CHARACTERIZATION, ANTIMICROBIAL PROFILE, AND BIOFILM FORMATION OF ACINETOBACTER SPECIES ISOLATED FROM MILK AND HUMAN

One hundred milk samples were obtained from diverse places in Qena City, and fifty urine samples were gathered from patients with Urinary Tract Infections (UTIs) attending various laboratories in Qena City. All the samples were examined for the presence of Acinetobacter species on Leeds Acinetobacter Medium (LAM). The suspected colonies were identified through Gram staining and biochemical tests. The recA gene was identified using polymerase chain reaction (PCR), which was used for the molecular identification of the Acinetobacter species, and the identified species were further characterized by sequencing this gene. Phylogenetic analysis of the Acinetobacter species was then conducted. The identified Acinetobacter species were tested for antibiotic susceptibility and their ability to produce biofilm. The results of this study showed that 20 out of 150 samples were positive for Acinetobacter species using conventional isolation methods. Using PCR techniques, 18 samples were positive for Acinetobacter. Sequencing of the recA gene for the 18 isolates revealed 7 Acinetobacter species, which were identified as 3 A. baumannii, 1 A. nasocomialis, 1 A. urisingii, and 2 A. johnsonii. The antibiotic susceptibility testing showed that most Acinetobacter species were multi-antibiotic resistant (MAR) and harbored antibiotic resistance genes. The results of biofilm formation testing, using both the Congo red and microtiter plate methods, revealed that most Acinetobacter isolates were strong biofilm producers. In conclusion, the presence of Acinetobacter species which are highly resistant to antibiotics especially A. baumannii in milk and urine samples may threaten public health.