基于高场不对称波形离子迁移谱技术的细菌培养液检测

目的:利用高场不对称波形离子迁移谱(FAIMS)技术检测并识别常见伤口感染细菌。方法:在合适的实验条件下,用FAIMS分析仪检测大肠杆菌(ECO)、金黄色葡萄球菌(SAU)、铜绿假单胞菌(PAE)的TH肉汤培养液及纯TH肉汤培养液4种样品,得到其离子迁移谱图。分析谱图形状,提取峰值点,通过对比分析确定3种细菌TH培养液的特征离子峰。结果:ECO与SAU均有有别于另外3种样品的稳定特征离子峰,特征峰可用场强、补偿电压、离子电流值3个参量确定。PAE出现两个特征峰,其中一个不稳定出现,但依然可凭借第二个特征峰进行辨别。结论:FAIMS技术可对ECO、SAU、PAE这3种常见细菌的TH肉汤细菌培养液进行甄别,为伤口感染的快速检测提供一定的可行性。     

常见伤口感染细菌高场不对称波形离子迁移谱识别算法

目的:使用模式识别算法对常见伤口感染细菌（大肠杆菌、金黄色葡萄球菌、铜绿假单胞菌）TH肉汤培养液及纯TH培养液的高场不对称波形离子迁移谱（FAIMS图谱）进行分类识别。 方法:使用FAIMS分析仪收集了4种样品的训练及测试样本。预处理后,用主成分分析和线性判别分析对样本进行降维和特征提取,得到了训练集和测试集的空间三维分布模型,再用最近邻规则算法进行样本识别。 结果:特征提取后,正负模式样本均具有良好的分离效果,并且正模式可分性明显优于负模式。当K取合适的值时,正负模式识别率分别可达90%和70%以上。对于本文的数据模型,K取值等于或最接近每类样本数的奇数为最佳。 结论:该种算法可用于常见伤口感染细菌肉汤培养液FAIMS图谱的分类及识别。     

电子鼻检测常见伤口感染细菌实验研究

为了进一步探讨电子鼻用于伤口细菌感染快速筛查的可能性,使用自制电子鼻检测鲍曼不动杆菌、大肠杆菌、肺炎克雷伯杆菌、金黄色葡萄球菌、铜绿假单胞菌的巯基乙酸酯（TH）培养液及纯培养液,经过预处理后,使用支持向量机、BP神经网络、逻辑回归3种算法进行分类。结果显示,使用BP算法,总体识别率可达93%以上。对于单个识别率,检测大肠杆菌、肺炎克雷伯杆菌、金黄色葡萄球菌可达98%以上,检测鲍曼不动杆菌、铜绿假单胞菌可达90%左右,表明电子鼻用于伤口感染细菌的快速检测和识别具有一定的可行性。     

电子鼻技术在医学中的应用

目的:探讨电子鼻技术方法及其在医学中的应用。方法:电子鼻是利用气体传感器阵列的响应图案来识别气味的电子系统,通常由气味取样器、气体传感器阵列和信号处理系统三部分组成。介绍了电子鼻的发展状况、论述了通用电子鼻的组成、原理及所用的传感器(金属氧化物传感器、导电型聚合物传感器、压电型传感器等)的特性及其医学检测中的应用。结果:电子鼻可用于检测肺部疾病(肺癌、肺结核)、糖尿病、尿毒症和细菌感染(厌氧菌、耳鼻喉感染细菌、不同类型的金黄葡萄球菌、伤口微生物感染)。结论:电子鼻作为一种无创的、快速诊断技术在疾病的早期诊断筛查及微生物感染的快速检测方面具有重要的临床应用价值。     

靶向光热抗菌纳米材料及其在伤口愈合中的应用研究进展EI北大核心CSCD

随着光热纳米材料的开发,基于近红外光激发的光热疗法在细菌感染的伤口治疗中显示出巨大的潜力。同时,为提高伤口感染部位的光热抗菌效果,降低光热对健康组织的高温损伤,靶向细菌策略也逐渐被应用于伤口的光热治疗中。本文分类介绍了常用的光热纳米材料及其靶向细菌策略,阐述了它们在光热抗菌治疗,尤其是在细菌感染伤口中的应用,分析了靶向光热抗菌疗法在伤口愈合应用中面临的难题与挑战,最后对靶向光热抗菌材料的发展提出展望,以期为伤口光热治疗提供一条新的思路。     

分泌抗产气荚膜杆菌单克隆抗体杂交瘤细胞系的建立和初步应用

本文报道应用杂交瘤技术获得两株能持续分泌抗产气荚膜杆菌的单克隆抗体(一株抗菌体,另一株抗芽胞)的杂交瘤细胞系。在自行设计的微量点样玻片上应免疫荧光法检测杂交病培养上清,发现与产气荚膜杆菌菌体或芽胞呈特异性反应而不与其他细菌起反应。杂交病上清抗体效价为1∶16,腹水效份为1∶1×10~4。Ig亚类鉴定均为IgG_2a。抗体能特异地被细菌吸收,并有一定的抑菌作用和动物保护作用。应用此抗体对22例战伤伤口进行检测,15例检出产气荚膜杆菌与厌氧培养无明显差异,而特异性高,检测时间大大缩短,因而有可能作为早期明确伤员有无产气荚膜杆菌感染的诊断试剂。     

粉尘螨抗细菌活性物质的分离与鉴定

目的从粉尘螨丙酮提取液中分离抗细菌活性成分,并对其抗菌活性进行初步鉴定。方法用丙酮抽提粉尘螨,并用Sephadex G50分子筛层析进行对粉尘螨提取液中的抗细菌活性进行初步分离、纯化。对各组分的抗细菌活性进行初步鉴定。结果经Sephadex G50分子筛层析分离得到Ⅰ及Ⅱ两个峰。粉尘螨丙酮粗提物对绿脓假单胞菌无抑制作用,但对金黄色葡萄球菌、枯草芽孢杆菌及短小芽孢杆菌均有抑制作用。峰Ⅰ及峰Ⅱ则对大肠埃希杆菌、枯草芽孢杆菌、短小芽孢杆菌及金黄色葡萄球菌都有抑制作用。粉尘螨粗提液及第二个峰在加热及蛋白酶K处理后仍然保留抗细菌活性,但是第一个峰在同样处理后失去了抗菌活性。结论首次从粉尘螨分离纯化得到抗细菌成分。     

心脏外科术后多重耐药细菌感染的病原学特征与耐药性分析

目的了解心脏外科术后患者多重耐药菌(multidrug-resistant organism, MDRO)感染的病原学特征以及耐药模式, 指导临床医生合理应用指南推荐的抗菌药物, 提高经验性抗菌治疗的成功率、改善住院患者预后。方法收集2018年1月—2021年10月心脏外科术后409例确诊为医院感染患者的完整病历资料, 根据合格的临床标本阳性培养结果分为多重耐药细菌感染组(MDR=176例)和非多重耐药细菌感染组(non-MDR=233例), 分析MDRO感染的病原学特征以及对临床常用抗菌药物的耐药模式, 同时对不同的外科手术类型和临床感染类型相对应的病原学分布、耐药情况以及临床结局进行统计分析。结果合格的临床标本检出多重耐药细菌306株, 97例(97/176, 55.1%)患者同时存在两种及两种以上多重耐药细菌感染, 主要表现为肺炎克雷伯菌、鲍曼不动杆菌和(或)铜绿假单胞菌混合感染, 其中包括碳青霉烯类耐药细菌213株(213/306, 69.6%)。无论外科手术类型和临床感染类型如何, 病原学分布均以鲍曼不动杆菌(114/306, 37.3%)最常见, 其次是肺炎克雷伯菌(72/...     

1例帕金森患者下肢静脉溃疡的伤口护理

总结1例帕金森患者下肢静脉溃疡的伤口护理。对伤口感染清创期、肉芽生长修复期等不同时期进行充分评估,基于湿性愈合理念,选用水凝胶、藻酸盐敷料、亲水纤维银离子敷料、有边泡沫敷料应用于伤口愈合的不同阶段,为创面创造湿性愈合环境,同时辅以冷激光照射、压力治疗。伤口处理33 d后,面积明显缩小,基底100%红色肉芽组织,创周上皮化明显。     

同种异体骨移植后排斥反应的伤口处理:传统换药与负压封闭引流

背景:对于同种异体骨移植后排斥反应引起的伤口持续渗液,采用传统换药方式处理存在频繁换药、不能完全封闭伤口等问题。目的:对比传统换药与负压封闭引流处理同种异体骨移植后排斥反应引起伤口渗液的效果。方法:选择同种异体骨移植后发生排斥反应引起的伤口渗液患者45例,按患者意愿分为两组治疗,试验组27例,采用负压封闭引流技术治疗,对照组18例按传统换药处理。对比两组换药次数、创面愈合时间及伤口感染率。结果与结论:试验组平均换药次数为1.22次,伤口平均愈合时间为16.26 d,伤口感染率为4%;对照组平均换药次数为9.78次,伤口平均愈合时间为21.06 d,伤口感染率为28%。两组间换药次数、伤口愈合时间及伤口感染率比较差异有显著性意义(P0.05)。提示采用负压封闭引流技术治疗同种异体骨移植后发生排斥反应引起的伤口渗液,可减少换药次数,缩短伤口愈合时间,降低感染发生率。     

广州市2例人感染猪链球菌病的流行病学调查

目的查明广州市2例人感染猪链球菌病的感染来源、流行特征,为预防控制疫情提供依据。方法采用流行病学调查方法进行回顾性调查和现场调查,采集脑脊液标本进行细菌培养、分离,用PCR进行鉴定。结果患者均有明显的生猪接触史且首例患者手部有伤口,起病急,全身中毒症状明显,病程进展迅速,均为脑膜炎型。患者脑脊液分离培养出猪链球菌经生化和PCR检测结果为猪链球菌Ⅱ型,病人经及时治疗均痊愈出院。结论2例病例均为人感染猪链球菌病（Ⅱ型）实验室确诊病例,为散发疫情,相互间无流行病学关联,传播途径可能为接触被猪链球菌污染的生猪肉。     

Rapid flow cytometric bacterial detection and determination of susceptibility to amikacin in body fluids and exudates.

A flow cytometry-based method for rapid and quantitative detection of bacteria in various clinical specimens and for rapid determination of antibiotic effect is described. Achieving such a measurement with high sensitivity required discrimination between bacteria and other particles which were often present in clinical samples in high concentrations. This discrimination was facilitated by detecting the bacterial characteristic light scatter and fluorescence signals following staining, e.g., with the fluorescent nucleic acid-binding dye ethidium bromide, as well as by measuring bacterial proliferation during short time intervals. Antibiotic susceptibility was measured by observing the inhibition of such proliferation. The method was applied to 43 clinical specimens from various sources, such as wound exudates, bile, serous cavity fluids, and bronchial lavage. Bacterial detection, achieved in less than 2 h, agreed with results of conventional methods with a sensitivity of 74% and a specificity of 88%. Susceptibility to amikacin was detected in 1 h in 92% of 13 positive specimens.     

Hyperbranched poly(NIPAM) polymers modified with antibiotics for the reduction of bacterial burden in infected human tissue engineered skin

The escalating global incidence of bacterial infection, particularly in chronic wounds, is a problem that requires significant improvements to existing therapies. We have developed hyperbranched poly(NIPAM) polymers functionalized with the antibiotics Vancomycin and Polymyxin-B that are sensitive to the presence of bacteria in solution. Binding of bacteria to the polymers causes a conformational change, resulting in collapse of the polymers and the formation of insoluble polymer/bacteria complexes. We have applied these novel polymers to our tissue engineered human skin model of a burn wound infected with Pseudomonas aeruginosa and Staphylococcus aureus. When the polymers were removed from the infected skin, either in a polymer gel solution or in the form of hydrogel membranes, they removed bound bacteria, thus reducing the bacterial load in the infected skin model. These bacteria-binding polymers have many potential uses, including coatings for wound dressings.     

Trend survey of ocular infections with bacteria at Toyama University Hospital over the past six years--from the standpoint of laboratory examination

Specimens of bacterial ocular infections are frequently received in the clinical laboratory. However, a comprehensive trend survey of ocular infections with bacteria is very rare. Our objective is to understand the current tendency of ocular infections with bacteria in patients at Toyama University Hospital from the standpoint of laboratory examination. We studied 263 cases of ocular infection with bacteria diagnosed at Toyama University Hospital from January 2006 to December 2011. 123 were male and 140 were female, with a mean age of 61.2(0-98) years. Specimens were subjected to direct microscopy and culture. Cultures were positive in 174(66.2%) patients. The most common bacterial isolate was Staphylococcus (28.1%), followed by Corynebacterium (19.3%), Streptococcus (9.3%), and Propionibacterium (8.6%). MRSA accounted for 18.8% of all S. aureus isolates, and has increased in recent years. The number of bacteria detected was larger in March, June, July, August, and October. Age distribution indicated that around 70% of bacterial isolates were detected from patients over 60 years old. The most common specimen of ocular infections with bacteria was eye discharge (detection rate; 87.8%), followed by corneal scraping(41%), aqueous humor (19%), and vitreous body (27%). Nearly 80% of bacterial isolates were detected from patients with keratitis, endophthalmitis, dacryocystitis, and conjunctivitis. As for the disease specific detection rate, endophthalmitis was very low (38.3%). The detection rate by years indicated that the way doctors pick up the specimens greatly affects the detection rate. Based on this survey, we need close cooperation with medical doctors concerning laboratory examination in ocular infection with bacteria, and we must improve the detection sensitivity of specimens from patients with endophthalmitis.     

Protective immunization against Staphylococcus aureus infection in a novel experimental wound model in mice

A novel murine experimental wound infection model was used to assess the efficacy of multi‐component immunization against Staphylococcus aureus infection. Necrotic lesions were induced in mice with venom from Bothrops asper and infected with a low inoculum, 1 × 10² CFU. The wound infection model therefore more resembles a clinical case of S. aureus infection compared with conventional infection models where far more bacteria are required. Before infection, mice were immunized with four recombinant S.aureus proteins expressed from Escherichia coli: (i) domains 1–3 of Extracellular adherence protein (Eap), (ii) Efb – D (fusion protein combining Extracellular fibrinogen binding protein (Efb) and a fibronectin binding domain (D) of the fibronectin binding protein (FnBP) and (iii) clumping factor A (ClfA). In the immunized group, lower bacterial colonization, undisturbed crust formation and significantly faster wound healing were found compared with the unimmunized control group. Efb and Eap have previously been found to impair wound healing and neutralization of these proteins by antibodies restores a more natural wound healing process. This effect is further also enhanced by the proposed opsonic activity of antibodies against ClfA and FnBP.     

Detection of Prosthetic Hip Infection at Revision Arthroplasty by Immunofluorescence Microscopy and PCR Amplification of the Bacterial 16S rRNA Gene

In this study the detection rates of bacterial infection of hip prostheses by culture and nonculture methods were compared for 120 patients with total hip revision surgery. By use of strict anaerobic bacteriological practice during the processing of samples and without enrichment, the incidence of infection by culture of material dislodged from retrieved prostheses after ultrasonication (sonicate) was 22%. Bacteria were observed by immunofluorescence microscopy in 63% of sonicate samples with a monoclonal antibody specific for Propionibacterium acnes and polyclonal antiserum specific for Staphylococcus spp. The bacteria were present either as single cells or in aggregates of up to 300 bacterial cells. These aggregates were not observed without sonication to dislodge the biofilm. Bacteria were observed in all of the culture-positive samples, and in some cases in which only one type of bacterium was identified by culture, both coccoid and coryneform bacteria were observed by immunofluorescence microscopy. Bacteria from skin-flake contamination were readily distinguishable from infecting bacteria by immunofluorescence microscopy. Examination of skin scrapings did not reveal large aggregates of bacteria but did reveal skin cells. These were not observed in the sonicates. Bacterial DNA was detected in 72% of sonicate samples by PCR amplification of a region of the bacterial 16S rRNA gene with universal primers. All of the culture-positive samples were also positive for bacterial DNA. Evidence of high-level infiltration either of neutrophils or of lymphocytes or macrophages into associated tissue was observed in 73% of patients. Our results indicate that the incidence of prosthetic joint infection is grossly underestimated by current culture detection methods. It is therefore imperative that current clinical practice with regard to the detection and subsequent treatment of prosthetic joint infection be reassessed in the light of these results.     

广州市一起登革热家族聚集性暴发事件的调查与分析

目的探讨登革热家庭聚集性发病的流行病学特点及传播效率，为今后进行有效的预防和控制登革热暴发提供参考。方法采用现场流行病学调查方法对广州市一起登革热家庭聚集性暴发事件进行调查和分析；采用ELISA、RT-PCR和病毒分离的方法对标本进行检测。结果2006年8月广州市荔湾区发生一起登革热家庭聚集性暴发事件，该家族15名家庭成员先后共有6人发病，罹患率40．0％，其中6例患者登革热抗体IgM或IgG阳性3例，病毒分离阳性3例，荧光PCR检测阳性者1例，基因序列测序和病毒分离结果最终确定为登革I型病毒。结论根据临床表现、实验室检测结果以及流行病学调查．虽然该家族部分患者登革热抗体为阴性，但病例发病均在一个最长潜伏期内，因此可以确定该家族发生了登革热聚集性暴发，荔湾区龙津中路龙兴里最有可能是共同感染地．感染来源不明，感染时间为家庭聚会日可能性大。     

Association between bacterial colonization on the tumor, bacterial translocation to the cervical lymph nodes and subsequent postoperative infection in patients with oral cancer

Objective: To investigate the association between postoperative infection, bacterial translocation to the cervical lymph nodes and bacterial colonization on the tumor in oral cancer patients.
Methods: Twenty-one oral mucosal cancer patients (11 male and 10 females: mean age 68.6 years) were studied. They underwent tumor surgery and neck dissection with free flap reconstruction. Ampicillin 1 g was parenterally administered from the start of the surgery as prophylaxis. Isolates from cervical lymph nodes, tumor and postoperative infected wound were studied microbiologically and pathologically.
Results: Bacterial translocation was found in 52 lymph nodes (52/107: 48.6%). Viable bacteria were isolated from 20 tumors (95.2%). Oral microflora and enteric bacteria were isolated. Postoperative infection was found in four cases. In three cases, enteric bacteria ( Klebsiella, Enterobacter, Enterococcus ) isolated from postoperative infections were also found in the tumor or the lymph nodes.
Conclusions: The operative field in oral cancer surgery was colonized by the indigenous flora and enteric bacteria. These were recovered not only from the tumor surface but also from the cervical lymph nodes. Preoperative surveillance culture or tumor culture have value in predicting the bacteriology of postoperative infection, and in selecting the appropriate antibiotic treatment.     

Anatomical and immunological responses of rabbit gallbladders to bacterial infections.

To study the sequential morphological and immunological response of the rabbit gallbladder to bacterial infection and to compare the inflammatory responses with different pathogens, gallbladders were infected with Streptococcus faecalis and two strains of Escherichia coli, one of which produced enterotoxin. Gallbladder infection was produced either by intravenously injecting bacteria into rabbits with a small liver infarct or by injecting bacteria directly into the gallbladder of normal rabbits. The percentage of gallbladders infected intravenously with a nonenterotoxigenic E. coli strain was 86% at 1 week, 70% at 3 weeks, and 15% at 6 weeks. Epithelial necrosis and leukocyte infiltration were prominent 1 week after infection. At 3 and 6 weeks after infection, there was crypt distortion and increased mucus secretion in the epithelium as shown by periodic acid-Schiff staining. The lamina propria was infiltrated with mononuclear cells, many of which were plasma cells. Myofibroblasts (contractile fibroblasts) were also identified on transmission microscopy, In addition to these changes, toxigenic E. coli produced subepithelial capillary dilation in the villus core. Morphological changes (excluding toxin-associated changes) were related to the duration of infection rather than to the specific species of infecting bacteria. Infected gallbladders studied by immunofluorescence had a greater than 50-fold increase in plasma cells compared with control cells. In addition, the number increased with the duration of infection. Immunoglobulin A cells were the major cell type in gallbladders infected by intravesical injection, whereas immunoglobulin G cells predominated in gallbladders infected intravenously. The gallbladder appears to mount a local immune response to bacterial infection.