In Vitro Activity of Ceftaroline Against Multidrug-Resistant Bacteria in Niger: Resistance Trends and Clinical Implications

Multidrug-resistant bacteria, including extended-spectrum β-lactamase-producing Enterobacterales and methicillin-resistant Staphylococcus aureus, pose a major therapeutic challenge in Niger.Ceftaroline, a fifth-generation cephalosporin, offers potential activity against these pathogens.This study aimed to evaluate the in vitro activity of ceftaroline against multidrug-resistant bacteria isolated in Niger and to identify factors associated with resistance.A prospective cross-sectional study was conducted from January to August 2025.A total of 212 non-duplicate multidrugresistant isolates (160 extended-spectrum β-lactamase-producing Enterobacterales, 52 methicillin-resistant Staphylococcus aureus) were tested using the disk diffusion method.Logistic regression was used to identify factors independently associated with ceftaroline resistance.The overall resistance rate to ceftaroline was 69.3% (147/ 212).extended-spectrum β-lactamase-producing Enterobacterales isolates exhibited a very high resistance rate (80.6%), whereas methicillin-resistant Staphylococcus aureus (MRSA) isolates showed lower resistance (34.6%).In multivariate analysis, extended-spectrum β-lactamase-producing Enterobacterales phenotype (Odds Ratio=5.03;95% Confidence Interval=2.13-11.83),concurrent resistance to aminoglycosides (Odds Ratio=2.55;95% Confidence Interval=1.21-5.33),fosfomycin (Odds Ratio=3.42;95% Confidence Interval=1.01-11.50),and cotrimoxazole (Odds Ratio=3.97;95% Confidence Interval=1.20-13.02)were significant factors independently associated with ceftaroline resistance.This first study conducted in Niger reveals an alarming rate of in vitro resistance to ceftaroline among multidrugresistant bacteria, primarily extended-spectrum beta-lactamase-producing Enterobacterales.Ceftaroline should not be used empirically for suspected infections with these pathogens in this context.Its use against methicillin-resistant Staphylococcus aureus must be guided by susceptibility testing.These data call for revisions to therapeutic protocols and reinforcement of antimicrobial stewardship strategies.