应用噬菌体控制假单胞菌的研究进展

假单胞菌属细菌中的部分菌株是动植物和人类的致病菌，也是食品的腐败菌，会导致动植物和人类的高死亡率和严重的食品安全事故。噬菌体作为一种细菌性病毒，特异性高、自我增殖快且无副作用。这些特性使其成为了解决细菌性问题的新思路和新方法。本文就利用噬菌体防控假单胞菌属致病菌和腐败菌在食品、水产、植物、医疗等方面的研究和应用进行综述，以便为后期的深入研究提供一定的参考。     

Association between commensal bacteria and opportunistic pathogens in the dental plaque of elderly individuals

Opportunistic infections in the oral cavity of the elderly may increase the incidence of systemic disease. The objective of this study was to investigate the differences in the oral bacterial flora between dependent elderly (inpatients) and independent elderly (community-dwelling residents). After multiple variables were taken into account, inpatients had significantly lower detection rates than community-dwelling residents for alpha-streptococci (p < 0.001) and Neisseria (p 0.004), and higher detection rates for Pseudomonas aeruginosa (p 0.024), methicillin-resistant Staphylococcus aureus (MRSA) (p 0.011) and Actinomyces spp. (p 0.005). Among inpatients, the requirement for a high degree of care was related negatively to detection of alpha-streptococci, but was related significantly to detection of P. aeruginosa (p 0.018) or MRSA (p 0.004). Tube-fed inpatients had a significantly lower detection rate for alpha-streptococci (p 0.041) and a higher detection rate for P. aeruginosa (p 0.004) than those who did not require tube feeding. Inpatients with a history of antibiotic use had a significantly lower detection rate for alpha-streptococci (p 0.049) and a higher detection rate for MRSA (p 0.007) than those without a history of antibiotic use. The detection rates for P. aeruginosa or MRSA in inpatients without alpha-streptococci were higher than in inpatients with alpha-streptococci after controlling for age and gender (P. aeruginosa, p 0.006; MRSA, p 0.001). Overall, detection of alpha-streptococci had an inverse correlation with the detection of P. aeruginosa and MRSA in the oral cavity and is likely to be an indicator of pathogenic bacterial infection.     

聚合酶链反应检测铜绿假单胞菌感染性角膜溃疡的实验研究及临床应用

目的：探索聚合酶链反应（PCR）技术对铜绿假单胞菌感染性角膜溃疡快速诊断的可行性。优越性及其在临床应用中的价值。方法：建立PCR检测标准铜绿假单胞菌方法，对兔铜绿假单胞菌感染性角膜溃疡模型研究并应用于临床，并与细菌培养做比较。结果：铜绿假单胞菌扩增出一条长504bp的阳性条带，其他常见细菌，人和兔正常角膜组织均为阴性，动物模型PCR敏感性为93.8%。特异性为100.0%；细菌培养敏感性为68.7%。特异性为93.7%。临床标本PCR阳性率为66.7%；细菌培养阳性率为38.1%。结论：PCR技术对快速检测实验室和临床标本中的铜绿假单胞菌具有重要的应用价值。     

糖对椰酵假单胞菌产毒性能的影响研究

以半固体ＬＡ和营养琼脂为基础培养基，分别加入葡萄糖、蔗糖、可溶性淀粉、甘油等４种成分，研究糖分对椰酵假单胞菌产毒性能影响。结果表明，椰酵假单胞菌在营养琼脂和ＬＡ半固体基础培养基上基本不产毒或产毒量很低，而葡萄糖和甘油的加入使椰酵假单胞菌的产毒能力大幅度提高，产毒量不低于在马铃薯葡萄糖琼脂（ＰＤＡ）中，提示了糖代谢在椰酵假单胞菌生长和产毒过程中的重要作用。建议将ＬＤＡ（含葡萄糖的ＬＡ，新设计）半固体做为一种新的椰酵假单胞菌产毒培养基，有利于实验室研究及不同实验室间的质量控制     

Bilateral Hematogenous Pseudomonas aeruginosa Endophthalmitis After Lung Transplantation

Pseudomonas aeruginosa commonly colonizes the airways of patients with cystic fibrosis (CF). However, the occurrence of bacteremia with metastatic infection to the eye causing endogenous endophthalmitis is very rare. In the setting of lung transplantation, the significance of P. aeruginosa bacteremia in patients with CF whose airways are colonized before transplantation is unknown. We report a case of bilateral P. aeruginosa endogenous endophthalmitis in a patient with CF after lung transplant without documented bacteremia. The patient presented with acute eye symptoms in the presence of a left atrial thrombus and the disease followed a rapidly progressive course requiring aggressive medical-surgical treatment. Typically P. aeruginosa endophthalmitis has been associated with a poor visual prognosis. However, with combined medical-surgical management this patient retained useful vision in one eye without having retinal detachment or requiring enucleation. Endogenous endophthalmitis should be considered in the differential diagnosis of ocular complaints in patients with CF after lung transplant.     

16株假单胞菌DNA的G＋C百分含量测定

采用改良的热变性温度法，将DNA升温及恒温处理与紫外吸收值的测定分两步进行，检测3株标准菌株和16株假单胞菌DNA的G Cmol% 含量。结果表明，14株假单胞菌与其相应标准菌种的DNAG＋Cmol%含量基本一致，与其生物学性状亦相符；另2株DNA的G＋Cmol%含量与其生物学性状不符，其分类学位置尚待探讨。     

Different opinions of physicians on the importance of measures to prevent acquisition of Pseudomonas aeruginosa from the environment

BACKGROUND: Since chronic infection with mucoid Pseudomonas aeruginosa (PA) is associated with deteriorating lung function, many parents of young children with cystic fibrosis (CF) fear the first PA positive throat swab as a milestone in the progression of the disease. To reduce the risk of PA acquisition from the environment, they perform preventive measures at home or outdoors. METHODS: In an attempt to evaluate the attitude of CF physicians towards these measures and the respective consulting practice, we mailed a questionnaire to all 65 certified paediatric CF centres in Germany. RESULTS: Physicians from 54 (83%) CF clinics replied. They expressed widely different ideas about the impact of the environment for the acquisition of P. aeruginosa, and recommended a large spectrum of preventive measures. Some physicians proposed only few precautions, which focussed on the prevention of cross-infection between patients, whereas others suggested prevention of any contact with moist or wet places, e.g. use different toothbrushes for mornings and evenings, or do without air-conditioning in the car. CONCLUSIONS: CF physicians have different opinions on the risk of PA acquisition from the environment. Doctors who recommend strict precautions could engender a parental fear of a ubiquous threat from invisible bacteria. The resulting extended safety measures might impair the family's quality of life.     

烧伤病区多重耐药铜绿假单胞菌DNA的脉冲场凝胶电泳分析

目的:了解烧伤病区铜绿假单胞菌(Pseudomonas aeruginosa,PA)感染的分子流行病学特征。方法:采用脉冲场凝胶电泳(PFGE)分型的方法,对15株分离自烧伤临床病人的多重耐药PA染色体组DNA进行分析。结果:15株检测菌株中有9株菌分别属于两种不同的PFGE图谱类型,具有同源性的菌株占测试菌株的60%。结论:导致我院烧伤患者感染多重耐药的PA中有同源性的比例较高,提示在烧伤救治中采取有针对性的措施,防止烧伤病房内的交叉感染对于降低烧伤感染率、提高烧伤救治水平具有重要意义。     

绿脓杆菌外毒素A的细胞毒性和细胞表面受体密度

用微量细胞法观察了肝癌细胞SMMC-7721,成纤维细胞L929。肺癌细胞A549及中国地鼠卵巢细胞CHOk1等4株传代细胞对绿脓杆菌外毒素A细胞毒作用的敏感性,结果SMMC-7721最敏感,L929次之,A549次于前两者,CHOk1最次,用ELISA法显示各细胞株表面绿脓杆菌外毒素A受体,且用图像分析比较受体密度,结果与细胞毒作用一致,以SMMC-7721为最高,显示了细胞毒敏感程度与受体量呈正相关。