AUTHOR=Meng Lu , Liu Huimin , Lan Tu , Dong Lei , Hu Haiyan , Zhao Shengguo , Zhang Yangdong , Zheng Nan , Wang Jiaqi 

TITLE=Antibiotic Resistance Patterns of Pseudomonas spp. Isolated From Raw Milk Revealed by Whole Genome Sequencing

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01005

DOI=10.3389/fmicb.2020.01005

ISSN=1664-302X

ABSTRACT=<p>Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and the economic losses they cause to the dairy industry. Food-related psychrotrophic bacteria are increasingly reported to have antibiotic resistance features. The aim of this study was to evaluate the resistance patterns of <italic>Pseudomonas</italic> spp. isolated from bulk-tank milk. In total, we investigated the antibiotic susceptibility profiles of 86 <italic>Pseudomonas</italic> spp. isolates from raw milk. All strains were tested against 15 antimicrobial agents. <italic>Pseudomonas</italic> isolates were most highly resistant to imipenem (95.3%), followed by trimethoprim-sulfamethoxazole (69.8%), aztreonam (60.5%), chloramphenicol (45.3%), and meropenem (27.9%). Their multiple antibiotic resistance (MAR) index values ranged from 0.0 to 0.8. Whole-genome sequencing revealed the presence of intrinsic resistance determinants, such as BcI, <italic>amp</italic>C-09, <italic>bla</italic>CTX-M, <italic>opr</italic>D, <italic>sul</italic>1, <italic>dfr</italic>E, <italic>cat</italic>A1, <italic>cat</italic>B3, <italic>cat</italic>I, <italic>flo</italic>R, and <italic>cml</italic>V. Moreover, resistance-nodulation-cell division (RND) and ATP-binding cassette (ABC) antibiotic efflux pumps were also found. This study provides further knowledge of the antibiotic resistance patterns of <italic>Pseudomonas</italic> spp. in milk, which may advance our understanding of resistance in <italic>Pseudomonas</italic> and suggests that antibiotic resistance of <italic>Pseudomonas</italic> spp. in raw milk should be a concern.</p>