Antisense phosphorodiamidate morpholino oligomers targeted to an essential gene inhibit Burkholderia cepacia complex.
BACKGROUND
Members of the Burkholderia cepacia complex (Bcc) cause considerable morbidity and mortality in patients with chronic granulomatous disease and cystic fibrosis. Many Bcc strains are antibiotic resistant, which requires the exploration of novel antimicrobial approaches, including antisense technologies such as phosphorodiamidate morpholino oligomers (PMOs).


METHODS
Peptide-conjugated PMOs (PPMOs) were developed to target acpP, which encodes an acyl carrier protein (AcpP) that is thought to be essential for growth. Their antimicrobial activities were tested against different strains of Bcc in vitro and in infection models.


RESULTS
PPMOs targeting acpP were bactericidal against clinical isolates of Bcc (>4 log reduction), whereas a PPMO with a scrambled base sequence (scrambled PPMO) had no effect on growth. Human neutrophils were infected with Burkholderia multivorans and treated with AcpP PPMO. AcpP PPMO augmented killing, compared with neutrophils alone and compared with neutrophils alone plus scrambled PPMO. Mice with chronic granulomatous disease that were infected with B. multivorans were treated with AcpP PPMO, scrambled PPMO, or water at 0, 3, and 6 h after infection. Compared with water-treated control mice, the AcpP PPMO-treated mice showed an approximately 80% reduction in the risk of dying by day 30 of the experiment and relatively little pathology.


CONCLUSIONS
AcpP PPMO is active against Bcc infections in vitro and in vivo.
Greenberg
David E
DE
Immunopathogenesis Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, Office of Research Services, National Institutes of Health, Bethesda, Maryland, USA. degreenberg@niaid.nih.gov
Marshall-Batty
Kimberly R
KR
Brinster
Lauren R
LR
Zarember
Kol A
KA
Shaw
Pamela A
PA
Mellbye
Brett L
BL
Iversen
Patrick L
PL
Holland
Steven M
SM
Geller
Bruce L
BL
D000213:Acyl Carrier Protein / Q000037:antagonists & inhibitors; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors; D019121:Burkholderia Infections / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D042602:Burkholderia cepacia complex / Q000187:drug effects*; D002470:Cell Survival; D004195:Disease Models, Animal; D006105:Granulomatous Disease, Chronic / Q000150:complications; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D009025:Morpholines / Q000494:pharmacology / Q000627:therapeutic use*; D060172:Morpholinos; D009504:Neutrophils / Q000382:microbiology; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology / Q000627:therapeutic use*; D016019:Survival Analysis
D000213:Acyl Carrier Protein; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D009025:Morpholines; D060172:Morpholinos; D020319:Oligodeoxyribonucleotides, Antisense