Nationwide Genomic Surveillance of Klebsiella Pneumoniae in the United States from 2010-2020– Melissa Martin
A retrospective analysis of nearly 3,000 resistant K. pneumoniae isolates in the hospital system. The top three lineages (sequence types) found during the 10-year period surveillance were ST-45, ST-258, and ST-307. The prevalence of carbapenemase-producing isolates were very low (<5%). They were found throughout the phylogeny, but mainly in ST-258 and those isolates were normally carrying KPC-3 and KPC-2. An NDM carrying K. pneumoniae was seen to be rare in the surveillance. The antibiotic susceptibility testing of all K. pneumoniae isolates showed that lineages 258, 147 and 307 had highly resistant profile. In several parts of the world, KPC carrying 258 is a major problem, especially with nosocomial outbreaks. However, in this surveillance, outbreak of ST-258 carrying carbapenemase was rarely found. Out of 7 nosocomial outbreak clusters, only 5 carried KPC clone. In the outbreak cluster detection of ST-45, 258, and 307, ST-45 caused most nosocomial outbreaks.
AMR Register: Creation of a New, Freely Accessible Platform for Antimicrobial Susceptibility Data Sharing - Bruce Alevogt
This initiative is by multiple pharmaceutical companies collectively sharing raw surveillance data with the research community on a single platform. This database contains 970,000 isolates, collected from 85 countries from the period of 2004 to 2021. There are 574 pathogens (aerobic, anaerobic, fungal, and mycobacterium) tested against 74 drugs. The purpose is to help developmental programs, identify areas of future medical needs, and to meet regulatory requirements. This is high quality MIC data and type of researches uses by the investigators have been to inform local policies, to strengthen understanding of global emergence, to support drug developments and to develop drug-resistance profile specific drugs. The data can be accessed through the website searchamr.vivli.org for developmental projects.
Antimicrobial Resistance in Invasive Streptococcus Pyrogens: England 2016-2022 – Rebecca Guy
Invasive group A Streptococcus (IGAS) is notifiable. Susceptibility data was collected on the IGAS isolates and combined with emm type. Between 2016 and 2021, increasing trend in IGAS AMR was noticed to tetracycline and partially to clindamycin and erythromycin. Different emm types were identified from the invasive isolates with changing trend in dominance over the years. emm types 33.0, 77.0, and 108.1 were strongly associated with tetracycline resistance. emm 89.0 showed variable resistance over time to tetracycline and got more resistance over the years. It is important to do full antibiogram and monitoring of patients, especially those with penicillin allergy. Monitoring AMR mechanisms and looking at the genome sequencing would be essential to overcome the challenges of treatment.
Activity of Imipenem/relebactam and Comparators Against Clinical MDR and DTR Pseudomonas Aeruginosa Isolates: SMART United States 2019-2021– Meredith Hackel
24 clinical labs in the US collected up to 250 pathogens from patients with bloodstream infections, intraabdominal infections, LRTI and UTI. By length of stay, isolates collected from patients admitted for 2 days or more showed 21% P. aeruginosa opposed to 16% in those admitted for <2 days. But it would be difficult to report whether these were hospital-acquired or community-acquired infection. In terms of patients in the ICU vs. non-ICU wards, a greater prevalence of P. aeruginosa was seen compared to other pathogens in the ICU than the non-ICU wards. In patients with presumed hospital-acquired infection, susceptibility was 3-6% lower as compared to isolates from patients who were there for 2 days or less. In patients in ICU vs. non-ICU wards, there was 2-4% decrease in susceptibility among isolated from the ICU as opposed to those from the non-ICU. In isolates from ≥48 hours, an increase in MDR and DTR was noticed. In ICU vs. non-ICU wards, there was an increase in MDR phenotype but DTR was about the same. Imipenem/relebactam maintained at least 50% susceptibility rates among MDR isolates regardless of ward or length of stay. And in DTR, ≥35% isolates, regardless of ward or length of stay, were susceptible to imipenem/relebactam.
Impact of Minor Carbapenemases on Susceptibility to Newly Developed β-lactam/lactamase Inhibitor Combinations in Enterobacterales – Mustafa Sadek
Minor carbapenemase include SME, MncA, IMI and FRI-like enzymes. The aim was to look into the susceptibility of imipenem-relebactam (I-R), meropenem-vaborbactam (MVB) and ceftazidime-avibactam (CZA) against minor carbapenemase-producing enterobacterales. MVB and CZA worked most well against isolates, but I-R showed only moderate activity. Avibactam and vaborbactam showed greater inhibitory activities against the minor carbapenemases than relebactam.
In Vitro Activity of Ceftibuten-avibactam against Enterobacterales from UTIs Collected in the 2022 ATLAS Surveillance Program: A regional Analysis– Meredith Hackel
Addition of avibactam restored the in vitro activity of ceftibuten against global Enterobacterales by 128-fold. CZA activity was consistent across most geographic regions. CZA appears to be a potential oral treatment option for complicated urinary tract infections.
Antibiotic Regimens Including vs. not Including Cefiderocol for the Treatment of Carbapenem-resistant A. baumannii ventilator-associated Pneumonia in ICU – Emanuele Rando
A cohort observational study was conducted that aimed to evaluate whether cefiderocol therapy was associated with 28-day mortality in patients with CRAB-VAP. The FDC group was younger, mostly vaccinated against SARS-CoV-2, and 28-day mortality was less (43%) compared to the non-FDC group (64%). Cefiderocol was associated with 28-day survival, while SOFA score, septic shock and increased age were associated with 28-day mortality. In conclusion, cefiderocol can be a potential FDC for CRAB-VAP in the ICU.
Preliminary Results of an AMR Surveillance Tool in Hospitals in a low-income country: the TSARA Project in Madagascar, 2022 – Christelle Elias
Surveillance provides a good basis to control AMR. Consistent and high-quality dataset are important in clinical decision-making and derive policy actions regarding AMR. The aim was to develop a standardized surveillance tool for AMR with the objective of combining patient data with microbiological and epidemiological data to understand the scope of effect of AMR in Madagascar. Hospitalized patients with bacterial sample were included in this project. During the 8-month study period, more than 1,000 bacterial sample were collected, among which one-third were positive for bacterial culture. In urine culture, 40% were positive for E. coli followed by Enterococcus spp, and almost half of the enterobacteria species were resistant to third-generation cephalosporins. In blood culture, most prominent isolate was negative-coagulase Staphylococci, followed by E. Coli. MRSA accounted for 15% of the positive blood culture. To conclude, it is difficult to collect microbiological data in a low-income country, this surveillance is the first step to have an overview of the bacterial ecology, and the aim is to combine this data to see the antibiotic prescription pattern in Madagascar.
Clostridioides Difficile Resistance to Primary Treatment Antibiotics: Molecular and Phenotypic Epidemiology – Anne Gonzales-Luna
C. difficile is the most common healthcare-associated pathogen in the USA, only three antibiotics are available to treat it – metronidazole, vancomycin, and fidaxomicin. Susceptibility tests are not done to these antibiotics in the clinical setting. There are several mechanisms that can cause resistance, such as gene and RNA mutation. The aim of the study was to explore the molecular and phenotypic epidemiology of reduced C. difficile susceptibility to the three antibiotics in a clinical cohort of patients with CDI. Agar dilution susceptibility testing, fluorescent PCR ribotyping and sanger sequencing of VanSR and nimB regions were done. Reduced susceptibility were characterized by MTZ MIC >0.5 mg/L, VAN MIC >2 mg/L, and FDX MIC >0.5 mg/L. PnimB mutations were present in 83% of isolates representing reduced susceptibility to MTZ. vanG SNP rate was higher (97%) in strains with VAN RS depicting reduced susceptibility to VAN. Overall reduced susceptibility to MTZ was 18%, VAN 29% and FDX 22%. The rates were significantly higher in RT 027 strains (92%, 79%, and 49%, respectively). Half of the cohort showed reduced susceptibility to at least one of these antibiotics and 8% demonstrated reduced susceptibility to all three antibiotics. The rates were higher in RT 027 strains (>95%). Proportion of VAN and FDX reduced susceptibility increased by year. In conclusion, reduced susceptibility is quite common and exploring mechanisms to understanding this is required.
European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) 2023, 15-18 April 2023, Copenhagen, Denmark
