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Posts by David Helekal

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Great discussion with @billhanage.bsky.social and the audience at #ESCMIDGlobal2026 during our session “Pathogens and people: modelling epidemics for preparedness”. Strong focus on how to improve preparedness in collaboration with public health institutes - lots to take forward.

3 days ago 6 3 1 0

Ian Braga, Lucas Wardil, Ricardo Martinez-Garcia: Fixation probabilities for multi-allele Moran dynamics with weak selection https://arxiv.org/abs/2604.12004 https://arxiv.org/pdf/2604.12004 https://arxiv.org/html/2604.12004

1 week ago 1 2 0 1
Image of lab scientist with test tubes.

Image of lab scientist with test tubes.

The European Commission will invest $34.7 million in the two public-private partnerships to boost the pipeline for new antibiotics and other AMR medical countermeasures.

Read more: ow.ly/Sap850YFgir

2 weeks ago 29 10 2 1
Job Details

We (with @yanwong.bsky.social) are advertising a 3 year postdoc position for a project on ARG inference and methods! Based at Oxford stats. Closing date noon 7 April, full details at my.corehr.com/pls/uoxrecru...

4 weeks ago 7 8 0 1

🚨 New pre-print! 🚨 In the largest study of its kind to-date, we investigate the ecological and evolutionary mechanisms driving within-patient evolution of antimicrobial resistance (AMR). Read here:
www.biorxiv.org/content/10.6... , and follow along with this thread, discussing our findings (1/21)

2 months ago 64 33 2 3

We're also happy to see a second paper out today, led by Nicola de Maio, which develops methods to identify and account for mutation rate variation and recurrent errors.

www.nature.com/articles/s41...

2 months ago 13 5 2 0
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Ian Roberts published his first paper "Bayesian Inference of Pathogen Phylogeography using the Structured Coalescent Model" with me, Jere Koskela and Xavier Didelot. We describe an efficient reversible jump MCMC method for inference for the structured coalescent. journals.plos.org/pl...

2 months ago 11 1 1 0

Now published: our work using phylodynamics from surveillance data to quantify and experimentally validate the fitness impact of antibiotic resistance determinants & how this changes with patterns of antibiotic use: www.nature.com/articles/s41...

2 months ago 66 31 1 0

Very happy to have had the opportunity to contribute to this work. Thanks to Robin Thompson for leading, the amazing team of co-authors and the INI for hosting us.

2 months ago 15 8 0 0
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✅ Say: "My manuscript has been metropolised"
❌ Don't say: "My manuscript has been rejected and so I've sent it to MDPI"

9 months ago 1 0 1 0

Now out in NEJM. Kudos to @dhelekal.bsky.social and @tatumdmortimer.bsky.social : www.nejm.org/doi/10.1056/...

9 months ago 24 13 1 1
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Performance of deep-learning-based approaches to improve polygenic scores - Nature Communications Polygenic scores aim to capture genetic risk but may miss nonlinear genetic and environmental interactions. Here, the authors show that neural networks detect limited nonlinearity and do not outperfor...

www.nature.com/articles/s41...

9 months ago 3 0 0 0
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ECR Data Visualisation Workshop Please complete this application to attend the Data Viz workshop. This event will be held at the 2025 STI & HIV World Congress in Montreal, Canada on Wednesday, July 30th from 11:30-13:30. Effective...

If you are an early career research attending @stihiv2025.org and interested in learning more about data visualization in R, @odileharrison.bsky.social , Sim Dabee, and I are organizing a workshop during the conference (11:30am-1:30pm on Wednesday). Register here: forms.gle/e4UL1NG62PUD...

9 months ago 5 5 0 0

A fun conversation with Carl this afternoon about his excellent book AIR-BORNE--the recording is available at the HSPH youtube site: www.youtube.com/user/Harvard...

9 months ago 20 3 0 0
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Outbreak of Ceftriaxone-Resistant <em>Salmonella enterica</em> Serovar Typhi, Bangladesh, 2024 Ceftriaxone-Resistant <em>Salmonella</em> Typhi, Bangladesh

One ceftriaxone-resistant #typhoid case last year set us on a path that is now live on Emerging Infectious Diseases.
47 cases in months, resistance rose from 0 to 5%. We spoke with patients, sequenced samples. 4.3.1.2.B1 lineage+blaCTX-M-15 on pCROB1. #AMR #PublicHealth
wwwnc.cdc.gov/eid/article/...

9 months ago 3 6 1 0

Looking forward to my visit @ccdd-hsph.bsky.social!

1 year ago 3 2 0 0

(10/10) Work with @tatumdmortimer.bsky.social & @yhgrad.bsky.social

1 year ago 2 0 0 0
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Emergence of Extensively Drug-Resistant <em>Neisseria gonorrhoeae,</em> France, 2023 Extensively Drug-Resistant <em>Neisseria gonorrhoeae</em>

(9/10) As N. gonorrhoeae strains carrying high-level cephalosporin resistance on a tetM positive background have been emerging globally wwwnc.cdc.gov/eid/article/..., the evident strength of selection for tetM may have created a favorable environment for their expansion in the US.

1 year ago 3 0 1 0

(8/10) This raises concern for genetic hitchhiking, whereby alleles that may be neutral or deleterious on their own actually increase in frequency due to their presence in lineages that carry another gene or allele that’s beneficial.

1 year ago 3 0 1 0
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(7/10) The number of major N. gonorrhoeae lineages carrying tetM also increased from one before 2020 that accounted for ~40% of all tetM+ isolates to 4 after 2020 that collectively accounted for ~80% of all tetM+ isolates. Two of these lineages carry penA variants that increase cephalosporin MICs.

1 year ago 2 0 1 0
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Doxycycline to prevent bacterial sexually transmitted infections in the USA: final results from the DoxyPEP multicentre, open-label, randomised controlled trial and open-label extension Doxy-PEP was effective in reducing bacterial STIs in this population of men who have sex with men and transgender women, including during an open-label extension when doxy-PEP efficacy was known. Doxy...

(6/10) This is consistent with a recent report out of Seattle, showing an increase in resistance in N. gonorrhoeae and an increase in S. aureus tetracycline resistance in those on doxy-PEP: academic.oup.com/cid/advance-... and www.thelancet.com/journals/lan...

1 year ago 2 0 1 0
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(5/10) By May 2024, the estimated proportion of isolates carrying tetM skyrocketed to ~35%, suggesting a large selective pressure for doxycycline resistance. The rise seems most pronounced in HHS regions 9 and 10.

1 year ago 3 1 1 0
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Drug-Resistant Gonorrhea This page explains drug-resistant gonorrhea, changing treatments, and current challenges

(4/10) To investigate the impact of the increased doxy use, we analyzed a collection of over 14000 N. gonorrhoeae genomes spanning 2018-mid 2024, collected and sequenced through CDC surveillance efforts -- GISP, eGISP, SURRG www.cdc.gov/gonorrhea/hc....

1 year ago 3 0 1 0
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Effects of doxycycline post-exposure prophylaxis for prevention of sexually transmitted infections on gonorrhoea prevalence and antimicrobial resistance among men who have sex with men in the USA: a m... Doxycycline post-exposure prophylaxis (PEP) has been shown to be efficacious for the prevention of bacterial sexually transmitted infections, but resistance implications for Neisseria gonorrhoeae rema...

(3/10) This is especially relevant for N. gonorrhoeae. In 2018, an estimated 10% of isolates carried the plasmid-borne gene tetM, which confers high-level tetracycline resistance (MIC ≥ 16 µg/mL) pmc.ncbi.nlm.nih.gov/articles/PMC....

1 year ago 3 0 1 0

(2/10) Over the past few years, the use of doxycycline to treat bacterial STIs has gone up in the US. Doxy became the recommended treatment for chlamydia (2020), it was used for syphilis treatment during bicillin shortages, and doxy-PEP was rolled out. What’s the impact on resistance?

1 year ago 2 0 1 0
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(1/10) New preprint: Expansion of tetM-carrying Neisseria gonorrhoeae in the US, 2018-2024; Link: www.medrxiv.org/content/10.1...

1 year ago 14 7 1 1

Work with @tatumdmortimer.bsky.social & @yhgrad.bsky.social

1 year ago 0 0 0 0
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Emergence of Extensively Drug-Resistant <em>Neisseria gonorrhoeae,</em> France, 2023 Extensively Drug-Resistant <em>Neisseria gonorrhoeae</em>

(9/10) As N. gonorrhoeae strains carrying high-level cephalosporin resistance on a tetM positive background have been emerging globally wwwnc.cdc.gov/eid/article/..., the evident strength of selection for tetM may have created a favorable environment for their expansion in the US.

1 year ago 0 0 1 0

(8/10) This raises concern for genetic hitchhiking, whereby alleles that may be neutral or deleterious on their own actually increase in frequency due to their presence in lineages that carry another gene or allele that’s beneficial.

1 year ago 1 0 1 0