On the origin of multidrug-resistant Gram-negative bacteria (MDR-GNB)

The colour of the global crisis of antibiotic resistance is red (if te Gram stain is your reference). In rich countries we have ESBL-producing Enterobacterales (mainly E. coli), but the real problem are carbapenemase-producing strains (Klebsiella, Pseudomonas and Acinetobacter) that are already endemic in lower and middle-income countries. The unanswered question is “where did these resistant bacteria come from”? Animals or bathrooms? Continue reading

What about E. coli ST131 (part 2); is it foodborne?

Last November I blogged on E. coli ST131, frequently portrayed as a pandemic clone, combining hypervirulence, ciprofloxacin resistance and ESBL production. The question is whether the undeniable high prevalence of this bug among clinical isolates results from its virulence and antibiotic resistance or whether it is just a reflection of carriage prevalence in the general population, without any relationship to virulence or resistance. Two recently published studies try to shed new light on the debate; one bringing in chicken retail meat as the source…… Continue reading

What about E. coli ST131?

One of the faces of the global antibiotic resistance crisis is Escherichia coli ST131, frequently portrayed as a pandemic clone, combining hypervirulence, ciprofloxacin resistance and ESBL production. A recent study in Genome Research, a journal you may not read every month, though, sheds a whole new light on this “superbug”. Continue reading

Real-time whole genome sequencing (RT-WGS) & spread of resistant bacteria

At last weeks’ ICPIC I crossed arguments with John Rossen on the question whether RT-WGS helps us to control the spread of resistant bacteria. The setting is the hospital and the definition of RT is “in time to guide essential decision making”. Is RT-WGS a “need-to-have” or a “nice-to-have” thing? Continue reading

It’s transmission doc, but not as we know it

A groundbreaking study just published in PLOS Genetics provides new insight into the transmission dynamics of bacteria in the ICU setting using WGS. The ambitious authors performed WGS on virtually all bacterial isolates from ICUs in a US hospital for a year. The first surprise was that 12% of the bacteria considered clinically relevant were previously undescribed.

The next – and perhaps biggest – surprise was that whilst transmission of the usual suspect pathogens (MRSA, VRE etc) was rare, 9% of the other bacteria were shared by multiple patients, often with overlapping admissions (see the figure below). This suggests that there is a fair bit of transmission going on under the radar in the ICU setting.

Figure: Clonal lineages extending across multiple patients.

WGS ICU timeline

This study reminds me of one published in CID a few years ago showing that outbreaks of resistance probably occur regularly and usually undetected across multiple species.

So, is it time to start using WGS for all bacteria identified in the clinical laboratory? Not quite yet I don’t think: the analytical methods have not yet caught up with the sequencing technology. But this study is a glimpse of the future, no doubt about it.