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Klebsiella pneumoniae is consistently ranked among the most problematic multidrug-resistant bacterial pathogens in healthcare systems. Developing novel treatments requires a better understanding of its interaction with the host environment. Although bacteria can synthesize fatty acids, emerging findings suggest a potential preference for their acquisition from the host. Fatty acid profiling of mice revealed a dramatic increase in the level of hepatic lipids during K . pneumoniae infection. The K . pneumoniae fatty acid composition and uptake capabilities were found to be largely clonally conserved. Correlations between fatty acid uptake, outer membrane vesicle production, and cell permeability were observed, but this did not translate to alterations in cell morphology, capsule production, or antimicrobial susceptibility. Importantly, hyper-capsulation did not prevent the uptake of hydrophobic fatty acids. The uptake of a saturated fatty acid by hypervirulent K . pneumoniae isolate may provide insights into the clinical association of K . pneumoniae infections with hyperlipidemic and/or obese individuals.

Salmonella Paratyphi A, one of the major etiologic agents of enteric fever, has increased in prevalence in recent decades in certain endemic regions in comparison to S. Typhi, the most prevalent cause of enteric fever. Despite this increase, data on the prevalence and molecular epidemiology of S. Paratyphi A remain generally scarce. Here, we analysed the whole genome sequences of 216 S. Paratyphi A isolates originating from Kathmandu, Nepal between 2005 and 2014, of which 200 were from patients with acute enteric fever and 16 from the gallbladder of people with suspected chronic carriage. By exploiting the recently developed genotyping framework for S. Paratyphi A (Paratype), we identified several genotypes circulating in Kathmandu. Notably, we observed an unusual clonal expansion of genotype 2.4.3 over a four-year period that spread geographically and systematically replaced other genotypes. This rapid genotype replacement is hypothesised to have been driven by both reduced susceptibility to fluoroquinolones and genetic changes to virulence factors, such as functional and structural genes encoding the type 3 secretion systems. Finally, we show that person-to-person is likely the most common mode of transmission and chronic carriers seem to play a limited role in maintaining disease circulation., Competing Interests: ‘The authors have declared that no competing interests exist.’, (Copyright: © 2024 Mylona et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objectives: Community-onset bloodstream infections (BSIs) caused by carbapenemase-producing Enterobacter cloacae complex (ECC) species are increasing internationally. This observation suggests that ECC are emerging pathogens, requiring for detailed understanding on their genomic epidemiology including transmission dynamics and antimicrobial resistance profiles., Patients and Methods: We performed WGS on 79 Enterobacter spp. isolated from the patients with clinically significant BSIs and admitted to emergency department of a major tertiary hospital in Nepal between April 2016 and October 2017., Results: We identified 5 species and 13 STs of ECC. Enterobacter xiangfangensis ST171, one of the globally emerging carbapenem resistant ECC clones with epidemic potential, was the most prevalent (42%). Phylogenetic analysis showed a large (>19 400 SNPs) core genome SNP distance across major STs, which was minimal (<30 SNPs) among the isolates of each prevalent ST, suggesting the relatively recent importation of major STs followed by local clonal expansions. Genomic evidence for resistance to all major antimicrobial classes except for colistin and macrolides was detected. A limited number of isolates also carried bla NDM-1 ( n  = 2) and bla OXA-48 ( n  = 1) carbapenemase genes. Virulence factors encoding siderophores (24%), T6SSD (25%) and fimbriae (54%) were detected., Conclusions: Our study highlighted that MDR ECC clones are important pathogens of BSIs in community. Though of low prevalence, carbapenem resistance observed in our ECC isolates raised concern about further community dissemination, underscoring the need for community surveillance to identify MDR ECC clones with epidemic potential., (© The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)