I’ve written this post in preparation for Wednesday’s Journal Club (register here) in collaboration with IPC Partners

Burkholderia are fascinating genus of bacteria which I had the pleasure of doing some post doctoral work on. The ability of the species to innately resist antibiotics and preservatives, as well as prolonged persistence in the environment means the organisms can cause challenges for healthcare organisations and infection prevention and control. I have seen an increasing number of publications in recent years linking outbreaks to contaminated medical devices and even disinfectants (good systematic review here). Therefore this paper published in The Journal of Hospital Infection investigating a Burkholderia cenocepacia outbreak using whole genome sequencing (WGS) grabbed my interest. I have also been interested in the role of WGS in detection and prevention of outbreaks (see a previous IPC Partners by Dr Alex Sundermann) and the potential benefits.  

Design and methods 

• The outbreak took place in an intensive care unit in Vietnam between May and August 2023 affecting 19 patients 
• Environmental sampling of high touch surfaces, fluid samples and medical devices was performed 
• WGS was performed on all available B. cenocepacia complex (Bcc) isolates using Illumina Hiseq platform. In total WGS was performed on 20 clinical isolates and 3 environmental isolates (from used syringes)
• Prior to investigating with WGS it had been suspected that positive clinical Bcc samples were the result of blood culture contaminants

Key findings

• Environmental sampling identified 3 B. cenocepacia isolates from separate syringes using to deliver IV fluids 
• No growth of microorganisms was detected in samples of skin antiseptics, hand sanitizers and ultrasound gel (surprising to me!)
• WGS confirmed that all B. cenocepacia isolates from clinical and environmental samples belonged to the same sequence type 
• The isolates carried an array of acquired antimicrobial resistance genes predicted to confer resistance to carbapenems, sulfonamide, and tetracycline
• The source of the outbreak was not identified but limitations in the preparation and administration of IV fluids were identified 

What this means for IPC

• WGS can successfully be used to aid hospital outbreak investigation which is particularly relevant for complex bacteria such as Burkholderia, in which traditional detection and typing methods often have low sensitivity
• WGS can be implemented successfully in low and medium income countries such as Vietnam but requires strong collaboration between IPC, clinical microbiologists and molecular biologists 
• WGS allowed species identification which is important in this context, as the Bcc complex comprises of more than 22 different species, exhibiting differing epidemiological and pathologic features, and varying susceptibility to antibiotics both in vitro and in vivo. Misidentification may lead to inappropriate antimicrobial therapy. 
• The study highlights the importance of following aseptic practices and procedures in handling and administration of intravenous medications to avoid bacterial contamination and prevent infection