Abstract: Strain HY-1, isolated from raw milk, was identified as Hafnia alvei by morphological, physiological and biochemical characterization and 16S rRNA sequence analysis, and its biological properties such as resistance to antibiotic, salt, acid and alkali, swimming motility and biofilm formation capacity were evaluated. Results showed that HY-1 was resistant to a wide range of antibiotics, which was moderately susceptible to tetracycline, erythromycin, penicillin G, ceftazidime, and cefuroxime axetil, and was resistant to midecamycin, clindamycin, clarithromycin, oxacillin, cephalothin, and cefazolin. HY-1 could grow in media at pH 5.0–8.0 containing 0.2–0.5 g/mL of sodium chloride at 4–37 ℃, and showed swimming motility as evidenced by the halo on the surface of the swimming plate. In addition, HY-1 could form biofilms, and milk at 2 mg/mL had the potential to facilitate biofilm formation by HY-1 and consequently increase its transmission and contamination, which may cause food quality and safety problems. However, when the concentration of NaCl equaled or exceeded 0.4 g/mL, the biofilm formation ability of HY-1 was significantly inhibited, indicating that the transmission and contamination of HY-1 could be intercepted by appropriate concentrations of NaCl.

Key words: raw milk; Hafnia alvei; isolation and identification; biological characteristics

摘要： 为探究蜂房哈夫尼菌的生物学特性，通过细菌分离纯化、形态特征、生理生化鉴定和16S rRNA序列分析等从生牛乳中分离鉴定出1 株蜂房哈夫尼菌HY-1，并测定其耐药性、耐盐性、耐酸碱、泳动性及生物被膜形成等生物学特性。结果表明：牛乳源蜂房哈夫尼菌HY-1具有广泛的耐药性，对四环素、红霉素、青霉素G、头孢他啶、头孢呋辛酯中度敏感，对麦迪霉素、克林霉素、克拉霉素、苯唑西林、头孢噻吩、头孢唑林耐药；该菌的生存范围比较广，能够在4～37 ℃条件下以及0.2～0.5 g/mL NaCl和pH 5.0～8.0的培养基上正常生长，并且可以在泳动培养基表面扩散，表明其具有泳动性；此外，蜂房哈夫尼菌HY-1能够形成较强的生物被膜，而2 mg/mL牛乳具有促进蜂房哈夫尼菌HY-1生物被膜形成的潜在能力，进而增强菌株的传播和污染，引发食品质量和安全问题；但是，当NaCl质量浓度在0.4 g/mL及以上时，显著抑制蜂房哈夫尼菌HY-1生物被膜形成能力，表明可以通过适当提高NaCl质量浓度阻断蜂房哈夫尼菌HY-1的传播和污染。

关键词: 生牛乳；蜂房哈夫尼菌；分离鉴定；生物学特性