1270. Molecular Characterization of Carbapenemase Producing Enterobacterales, Acinetobacter spp. and Pseudomonas spp. in Nosocomial and Community-acquired Clinical Isolates in Bogota, Colombia

Abstract Background Antimicrobial resistance (AMR) in low-income and middle-income countries (LMICs) is a public health problem. AMR is a concerning problem in Gram-negative bacteria such are Enterobacterales, which are frequently carbapenem-resistant pathogens (CRP), and few therapeutic options are available. However, scarce data is known regarding the clinical, molecular characteristics, and clinical outcomes of patients infected with carbapenem-resistant pathogens in LMICs. Thus, this study will attempt to bring novel data in these regards. Methods This is a retrospective cohort study conducted in two reference hospitals in Colombia, South America. All consecutive patients infected with CRPs between 2017 and 2021 were included. Clinical data were gathered by retrospective chart review. Bacterial pathogens and antibiotic susceptibility were prospectively identified and stored by each hospital. Molecular characterization was performed by PCR in isolated bacteria. Results A total of 220 patients were included. The mean (SD) age was 60.6 (18.4) years, and 32% (71/220) were female. The most frequently identified CRPs were Pseudomonas aeruginosa (85/220, 39%) and Klebsiella pneumoniae (81/220, 37%). CRPs were most frequently identified in urine, blood, and respiratory samples (Figure 1). Community-acquired infections were frequently diagnosed in patients infected with CRPs in our study (73% [161/220]), and most of the patients were admitted to the ICU (163/220, 74%). The in-hospital mortality rate was 28% (62/220) and 38% (62/163) in ICU admitted patients. PCR was carried out in 105 CRP; KPC (69%, 73/105) and VIM (37%, 39/105) were the most frequently identified mechanisms. Of the K. pneumoniae isolates with PCR assessment, 94% (33/35) had KPC and 3% (1/35) had VIM. In contrast, in P. aeruginosa isolates with PCR assessment, 53% (29/54) had KPC and 59% (32/54) had VIM. Seven (13%) patients infected with P. aeruginosa had both KPC and VIM genes identified. Conclusion The most frequently identified carbapenem-resistant pathogens in these two Colombian reference hospitals were P. aeruginosa and K. pneumoniae, with high mortality rates. KPC was the most commonly identified mechanism of carbapenem resistance in our cohort. Disclosures All Authors: No reported disclosures

Most cases (55%) were encountered during the months of spring and summer, which have warmer temperatures and seasonal heavy rains. Tropical storms caused significant flooding in the Galveston Bay area and Southeast Texas during the summer of 2015, which interestingly coincides with the high number of cases. However, following Hurricane Ike in 2008 or Hurricane Harvey in 2017, the number of cases did not significantly increase.

Conclusion.
Aeromonads are emerging pathogens that cause mainly intraabdominal and skin and soft tissue infections. Their incidence is seasonal (55% cases in spring and summer) and it is associated with water exposure in more than half of those with traumatic wound infections. In subjects with specific risk factors, the use of carbapenem-sparing strategies, such as 3 rd or 4 th generation cephalosporins, fluoroquinolones or TMP-SMX, may improve outcomes.
Disclosures. Background. Antimicrobial resistance (AMR) in low-income and middle-income countries (LMICs) is a public health problem. AMR is a concerning problem in Gram-negative bacteria such are Enterobacterales, which are frequently carbapenem-resistant pathogens (CRP), and few therapeutic options are available. However, scarce data is known regarding the clinical, molecular characteristics, and clinical outcomes of patients infected with carbapenem-resistant pathogens in LMICs. Thus, this study will attempt to bring novel data in these regards.
Methods. This is a retrospective cohort study conducted in two reference hospitals in Colombia, South America. All consecutive patients infected with CRPs between 2017 and 2021 were included. Clinical data were gathered by retrospective chart review. Bacterial pathogens and antibiotic susceptibility were prospectively identified and stored by each hospital. Molecular characterization was performed by PCR in isolated bacteria.

Conclusion.
The most frequently identified carbapenem-resistant pathogens in these two Colombian reference hospitals were P. aeruginosa and K. pneumoniae, with high mortality rates. KPC was the most commonly identified mechanism of carbapenem resistance in our cohort.
Disclosures. All Authors: No reported disclosures

Session: P-72. Resistance Mechanisms
Background. Community-acquired bacterial pneumonia (CABP) is a frequent cause of patient morbidity and mortality. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are frequent etiologic agents of CABP. Ceftaroline fosamil is a parenteral cephem approved for treatment of patients with CABP caused by S. pneumoniae (including cases with concurrent bacteremia), methicillin-susceptible Staphylococcus aureus (MSSA), H. influenzae, and some species of Enterobacterales. In this study we report the in vitro activity of ceftaroline and comparators against isolates from community-acquired respiratory tract infections (CARTI) collected through a global surveillance program.

Results Table
Conclusion. Ceftaroline demonstrated potent in vitro activity against current pathogens associated with CABP from a global collection.
Disclosures Background. Cefiderocol (CFDC) is a novel siderophore-conjugated cephalosporin with broad activity against aerobic, nonfastidious Gram-negative bacteria. CFDC and comparator activities were analyzed against molecularly characterized A. baumannii-calcoaceticus complex (ACB) and P. aeruginosa (PSA), as a part of the SENTRY Antimicrobial Surveillance Program in the USA.
Methods. 248 ACB and 1,069 PSA were consecutively collected from 30 sites in 2020. Susceptibility was performed by broth microdilution and CFDC testing used iron-depleted media. FDA and CLSI breakpoints were used for CFDC. CLSI criteria were applied to comparators, except for imipenem-relebactam (IMR) that used FDA breakpoints. ACB and PSA with imipenem and/or meropenem (MER) MIC ≥4 μg/mL or ceftazidime (CAZ) and/or cefepime MIC ≥16 μg/mL were subjected to next-generation genome sequencing for screening for acquired extended-spectrum β-lactamase (ESBL) and carbapenemase genes.
Conclusion. Acquired ESBL and carbapenemase genes remained rare among multidrug-resistant PSA in USA hospitals, whereas acquired bla OXA carbapenemase were prevalent among ACB. CFDC showed potent activity against PSA subsets, as well as across molecularly characterized subsets of ACB, where treatment options were limited.