First Report of Whole-Genome Sequence of Colistin-Resistant Klebsiella quasipneumoniae subsp. similipneumoniae Producing KPC-9 in India.

AIM: Klebsiella pneumoniae carbapenemase (KPC) is a class A carbapenemase endemic in the United States, China, South America, and Europe but is rarely reported from India. A single report of KPC-9 from K. pneumoniae in Israel has been published. K. pneumoniae has been classified into three phylogenetic groups: group 1 consists of K. pneumoniae and its subspecies, group 2 consists of Klebsiella quasipneumoniae and its subspecies, and group 3 consists of Klebsiella variicola. This is the first report of whole-genome sequencing of colistin-resistant K. quasipneumoniae subsp. similipneumoniae harboring blaKPC-9 gene.

RESULTS: The isolate was obtained from the culture of a respiratory catheter tip from a 41-year-old woman with traumatic brain injury. Whole-genome sequencing showed the presence of blaOKP-B-3 gene and hence it was identified as K. quasipneumoniae subsp. similipneumoniae. The isolate was resistant to all antimicrobials except tigecycline. Colistin resistance was chromosomally mediated; mcr-1 to mcr-5 genes and their variants were not identified. The isolate belonged to the novel clonal type ST2957.

CONCLUSION: The isolation of KPC-9 from India, a nonendemic region, and in an isolate of K. quasipneumoniae highlights the importance of accurate identification of Klebsiella species and determination of mechanism of resistance. The novel sequence type obtained indicates evolution of the organism and acquisition of plasmid-mediated resistance. The occurrence of KPC in India is a potential public health threat.