Two human pathogenic mycoplasma species, Mycoplasma pneumoniae and M. genitalium currently pose challenges for the clinical practice.M. pneumoniae is a common cause of community-acquired respiratory infections, which can lead to asymptomatic courses as well as severe atypical pneumonia. Extrapulmonary manifestations also occur. Since December 2023, a strong increase of reported cases has been registered in the federal state of Saxony, where reporting is mandatory. These numbers far exceed those from the previous ten years and are assumed to generally translate to the other federal states. The reason for this development is likely the reduced contact with the pathogen during the COVID-19 pandemic combined with a waning immunity in the population. Although there are no reliable data on an increase in the rate of severe cases, diagnostics and treatment must be adapted. The resistance rate to macrolides (which are primarily used in Germany) remains favorable at approximately 3%.M. genitalium is a sexually transmitted bacterium and is only causally relevant in a portion of male urethritis cases. While its epidemiological significance is limited, resistance to the guideline-recommended antibiotics azithromycin and moxifloxacin is increasing, reaching 69% and 25%, respectively, in samples tested in the German consulting laboratory in recent years. Even higher rates are to be expected in high-risk groups (e.g., men who have sex with men), where M. genitalium is relatively frequent. Under these conditions, therapy can only be successful with a resistance-guided treatment concept.This review summarizes the current state of knowledge on both pathogens.

Despite significant global reductions in cases of pneumonia during the last 3 decades, pneumonia remains the leading cause of post-neonatal mortality in children aged <5 years. Beyond the immediate disease burden it imposes, pneumonia contributes to long-term morbidity, including lung function deficits and bronchiectasis. Viruses are the most common cause of childhood pneumonia, but bacteria also play a crucial role. However, the optimal duration of antibiotic therapy for bacterial pneumonia remains uncertain in both low- and middle-income countries and in high-income countries. Knowing the optimal duration of antibiotic therapy for pneumonia is crucial for effective antimicrobial stewardship. This is especially important as concerns mount over rising antibiotic resistance in respiratory bacterial pathogens, which increases the risk of treatment failure. Numerous studies have focused on the duration of oral antibiotics and short-term outcomes, such as clinical cure and mortality. In contrast, only one study has examined both intravenous and oral antibiotics and their impact on long-term respiratory outcomes following pneumonia hospitalisation. However, study findings may be influenced by their inclusion criteria when children unlikely to have bacterial pneumonia are included. Efforts to differentiate between bacterial and non-bacterial pneumonia continue, but a validated, accurate, and simple point-of-care diagnostic test remains elusive. Without certainty that a child has bacterial pneumonia, determining the optimal duration of antibiotic treatment is challenging. This review examines the evidence for the recommended duration of antibiotics for treating uncomplicated pneumonia in otherwise healthy children and concludes that the question of duration is unresolved.

Several studies regarding infections caused by macrolide-resistant Mycoplasma pneumoniae have been reported in the last years in the United States, where the prevalence is approximately 10% but may range from 3% to even 80%. Macrolide-resistant M. pneumoniae may be associated with prolonged fever, hospital stay, and complications. Suspicion should be raised by non-response to macrolides, and detection can be achieved through routine reflexive testing of M. pneumoniae-positive specimens with a polymerase-chain reaction assay that rapidly predicts macrolide resistance. After timely initiation of an alternative antibiotic, prompt resolution of the disease is likely in most cases. This review summarizes current US data, offers some suggestions, and identifies knowledge gaps on this infection.

Mycoplasma pneumoniae (MP) is a common bacterial respiratory infection that can cause pneumonia, particularly in children. Previously published data have highlighted the high incidence of viral co-infections and the problem of increasing macrolide resistance in MP worldwide.

(1) to estimate the impact of viral infections circulating in a local population on the spectrum of co-infection in hospitalized children with Mycoplasma pneumoniae pneumonia (MPP), (2) to determine if there are differences in resistance mutation rate for samples from hospitals of Russia located in the European and Far East, (3) to describe genomic characteristics of MP from Russian patients during the MPP outbreaks in the fall-winter of 2023-2024.

The carriage of viral pathogens was analyzed by real-time PCR in children with MPP from the European Part and Far East of Russian Federation and compared with the infections from two control groups. The V region of the 23S gene and the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes were sequenced to detect resistance-associated mutations in MP. Whole-genome sequencing method was used to determine the genetic relationship of a Russian MP isolate with known MP isolates.

The 62% of patients with MPP had a viral co-infection, with HPIV and SARS-CoV-2 predominating at 47% and 12.4%, respectively. The 15% of patients were infected with two or more viruses. In the control groups, 21% of healthy children and 43% of healthy adults were infected with Coronaviruses and Human Parainfluenza Viruses (HPIV-3 and -4), respectively. The 2063 A/G mutation of the 23S gene was found in 40.8% of patients from European Russia and in 35.7% of patients from the Far East. The result of core genes demonstrates that the sequence obtained from Russia clusters with sequences from clade 1.

Both HPIV and SARS-CoV-2 circulated in the population among healthy children and adults in December 2023 and they also were predominated in children with MPP. The rate of macrolide resistance was ⁓40%, which is higher than in European countries and significantly lower than in patients from Asian countries. Phylogenetic analysis showed the MP genome form Russia related to P1 type 1 (clade 1).

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen of community-acquired pneumonia (CAP). Epidemics occur every 3-7 years especially in pediatric patients. We collected data from a large laboratory network in Germany to define the epidemiological dynamics in the pre- and post-COVID-19 pandemic period.

In this retrospective cohort study we included all patients that obtained targeted or multiplex PCR for M. pneumoniae from nasopharyngeal swabs, sputum or bronchoalveolar fluids from 2015 to 2024. Demographic data (age, sex, place of residence, in- or outpatient status) were compared between M. pneumoniae positive and negative patients and co-infections with bacterial or viral pathogens analyzed.

We screened 38,204 patients for M. pneumoniae. We identified 1448 cases (3.8%) of M. pneumoniae (48.8% females). Pediatric patients ≤ 18 years represented 75.7% of M. pneumoniae patients and 2.3% were ≥ 60 years. Incidence of M. pneumoniae increased in fourth quartile 2015 (16.2%), second quartile 2018 (14.8%) and fourth quartile 2023 (13.4%). No cases were detected during COVID-19 pandemic 2021. Young age (aOR 0.98 95%-CI 0.97-0.98), outpatient status (aOR 0.56 95%-CI 0.43-0.71) and year of testing (OR dependent on year of testing) were predictors of M. pneumoniae detection in multivariate analysis (p < 0.001). We observed a significant increase in outpatients with M. pneumoniae after COVID-19 pandemic (86.7 vs. 96.5%, p = < 0.001, aOR 0.25, 95% CI 0.15-0.4).

Empirical treatment of CAP patients often does not include coverage of M. pneumoniae. A more thorough implementation of available surveillance data into clinical routine, respective therapies could be adapted more quickly during epidemic outbreaks of M. pneumoniae infections.

During the winter 2023-2024, an upsurge of Mycoplasma pneumoniae (M.pneumoniae) was noted in the Netherlands. To investigate the distribution of M.pneumoniae sequence types from different patient populations and to explore genotypic macrolide resistance which is common in East Asia but not (yet) in Europe. M.pneumoniae positive throat/nasal samples from participatory respiratory surveillance, patients visiting general practitioners with an acute respiratory infection including community acquired pneumonia (CAP) and hospitalised patients with CAP were included, representing different disease severity. The M.pneumoniae were typed with multilocus sequence typing and the 23 S rRNA region was sequenced to determine macrolide resistance markers. In total, 153 M.pneumoniae were sequenced, six sequence types (STs) and only one bacterium with macrolide resistance marker were detected. No link between STs or bacterial load (PCR cycle threshold) and source population of M.pneumoniae was detected. In the Netherlands, the M.pneumoniae upsurge in 2023-2024 existed of multiple commonly found STs. No link between ST and severity of illness was detected. Macrolide resistance remained sporadic.

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen that causes community-acquired pneumonia in children. The clinical presentation of this pathogen can range from mild self-limiting illness to severe and refractory cases. Complications may occur, such as necrotizing pneumonia and respiratory failure. Extrapulmonary complications, including encephalitis, myocarditis, nephritis, hepatitis, or even multiple organ failure, can also arise. In this editorial, we discuss the clinical implications of the significant findings from the article "Serum inflammatory markers in children with M. pneumoniae pneumonia and their predictive value for mycoplasma severity" published by Wang et al. They reported that measuring lactic dehydrogenase, interleukin-6 levels, and D-dimer effectively predicts refractory M. pneumoniae pneumonia cases.

A cluster of macrolide-resistant Mycoplasma pneumoniae -causing community-acquired pneumonia was observed in children in North Dakota in 2024. Suspicion was raised by non-response to macrolides, with confirmation via a polymerase-chain reaction assay. Prompt improvement occurred after the initiation of alternative antibiotics.

In 2024, there have been increases in laboratory-confirmed infections caused by Mycoplasma pneumoniae worldwide. This case series highlights the increasing frequency of M. pneumoniae-positive PCR (polymerase chain reaction) specimens and an increased number of hospital admissions with M. pneumoniae clinical syndromes. Within this case series, we observed a change in the epidemiology and clinical burden of childhood M. pneumoniae disease in the post-COVID-19 era.

Mycoplasma pneumoniae causes atypical pneumonia in children and young adults. Its lack of a cell wall makes it resistant to beta-lactams, which are the first-line treatment for typical pneumonia. Current diagnostic tests are time-consuming and have low specificity, leading clinicians to administer empirical antibiotics. Using a LASSO regression simulation approach and blood microarray data from 107 children with pneumonia (including 30 M. pneumoniae) we identify eight different transcriptomic signatures, ranging from 3-10 transcripts, that differentiate mycoplasma pneumonia from other bacterial/viral pneumonias with high accuracy (AUC: 0.84-0.95). Additionally, we demonstrate that existing signatures for broadly distinguishing viral/bacterial infections and viral/bacterial pneumonias are ineffective in distinguishing M. pneumoniae from viral pneumonia. The new signatures are successfully validated in an independent RNAseq cohort of children with pneumonia, demonstrating their robustness. The high sensibility of these signatures presents a valuable opportunity to guide the treatment and management of M. pneumoniae pneumonia patients.

Community acquired lower respiratory tract infection (LRTI) is a leading cause for hospitalization in children and important cause for antibiotic prescription. We aimed to describe the aetiology of LRTI in children and analyse factors associated with bacterial or viral infection.

Patients aged < 19 years with a diagnosis of LRTI were identified from the Observational Medical Outcomes Partnership Common Data Model Database of Seoul National University Bundang Hospital from January 2005-July 2019, and their clinical characteristics were obtained from the electronic medical records and retrospectively reviewed.

Among 5,924 cases of LRTI, 74.2% were pneumonia and 25.8% were bronchiolitis/bronchitis. Patients' median age was 1.8 (interquartile range, 3.1) years and 79.9% were < 5 years old. Pathogens were identified in 37.8%; 69.1% were viral and 30.9% were bacterial/Mycoplasma pneumoniae. Respiratory syncytial virus was most common (70.9%) among viruses and M. pneumoniae (94.6%) was most common among bacteria. Viral LRTI was associated with winter, age < 2 years, rhinorrhoea, dyspnoea, lymphocytosis, thrombocytosis, wheezing, stridor, chest retraction, and infiltration on imaging. Bacteria/M. pneumoniae LRTI was associated with summer, age ≥ 2 years, fever, decreased breathing sounds, leucocytosis, neutrophilia, C-reactive protein elevation, and positive imaging findings (consolidation, opacity, haziness, or pleural effusion).

In children with LRTI, various factors associated with viral or bacterial/M. pneumoniae infections were identified, which may serve as guidance for antibiotic prescription.

For Mycoplasma pneumoniae (MP) infection in schools, the local Center for Disease Control and Prevention recommends nonpharmaceutical interventions, such as case isolation, school closures, suspension of group activities, reinforcement of ventilation and disinfection for influenza outbreaks. However, there is limited evidence supporting and evaluating the effectiveness of these interventions. On the basis of an outbreak of MP infection occurring in a primary school in Zhejiang Province, a susceptible-latent-overt infected-recessive infected-displaced (SEIAR) model was constructed to quantitatively evaluate the prevention and control effects by simulating the intervention measures mentioned above. With no intervention, the outbreak lasted 143 days, and the total attack rate (TAR) and total infection rate (TIR) reached 75.78% and 95.65%, respectively. The most effective single-intervention strategy was ventilation and disinfection (VD), with a TAR as low as 15.81% and a duration of outbreak (DO) of 61 days. The two- or three- combined intervention strategies, including all combinations with 90% VD, were more effective than the single-intervention strategy. In conclusion, the SEIAR model could effectively simulate the epidemic situation of MP and the intervention effect. For the outbreak of MP, the earlier comprehensive measures were taken, such as ventilation and disinfection, and case isolation, the better control effect would be.

Mycoplasma pneumoniae (MP) is the cause of Mycoplasma pneumoniae pneumonia (MPP) in children and adolescents, with the clinical manifestations highlighted by intermittent irritating cough, accompanied by headache, fever and muscle pain. This paper aimed to study the research status and focal points in MP infection, especially the common laboratory diagnostic methods and clinical treatment of Mycoplasma pneumoniae. Laboratory diagnostic methods include molecular assay, serological antibody detection, rapid antigen detection and isolation and culture. Polymerase chain reaction (PCR) is the gold standard with high sensitivity and specificity. The serological antibody can detect various immune antibodies qualitatively or quantitatively in serum. Rapid antigen can be detected faster, with no equipment environment requirements, which can be used for the early diagnosis of MP infection. While the culture growth cycle is long and insensitive, not recommended for routine diagnosis. Macrolides were the preferred drug for children with MPP, while the drug resistance rate was rising in China. Tetracycline can be substituted but was not recommended for children under 8 years of age, quinolone drugs are not necessary, severe MPP can be combined with glucocorticoids, involving the nervous or immune system can choose gamma globulin. Other treatments for MPP including symptomatic treatment which can alleviate symptoms, improve lung function and improve prognosis. A safe and effective vaccine needed to be developed which can provide protective immunity to children and will reduce the incidence of MPP.

Mycoplasma pneumoniae infections resurged globally in 2023-2024 after a three-year decline during the COVID-19 pandemic. We explored the incidence and severity of M pneumoniae infections in children and adolescents before, during, and after the pandemic.

This nationwide, population-based cohort study included all Danish children and adolescents aged 0-17 years with a positive M pneumoniae PCR test from May 1, 2016, to April 30, 2024. We obtained clinical details for patients hospitalised for 24 h or more. Risk ratios for infections, hospitalisations, and disease manifestations in 2023-2024 versus pre-COVID-19 seasons were calculated using Fisher's exact and Pearson's χ2 tests. A season was defined from May 1 to April 30.

Among the Danish population of 1,152,000 children and adolescents, 14,241 with a positive PCR test for M pneumoniae were included. In 2023-2024, children and adolescents with a positive PCR rose 2.9-fold (95% CI 2.8-3.1; p < 0.0001) compared to the pre-COVID-19 seasons, and hospitalisations rose 2.6-fold (95% CI 2.0-3.3; p < 0.0001). M pneumoniae-induced rash and mucositis increased 5.3-fold (95% CI 1.8-15.3; p = 0.0007). In 2023-2024 compared to the pre-COVID-19 seasons, there was no difference in the proportion of hospitalisation (360 [4%] of 8165 versus 230 [4%] of 6009; p = 0.09), the median duration of hospital stay (3 days [IQR 2-5] versus 3 days [IQR 2-5]; p = 0.84), or paediatric intensive care unit admission (14 [4%] of 360 versus 9 [4%] of 230 p = 1.00).

In Denmark, M pneumoniae infections and hospitalisations increased three-fold in 2023-2024 compared with the pre-COVID-19 seasons, indicating an immunity debt caused by the decline in M pneumoniae during the COVID-19 pandemic. While the severity of M pneumoniae infections did not change in 2023-2024, the five-fold increase in M pneumoniae-induced rash and mucositis in children and adolescents highlights M pneumoniae as an important pathogen causing mucocutaneous eruptions.

Innovation Fund Denmark and Rigshospitalets Forskningsfond.

Flock-level prevalence and characterization of Mycoplasma ovipneumoniae is determined almost exclusively using nasal swabbing followed by molecular detection with either quantitative PCR or multi-locus sequence typing. However, the diagnostic performance and efficiency of swabbing the nasal passage compared to other anatomical locations has not been determined within sheep populations. The goal of this research was to assess the diagnostic capability of nasopharyngeal swabs in comparison to nasal swabs for the detection of Mycoplasma ovipneumoniae.

Nasal and nasopharyngeal swabs were collected during a controlled exposure study of domestic sheep with Mycoplasma ovipneumoniae. Both swab types were then analyzed via conventional and quantitative PCR. This dataset showed that the use of nasopharyngeal swabs in lieu of nasal swabs resulted in higher sensitivity, reduced inhibition during quantitative PCR, and higher bacterial copy numbers per swab. Moreover, it was demonstrated that diagnostic sensitivity could be further increased during quantitative PCR via ten-fold dilution of the extracted DNA. To confirm these observations in naturally infected animals, we conducted a field study employing a production flock of domestic sheep using both nasal and nasopharyngeal swabbing techniques. Extracted DNA was assessed using the same molecular techniques, where detection of Mycoplasma ovipneumoniae was confirmed by sequencing of either the rpoB or 16S rRNA gene. Similar improvements were observed for nasopharyngeal swabs and template treatment methods within the naturally infected flock.

Results demonstrate increased diagnostic sensitivity and specificity when sampling with nasopharyngeal swabs as compared to nasal swabs. Therefore, alternate field-testing strategies employing nasopharyngeal swabs should be considered for diagnosis of the presence of M. ovipneumoniae. Importantly, sample treatment following acquisition was found to affect the sensitivity of quantitative PCR, where dilution of eluted DNA template doubled the calculated sensitivity. This demonstrates that, in addition to anatomical location, the presence of inhibitory components in swab extracts also strongly influences diagnostic performance.

Pharyngitis is an inflammatory condition of the pharynx and/or tonsils commonly seen in both children and adults. Viruses and bacteria represent the most common encountered etiologic agents-yeast/fungi and parasites are infrequently implicated. Some of these are predominantly observed in unique populations (eg, immunocompromised or unvaccinated individuals). This article (part 1 of 3) summarizes the impact of acute pharyngitis on the health care system and reviews the etiologic agents of acute pharyngitis, including both emerging and reemerging pathogens that health care providers should consider when evaluating their patients. Finally, it sets the stage for parts 2 and 3, which discuss the current and evolving state of diagnostic testing for acute pharyngitis.

Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in school-aged children. Macrolides are the first-line treatment for this infection. However, it is unclear whether macrolides are effective in treating M. pneumoniae CAP, mainly due to limitations in microbiological diagnosis of previous studies. The extensive global use of macrolides has led to increasing antimicrobial resistance. The overall objective of this trial is to produce efficacy data for macrolide treatment in children with M. pneumoniae CAP.

The MYTHIC Study is a randomized, double-blind, placebo-controlled, multicenter, non-inferiority trial in 13 Swiss pediatric centers. Previously healthy ambulatory and hospitalized children aged 3-17 years with clinically diagnosed CAP will be screened with a sensitive and commercially available M. pneumoniae-specific IgM lateral flow assay from capillary blood. Mycoplasma pneumoniae infection in screened patients will be verified retrospectively by respiratory PCR (reference test) and IgM antibody-secreting cell enzyme-linked immunospot (ELISpot) assay (confirmatory test for distinguishing between carriage and infection). Patients will be randomized 1:1 to receive a 5-day treatment of macrolides (azithromycin) or placebo. The co-primary endpoints are (1) time to normalization of all vital signs, including body temperature, respiratory rate, heart rate, and saturation of peripheral oxygen (efficacy), and (2) CAP-related change in patient care status (i.e., admission, re-admission, or intensive care unit transfer) within 28 days (safety). Secondary outcomes include adverse events (AEs), as well as antimicrobial and anti-inflammatory effects. For both co-primary endpoints, we aim to show non-inferiority of placebo compared to macrolide treatment. We expect no macrolide effect (hazard ratio of 1, absolute risk difference of 0) and set the corresponding non-inferiority margins to 0.7 and -7.5%. The "at least one" success criterion is used to handle multiplicity with the two co-primary endpoints. With a power of 80% to reject at least one null hypothesis at a one-sided significance level of 1.25%, 376 patients will be required.

This trial will produce efficacy data for macrolide treatment in children with M. pneumoniae CAP that might help to reduce the prescription of antibiotics and therefore contribute to the global efforts toward reducing antimicrobial resistance.

ClinicalTrials.gov, NCT06325293. Registered on 24 April 2024.

Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia among school-aged children and young adults. Infections occur throughout the year but tend to surge during winter months across Europe. A characteristic epidemic cycle, where a substantial surge in the number of infections occurs, is seen approximately every 1-4 years and hypothesized to be driven by changes in immunity and a shift in circulating variants. Once thought to be an organism of low virulence, it has now been found to possess several virulence factors, including toxin production, biofilm formation and evasion of antibody-mediated immunity. The lack of a cell wall and reduced metabolic pathways limit the options for antibiotic treatment. Acquired macrolide resistance is a growing concern, with >80% of cases in China being macrolide-resistant. Although efforts have been made to develop a vaccine, there are still substantial hurdles to overcome in relation to vaccine-enhanced disease, which results from an inappropriate immune response among vaccinated individuals.

Mycoplasma pneumoniae (M. pneumoniae) is a bacterium with particular characteristics that give rise to a broad clinical spectrum, being respiratory infection the most frequent presentation. Infection by M. pneumoniae occurs in cyclical epidemics, and paediatricians in Spain have noticed an increase in cases since January 2024, establishing hospital registers to collect surveillance data (as it is not a notifiable disease in Spain). The diagnosis of infection by M. pneumoniae is made through serological testing and/or the detection of genetic material by means of polymerase chain reaction (PCR). Neither methods can differentiate between colonization and active infection, so a precise diagnosis is not possible and testing should only be requested in the case of high clinical suspicion. The role of antibiotherapy in infection by M. pneumoniae in its different clinical variants is not well defined. Most infections are self-limiting and mild, and there is insufficient evidence to support the use of antibiotherapy in these cases. Antibiotic treatment is justified in patients with risk factors for the development of severe disease (Down syndrome, anatomical or functional asplenia, immunosuppression), in hospitalized patients with respiratory infection and in patients with moderate or severe extrapulmonary forms. Taking into account aspects concerning the rational use of antimicrobials, the treatment of choice would be clarithromycin, with azithromycin as an alternative, reserving the use of doxycycline and levofloxacin for cases of antimicrobial resistance and/or infections of the central nervous system.

Background: Mycoplasma pneumoniae (M. pneumoniae) infections can progress to severe respiratory complications, necessitating intensive care treatment. Recent post COVID-19 pandemic surges underscore the need for timely diagnosis, given potential diagnostic method limitations. Methods: A retrospective case series analysis was conducted on M. pneumonia PCR-positive patients admitted to two Dutch secondary hospitals' ICUs between January 2023 and February 2024. Clinical presentations, treatments, outcomes, and mechanical ventilation data were assessed. Results: Seventeen ICU-admitted patients were identified, with a median age of 44 years, primarily due to hypoxia. Non-invasive ventilation was effective for most, while five required invasive mechanical ventilation. None of the patients required extracorporeal membrane oxygenation. No fatalities occurred. Post-PCR, treatment was adjusted to doxycycline or azithromycin; seven received steroid treatment. Discussion: Increased ICU admissions for M. pneumoniae infection were observed. Diverse clinical and radiological findings emphasize heightened clinical awareness. Early molecular diagnostics and tailored antibiotic regimens are crucial since beta-lactam antibiotics are ineffective. Conclusion: This study highlights the escalating challenge of severe M. pneumoniae infections in ICUs, necessitating a multifaceted approach involving accurate diagnostics, vigilant monitoring, and adaptable treatment strategies for optimal patient outcomes.

The aim of the study was to develop an experimental version of a DNA microarray for parallel detection of community-acquired pneumonia bacterial pathogens.

We studied the samples of the pharyngeal mucosa smears taken from children aged 1-15 years with X-ray confirmed pneumonia. The selection of DNA probes for specific detection of community-acquired pneumonia pathogens (S. pneumoniae, H. influenzae, M. pneumoniae, C. pneumonia, and L. pneumophila) and development of the microarray design were carried out using the disprose program. The nucleotide sequences of pathogens were obtained from NCBI Nucleotide database. In the research we used CustomArray microarrays (USA). For a pooled sample containing S. pneumoniae and H. influenzae DNA, we performed a sequential selection of the best combinations of hybridization parameters: DNA fragment size, DNA amount, hybridization temperature. The selection criteria were: the percentage of effective probes with a standardized hybridization signal (SHS) ≥3 Z, and the excess of SHS levels of effective specific probes compared to SHS of effective nonspecific probes. We selected the probes to detect of S. pneumoniae and H. influenzae characterized by an effective hybridization signal under optimal conditions. The developed microarray was tested under the selected conditions on clinical samples containing S. pneumoniae or H. influenzae DNA. Using ROC analysis there were established threshold values for the signals of specific probes at optimal sensitivity points and the test specificity, the excess of which was interpreted as the evidence of pathogen presence in a sample.

A microarray design included 142 DNA probes to detect S. pneumoniae, H. influenzae, M. pneumoniae, C. pneumoniae, and L. pneumophila, the probes being synthesized onto slides. Using the example of clinical samples containing S. pneumoniae and/or H. influenza DNA, we selected optimal parameters for DNA hybridization on microarrays, which enabled to identify bacterial pathogens of community-acquired pneumonia with sufficient efficiency, specificity and reproducibility: the amount of hybridized DNA was 2 μg, the DNA fragment size: 300 nt, hybridization temperature: 47°C. There was selected a list of probes for specific detection of S. pneumoniae and H. influenzae characterized by an effective hybridization signal under the identified conditions. We determined the threshold values of standardized probe signals for specific detection of S. pneumoniae (4.5 Z) and H. influenzae (4.9 Z) in clinical samples.

A DNA microarray was developed and synthesized for parallel indication of bacterial pathogens of community-acquired pneumonia. There were selected the optimal parameters for DNA hybridization on a microarray to identify bacterial pathogens - S. pneumoniae and H. influenzae, and determined the threshold values of significant probe signals for their specific detection. The interpretation of the microarray hybridization results corresponds to those obtained by PCR. The microarray can be used to improve laboratory diagnostics of community-acquired pneumonia pathogens.

Pneumonia is a common pediatric infectious disease that is familiar to pediatricians and a major cause of hospitalization worldwide. Recent well-designed epidemiologic studies in developed countries indicated that respiratory viruses are detected in 30%-70%, atypical bacteria in 7%-17%, and pyogenic bacteria in 2%-8% of children hospitalized with community-acquired pneumonia (CAP). The etiological distribution of CAP varies widely by child age and the epidemiological season of the respiratory pathogen. Moreover, diagnostic tests, particularly for the detection of Streptococcus pneumoniae and Mycoplasma pneumoniae, the 2 major bacterial pathogens involved in pediatric CAP, have several limitations. Therefore, management and empirical antimicrobial therapy for children with CAP should be applied in a stepwise manner based on recent epidemiological, etiological, and microbiological evidence.

Mycoplasma pneumoniae is an important cause of pneumonia and extra-pulmonary manifestations. We observed a rise in admissions due to M. pneumoniae infections starting October 2023 in a regional hospital in the Netherlands and an increased incidence in national surveillance data. The incidence in the Netherlands has not been that high since 2011. The patients had a lower median age compared with 2019 and 2020 (28 vs 40 years). M. pneumoniae should be considered in patients with respiratory symptoms, especially children.

Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD). Although respiratory pathogens are frequently detected in children with ACS, their respective role in triggering the disease is still unclear. We hypothesized that the incidence of ACS followed the unprecedented population-level changes in respiratory pathogen dynamics after COVID-19-related nonpharmaceutical interventions (NPIs).

What is the respective role of respiratory pathogens in ACS epidemiology?

This study was an interrupted time series analysis of patient records from a national hospital-based surveillance system. All children aged < 18 years with SCD hospitalized for ACS in France between January 2015 and May 2022 were included. The monthly incidence of ACS per 1,000 children with SCD over time was analyzed by using a quasi-Poisson regression model. The circulation of 12 respiratory pathogens in the general pediatric population over the same period was included in the model to assess the fraction of ACS potentially attributable to each respiratory pathogen.

Among the 55,941 hospitalizations of children with SCD, 2,306 episodes of ACS were included (median [interquartile range] age, 9 [5-13] years). A significant decrease was observed in ACS incidence after NPI implementation in March 2020 (-29.5%; 95% CI, -46.8 to -12.2; P = .001) and a significant increase after lifting of the NPIs in April 2021 (24.4%; 95% CI, 7.2 to 41.6; P = .007). Using population-level incidence of several respiratory pathogens, Streptococcus pneumoniae accounted for 30.9% (95% CI, 4.9 to 56.9; P = .02) of ACS incidence over the study period and influenza 6.8% (95% CI, 2.3 to 11.3; P = .004); other respiratory pathogens had only a minor role.

NPIs were associated with significant changes in ACS incidence concomitantly with major changes in the circulation of several respiratory pathogens in the general population. This unique epidemiologic situation allowed determination of the contribution of these respiratory pathogens, in particular S pneumoniae and influenza, to the burden of childhood ACS, highlighting the potential benefit of vaccine prevention in this vulnerable population.

Mycoplasma pneumoniae is a self-propagating microorganism that commonly causes respiratory tract infections. It can also cause a variety of extrapulmonary symptoms with or independently of respiratory symptoms, such as skin lesions, arthralgia, myalgia, hemolysis, cardiac lesions, gastrointestinal symptoms, and central nervous system lesions, which are rare manifestations reported in approximately 0.1% of cases. In this study, we present a unique case of Mycoplasma-related abducens nerve palsy, polyarthritis, and erythema multiforme without respiratory disease. The patient was a 69-year-old woman who presented to our hospital with a skin rash, fever, arthralgia, and diplopia without respiratory symptoms. Brain magnetic resonance imaging showed optic neuritis on the right side, suggesting the diplopia was caused by right abducens nerve palsy. However, the etiologies of abducens nerve palsy were not revealed by the physical examination, blood biochemistry tests, or bacteriological examinations, including the cerebrospinal fluid examination obtained at admission. Mycoplasma infection was suspected from erythema multiforme revealed by a skin biopsy and polyarthralgia, and it was finally diagnosed according to elevated Mycoplasma particle agglutination (PA) antibodies in paired serum. Though minocycline did not improve her diplopia, the daily administration of 30 mg of prednisolone gradually improved her symptoms, and the Mycoplasma PA antibody titer, which was regularly measured in the clinical course, also decreased, suggesting a relationship between Mycoplasma infection and abducens nerve palsy. This is the first case of isolated abducens nerve palsy, which was reported as the only central neurological symptom in an adult patient with Mycoplasma infection. The mechanism or pathogenesis of CNS manifestations caused by Mycoplasma pneumoniae remains to be elucidated, and further investigation is needed. Hence, Mycoplasma infection is a common disease. Clinicians should be aware of the diverse manifestations, including abducens nerve palsy, of Mycoplasma infection and should consider Mycoplasma infection even in the absence of typical respiratory symptoms.

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in school-aged children and can be preceded by asymptomatic carriage. However, its role in recurrent respiratory tract infections is unclear. We studied the prevalence of M.pneumoniae carriage in children with recurrent respiratory infections and identified associated factors.

We tested M.pneumoniae carriage by qPCR in children with recurrent infections and their healthy family members in a cross-sectional study. Serum and mucosal total and M.pneumoniae-specific antibody levels were measured by ELISA and nasopharyngeal microbiota composition was characterized by 16S-rRNA sequencing.

Prevalence of M.pneumoniae carriage was higher in children with recurrent infections (68%) than their family members without infections (47% in siblings and 27% in parents). M.pneumoniae carriage among family members appeared to be associated with transmission within the household, likely originating from the affected child. In logistic regression corrected for age and multiple comparisons, IgA (OR 0.16 [0.06-0.37]) and total IgG deficiency (OR 0.15 [0.02-0.74]) were less prevalent in M.pneumoniae carriers (n = 78) compared to non-carriers (n = 36). In multivariable analysis, the nasopharyngeal microbiota of M.pneumoniae carriers had lower alpha diversity (OR 0.27 [0.09-0.67]) and a higher abundance of Haemophilus influenzae (OR 45.01 [2.74-1608.11]) compared to non-carriers.

M.pneumoniae carriage is highly prevalent in children with recurrent infections and carriers have a less diverse microbiota with an overrepresentation of disease-associated microbiota members compared to non-carriers. Given the high prevalence of M.pneumoniae carriage and the strong association with H. influenzae, we recommend appropriate antibiotic coverage of M.pneumoniae and H. influenzae in case of suspected pneumonia in children with recurrent respiratory tract infections or their family members.

Wilhelmina Children's Hospital Research Fund, 'Christine Bader Stichting Irene KinderZiekenhuis', Sophia Scientific Research Foundation, ESPID Fellowship funded by Seqirus, Hypatia Fellowship funded by Radboudumc and The Netherlands Organisation for Health Research and Development (ZonMW VENI grant to LM Verhagen).

There have been many epidemiologic studies on community-acquired pneumonia (CAP) among children, most of which had substantial limitations. This study investigated the etiologic distribution and clinical characteristics of CAP in Korean children for 5 years before the coronavirus disease 2019 (COVID-19) pandemic.

A retrospective analysis of children hospitalized for CAP at 4 referral hospitals during 2015-2020 was performed. Cases in which bronchiolitis was suspected or pulmonary infiltration was not evident on chest radiography (CXR) were excluded. Viruses and atypical bacteria were defined as detected when positive in the polymerase chain reaction test performed for respiratory specimens. Serologic testing result for Mycoplasma pneumoniae was incorporated with strict interpretation. Pyogenic bacteria were included only when cultured in blood, pleural fluid, or bronchoalveolar lavage, but those cultured in endotracheal aspirate or sputum when the case was clinically evident bacterial pneumonia were also included.

A total of 2,864 cases of suspected pneumonia were selected by diagnosis code and CXR findings. Medical chart and CXR review excluded nosocomial pneumonia and cases without evident infiltration, resulting in 517 (18.1%) CAP cases among 489 children. Regarding clinical symptoms, high fever was present in 59.4% and dyspnea in 19.9% of cases. Respiratory support was required for 29.2% of patients, including mechanical ventilation for 3.9%. Pathogens were detected in 49.9% of cases, with viruses in 32.3%, atypical bacteria in 17.8%, and pyogenic bacteria in 2.3% of cases. As single pathogens, M. pneumoniae (16.8%) and respiratory syncytial virus (RSV, 13.7%) were the most common. Parenteral β-lactam and macrolide antibiotics were administered in 81.6% and 50.7% of cases, respectively. A total of 12 (2.3%) cases resulted in poor outcomes, including 3 deaths.

M. pneumoniae and RSV were the most commonly detected pathogens of pediatric CAP, which was selected by strict clinical and radiologic criteria. It is necessary to carefully decide whether to use parenteral antibiotics based on the epidemiology and clinical features of CAP in children.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been the most significant public health challenge in over a century. SARS-CoV-2 has infected over 765 million people worldwide, resulting in over 6.9 million deaths. This study aimed to detect community transmission of SARS-CoV-2 and monitor the co-circulation of SARS-CoV-2 with other acute respiratory pathogens in Rift Valley, Kenya.

We conducted a cross-sectional active sentinel surveillance for the SARS-CoV-2 virus among patients with acute respiratory infections at four sites in Rift Valley from January 2022 to December 2022. One thousand two hundred seventy-one patients aged between 3 years and 98 years presenting with influenza-like illness (ILI) were recruited into the study. Nasopharyngeal swab specimens from all study participants were screened using a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus (RSV).

The samples that tested positive for influenza A (n = 73) and RSV (n = 12) were subtyped, while SARS-CoV-2 (n = 177) positive samples were further screened for 12 viral and seven bacterial respiratory pathogens. We had a prevalence of 13.9% for SARS-CoV-2, 5.7% for influenza A, 2% for influenza B and 1% for RSV. Influenza A-H1pdm09 and RSV B were the most dominant circulating subtypes of influenza A and RSV, respectively. The most common co-infecting pathogens were Streptococcus pneumoniae (n = 29) and Haemophilus influenzae (n = 19), accounting for 16.4% and 10.7% of all the SARS-CoV-2 positive samples.

Augmenting syndromic testing in acute respiratory infections (ARIs) surveillance is crucial to inform evidence-based clinical and public health interventions.

This study aimed to evaluate the diagnostic value of chemiluminescence immunoassay (CLIA), passive particle agglutination (PPA), and indirect immunofluorescence assay (IFA) in detecting Mycoplasma pneumoniae infection in children. Serum samples from 165 children with acute community-acquired respiratory tract infections were examined using CLIA, PPA, and IFA, and consistency coefficient, specificity, and sensitivity were analyzed. Compared with the PPA (titer ≥ 1:160), the consistency coefficients of the immunoglobulin(Ig)M-CLIA, immunoglobulin(Ig)G-CLIA and IgM-IFA methods were 93.94%, 75.76%, and 83.64%, respectively. The positive likelihood ratio (PLR) and specificity of IgM-CLIA was 19.40 and 95.49%, respectively. The consistency coefficient of (IgM+IgG)-CLIA and PPA (titer ≥ 1:160) was 89.1%, and the sensitivity and negative predictive value of (IgM+IgG)-CLIA were 96.88% and 98.94%, respectively. CLIA MP-IgM has high concordance with PPA, and its specificity and sensitivity are higher than those of CLIA MP-IgG and IFA MP-IgM, suggesting its better diagnosis of early MP infection. The sensitivity and negative predictive value of CLIA MP (IgM+IgG) were higher than those of PPA or IFA, indicating that it should be considered as a priority in the diagnosis of MP infection.

Mycoplasma pneumoniae is a common causative pathogen of community-acquired pneumonia. An accurate and sensitive detection method is important for evaluating disease severity and treatment efficacy. Digital droplet PCR (ddPCR) is a competent method enabling the absolute quantification of DNA copy number with high precision and sensitivity. We established ddPCR for M. pneumoniae detection, using clinical specimens for validation, and this showed excellent specificity for M. pneumoniae. The limit of detection of ddPCR was 2.9 copies/reaction, while that for real-time PCR was 10.8 copies/reaction. In total, 178 clinical samples were used to evaluate the ddPCR assay, which correctly identified and differentiated 80 positive samples, whereas the real-time PCR tested 79 samples as positive. One sample that tested negative in real-time PCR was positive in ddPCR, with a bacterial load of three copies/test. For samples that tested positive in both methods, the cycle threshold of real-time PCR was highly correlated with the copy number of ddPCR. Bacterial loads in patients with severe M. pneumoniae pneumonia were significantly higher than those in patients with general M. pneumoniae pneumonia. The ddPCR showed that bacterial loads were significantly decreased after macrolide treatment, which could have reflected the treatment efficacy. The proposed ddPCR assay was sensitive and specific for the detection of M. pneumoniae. Quantitative monitoring of bacterial load in clinical samples could help clinicians to evaluate treatment efficacy.

Mycoplasma pneumoniae (Mp) is a common cause of lower respiratory tract infection (LRTI) in children that is difficult to distinguish from LRTI of other etiologies. We aimed to determine if a combination of clinical, laboratory, and chest radiographic features can help identify patients at higher risk of Mp LRTI. We reviewed medical charts of children referred to our tertiary hospital with suspected acute mycoplasmal LRTI. Pharyngeal swabs obtained from patients were tested by Mp PCR. We compared epidemiological and clinical data of children with positive and negative Mp PCR results. In addition, a multivariable logistic regression analysis was performed to predict Mp LRTI based on the patient's age, duration of symptoms, presence of extrapulmonary manifestations, laboratory findings, and chest radiographic findings. We included 65 children with Mp PCR-negative and 49 with Mp PCR-positive LRTI and no viral co-detection. Children with Mp LRTI were older (median age 5.8 vs. 2.2 years, p < 0.001), had a longer duration of symptoms on referral (median 7 vs. 4 days, p < 0.001), and lower median WBC (9.9 vs. 12.7 × 109/L, p < 0.001). On chest radiograph, unilateral infiltrates were more frequently observed in the Mp PCR-positive group (57.5% vs. 24.1%, p = 0.001). Age, duration of symptoms, and chest radiographic findings had the highest predictive value for Mp LRTI in a multivariable logistic regression model. Our analysis suggests that a combination of clinical, laboratory, and chest radiographic features can be used to assess the likelihood of Mp LRTI and assist in decision-making for which children need further tests or macrolide antibiotic treatment.

Mycoplasma pneumoniae is an important pathogen causing upper and lower respiratory tract infections in children and other age groups. Macrolides are the recommended treatments of choice for M. pneumoniae infections. However, macrolide resistance in M. pneumoniae is increasing worldwide, which complicates the treatment strategies. The mechanisms of macrolide resistance have been extensively studied focusing on the mutations in 23S rRNA and ribosomal proteins. Since the secondary treatment choice for pediatric patients is very limited, we decided to look for potential new treatment strategies in macrolide drugs and investigate possible new mechanisms of resistance. We performed an in vitro selection of mutants resistant to five macrolides (erythromycin, roxithromycin, azithromycin, josamycin, and midecamycin) by inducing the parent M. pneumoniae strain M129 with increasing concentrations of the drugs. The evolving cultures in every passage were tested for their antimicrobial susceptibilities to eight drugs and mutations known to be associated with macrolide resistance by PCR and sequencing. The final selected mutants were also analyzed by whole-genome sequencing. Results showed that roxithromycin is the drug that most easily induces resistance (at 0.25 mg/L, with two passages, 23 days), while with midecamycin it is most difficult (at 5.12 mg/L, with seven passages, 87 days). Point mutations C2617A/T, A2063G, or A2064C in domain V of 23S rRNA were detected in mutants resistant to the 14- and 15-membered macrolides, while A2067G/C was selected for the 16-membered macrolides. Single amino acid changes (G72R, G72V) in ribosomal protein L4 emerged during the induction by midecamycin. Genome sequencing identified sequence variations in dnaK, rpoC, glpK, MPN449, and in one of the hsdS (MPN365) genes in the mutants. Mutants induced by the 14- or 15-membered macrolides were resistant to all macrolides, while those induced by the 16-membered macrolides (midecamycin and josamycin) remained susceptible to the 14- and 15-membered macrolides. In summary, these data demonstrated that midecamycin is less potent in inducing resistance than other macrolides, and the induced resistance is restrained to the 16-membered macrolides, suggesting a potential benefit of using midecamycin as a first treatment choice if the strain is susceptible.

The worldwide increase in the incidence of antibiotic resistance of the atypical bacterium Mycoplasma pneumoniae (MP) challenges the treatment of MP infections, especially in children. Therefore, alternative strategies for the treatment of MP infections are warranted. Galacto- and fructo-oligosaccharides (GOS and FOS) are a specific group of complex carbohydrates that were recently shown to possess direct anti-pathogenic properties. In this study, we assessed whether GOS and FOS exert anti-microbial and anti-infective effects against MP and, especially, macrolide-resistant MP (MRMP) in vitro. The MIC values of GOS for MP and MRMP were 4%. In contrast, the MIC values of FOS for both MP and MRMP were 16%. A time-kill kinetic assay showed that FOS possess bacteriostatic properties, while for GOS, a bactericidal effect against MP and MRMP was observed after 24 h at a concentration of 4x MIC. In co-cultures with human alveolar A549 epithelial cells, GOS killed adherent MP and MRMP and also concentration-dependently inhibited their adherence to A549 cells. Further, GOS suppressed (MR)MP-induced IL-6 and IL-8 in A549 cells. None of the aforementioned parameters were affected when FOS were added to these co-cultures. In conclusion, the anti-infective and anti-microbial properties of GOS could provide an alternative treatment against MRMP and MP infections.

We aimed to assess whether detection of respiratory bacteria by multiplex polymerase chain reaction (PCR) testing associates with clinical outcomes in acutely ill children.

This cross-sectional study enrolled children under the age of 18 with a suspected respiratory infection treated in a paediatric emergency department of Oulu University Hospital, Finland from January 2015 through December 2015. Nasopharyngeal samples were routinely analysed for 16 respiratory viruses and later, after storage, analysed with a multiplex PCR panel for seven respiratory bacteria.

At least one bacterial pathogen was detected in 600 out of the 1195 children (50%). The mean age was 3.3 (SD 3.7) years and 54% were boys. Atypical bacteria were associated with a risk of pneumonia (adjusted odds ratio [aOR] 14.1, 95% CI 3.98-50.1). Co-detection of rhinovirus with Streptococcus pneumoniae was not associated with risk of pneumonia (aOR 2.39, 95% CI 0.78-7.30). Detection of Streptococcus pneumoniae, Haemophilus influenzae or both was not associated with the risk of hospital admission or prescription of antibiotics.

Nasopharyngeal detection of atypical bacteria in acutely ill children was associated with a markedly increased risk of pneumonia. The clinical utility of wide testing for other respiratory bacteria needs further evaluation.