Andrew Henderson

Great team effort to get this done! @evanbursle @padstamundo @jesusrbano @davidantibiotic @adm_stewart

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial Yep

@Hendonet @padstamundo @draghafur @davidantibiotic @MerinoTrial So these are the vitek sensitives (limited to <=8) stratified by zone (x axis) and bmd mic (colors)?

Out in CID - Association between minimum inhibitory concentration, beta-lactamase genes and mortality for patients treated with piperacillin/tazobactam or meropenem from the MERINO study @merinotrial @padstamundo academic.oup.com/cid/advance-ar…

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial Interesting thought! Here is the PTZ zone diameter distribution stratified by MIC for isolates with VITEK MIC <16mg/L. I can do the same plot stratified by BL gene present, but almost all the 16mg/L and 32mg/L have OXA1 present.

@Hendonet @padstamundo @draghafur @davidantibiotic @MerinoTrial Eagerly waiting -- I'm very much into the idea of using one test to set the pretest probability for the second these days. For instance using fecal carriage of ARO to predict susceptibility in subsequent same organism BSI.

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial Haha yes it is! I’ll see if I can get round to that tonight/tomorrow morning.

@Hendonet @padstamundo @draghafur @davidantibiotic @MerinoTrial It is akin to your work on PSSA -- enrich PSSA using vitek and then confirm with disc diffusion. It is also what we did for a while when some of the vitek cards were considered unreliable for PTZ (? 2009)

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial pip/taz disk alone is probably enough and ignore the vitek, though the new Etest is probably better. Alternative: If susc by PTZ disk, CDDST confirms ESBL and amox/clav disk is susc, then sens and spec of 91.6% and 64.5% to exclude oxa strains

@Hendonet @padstamundo @draghafur @davidantibiotic @MerinoTrial Thanks for this! Do you think combining the results for both Vitek MIC and Disk zone together would add any further accuracy?

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial The main issue relates to the co-presence of OXA1 genes with ESBLs and the inability to differentiate the two using any phenotypic test. Reducing the susceptible breakpoint to <= 8mg/L as proposed by EUCAST does solve some issues, but still splits the OXA1/ESBL population.

@DrToddLee @padstamundo @draghafur @davidantibiotic @MerinoTrial

Association between minimum inhibitory concentration, beta-lactamase genes and mortality for patients treated with piperacillin/tazobactam or meropenem from the MERINO study academic.oup.com/cid/advance-ar… Nice work @Hendonet @padstamundo @davidantibiotic

This paper from @Hendonet @UQMedicine helps further our understanding of the @MerinoTrial - bottom line, MIC matters but so does the way you test and the #AMR genes that define the phenotype

Exciting webinar from ⁦@UQ_News⁩ & ⁦@CHUNimes⁩ on new advances in #antimicrobial susceptibility testing and reporting...stellar panel of Profs Turnidge, Lavigne & Kahlmeter. Thanks to ⁦@CRE_REDUCE⁩ ⁦@Hendonet⁩ ⁦@padstamundo⁩ hosted at #UQCCR

Join Jason Roberts, Andrew Henderson, Jean-Philippe Lavigne, Gunnar Kahlmeter & John Turnidge for a webinar on antimicrobial susceptibility testing & hear from experts on the European Committee on AST (EUCAST). Please register here bit.ly/3dfGquY

Our review in JAC on the use of oral 3GC/BLIs for ESBL urinary tract infections @davidantibiotic @padstamundo @Hendonet academic.oup.com/jac/advance-ar…

@evanbursle @padstamundo @padstamundo so good. Might need to do some editing again of your next infect control course lecture

@padstamundo Thanks for this! @Hendonet

Since everyone’s doing this .. here is #MeAt20 taken at Koh Tao Divers in 1994 .. all that hair seems to have since migrated to my face

Safety and tolerability determined for monoclonal antibody treatment for #hendravirus in healthy human volunteers ~ Prof Geoffrey Playford @qldhealthnews @UQ_News #veterinaryscience #medicalresearch #clinicaltrials

NEW🔥🔥 Review Article @davidantibiotic @Hendonet @padstamundo Current evidence for therapy of ceftriaxone-resistant Gram-negative bacteremia. #IDtwitter A must read article. #medtwitter ENJOY pdfs.journals.lww.com/co-infectiousd…

@DrToddLee @padstamundo @davidantibiotic @Hugh_Murray_ @syctong @Josh_S_Davis We also only looked at vitek S strains, but I think that is the question that clinicians are most interested in: if the vitek calls it susceptible, can the lab exclude penicillinase in order to confidently treat the patient with benzylpenicillin.

@Hendonet @padstamundo @davidantibiotic @Hugh_Murray_ @syctong @Josh_S_Davis So the net difference per 1000 tested patients is that vitek followed by disc would increase detection by 15 cases vs vitek followed by nitrocefin? (Assuming vitek sensitivity is 93% to exclude blaZ as your prevalence was 7.2%)

biorxiv.org/content/10.110…. @padstamundo @davidantibiotic screening for Penicillinase in PSSA. Further proof for enrolling patients in PSSA BSI trials. @Hugh_Murray_ @syctong @Josh_S_Davis

@DrToddLee @padstamundo @davidantibiotic @Hugh_Murray_ @syctong @Josh_S_Davis We are sequencing all blaZ detected strains. There seemed to be two phenotypic distinct populations - disk size < 26 indicating an expressed penicillinase enzyme (perhaps slowly induced) and those with size > 26 in the WT distribution that might only express a basal amount.

@DrToddLee @padstamundo @davidantibiotic @Hugh_Murray_ @syctong @Josh_S_Davis Prevalence of penicillin susceptible by vitek in our region is about 12-14% depending on specimen site. Nitrocefin and disk testing seemed to perform equally for different vitek MICs but numbers start to get low when you stratify by this.

@DrToddLee @padstamundo @davidantibiotic @Hugh_Murray_ @syctong @Josh_S_Davis All good points and lots of questions! First thing - I have never seen a published case of penicillin failure for PSSA due to mis-identification of penicillin resistance. Several other drug-bug combos have as many issues with false susceptibility (if not more)