title: Multidrug resistant Gram-negative bacilli in lower respiratory tract infections.
abstract: BACKGROUND
  Lower respiratory tract infections are among important causes of morbidity and mortality for all age groups. The emergence of multidrug resistant Gram-negative bacilli is an issue of increasing concern.
  
  
  METHODS
  A retrospective study including respiratory specimens (sputum and BAL) was conducted in our tertiary care centre. Samples were processed for microscopy, culture and susceptibility testing following standard methods. Multidrug resistant Gram-negative bacilli causing lower respiratory tract infections were studied for their causation of disease. The effect of appropriate treatment on clinical outcome was observed.
  
  
  RESULTS
  A total of 472 Gram-negative pathogens were isolated from sputum and broncho-alveolar lavage fluid specimens during the study period. Among these Gram-negative pathogens 175 (37%) were found to be multidrug resistant. Klebsiella pneumoniae 85 (48.6%) and Acinetobacter spp. 59 (33.7%) were the predominant multidrug resistant Gram-negative bacilli isolated. Based on clinico-microbiological correlation, 138 (78.9%) multidrug resistant isolates were found to be pathogenic and the rest 37 (21.1%) were considered as colonizers. After initiating appropriate antibiotic therapy, clinical improvement was seen in 110 (79.7%) patients. In the patients who showed improvement, amikacin (34.3%) and cefoperazone-sulbactum (21.8%) were found to be the most effective drugs.
  
  
  CONCLUSIONS
  A large majority of the isolated multidrug resistant Gram-negative bacilli were found to be pathogenic. Regular surveillance which directs appropriate empirical therapy; and good clinic-microbiological workup of each case of lower respiratory tract infection can reduce the morbidity and mortality associated with multidrug resistant organisms.
authors.affiliation: Department of Microbiology, Kasturba Medical College, Manipal University, Manipal. India.
authors.forename: Shashidhar
authors.initials: S
authors.lastname: Vishwanath
authors.affiliation: Department of Microbiology, Kasturba Medical College, Manipal University, Manipal. India.
authors.forename: Kiran
authors.initials: K
authors.lastname: Chawla
authors.affiliation: Department of Microbiology, Kasturba Medical College, Manipal University, Manipal. India.
authors.forename: Anusha
authors.initials: A
authors.lastname: Gopinathan
keywords: Acinetobacter spp.; Gram-negative bacilli; Klebsiella pneumoniae; Lower respiratory infection; Multidrug resistance
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