Diagnosis of Mycoplasma pneumoniae infection in autopsy and open-lung biopsy tissues by nested PCR

Allele-specific real-time PCR testing for minor macrolide-resistant Mycoplasma Pneumoniae

Background

The point mutations in 23S rRNA gene of Mycoplasma pneumoniae (M. pneumoniae) can lead to high-level resistance to macrolides. This study aimed to evaluate allele-specific real-time PCR (ASPCR) to detect the resistance-related mutations located at positions A2063G and A2064G of 23S rRNA gene.

Methods

We detected 178 pharyngeal swab specimens and calculated the proportions of resistant and sensitive quasispecies using ASPCR assays. ASPCR assays can detect down to 10 copies of 23S rRNA gene and achieved sensitivities of < 0.1% for A2063G and A2064G. We also compared the findings of ASPCR with the results of nested PCR with sequencing.

Results

Of 178 samples, 164 were found to have M. pneumoniae including 90.85% (149/164) samples with macrolide-resistant M. pneumoniae (MRMP) quasispecies by ASPCR, while 153 were found to be M. pneumoniae-positive including 71.90% (110/153) samples with MRMP quasispecies by nested PCR with sequencing. Of the 164 M. pneumoniae-positive samples, 61.59% (101/164) had the mixed population of wild-type and mutant M. pneumoniae, and 56.44% (57/101) of the latter contained the mutations at low frequency (≤50%).

Conclusion

ASPCR indicated that sensitive and resistant quasispecies coexisted in most of the M. pneumoniae positive samples. The ASPCR was a highly sensitive, accurate and rapid method for detecting the macrolide resistance-associated mutations and it could provide earlier and more drug-resistant information for M. pneumoniae research and the clinical therapy.

[Acute disseminated encephalomyelitis due to Mycoplasma pneumoniae in a previously healthy boy]

We present here the case of a previously healthy 5 year-old boy hospitalized in an intensive care unit due to tonic-clonic seizures focused on the face and right side of the body, and axillary temperature of 37.4°C. Common bacterial and viral etiology was ruled out through studies of cerebrospinal fluid (CSF) samples. Mycoplasma pneumoniae was suspected by a positive immunofluorescence serum test for IgM class antibodies. Finally, with a brain biopsy, M. pneumoniae was confirmed by polymerase chain reaction (PCR) and acute disseminated encephalomyelitis by pathological anatomy. The patient was treated with clarithromycin and had an uneventful evolution. At least to our knowledge, this is the first case in which M. pneumoniae DNA was detected by PCR in a brain biopsy.

Macrolide-resistant Mycoplasma pneumoniae in adults in Zhejiang, China

Mycoplasma pneumoniae is a major pathogen causing community-acquired pneumoniae (CAP), which is generally treated with macrolides. In recent years, however, although macrolide-resistant M. pneumoniae has been reported frequently, particularly in China, very little is known about the prevalence of macrolide-resistant M. pneumoniae infection in adults. In this study, we survey the macrolide-resistant M. pneumoniae in adults in Zhejiang province and characterize the mechanisms of resistance to macrolide. Six hundred fifty throat swab samples were collected from adult patients with CAP from January 2012 to August 2014. These samples were assayed by nested PCR and then cultivated for M. pneumoniae. All isolates were sequenced to determine the mutation in domain V of the 23S rRNA gene. The activities of 10 antibiotics against macrolide-resistant M. pneumoniae isolates were also investigated in vitro. Moreover, restriction fragment length polymorphism (RFLP) analysis of the amplified P1 gene was used to type 50 resistant strains. One hundred percent (71/71) of M. pneumoniae strains isolated from adults with CAP were resistant to erythromycin (MIC=128 to >256 μg/ml), clarithromycin (MIC=128 to >256 μg/ml), and azithromycin (MIC=32 to >64 μg/ml). Furthermore, all macrolide-resistant M. pneumoniae strains identified had an A2063G mutation in domain V of the 23S rRNA gene. Forty-six resistant strains (92.0%) were classified into type I strain on the basis of P1 gene PCR-RFLP analysis. According to these findings, it is suggested that macrolide-resistant M. pneumoniae infection is very prevalence among adults in Zhejiang province. Thus, there is necessary to perform the epidemiological monitoring of macrolide-resistant M. pneumoniae in the future.

An outbreak of Mycoplasma pneumoniae caused by a macrolide-resistant isolate in a nursery school in China

Eighteen out of 45 children were reported to have a respiratory illness during an outbreak at a temporary dormitory in a nursery school in China in 2011. To study the outbreak and to determine the risk factors for infection, an epidemiological investigation was performed. A standardized questionnaire was completed for a total of 45 children with the help of their guardians and parents. In addition, acute- and convalescent-phase serum samples and throat swabs from the children were taken for laboratory diagnosis. The diagnosis of a Mycoplasma-like illness was based on the following clinical criteria. The criteria were onset of illness after 31 May 2011, characterized by a cough, fever(>37.5 °C), or at least 3 of the following symptoms: fever, sore throat, cough or expectoration, and runny or stuffy nose. PCR-restriction fragment length polymorphism (PCR-RFLP), determination of MICs, and sequencing were performed to determine the genotype, antibiotic resistance, and sequence polymorphisms of the isolated strains, respectively. The paired sera revealed that 15 patients were infected with Mycoplasma pneumoniae. Epidemiology confirmed that this was a point source outbreak, characterized by a short incubation period, a high secondary attack rate, and a long period of hospitalization. PCR-RFLP analysis revealed that the 12 isolated strains of M. pneumoniae shared the same subtype P1 gene, and 23S rRNA sequence analysis showed that these strains harbored two macrolide-resistant gene-related point mutations at position 2063 and 2617. In this outbreak, the major risk factor was the distance between the bed of the first patient and the beds of close contacts (beds less than three meters apart). The strains isolated in this study were found to harbor two point mutations conferring macrolide resistance, indicating the importance of pathogen and drug resistance surveillance systems.

Family and community concerns about post-mortem needle biopsies in a Muslim society

Background

Post-mortem needle biopsies have been used in resource-poor settings to determine cause of death and there is interest in using them in Bangladesh. However, we did not know how families and communities would perceive this procedure or how they would decide whether or not to consent to a post-mortem needle biopsy. The goal of this study was to better understand family and community concerns and decision-making about post-mortem needle biopsies in this low-income, predominantly Muslim country in order to design an informed consent process.

Methods

We conducted 16 group discussions with family members of persons who died during an outbreak of Nipah virus illness during 2004-2008 and 11 key informant interviews with their community and religious leaders. Qualitative researchers first described the post-mortem needle biopsy procedure and asked participants whether they would have agreed to this procedure during the outbreak. Researchers probed participants about the circumstances under which the procedure would be acceptable, if any, their concerns about the procedure, and how they would decide whether or not to consent to the procedure.

Results

Overall, most participants agreed that post-mortem needle biopsies would be acceptable in some situations, particularly if they benefitted society. This procedure was deemed more acceptable than full autopsy because it would not require major delays in burial or remove organs, and did not require cutting or stitching of the body. It could be performed before the ritual bathing of the body in either the community or hospital setting. However, before consent would be granted for such a procedure, the research team must gain the trust of the family and community which could be difficult. Although consent may only be provided by the guardians of the body, decisions about consent for the procedure would involve extended family and community and religious leaders.

Conclusions

The possible acceptability of this procedure during outbreaks represents an important opportunity to better characterize cause of death in Bangladesh which could lead to improved public health interventions to prevent these deaths. Obstacles for research teams will include engaging all major stakeholders in decision-making and quickly building a trusting relationship with the family and community, which will be difficult given the short window of time prior to the ritual bathing of the body.

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.

Development of a novel DNA microarray to detect bacterial pathogens in patients with chronic obstructive pulmonary disease (COPD)

A novel microarray was constructed with DNA PCR product probes targeting species specific functional genes of nine clinically significant respiratory pathogens, including the Gram-positive organisms (Streptococcus pneumoniae, Streptococcus pyogenes), the Gram-negative organisms (Chlamydia pneumoniae, Coxiella burnetii Haemophilus spp., Legionella pneumophila, Moraxella catarrhalis, and Pseudomonas aeruginosa), as well as the atypical bacterium, Mycoplasma pneumoniae. In a “proof-of-concept” evaluation of the developed microarray, the microarray was compared with real-time PCR from 14 sputum specimens from COPD patients. All of the samples positive for bacterial species in real-time PCR were also positive for the same bacterial species using the microarray. This study shows that a microarray using PCR probes is a potentially useful method to monitor the populations of bacteria in respiratory specimens and can be tailored to specific clinical needs such as respiratory infections of particular patient populations, including patients with cystic fibrosis and bronchiectasis.

Causes of death in hospitalized adults with a premortem diagnosis of tuberculosis: an autopsy study

OBJECTIVE

To ascertain the immediate and underlying causes of death in adults who died in hospital with a premortem diagnosis of tuberculosis.

DESIGN

Causes of death were assessed independently by internists and pathologists in 50 adults admitted to two Soweto hospitals who died 24 h or more after admission. Detailed record reviews and complete autopsies, including HIV tests when not performed premortem, were performed. In addition, a variety of postmortem microbiological tests were performed.

RESULTS

Forty-seven patients had HIV infection; all were antiretroviral naive. Their median age was 34.5 years, median CD4 cell count was 48 cells/microl and median length of hospitalization before death was 6 days. Autopsy confirmed the premortem diagnosis of tuberculosis in 37 HIV-infected patients (79%), whereas 10 (21%) did not demonstrate tuberculosis. Bronchopneumonia and cytomegalovirus pneumonitis were the leading pathologies in these 10 patients. In 47 HIV-infected cadavers immediate or contributory causes of death were: extensive pulmonary tuberculosis, 32 (68%); disseminated tuberculosis, 28 (60%); bacterial pneumonia, 13 (26%); cytomegalovirus pneumonitis in seven (15%); cytomegalovirus DNA was found in 31 (66%) and Pneumocystis pneumonia was found in five cadavers (11%). The lung, followed by lymph nodes, liver and kidney, were the commonest sites of tuberculosis. Mycobacterium tuberculosis was cultured from 19 spleens, one of which was multidrug resistant, and Salmonella spp. was cultured from 11 splenic specimens.

CONCLUSION

We demonstrated disseminated, extensive tuberculosis associated with advanced HIV disease. Severe bacterial infections, including salmonellosis, were the leading co-morbidity, suggesting that hospitalized HIV-infected adults in whom tuberculosis is suspected may benefit from broad-spectrum antibiotic therapy.

Mycoplasma pneumonia: clinical and radiographic features in 39 children

BACKGROUND

The purpose of the present paper was to evaluate the clinical and chest radiographic features of pediatric patients with serologically proven Mycoplasma pneumoniae pneumonia (mycoplasma pneumonia).

METHODS

The clinical records and chest radiographs of 39 consecutive patients (19 male, 20 female; age 3-13 years) with serologically positive IgG and IgM mycoplasma pneumonia were reviewed.

RESULTS

More than 90% of patients presented with fever and cough and 48% of patients had leukocyte count >10,000/mm(3). A C-reactive protein (CRP) level >0.375 mg/dL was noted in 28 patients (72%). Chest radiographs displayed four different patterns: (i) peribronchial and perivascular interstitial infiltrates (n= 19, 49%); (ii) airspace consolidations (n= 15, 38%); (iii) reticulonodular opacification (n= 3, 8%); and (iv) nodular or mass-like opacification (n= 2, 5%). Bilateral peribronchial perivascular interstitial infiltrations in central and middle lung zones were frequently seen (n= 19, 49%). Other radiological features were bilateral lesions in 51% of patients, pleural effusion in 23%, and hilar lymphadenopathy in 13%. Means of duration for treatment response and hospitalization were 2.5 and 5 days, respectively.

CONCLUSION

There are various radiological features of mycoplasma pneumonia in children. Bilateral peribronchial and perivascular interstitial infiltrates were most frequently seen in the present patients.

Mycoplasma pneumoniae pneumonia: differential diagnosis by computerized tomography

OBJECTIVE AND BACKGROUND

This study was designed to clarify chest computerized tomography (CT) findings of Mycoplasma pneumoniae pneumonia facilitating differential diagnosis from CAP (community acquired pneumonia) caused by other organisms.

METHODS

We retrospectively reviewed the CT findings of 36 patients (median age 33 years, 15 males, 21 females) with serologically proven M. pneumoniae pneumonia and 52 patients (median age 61 years, 37 males, 15 females) suffering from CAP with no serological evidence of M. pneumoniae infection. The CT images were analyzed by experienced pulmonologists.

RESULTS

The most common finding in the M. pneumoniae pneumonia group was bronchial wall thickening, when we compared it with the CAP group (p<0.0001, Fisher's exact probability test). In the CAP group infected with other organisms, dense consolidations with air bronchograms were more frequent than any other findings (p=0.0279, chi-square test).

CONCLUSIONS

The diagnosis of M. pneumoniae pneumonia would appear to be reliable when we found bronchial wall thickening in the chest CT images.

Mycoplasma pneumoniae detection with PCR in renal tissue of a patient with acute glomerulonephritis

Renal disease concurrent with a Mycoplasma pneumoniae infection is uncommon. In this report we describe the clinical outcome of a 6-year-old patient who presented with a rapidly progressive glomerulonephritis that required dialysis. A kidney biopsy was performed, and the results revealed membranoprolipherative glomerulonephritis. The IgM serology was positive, and M. pneumoniae DNA was detected in a renal biopsy sample using a nested-PCR assay. The outcome was good.

Infectious pulmonary complications after stem cell transplantation or chemotherapy: diagnostic yield of bronchoalveolar lavage

Hematologic patients are at high risk for infectious pulmonary complications after stem cell transplantation (SCT) or chemotherapy. The aim of this study was to detect the range of pulmonary pathogens in these patients, analyzing 95 bronchoalveolar lavage (BAL) samples with classic and molecular (polymerase chain reaction [PCR]) detection methods. Human cytomegalovirus (HCMV) was detected in 33, herpes simplex virus in 21, human herpesvirus 6 in 24, and other viruses in 16 samples. Aspergillus species were detected in 19, Candida species in 25, and Gram-positive bacteria in 29 samples. The additional use of PCR detection methods increased the diagnostic yield from 56% to 73%, especially concerning viral and fungal infections in BAL samples. No infectious agent was detected in 26 samples. Interestingly, a high incidence of polymicrobial infections (50/95) was detected, dominated by HCMV co-infections, especially after allogeneic SCT. Within 3 years of follow-up, a poor outcome of co-infections of Aspergillus species with HCMV in 9 of 10 cases could be documented, whereas only 7 of 20 patients died with noninfectious BAL results. Herpesviruses, fungi, and Gram-positive bacteria were detected most frequently, and in 53%, polymicrobial infections were diagnosed.

Single-run, parallel detection of DNA from three pneumonia-producing bacteria by real-time polymerase chain reaction

A molecular assay for parallel detection of three bacteria, Chlamydia (C.) pneumoniae, Legionella (L.) spp., and Mycoplasma (M.) pneumoniae, in clinical specimens by a set of real-time polymerase chain reactions (PCRs) in a single run was evaluated. Bacterial DNAs were extracted by an automated DNA extraction protocol on the MagNA Pure LC System. Amplification and detection were done by real-time PCR on the LightCycler (LC) instrument. For amplification, specific oligonucleotides derived from the 16s rRNA genes of C. pneumoniae, L. spp., and M. pneumoniae were used. The three assays were complemented with an internal control (IC), a specially designed DNA fragment which contains the specific primer binding sites for the three PCRs. The IC was added to the samples, co-extracted, and co-amplified. Primers and hybridization probes were designed to suit one LC PCR program. LC PCRs were established, detection limits were determined, and clinical samples were tested. The detection limits were found between 5.0 and 0.5 IFU/CFU per PCR reaction for each of the bacteria. A total number of 100 clinical specimens were tested for validation of the molecular assay. Tested samples included 63 bronchoalveolar lavages (BALs) and 37 induced sputa specimens. The internal control was detected in all negative and low-positive samples; no inhibition was found throughout the whole study. Additionally, samples underwent testing by culture for L. spp., and M. pneumoniae; for C. pneumoniae, the serological microimmunofluorescence (MIF) test was used. In conclusion, the developed set of LC PCR assays permits parallel detection of C. pneumoniae, L. spp., and M. pneumoniae in a single LC run. This molecular assay may lead to accurate and early diagnosis of pneumonia produced by these three types of bacteria. The assay proved to be suitable for the high-throughput routine diagnostic laboratory.

Mycoplasma pneumoniae and its role as a human pathogen

Mycoplasma pneumoniae is a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of morbidity associated with it in both children and adults. Serious infections requiring hospitalization, while rare, occur in both adults and children and may involve multiple organ systems. The severity of disease appears to be related to the degree to which the host immune response reacts to the infection. Extrapulmonary complications involving all of the major organ systems can occur in association with M. pneumoniae infection as a result of direct invasion and/or autoimmune response. The extrapulmonary manifestations are sometimes of greater severity and clinical importance than the primary respiratory infection. Evidence for this organism's contributory role in chronic lung conditions such as asthma is accumulating. Effective management of M. pneumoniae infections can usually be achieved with macrolides, tetracyclines, or fluoroquinolones. As more is learned about the pathogenesis and immune response elicited by M. pneumoniae, improvement in methods for diagnosis and prevention of disease due to this organism may occur.

Laboratory diagnosis of Mycoplasma pneumoniae infection

Diagnosis of Mycoplasma pneumoniae infection is challenging due to the fastidious nature of the pathogen, the considerable seroprevalence, and the possibility of transient asymptomatic carriage. During recent years, various new techniques have been adapted for the diagnosis of M. pneumoniae infection, notably in the field of molecular biology. Standard polymerase chain reaction (PCR) is currently the method of choice for direct pathogen detection, but several PCR-related methods provide enhanced sensitivity or more convenient handling procedures, and have been successfully applied for research purposes. Among these techniques are real-time PCR, nested PCR, reverse transcriptase PCR (RT-PCR) and multiplex PCR. Generally, amplification-based methods have replaced hybridization assays and direct antigen detection. Serology, which is the basic strategy for mycoplasma diagnosis in routine clinical practice, has been improved by the widespread availability of sensitive assays for separate detection of different antibody classes. For the diagnosis of mycoplasma pneumonia, serology and direct pathogen detection should be combined. Extrapulmonary diseases may be diagnosed by direct pathogen detection alone, but the value of this diagnostic approach is limited by the probably immunologically mediated pathogenesis of some manifestations. This review summarizes the current state of Mycoplasma pneumoniae diagnosis, with special reference to molecular techniques. The value of different methods for routine diagnosis and research purposes is discussed.

Rapid-cycle PCR for detection and typing of Mycoplasma pneumoniae in clinical specimens

We designed several new primers and modified previously described species- and type-specific primers targeting the Mycoplasma pneumoniae P1 adhesin gene. Optimized thermal profiles allowed one-step or nested PCR to be completed in less than 1 h. In 10 patients with pneumonia, M. pneumoniae type 1 was identified in 3 and type 2 in 7.

Mycoplasma pneumoniae pneumonia: radiographic and high-resolution CT features in 28 patients

OBJECTIVE

The aim of the study was to compare the radiographic and the high-resolution CT findings of Mycoplasma pneumoniae pneumonia.

MATERIALS AND METHODS

The chest radiographs and 1.5-mm collimation CT scans obtained in 28 patients with serologically proven M. pneumoniae pneumonia were retrospectively reviewed. The radiographs and CT scans were analyzed independently by two observers.

RESULTS

The most common finding on radiography was the presence of air-space opacification (n = 24), which was patchy and segmental (n = 9) or nonsegmental (n = 15) in distribution. On high-resolution CT, areas of ground-glass attenuation were seen in 24 patients (86%) and air-space consolidation in 22 (79%). In 13 patients (59%), the areas of consolidation had a lobular distribution evident on CT. Nodules were seen more commonly on high-resolution CT (25 of 28 patients, 89%) than on radiography (14 patients, 50%) (p < 0.01, chi-square test). In 24 (86%) of the 28 patients, the nodules had a predominantly centrilobular distribution on CT. Thickening of the bronchovascular bundles was identified more commonly on CT (23 of 28 patients, 82%) than on radiography (five patients, 18%) (p < 0.01, chi-square test).

CONCLUSION

The lobular distribution, centrilobular involvement, and interstitial abnormalities in M. pneumoniae pneumonia are often difficult to recognize on radiography but can usually be seen on high-resolution CT.

An outbreak of acute respiratory disease caused by Mycoplasma pneumoniae and adenovirus at a federal service training academy: new implications from an old scenario

Outbreaks of Mycoplasma pneumoniae and adenovirus have been reported in military institutions for several decades. During a recent outbreak in a federal service training academy, we performed an epidemiological and laboratory investigation to better characterize and control the outbreak. Of 586 students responding to a questionnaire, 317 (54%) reported having a respiratory illness during the outbreak period. Among 42 students who underwent complete laboratory testing, 24 (57%) had evidence of M. pneumoniae infection, 8 (19%) had evidence of adenovirus infection, and 4 (10%) had evidence of both. Polymerase chain reaction testing of oropharyngeal swabs revealed more acute M. pneumoniae infections (57% positive) than did serology or culture. Multivariate analysis revealed that visiting the campus health clinic >3 times for a nonrespiratory condition, such as injury, was a significant risk factor for illness among freshmen early in the course of the outbreak, whereas having an ill roommate was a risk factor throughout the duration of the outbreak.

Incidence of upper respiratory tract Mycoplasma pneumoniae infections among outpatients in Rhône-Alpes, France, during five successive winter periods

In this prospective study, nasal swab samples from patients with acute respiratory infections were evaluated for the presence of Mycoplasma pneumoniae. This PCR-plus-hybridization-based detection was associated with the detection of other viral agents. During the five winter surveillance periods, 3,897 samples were collected by 75 medical practitioners participating in the Groupe Régional d'Observation de la Grippe surveillance network in Rhône-Alpes (France). M. pneumoniae was detected in 283 samples (7.3%); its rate of detection ranged from 10.1 to 2.0% over the five periods, and it was the second most frequently isolated pathogen during the survey, after influenza A. Three high-prevalence winters were observed, yielding an early winter peak of M. pneumoniae infection which was observed in all age groups. No statistically significant difference was detected between rates of infections in the different age groups, but M. pneumoniae infection was significantly related to lower respiratory tract infection during periods of high prevalence. This study defined the frequency of M. pneumoniae detection from nasal swab specimens in patients with acute respiratory infections, confirming its high prevalence and the presence of large outbreaks due to this pathogen.