| In this study 150 samples of Respiratory tract infection (RTIs) were collected from patients suffering from upper and lower Respiratory tract infection (RTIs). From all these sample Pseudomonas aeruginosa was represented the most bacteria isolates 70 (46.6%) . All these isolates were diagnosed by convenatial and molecular methods. Molecular study showed all P.aeruginosa isolates gave positive results (230 bp) for 16s rRNA assay. Most isolates of P. aeruginosa were appeared a highest rate of resistance(100%) to Cefriaxine , Cefotoxime , Doxicycline, Nalidixic acid, Nitrofurantion, Cefixime, while it was (68.5%) to Gentamycine and 65.7% for each of Amikacin, Ceftrazidime, Trimethoprim and Cefepime. Moderately resistance to Tobromycin and Piperacillin and relatively lower resistance to Azitronam , Imipenem, Azthromycin and Ciprofloxacin was also observed. Multiple drug resistance (MDR) was appear many patterns, these include 7 patterns that were repeated more than three times, in which the pattern (NA, AK, CAZ, CRO ,F, TOB, FEP, DO, CN, CFM) was appeared the high rate of repeated than other patterns. |