28) were identified in all isolates. Moreover, further analysis identified the IncFIB-type plasmid carrying the NDM-1 genes.

CONCLUSION

The increasing circulation of extensively drug-resistant NDM-1 ST147 KP strains in Southern Italy in recent years is worrisome, because these clones pose a real risk, particularly in hospital settings. Genomic surveillance is a crucial tool for early identification of emerging threats such as the spread of high-risk pathogens. Rapid infection control measures and antimicrobial stewardship are key to preventing further spread of hypervirulent KP strains.