ESCMID 2026: Highlights from Day 1

High-Risk Clones and Resistance Gene Convergence Among Community Uropathogens in India: Genomic Evidence from a Nationwide Study

Presenter: S. Pundir.

This multicentric cross-sectional study evaluated the prevalence, antimicrobial susceptibility, and genomic resistance determinants of uropathogens in community settings across India over 1.5 years. Among 6,009 patients with suspected UTI, significant bacteriuria was detected in 11.8% (711 isolates). The most common pathogens were Escherichia coli (63%, 448/711) and Klebsiella pneumoniae (15.7%, 112/711). In E. coli, multidrug resistance (MDR) and ESBL production were observed in 64.5% and 65.4% of isolates, respectively. High-risk clones ST131 (25%) and ST1193 (10.7%) were identified, frequently carrying plasmid replicons IncFIB (63.1%) and IncFIA (52.6%), and the transposon Tn2680 (46.6%).

In K. pneumoniae, MDR and ESBL prevalence were 39.2% and 56.2%, with ST15, ST16, and ST231 each accounting for 20% of isolates. Multiple β-lactamase genes were detected, including blaNDM-5 (33.3%), blaOXA-1 (53.3%), blaCTX-M-15 (60%), and blaTEM-4 (60%). Notably, four ESBL-positive isolates co-harbored blaCTX-M-15 and blaOXA-232 on ColKP3 plasmids.

Overall, the study highlights a high burden of MDR and ESBL-producing uropathogens with widespread dissemination of high-risk clones and co-existing resistance genes in community settings.

Is the High Prevalence of Antibiotic Resistance in LMICS the Result of Local or Global Emergence?

Presenter: Sepideh Benvari

This interdisciplinary genomic study investigated the origins of antibiotic resistance (ABR) in Escherichia coli causing urinary tract infections across East Africa, using 857 isolates from Kenya, Tanzania, and Uganda. Pangenome analysis with a global reference dataset (n=2,464) showed that 42% of East African isolates carried more ABR categories than expected for their cluster, indicating local emergence of resistance. Among dominant lineages (ST131, ST10, ST69, ST1193; n=268), ancestral state reconstruction identified 1,463 ABR determinants, of which 20% had emerged locally, and 46% of isolates carried at least one locally emerged determinant.

The findings indicate that both global dissemination of resistant lineages and local emergence contribute to the high burden of resistance. Factors associated with local emergence included male sex, lack of access to a flush toilet, lower educational attainment, recruitment from primary care, and household contact with manure.

The study highlights the combined role of global and local drivers in shaping ABR patterns, with social and environmental factors contributing to locally emerged resistance.

Caste-Based Disparities and AMR Risks

Presenter: Srishti Goel

This study examined the role of caste-based inequalities in shaping antimicrobial resistance (AMR) risk in South Asia, with a focus on India. A conceptual framework was developed to illustrate how caste-based discrimination influences infection risk, antibiotic use, and access to healthcare. Descriptive analyses using National Family Health Survey (NFHS-5, 2019–2021) data assessed differences across caste groups in key AMR-related determinants, including water, sanitation, and hygiene (WASH), nutritional status, and prevalence of sexually transmitted diseases and infections (STDs/STIs).

Findings showed that lower caste households had reduced access to WASH facilities, poorer nutritional status, and higher reported incidence of STDs/STIs. These disparities were more pronounced among women from marginalized caste groups.

In conclusion, the study highlights how social, economic, and structural inequalities contribute to differential AMR risk, emphasizing the need for intersectional and interdisciplinary approaches to address these disparities.

Steroid-Linked Invasive Fungal Infections After CAR-T: Insights from a National Australian Cohort

Presenter: Gemma Reynolds

This national, multicentre cohort study evaluated the incidence and risk factors for invasive fungal infections (IFI) in adults receiving CD19-directed CAR-T therapy for aggressive lymphoma (2019–2023; follow-up to March 2025). A total of 291 patients (median age 64 years) were included. Seventeen IFIs occurred in 17 patients (5.8% of the cohort; 11% of microbiologically confirmed infections). IFIs developed at a median of 122 days post-infusion (IQR: 25–263), with 29% occurring ≥6 months. Infection rates were significantly higher within the first 30 days compared to later periods (0.14 vs 0.007 per 100 patient-days; IRR=0.05, p=0.003). Common pathogens included pulmonary aspergillosis (47%), Candida bloodstream infections (35%), and Pneumocystis jirovecii (6%). IFIs occurred despite antifungal prophylaxis in 29% of cases, and all were grade ≥3, with three fatalities.

In multivariable competing-risk Cox regression, higher cumulative dexamethasone exposure within 30 days post-infusion was independently associated with IFI risk (HR 1.003, 95% CI: 1.002–1.004; p<0.001). A threshold of 56 mg dexamethasone-equivalent predicted IFI (HR 6.6, 95% CI: 1.6–27.1; AUC 0.71; p=0.015).

Overall, IFIs were infrequent but clinically significant, with early steroid exposure identifying a high-risk subgroup.

"No Breakpoints? No Problem!" Evaluating Gentamicin Perioperative Prophylaxis for Pseudomonas Aeruginosa Asymptomatic Bacteriuria Before Urological Surgery

Presenter: Niamh Reidy

This retrospective study evaluated the effectiveness of perioperative gentamicin prophylaxis in patients with asymptomatic bacteriuria undergoing urological procedures (January 2024–September 2025), including those with Pseudomonas aeruginosa and Enterobacterales. Patients were grouped as: P. aeruginosa with gentamicin MIC <4 mg/L (n=57), gentamicin-susceptible Enterobacterales (n=69), and gentamicin-resistant gram-negatives (n=16). Rates of postprocedural systemic inflammatory response syndrome (SIRS) were similar between P. aeruginosa and gentamicin-susceptible Enterobacterales groups (3.5% vs 4.3%; OR 0.80; p=1.00). Unplanned ICU admissions were also comparable (1.75% vs 1.4%). Culture-positive postoperative urine samples occurred in 26.3% vs 29.0% (OR 0.88; p=0.84), and symptomatic urinary or surgical site infections within 3 months occurred in 10.5% vs 17.4% (OR 0.56; p=0.32).

Postoperative bacteriuria was significantly higher in the gentamicin-resistant group compared to the P. aeruginosa group (62.5% vs 26.3%; OR 4.7; p=0.015). Gentamicin resistance among postoperative isolates remained low in targeted prophylaxis groups.

In conclusion, gentamicin prophylaxis showed comparable outcomes in P. aeruginosa (low MIC) and susceptible Enterobacterales, while use in resistant organisms was associated with worse outcomes.

ESCMID 2026, 17-21 April, Munich.