Antibiotic supplement in feed can perturb the intestinal microbial composition and function in Pacific white shrimp

The intestinal microbiota plays crucial roles in host health. The Pacific white shrimp is one of the most profitable aquaculture species in the world. Antibiotic supplement in feed is an optional practice to treat shrimp bacterial diseases. However, little is known about antibiotic effects on intestinal microbiota in pacific white shrimp. Here, shrimps were given feed supplemented with ciprofloxacin (Cip) (40 and 80 mg kg−1) and sulfonamide (Sul) (200 and 400 mg kg−1) to investigate the microbial community by targeting the V4 region of 16S rRNA genes. Within 4 days after feeding with normal feed and with antibiotics, antibiotic concentrations of Cip and Sul groups in the intestine dropped sharply. Significantly, increased abundance of antibiotic resistance genes (ARGs) of ciprofloxacin (qnrB, qnrD, and qnrS) and sulfonamide (sul1, sul2, and sul3) was observed in Cip and Sul groups (P