Colonization with Staphylococcus aureus and Klebsiella pneumoniae causes infections in a Vietnamese intensive care unit

• Published in: Microbial genomics Vol. 7; no. 2
• Main Authors: Thuy, Duong Bich, Campbell, James, Thuy, Cao Thu, Hoang, Nguyen Van Minh, Voong Vinh, Phat, Nguyen, To Nguyen Thi, Nguyen Ngoc Minh, Chau, Pham, Duy Thanh, Rabaa, Maia A, Lan, Nguyen Phu Huong, Hao, Nguyen Van, Thwaites, Guy E, Thwaites, C Louise, Baker, Stephen, Chau, Nguyen Van Vinh, Chung The, Hao
• Format: Journal Article
• Language: English
• Published: England Microbiology Society 01-02-2021
• Subjects: Adult; Aged; Drug Resistance, Multiple, Bacterial; Female; High-Throughput Nucleotide Sequencing; Humans; Intensive Care Units; Klebsiella Infections - microbiology; Klebsiella pneumoniae - classification; Klebsiella pneumoniae - genetics; Klebsiella pneumoniae - isolation & purification; Male; Microbial Sensitivity Tests; Middle Aged; Phylogeny; Prospective Studies; Staphylococcal Infections - microbiology; Staphylococcus aureus - classification; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Vietnam; Whole Genome Sequencing; Vietnam; intra-patient diversity; hospital-acquired infections; colonization; Staphylococcus aureus; hypervirulent Klebsiella pneumoniae
• ISSN: 2057-5858; 2057-5858
• DOI: 10.1099/mgen.0.000514

Pre-existing colonization with
or
has been found to increase the risk of infection in intensive care patients. We previously conducted a longitudinal study to characterize colonization of these two organisms in patients admitted to intensive care in a hospital in southern Vietnam. Here, using genomic and phylogenetic analyses, we aimed to assess the contribution these colonizing organisms made to infections. We found that in the majority of patients infected with
or
, the sequence type of the disease-causing (infecting) isolate was identical to that of corresponding colonizing organisms in the respective patient. Further in-depth analysis revealed that in patients infected by
ST188 and by
ST17, ST23, ST25 and ST86, the infecting isolate was closely related to and exhibited limited genetic variation relative to pre-infection colonizing isolates. Multidrug-resistant
ST188 was identified as the predominant agent of colonization and infection. Colonization and infection by
were characterized by organisms with limited antimicrobial resistance profiles but extensive repertoires of virulence genes. Our findings augment the understanding of the link between bacterial colonization and infection in a low-resource setting, and could facilitate the development of novel evidence-based approaches to prevent and treat infections in high-risk patients in intensive care.