实验动物与比较医学 ›› 2026, Vol. 46 ›› Issue (3): 367-377.DOI: 10.12300/j.issn.1674-5817.2025.150

• 实验动物质量控制 • 上一篇    下一篇

食蟹猴源弗氏柠檬酸杆菌的分离鉴定及生物学特性分析

李鹤龄1, 钱子瑶1, 覃刚民2, 蒋德兵2, 张艳琼2, 金文政2, 王宏1,2()()   

  1. 1.昆明理工大学灵长类转化医学研究院, 昆明 650500
    2.云南中科灵长类生物医学重点实验室, 昆明 650500
  • 收稿日期:2025-09-16 修回日期:2025-12-02 出版日期:2026-06-25 发布日期:2026-06-19
  • 通讯作者:
    王 宏(1975—),男,博士,研究员,研究方向:实验动物疾病的诊断与治疗。E-mail:wangh@lpbr.cn。ORCID:0009-0004-6763-3168
  • 作者简介:李鹤龄(1990—),女,硕士,高级兽医师,研究方向:非人灵长类动物疾病的诊断与治疗。E-mail:lihl@lpbr.cn
  • 基金资助:
    云南省自然科学基金项目“灵长类生殖发育与人类重大疾病的机制及转化研究”(202001BC070001)

Isolation, Identification and Biological Characteristics Analysis of Citrobacter freundii from Cynomolgus Monkey (Macaca fascicularis)

LI Heling1, QIAN Ziyao1, QIN Gangmin2, JIANG Debing2, ZHANG Yanqiong2, JIN Wenzheng2, WANG Hong1,2()()   

  1. 1.Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming 650500, China
    2.Yunnan Key Laboratory of Primate Biomedical Research, Kunming 650500, China
  • Received:2025-09-16 Revised:2025-12-02 Published:2026-06-25 Online:2026-06-19
  • Contact: WANG Hong (ORCID: 0009-0004-6763-3168), E-mail: wangh@lpbr.cn

摘要:

目的 对1株导致食蟹猴腹泻的致病菌进行鉴定分析、动物回归试验和药物敏感性研究,为弗氏柠檬酸杆菌的临床治疗提供实践依据。 方法 收集9只腹泻食蟹猴的新鲜粪便,分别划线接种于沙门-志贺氏(Salmonella-Shigella,SS)培养基、LB培养基和哥伦比亚血琼脂培养基,37 ℃恒温培养24 h。随后通过菌落形态观察、革兰氏染色、生化试验和16S rRNA基因测序对分离菌株进行鉴定,并采用PCR方法检测分离菌株的主要毒力基因;将分离菌增殖后灌胃健康食蟹猴和C57BL/6小鼠进行动物回归试验,以分析菌株的致病性;最后,采用圆片扩散法检测分离菌株的药物敏感性。 结果 从9只腹泻食蟹猴的粪便样本中共分离到1株细菌,命名为MF071743。该分离菌株在SS培养基上形成粉红色、光滑的圆形菌落;在LB培养基上形成光滑、湿润、表面有光泽、边缘整齐的半透明菌落;在哥伦比亚血琼脂上形成光滑湿润的灰白色菌落。革兰氏染色结果显示,该菌株为革兰氏阴性、无芽孢短杆菌。生化实验结果显示,该分离菌株动力试验为阳性,甘露醇试验、硫化氢试验、甲基红试验、枸橼酸盐利用试验、葡萄糖产气试验、棉子糖试验、山梨醇试验和D-木糖发酵试验均为阳性,但苯丙氨酸试验、葡萄糖酸盐试验、吲哚试验、伏-波(Voges Proskauer,VP)试验、脲酶试验、赖氨酸试验、鸟氨酸试验和侧金盏花醇试验均为阴性。16S rRNA基因测序结果显示,MF071743与弗氏柠檬酸杆菌基因组的相似度高达99.0%。PCR结果显示,该菌株携带编码脲酶辅助蛋白(urease accessory protein,ure)D、ureE和ureF的基因。动物灌胃实验结果显示,该菌株能导致食蟹猴粪便稀软,C57BL/6小鼠72 h内全部死亡(100%)。药敏试验结果显示,该菌株对头孢曲松、阿米卡星、庆大霉素、头孢他啶、左氧氟沙星等16种药物敏感,对氨苄西林、头孢唑林、万古霉素、红霉素和头孢氨苄耐药。 结论 从食蟹猴腹泻粪便中分离到1株弗氏柠檬酸杆菌,该菌株对多种抗生素具有耐药性,本研究结果为圈养实验猴消化道疾病的诊断和治疗提供了参考。

关键词: 食蟹猴, 弗氏柠檬酸杆菌, 细菌培养, 分离鉴定, 系统发育分析

Abstract:

Objective Identification and analysis, animal regression test, and drug susceptibility study were conducted on a pathogenic strain causing diarrhea in cynomolgus monkeys, aiming to provide a practical basis for the clinical treatment of Citrobacter freundii. Methods Fresh fecal samples were collected from nine diarrheal cynomolgus monkeys and streaked on Salmonella-Shigella (SS) medium, LB medium, and Columbia blood agar medium, and incubated at 37 ℃ for 24 h. Subsequently, the isolated strain was identified by colony morphology observation, Gram staining, biochemical tests and 16S rRNA gene sequencing, and PCR was used to detect its major virulence genes. After propagation, the isolate was intragastrically administered to healthy cynomolgus monkeys and C57BL/6 mice for animal regression tests to evaluate its pathogenicity. Finally, the disk-diffusion method was used to detect the antimicrobial susceptibility of the isolate. Results A single bacterial strain, designated MF071743, was isolated from 9 fecal samples collected from diarrheal cynomolgus monkeys. The isolate formed pink, smooth, round colonies on SS medium; translucent, smooth, moist, shiny colonies with neat edges on LB medium; and smooth, moist, off-white colonies on Columbia blood agar medium. Gram staining revealed that the isolate was a Gram-negative, spore-free short bacillus. Biochemical tests showed that the isolate was positive for motility test, mannitol test, hydrogen sulfide test, methyl red test, citrate utilization test, gas production from glucose test, raffinose test, sorbitol test, and D-xylose test, but negative for phenylalanine test, gluconate test, indole test, Voges Proskauer (VP) test, urease test, lysine test, ornithine test, and adonitol test. The results of 16S rRNA gene sequencing showed that the gene sequence similarity between strain MF071743 and Citrobacter freundii was 99.0%. PCR results showed that this strain carries genes encoding the urease accessory proteins UreD, UreE, and UreF. Animal intragastric administration assays demonstrated that the strain caused loose stools in cynomolgus monkeys, and all C57BL/6 mice died within 72 h. Drug susceptibility test results indicated that the isolate was sensitive to 16 antibiotics, including ceftriaxone, amikacin, gentamicin, ceftazidime, and levofloxacin, while it exhibited resistance to 5 antibiotics, including ampicillin, cefazolin, vancomycin, erythromycin, and cephalexin. Conclusion A strain of Citrobacter freundii with certain drug resistance was isolated from the feces of diarrheal cynomolgus monkeys. The results of this study provide a reference for the diagnosis and treatment of gastrointestinal diseases in captive laboratory monkeys.

Key words: Cynomolgus monkey, Citrobacter freundii, Bacterial culture, Isolation and identification, Phylogenetic analysis

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