NGS Journal Club
Mette Voldby Larsen PhD, associate professor
DTU-SystemsBiology
Paper
A possible MRSA outbreak on a Special Care Baby Unit (SCBU) was analyzed using conventional methods.
Colonized patients from SCBU and MRSA isolates with the same antibiotic resistance profile from patients in other wards or from society were whole-genome sequenced.
What was done:
Antibiogram profiles
Red: ResistantWhite: Susceptible
Epidemiological map of 14 infants from SCBU
Possible outbreak?
Not the same antibiotics resistance profile – not the same outbreak
New case after cleaning?
Then they start sequencing…
A
Phylogenetic tree based on core snps
All ST2371
Antibiogram profiles
Red: Resistant
Green: Initially tested as susceptible, but re-testing shows it is resistant
White: Susceptible
Extended search
• MRSA isolates with similar antibiotic resistance profiles from other wards are sequenced (retro- and prospectively) = 19 isolates• Ten of these are also ST2371
Epidemiological map, incl. 10 cases outside the SCBU
154 employees are screened for MRSA – ONE is found positive for ST2371
Antibiogram profiles for the later cases
Epidemiological map, incl. 11 cases outside the SCBU and one employee.
Conclusion
• WGS performed better for identifying patients and citizens part of the outbreak
• Identification of the outbreak led to the investigation and the identification of a hospital employed carrier