Molecular diversity and Biofilm Formation in Extensively Drug Resistant Acinetobacter baumannii Isolated from Patients in Diyala.

Acinetobacter baumannii is a worldwide threat that causes infections in hospital settings because of multidrug resistance to widely available antimicrobial drugs. The study aimed to determine antimicrobial susceptibility and biofilm formation in A. baumannii clinical isolates and the molecular diversity of these isolates by using the 16S rRNA gene. The bacterial isolates have been recovered from patients admitted to Baquba Teaching Hospital in Diyala, Iraq. Diagnoses were then confirmed using biochemical tests, VITEK-2 system and molecular screening of 16S rRNA Genes were done by PCR. 30 distinct isolates were identified as A. baumannii throughout the collection. All A. baumannii isolates were resistance to piperacillin, Ceftazidime, Cefotaxime, Ceftriaxone, piperacillin-tazobactam, ticarcillin-clavulanic acid, gentamicin (100%). While resistance to Amikacin was 96.7%, Imipenem and Meropenem 76.7%, Levofloxacin 66.7%, and finally to Ciprofloxacin 63.3%, 11 isolates (36.7%) were MDR, and 19 (63.3%) isolates were XDR. The results of this study also observed there were 19 moderate biofilm-producing strains and 8 isolates that were weak, while only 3 isolates had strong biofilm. The results showed 13 A. baumannii isolates 43.3% were given positive results for metallo-beta-lactamase versus 17 isolates 56.7% given negative results. A total of eight samples (assigned S1 - S8) were included in the present study. The conducted sequencing reactions of 16S rRNA amplicons indicated the accurate identity of the investigated samples, which were found to be attributed to Acinetobacter baumannii. The alignment of nucleic acid sequences of the eight isolates revealed the presence of four nucleic acid variants distributed in S1–S8 samples. Unique accession numbers were obtained for all analyzed sequences and each sequence took accession number., 16S rRNA sequencing is an effective approach for identifying and characterizing clinical samples of Acinetobacter baumannii, with various clinical benefits such as high sensitivity and specificity, cheap cost, and quick turnaround time.