Effective therapeutic strategies against Pseudomonas aeruginosa and Burkholderia Cepacia complex infections

Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) can cause serious nosocomial infections. The reported misidentification of Bcc as P. aeruginosa, besides the contrasting susceptibility patterns between these two pathogens, underscores the importance of accurate identification and the need to explore therapeutic approaches that could eradicate them both. Our study aimed to evaluate the susceptibilities of both pathogens to different antibiotics and test the effectiveness of different antimicrobial combinations. In addition, we compared conventional phenotypic and automated identification methods using the VITEK 2 system with PCR amplification and sequencing of recA gene to differentiate between P. aeruginosa and Bcc. Amplification by PCR of the recA gene showed high specificity in the identification of Bcc in comparison with conventional and automated phenotypic methods. Significant differences in susceptibility were observed with P. aeruginosa isolates having more susceptibility to colistin and ceftazidime, while Burkholderia isolates were more susceptible to cotrimoxazole and minocycline. Both P. aeruginosa and Burkholderia isolates tested were more susceptible to N-Acetyl-L-Cysteine (NALC) plus meropenem or levofloxacin, followed by gentamicin plus piperacillin/tazobactam. Synergistic effect of NALC plus meropenem or levofloxacin may help in the eradication of both pathogens to overcome the diagnostic challenges posed by the possible misidentification using conventional identification methods.