ABSTRACT
Introduction: Respiratory tract infections are a majorcause of ambulatory visits to the family practitioners.However, increase in antibiotic resistant strains of bacteriahas complicated the use of empiric therapy of this commonhuman disease. Among the Gram negative bacilli which arethe commonest pathogen of LRTI, Pseudomonas aeruginosais the most challenging, because of its high rate of resistanceto antimicrobial agent. Objectives: To obtain a comprehensiveinsight into the different resistant types: Multi drug resistant,Extensively drug resistant, Carbapenem Resistant, and MBLproducing Pseudomonas aeruginosa isolated from lowerrespiratory tract specimens and antibiotic susceptibilitydifferences between its mucoid and non mucoid colony typesbased on colony morphology.Material and Methods: A total of 926 lower respiratorytract samples consisting of sputum,pleural fluid,endotrachealaspirates,Bronchoalveolar lavage from patients of all ageand sex , suggestive of LRTI were included . FollowingDirect Gram staining and culture, the organisms wereisolated and Pseudomonas aeruginosa among them wereidentified by standard biochemical tests. The different typesof colony morphologies of Pseudomonas aeruginosa and theantimicrobial susceptibility differences amongst the differentcolony types were statistically analysed.Results: A total 175 (18.8%) Pseudomonas were isolatedfrom different Lower respiratory specimen Out of these, only103 Pseudomonas aeruginosa were found to be clinicallysignificant with 84.5% non mucoid and 11.4% mucoid colonytypes. The mucoid colony types showed high resistanceto Cefepime (35%), followed by Ceftazidime (20%) andAmikacin (15%).Conclusion: The high rate of MDR and XDR Pseudomonasaeruginosa also resistant to Carbapenems from this regionreveals a frightening scenario.As molecular methods are notavailable in majority of resource constrained laboratories ofIndia, the phenotypic methods should be regularly performedto detect the various beta-lactamases, besides strict infectioncontrol practices.