Hemorrhagic blisters in fulminant Aeromonas hydrophila bacteremia: Case report and literature review

The Aeromonas species, belonging to the family Aeromonadaceae, are opportunistic pathogens found in humans with an incidence rate of 76 cases per million inhabitants in Southern Taiwan.The incidence of Aeromonas septicemia is relatively low, accounting for less than 15% of cases.Patients diagnosed with Aeromonas hydrophila bacteremia who were presented with skin blisters and septic shock have been reported to have a mortality rate of 100%.Aeromonas infection must be considered in the differential diagnosis of gangrene-like tissue damage or skin lesions in patients with end-stage renal disease, due to the potential sources of infections.A 49-year-old Taiwan Residents diabetic woman with end-stage renal disease had underwent regular hemodialysis.She was referred to our hospital due to a one-day course of fever, dyspnea, hypotension, and fulminant hemorrhagic blisters covering her whole body.A physical examination uncovered multiple hemorrhagic blisters, along with a ruptured blister over the lower left leg.Laboratory tests revealed an elevation of liver enzymes, impaired renal function, lactatemia, and high anion-gap metabolic acidosis.Cultures of both blood and hemorrhagic blister fluid grew Aeromonas hydrophila.However, she experienced persistent shock despite aggressive intravenous fluid, empiric antibiotics, and inotropic agents with norepinephrine and dopamine.Early diagnosis and prompt management using intravenous fluids, antibiotics and surgical debridement is recommended in order to improve a patient's survival rate.

一起混合性气单胞菌引起食源性疾病暴发的病原学检测

目的探究引起细菌性食源性疾病暴发的病原学原因,了解气单胞菌污染食品引起聚集性事件的特征,为类似事件的调查处置提供参考。方法采集本起疫情患者肛拭子、食品留样、食品加工工具涂抹样,参照《食品卫生微生物学检验》《全国临床检验操作规程》(第四版)进行检验。结果在小黄鱼食物留样和两名患者肛拭子中,检出温和气单胞菌。在一份厨房用具涂抹液和其中一名患者肛拭子中,检出嗜水气单孢菌。结论这是一起罕见的混合性气单胞菌引起的食源性疾病暴发事件,提示我们在肠道感染性腹泻的诊治过程中,除了考虑常见肠道致病菌外,气单胞菌等罕见致病菌也不容忽视,以免给临床诊断和治疗带来困扰。

枯草芽孢杆菌对三种水产动物病原菌体外拮抗作用的研究

为探明枯草芽孢杆菌BHI344菌株对水产养殖动物病害的生物防治功能,本文采用枯草芽孢杆菌与病原菌共同培养的方法,就枯草芽孢杆菌对三种水产动物病原菌(嗜水气单胞菌、温和气单胞菌、豚鼠气单胞菌)的体外拮抗作用进行了研究。结果表明:枯草芽孢杆菌BHI344菌株对三种水产动物病原菌都存在明显的拮抗作用,并随着枯草芽孢杆菌初始接种浓度的升高,以及培养时间的增长,拮抗作用越明显。

中国对虾败血病病原菌（气单胞菌）的致病性与生物学性状

本文从患败血病的中国对虾的血淋巴中分离到嗜水气单胞菌和豚鼠气单胞菌，经人工感染试验证实为此败血病的病原菌。两种病原菌均为革兰氏阴性、极生单鞭毛能运动的短杆菌，在ＴＣＢＳ上不生长，对Ｏ／１２９不敏感．在不含ＮａＣｌ的基础培养基上能生长。氧化酶、过氧化氢酶阳性，利用蔗糖、麦芽糖和淀粉产酸不产气，利用果糖、甘露醇、半乳糖和密二糖产酸产气，不发酵乳糖、肌醇、山梨醇、木糖、蕈糖等，精氨酸双水解、色氨酸脱氨阳性。嗜水气单胞菌发酵葡萄糖产气、Ｖ－Ｐ反应、柠檬酸盐利用、Ｈ２Ｓ产生均为阳性；而豚鼠气单胞菌的上述反应均为阴性。

3例血透患者发生嗜水/豚鼠气单胞菌感染的MDT分析

目的降低医院感染发生率,防止医院感染暴发。方法感染管理部组织医务部、护理部、医学工程部、后勤部、感染性疾病科、检验科、药学部相关专家开展MDT讨论,分析3例血透患者发生嗜水/豚鼠气单胞菌感染的各个环节,采取相应的措施并启动应急预案。结果3例血透患者出现嗜水/豚鼠气单胞菌感染的原因与患者的生活习惯、抵抗力低、接触感染有较大的关系。结论开展MDT活动能够拓宽医务人员思路,规范血透患者感染管理以及发生感染后处理的各个环节。

嗜水气单胞菌WQ中PHBHHx的合成及其分子基础研究

Aeromonas hydrophila WQ isolated from lake water was found to be able to synthesize polyhydroxyalkanoates (PHA) copolymer consisting of 3-hydroxybutyrate (HB) and 3-hydroxyhexanoate (HHx) (PHBHHx). Lauric acid was found to be the most suitable carbon source for cell growth and PHBHHx accumulation. The bacteria accumulated 49% PHBHHx containing 6% HHx in terms of cell dry weight when grown on lauric acid for 72 h. 42% PHBHHx consisting of 14% HHx was obtained with 5 g/L glucose and 10 g/L lauric acid as co-substrate. Higher glucose concentration greatly reduced the cell concentration and PHA content. The PHA biosynthesis genes from A. hydrophila WQ was successfully cloned using a two-step PCR cloning strategy based on PHA biosynthesis genes organization of Aeromonas caviae. A. hydrophila WQ and A.caviae shared high identities in the PHA gene loci, namely, ORF1, phaC and phaJ had 100%, 97% and 97.5% identities respectively. PHA synthases of A. caviae and A. hydrophila were proposed to contain type IV PHA synthases which are different compared with type I PHA synthases on the substrate specificity and location arrangement of PHA metabolic genes.

食品与环境中豚鼠气单胞菌系统发育分析以及毒力和耐药性研究

目的食品与环境中49株豚鼠气单胞菌菌种鉴定、毒力与耐药性检测。方法VITEK、API 20NE生化鉴定,gyrB、rpoD系统发育分析;PCR检测act、alt、ast、lip、ahp、aerA、hlyA、ompA1、fla基因;AST-GN16药敏试验。结果生化鉴定为豚鼠/嗜水气单胞菌株54株,经系统发育分析豚鼠气单胞菌49株,嗜水气单胞菌4株,中国台湾省气单胞菌1株。毒力基因alt、lip、ompA1、fla、act、aerA、hlyA检出率依次为100.00%、100.00%、79.59%、14.29%、2.04%、2.04%、2.04%,未检出ast、ahp;存在4种毒力基因组合,优势组合为alt/lip/ompA1(32/49)。豚鼠气单胞菌氨苄西林、头孢唑林、头孢西丁、阿莫西林/克拉维酸、头孢曲松、复方新诺明、安曲南耐药率依次为79.59%、14.29%、10.20%、6.12%、4.08%、4.08%、2.04%,哌拉西林/他唑巴坦、亚胺培南、阿米卡星、庆大霉素、左氧氟沙星、替加环素、呋喃妥英均敏感;2株多重耐药菌株。结论gyrB、rpoD可有效鉴定豚鼠/嗜水气单胞菌,rpoD可区分近亲缘关系豚鼠与中国台湾省气单胞菌;所有豚鼠气单胞菌均携带2种以上毒力基因,1株环境源菌携带7种毒力基因;青霉素类普遍耐药,产生β-内酰胺酶是最主要耐药机制;未发现碳青霉烯类、氨基糖苷类、氟喹诺酮类、四环素类、呋喃类耐药菌株;食品和生活饮用水存在多重耐药菌。