钦州市自然流产人群肺炎链球菌携带率研究

目的探讨钦州市自然流产人群肺炎链球菌携带率状况与自然流产的相关性。方法构建基于肺炎链球菌特征目标基因lyt和ply基因的实时荧光PCR检测体系,检测自然流产人群肺炎链球菌携带率,并与常规孕检的对照组进行比较。结果自然流产组人群的肺炎链球菌特征基因检出率为15.26%,对照组的肺炎链球菌特征基因检出率为15.09%,两组比较差异无统计学意义(P0.05)。结论肺炎链球菌感染与自然流产不存在相关性,不是引起流产的主要因素,但建议孕期个体应注意预防肺炎链球菌感染,避免由此带来的不良结局。     

Source and extent of Klebsiella pneumoniae in the paper industry.

Three pulp and paper mill processing plants were evaluated for fecal coliform and Klebsiella pneumoniae bacterial concentrations. Freshwater consumed by paper industries contained minimum detectable levels of K. pneumoniae, less than 10 organisms per 100 ml. Elevated concentrations of K. pneumoniae could be traced from early pulping stages to water processing reuse systems. Concentrations of K. pneumoniae (thermotolerant and thermointolerant) ranged from 40,000 organisms per 100 ml to an estimated 3 x 10(6) organisms per 100 ml. K. pneumoniae biotyping provided evidence for the selective growth and persistence of K. pneumoniae from the initial wood washing stages through to the final effluent discharge. Wastewater treatment had limited effects in reducing K. pneumoniae concentrations. K. pneumoniae levels ranged from 40 organisms per 100 ml to an estimated 10(6) organisms per 100 ml. The presence of K. pneumoniae in water indicates degraded water quality, and its significance with regard to human health effects has yet to be examined.     

Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in pneumonia patients in four major hospitals in Trinidad

The prevalence of current Mycoplasma pneumoniae and Chlamydia pneumoniae infections in patients with pneumonia in Trinidad, and the relationship between pneumonia and risk factors were investigated. Blood samples were collected from 132 patients diagnosed by attending physicians, as suffering from pneumonia at four hospitals in Trinidad. Serum samples were tested for M. pneumoniae IgM and IgG and C. pneumoniae IgM by the enzyme immunoassay (EIA). In addition, C. pneumoniae IgM and IgG were detected using microimmunofluorescence (MIF). A comprehensive questionnaire which addressed demographic information as well as risk factors for pneumonia was administered to patients. All analyses were done using the Statistical Package for Social Sciences (SPSS), version 9. Seroprevalences of 46.0% (58 of 126) were found for C. pneumoniae Ig M/G, and 66.7% (88 of 132) for M. pneumoniae Ig M/G. The difference was statistically significant (p < 0.01; chi2). Thirty-four percent (43 of 125) for C. pneumoniae Ig M/acute Ig G and 28.8% (36 of 125) of M. pneumoniae IgM were not statistically significant (p > 0.05; chi2). Hospital, gender and ethnicity of patients did not significantly (p > 0.05; chi2) affect the seroprevalence of the bacteria assayed for. However, the prevalence of C. pneumoniae (23.3%) in patients under 21 years old compared to other age groups was statistically significant (p = 0.043; chi2). Overall, the seroprevalence to both pathogens was not significantly (p > 0.05; chi2) affected by comorbidities and signs/symptoms. It was concluded that new infections by C. pneumoniae in pneumonia patients may be an important aetiological agent for the condition in Trinidad.     

Systemic and mucosal antibody response in experimental Chlamydia pneumoniae infection of mice

Chlamydia pneumoniae is a common human respiratory pathogen, and sera from infected individuals recognize several proteins of C. pneumoniae. We produced C. pneumoniae-specific proteins in a Bacillus subtilis expression system. We then used these recombinant C. pneumoniae proteins and purified C. pneumoniae elementary bodies as antigens in enzyme immunoassays to assess the kinetics and protein specificity of the systemic and mucosal antibody responses induced by C. pneumoniae intranasal infection in BALB/c mice. The systemic antibodies in mice recognized strong 'key' immunogens of Chlamydia, Omp2 and Hsp60, but weakly targeted the MOMP protein, the major immunogen in chlamydial species other than C. pneumoniae. The IgA antibodies in bronchial secretions specifically recognized the putative surface protein of C. pneumoniae, Omp4. Our preliminary observations point to the necessity of further characterization of the mucosal antibody response during C. pneumoniae infection.     

Cytokines in Mycoplasma pneumoniae infections

Mycoplasma pneumoniae (M. pneumoniae) is one of the smallest free-living bacteria known. Along with other unique characteristics of this genus, it lacks the typical peptidoglycan cell wall of most eubacteria. Best known for causing tracheobronchitis and atypical pneumonia in humans, this pathogen also causes a number of extrapulmonary syndromes such as meningitis/encephalitis and arthritis. Recent studies also suggest that infection may be associated with chronic conditions such as asthma. Although the mechanisms of M. pneumoniae pathogenesis remain to be elucidated, one important component of M. pneumoniae infections is the induction of proinflammatory and other cytokines in both acute and chronic conditions. In this review, we survey the induction of cytokines by M. pneumoniae in different model systems, and we discuss the possible role of induced cytokines in M. pneumoniae pathogenesis.     

Protective effect of colostrum in Mycoplasma pneumoniae infection induced in infant mice

The immunological responses and mechanism of maternal immunity in Mycoplasma pneumoniae infection of mice were investigated. ICR female mice, 4 weeks old, and infant mice, 2 to 4 days old, were infected with M. pneumoniae. Anti-M. pneumoniae antibodies in serum and colostrum were determined by enzyme-linked immunosorbent assay. The specific IgG antibody production persisted for 9 months or longer in both the young and infant mice. These infected mice were protected from rechallenge with M. pneumoniae. In addition, the infected dams conferred passive immunity on their offspring. The infant mice born to uninfected normal dams were protected from the challenge with M. pneumoniae when fed by infected foster dams. Conversely, the infant mice born to infected dams were not protected from the challenge with M. pneumoniae when the infants were fed by uninfected dams. The specific IgG antibody appeared in serum of infant mice inoculated orally with M. pneumoniae-infected mouse serum and the infants were protected from challenge with M. pneumoniae, while the infants given protein A-absorbed serum were not protected from the challenge. These results suggest that one of the factors involved in the resistance of infant mice to M. pneumoniae infection is the specific IgG antibody present in the colostrum rather than the result of transplacental transfer.     

The spread of Mycoplasma pneumoniae is polyclonal in both an endemic setting in France and in an epidemic setting in Israel

Mycoplasma pneumoniae infections occur both endemically and epidemically, and macrolide resistance has been spreading for 10 years worldwide. A substantial increased incidence of M. pneumoniae infections has been reported in several countries since 2010. Whether this increased incidence is attributed to different or to the same M. pneumoniae genotype is unknown. We have developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for the molecular typing of M. pneumoniae isolates. In this study, the MLVA typing method was modified and validated to be applicable directly to respiratory tract specimens without culture. This method was applied to 34 M. pneumoniae-positive specimens received at the Bordeaux Hospital, France, between 2007 and 2010 in an endemic setting, and to 63 M. pneumoniae-positive specimens collected during an epidemic surge of M. pneumoniae infections in 2010 in Jerusalem, Israel. The M. pneumoniae endemic spread was shown to be polyclonal in France, with 15 MLVA types identified. Strikingly, the Israeli epidemic surge was also a multi-clonal phenomenon, with 18 circulating MLVA types. The macrolide resistance-associated substitution, A2058G, was found in 22% of the Israeli patients. Macrolide-resistant M. pneumoniae belonged to four MLVA types, the MLVA type Z being the most frequent one. An association between the MLVA type Z and macrolide resistance might exist since macrolide resistance was present or generated during the course of illness in all patients infected with this MLVA type. In conclusion, the discriminatory power of the MLVA showed that the spread of M. pneumoniae strains in France in an endemic setting was polyclonal as well as the surge of M. pneumoniae infections in Israel in 2010.     

Community-acquired pneumonia in adults.

Although the frequency of community-acquired pneumonia caused by Streptococcus pneumoniae continues to be high, studies show that Mycoplasma pneumoniae, Chlamydia pneumoniae, or Legionella pneumophila are the etiologic agents in 20% to 40% of community-acquired pneumonia in adults. The clinical presentation of pneumonia caused by these organisms may be indistinguishable from pneumonia due to S pneumoniae. Separation of cases of pneumonia due to S pneumoniae as typical and that caused by M pneumoniae, C pneumoniae, or L pneumophila as atypical is unwarranted and unhelpful in planning therapy. As many as 35% to 50% of patients do not have an etiologic agent identified. Community-acquired pneumonia can have high morbidity and mortality in patients who are older, have underlying lung disease, diabetes mellitus, or other comorbid conditions, or who have decreased immune function regardless of the specific etiologic agent. In choosing appropriate empiric antimicrobial therapy in hosts who are not immunocompromised, erythromycin and other macrolide antibiotics have the advantage of being effective against a wide range of pathogens likely to be encountered, including S pneumoniae, M pneumoniae, and L pneumophila, and of having some benefit against C pneumoniae. In other patients, the selection of antibiotic therapy can be based on age, clinical suspicion, epidemiologic data, and laboratory test results. Antimicrobial therapy can be directed at specific organisms when and if they are identified.     

Seroprevalence of Chlamydophila pneumoniae in ischaemic heart disease

We investigated the presence of Chlamydophila pneumoniae antibodies in 125 patients with cardiovascular disease and in 128 controls. C. pneumoniae antibodies were measured by microimmunofluorescence assay. A significantly high prevalence of IgG C. pneumoniae antibodies at titre > or = 8 was found in patients (84%) in comparison to controls (47.6%). Considering as cut-off the IgG titre > or = 32, 52% of patients with coronaropathies and 18.75% of controls resulted positive (p < 0.0001). IgA C. pneumoniae antibodies were found in patients and controls without statistically significant differences. High C. pneumoniae antibodies (titre > or = 256) were found in 11% of patients with acute myocardial infarction (AMI) and in none of the controls. In patients, the percentage of IgG and IgA seropositivity increased with age and decreased in patients aged > 70 years. Only patients with AMI are at risk of having antibodies against C. pneumoniae (OR = 6.69). None of the known risk factors for cardiovascular disease was significantly associated with C. pneumoniae seropositivity IgG. This is the first report in our area on the possible association of C. pneumoniae IgG seropositivity and acute ischemic events.     

Chlamydia pneumoniae respiratory infections in Taiwan

To understand the epidemiology of Chlamydia pneumoniae acute infections in Taiwan, we collected 116 paired and 244 single sera from patients suspected of C. pneumoniae infection and conducted microimmunofluorescence test. Eighty-three patients (83/360, 23%) met the diagnostic criteria of current C. pneumoniae infection. The C. pneumoniae infections were significantly higher in men than in women (P< or =0.0001) and were most frequent in the group of 40-49 year-olds, and the people older than 70 years old. C. pneumoniae infection often occurred in the late autumn lasting to the cold winter and in the transition period between the spring and summer.     

Immunoserodiagnosis of acute Streptococcus pneumoniae and Chlamydia pneumoniae infections in the period of epidemic rise of non-hospital pneumonia in children in St. Petersburg, 1998-2001

The dynamics of the antibody formation to S. pneumoniae and C. pneumoniae in children during the epidemic outbreak of non-hospital pneumonia in St. Petersburg in 1998-2001 was studied. For the first time the inhibiting influence of acute C. pneumoniae infection on the synthesis of antibodies to S. pneumoniae in acute mixed infection was established. The prolonged (up to days 29-39 of the disease) circulation of IgM and IgG antibodies in acute chlamydial infection, as well as the prevalence of the primary infectious process, were detected.     

1997-2010年小儿肺炎克雷伯菌耐药性变迁分析

目的 了解1997-2010年肺炎克雷伯菌(KPN)在儿科及新生儿科临床感染中的流行状况及耐药性.方法 收集珠海市妇幼保健院儿科及新生儿科1997-2010年临床痰液标本中分离的肺炎克雷伯菌共633株,分析其对常用抗生素的耐药性.并分析2005年以后产超广谱β-内酰胺酶(ESBLs)与不产ESBLs肺炎克雷伯菌株耐药性的差异.结果 根据14年来该院临床分离的肺炎克雷伯菌药敏试验结果显示,该菌对氨苄西林及哌拉西林的耐药率最高,可达100％.对头孢他啶、头孢吡肟的耐药率各年有波动,但总体无明显变化(分别约28％、34％).对儿科临床限制使用药物如庆大霉素、左旋氧氟沙星、氯霉素、复方新诺明等耐药率呈逐年下降趋势.14年来尚未发现对亚胺培南耐药的KPN.2005年以后产ESBLs菌株的检出率呈逐年增高趋势(17％ ～38.7％),且对各种抗生素的耐药率较普通KPN明显增高.结论 肺炎克雷伯菌对临床常用β-内酰胺类抗生素耐药率高,儿科限制使用药物的耐药率有逐年下降趋势,产ESBLS菌株耐药情况严重.     

Influence of temperature and relative humidity on the survival of Chlamydia pneumoniae in aerosols.

The survival of Chlamydia pneumoniae in aerosols was investigated by using a chamber with a capacity of 114.5 liters. We injected 5 x 10(7) inclusion-forming units (IFU) of C. pneumoniae in aerosols with a droplet size of 3 to 5 microns. Samples were taken after 30 s and every 1 min thereafter. The survival of C. pneumoniae was measured at four temperatures (8.5, 15, 25, and 35 degrees C) and at three different relative humidities (RH) of 5, 50, and 95% for each temperature. The survival rates of Streptococcus pneumoniae, Streptococcus faecalis, Klebsiella pneumoniae, Chlamydia trachomatis LGV2, and cytomegalovirus were also determined at 25 degrees C and 95% RH and compared with that of C. pneumoniae. At the mentioned temperatures and RH, a rapid decrease of C. pneumoniae IFU was observed in the first 30 s. After this the decrease in the number of IFU was more gradual. The survival of C. pneumoniae in aerosols were optimal at 15 to 25 degrees C and 95% RH; it was good compared with those of other microorganisms. A lower death rate was observed only in S. faecalis. In C. trachomatis, the death rate during the first 30 s was higher than that in C. pneumoniae (85 and 53.3%, respectively). After the first 30 s, the death rates in the two organisms were identical. It was concluded that transmission of C. pneumoniae via aerosols was possible. There is probably a direct transmission from person to person, taking into account the relatively short survival period of C. pneumoniae in aerosols.     

Chlamydophila pneumoniae in horses: a seroepidemiological survey in Italy

We tested 731 sera from apparently healthy light horses against Chlamydophila pneumoniae, by a microimmuno-fluorescence (MIF) test. To verify cross-reactions with other species of chlamvdiae, all sera with an antibody titre > or = 32 to C. pneumoniae were tested against both C. psittaci and C. abortus. Antibodies to C. pneumoniae were detected in 194 out of 731 (26.5%) samples tested, with antibody titres ranging from 32 to 1024. No antibody titre > or = 32 was detected in sera to C. abortus. Only few sera with a high antibody titre to C. pneumoniae reacted weakly with C. psittaci at the dilution of 1:32.     

聚羟基丁酸路径在克雷伯氏菌中的构建

以生物柴油的副产物甘油生产高附加值的1,3-丙二醇,现已成为提升生物柴油产业链经济性的重要途径,而中间代谢产物3-羟基丙醛积累造成细胞死亡,发酵异常终止是生物法生产1,3-丙二醇过程中的关键问题。不同于传统的降低3-羟基丙醛积累的思路,本文从增强克雷伯氏菌对3-羟基丙醛的抗逆性出发,改善克雷伯氏菌1,3-丙二醇的生产性能,首次将聚羟基丁酸路径引入克雷伯氏菌中,构建了新型基因工程菌,并对其1,3-丙二醇发酵性能及聚羟基丁酸代谢进行了初步的研究。经IPTG诱导,工程菌中检测到聚羟基丁酸,其含量随IPTG浓度增加而增大。优化的IPTG浓度为0.5 mmol/L。初始甘油50 g/L时,野生菌可正常发酵生产1,3-丙二醇,1,3-丙二醇浓度达到22.1 g/L,其质量得率为46.4%。当初始甘油达到70 g/L时,由于高浓度3-HPA积累,野生菌发酵终止,而工程菌可正常发酵生产1,3-丙二醇,PDO产量可达31.3 g/L,其质量得率为43.9%。同时检测到聚羟基丁酸积累。研究结果有助于加深对克雷伯氏菌1,3-丙二醇代谢机理的认识,为克雷伯氏菌的进一步优化提供了新的思路。     

氟喹诺酮类药物体外诱导肺炎克雷伯菌耐药后GyrA和ParC的变异

目的了解3种氟喹诺酮类（FQS）体外诱导肺炎克雷伯菌（Klebsiella pneumoniae,Kpn）耐药性的差异,研究肺炎克雷伯菌DNA旋转酶A亚单位（GyrA）和拓扑异构酶ⅣC亚基（ParC）的变异与其耐喹诺酮类药物的关系。方法采用环丙沙星（CW）、左氧氟沙星（LEX）和加替沙星（GAT）对从临床分离8株Kpn进行体外分步诱导,采用琼脂平板二倍稀释法测定CIP、LVF及GAT对Kpn诱导前、后的最低抑菌浓度（MIC）,并对诱导成功的17株Kpn的GyrA的基因（gyrA）和ParC的基因（parC）进行PCR扩增,选取其中8株KpnDNA测序并进行序列分析比较。结果8株耐FQS菌株都存在GyrA变异,同FQS耐药性相关的变异有Ser83（TCC）→Phe（TTC）、Ile（ATC）和Tyr（TAC）,Asp87（GAC）→Ala（GCC）、ma（GCC）和Glu（GAA）,5株Kpn同时存在ParC的变异：丝氨酸Ser80（AGC）→Ile（ATC）。结论本研究体外实验证实了Kpn可在长期低剂量的接触抗菌药物后形成耐药菌株。在高度耐FQS的Kpn中同时存在GyrA和ParC变异。     

乳及乳制品中肺炎克雷伯氏菌PCR-DHPLC检测新技术的建立

为了应用PCR结合变性高效液相色谱(DHPLC)技术建立乳品中肺炎克雷伯氏菌的快速检测方法,根据肺炎克雷伯氏菌16S-23S rRNA特异基因序列的特点设计特异性引物,PCR扩增的产物经DHPLC技术进行快速检测。以肺炎克雷伯氏菌等57株参考菌株做特异性试验;将肺炎克雷伯氏菌菌株稀释成不同梯度,做灵敏度试验。试验结果表明该方法具有很好的特异性,灵敏度较高,检测低限可达到100 CFU/mL,可以快速、准确检测肺炎克雷伯氏菌,是乳及乳制品中致病菌快速检测的新技术。     

肺炎克雷伯菌生物被膜的体外模型建立

目的研究临床分离的肺炎克雷伯菌在体外形成生物被膜的情况,为进一步研究生物被膜肺炎克雷伯菌的耐药机制奠定基础。方法采用改良平板法建立肺炎克雷伯菌生物被膜模型,用喷金法和扫描电镜观察鉴定,并对生物被膜的形成进行定量分析。结果23株临床分离的肺炎克雷伯菌菌株生物被膜形成能力不同,以强阳性生物被膜形成能力者为最多数。结论绝大多数临床分离的肺炎克雷伯菌菌株具有较强的生物被膜形成能力。应用改良平板法能够较好的在体外建立其生物被膜模型。     

Antibodies anti-Chlamydia pneumoniae and anti-Mycoplasma pneumoniae in patients with negative serology for hantavirus. Retrospective study.

The seroprevalence of Chlamydia pneumoniae and Mycoplasma pneumoniae in hantavirus seronegative patients, who had symptoms and signs compatible with pneumonia was established. For this purpose we used the indirect fluorescent antibody test. Titers > or = 1:16 for C. pneumoniae and M. pneumoniae were found in 8.6% and 17.1% of the serum, respectively, showing evidence of recent or current infection.     

Sequence divergence in the ORF6 gene of Mycoplasma pneumonia.

The ORF6 gene product of Mycoplasma pneumoniae is involved in a yet-unknown manner in the adhesion of the bacterium to its host cell. Part of the ORF6 gene is a repetitive DNA sequence (RepMP5), about 1,900 bp long. Seven additional similar copies of RepMP5 are dispersed on the genome. In the independently isolated strains M. pneumoniae M129 and FH, the RepMP5 copies residing in the ORF6 gene are not identical. Two conserved regions, ranging from nucleotides 1 to 799 and from nucleotide 1795 to the end of the gene, border a variable region, ranging from nucleotides 800 to 1794. This variable region differs in DNA sequence and by 201 bp. Analysis of RepMP5 copies outside the ORF6 gene showed that both M. pneumoniae M129 and M. pneumoniae FH carry a RepMP5 copy on a 6-kbp EcoRI fragment which has the same DNA sequence as the variable region of RepMP5 in the M. pneumoniae FH ORF6 gene. According to these data, a switch from the M. pneumoniae M129 ORF6 gene to the M. pneumoniae FH ORF6 gene could take place by gene conversion.