Bacteria of Apis mellifera Gastrointestinal Tract: Counts, Identification and Their Antibiotic Resistance

Abstract

The aim of the present study was to identify of bacterial species inhabiting the intestinal tract of Apis mellifera L. Content on intestinal tract was cultured for isolation of Gram-negative and Gram-positive bacteria. Content of gut was streaked onto MacConkey agar which was incubated for 24–48 h at 37 °C aerobically. For cultivation of Gram-positive and Gram-negative microflora, the inoculated Tryptone soya agar was incubated for 48–72 h at 30 °C. Then, the identification of isolates with MALDI-TOF MS Biotyper was done. After bacteria identification antibiotic resistance testing was done. Disc diffusion methods was applied and the following antibiotics discs were used: amikacin AMK (10 μg), gentamicin GEN (10 μg), tigecycline TGC (10 μg) and chloramphenicol CM (10 μg). Results show that the Gram-positive bacteria counts were from 2.17 ±0.04 to 3.21 ±0.02 log CFU/g and Gram-negative counts ranged from 2.36 ±0.14 to 4.05 ±0.04 log CFU/g in honey bee gut samples. Lactococcaceae, Micrococcaceae, Staphylococcaceae and Enterobacteriaceae were identified from Gram-positive and Gram-negative bacteria in bees gut. The Enterobacteriaceae were the most abundant and were represented with 8 bacterial species. The Gram-positive and Gram-negative bacterial species recovered exhibited the antimicrobial resistance to the antibiotics. Gram-positive and Gram-negative bacterial showed the more frequently resistance to tigecycline (9.5%) and amikacin (8.2%). The resistance to gentamycin (6.5%) and chloramphenicol (4.1%) was observed less frequently.