To isolate, characterize and assess the anti-multiple-drug resistant (MDR) bacterial potential
of culturable endophytes from A. corniculatum
in Beibu Gulf, China.
The plant parts were collected from healthy-looking A. corniculatum.
The endophytes were
isolated and identified by colonial morphology and macroscopic characteristics and DNA sequencing of
fungal ITS region, and then grouped by phylogenetic analysis. Antibacterial activity was assayed using
five human pathogenic bacteria ( B. cereus
, P. aeruginosa
, E. coli
, K. pneumoniae
and A. baumanii
of which two of them were MDR bacteria. Ethyl acetate extracts from endophytes were prepared, and
the minimum inhibitory concentration (MIC) of 3 endophytes was tested using serial 2-fold dilutions of
61 endophytes obtained from A. corniculatum
were grouped into 6 genera (Colletotrichum
were the most frequent genera, accounting for colonization frequencies (CF) of 29.5 and 37.7%. Among
the rare morphotypes, Alternaria
were the infrequent
genera, accounting for CF ranging from 3.2 to 13.1%. Overall, 3 endophytes, including Glomerella
, and Cladosporium
, all isolated from the leaves, showed inhibitory activity against five test
bacteria in vitro. The endophyte, Colletotrichum
, inhibited two MDR K. pneumoniae
and A. baumanii
inhibits MDR K. pneumoniae
. The MIC of the extract of Colletotrichum
against MDR K.
was 4 μg/ml, against MDR A. baumanii
was 0.5 μg/ml, while MIC of Guignardia
was 8 μg/ml.
The study demonstrates that endophytes from mangrove plant A. corniculatum
fascinating fungal reservoir against MDR pathogenic bacteria.