Effects of a combination of erythromycin sequential therapy and azithromycin on lung function and inflammatory factors in children with severe mycoplasma pneumonia

This study aimed to investigate the effect of erythromycin sequential therapy plus azithromycin on lung function and inflammatory factors in children with severe mycoplasma pneumonia (MP). Ninety-three severe MP children were selected and randomized into azithromycin group, erythromycin group, and combination group, 31 cases in each. The disappearance time of cough, fever, lung rale and X-ray shadow in the combination group were shorter than those in the azithromycin group and erythromycin group. The clinical treatment efficiency of the combination group was higher than that of the azithromycin group. After treatment, FVC, FEV1/FVC and PEF in combination group were higher than before treatment; IL-8, IL-6, CRP in combination group were lower than erythromycin group and azithromycin group. IL-8, IL-6, CRP are negatively correlated with disappearance time of cough, fever, pulmonary rale, X-ray shadow and clinical treatment efficiency; FEV1/FVC is positively correlated with disappearance time of cough and fever, pulmonary rales and X-ray shadow, and clinical treatment efficiency. Sequential erythromycin therapy combined with azithromycin in the treatment of MP can effectively inhibit high inflammatory reactions, control the disease in a timely manner, improve lung function and produce fewer adverse reactions.

Predicting Mycoplasma pneumoniae and Chlamydophila pneumoniae in community-acquired pneumonia (CAP) pneumonia: epidemiological study of respiratory tract infection using multiplex PCR assays

Community-acquired pneumonia (CAP) is a common illness that can lead to mortality. β-lactams are ineffective against atypical pathogen including Mycoplasma pneumoniae. We used molecular examinations to develop a decision tree to predict atypical pathogens with CAP and to examine the prevalence of macrolide resistance in Mycoplasma pneumoniae. We conducted a prospective observational study of patients aged ≥ 18 years who had fever and respiratory symptoms and were diagnosed with CAP in one of two community hospitals between December 2016 and October 2018. We assessed combinations of clinical variables that best predicted atypical pathogens with CAP by classification and regression tree (CART) analysis. Pneumonia was defined as respiratory symptoms and new infiltration recognized on chest X-ray or chest computed tomography. We analyzed 47 patients (21 females, 44.7%, mean age: 47.6 years). Atypical pathogens were detected in 15 patients (31.9%; 12 Mycoplasma pneumoniae, 3 Chlamydophila pneumoniae). Ten patients carried macrolide resistant Mycoplasma pneumoniae (macrolide resistant rate 83.3%). CART analysis suggested that factors associated with presence of atypical pathogens were absence of crackles, age < 45 years, and LD ≥ 183 U/L (sensitivity 86.7% [59.5, 98.3], specificity 96.9% [83.8, 99.9]). ur simple clinical decision rules can be used to identify primary care patients with CAP that are at risk for atypical pathogens. Further research is needed to validate its usefulness in various populations.Trial registration Clinical Trial (UMIN trial ID: UMIN000035346).

Effect of Qingfei Huatan Huoxue Decoction combined with azithromycin on pulmonary function and inflammatory factors in children with Mycoplasma pneumonia

To investigate the effect of Qingfei Huatan Huoxue Decoction combined with azithromycin on pulmonary function and inflammatory factors in children with Mycoplasma pneumonia. A total of 155 children with Mycoplasma pneumonia of toxic heat blocking lung syndrome were randomly divided into the control group (n=77) and the observation group (n=78) from March 2020 to March 2021. Both groups of children were given conventional treatment and azithromycin intravenous drip and the observation group was additionally given oral administration of Qingfei Huatan Huoxue Decoction, with 7 days as a course of treatment totaling 2 courses. The lung function, inflammatory factor level, immune function and coagulation function were compared between the two groups before and after treatment. After treatment, the symptom integral of fever, cough and pulmonary wet rales in the two groups were reduced, while FEV1, PEF and FEV1/ FVC were significantly increased, serum TNF-α, IFN- γ and IL-6 were significantly reduced, the levels of Immunoglobulin M (IgM), IgG and IgA were significantly reduced and plasma PT and APTT were significantly reduced, with more significant changes observed in the observation group (all P<0.05). The disappearance time of fever, cough and pulmonary moist rales in the observation group was significantly shorter than that in the control group (P<0.05). The recovery rate of the observation group was significantly higher than that of the control group (P<0.05). Qingfei Huatan Huoxue Decoction combined.

Mycoplasma genitalium and M. pneumoniae Regulate a Distinct Set of Protein-Coding Genes in Epithelial Cells

Mycoplasma genitalium and M. pneumoniae are two significant mycoplasmas that infect the urogenital and respiratory tracts of humans. Despite distinct tissue tropisms, they both have similar pathogenic mechanisms and infect/invade epithelial cells in the respective regions and persist within these cells. However, the pathogenic mechanisms of these species in terms of bacterium-host interactions are poorly understood. To gain insights on this, we infected HeLa cells independently with M. genitalium and M. pneumoniae and assessed gene expression by whole transcriptome sequencing (RNA-seq) approach. The results revealed that HeLa cells respond to M. genitalium and M. pneumoniae differently by regulating various protein-coding genes. Though there is a significant overlap between the genes regulated by these species, many of the differentially expressed genes were specific to each species. KEGG pathway and signaling network analyses revealed that the genes specific to M. genitalium are more related to cellular processes. In contrast, the genes specific to M. pneumoniae infection are correlated with immune response and inflammation, possibly suggesting that M. pneumoniae has some inherent ability to modulate host immune pathways.

Respiratory Pathogen Detection in Children: Saliva as a Diagnostic Specimen

We compared pathogen detection between saliva, nasopharyngeal and oropharyngeal swabs in children with respiratory symptoms. The sensitivity in nasopharyngeal swabs was 93% (95% confidence interval [CI]: 78%-98%), in oropharyngeal swabs 79% (95% CI: 60%-90%), in saliva overall 76% (95% CI: 58%-88%) and in 18 saliva samples collected with drooling or sponges, 94% (95% CI: 74%-99%). Saliva could be a relevant specimen alternative.

Development of a scale for early prediction of refractory Mycoplasma pneumoniae pneumonia in hospitalized children

Now there is no clinical scale for early prediction of refractory Mycoplasma pneumoniae pneumonia (RMPP). The aim of this study is to identify indicators and develop an early predictive scale for RMPP in hospitalized children. First we conducted a retrospective cohort study of children with M. pneumoniae pneumonia admitted to Children's Hospital of Nanjing Medical University, China in 2016. Children were divided into two groups, according to whether their pneumonia were refractory and the results were used to develop an early predictive scale. Second we conducted a prospective study to validate the predictive scale for RMPP in children in 2018. 618 children were included in the retrospective study, of which 73 with RMPP. Six prognostic indicators were identified and included in the prognostic assessment scale. The sensitivity of the prognostic assessment scale was 74.0% (54/73), and the specificity was 88.3% (481/545) in the retrospective study. 944 children were included in the prospective cohort, including 92 with RMPP, the sensitivity of the prognostic assessment scale was 78.3% (72/92) and the specificity was 86.2% (734/852). The prognostic assessment scale for RMPP has high diagnostic accuracy and is suitable for use in standard clinical practice.

Evaluation on blood coagulation and C-reactive protein level among children with mycoplasma pneumoniae pneumonia by different chest imaging findings

Mycoplasma pneumoniae infection may induce a systemic hypercoagulable abnormality, like organ embolism and infarction. Indexes of blood coagulation and C-reactive protein (CRP) have been reported different between healthy people and mycoplasma pneumoniae pneumonia (MPP) patients, but this difference in MPP patients with different chest imaging findings has rarely been reported.We performed a retrospective study of 101 children with MPP and 119 controls, combined with radiological examination and blood tests, to compare the blood coagulation and CRP level among MPP children with different chest imaging findings.For the MPP children with different chest imaging findings, there were significant differences in CRP, fibrinogen (FIB) and D-dimer (D-D) levels among subgroups (P = .004, P = .008 and P < .001 respectively). The CRP level in group of interstitial pneumonia was significantly higher than that in groups of bronchopneumonia and hilar shadow thickening (P = .003 and P = .001 respectively). And the FIB and D-D values in group of lung consolidation were significantly higher than that in the other 3 groups (all P < .05). When compared with controls, the white blood cell, CRP, FIB, and D-D levels in MPP children were significantly higher, and the activated partial thromboplastin time and thrombin time levels were significantly lower (all P < .05).Our results showed that CRP level changed most significantly in group of interstitial pneumonia, whereas FIB, D-D levels changed most significantly in the lung consolidation group.

Proteomic and mechanistic study of Qingxuan Tongluo formula and curcumin in the treatment of Mycoplasma pneumoniae pneumonia

OBJECTIVE

Mycoplasma pneumoniae (MP) is the only pathogen in the Mycoplasma family that can cause respiratory symptoms, including acute upper respiratory tract infection and bronchitis, which are often attributed to Mycoplasma pneumoniae pneumonia (MPP). MPP is one of the diseases that commonly affects the pediatric respiratory system, but its pathogenesis is unclear. This study investigated the therapeutic effects and mechanisms of Qingxuan Tongluo formula and its main component, curcumin, on MPP.

METHODS

A mouse model of MPP was obtained by nasal drip of the MP strain. The effects of Qingxuan Tongluo formula and curcumin on the treatment of MPP were studied. The proteomic profiles of the alveolar lavage fluid of mice in the model group, Qingxuan Tongluo formula group and curcumin group were evaluated by LC-MS/MS. ELISA and immunohistochemistry were used to verify the possible presence of MP infection biomarkers and drug target proteins.

RESULTS

Compared with the mice in the model group, the MPP mice in the Qingxuan Tongluo formula group had significantly reduced fever and cough and prolonged the cough incubation period. Moreover, the pulmonary pathology of the MPP mice was significantly improved, and the lung histopathological score was decreased. After treatment with Qingxuan Tongluo formula and curcumin, the functional and pathway abnormalities caused by MP were mainly inhibited. Levels of HSP90AA1, GRP94, ENO1 and PLG expression were verified by ELISA and immunohistochemistry.

CONCLUSION

Qingxuan Tongluo formula significantly reduced fevers and cough and prolonged the cough incubation period of MPP mice. Qingxuan Tongluo formula and curcumin significantly improved the pathological changes in lung tissue caused by MP infection. Proteomics analyses indicated that Qingxuan Tongluo formula and curcumin may have therapeutic effects on MPP by regulating energy metabolism, relieving oxidative stress and activating the fibrinolytic system. ENO1 and PLG were found to be potential drug targets.

Significance changes in the levels of myocardial enzyme in the child patients with Mycoplasma Pneumoniae Pneumonia

Mycoplasma is a gram-negative with thin wall bacterium that in humans, Mycoplasma pneumoniae causes pneumonia. This experiment was designed to explore the changes of myocardial enzymes in the mycoplasma pneumoniae pneumonia (MPP) child patients, and analyze the clinical value of these changes, in combination with the relevant indicators, symptoms and signs, in the evaluation of the pneumonia mycoplasma infection. For this aim, a total of 120 child patients with MPP in the acute phase,120 child patients with MPP in the recovery phase and 120 healthy children were simultaneously enrolled into this study to detect the levels of aspartate aminotransferase (AST), creatine kinase (CK), Creatine Kinase Isoenzyme (CK-MB) and lactic dehydrogenase (LDH) in blood. Results showed that MPP patients in the acute phase had higher levels of LDH, CK, CK-MB, AST, PCt, CRP, MPV, PDW, PCt, percentage of neutrophils, WBC count in the peripheral blood and ESR than those of the patients in the recovery patients and healthy children, while the level of PLT was lower (all P&lt;0.05). In the acute phase, the level of CK-MB correlated to the fever, fever duration, extrapulmonary organ damage (except for the myocardial damage) and the antibody titer of MP (all P&lt;0.05). It was concluded that in the acute phase of MMP, the level of CK-MB could not only reflect the myocardial damage readily but also the infection of MP as well as the resultant inflammation and disease progression, which could effectively guide the diagnosis and treatment of MPP.

Etiological analysis of virus, mycoplasma pneumoniae and chlamydia pneumoniae in hospitalized children with acute respiratory infections in Huzhou

BACKGROUND

Acute respiratory infections are a common disease in children with high mortality and morbidity. Multiple pathogens can cause acute respiratory infections. A 2-year survey of hospitalized children was conducted to understand the epidemic situation, seasonal spread of pathogens and the improvement of clinical diagnosis, treatment and prevention of disease in Huzhou, China.

METHODS

From September 2017 to August 2019, 3121 nasopharyngeal swabs from hospitalized children with acute respiratory infections were collected, and real-time PCR was used to detect various pathogens. Then, pathogen profiles, frequency and seasonality were analyzed.

RESULTS

Of the 3121 specimens, 14.45% (451/3121) were positive for at least one pathogen. Of the single-pathogen infections, RSV (45.61%, 182/399) was the most frequent pathogen, followed by PIVs (14.79%, 59/399), ADV (14.54%, 58/399), MP (10.78%, 43/399), and IAV (5.26%, 21/399). Of the 52 coinfections, RSV + PIVs viruses were predominantly identified and accounted for 40.38% (21/52) of cases. RSV was the most frequent pathogen in all four groups. The highest positive rate of the pathogens occurred in the winter (21.26%), followed by autumn (14.98%), the summer (14.11%) and the spring (12.25%).

CONCLUSION

Viruses are the main pathogens in hospitalized children with acute respiratory infections in Huzhou city, Zhejiang Province, China. Among the pathogens, RSV had the highest detection rate, and MP is also a common pathogen among children with acute respiratory infections. This study provided a better understanding of the distribution of pathogens in children of different ages and seasons, which is conducive to the development of more reasonable treatment strategies and prevention and control measures.

Superoxide dismutase 3 as an inflammatory suppressor in A549 cells infected with Mycoplasma pneumoniae

Herein, we found that serum concentration of superoxide dismutase 3 (SOD3) was significantly reduced in children with mycoplasma pneumonia (MP) infection. To study the roles of SOD3 in inflammatory regulation of MP infection, human A549 type II alveolar epithelial cells were stimulated with 10⁷ CCU/ml of MP to build MP infection in vitro. Secretion of pro-inflammatory cytokine interleukin (IL)-8 and tumor necrosis factor (TNF)-α were measured via enzyme-linked immunosorbent assay (ELISA) to assess the inflammatory response of A549 cells. Levofloxacin (LVFX) was used as an anti-inflammatory drug while recombinant TNF-α was used as an inflammatory promotor in MP-infected cells. Transcriptional activity of nuclear factor (NF)-κB was assessed by detecting protein levels of nuclear NF-κB and cytoplasm NF-κB using Western blot analysis. Our data suggested that the expression of SOD3 mRNA and protein, as well as content of SOD3 in cultured supernatant, were time-dependently inhibited in MP-infected A549 cells. However, lentiviruses-mediated SOD3 overexpression alleviated inflammatory response of MP-infected A549 cells, and prevented the unclear translocation of NF-κB, as evidenced by obviously reducing the production of IL-8 and TNF-α in cell cultured supernatant, as well as decreasing nuclear NF-κB while increasing cytoplasm NF-κB. Inspiringly, SOD3 overexpression induced anti-inflammatory effect and the inactivation of NF-κB was similar to that of 2 lg/ml of LVFX, but reversed by additional TNF-α treatment. Therefore, we can conclude that transcriptional activity of NF-jB was the underlying mechanism, by which SOD3 regulated inflammatory response in MP infection in vitro.

The Immunopathologic Effects of Mycoplasma pneumoniae and Community-acquired Respiratory Distress Syndrome Toxin. A Primate Model

Mycoplasma pneumoniae infection has been linked to poor asthma outcomes. M. pneumoniae produces an ADP-ribosylating and vacuolating toxin called community-acquired respiratory distress syndrome (CARDS) toxin that has a major role in inflammation and airway dysfunction. The objective was to evaluate the immunopathological effects in primates exposed to M. pneumoniae or CARDS toxin. A total of 13 baboons were exposed to M. pneumoniae or CARDS toxin. At Days 7 and 14, BAL fluid was collected and analyzed for cell count, percent of each type of cell, CARDS toxin by PCR, CARDS toxin by antigen capture, eosinophilic cationic protein, and cytokine profiles. Serum IgM, IgG, and IgE responses to CARDS toxin were measured. All animals had a necropsy for analysis of the histopathological changes on lungs. No animal developed signs of infection. The serological responses to CARDS toxin were variable. At Day 14, four of seven animals exposed to M. pneumoniae and all four animals exposed to CARDS toxin developed histological "asthma-like" changes. T cell intracellular cytokine analysis revealed an increasing ratio of IL-4/IFN-γ over time. Both M. pneumoniae and CARDS toxin exposure resulted in similar histopathological pulmonary changes, suggesting that CARDS toxin plays a major role in the inflammatory response.

[Effect of annexin A2 on EGFR/NF-κB signal transduction and mucin expression in human airway epithelial cells treated with Mycoplasma pneumoniae]

OBJECTIVE

To investigate the effect of annexin A2 (AnxA2) on epithelial growth factor receptor (EGFR)/nuclear factor-κB (NF-κB) signal transduction and mucin expression in human airway epithelial H292 cells treated with Mycoplasma pneumoniae (MP).

METHODS

H292 cells were divided into control group, MP group, NC-siRNA+MP group, and AnxA2 siRNA+MP group. The cells in the MP group were incubated with 5 μg/mL MP antigen for 2 hours. The cells in the NC-siRNA+MP and AnxA2 siRNA+MP groups were transfected with NC-siRNA and AnxA2 siRNA for 24 hours, followed by MP antigen stimulation for 2 hours. The MTT method was used to measure cell viability; quantitative real-time PCR was used to measure the mRNA expression of AnxA2; Western blot was used to measure the protein expression of AnxA2, phosphorylated EGFR (p-EGFR), and phosphorylated p65 NF-κB (p-p65 NF-κB); ELISA was used to measure the secretion of mucin 5AC (MUC5AC) and mucin 5B (MUC5B).

RESULTS

The MP and NC-siRNA+MP groups had lower cell viability than the control group (P<0.05). The AnxA2 siRNA+MP group had higher cell viability than the MP and NC-siRNA+MP groups and lower cell viability than the control group (P<0.05). The MP and NC-siRNA+MP groups had significantly higher mRNA and protein expression of AnxA2 than the AnxA2 siRNA+MP group (P<0.05). Compared with the control group, the MP and NC-siRNA+MP groups had significant increases in the protein expression of p-EGFR, p-p65 NF-κB, MUC5AC, and MUC5B (P<0.05); the AnxA2 siRNA+MP group had lower protein expression than the MP and NC-siRNA+MP groups, but higher protein expression than the control group (P<0.05).

CONCLUSIONS

AnxA2 is involved in the airway lesion induced by MP antigen via mediating EGFR/NF-κB signaling activation and mucin expression in human airway epithelial cells.

High Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in Children with Acute Respiratory Infections from Lima, Peru

BACKGROUND

Mycoplasma pneumoniae and Chlamydia pneumoniae are atypical pathogens responsible for pneumonia and a leading cause of morbidity and mortality in low income countries. The study objective is to determine the prevalence of this pathogens in Peruvian children with acute respiratory infections.

METHODS

A consecutive cross-sectional study was conducted in Lima, Peru from May 2009 to September 2010. A total of 675 children admitted with clinical diagnoses of acute respiratory infections were tested for Mycoplasma pneumoniae and Chlamydia pneumoniae detection by polymerase chain reaction (PCR), and clinical symptoms were registered by the attending physician.

RESULTS

Mycoplasma pneumonia was detected in 25.19% (170/675) of nasopharyngeal samples and Chlamydia pneumonia in 10.52% (71/675). The most common symptoms in patients with these atypical pathogens were rhinorrhea, cough and fever. A higher prevalence of Mycoplasma pneumoniae cases were registered in summer, between December 2009 and March 2010.

CONCLUSIONS

Mycoplasma pneumoniae and Chlamydia pneumonia are a significant cause of morbidity in Peruvian children with acute respiratory infections (ARI). Further studies should evaluate the use of reliable techniques such as PCR in Peru in order to avoid underdiagnoses of these atypical pathogens.

The effect of Platycodin D on the expression of cytoadherence proteins P1 and P30 in Mycoplasma pneumoniae models

Platycodin D is one of the most important monomers of the Qinbaiqingfei pellet (Qinbai), which has already been approved as the first effective new Traditional Chinese Medicine used to fight against Mycoplasma pneumoniae (M. pneumoniae) in clinic in China. In previous studies, pharmacodynamics experiment has proved that Platycodin D has anti-M. pneumoniae effect and the minimum inhibitory concentration (MIC) is 16mμg/ml. This paper further clarified that the mechanism underlying the anti-M. pneumoniae effect of Platycodin D might be due to M. pneumoniae adhesion proteins P1 and P30. P1 and P30 expression levels in M. pneumoniae strain, M. pneumoniae-infected BALB/c mice, and M. pneumoniae-infected A549 cells were determined by reverse transcription PCR. Platycodin D strongly inhibited P1 and P30 expression in M. pneumonia and high dosage of Platycodin D exhibited a greater effect on reducing P1 and P30 expression than low dose Platycodin D. Platycodin D prevented M. pneumoniae infection through inhibiting the expression of adhesion proteins, which might be one of the mechanisms for the anti-M. pneumoniae properties of Qinbai. These results provide a foundation to further explore the mechanisms of action of Qinbai in future studies.

The role of the PM2.5-associated metals in pathogenesis of child Mycoplasma Pneumoniae infections: a systematic review

The peak occurrence of Mycoplasma pneumoniae (M. pneumoniae) infections in childhood and haze episodes is concurrent. Together, the prevalence of macrolide-resistant M. pneumoniae varies among countries might also be related to the concentration of ambient fine particulate mass (aerodynamic diameter ≤2.5 μm, PM2.5). Numerous cohort studies have identified consistent associations between ambient PM2.5 and cardiorespiratory morbidity and mortality. PM2.5 is a carrier of the heavy metals. The relationship between PM2.5-associated metals and M. pneumoniae infections in childhood has been increasingly drawing public attention. First, we reviewed original articles and review papers in Pubmed and Web of Science regarding M. pneumoniae and PM2.5-associated metal and analyzed the structural basis of PM2.5-associated metal interaction with M. pneumoniae. Then, the possible mechanisms of action between them were conjectured. Mechanisms of oxidative stress induction and modulation of the host immune system and inflammatory responses via Toll-like receptors (TLRs) and/or the nuclear factor-kappa B (NF-κB) pathway are postulated to be the result of PM2.5-associated metal complex interaction with M. pneumoniae. In addition, a heavy metal effect on M. pneumoniae-expressed community-acquired respiratory distress syndrome (CARDS) toxin, and activation of the aryl hydrocarbon receptor (AhR) and TLRs to induce the differentiation of T helper (Th) cells are also regarded as important reasons for the influence of the heavy metals on the severity of M. pneumoniae pneumonia and the initial onset and exacerbation of M. pneumoniae associated asthma. PM2.5-associated metals via complex mechanisms can exert a great impact on the host through interaction with M. pneumoniae.

Role of the Mycoplasma pneumoniae/Interleukin-8/Neutrophil Axis in the Pathogenesis of Pneumonia

Neutrophil infiltration is the characteristic pathological feature of M. pneumoniae pneumonia (MPP). This study aimed to explore the associations among neutrophil activity, clinical presentation, and role of the M. pneumoniae/interleukin-8 (IL-8)/neutrophil axis in the pathogenesis of MPP. A total of 42 patients with MPP were prospectively enrolled in the study. Neutrophil activity, including matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO), and neutrophil elastase (NE), were measured. Clinical information was collected for all patients and control group. In vitro, IL-8 production was measured at different time points after M. pneumoniae infection of bronchial epithelial cells, and neutrophil activity was analyzed after IL-8 stimulation. The percentage of neutrophil in the bronchoalveolar lavage fluid was higher in the group of patients with high levels of M. pneumoniae DNA than in those with low levels of M. pneumoniae DNA (P < 0.05). IL-8, MMP-9, and NE in patients with MPP significantly increased compared with controls and decreased after treatment (P < 0.05). MPO and MMP-9 were associated with duration of fever (r = 0.332, P < 0.05) and length of stay (r = 0.342, P < 0.05), respectively. In vitro, M. pneumoniae induced IL-8 production by bronchial epithelial cells in a time dependent manner. MPO, MMP-9 and NE production by neutrophils significantly increased compared with medium controls after IL-8 stimulation. In summary, the M. pneumoniae/IL-8/neutrophil axis likely plays a vital role in the pathogenesis of MPP.

Rapid diagnosis of Mycoplasma pneumoniae in children with pneumonia by an immuno-chromatographic antigen assay

Mycoplasma pneumoniae is a particularly important pathogen that causes community acquired pneumonia in children. In this study, a rapid test was developed to diagnose M. pneumoniae by using a colloidal gold-based immuno-chromatographic assay which targets a region of the P1 gene. 302 specimens were analyzed by the colloidal gold assay in parallel with real-time PCR. Interestingly, the colloidal gold assay allowed M. pneumoniae identification, with a detection limit of 1 × 10(3) copies/ml. 76 samples were found to be positive in both real-time PCR and the colloidal gold assay; two specimens positive in real-time PCR were negative in the rapid colloidal gold assay. The specificity and sensitivity of the colloidal gold assay were 100% and 97.4%, respectively. These findings indicate that the newly developed immuno-chromatographic antigen assay is a rapid, sensitive and specific method for identifying M. pneumoniae, with potential clinical application in the early diagnosis of Mycoplasma pneumoniae infection.

Comparative "-omics" in Mycoplasma pneumoniae Clinical Isolates Reveals Key Virulence Factors

The human respiratory tract pathogen M. pneumoniae is one of the best characterized minimal bacterium. Until now, two main groups of clinical isolates of this bacterium have been described (types 1 and 2), differing in the sequence of the P1 adhesin gene. Here, we have sequenced the genomes of 23 clinical isolates of M. pneumoniae. Studying SNPs, non-synonymous mutations, indels and genome rearrangements of these 23 strains and 4 previously sequenced ones, has revealed new subclasses in the two main groups, some of them being associated with the country of isolation. Integrative analysis of in vitro gene essentiality and mutation rates enabled the identification of several putative virulence factors and antigenic proteins; revealing recombination machinery, glycerol metabolism and peroxide production as possible factors in the genetics and physiology of these pathogenic strains. Additionally, the transcriptomes and proteomes of two representative strains, one from each of the two main groups, have been characterized to evaluate the impact of mutations on RNA and proteins levels. This study has revealed that type 2 strains show higher expression levels of CARDS toxin, a protein recently shown to be one of the major factors of inflammation. Thus, we propose that type 2 strains could be more toxigenic than type 1 strains of M. pneumoniae.

SP-D, KL-6, and HTI-56 levels in children with mycoplasma pneumoniae pneumonia

The study was aimed to evaluate the potential biomarkers from pulmonary surfactant protein D (SP-D), Krebs von den Lungen-6 (KL-6), and 56-kD a human type I protein (HTI-56) in serum and bronchoalveolar lavage fluid samples of children with Mycoplasma pneumoniae pneumonia. This retrospective study, self-controlled study enrolled 34 Chinese children with M. pneumoniae pneumonia. The levels of SP-D, KL-6, and HTI-56 in bronchoalveolar lavage fluid samples were assessed and compared between patients with unilateral lung infection and contralateral lungs without any abnormal findings. Significant differences in the levels of SP-D, KL-6, and HTI-56 were observed in infected bronchoalveolar lavage fluid samples compared with uninfected samples (all P<0.05); however, there was no correlation between the serum level of SP-D, KL-6, and HTI-56 and their levels in infected and uninfected bronchoalveolar lavage fluid samples (P>0.05).

CONCLUSION

The high levels of SP-D, KL-6, and HTI-56 in infected bronchoalveolar lavage fluid samples may reflect the injury of alveolar epithelium caused by M. pneumoniae. Instead of SP-D in uninfected bronchoalveolar lavage fluid samples obtained by invasive bronchoscopy, serum SP-D may serve as a convenient medium to distinguish lung infection caused by M. pneumoniae.

Changes in levels of IL-9, IL-17, IFN-γ, dendritic cell numbers and TLR expression in peripheral blood in asthmatic children with Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) infection in children with asthma resulted in a more severe allergic state compared with a non-MP infected group. The infection rate of children with asthma was higher than that of the other groups, suggesting that being asthmatic may be a predisposing factor for MP infection and that the infection itself is an important co-factor in the disease progression of asthma. The number of dendritic cells (DCs) and the expression of TLR2 and TLR4 were compared in 22 asthmatic patients with MP infection, 22 asthmatic patients without MP infection, and 17 normal children as controls. The percentages of DCs in the peripheral blood of the three groups showed significant differences between asthmatic children with MP infection and controls, and asthmatic children without MP and controls (P<0.05), whereas no difference was found between asthmatic children with and without MP infection. The asthmatic children with MP infection group showed increased expression of TLR-2 and TLR-4 on DCs (P<0.01). Asthmatic patients infected with MP showed that DCs and TLRs (TLR-2, TLR-4) might play an important role in asthma pathogenesis with MP infection. The cytokines produced by the T-cell subsets in asthmatic children with MP infection showed a significant increase in IL-9 (P<0.01) and a decrease in IFN-γ (P<0.05) levels post-MP infection, while the IL-17 level remained stable (P>0.05), indicating a shift towards Th1/Th9 in the presence of MP infection.

Mycoplasma Pneumoniae and Chlamydophila pneumoniae in hospitalized children with bronchiolitis

Bronchiolitis is an acute lower respiratory tract infection in early childhood caused mainly by different viruses. Etiology of bronchiolitis have been studied in different environments and populations. Respiratory syncytial virus (RSV), human Metapneumovirus (hMPV), human Bocavirus (hBoV), human Rhinoviruses (hRV) have consistently been shown to predominate. Few studies however have attempted to determine whether other pathogens, particularly Mycoplasma Pneumoniae (MP) and Chlamydophila pneumoniae (CP), are associated with bronchiolitis in children under 2 years of age. The aim of this study was to determine the prevalence and clinical features of MP and CP in children under the age of 2 years presenting to the Iashvili Central Children Hospital in Tbilisi with various severities and clinical manifestations of bronchiolitis. Acute and convalescent serum samples were tested by ELISA for IgM and IgG antibodies to RSV, CP and MP.37 children under two years of age were studied. In 19 patients out of 37 (51.35%) etiological diagnosis were established and in 18 patients (48.65%) no pathogens were found. 11 patients (29.72%) had either CP or MP and 8 patients (21.62%) had RSV. Children infected with CP and MP had less severe bronchiolitis than those infected with RSV. Co-infection was not associated with disease severity. There were no statistically significant differences between groups with respect to length of hospital stay. Our study underlines the importance of atypical bacterial pathogens in acute bronchiolitis in children under 2 years and highlights the complex epidemiology and clinical features of these pathogens in this age group.

Surveillance of Mycoplasma pneumoniae infection among children in Beijing from 2007 to 2012

BACKGROUND

Mycoplasma pneumonia (M. pneumoniae) is one of the key pathogens of community-acquired pneumonia. A global pandemic of M. pneumoniae has occurred since 2010. The aim of this study was to survey the prevalence of M. pneumoniae in children in Beijing from 2007-2012.

METHODS

A total of 3 073 clinical specimens were obtained from pediatric patients with respiratory tract infections from January 2007 to December 2012, and examined by nested polymerase chain reaction. PCR products were visualized by 2% agarose gel electrophoresis, positive products sequenced, and compared with reference sequences in GenBank. Macrolide resistance-associated mutations were also detected for some positive samples.

RESULTS

Of the 3 073 specimens, 588 (19.13%) were positive for M. pneumoniae, 12.4% of which were accompanied by viral infections. Positive rates for M. pneumoniae were highest in 2007 and 2012, showing a significant difference when compared with other years. Infections tended to occur in autumn and winter and positive rates were significantly higher for children aged 3-16. The rate of macrolide resistance-associated mutations was 90.7%, and the predominant mutation was an A→G transition (89.92%) at position 2063 in domain V of the 23S rRNA gene.

CONCLUSIONS

M. pneumoniae outbreaks occurred in 2007 and 2012 in pediatric patients in Beijing, which is consistent with the global prevalence of M. pneumoniae. M. pneumoniae can cause multi-system infections in children, and may be accompanied with viral infections. We determined that school-age children are more susceptible to this disease, particularly in autumn and winter. Gene mutations associated with macrolide resistance were very common in M. pneumoniae-positive specimens during this period in Beijing.

Specific multilocus variable-number tandem-repeat analysis genotypes of Mycoplasma pneumoniae are associated with diseases severity and macrolide susceptibility

Clinical relevance of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) in patients with community-acquired pneumonia (CAP) by Mycoplasma pneumoniae (M. pneumoniae) is unknown. A multi-center, prospective study was conducted from November 2010 to April 2012. Nine hundred and fifty-four CAP patients were consecutively enrolled. M. pneumoniae clinical isolates were obtained from throat swabs. MLVA typing was applied to all isolates. Comparison of pneumonia severity index (PSI) and clinical features among patients infected with different MLVA types of M. pneumoniae were conducted. One hundred and thirty-six patients were positive with M. pneumoniae culture. The clinical isolates were clustered into 18 MLVA types. One hundred and fourteen (88.3%) isolates were resistant to macrolide, covering major MLVA types. The macrolide non-resistant rate of M. pneumoniae isolates with Mpn13-14-15-16 profile of 3-5-6-2 was significantly higher than that of other types (p≤0.001). Patients infected with types U (5-4-5-7-2) and J (3-4-5-7-2) had significantly higher PSI scores (p<0.001) and longer total duration of cough (p = 0.011). Therefore it seems that there is a correlation between certain MLVA types and clinical severity of disease and the presence of macrolide resistance.

More complications occur in macrolide-resistant than in macrolide-sensitive Mycoplasma pneumoniae pneumonia

We sought to understand the situation of macrolide-resistant genotypes of Mycoplasma pneumoniae, and analyze the relationship between macrolide-resistant genotypes and clinical manifestations of Mycoplasma pneumoniae pneumonia (MPP). Full-length sequencing of the 23S rRNA gene of M. pneumoniae was performed in 235 nasopharyngeal aspirates (NPAs) from children with MPP. We also retrospectively compared the clinical characteristics of macrolide-resistant (MR) M. pneumoniae infections and macrolide-sensitive (MS) M. pneumoniae infections. A total of 206 patients had point mutations in the M. pneumoniae 23S rRNA gene, and these patients are referred to as MR patients. The remaining 29 patients without point mutations are referred to as MS patients. Among 206 MR patients, 199 (96.6%) had A2063G mutations, 6 had A2063T mutations, and the remaining patients had an A2064G mutation. Among the clinical manifestations, we found that the median fever durations were 8 days (range, 0 to 42 days) and 6 days (0 to 14 days) (P < 0.01), the median hospitalization durations were 8 days (2 to 45 days) and 6 days (3 to 16 days) (P < 0.01), and the median fever durations after macrolide therapy were 5 days (0 to 42 days) and 3 days (0 to 10 days) (P < 0.01), respectively, in the MR and MS groups. We also found that the incidence of extrapulmonary complications in the MR group was significantly higher than that in the MS group (P < 0.05). Moreover, the radiological findings were more serious in the MR group than in the MS group (P < 0.05). The increasing prevalence of MR M. pneumoniae has become a significant clinical issue in the pediatric patients, which may lead to more extrapulmonary complications and severe clinical features and radiological manifestations.

AcuteChlamydia pneumoniaeandMycoplasma pneumoniaeInfections in Community-Acquired Pneumonia and Exacerbations of COPD or Asthma: Therapeutic Considerations

Rates of acute Chlamydia pneumoniae and Mycoplasma pneumoniae infections were determined in 115 adults hospitalized for community-acquired pneumonia (CAP), purulent exacerbations of COPD and acute exacerbations of bronchial asthma, by means of serology and molecular methods. Results were compared with those obtained in a matched control group. Common respiratory pathogens were isolated by cultures in 22.5% and 22.2% of CAP and exacerbated COPD patients, respectively. Cultures from exacerbated asthma patients were always negative. Serological and molecular evidence of current C. pneumoniae infection was obtained in 10.0%, 8.9% and 3.3% of CAP, COPD and asthma cases. The corresponding rates of acute M. pneumoniae infection were 17.5%, 6.7% and 3.3%, respectively. Finally, no difference was found between typical and atypical pathogen rates. These findings highlight the importance of taking into account C. pneumoniae and M. pneumoniae infections in guiding the choice of empirical antibacterial treatment for CAP and purulent exacerbations of COPD.

Carriage of Mycoplasma pneumoniae in the upper respiratory tract of symptomatic and asymptomatic children: an observational study

BACKGROUND

Mycoplasma pneumoniae is thought to be a common cause of respiratory tract infections (RTIs) in children. The diagnosis of M. pneumoniae RTIs currently relies on serological methods and/or the detection of bacterial DNA in the upper respiratory tract (URT). It is conceivable, however, that these diagnostic methods also yield positive results if M. pneumoniae is carried asymptomatically in the URT. Positive results from these tests may therefore not always be indicative of a symptomatic infection. The existence of asymptomatic carriage of M. pneumoniae has not been established. We hypothesized that asymptomatic carriage in children exists and investigated whether colonization and symptomatic infection could be differentiated by current diagnostic methods.

METHODS AND FINDINGS

This study was conducted at the Erasmus MC-Sophia Children's Hospital and the after-hours General Practitioners Cooperative in Rotterdam, The Netherlands. Asymptomatic children (n = 405) and children with RTI symptoms (n = 321) aged 3 mo to 16 y were enrolled in a cross-sectional study from July 1, 2008, to November 30, 2011. Clinical data, pharyngeal and nasopharyngeal specimens, and serum samples were collected. The primary objective was to differentiate between colonization and symptomatic infection with M. pneumoniae by current diagnostic methods, especially real-time PCR. M. pneumoniae DNA was detected in 21.2% (95% CI 17.2%-25.2%) of the asymptomatic children and in 16.2% (95% CI 12.2%-20.2%) of the symptomatic children (p = 0.11). Neither serology nor quantitative PCR nor culture differentiated asymptomatic carriage from infection. A total of 202 children were tested for the presence of other bacterial and viral pathogens. Two or more pathogens were found in 56% (63/112) of the asymptomatic children and in 55.5% (50/90) of the symptomatic children. Finally, longitudinal sampling showed persistence of M. pneumoniae in the URT for up to 4 mo. Fifteen of the 21 asymptomatic children with M. pneumoniae and 19 of the 22 symptomatic children with M. pneumoniae in this longitudinal follow-up tested negative after 1 mo.

CONCLUSIONS

Although our study has limitations, such as a single study site and limited sample size, our data indicate that the presence of M. pneumoniae in the URT is common in asymptomatic children. The current diagnostic tests for M. pneumoniae are unable to differentiate between asymptomatic carriage and symptomatic infection.

[Study of prevalence of rare and difficult to cultivate causative agents of inflammatory diseases of respiratory organs]

AIM

Study the prevalence of Mycoplasma pneumoniae, Chlamydophila pneumoniae, Chlamydophila psittaci, Legionella pneumophila, Moraxella catarrhalis, Cytomegalovirus, Herpes simplex I/II virus (HSV I/II) in individuals of various age groups with varying inflammatory broncho-pulmonary diseases.

MATERIALS AND METHODS

384 adults and 1001 children with clinically confirmed diagnoses were examined by PCR method: community-acquired pneumonia, acute bronchitis, bronchial asthma, ARD/ARVD, as well as 127 healthy children and 52 healthy adults. Sputum, smears from posterior fornix of pharynx, blood, saliva from children of the first year of life were used as material for the study.

RESULTS

Wide prevalence of M. pneumoniae and C. pneumoniae among adults and M. pneumoniae among children older than 1 year with inflammatory diseases of respiratory organs was established. C. psittaci, L. pneumophila, M. catarrhalis occurred in isolated cases in both adults and children. Active replication of herpes group viruses was detected in patients of all age groups with inflammatory broncho-pulmonary diseases, and in children Cytomegalovirus replication predominated, in adults--HSV I/II.

CONCLUSION

High frequency of prevalence of M. pneumoniae and C. pneumoniae in inflammatory diseases of respiratory tract was established, giving evidence of reasonability and necessity of examination of patients with various nosologic forms of diseases for these species of microorganisms with the aim of effective etiotropic therapy.

Guideline for the management of acute sore throat

The European Society for Clinical Microbiology and Infectious Diseases established the Sore Throat Guideline Group to write an updated guideline to diagnose and treat patients with acute sore throat. In diagnosis, Centor clinical scoring system or rapid antigen test can be helpful in targeting antibiotic use. The Centor scoring system can help to identify those patients who have higher likelihood of group A streptococcal infection. In patients with high likelihood of streptococcal infections (e.g. 3-4 Centor criteria) physicians can consider the use of rapid antigen test (RAT). If RAT is performed, throat culture is not necessary after a negative RAT for the diagnosis of group A streptococci. To treat sore throat, either ibuprofen or paracetamol are recommended for relief of acute sore throat symptoms. Zinc gluconate is not recommended to be used in sore throat. There is inconsistent evidence of herbal treatments and acupuncture as treatments for sore throat. Antibiotics should not be used in patients with less severe presentation of sore throat, e.g. 0-2 Centor criteria to relieve symptoms. Modest benefits of antibiotics, which have been observed in patients with 3-4 Centor criteria, have to be weighed against side effects, the effect of antibiotics on microbiota, increased antibacterial resistance, medicalisation and costs. The prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. If antibiotics are indicated, penicillin V, twice or three times daily for 10 days is recommended. At the present, there is no evidence enough that indicates shorter treatment length.

Mast cell TNF receptors regulate responses to Mycoplasma pneumoniae in surfactant protein A (SP-A)-/- mice

BACKGROUND

Mycoplasma pneumoniae (Mp) frequently colonizes the airways of patients with chronic asthma and likely contributes to asthma exacerbations. We previously reported that mice lacking surfactant protein A (SP-A) have increased airway hyperresponsiveness (AHR) during M pneumoniae infection versus wild-type mice mediated by TNF-α. Mast cells (MCs) have been implicated in AHR in asthma models and produce and respond to TNF-α.

OBJECTIVE

Determine the contribution of MC/TNF interactions to AHR in airways lacking functional SP-A during Mp infection.

METHODS

Bronchoalveolar lavage fluid was collected from healthy and asthmatic subjects to examine TNF-α levels and M pneumoniae positivity. To determine how SP-A interactions with MCs regulate airway homeostasis, we generated mice lacking both SP-A and MCs (SP-A(-/-)Kit(W-sh/W-sh)) and infected them with M pneumoniae.

RESULTS

Our findings indicate that high TNF-α levels correlate with M pneumoniae positivity in human asthmatic patients and that human SP-A inhibits M pneumoniae-stimulated transcription and release of TNF-α by MCs, implicating a protective role for SP-A. MC numbers increase in M pneumoniae-infected lungs, and airway reactivity is dramatically attenuated when MCs are absent. Using SP-A(-/-)Kit(W-sh/W-sh) mice engrafted with TNF-α(-/-) or TNF receptor (TNF-R)(-/-) MCs, we found that TNF-α activation of MCs through the TNF-R, but not MC-derived TNF-α, leads to augmented AHR during M pneumoniae infection when SP-A is absent. Additionally, M pneumoniae-infected SP-A(-/-)Kit(W-sh/W-sh) mice engrafted with TNF-α(-/-) or TNF-R(-/-) MCs have decreased mucus production compared with that seen in mice engrafted with wild-type MCs, whereas burden was unaffected.

CONCLUSION

Our data highlight a previously unappreciated but vital role for MCs as secondary responders to TNF-α during the host response to pathogen infection.

[Mycoplasma pneumoniae infections]

Mycoplasma pneumoniae causes respiratory infections, but in as many as one out of four of those having contracted the infection symptoms may appear elsewhere, sometimes without preceding respiratory symptoms. Among these, symptoms of central nervous system origin are most the common. Specific diagnosis of the infection is demanding, and is mainly based on serology. Application of nucleic acid detection tests might lead to an earlier diagnostics. Efforts associated with diagnosis should mainly be targeted at detecting epidemics as well as diagnosing patients with severe or abnormal symptoms during the epidemy.

[Clinical report on 68 cases of refractory mycoplasma pneumoniae pneumonia (RMPP)]

OBJECTIVE

To summarize the early diagnose and treatment approaches of Refractory Mycoplasma Pneumoniae Pneumonia (RMPP).

METHODS

Medical documents of 68 cases of RMPP were reviewed. Lab and radiology evident such as CBC, CRP, MP-IgM, X-ray, etc. were collected.

RESULTS

100% RMPP patients suffered from high fever. Positive sign of lung became clear with the development of the disease. Complications as impairment of liver function, cardiac function and rush developed in few patients. 2-4 rounds treatment of macrolides and Methyllprednisolone were necessary for RMPP while antibiotic may be considered when there were evidence of bacteria infection. Immunoglobulin was recommended to the patients when macrolides and steroid seemed ineffective. Bronchofibroscope played an active role regarding the diagnosis and treatment of RMPP.

CONCLUSION

Early diagnosis is crucial in RMPP. Combination of multitreatment approaches is the key to cure RMPP.

Atypical bacterial pathogen infection in children with acute bronchiolitis in northeast Thailand

BACKGROUND

Atypical bacterial pathogens--including Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Chlamydia trachomatis--are important infectious agents of the respiratory system. Most current information pertains to adults and little is known about the role of these organisms in lower respiratory tract infections among young children with acute bronchiolitis.

METHODS

This study detected these pathogens in the nasopharyngeal secretions of children between 1 month and 2 years of age admitted with acute bronchiolitis to hospitals in Khon Kaen, northeast Thailand. The M pneumoniae and C pneumoniae in the nasopharyngeal secretions were detected using multiplex and nested-polymerase chain reaction (PCR), whereas PCR and restriction fragment length polymorphism were used to investigate C trachomatis. These samples were also tested by multiplex reverse transcriptase PCR for respiratory viruses, including respiratory syncytial virus (RSV), influenza A, influenza B, and human metapneumovirus.

RESULTS

Of the 170 samples taken from hospitalized children with acute bronchiolitis, 12.9% were infected with atypical bacteria and 85.3% with respiratory viruses. RSV was the most common causative viral agents found in 64.7% of the samples. M pneumoniae was the most common atypical bacterial pathogen (14/170, 8.2%) and most of the patients infected with it were between 6 and less than 12 months of age (71 cases). Of the infected cases in this age group, 7 of 14 were infected with M pneumoniae and 4 of 4 with C pneumoniae. Both M pneumoniae (13/14) and C pneumoniae (4/4) had etiologies indicating viral coinfections. Four (2.4%) of all of the cases had C trachomatis infections and all of these were infected with RSV, including three patients less than 6 months of age.

CONCLUSION

These results suggest that in children with virus-induced acute bronchiolitis coinfection with M pneumoniae, C pneumoniae, or C trachomatis can be expressed differently in each age group. These atypical bacteria may be the important infectious agents that induce severe illness of acute bronchiolitis.

[Role of Chlamydia pneumoniae and Mycoplasma pneumoniae infections in the course of asthma]

Respiratory infections are one of the major causes of asthma exacerbations. Among numerous pathogens that may lead to exacerbations, particular attention should be paid to atypical bacteria: Chlamydia pneumoniae and Mycoplasma pneumoniae. Despite significant frequency, infections caused by these species are underestimated due to untypical clinical course and lack of easily accessible diagnostic tests. Although acute infection can be easily linked with deterioration of asthma control, the role of respiratory colonisation by Chlamydia pneumoniae or Mycoplasma pneumoniae has not been precisely defined. It is known that serologic signs of both past infection and chronic current infection (IgA) with Chlamydia pneumoniae or Mycoplasma pneumoniae are found more often in asthmatics compared to healthy controls. Besides respiratory colonisation by Chlamydia pneumoniae or Mycoplasma pneumoniae confirmed by culture or molecular tests is also more common in asthmatics. This is particularly relevant in cases of uncontrolled asthma that followed symptoms of respiratory infection. This may lead to the conclusion that atypical infections can play a role in asthma induction in previously healthy individuals as well as deteriorations in the course of the disease. Studies mentioned above have led to the new therapeutic possibility - eradication of Chlamydia pneumoniae. In some of the studies on eradication with macrolides promising results have been gained in terms of asthma control, but in most of the cases improvement was only temporary.

Etiological agents of community-acquired pneumonia in adult patients in Turkey; a multicentric, cross-sectional study

This cross-sectional study was intended to investigate the etiology of community-acquired pneumonia (CAP) in adult patients receiving no prior antibiotic therapy. Etiological agents were identified in 137 (62.8%) of 218 patients, the most frequent being Streptococcus pneumoniae (14.7%), Mycoplasma pneumoniae (13.8%) and respiratory syncytial virus (10.1%). A single pathogen was detected in 50.9% of cases and mixed pathogens in 11.9%. Typical pathogens were determined in 35.8% of cases, atypical pathogens in 20.2% and viral pathogens in 20.6%. Chronic obstructive pulmonary disease was a common (42.7%) comorbidity. S. pneumoniae was the most common pathogen in adult patients with CAP. Atypical pathogens were more common in patients < 65 years old, M. pneumoniae being the most common in this age group. Our results suggest that initial empiric antibiotic treatment in patients with CAP should cover S. pneumoniae and M. pneumoniae in Turkey.

A case of acute hepatitis with Mycoplasma pneumoniae infection and transient depression of multiple coagulation factors

We report a case of acute severe hepatitis with Mycoplasma pneumoniae (M. pneumoniae) infection and transient depression of multiple coagulation factors. A 5-year-old boy, previously healthy, was admitted with pneumonia. M. pneumoniae infection was confirmed by serology testing. Liver enzymes were elevated on admission without any past medical history. After treatment with azithromycin for 3 days, pneumonia improved, but the hepatitis was acutely aggravated. Partial thromboplastin time (PTT) was prolonged and depression of multiple coagulation factors developed. Liver biopsy revealed features consistent with acute hepatitis. A week later, liver enzymes were nearly normalized spontaneously. Normalization of prolonged PTT and coagulation factors were also observed several months later. This may be the first case of transient depression of multiple coagulation factors associated with M. pneumoniae infection.

Comparison of PCR, culture & serological tests for the diagnosis of Mycoplasma pneumoniae in community-acquired lower respiratory tract infections in children

BACKGROUND & OBJECTIVE

Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections in children. A specific diagnosis is important to institute the appropriate treatment. Information on diagnostic methods used for M. pneumoniae in Indian paediatric population is scarce. The study was thus conducted to compare polymerase chain reaction (PCR), culture and serology for the diagnosis of M. pneumoniae in community-acquired lower respiratory tract infections in children.

METHODS

Seventy five children aged 6 months to 12 yr with signs of community-acquired lower respiratory tract infections were selected for the study. Culture of nasopharyngeal aspirates was done. The serum samples were analyzed for the detection of IgM and IgG antibodies to M. pneumoniae. A 543 base pairs (bp) region of P1 gene of M. pneumoniae was selected for amplification in PCR assay applied to nasopharyngeal aspirates.

RESULTS

M. pneumoniae was isolated in culture from 4 (5.33%) children. Serological evidence of M. pneumoniae infection was observed in 16(21.3%) children. All culture positive patients were also positive by serology. Overall, PCR for M. pneumoniae was positive in 13 (17.3%) patients. All four culture positive patients were also positive by PCR. In 11 out of 13 (84.62%) PCR positive patients, serological evidence was there. Culture and/or serology and/or PCR positive results diagnosed M. pneumoniae infection in 18 (24%) of 75 patients.

INTERPRETATION & CONCLUSION

A combination of culture, serology and PCR may provide diagnostic information on the aetiology of M. pneumoniae community-acquired lower respiratory tract infections in paediatric population.

Clinical features of severe Mycoplasma pneumoniae pneumonia in adults admitted to an intensive care unit

Community-acquired pneumonia (CAP) due to Mycoplasma pneumoniae is usually mild, but some cases develop a severe life-threatening pneumonia. To investigate the clinical features of severe M. pneumoniae pneumonia in adults admitted to an intensive care unit, a multi-centre CAP surveillance study was performed. Among all hospitalized CAP cases between January 2000 and December 2004, there were 227 cases with M. pneumoniae pneumonia without the complication of other pathogens. A total of 13 of the cases required admission to an intensive care unit because of acute respiratory failure (ARF), and the remaining 214 cases (non-ARF) were low to moderately severe. The clinical features of ARF cases were compared with those of non-ARF cases. The underlying conditions in both types of case were identical, whereas clinical findings on admission clearly differed between the two groups. A regimen of an antibiotic effective against M. pneumoniae was begun on average at 9.3 days after the onset of symptoms in ARF cases, which was significantly later than for non-ARF cases (P<0.0001). However, two of the ARF cases progressed to respiratory failure despite the fact that adequate antibiotics were initially administered within 3 days after the onset of symptoms. All ARF cases received corticosteroids with adequate antibiotics, and their condition improved promptly. These results indicate that the clinical features, excluding underlying conditions, clearly differed between severe M. pneumoniae pneumonia and low to moderately severe pneumonia. The delayed administration of adequate antibiotics may contribute to the severity of M. pneumoniae pneumonia. Early corticosteroid therapy with adequate antibiotics should be considered.

Frequency of Chlamydia pneumoniae and Mycoplasma pneumoniae infections in children

OBJECTIVE

Chlamydia pneumoniae and Mycoplasma pneumoniae are among the most important pathogens of acute respiratory infections in children between the ages of 5 and 15 years. We aimed to investigate seasonal frequency of respiratory infections caused by C. pneumoniae and M. pneumoniae, frequency of coinfection, clinical findings and to determine relationship between clinical findings and laboratory results.

MATERIAL AND METHODS

Total of 284 patients (ranging 5-15 years of age), admitted to out-patient clinic with symptoms of respiratory tract infections between January 2004 and June 2005, were enrolled in the study. IgA, IgG and IgM antibodies against C. pneumoniae were quantitatively detected in all serum samples by using microimmunofluorescence (MIF). For the M. pneumoniae infection an IgM titer in the ELISA test were analyzed. Nasopharyngeal smear samples were collected for PCR detection.

RESULTS

Mean age was 8 +/- 2.2 (range 5-14) years. Mycoplasma pneumoniae IgM in 86 (30.2%) cases, C. pneumoniae IgM in one (0.3%) case, IgA in six (2.1%) cases and IgG in 10 (3.5%) cases were found positive. In 10 (3.5%) cases, both C. pneumoniae IgG (a titer of >1/216) and M. pneumoniae IgM were found positive concomitantly. The M. pneumoniae IgM in winter was found significantly higher compared to other seasons. Mycoplasma pneumoniae PCR method was performed on a total of 203 samples in 33 (16.2%) of which M. pneumoniae was found positive. The false positive ratio of PCR technique was found 16.2%. In a total of 217 examined samples by PCR method, the DNA of C. pneumoniae was found positive in two patients.

CONCLUSION

Mycoplasma pneumoniae was a common pathogen in respiratory infections. The otherwise C. pneumoniae infections were rarely seen in children. A Comparison of serology diagnostic tests for M. pneumoniae infections was found more sensitive and specific than PCR.