Analysis of mycoplasmal pleural effusion by the polymerase chain reaction

The clinical significance of and the factors associated with macrolide resistance and poor macrolide response in pediatric Mycoplasma pneumoniae infection: A retrospective study

BACKGROUND

Macrolide-resistant Mycoplasma pneumoniae (MRMP) infection is increasing worldwide. However, its clinical significance is still uncertain.

METHODS

The data of the Laboratory Medicine Department of Chang Gung Memorial Hospital in northern Taiwan was searched for children with molecular confirmed macrolide-susceptible Mycoplasma pneumoniae (MSMP) and MRMP infections between January 2011 and December 2018. The clinical features, laboratory data, and chest image presentations were compared between patients with MRMP and MSMP infections and between patients with good and poor macrolide response, respectively.

RESULTS

Records from 158 patients were recovered. Of the enrolled patients 34 (22%) suffered MRMP infection, 27 (17%) had pleural effusions, and 47 (32%) had poor macrolide response. The macrolide resistance rate was 12% in 2011, 20% between 2015 and 2016, and 50% between 2017 and 2018, respectively. Other than a poor macrolide response, the MRMP and MSMP infections are clinically indistinguishable. The presence of pleural effusion and MRMP infections were found to be independently associated with a poor macrolide response, with odds ratios (95% confidence interval) of 14.3 (4.9-42.0) and 14.6 (5.4-40), respectively. The macrolide resistance rate of the patients with a poor macrolide response was 49% and 18% among all the patients enrolled and the patients with a pleural effusion, respectively.

CONCLUSION

The macrolide resistance rate had possibly increased in recent years in Taiwan and should be continuously monitored. In addition, the macrolide response could be misleading in predicting a macrolide resistance especially for the patients with a pleural effusion.

Clinical Significance of Pleural Effusion in Mycoplasma pneumoniae Pneumonia in Children

The clinical significance of pleural effusion in Mycoplasma pneumoniae (MP) pneumonia in children has not yet been elucidated. Herein, we investigated the clinical implications of pleural effusion in children with MP pneumonia. Overall, 150 children with MP pneumonia transferred to a tertiary hospital were enrolled in this study. Information on their clinical, laboratory, and radiological features was retrospectively obtained from medical chart reviews. In total, 24 (16.0%) children had pleural effusion at the time of admission. The duration of fever and length of hospitalization were significantly longer in the pleural effusion group than in the non-pleural effusion group. A significantly higher proportion of individuals in the pleural effusion group had a poor response to stepwise treatment for MP pneumonia. The mean C-reactive protein, lactate dehydrogenase, and aspartate aminotransferase levels were significantly higher in the pleural effusion group than in the non-pleural effusion group at admission. The prevalence of severe pneumonia, defined on the basis of the extent of pneumonic lesions on chest radiography, was higher in the pleural effusion group than in the non-pleural effusion group. However, there was no significant intergroup difference in the proportion of macrolide-resistant MP cases or respiratory viral coinfections. The presence of pleural effusion in children with MP pneumonia indicated a more severe clinical course and poor treatment response. The results of the present study would help in the creation of a therapeutic plan and prediction of the clinical course of MP pneumonia in children.

Predictive Factors of the Responses to Treatment of Mycoplasma pneumoniae Pneumonia

The prevalence of refractory Mycoplasma pneumoniae (MP) pneumonia is increasing. The present study aimed to identify the predictive factors of responses to treatment of MP pneumonia in children. A total of 149 children were diagnosed with MP pneumonia, of whom 56 were included in the good response group, 75 children in the slow response group, and 18 children in no response or progression group. Data on the clinical, laboratory, and radiologic features were retrospectively obtained through medical chart reviews. The severity of pneumonia, based on the extent of pneumonic lesions on chest x-ray (adjusted odds ratio (aOR), 10.573; 95% confidence intervals (CIs), 2.303-48.543), and lactate dehydrogenase (LDH) levels (aOR, 1.002; 95% CIs, 1.000-1.004) at the time of admission were associated with slow response to treatment of MP pneumonia. Pleural effusion (aOR, 5.127; 95% CIs, 1.404-18.727), respiratory virus co-infection (aOR, 4.354; 95% CIs, 1.374-13.800), and higher LDH levels (aOR, 1.005; 95% CIs, 1.002-1.007) as well as MP-specific IgM titer (aOR, 1.309; 95% CIs, 1.095-1.564) were associated with no response or progression of MP pneumonia. The area under the curve for the prediction of no or poor response in MP pneumonia using pleural effusion, respiratory virus co-infection, LDH levels, and MP-specific IgM titer at the time of admission was 0.8547. This study identified the predictive factors of responses to treatment of MP pneumonia in children, which would be helpful in establishing a therapeutic plan and predicting the clinical course of MP pneumonia in children.

Impact of antibiotic therapy on laboratory analysis of parapneumonic pleural fluid in children

OBJECTIVE

The therapeutic management of parapneumonic pleural effusions (PPE) is controversial in children. Decision-making often relies on parameters such as gross appearance of pleural fluid and on bacteriologic and biochemical analyses. Our goal was to describe the laboratory profile of PPE in children and to assess the influence of previous administration of antibacterial agents on culture and biochemical results.

PATIENTS AND METHODS

This was a prospective study including children (age, 1 month to 16 years) with a diagnosis of PPE. Two groups were evaluated: children with or without antibiotic treatment up to 48 hours before analysis of pleural fluid. Results were analyzed using the χ(2) or Mann-Whitney test (α = .05). Odds ratio and 95% confidence intervals (95% CIs) were calculated, with control of previous antibiotic therapy using multivariate logistic regression analysis, to determine the risk of empyema associated with specific biochemical parameters.

RESULTS

One hundred ten children were selected. Fifty percent had received antibiotics at least 48 hours before pleural fluid analysis. Differences were observed between the groups in terms of PPE gross appearance (P = .033) and identification of bacteriologic agent by culture or Gram stain (P = .023). Biochemical parameters (pH ≤7.1 and glucose ≤40 mg/dL) were associated with increased odds of receiving a more invasive treatment. For pH, the odds ratio was 9.614 (95% CI, 1.952-47.362; P = .005); and for glucose, 9.201 (95% CI, 1.333-63.496; P = .024).

CONCLUSIONS

Previous use of antibacterial agents affected the bacteriologic analysis of pleural fluid in this pediatric sample admitted for PPE. However, it did not interfere significantly with biochemical parameters of pleural fluid.

Massive empyema caused by Mycoplasma pneumoniae in an adult: a case report

Background

Mycoplasma pneumoniae is responsible for more than 20% of community acquired pneumonia cases, and capable of causing upper respiratory illness as well. Complications of M.pneumoniae infections include CNS involvement but other as pericarditis were also reported. The lack of feasible culture methods and under appreciation of the pathogens ability to cause invasive disease leads to reduced number of diagnosed M.pneumoniae related complications. In contrast to many other respiratory pathogens causing pneumonia, M. pneumoniae related severe pleural complications were almost never reported.

Case presentation

We report a previously healthy 57 years old woman presented with indolent massive right pleural effusion, leukocytosis and elevated ESR. Extensive microbiological evaluation didn't reveal any pathogen in the pus even before antibiotic treatment was started. Surprisingly, M.pneumoniae DNA was detected in the pus from the empyema using PCR designed to detect M.pneumoniae. A serological assay (Serodia-Myco II) using convalescent serum was indeterminate with a titer of 1:80. The patient responded well to a treatment that included right thoracotomy with pleural decortication and a combination of antibiotics and anti-inflammatory medications.

Conclusion

M.pneumoniae related empyema was never reported before in adult patients and was reported in only a few pediatric patients. In our patient there was no evidence to any common pathogens even before initiating antibiotic treatment. The only pathogen detected was M.pneumoniae. In this patient, serology was not helpful in establishing the diagnosis of M.pneumoniae related diseases, as was suggested before for older patients. We suggest that M.pneumoniae related empyema is probably under-diagnosed complication due to insensitivity of serology in older patients and under use of other diagnosis methods.

Evaluation of the polymerase chain reaction method for detection of Streptococcus pneumoniae DNA in pleural fluid samples

STUDY OBJECTIVE

Streptococcus pneumoniae is the most frequent causative agent of community-acquired pneumonia (CAP); however, an etiologic diagnosis by traditional techniques can be accomplished in only a small percentage of patients with CAP. Pleural fluid is present in approximately 40% of patients with CAP; therefore, we hypothesized that detection of S pneumoniae DNA in pleural fluid by polymerase chain reaction (PCR) may help to increase the rate of diagnosis of pneumococcal pneumonia.

DESIGN

A prospective study of cases.

SETTING

A university hospital in Lleida, Spain.

PATIENTS AND METHODS

One hundred two samples of pleural fluid (51 samples from consecutive adult patients with pneumonia and 51 samples from unselected control subjects) were tested by the nested-PCR method to detect selected pneumolysin gene of S pneumoniae, and the results were compared with those provided by alternative diagnostic methods.

RESULTS

PCR in pleural fluid had a diagnostic sensitivity of 78% in patients with pneumococcal pneumonia, with positive results in 2 of 2 patients (100%) and 5 of 7 patients (71%) who had positive or negative pleural fluid culture findings, respectively. PCR results were also positive in 3 of 24 patients (12%) with pneumonia of unknown etiology and negative in all patients with pneumonia due to microorganisms other than S pneumoniae. Thus, the calculated specificity was 93%. Among control subjects, PCR gave positive results in two cases (4%).

CONCLUSION

The nested-PCR test, applied to pleural fluid samples from patients with CAP, showed a sensitivity of 78% and a specificity of 93% in the diagnosis of pneumococcal pneumonia.

Significant role of interleukin-8 in pathogenesis of pulmonary disease due to Mycoplasma pneumoniae infection

We found elevated levels of interleukin-8 in pleural fluid samples from patients with pleural effusion and with a sustained fibrotic change of the lung due to Mycoplasma pneumoniae infection. This result suggests a critical role of interleukin-8 in the pathogenesis of a certain type of pulmonary disease caused by M. pneumoniae.

Close association between pulmonary disease manifestation in Mycoplasma pneumoniae infection and enhanced local production of interleukin-18 in the lung, independent of gamma interferon

To investigate pathophysiologies of Mycoplasma pneumoniae infection from an immunological point of view, we measured the levels of interleukin-18 (IL-18) (originally designated gamma interferon [IFN-gamma]-inducing factor) in 19 serum samples from 10 patients with pneumonia without pleural effusion (ages 1 to 16 years), 3 serum and 13 pleural fluid samples from 11 patients with pleural effusions (ages 11 months to 15 years), and 18 serum and 27 cerebrospinal fluid samples from 24 patients with central nervous system complications (ages 1 to 15 years). IL-18 was measured by a commercially available enzyme-linked immunosorbent assay kit (MBL, Nagoya, Japan). In addition, the levels of tumor necrosis factor alpha, IFN-gamma, IL-6, IL-12, and KL-6 (a mucin-like glycoprotein expressed on type 2 pneumocytes) were measured in selected samples. The results concerning pleural effusions showed that elevated levels of IL-18 in pleural fluid, but not in serum, were solely associated with a sustained fibrotic change of the lung on chest roentgenography which might represent a pathological feature of intraluminal organization. All the pleural fluid samples with elevated levels of IL-18 were positive by PCR for M. pneumoniae DNA. There was no association between IL-18 and IFN-gamma levels in serum or in the pleural fluid. On the other hand, elevated levels of IL-18 in serum, but not in cerebrospinal fluid samples, were observed in the cases complicated by central nervous system involvement, including profound brain dysfunction with seizures. Our study demonstrated that M. pneumoniae can induce IL-18 and that the enhanced local production of IL-18 in the lung is closely associated with pulmonary disease manifestation.

[Mycoplasma pneumoniae pneumonia in a four-year-old child with transient abscess in the right lower lobe]

The frequency of Mycoplasma pneumoniae infection among community-acquired pneumonia, underestimated for a long time, is now better known. Severe evolution is yet uncommon. Differential diagnosis with Streptococcus pneumoniae is often difficult.

CASE REPORT

A 4-year-old child was admitted for a right lower lobe pneumonia, with very high values of white blood cell count and CRP, worsening despite a treatment with high doses of amoxicillin, then with cefotaxime and vancomycin. Diagnosis of M. pneumoniae infection was considered only on the tenth day after admission and confirmed on the thirteenth day. Clinical outcome rapidly improved with macrolide antibiotherapy. Radiologic outcome consisted, two months after the beginning of the pneumonia, in abscess of the right lower lobe, which recovered in one month with continuing oral antibiotherapy.

CONCLUSION

Lung abscess is very rare in M. pneumoniae pneumonia, as only two other cases were described in the literature. In all three cases, macrolide therapy was delayed. Those cases highlight the importance of considering M. pneumoniae infection in a beta-lactams-resistant community-acquired pneumonia, whatever its severity may be, and to start macrolide antibiotherapy. Our case also shows the possibility of a conservative treatment in case of pulmonary abscess, if clinical tolerance is good.

Status of new medicines approved by the European Medicines Evaluation Agency regarding paediatric use

AIMS

To evaluate the activity of the European Medicines Evaluation Agency with regard to the registration for paediatric use of new medicines granted a marketing authorization.

METHODS

European Public Assessment Reports published on the Internet from January 95 until April 98 have been analysed using the browser Microsoft Explorer and the software Adobe Acrobat Reader.

RESULTS

Of the 45 new substances licensed since January 95, 29 (64%) were of possible use in children but only 10 were licensed for paediatric use. For the 19 drugs of possible use in children, but not approved for such a use, in nine instances (47%) their summary of product characteristics reported that their use in children has not been established.

CONCLUSIONS

A change of practice by pharmaceutical companies and regulatory authorities is imperative so that children are not precluded from having the same rights to medicines as adults.

Is Streptococcus pneumoniae the leading cause of pneumonia of unknown etiology? A microbiologic study of lung aspirates in consecutive patients with community-acquired pneumonia

PURPOSE

Although a wide variety of recognized pathogens can cause community-acquired pneumonia, in many patients the etiology remains unknown after routine diagnostic workup. The aim of this study was to identify the causal agent in these patients by obtaining lung aspirates with transthoracic needle aspiration.

SUBJECTS AND METHODS

During a 15-month period, all consecutive patients with community-acquired pneumonia who were eligible for transthoracic needle aspiration were enrolled in the study. In addition to conventional microbial methods (culture of blood and sputum, serologic studies), we performed cultures and genetic and antigen tests for common respiratory pathogens in lung aspirates.

RESULTS

The study group consisted of 109 patients. Conventional microbial studies identified an etiology in 54 patients (50%), including Mycoplasma pneumoniae in 19 patients, Chlamydia pneumoniae in 9 patients, and Streptococcus pneumoniae in 9 patients. Among the remaining 55 patients, study of the lung aspiration provided evidence of the causal agent in 36 (65%). In 4 additional patients with a single microbial diagnosis by conventional methods, the lung sample provided evidence of an additional microorganism. The new pathogens detected by lung aspiration were S. pneumoniae in 18 patients, Haemophilus influenzae in 6 patients, Pneumocystis carinii in 4 patients, and C. pneumoniae in 3 patients; other organisms were identified in 4 patients.

CONCLUSIONS

In our study, S. pneumoniae was the leading cause of community-acquired pneumonia, accounting for 25% of all cases, including about one-third of the cases the cause of which could not be ascertained with routine diagnostic methods.

Fever without apparent source on clinical examination, lower respiratory infections in children, and other infectious diseases

This section focuses on issues in infectious disease that are commonly encountered in pediatric office practice. Paul McCarthy discusses recent literature regarding the evaluation and management of acute fevers without apparent source on clinical examination in infants and children and the evaluation of children with prolonged fevers of unknown origin. Jean Klig reviews recent literature about lower respiratory tract infection in children. Finally, Jeffrey Kahn discusses recent developments concerning rotavirus vaccine.