The COVID-19 pandemic has exacerbated the global antimicrobial resistance (AMR) crisis. Consequently, it is more urgent than ever to prioritize AMR containment and support countries in improving the detection, characterization, and rapid response to emerging AMR threats. We conducted a prospective, multicenter study to assess the prevalence of carbapenemase-producing Enterobacterales in infectious processes in Argentina during the post-COVID-19 pandemic period and explore therapeutic alternatives for their treatment (RECAPT-AR study). Methods: A total of 182 hospitals participated by submitting Enterobacterales clinical isolates to the National Reference Laboratory (NRL) during the first three weeks of November 2021. Inclusion criteria were defined as an ertapenem MIC ≥ 0.5 mg/L, a zone diameter ≤ 22 mm. Carbapenemase genes and those coding for major extended-spectrum β-lactamases were molecularly characterized using multiplex PCR at the NRL. Antibiotic susceptibility testing followed international standards (CLSI and EUCAST). Results: The NRL analyzed 821 Enterobacterales isolates. Metallo-β-lactamase (MBL, 42.0%) and KPC (39.8%) accounted for 81.8% of carbapenemases, followed by OXA-163 (7.4%), a variant of OXA-48 with additional activity against extended-spectrum cephalosporins, and enzyme combinations (8.3%). These combinations included NDM plus KPC (3.4%), OXA-163 plus KPC (2.4%), and OXA-163 plus NDM (2.1%). Klebsiella pneumoniae was the main species recovered, representing 76% of the isolates. According to the carbapenemase classes or combinations, tigecycline exhibited a susceptibility range of 33–83%, fosfomycin 59–81%, colistin 27–78%, and amikacin 17–81%. Ceftazidime-avibactam (CZA) and imipenem-relebactam (IMR) showed 92% and 98% susceptibility against serine carbapenemases, respectively. Meanwhile, aztreonam-avibactam (AZA) exhibited 96–98% susceptibility against all carbapenemase classes. Conclusions: A new epidemiological landscape has emerged, characterized by the equivalent circulation of NDM and KPC. K. pneumoniae remains the primary species responsible for their dissemination. The co-production of carbapenemase combinations, particularly KPC plus NDM, was confirmed, mainly in K. pneumoniae. High activity was observed for AZA against MBLs and for CZA and IMR against KPC and OXA-163 carbapenemases.

The introduction of pneumococcal conjugate vaccination (PCV) into the Argentinian Childhood National Immunization Program in 2012 marked a significant milestone in public health. Our study aims to assess the impact of this intervention on pneumococcal meningitis cases, serotype distribution, and antimicrobial resistance among pediatric populations from 2013 to 2023. Specifically, we compared the early post-PCV period (2013–2014) to the late post-PCV period (2022–2023). A total of 333 pneumococcal isolates were analyzed between 2013 and 2023. Gold standard pneumococcal serotyping was performed to identify the serotypes associated with infection in children < 6 years in Argentina, and the agar dilution method was carried out to determine their profiles to antimicrobial agents. Our findings underscore the importance of PCV implementation, revealing notable shifts in pneumococcal epidemiology over the study period. The proportions of serotypes 1 (6.7% to 0.0%), 5 (5.6% to 0.0%), and 14 (7.8% to 1.8%) decreased, whereas the proportions of serotypes 10A (3.3% to 10.7%), 15B/C (2.2% to 10.7%), and 24B (0.0% to 8.9%) increased. The top five rated serotypes in the 2022–2023 period were serogroup 24 (21.4%), 10A (10.7%), 15B/C (10.7%), 23B (7.1%), and 12F (5.4%). Regarding antimicrobial resistance, we found that a total of 115/311 isolates (37%) were not suceptible to penicillin, and 2.9% were not suceptible to cefotaxime. Twenty-five percent of the isolates were microbial drug resistant, with resistance to penicillin, erythromycin, tetracycline/doxicycline, and/or cotrimoxazol. Among the PCV13 serotypes, 19A remained the most commonly associated with MDR. The non-PCV13 serotypes, particularly 24F, 24A, and 24B, were prevalent among MDR isolates. The observed trends demonstrate the need for the continued expansion of pneumococcal vaccination policies, including consideration for vaccines offering enhanced indirect protection, thereby extending benefits beyond the pediatric population to encompass adults as well. Such strategies are pivotal in reducing the burden of pneumococcal disease and safeguarding public health.

The introduction of pneumococcal conjugate vaccination (PCV) into the Argentinian Childhood National Immunization Program in 2012 marked a significant milestone in public health. Our study aims to assess the impact of this intervention on pneumococcal meningitis cases, serotype distribution, and antimicrobial resistance among paediatric populations from 2013 to 2023. Specifically, we compared the early post-PCV period (2013–2014) to the late post-PCV period (2022–2023). A total of 333 pneumococcal isolates were analyzed between 2013 and 2023. Gold standard pneumococcal serotyping was performed to identify the serotypes associated with infection in children < 6 years in Argentina and agar dilution method was carried out to determine their profiles to antimicrobial agent. Our findings underscore the importance of PCV implementation, revealing notable shifts in pneumococcal epidemiology over the study period: proportion of serotypes 1 (6.7% to 0.0%), 5 (5.6% to 0.0%) and 14 (7.8% to 1.8%) decreased, whereas proportion of serotypes 10A (3.3% to 10.7%), 15B/C (2.2% to 10.7%) and 24B (0.0% to 8.9%) increased The top five rated serotypes in the 2022-2023 period were serogroup 24 (21.4%), 10A (10.7%), 15B/C (10.7%), 23B (7.1%) and 12F (5.4%). Regarding antimicrobial resistance, we found that a total of 115/311 isolates (37%) were non suceptible to penicillin, 2.9% to cefotaxime. Twenty five percent of the isolates were microbial drug resistant, with resistance to penicillin, erythromycin, tetracycline/doxicycline and/or cotrimoxazol. Among PCV13 serotypes, 19A remained the most commonly associated with MDR. Non-PCV13 serotypes, particularly 24F, 24A, and 24B, were prevalent among MDR isolates. The observed trends advocate for the continued expansion of pneumococcal vaccination policies, including consideration for vaccines offering enhanced indirect protection, thereby extending benefits beyond the paediatric population to encompass adults as well. Such strategies are pivotal in reducing the burden of pneumococcal disease and safeguarding public health.