en میکروب شناسی Microbiology مقالات اصلی Original Article <div style="text-align: justify;"><em><strong>Background: </strong></em>Multidrug resistance Pseudomonas aeruginosa (MDRPA) is most important issue in&nbsp;healthcare setting. It can secrete many virulence effector proteins via its secretion system type (T1SS-T6SS).&nbsp;They are using them as conductor for delivering the effector proteins outside to begins harmful effect on&nbsp;host cell increasing pathogenicity, competition against other microorganism and nutrient acquisition.&nbsp;<br> <br> <strong>Methods:</strong> The study include investigation of 50 isolates of MDRPA for transport secretion system and&nbsp;resistance for antibiotics. Molecular diagnosis using P. aeruginosa specific primer pairs, investigation of&nbsp;AprF, HasF, XcpQ, HxcQ, PscC, CdrB, CupB3, and Hcp using specific primer pairs by PCR were also<br> performed.<br> <br> <em><strong>Results:</strong></em> The results revealed high resistance to beta lactam antibiotics (78% for ceftazidime, 78% for&nbsp;cefepime and 46% for piperacillin) can indicate possessing of isolates for beta lactamases and this confirmed&nbsp;by dropping resistance to piperacillin to 16% when combined with tazobactam. Also, the results shown the&nbsp;ability of MDRPA for pyocyanin biosynthesis using the system of genes.<br> <br> <strong><em>Conclusions: </em></strong>The current study conclude that all isolates of P. aeruginosa were highly virulent due to their&nbsp;possessing of all transport secretion system to deliver different effector proteins with possible harmful effects&nbsp;of these proteins.</div> Drug resistance, MDR, Efflux pump, Pseudomonas aeruginosa. 102 110 http://rbmb.net/browse.php?a_code=A-10-779-1&slc_lang=en&sid=1 Maytham Hassan Jasim Al-Thabhawee 100319475328460012354 100319475328460012354 Yes Biology Department, College of Science, University of Babylon, Iraq. Hussein Oleiwi Muttaleb Al-Dahmoshi 100319475328460012355 100319475328460012355 No Biology Department, College of Science, University of Babylon, Iraq.