院内呼吸科下呼吸道感染病原学及耐药性结果分析

目的分析大连市第五人民医院2009年呼吸科送检1160例次痰标本细菌检查情况,为临床提供感染数据以及合理使用抗生素提供依据。方法按常规方法将临床送检的痰标本进行细菌培养、分离。使用BIO-FOSUN微生物鉴定药敏分析系统进行细菌鉴定及抗生素敏感试验。结果一年来共收痰标本1160例次,检出病原菌253例次,阳性率为21.8%。病原菌依次为肺炎克雷伯菌83株,铜绿假单胞菌57株,乙酸钙不动杆菌29株,阴沟肠杆菌14株,粘质沙雷菌13株,大肠埃希菌10株,,金黄色葡萄球菌5株等。大多数革兰阴性菌对亚胺培南较敏感,对头孢菌素类均有不同程度的耐药。革兰阳性球菌对万古霉素敏感,对其他抗生素有不同程度的耐药。结论该院呼吸科患者下呼吸道感染以革兰阴性杆菌为主,常见病原菌耐药性未呈现高水平、多重耐药情况。提示临床医生应与检验科密切配合,关注细菌感染情况,根据药敏试验结果合理选用抗生素。     

实时荧光PCR在呼吸道感染耐甲氧西林金黄色葡萄球菌检测中的临床应用

目的评价实时荧光PCR(RT-PCR)用于检测呼吸道感染耐甲氧西林金黄色葡萄球菌(MRSA)中的方法学特性,为临床快速诊断呼吸道MRSA定植或感染提供可靠循证依据。方法通过RT-PCR技术对痰液标本中金黄色葡萄球菌(SA)特异性核酸酶编码基因nuc和MRSA的特异性耐药基因mec A进行定量检测,并同时以细菌培养、鉴定和MRSA耐药表型确诊实验作为参考方法,评价其灵敏度、特异度、阴阳性预测能力;用10倍梯度稀释法配制已知标准菌株菌悬液评估RT-PCR的最低检出限。结果 RT-PCR法较细菌培养法对MRSA检测的总符合率为97.5%,检测SA的敏感度为97.2%、特异度为98.2%、阳性预测值为92.1%、阴性预测值为99.4%,检测甲氧西林耐药性的敏感度为100%、特异度为97.7%、阳性预测值为85.2%、阴性预测值为100%;RT-PCR对nuc基因和mec A基因的最低检出限均为103/m L。结论RT-PCR法与细菌培养法对于检测MRSA差异无统计学意义,且灵敏度优于后者,是用于临床快速排除性筛查呼吸道感染MRSA的较佳检测方法。     

Role of IgA versus IgG in the control of influenza viral infection in the murine respiratory tract

The roles of IgG and secretory IgA in the protection of the respiratory tract (RT) against influenza infection remain unclear. Passive immunization with Ab doses resulting in serum IgG anti-influenza virus Ab titers far in excess of those observed in immune mice has compounded the problem. We compared the effects of i.v. anti-influenza virus IgG and i.v. anti-influenza virus polymeric IgA (pIgA) mAb administered in amounts designed to replicate murine convalescent serum or nasal Ab titers, respectively. A serum anti-influenza virus IgG titer 2.5 times the normal convalescent serum anti-influenza virus IgG titer was required for detectible Ab transudation into nasal secretions, and a serum IgG titer 7 times normal was needed to lower nasal viral shedding by 98%. Anti-influenza virus pIgA at a nasal Ab titer comparable to that seen in convalescent mice eliminated nasal viral shedding. The RT of influenza-infected pIgA- or IgG-protected mice were studied by scanning electron microscopy. Only pIgA was found to prevent virally induced pathology in the upper RT, suggesting that IgG did not prevent viral infection of the nose, but neutralized newly replicated virus after infection had been initiated. In contrast, IgG, but not pIgA, was found to prevent viral pathology in the murine lung. Our results help to resolve the controversy of IgA- vs IgG-mediated protection of the RT; both Abs are important, with plasma IgG Ab serving as the back-up for secretory IgA-mediated protection in the nasal compartment, and IgG being the dominant Ab in protection of the lung.     

Selective infection of lower respiratory tract by respiratory viruses in children with recurrent respiratory tract infections.

Thirty preschool children presenting with recurrent respiratory infections and their unaffected siblings were observed prospectively for a year. The index children experienced more episodes of acute respiratory infection than their siblings. Respiratory viruses were the major cause of respiratory infections. The index children had lower respiratory tract disease, predominantly wheeze, during 34% of proved respiratory virus infections compared with 11% of such infections experienced by the control children (p less than 0.02). Atopic children had an increased tendency to wheeze that did not reach significance, but atopy was not associated with increased susceptibility to respiratory infections.     

ICU患者呼吸道感染病原菌的分布及耐药性监测

目的了解华中科技大学同济医学院附属同济医院ICU患者呼吸道感染病原菌的分布及细菌耐药性特征,指导临床合理、科学地使用抗菌药物,为有效控制危重患者肺部感染提供依据。方法回顾分析该院2004年1月至2008年12月ICU患者呼吸道感染的病原菌分布情况,并分析其耐药性变化。结果该院ICU患者呼吸道感染病原菌主要为鲍曼不动杆菌(aba)、铜绿假单胞菌(pae)和金葡菌(sau),其中泛耐药菌株有增多趋势。耐苯唑西林金葡菌(MRSA)的检出率在77.5%~100%。药敏数据显示,pae对常用抗菌药物耐药率均较高,在25.5%~95.3%;aba仅对头孢哌酮/舒巴坦耐药率低,为12.2%,但中敏率较高,为41.7%,对其他常用抗菌药物耐药率均较高。MRSA对所有的β-内酰胺类抗菌药物均耐药,苯唑西林敏感的金葡菌(MSSA)对青霉素和红霉素耐药率较高,分别为97.1%和47.2%,对其他常用抗菌药物较敏感。结论该院ICU患者呼吸道感染以aba、pae和sau为主,且耐药现象严重,对临床常用抗菌药物有多重耐药现象,临床医生应根据药敏结果合理使用抗菌药物。     

活动性肺结核合并下呼吸道感染的致病菌群分析

目的 通过对活动性肺结核合并呼吸道感染的住院患者痰样检测观察,探讨肺结核住院患者下呼吸道致病菌种的分布及药物敏感情况.方法 选取大连市结核病医院1999年1月至2002年1月间住院的活动性肺结核同时合并下呼吸道感染患者164例,对患者晨起漱口后咯出气管深部痰液,置于无菌器皿内及时送检.接种于血平板和伊红美兰平板内24 h后观察,然后按细菌学特征鉴定,及进行抗菌药物体外药敏试验并列表分析.结果 本组肺结核住院患者以Gˉ菌引起的下呼吸道感染为主,占71.8％,真菌感染占28.7％,厌氧菌感染占4.6％,G+球菌占3.8％.单纯感染者59例,占36.0％;伴两种(或两种以上)细菌生长属混合感染105例,占64.0％.结论 肺结核住院患者下呼吸道致病菌种以Gˉ菌为主,真菌感染次之,感染者多为老年复治患者.分析反复发病原因,既往应用多种抗痨药物及抗生素,造成菌群失调导致二重感染.绝大多数肺结核患者营养状况差,住院时间长,极易造成院内感染.菌株检出率相对偏高,且混合感染多.     

Multiplex PCR analysis for species specific express-identification of orthopoxviruses

A method for one-stage rapid identification of the four orthopovirus species, which are pathogenic to humans, involving multiplex polymerase chain reaction (MPCR) was developed. Five pairs of oligonucleotides primers were simultaneously used in the mentioned MPCR assay of orthopoxvirus DNA; one of the pairs was genus-specific, the remaining four primers were species-specific for variola, monkey-pox, cowpox and vaccine-pox. The specificity and sensitivity of the developed method were evaluated through analyzing the DNA samples of 55 orthopoxvirus strains, including samples isolated from human clinical materials.     

下呼吸道真菌感染的临床特点及耐药性分析

目的探讨住院患者下呼吸道真菌感染的临床特点,对其耐药性进行分析,以指导临床合理用药。方法回顾性调查2008年1月至2009年12月间安徽医科大学第一附属医院发生下呼吸道真菌感染的病例,并进行统计学分析。结果 374例下呼吸道真菌感染患者检出白色念珠菌253例(67.6%),光滑念珠菌74例(19.8%),热带念珠菌28例(7.5%),克柔念珠菌10例(2.7%),其他假丝酵母菌3例(0.8%),毛霉菌4例(1.1%),烟曲霉菌2例(0.5%)。本组资料药敏结果显示各种真菌对多种抗真菌药物敏感率较高,其中两性霉素B、伏立康唑和氟康唑的敏感率较高,而伊曲康唑的耐药率最高,达到12.2%。结论下呼吸道真菌感染仍以白色念珠菌感染为主,光滑念珠菌和热带念珠菌其次,3种念珠菌占总分离真菌的94.9%,5种抗真菌药物的耐药率以伊曲康唑最高,社区获得性感染患者预后明显优于医院感染患者。     

Upper respiratory tract infection in mouse and rats

Summary Spontaneous aspergilloma in the para-nasal cavities of 2 rats, and a chronic granuloma with grains, caused by Gram-positive cocci in the maxillary sinus of a mouse, are reported.     

Recovery from a viral respiratory tract infection. IV. Specificity of protection by cytotoxic T lymphocytes

Immune spleen cells enhanced for influenza-specific cytotoxic activity after exposure to virus-infected stimulator cells in vitro effect recovery when transferred to nude and immunocompetent mice with influenza pneumonia (5). This protective effect correlated with the virus-specific cytotoxic activity of the transferred lymphocytes and is removed by treatment with anti-0 serum and complement. The experiments presented here indicate that spleen cells taken directly from mice undergoing a primary or secondary infection are less protective than immune spleen cells that are restimulated in vitro before transfer. This decreased ability to clear pulmonary virus and effect survival correlated with their relatively lower levels of influenza-specific cytotoxicity. Protection did not correlate with the level of natural killer cell activity of transferred cells. The results also indicate the immune spleen cells that are protective are influenza A subtype cross-reactive and are H-2-restricted; H-2d immune spleen cells effected recovery of H-2d but not H-2k challenged mice.     

High viral load of human bocavirus correlates with duration of wheezing in children with severe lower respiratory tract infection

Background

Human bocavirus (HBoV) is a newly discovered parvovirus and increasing evidences are available to support its role as an etiologic agent in lower respiratory tract infection (LRTI). The objective of this study is to assess the impact of HBoV viral load on clinical characteristics in children who were HBoV positive and suffered severe LRTI.

Methods

Lower respiratory tract aspirates from 186 hospitalized children with severe LRTI were obtained by bronchoscopy. HBoVs were detected by real-time PCR and other 10 infectious agents were examined using PCR and/or direct fluorescent assay.

Results

Thirty-one patients (24.6%) were tested positive for HBoV in the respiratory tract aspirates. Fifteen samples had a high viral load (>10⁴ copies/mL) and the other sixteen samples had a low viral load (<10⁴ copies/mL). The duration of presented wheezing and hospitalization was longer in children with high viral load of HBoV than that in children with low viral load. The days of wheezing showed a correlation with viral load of HBoV.

Conclusion

We confirmed that HBoV was frequently detected in patients with severe LRTI. Wheezing was one of the most common symptoms presented by patients with positive HBoV. A high HBoV viral load could be an etiologic agent for LRTI, which led to more severe lower respiratory tract symptom, longer duration of wheezing and hospitalization.     

急性下呼吸道感染患儿中RSV的分离鉴定及分析

目的对2015年兰州单中心急性下呼吸道感染患儿中呼吸道合胞病毒(respiratory syncytial virus,RSV)进行分离鉴定及分析。方法收集临床急性下呼吸道感染患儿痰分泌物226份,在HEP-2细胞中连续盲传培养3代,收获的培养物用半巢式RT-PCR进行检测,选取强阳性样品进行测序以确定其型别,并对其流行病学特征进行分析。结果 226份样品中RSV阳性样本为76份(阳性率为34%)。RSV阳性患儿中,男女性别比为3∶1;年龄分布6月龄患儿占45%,6月龄~2岁占35%,2~5岁的占20%。冬季为发病高峰。76例RSV阳性患儿中,临床诊断依次为毛细支气管炎31例(40.79%)、喘息性支气管炎21例(27.36%)、支气管肺炎20例(26.32%)和支气管哮喘4例(5.26%)。40份强阳性RSV样品经测序确定为B亚型。结论 RSV是引起婴幼儿急性下呼吸道感染的重要病原之一,2015年RSV的流行株主要为B亚型。     

130例嗜麦芽窄食单胞菌下呼吸道感染的药敏分析

目的探讨嗜麦芽窄食单胞菌下呼吸道感染的耐药情况。方法对自2002年5月～2004年5月分离出的130株嗜麦芽窄食单胞菌的药敏试验结果进行分析。结果嗜麦芽窄食单胞菌对常用抗生素广泛耐药,其中对亚胺培南100％耐药,对1、2、3代头孢大多数耐药．但对复方新诺明、替卡西林-克拉维酸钾和头孢他啶的敏感率分别为71．2％、64．0％和54．4%。结论嗜麦芽窄食单胞菌对常用抗生素广泛耐药．但对复方新诺明、替卡西林-克拉维酸钾和头孢他啶有较高的敏感性．可做为临床治疗嗜麦芽窄食单胞菌下呼吸道感染的有效抗菌药物。     

Antibiotics in bacterial acute respiratory tract infection in children]

The data on changes in the susceptibility of the most frequent respiratory tract pathogens i.e. Pneumococcus spp. and Haemophilus influenzae within the last 15 years and Streptococcus spp., Staphylococcus spp. and Moraxella spp. at the present time as well as recommendations based on the original and some literature data on the choice of the antibacterial drugs for the initial treatment of bacterial complications of acute respiratory tract viral infections such as otitis, sinusitis and pharyngitis are presented. The necessity of decreasing the unjustified use of antibiotics in cases of uncomplicated acute respiratory tract viral infections is indicated.     

High avidity CD8+ T cells are the initial population elicited following viral infection of the respiratory tract

Following intranasal administration, the model paramyxovirus simian virus 5 (SV5) establishes an infection in the respiratory tract of mice, which is subsequently cleared by CD8+ T cells. In this study, we sought to understand the maturation of the antiviral immune response over time by assessing the functional avidity of the responding T cells and the expansion of immunodominant populations. Surprisingly, we determined that the initial response to Ag at day 3 (d3) in the mediastinal lymph node was exclusively high avidity. However, by d5 postinfection, low avidity cells were approximately 50% of the responding T cell population. Following secondary exposure to SV5, high avidity CD8+ T cells again are the exclusive cell type present at early times postinfection (d2). Similarly, high avidity cells were preferentially elicited at d3 following infection with the unrelated vaccinia virus. We also made the observation that the immunodominance profile has not been established at d3 postinfection with SV5. However, by d5 a clear immunodominance pattern arises and is permanently maintained. These data indicate that high avidity cells are the predominant population responding at early times postinfection following respiratory infection with SV5 or vaccinia virus. However, as the response progresses, low avidity cells are activated/expanded to a greater extent compared with high avidity cells.