Open AccessCharacterization of Antibacterial Activities of Eastern Subterranean Termite, Reticulitermes flavipes, against Human Pathogens
Author(s) -
Yuan Zeng,
Xing Ping Hu,
Sang-Jin Suh
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0162249
Subject(s) - microbiology and biotechnology , antimicrobial , bacteria , acinetobacter baumannii , biology , pseudomonas aeruginosa , antibacterial activity , staphylococcus aureus , hemolymph , multiple drug resistance , reticulitermes , antibiotics , antibiotic resistance , ecology , rhinotermitidae , genetics
The emergence and dissemination of multidrug resistant bacterial pathogens necessitate research to find new antimicrobials against these organisms. We investigated antimicrobial production by eastern subterranean termites, Reticulitermes flavipes , against a panel of bacteria including three multidrug resistant (MDR) and four non-MDR human pathogens. We determined that the crude extract of naïve termites had a broad-spectrum activity against the non-MDR bacteria but it was ineffective against the three MDR pathogens Pseudomonas aeruginosa , methicillin-resistant Staphylococcus aureus (MRSA), and Acinetobacter baumannii . Heat or trypsin treatment resulted in a complete loss of activity suggesting that antibacterial activity was proteinaceous in nature. The antimicrobial activity changed dramatically when the termites were fed with either heat-killed P . aeruginosa or MRSA. Heat-killed P . aeruginosa induced activity against P . aeruginosa and MRSA while maintaining or slightly increasing activity against non-MDR bacteria. Heat-killed MRSA induced activity specifically against MRSA, altered the activity against two other Gram-positive bacteria, and inhibited activity against three Gram-negative bacteria. Neither the naïve termites nor the termites challenged with heat-killed pathogens produced antibacterial activity against A . baumannii . Further investigation demonstrated that hemolymph, not the hindgut, was the primary source of antibiotic activity. This suggests that the termite produces these antibacterial activities and not the hindgut microbiota. Two-dimensional gel electrophoretic analyses of 493 hemolymph protein spots indicated that a total of 38 and 65 proteins were differentially expressed at least 2.5-fold upon being fed with P . aeruginosa and MRSA, respectively. Our results provide the first evidence of constitutive and inducible activities produced by R . flavipes against human bacterial pathogens.