Netilmicin Sulfate

The resistance genes encoding aminoglycoside-modifying enzymes (AMEs) are now widely prevalent in different populations of Staphylococcus aureus. The study aimed to determine the frequency of AMEs-encoding genes in clinical isolates of S. aureus.

A total of 105 S. aureus isolates were obtained from the different clinical samples; and then were identified by conventional biochemical tests. The antibiotic resistance patterns of the isolates were characterized by the agar disk diffusion method. The distribution of the AMEs and femA genes was determined by conventional and multiplex PCR.

The aminoglycoside resistance rates of kanamycin, tobramycin, gentamicin, amikacin, and netilmicin were 47.6%, 46.6%, 45.7%, 45.7%, and 26.6%, respectively. 16.1% and 1.9% of isolates were MDR and XDR phenotypes, respectively. 21.9% of S. aureus isolates harbored the femA gene and were determined as methicillin-resistant S. aureus (MRSA) clones. The aac(6')/aph(2'') was the most prevalent (47.8%) AME-encoding gene in aminoglycoside-resistant S. aureus, followed by ant(4')-Ia (30.4%) and aph(3')-IIIa (21.7%).

Our study demonstrated that the coexistence of several AMEs and the spread of the resistance determinants like femA in S. aureus clinical isolates are alarming and may contribute to the broadening of aminoglycoside resistance spectra and limit treatment options for staphylococcal infections.

The emergence of antibiotic resistance has significantly elevated the threat posed by Acinetobacter baumannii as an opportunistic pathogen. A.baumannii, a notorious bacterium, poses a serious threat to health care, leading to severe nosocomial infections, particularly in immunocompromised individuals. Whole-Genome Sequencing studies are efficient in providing accurate genetic information, aiding in detecting outbreaks, surveillance of resistance, and controlling infection transmission. In this study, we investigated the whole genome of a clinical isolate A. baumannii JJAB01 which sourced from a urine sample of an Intensive Care Unit (ICU) patient. This strain showed resistance to 24 available antibiotics, signifying Extremely Drug Resistant (XDR) and high potential for pathogenicity. Whole Genome Sequencing was performed using Illumina, and the raw reads were evaluated using the FastQC tool. Genome assembly and annotation were performed with Unicycler and the RAST server. The JJAB01 genome is 4.07 Mb with a GC content of 38.9 %. A total of 51 and 31 virulence factors and antimicrobial-resistant (AMR) genes were predicted using the VFDB and CARD databases. Comparative genome studies were carried out on virulence factors, resistance genes, prophages, and Multi-Locus Sequence Typing (MLST) across twelve closely related A. baumannii genomes, including JJAB01, X4-584, X4-705, 2023CK-00423, 2023CK-00890, 2023CK-00127, 2022CK-00066, B20AB01, B20AB10, F20AB03, G20AB08, and X4-65. These computational investigations in this study emphasis the multidimensional nature of the ICU strain JJAB01 and its genetic similarity to other strains, thereby enhancing our understanding of drug resistance and the pathogenicity associated with A. baumannii infections.