Can you GES which carbapenemase caused this CPE outbreak?

An unusual and interesting outbreak of CPE was published recently in Clinical Infectious Diseases. Several key points: don’t rely solely on a PCR detecting the “Big 5” carbapenemases (NDM, KPC, OXA-48, IMP, VIM) – at some point you need to test for phenotypic carbapenemase activity; WGS can really help us in unravelling complex transmission routes; and covert plasmid propagation within and between species is a reality.

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CPE contamination of hospital wastewater: smoking gun or innocent bystander?

A recent US study has investigated CPE contamination of sinks, drains, and wastewater. Carbapenemase-producing bacteria were identified throughout the drainage and water system, from drains in patient rooms, right through to wastewater sampled through manholes adjacent to the hospital. My main question in all of this is whether this huge reservoir of carbapenemases in hospital wastewater is a risk for patients. The lack of genetic similarity between isolates in hospital wastewater and isolates from patients suggest not, but I suspect there’s an indirect link and these carbapenemases find their way into isolates affecting humans, which is supported by genetic links between the plasmids carrying the carbapenemases.

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Looking back on a CPE plasmid attack in the Northwest of England

A genomic study of 44 isolates of CPE from various species identified between 2008 and 2010, mainly from the Northwest of England, has concluded that plasmids played a key role in the early dissemination of CPE.

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Promiscuous plasmids: a rapid reflection from ECCMID 2017

I came to ECCMID 2017 with a very specific question: do we need to think beyond ‘same-bug-same-gene’ horizontal transmission from a practical IPC view point in order to address the threat of IPC? The answer, unfortuantely, is yes!

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Acronyms for carbapenem-resistant bacteria (again)

I am currently involved in some research that requires a clear distinction between CPE (i.e. Enterobacteriaceae that produce a carbapenemase) and non-carbapenemase-producing CRE. Since ‘non-carbapenemease-producing carbapenem-resistant Enterobacteriaceae’ is a bit of a mouthful, I need to come up with some sort of acronym. I would appreciate your thoughts on the scheme set out below:

You can read more thoughts on acronyms for carbapenem-resistant bacteria in a previous post here.

The carbapenemase is out there

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A PNAS paper on the genomic diversity of carbapenemase producing bacteria in the US reports strong evidence of carbapenamase (an enzyme produced by bacteria that breaks down carabapenem antibiotics) activity but no sign of a carbapenemase gene. This provides a timely reminder that we are only really scratching the surface in our understanding of carbapenemases and how they work.

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KPC Casanova carbapenemase

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The risk of interspecies transmission of carbapenemase genes is a real concern. We can barely get our heads around many different types of carbapenemase in a whole host of Gram-negative bacteria (compare the relative simplicity of methicillin resistance in S. aureus: a single gene, in a single species). Throw in interspecies horizontal transmission of carbapenemases and things get really tricky! Do we implement different control strategies to try to interrupt the transmission of carbapenemases (in contrast to the organisms themselves)? Could you have a multispecies outbreak of a carbapenemase on your hands and not even realise it?

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