These findings represent the first report of the alarming spread of OXA-23 carbapenemase in A. baumannii in Egyptian intensive care units. The spread of such strains has serious health consequences and requires the application of strict infection control measures.

Background: Urinary tract infections are the most commonly encountered infections in clinics and outpatient settings and are mainly caused by Uropathogenic Escherichia coli (UPEC). Multidrug-resistant bacteria (MDR) have become a major public health threat, worldwide. Objectives: This study aimed to investigate the prevalence of the MDR phenotype, efflux pump-mediated resistance, and the ability for in vitro biofilm formation among UPEC clinical isolates from Egypt. Methods: Uropathogenic E. coli isolates were collected from two Egyptian governorates, identified, and classified to their corresponding phylogenetic group by the polymerase chain reaction (PCR). Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. AcrAB-TolC efflux pump major genes were detected by PCR; efflux pump-mediated resistance was determined by the efflux pump inhibitor microplate-based assay. The ability for in-vitro biofilm formation was also tested. Results:The phylogenetic analysis of the UPEC isolates revealed that most of the isolates belonged to groups B2 and D. The MDR phenotype was detected in 90.8% of UPEC isolates; efflux pump-mediated resistance was detected in all MDR isolates. The acrA, acrB, and tolC were detected in 74.84% of MDR isolates. The ability for in-vitro biofilm formation was recorded in 76.5% of the UPEC isolates. Conclusions:The MDR phenotype and the ability for in-vitro biofilm formation were predominant among UPEC in Egypt. The high prevalence of MDR efflux pumps necessitates the application of new treatment strategies to inhibit this phenomenon.

Urinary tract infections are mainly caused by uropathogenic Escherichia coli (UPEC).

Background: Over the last several years, Acinetobacter has emerged as a leading cause of hospital-acquired infections. Aminoglycosides are frequently used in the treatment of invasive infections. Factors associated with the resistance to aminoglycosides include the reduction of drug uptake, modification of aminoglycosides, and aminoglycoside efflux. Objectives: The aim of our study was to phenotypically detect the presence of efflux mechanism using carbonyl cyanide 3chlorophenylhydrazone (CCCP) in aminoglycoside resistant Acinetobacter baumannii strains isolated from different hospital wards. Methods: In total, 57 A. baumannii isolates were collected from two Egyptian hospitals. The antimicrobial susceptibility pattern was determined. The activity of the efflux system was evaluated using CCCP. Results: Among 57 A. baumannii isolates, most resistance was observed against tobramycin, amikacin, kanamycin, neomycin, and gentamicin. The minimum inhibitory concentrations (MIC) range of A. baumannii was between 2 and 1024 µg/mL based on the tested antibiotics. The phenotypic detection of efflux pumps displaying a reduction of at least two folds in the MICs of antibiotics after addition of the efflux pump inhibitor showed that 19.4% of the isolates became less resistant to kanamycin, 44% to tobramycin, and 46% to amikacin but lower rates were recorded against gentamicin (12.2%) and neomycin (9.4 %). Conclusions: Our study suggests that the efflux mechanism is getting widespread in clinical settings to play an important role in aminoglycoside resistance. Acinetobacter baumannii has the ability to gain resistance to different antibiotic classes through these active efflux pumps. Hence, the application of strict infection control measures together with novel approaches to eradicate those efflux transporters should be applied in hospital settings.