Increasing secondary bacterial infections with Enterobacteriaceae harboring blaCTX–M–15 and blaCMY-6 in patients with bronchogenic carcinoma: an emerging point of concern

ObjectiveTo look for secondary bacterial infections in bronchogenic carcinoma (BCA) with resistant organisms harboring bla genes considering the paucity of relevant studies.MethodsA total of 137 confirmed cases of BCA and 34 healthy volunteers were studied for the occurrence and prevalence of blaCTX-M and and blaAmpC harboring–enterobacteriaceae. A subset of these patients (n=69) was previously reported for the secondary infection with the Aspergillus species. Bronchoalveolar lavages (BAL) were subjected for bacterial and fungal cultures and the bacterial isolates were screened by multiplex PCRs for the presence of blaCTX–M and blaAmpC. The isolates were also screened for the association of insertion sequence (IS26) by PCR and characterized by RAPD for any clonal relatedness.ResultsA total of 143 bacterial isolates were obtained from 137 BAL specimens of BCA patients. The Enterobacteriaceae–isolates were multidrug-resistant showing concomitant resistance to fluoroquinolones and aminoglycosides. Both blaCTX-M and blaAmpC of CIT family were detected in 77.4% and 27.4% isolates, respectively. Sequencing revealed the presence of blaCTX–M–15 and blaCMY-6. Twenty one percent of the isolates were simultaneously harboring blaampC and blaCTX–M–15. IS26 PCR and RAPD typing revealed the presence of diverse bacterial population but no predominant clone was identified. The present study also suggests strong association of aspergillosis with lung cancer and further strengthens the potential use of non-validated serological tests suggested earlier.ConclusionsWe emphasize that all patients of bronchogenic carcinoma should also be screened for secondary bacterial infections, along with secondary fungal infections, so as to introduce early and specific antimicrobial therapy and to prevent unwanted deaths.