Antibiotic Resistance Pattern of Acinetobacter baumannii Strains Isolated from Different Clinical Specimens and Their Sensibility Against Bioactive Molecules Produced by Actinobacteria

Acinetobacter baumannii frequently targets the most vulnerable hospitalized patients, especially in intensive care units. Bacteremia, nosocomial pneumonia and surgical wound infections caused by A. baumannii have a higher mortality compared to other nosocomial pathogens. The severity of the diseases caused by this microorganism is accentuated by its resistance to many antibiotics currently used in the world. In this context, we undertook to isolate several A. baumannii strains from various samples collected in the Beni Messous University Hospital Center, Algiers (Algeria), to determine the antibiotic resistance profile of these strains and to evaluate the antagonistic potential of some actinobacterial strains against A. baumannii. Nineteen A. baumannii strains were isolated and identified. The predominant number of strains isolated from pulmonary samples (36.84%) and from the intensive care unit (57.89%) was A. baumannii. All A. baumannii strains were sensitive to colistin but exhibited high resistance to 11 other antibiotics tested. Of the 19 strains, 15 were metallo-β-carbapenemase producers, 10 were cephalosporinase, and three were extended-spectrum β-lactamases (ESBL) producers. Of 59 strains of actinobacteria tested, 19 (32.20%) showed activity against at least one strain of A. baumannii, the highest activity being detected in strains belonging to the genus Saccharothrix (or related genera). However, Streptomyces sp. WAB9 had the widest spectrum of activity. Based on the obtained results, colistin remains the unique antibiotic which inhibits the growth of all A. baumannii strains, and some actinobacterial strains also present an alternative source of new molecules with strong bioactivities against multidrug-resistant A. baumannii strains.