High frequency of Mycoplasma pneumoniae among patients with atypical pneumonia in Tehran, Iran

Identification of Mycoplasma pneumoniae-associated pneumonia cases among hospitalized patients using CLART® microarray technology

Objectives

Community-acquired pneumonia (CAP) is a global health condition that affects populations from all age groups. The laboratory identification of Mycoplasma pneumoniae as a causative agent of CAP is challenging because of its atypical and fastidious nature. Therefore, this study assessed the diagnostic potential of PneumoCLART bacteria® in identifying M. pneumoniae as a causative agent of pneumonia in hospitalized adults.

Methods

This prospective study used a cross-sectional approach to assess the diagnostic potential of PneumoCLART bacteria® for detecting M. pneumoniae in sputum samples procured from 27 patients with pneumonia who required hospitalization.

Results

The PneumoCLART bacteria® results illustrated that 7 of 27 patients with pneumonia were positive for M. pneumoniae (26%). However, the quality of sputum varied among the M. pneumoniae-positive and M. pneumoniae-negative samples. Fifty percent of the specimens obtained from patients positive for M. pneumoniae were saliva-contaminated and unsuitable for analysis.

Conclusions

Because the leukocyte count was low and sputum specimens were saliva-contaminated, these findings require further validation to prove the utility of CLART® microarray technology for the identification of M. pneumoniae in pneumonia-positive patients. Conclusively, this prospective study included a small number of clinical samples, which likely affected its outcomes.

Etiology and efficacy of anti-microbial treatment for community-acquired pneumonia in adults requiring hospital admission in Ukraine

BACKGROUND AND AIM

Empiric therapy of community-acquired pneumonia (CAP) remains the standard care and guidelines are mostly based on published data from the United States or Europe. In this study, we determined the bacterial etiology of CAP and evaluated the clinical outcomes under antimicrobial treatment of CAP in Ukraine.

METHODS

A total of 98 adult subjects with CAP and PORT risk II-IV were recruited for the study. The sputum diagnostic samples were obtained from all patients for causative pathogen identification. Subjects were randomly assigned in a 1:1 ratio to receive delafloxacin 300 mg (n=51) or moxifloxacin 400 mg (n=47) with blinding placebo. The switch to oral treatment was after a minimum of 6 IV doses according to clinical criteria. The total duration of antibacterial treatment was 5-10 days. In vitro susceptibility of pathogens to delafloxacin and other comparator antibiotics was determined.

RESULTS

The most frequently isolated pathogens in adults with CAP were S. pneumoniae - 19.5%, M. pneumoniae - 15.3%, H. influenzae - 13.2%, S. aureus - 10.5%, K. pneumoniae - 10.1%, and H. parainfluenzae - 6.4%. All isolates of S. pneumoniae, S. aureus, M. pneumoniae had sufficient susceptibility to appropriate antibiotics. 9.0% of H. influenzae strains were susceptible to azithromycin. 94.8 % of patients had a successful clinical response to delafloxacin at the end of treatment and 93.9 % - at test-of-cure.

CONCLUSIONS

In Ukraine, the major bacterial agents that induced CAP in adults were S. pneumoniae, M. pneumoniae, H. influenzae, S. aureus, K. pneumoniae, H. parainfluenzae, E. cloacae, L. pneumophila. Delafloxacin is a promising effective antibiotic for monotherapy for CAP in adults and could be used in cases of antimicrobial-resistant strains.

Frequency of Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia spp. among patients with atypical pneumonia in Tehran

Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia pneumoniae are the most common bacterial agents, which account for 15-40%, 2-15% and 5-10% of atypical community-acquired pneumonia (CAP) respectively. These agents are mostly associated with infection in the outpatient setting. The aim of this study was to evaluate the frequency of these pathogens among patients with CAP attending outpatient clinics in Tehran. A cross-sectional study was carried out of 150 patients attending to educational hospitals in Tehran with CAP. M. pneumoniae, L. pneumophila and Chlamydia spp. were detected by PCR assay, targeting the P1 adhesion gene, macrophage infectivity potentiator (mip) gene and 16S rRNA gene respectively from throat swabs obtained from each patient. A total of 86 (57.3%) of 150 patients were women; median age was 50 years (interquartile range, 35-65 years). M. pneumoniae, L. pneumophila and Chlamydia spp. were detected in 37 (24.7%), 25 (16.7%) and 11 (7.3%) patients respectively; of these, 66 patients (44%) were infected at least by one of these three pathogens. The frequency of L. pneumophila was significantly higher among patients over 60 years old (p 0.03). Coinfection was detected in seven patients (4.7%); six were infected by M. pneumoniae and L. pneumophila, and only one was infected by L. pneumophila and Chlamydia spp. M. pneumoniae was the most prevalent agent of atypical CAP, and L. pneumophila was more likely to infect elderly rather than younger people. Further studies on the prevalence of CAP and its aetiologic agents are needed to improve the diagnosis and treatment of CAP patients.

First Detection and Characterization of Macrolide-Resistant Mycoplasma pneumoniae from People with Community-Acquired Pneumonia in Iran

Objectives: Increasing macrolide resistance of Mycoplasma pneumoniae strains is becoming a public health concern worldwide. Nevertheless, no comprehensive genomic background of circulating isolates is available in our region. We aimed to study the genetic diversity of this microorganism using the multiple-locus variable-number tandem-repeat analysis method and to investigate the relationships between MLVA types and macrolide susceptibility profiles of the isolates. Materials and Methods: A total of 270 patients attending Tehran general university hospitals were included in this study. One throat swab was taken from each patient. M. pneumoniae was identified using culture and PCR assay. Macrolide resistance was determined using the broth microdilution method. The MLVA was performed by amplification of four variable-number tandem-repeat loci. Results: Of 270 specimens, M. pneumoniae was detected in 25.2% (n = 68) and 21.8% (n = 59) samples using PCR and culture, respectively. Approximately 56.9% of isolates were resistant to macrolides. Fifty-one of 59 M. pneumoniae isolates were divided into 6 distinct MLVA types. Conclusion: The macrolide-resistant M. pneumoniae (MRMP) rate in this study was relatively high and most of the MRMP isolates were assigned into the type 4/5/7/2. Since a significant association between MLVA type 4/5/7/2 and macrolide resistance of M. pneumoniae isolates was observed, further monitoring of genetic diversity of MRMP isolates might facilitate better understanding of epidemiology of this microorganism. Besides surveillance of the antibiotic susceptibility might be helpful to make necessary reconsiderations on guidelines for treatment of M. pneumoniae infection.

Epidemiology of Mycoplasma pneumoniae prevalence in Iranian patients: a systematic review and meta-analysis

Introduction. Mycoplasma pneumoniae is regarded as the important infectious agent of acute respiratory infections (ARIs) in the world. However, there is little knowledge about the prevalence of M. pneumoniae in Iran. Therefore, the aim of this study was to investigate the prevalence of M. pneumoniae in Iran through a meta-analysis of included studies.Methods. A systematic search was done by using electronic databases from papers that were published by Iranian authors to the end of February 2019. Then, 12 publications, which met our inclusion criteria, were enrolled for data extraction and analysis by using the 'metaprop program' in stata version 14.0.Results. The pooled prevalence of M. pneumoniae was 9 % (95 % confidence intervals: 5-16 %) ranging from 1 to 26 %. There was a significant heterogeneity among the 12 studies (X²=128.29; P<0.001; I ²=91.43 %). The funnel plot for publication bias showed no evidence of asymmetry.Conclusions. The frequency of M. pneumoniae in Iran is comparable with other parts of the world. Although the overall prevalence of M. pneumoniae was low, awareness about the distribution of these agent is very important because of higher infection rates in susceptible groups. In addition, these results showed the rates of M. pneumoniae had variation based on location, type of infection and sample, gender and detection rate and there was evidence of publication bias.

Rapid Detection of Mycoplasma pneumoniae by Loop-Mediated Isothermal Amplification (LAMP) in Clinical Respiratory Specimens

BACKGROUND

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) worldwide, especially among children and debilitated populations. The present study aimed to investigate a loop-mediated isothermal amplification (LAMP) technique for rapid detection of M. pneumoniae in clinical specimens collected from patients with pneumonia.

METHODS

Throat swabs were collected from 110 outpatients who suffered from pneumonia. Throat swab samples were obtained from patients referred to the hospital outpatient clinics of Tehran University hospitals, Iran in 2017. The presence of M. pneumoniae in the clinical specimens was evaluated by LAMP, PCR and culture methods. Sensitivity and specificity of the LAMP and PCR assays were also determined.

RESULTS

Out of 110 specimens, LAMP assay detected M. pneumoniae in 35 specimens. Detection limit of the LAMP assay was determined to be 33fg /μL or ∼ 40 genome copies/reaction. Moreover, no cross-reaction with genomic DNA from other bacteria was observed. Only 25 specimens were positive by the culture method. The congruence between LAMP assay and culture method was 'substantial' (ϰ=0.77). Specificity and sensitivity of LAMP assay were 88.2%, 100% in compare with culture. However, the congruence between LAMP assay and PCR assay was 'almost perfect' (ϰ=0.86). Specificity and sensitivity of LAMP assay were 92.5%, 100% in compare with PCR.

CONCLUSION

Overall, the LAMP assay is a rapid and cost-efficient laboratory test in comparison to other methods including PCR and culture. Therefore, the LAMP method can be applied in identification of M. pneumoniae isolates in respiratory specimens.

Polydatin suppresses the development of lung inflammation and fibrosis by inhibiting activation of the NACHT domain-, leucine-rich repeat-, and pyd-containing protein 3 inflammasome and the nuclear factor-κB pathway after Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) can infect both the upper and lower respiratory tracts. Polydatin (PD), a traditional Chinese medicine, is known to have anti-inflammation and antifibrosis properties. However, the protective effects of PD against MP pneumonia (MPP) remain unclear. So, the aim of this study was to describe the therapeutic effects and underlying mechanisms of PD against MPP. BALB/c mice were assigned to three groups: a normal control group, MP infection group, or PD-treated MP infection group. BEAS-2B cells transfected with or without NACHT domain-, leucine-rich repeat-, and pyd-containing protein 3 (NLRP3) were used to confirm the protective mechanisms of PD. Immunohistochemical analysis, Western blot analysis, enzyme-linked immunosorbent assay, and flow cytometry were used in this study. The results showed that PD treatment suppressed MP-induced lung injury in mice by suppressing the expression of inflammatory factors and inhibiting the development of pulmonary fibrosis. Meanwhile, PD treatment inhibited activation of the NLRP3 inflammasome and nuclear factor κB (NF-κB) pathway. Overexpression of NLRP3 reversed the protective effect of PD against MP-induced injury of BEAS-2B cells. Taken together, these results indicate that PD treatment suppressed the inflammatory response and the development of pulmonary fibrosis by inhibiting the NLRP3 inflammasome and NF-κB pathway after MP infection.