The differential diagnosis of pneumonia in two patients infected by atypical pathogens.

The current study presents two patients who lived in a rural family with close contact and suffered from rapidly progressive pneumonia. Chest computed tomography images and lymphocytopenia indicated the possibility of COVID-19 infection, but antibody and nucleic acid tests excluded this possibility. Negative results were obtained from corresponding tests for pneumococcal, adenovirus, fungal and legionella infection. Metagenomics analysis and subsequent antibody tests confirmed mycoplasma pneumonia. After treating with moxifloxacin, both patients recovered well and left the hospital. In terms of complicated infectious disease, consideration of atypical pathogens and medical and epidemiological history were important for differential diagnosis of COVID-19; metagenomics analysis was useful to provide direct references for diagnosis.

In vitro susceptibility test of Xiao'er Feire Kechuan Oral Solution to Mycoplasma pneumoniae.

The aim of this study was to evaluate the inhibitory effect of antibiotics and Xiao'er Feire Kechuan Oral Solution on Mycoplasma pneumoniae (MP) clinical isolates.Twenty clinical isolates containing A-to-G transition at position 2063 and 10 clinical isolates without mutations in 23S rRNA V regions were randomly selected. The international standard strain FH was chosen as control strain. The minimum inhibitory concentration (MIC) of macrolide, quinolones, tetracycline, and Xiao'er Feire Kechuan Oral Solution to MP clinical isolates were performed using broth microdilution method.In vitro antibiotic susceptibility test of MP clinical isolates showed that MP showed high resistance to macrolide antibiotics (erythromycin and azithromycin); MIC of both were more than 64 µg/mL. The MICs of erythromycin and azithromycin for clinical isolates without mutations in 23S rRNA V regions were ≤0.5 µg/mL. The MICs of tetracycline and levofloxacin for all clinical isolated strains were ≤2.0 µg/mL and ≤1.0 µg/mL, respectively. The MIC of Xiao'er Feire Kechuan Oral Solution was 13.828∼6.914 mg/mL.In vitro, the drug resistance of MP to macrolide antibiotics is higher, MP clinical isolates are sensitive to tetracycline and levofloxacin, and Xiao'er Feire Kechuan Oral Solution also has a certain inhibitory effect on the macrolide-resistant MP.

Comparing Antimicrobial Susceptibilities among Mycoplasma pneumoniae Isolates from Pediatric Patients in Japan between Two Recent Epidemic Periods.

We compared the antimicrobial susceptibility of Mycoplasma pneumoniae isolates from pediatric patients in Japan in 2011-2012 and 2015-2016, when epidemics occurred. The antimicrobial activity of macrolides and tetracyclines against M. pneumoniae infection tended to be restored in 2015-2016. There was no change in the antimicrobial activity of quinolones against M. pneumoniae infection.

Genetic diversity and macrolide resistance of Mycoplasma pneumoniae isolates from two consecutive epidemics in Slovenia.

Two nationwide Mycoplasma pneumoniae epidemics occurred in Slovenia between 2006 and 2016. The aim of this study was to assess which M. pneumoniae genotypes were present in our area during the selected timeframe, whether the origin of the epidemics was monoclonal or polyclonal and whether the proportion between detected genotypes changed over time. We were also interested in the presence of macrolide resistance (MR) and whether it could be linked to specific genotypes. We performed pyrosequencing of the P1 gene and multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) typing from 872 M. pneumoniae isolates obtained from respiratory tract infections (RTI)-suffering patients. Additionally, isolates were tested for the presence of MR implicated mutations in the 23S rRNA gene. The MLVA typing results revealed that three main genotypes, MLVA-3,5,6,2, MLVA-3,6,6,2 and MLVA-4,5,7,2, were constantly present and occasionally joined by less abundant, short-lived genotypes, which were detected mostly, but not exclusively, during epidemics. We also noticed a switch in abundance from MLVA-3,5,6,2 and MLVA-3,6,6,2, which dominated in the first epidemic (77.0%; 97/126), to MLVA-4,5,7,2 (71.6%; 428/598), which dominated in the second. Similar to this finding, the dominant P1 type also shifted from type 2 to type 1, although a complete P1 type shift was not observed, since both types remained in circulation. MR was detected in 0.8% (7/872) of M. pneumoniae isolates. Our results seem to suggest that MR remains sporadic in Slovenia at this point in time and that both recent epidemics were polyclonal in nature and, possibly, to some extent, fuelled by the P1 type dominance change.

Clinical Characteristics of Macrolide-Resistant Mycoplasma pneumoniae from Children in Jeju.

Mycoplasma pneumoniae is the major pathogen of community-acquired pneumonia in children. The prevalence of macrolide-resistant M. pneumoniae (MRMP) is important owing to the limited alternative therapies for children. We analyzed 111 M. pneumoniae obtained from 107 children admitted for lower respiratory tract infection at Jeju National University Hospital between 2010 and 2015. Macrolide resistance of M. pneumoniae was searched for using polymerase chain reaction (PCR) and sequencing. Of 107 clinical M. pneumoniae, 11 (10.3%) carried macrolide resistance mutations in the 23S rRNA gene. All macrolide resistance mutations were A2063G transitions. We found an acquired A2063G mutation of M. pneumoniae from a patient during macrolide treatment. Patients' characteristics and clinical severity did not differ between those with MRMP and macrolide-sensitive M. pneumoniae, with the exception of frequent pleural effusion in the MRMP group. The prevalence of MRMP (10.3%) in Jeju Island was relatively lower than those of surrounding countries in East Asia. Previous antimicrobial usage and timing of diagnostic test should be considered when determining of macrolide resistance of M. pneumoniae.

Macrolide-Resistant Mycoplasma pneumoniae Infection, Japan, 2008-2015.

We evaluated isolates obtained from children with Mycoplasma pneumoniae infection throughout Japan during 2008-2015. The highest prevalence of macrolide-resistant M. pneumoniae was 81.6% in 2012, followed by 59.3% in 2014 and 43.6% in 2015. The prevalence of macrolide-resistant M. pneumoniae among children in Japan has decreased.

Emergence of Macrolide-Resistant Mycoplasma pneumoniae in Hong Kong Is Linked to Increasing Macrolide Resistance in Multilocus Variable-Number Tandem-Repeat Analysis Type 4-5-7-2.

Macrolide-resistant Mycoplasma pneumoniae (MRMP) is rapidly emerging in Asia, but information on the temporal relationship between the increase in macrolide resistance and changes in strain types is scarce. Between 2011 and 2014, M. pneumoniae infection was diagnosed by PCR as part of routine care in a health care region in Hong Kong. Testing was initiated by clinicians, mainly in patients with suspected M. pneumoniae pneumonia. Specimens positive for M. pneumoniae were retrospectively investigated by macrolide resistance genotyping and a four-locus (Mpn13 to -16) multilocus variable-number tandem-repeat analysis (MLVA) scheme. The overall percentage of M. pneumoniae-positive specimens was 17.9%, with annual rates ranging from 9.8% to 27.2%. The prevalence of MRMP had rapidly increased from 13.6% in 2011 to 30.7% in 2012, 36.6% in 2013, and 47.1% in 2014 (P = 0.038). Two major MLVA types, 4-5-7-2 and 3-5-6-2, accounted for 75% to 85% of the infections each year. MLVA types 4-5-7-2 and 3-5-6-2 predominated among macrolide-resistant and macrolide-sensitive groups, respectively. The increase in MRMP was mainly caused by increasing macrolide resistance in the prevalent MLVA type 4-5-7-2, changing from 25.0% in 2011 to 59.1% in 2012, to 89.7% in 2013, and to 100% in 2014 (P < 0.001). In conclusion, increasing MRMP in Hong Kong was linked to a single MLVA type, which was both prevalent and increasingly resistant to macrolides.

Characteristics of Mycoplasma pneumoniae infection identified on culture in a pediatric clinic.

BACKGROUND: The appropriate choice of antibiotics against Mycoplasma pneumoniae infection has become difficult, as the prevalence of macrolide-resistant M. pneumoniae has increased. METHODS: Throat swab specimens were collected from children with clinically suspected M. pneumoniae infection while visiting an outpatient clinic. Cultures for M. pneumoniae were done, and all isolates were sequenced for the presence of a mutation in 23S rRNA. RESULTS: Of the 80 specimens collected between February 2012 and March 2013, 27 (34%) were positive for M. pneumoniae on culture. Macrolide-resistant mutation was detected in 24 isolates (89%): 23 isolates had an A2063G transition, and one had a C2617G mutation. Both the median age and the prevalence of pneumonia were significantly higher in M. pneumoniae-positive than in M. pneumoniae-negative children (median, 7 years vs 4 years; 88.9% vs 60.4%, respectively). The percentage of serum samples with particle agglutination titer ≥ 1:160 was 69.6% in M. pneumoniae-positive cases and 17.6% in M. pneumoniae-negative cases when the serum was collected ≥ 4 days after the onset of fever. Defervescence within 72 h after the initiation of macrolides never occurred in M. pneumoniae-positive children and also did not occur in 54% of M. pneumoniae-negative children. Switching to either minocycline or tosufloxacin resulted in fever resolution within 48 h in M. pneumoniae-positive children. CONCLUSIONS: The described clinical and laboratory characteristics of M. pneumoniae infection may be useful in guiding appropriate treatment in an outpatient clinic.

Mycoplasma pneumoniae in children: carriage, pathogenesis, and antibiotic resistance.

PURPOSE OF REVIEW: Both the diagnosis and treatment of Mycoplasma pneumoniae infections in children are currently facing two main challenges: a relatively high carriage in asymptomatic children, and a worldwide increase in macrolide-resistant M. pneumoniae (MRMP). This review focuses on the scientific and clinical implications of these crucial issues. RECENT FINDINGS: Recent studies have indicated that the prevalence of M. pneumoniae in the upper respiratory tract is similar among asymptomatic, healthy children and children with a symptomatic respiratory tract infection, and that current diagnostic procedures for M. pneumoniae are unable to differentiate between bacterial carriage and infection. It is therefore possible that the burden of M. pneumoniae-associated disease is overestimated. Another phenomenon that has an important impact on the treatment of M. pneumoniae infections is the rapid worldwide emergence of MRMP isolates. SUMMARY: The current diagnostic procedures for M. pneumoniae cannot discern between bacterial carriage and infection in a clinically relevant time frame. It is therefore imperative that these procedures be modified such as to unambiguously detect symptomatic M. pneumoniae infections. Moreover, the emergence of MRMP necessitates the application of methods to detect macrolide resistance as well as the implementation of restrictive policies regarding the use of macrolides.

Characterization of macrolide resistance of Mycoplasma pneumoniae in children in Shenzhen, China.

Macrolide-resistant Mycoplasma pneumoniae (MR-M. pneumoniae) was isolated from clinical specimens in Shenzhen, China from November 2010 to July 2011. A comparative study was conducted to determine whether macrolides are effective in treating patients infected with MR-M. pneumoniae. Of 57 M. pneumoniae strains, 36 harbored point mutations on A2063G in the 23S ribosomal RNA gene. A total of 36 (63%) strains were classified as MR-M. pneumonia and 21 (37%) as macrolide-susceptible M. pneumoniae (MS-M. pneumoniae). The clinical courses of MR-M. pneumoniae-infected patients (MR patients) treated with macrolides were compared with those of MS-M. pneumoniae-infected patients (MS patients). The patient demographics (sex, age), most laboratory findings, and diagnosis did not show significant differences between the two groups. The MR patients had higher mean total febrile days compared with MS patients (6.56 ± 6.17 days vs. 3.57 ± 3.80 days, P = 0.05). The MR patients were more likely to be have levels of high-sensitivity C-reactive protein than MS patients (42% (15/36) vs. 14% (3/21), P = 0.03). Although the febrile period was prolonged in MR patients treated with macrolides, the fever resolved even when the initial prescription was unchanged. Therefore, these results suggest that macrolides are less effective in MR patients than in MS patients.

Rapid effectiveness of minocycline or doxycycline against macrolide-resistant Mycoplasma pneumoniae infection in a 2011 outbreak among Japanese children.

BACKGROUND: Mycoplasma pneumoniae is a major pathogen causing community-acquired pneumonia in children and young adults. Outbreaks typically occur at intervals of several years. In 2011, a widespread outbreak was associated with macrolide-resistant M. pneumoniae (MRMP) in Japanese children, often those of school age. METHODS: Two hundred fifty-eight children were diagnosed with M. pneumoniae-associated pneumonia based on chest radiography, real-time polymerase chain reaction (PCR), and antibody titers between January and December 2011. Mycoplasma pneumoniae cultures obtained from nasopharyngeal samples using appropriate broth were subjected to real-time PCR, by which decreases in M. pneumoniae in patients treated with minocycline (MIN), doxycycline (DOX), or tosufloxacin (TFX) were calculated. Mutations of the 23S ribosomal RNA gene that confer high resistance to macrolides in M. pneumoniae were identified by DNA sequencing. RESULTS: Among 202 M. pneumoniae isolates from M. pneumoniae-associated pneumonia patients, 176 (87.1%) were MRMP. Macrolide-resistant M. pneumoniae infection was significantly related to school age (P < .01) and initial administration of macrolides (P < .01). Minocycline or DOX (n = 125) or TFX or levofloxacin (n = 15) was used for definitive treatment of MRMP patients. Minocycline or DOX was significantly more effective than TFX (P ≤ .05) in achieving defervescence within 24 hours and in decreasing numbers of M. pneumoniae DNA copies 3 days after initiation. CONCLUSIONS: Macrolides are inappropriate as first-choice agents against MRMP in terms of shortening the clinical course and decreasing M. pneumoniae. Control and prevention of MRMP outbreaks in children require early decreases in M. pneumoniae as well as improvement of clinical findings.

Multilocus variable-number tandem-repeat analysis-confirmed emergence of a macrolide resistance-associated mutation in Mycoplasma pneumoniae during macrolide therapy for interstitial pneumonia in an immunocompromised child.

A child with Job's syndrome was treated for pneumonia due to Mycoplasma pneumoniae. A mixed population of wild-type bacteria and an A2059G mutant was detected during josamycin treatment failure. The same multilocus variable-number tandem-repeat analysis (MLVA) type (MLVA type I) was isolated before and after treatment failure. The child recovered after ciprofloxacin treatment.

Mycoplasma pneumoniae-associated mucositis with minimal skin manifestations.

Mycoplasma pneumoniae-associated mucositis is a rarely described complication of M. pneumoniae infection presenting with ocular, oral, and genital involvement but without the typical skin lesions seen in Stevens-Johnson syndrome. A 27-year-old man with a past history of asthma presented at the emergency room with a 1-week history of cough (initially non-productive but subsequently associated with non-bloody mucopurulent sputum), fever, myalgias, headache, and progressive dyspnea. Two days before admission he had commenced amoxicillin/clavulanic acid with no improvement. The patient reported bilateral conjunctival injection and hemorrhagic ulcers on the lips commencing the day prior to admission. Physical examination revealed fever (39 degrees C), bilateral exudative conjunctivitis, painful hemorrhagic ulcers on the lips, tongue, and oral mucosa, small scrotal erosions, erythema of the penile meatus, and small erythematous bullae on the dorsum of each hand; subsequently, the patient developed bullae at the venipuncture site on his right arm. Laboratory tests revealed positive IgM serology for M. pneumoniae, with titer elevation. The patient was successfully treated with levofloxacin and prednisolone. Our case appears to be the first adult patient described with M. pneumoniae-associated mucositis, which has previously been reported only in pediatric patients. This is also the first reported instance of a case of M. pneumoniae-associated mucositis treated with levofloxacin and prednisolone. M. pneumoniae infection should be considered in all cases of mucositis, and treatment of this condition with levofloxacin and prednisolone seems to be effective.

Infecciones respiratorias agudas bajas en niños: estudio etiológico prospectivo / Lower respiratory tract infections in children: a prospective etiological study

Background: Lower respiratory tract infection (LRTI) is a serious cause of morbidity and admission among children. The aim of the present investigation was to determine the etiology of severe LRTI in hospitalized children by several laboratory methods in a systematic way. Methods: A 2-year prospective study. Results: A potential causative agent was detected in 155(68 percent) of the 229 patients. A viral infection was identified in 60 percent, 15 percent had bacterial infection and 4 percent had evidence of concomitant viral-bacterial infection. Virus, with the predominance of respiratory syncytial virus (RSV) was the most common agent in children younger than 24 month. Mycoplasma pneumoniae and Streptococcus pneumoniae were the most important bacteria. Conclusions: The possible causative agent on childhood LRTI could be detected in most cases. The data confirm the importance of virus especially RSV in the LRTI in hospitalized children.

Resumen: Las infecciones respiratorias agudas bajas (IRAb) son causa importante de morbilidad y de hospitalización en los niños. El objetivo de esta investigación fue determinar la etiología de IRAb grave de niños hospitalizados por varios métodos diagnósticos en forma protocolizada. Método: Estudio prospectivo en dos años consecutivos. Resultados: Un posible agente causal fue detectado en 155 (68 por ciento) de 229 pacientes: Infección viral fue identificada en 60 por ciento, bacteriana: 15 por ciento y mixta: 4 por ciento. Virus, principalmente virus respiratorio sincicial (VRS) fue el agente etiológico más frecuente en menores de 24 meses. Mycoplasma pneumoniae y Streptococcus pneumoniae fueron las principales bacterias aisladas. Conclusiones: Un posible agente causal de la IRAb en niños pudo ser identificado en la mayoría de los casos. Los datos confirman la importancia de los virus, especialmente VRS, en la IRAb en niños hospitalizados.

Uso de inmunoglobulina intravenosa en el tratamiento de necrólisis epidérmica tóxica y síndrome de Stevens-Johnson / Use of intravenous immunoglobulin in toxic epidermal necrolysis and Stevens-Johnson syndrome

La necrólisis epidérmica tóxica (NET) y el síndrome de Stevens-Johnson (SSJ) se describen como variantes de una misma enfermedad con diferente severidad y constituyen las reacciones cutáneas más frecuentes en niños con una considerable morbilidad. Varias comunicaciones apoyan el uso de la inmunoglobulina intravenosa (IGIV) para el tratamiento de tales entidades. Nosotros presentamos el caso de 2 pacientes, uno con NET y uno con SSJ en quienes se utilizó inmunoglobulina con resultados exitosos. Además hacemos una revisión de la evolución de 13 pacientes con NET y SSJ en los últimos 10 años en el Hospital Infantil de México en quienes se utilizó tratamiento convencional

Toxic epidermal necrolysis and Stevens-Johnson syndrome are described as variants of the same disease with distinct severity and constitute the most frequent cutaneous reactions in children, causing considerable morbidity. Several reports support the use of intravenous immunoglobulin therapy in these entities. We report the cases of two patients, one with toxic epidermal necrolysis and the other with Stevens-Johnson syndrome, in whom immunoglobulin treatment was successfully used. We also reviewed the outcomes of 13 patients with toxic epidermal necrolysis and Stevens-Johnson syndrome in the previous 10 years in the Hospital Infantil de Mexico, in whom conventional treatment was used

Distribution of Mycoplasma pneumoniae and Mycoplasma salivarium in the synovial fluid of arthritis patients.

By use of a very sensitive nested PCR method targeting part of the strongly conserved mycoplasmal 16S RNA genes, Mycoplasma pneumoniae was found in the synovial fluid of 19/24 (79%) of rheumatoid arthritis patients, 6/6 (100%) of patients with nonrheumatoid inflammatory arthritis, and 8/10 (80%) of osteoarthritis patients attending the rheumatology clinic for drainage of joint effusions. It was not found in the synovial exudates of 13 people attending the orthopedic clinic with traumatic knee injuries or undergoing surgery for knee replacement. However, M. pneumoniae was detected in 2/4 synovial biopsy specimens from orthopedic patients with traumatic knee injuries. M. pneumoniae was associated with the increased synovial fluids found in arthritic flares but was not found in the synovial fluids of trauma patients. Mycoplasma salivarium occurred sporadically. Mycoplasma fermentans had previously been isolated from patients with inflammatory cellular infiltrates, such as rheumatoid arthritis, but it was not detected for osteoarthritic patients from either clinic. It is possible that these organisms may contribute to chronic inflammation within the joints.

[Effect of Huchang Qingfei concentrated pellets on E-cadherin expression in lung tissue of mice infected with Mycoplasma pneumoniae].

OBJECTIVE: To investigate the effects of Huchang Qingfei concentrated pellets on the expression of E-cadherin (E-cd) in the lung tissue from mice infected with Mycoplasma pneumoniae (MP). METHOD: A mice model of Mycoplasmal pneumonia (MPP) was developed by repeatedly intranasal infectious route. Transmission electronic microscope (TEM) and immunohistochemistry stain were performed to observe the pathological changes and expression of E-cd in lung tissues. RESULT: Under TEM it was found that the cellular membrane was ruptured, mitochondria was denatured, crista was broken in the pulmonary cells of the model group; the all above parameters in Huchang medicated group were improved obviously. The immunohistochemistry test showed that strong positive brown stain of E-cd expression was found in the pulmonary epithelial cell membrane and bronchial periphery in the model group, however, in the medicated group, the E-cd expression level in the cellular membrane was decreased and the expression ratio was dropped significantly as compared with the model controls. CONCLUSION: Huchang Qingfei concentrated pellets can inhibit the overexpression of E-cd in the lung tissue of mice with MP-infection, which may be helpful for prevention and treatment of pulmonary injury caused by MPP.