Emerging Antimicrobial-Resistant High-Risk Klebsiella pneumoniae Clones ST307 and ST147.

There is an enormous global public health burden due to antimicrobial-resistant (AMR) Klebsiella pneumoniae high-risk clones. K. pneumoniae ST307 and ST147 are recent additions to the family of successful clones in the species. Both clones likely emerged in Europe during the early to mid-1990s and, in a relatively short time, became prominent global pathogens, spreading to all continents (with the exception of Antarctica). ST307 and ST147 consist of multiple clades/clusters and are associated with various carbapenemases (i.e., KPCs, NDMs, OXA-48-like, and VIMs). ST307 is endemic in Italy, Colombia, the United States (Texas), and South Africa, while ST147 is endemic in India, Italy, Greece, and certain North African countries. Both clones have been introduced into regions of nonendemicity, leading to worldwide nosocomial outbreaks. Genomic studies showed ST307 and ST147 contain identical gyrA and parC mutations and likely obtained plasmids with blaCTX-M-15 during the early to mid-2000s, which aided in their global distribution. ST307 and ST147 then acquired plasmids with various carbapenemases during the late 2000s, establishing themselves as important AMR pathogens in certain regions. Both clones are likely underreported due to restricted detection methodologies. ST307 and ST147 have the ability to become major threats to public health due to their worldwide distribution, ability to cause serious infections, and association with AMR, including panresistance. The medical community at large, especially those concerned with antimicrobial resistance, should be aware of the looming threat posed by emerging AMR high-risk clones such as K. pneumoniae ST307 and ST147.

A Fatal Bacteremia Caused by Hypermucousviscous KPC-2 Producing Extensively Drug-Resistant K64-ST11 Klebsiella pneumoniae in Brazil.

We report a fatal bacteremia caused by Klebsiella pneumoniae in a 60-70-year-old patient from Brazil. The genomic analysis of three isolates (from blood culture, nasal and anal swabs) showed that the bacteremia was caused by a KPC-2 producing extensively drug-resistant K64-ST11 hypermucousviscous K. pneumoniae (hmKP) harboring several virulence and antimicrobial resistance genes. Although the isolates did not present virulence markers associated with hypervirulent K. pneumoniae (hvKP), they showed invasion and toxicity to epithelial Hep-2 cells; resistance to cell microbicidal mechanisms; and blood and human serum survival, evidencing their pathogenic potential. This study highlights the risk of infection caused by hmKp strains not characterized as hvKP as well as the clinical implications and difficulty of treatment, especially in elderly or immunocompromised patients.

Global Molecular Epidemiology of IMP-Producing Enterobacteriaceae.

International data on the molecular epidemiology of Enterobacteriaceae with IMP carbapenemases are lacking. We performed short-read (Illumina) whole-genome sequencing on a global collection of 38 IMP-producing clinical Enterobacteriaceae (2008 to 2014). IMP-producing Enterobacteriaceae (7 varieties within 11 class 1 integrons) were mainly present in the South Pacific and Asia. Specific blaIMP-containing integrons (In809 with blaIMP-4, In722 with blaIMP-6, and In687 with blaIMP-14) were circulating among different bacteria in countries such as Australia, Japan, and Thailand. In1312 with blaIMP-1 was present in Klebsiella pneumoniae from Japan and Citrobacter freundii from Brazil. Klebsiella pneumoniae (n = 22) was the most common species; clonal complex 14 (CC14) from Philippines and Japan was the most common clone and contained In1310 with blaIMP-26 and In1321 with blaIMP-6 The Enterobacter cloacae complex (n = 9) consisted of Enterobacter hormaechei and E. cloacae cluster III. CC78 (from Taiwan) containing In73 with blaIMP-8 was the most common clone among the E. cloacae complex. This study highlights the importance of surveillance programs using the latest molecular techniques for providing insight into the characteristics and global distribution of Enterobacteriaceae with blaIMP genes.