multiple infections

My mother is 76 with COPD (emphysema) she has been consistently sick since Feb 2006. Last September she was diagnosed having  Stenotrophomonas maltophilia. She was given Septra and multiple other antibiotics. Last month the gave her a PICC line and timentin. Her labs went from moderate growth to heavy and her normal flora is low.

Last week they did a brochioscopy and as the result they have found Acinetobacter baumannii in both lungs. The Acinetobacter baumannii is in the lower portion and the Stenotrophomonas maltophilia in the upper. They want to treat her again with Septra because the cultures they grew died when it was administered. If the Septra doesn't work there are only 2 other drugs that respond to the A. baumannii, both are neuro and nephro toxic.

My question is what are the chances that since they have given her Septra multiple times in the past treating the S. maltophilia, that the A. baumannii will mutate and render the Septra useless?

[National Jewish Health]

Acinetobacter is a formidable pathogen that has the ability to rapidly develop resistance to all currently available antimicrobial agents, especially when it infects hospitalized people with other health problems and/or severe illness of any type.  So, the answer to your question regarding treatment of Acinetobacter with Septra® DS (sulfamethoxazole and trimethoprim) and the development of resistance to the medicine is yes.

Medicines with some effectiveness against this pathogen include imipenem or a third-generation cephalosporin, with or without amikacin.  For imipenem-resistant strains, ampicillin-sulbactam and piperacillin-tazobactam is another alternative.  These medicines are not without toxicity.  And, Timentin® (ticarcillin and clavulanate potassium) may also be effective against this pathogen.  Ultimately, the risk of toxicity may have to be accepted, if there are no other safer medicines to choose from.

This is a complex situation in which you will have to rely upon the judgment of an experienced infectious disease specialist, familiar with the patterns of bacterial sensitivity and resistance in your community.

Good luck.

[ICURNJIM]

A related discussion, Stentotrophamonas in non-immunocompromised 45yo male was started.