Publications by authors named "Mitsuo Narita"

36 Publications

Point-of-care molecular diagnosis of Mycoplasma pneumoniae including macrolide sensitivity using quenching probe polymerase chain reaction.

PLoS One 2021 14;16(10):e0258694. Epub 2021 Oct 14.

Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan.

Objectives: Macrolides are generally considered to be the drugs of choice for treatment of patients with Mycoplasma pneumoniae infection. However, macrolide-resistant M. pneumoniae has been emerging since about 2000. The Smart Gene® system (MIZUHO MEDY Co., Ltd., Tosu, Japan) is a novel fully automated system for detection of pathogens using the method of quantitative polymerase chain reaction (qPCR) with QProbe (QProbe PCR). The entire procedure is completed within 50 min and the size of the instrument is small (15 x 34 x 30 cm). The purpose of this study was to evaluate the usefulness of the Smart Gene® system for detection of M. pneumoniae and detection of a point mutation at domain V of the 23S rRNA gene of M. pneumoniae.

Materials: Pharyngeal swab samples were collected from 154 patients who were suspected of having respiratory tract infections associated with M. pneumoniae.

Results: Compared with the results of qPCR, the sensitivity and specificity of the Smart Gene® system were 98.7% (78/79) and 100.0% (75/75), respectively. A point mutation at domain V of the 23S rRNA gene was detected from 7 (9.0%) of 78 M. pneumoniae-positive samples by the Smart Gene® system and these results were confirmed by direct sequencing. The minimum inhibitory concentrations of clarithromycin among the 5 isolates of M. pneumoniae with a point mutation at domain V of the 23S rRNA gene were >64 μg/ml and those among the 33 isolates without a mutation in the 23S rRNA gene were <0.0625 μg/ml.

Conclusion: The Smart Gene® system is a rapid and accurate assay for detection of the existence of M. pneumoniae and a point mutation at domain V of the 23S rRNA gene of M. pneumoniae at the same time. The Smart Gene® system is suitable for point-of-care testing in both hospital and outpatient settings.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0258694PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8516298PMC
November 2021

gene of isolated from 2016 to 2019 and relationship between genotyping and macrolide resistance in Hokkaido, Japan.

J Med Microbiol 2021 Jun;70(6)

Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan.

We characterized 515 specimens in Hokkaido. In 2013 and 2014, the gene type 1 strain, mostly macrolide-resistant, was dominant and the prevalence of macrolide resistance was over 50 %. After 2017, the gene type 2 lineage, mostly macrolide-sensitive, increased and the prevalence of macrolide resistance became 31.0 % in 2017, 5.3 % in 2018 and 16.3 % in 2019.
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http://dx.doi.org/10.1099/jmm.0.001365DOI Listing
June 2021

Effect of Serum SPARC Levels on Survival in Patients with Digestive Tract Cancer: A Post Hoc Analysis of the AMATERASU Randomized Clinical Trial.

Cancers (Basel) 2020 Jun 4;12(6). Epub 2020 Jun 4.

Division of Molecular Epidemiology, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-Ku, Tokyo 105-8461, Japan.

Observational studies suggest that physical activity may improve, whereas sarcopenia may worsen the survival of cancer patients. It has been suggested that secreted protein acidic and rich in cysteine (SPARC), one of the myokines that is secreted into the bloodstream by muscle contraction, has tumor-suppressive effects. Based on the hypothesis that serum SPARC level may be a potential prognostic biomarker, a post hoc analysis of the AMATERASU randomized, double-blind, placebo-controlled trial of postoperative oral vitamin D supplementation (2000 IU/day) in patients with stage I-III digestive tract cancer from the esophagus to the rectum (UMIN000001977) was conducted with the aim of exploring the association between serum SPARC levels after operation and survival. On multivariate analyses adjusting serum 25-hydroxyvitamin D, vitamin D supplementation, sarcopenia, body mass index, age, sex, cancer loci, stage, and adjuvant chemotherapy, patients with SPARC levels lower than the median level had a significantly higher risk for death than those with higher levels (hazard ratio, 2.25; 95% confidence interval, 1.25-4.05; = 0.007), whereas there were no significant associations with other outcomes including recurrence. However, on the same multivariate analyses, sarcopenia was not a risk factor for death and/or relapse. These results suggest that serum SPARC levels may be a potential biomarker for death but not cancer relapse.
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http://dx.doi.org/10.3390/cancers12061465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352842PMC
June 2020

Common carotid arteritis and polymyalgia with Mycoplasma pneumoniae infection.

J Infect Chemother 2019 Apr 28;25(4):281-284. Epub 2018 Sep 28.

Department of Pediatrics, Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan. Electronic address:

A few pediatric cases with brain vasculitis most frequently affecting the middle cerebral artery have been reported in association with Mycoplasma pneumoniae infection, but involvement of the common carotid artery (CCA) before the bifurcation has not been reported to date. We report herein a case of 10-year-old boy with common carotid arteritis and polymyalgia associated with Mycoplasma pneumoniae infection. His fever and cough began 2 weeks before, and his right upper and lower extremity pains began 2 days before admission. He had initially been treated with clarithromycin followed by tosufloxacin, but his symptoms persisted. His M. pneumonia-specific antibody titer was high on admission (1:10240 by particle agglutination method) and the gene of M. pneumoniae was detected in a throat swab specimen by the loop-mediated isothermal amplification method with initial high levels of serum interleukin-8, tumor necrosis factor-α, and interleukin-18 along with elevated blood levels of complements. On the 5th day of hospitalization, vascular echograms of the extremities and neck showed increasing intima-media thickness of bilateral CCAs without stenosis and/or thrombosis and T2-weighted with lipid suppression magnetic resonance imaging of the neck showed high signal intensity of bilateral CCA walls. Coagulation studies were unremarkable and no autoantibodies were detected as far as tested. He was successfully treated by intravenous administration of prednisolone and was stable without any neurological sequelae 17 months after the onset without medication. His particle agglutination titer decreased to 1:5120, and serum interleukin-8, tumor necrosis factor-α, interleukin-18, and complement levels returned to normal.
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http://dx.doi.org/10.1016/j.jiac.2018.09.001DOI Listing
April 2019

Management of maternal anaphylaxis in pregnancy: a case report.

Acute Med Surg 2017 04 10;4(2):202-204. Epub 2016 Nov 10.

Department of General Medicine Sapporo Tokushukai Hospital Sapporo Hokkaido Japan.

Case: A 26-year-old woman (gravida 2, para 1) at 25 weeks' gestation was brought to the emergency department because of anaphylactic symptoms. She reported eating Japanese soba and developed symptoms of dyspnea, generalized itchy rash, abdominal pain, and severe uterine contractions within 15-30 min of eating. She was immediately treated by normal saline infusion, two injections of epinephrine (intramuscularly), and a nebulized short-acting β-receptor agonist, followed by H-antihistamine and methylprednisolone. Obstetrical management was undertaken by an obstetrician.

Outcome: The patient recovered rapidly without a biphasic reaction of anaphylaxis. After 11 weeks, a healthy, neurologically intact baby was born.

Conclusion: Management of anaphylaxis in pregnant patients is basically the same of that in non-pregnant ones. Treatment should commence immediately to prevent further development of the anaphylaxis reaction and fetal neurological deficiency.
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http://dx.doi.org/10.1002/ams2.238DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5667276PMC
April 2017

Histological findings in severe Mycoplasma pneumoniae pneumonia.

J Med Microbiol 2017 May 18;66(5):690-692. Epub 2017 May 18.

Department of Internal Medicine 1, Kawasaki Medical School, Okayama, Japan.

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http://dx.doi.org/10.1099/jmm.0.000501DOI Listing
May 2017

Classification of Extrapulmonary Manifestations Due to Mycoplasma pneumoniae Infection on the Basis of Possible Pathogenesis.

Authors:
Mitsuo Narita

Front Microbiol 2016 28;7:23. Epub 2016 Jan 28.

Department of Pediatrics, Sapporo Tokushukai Hospital Sapporo, Japan.

The list of extrapulmonary manifestations due to Mycoplasma pneumoniae infection can be classified according to the following three possible mechanisms derived from the established biological activity of M. pneumoniae; (1) a direct type in which the bacterium is present at the site of inflammation and local inflammatory cytokines induced by the bacterium play an important role (2) an indirect type in which the bacterium is not present at the site of inflammation and immune modulations, such as autoimmunity or formation of immune complexes, play an important role, and (3) a vascular occlusion type in which obstruction of blood flow induced either directly or indirectly by the bacterium plays an important role. Recent studies concerning extrapulmonary manifestations have prompted the author to upgrade the list, including cardiac and aortic thrombi as cardiovascular manifestations; erythema nodosum, cutaneous leukocytoclastic vasculitis, and subcorneal pustular dermatosis as dermatological manifestations; acute cerebellar ataxia, opsoclonus-myoclonus syndrome, and thalamic necrosis as neurological manifestations; pulmonary embolism as a respiratory system manifestation; and renal artery embolism as a urogenital tract manifestation. Continuing nosological confusion on M. pneumoniae-induced mucositis (without skin lesions), which may be called M. pneumoniae-associated mucositis or M. pneumoniae-induced rash and mucositis separately from Stevens-Johnson syndrome, is argued in the dermatological manifestations. Serological methods are recommended for diagnosis because pneumonia or respiratory symptoms are often minimal or even absent in extrapulmonary manifestations due to M. pneumoniae infection. Concomitant use of immunomodulators, such as corticosteroids or immunoglobulins with antibiotics effective against M. pneumoniae, can be considered as treatment modalities for most severe cases, such as encephalitis. Further studies would be necessary to construct a comprehensive therapeutic strategy, covering microbiology (antibiotics), immunology (immunomodulators), and hematology (anticoagulants). The possible influence of the emergence of macrolide-resistant M. pneumoniae on extrapulmonary manifestations, which can be considered of limited clinical threat in Japan where the resistant rate has currently decreased, is discussed on the basis of unique biological characteristics of M. pneumoniae, the smallest self-replicating organism.
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http://dx.doi.org/10.3389/fmicb.2016.00023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4729911PMC
February 2016

Extra-pulmonary manifestations associated with Mycoplasma pneumoniae pneumonia in adults.

Eur J Intern Med 2016 Apr 24;29:e9-e10. Epub 2015 Nov 24.

Department of Pediatrics, Sapporo Tokushukai Hospital, Sapporo, Japan.

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http://dx.doi.org/10.1016/j.ejim.2015.11.011DOI Listing
April 2016

[Diagnosis, treatment and prevention of infectious diseases. Topics: I. Countermeasures against epidemic infectious diseases: 4. Macrolide-resistant Mycoplasma pneumoniae].

Authors:
Mitsuo Narita

Nihon Naika Gakkai Zasshi 2013 Nov;102(11):2823-30

Department of Pediatrics, Sapporo Tokushukai Hospital, Japan.

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http://dx.doi.org/10.2169/naika.102.2823DOI Listing
November 2013

Gene and cytokine profile analysis of macrolide-resistant Mycoplasma pneumoniae infection in Fukuoka, Japan.

BMC Infect Dis 2013 Dec 16;13:591. Epub 2013 Dec 16.

Matsuda Children's Clinic, Fukuoka, Japan.

Background: Recent epidemiologic data suggest that the prevalence of macrolide resistant Mycoplasma pneumoniae (MR-M. pneumoniae) is increasing rapidly worldwide. This study assessed the present status of M. pneumoniae infection in Japan and clinical end-points to distinguish children with MR-M. pneumoniae.

Methods: During an outbreak of M. pneumoniae infections in Fukuoka, Japan in 2010-11, a total of 105 children with clinically suspected M. pneumoniae infection were enrolled. M. pneumoniae was analyzed for macrolide resistance in domain V of the 23S rRNA gene. Sixty -five patients with PCR positive for M. pneumoniae were analyzed with regard to clinical symptoms, efficacy of several antimicrobial agents and several laboratory data.

Results: Causative pathogens were detected in 81.0% (85 of 105) and M. pneumoniae was identified 61.9% (65 of 105). The resistance rate of M. pneumoniae was 89.2% (58 of 65) in this general pediatric outpatient setting. Patients infected with MR-M. pneumoniae showed longer times to resolution of fever and required frequent changes of the initially prescribed macrolide to another antimicrobial agent. We observed three different genotypes of M. pneumoniae including the rarely reported A2063T mutation (A2063G: 31 strains, A2063T: 27 strains, no mutation: 7 strains). Drug susceptibility testing showed different antimicrobial susceptibility profiles for each genotype. Serum IFN-gamma, IL-6 and IP-10 levels were higher in patients with MR-genotypes than in those infected with no-mutation strains (p < 0.001).

Conclusions: Macrolide resistance is more common than previously thought and a small epidemic of rarely reported A2063T mutation was observed in Fukuoka, Japan. Furthermore our results reveal the possibility that levels of certain inflammatory cytokines may be a candidate to predict MR-M.pneumoniae infection.
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http://dx.doi.org/10.1186/1471-2334-13-591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883477PMC
December 2013

Late increase of interleukin-18 levels in blood during Mycoplasma pneumoniae pneumonia.

Cytokine 2012 Jul 5;59(1):18-9. Epub 2012 May 5.

To the Editor, we read with great interest the article by Chung et al. which appeared recently in the journal. In that paper the authors reported that the decreased IL-18 response in severe pneumonia group vs. non-severe group was observed regardless of asthma status of the patients, whose findings were somewhat different from ours on non-asthmatic patients which showed higher serum levels of IL-18 in severe cases of pneumonia than in mild cases in terms of both in children and in adults. In this point, the timing of venous sampling must be an important factor in explaining the discrepant results. Our previous results suggest that the level of IL-18 in blood as a marker of disease severity should cautiously be interpreted considering a timing of sampling; a value of IL-18 in a blood sample which is obtained at the first visit to the hospital does not always represent the highest level of IL-18 because of the fact that the time which elapsed from the onset of illness to the blood sampling may vary among patients. Analyses on sequential samples, therefore, must be necessary to fully understand the perplexing nature of cytokine activation during Mycoplasma pneumoniae infection.
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http://dx.doi.org/10.1016/j.cyto.2012.04.007DOI Listing
July 2012

Rhabdomyolysis associated with antimicrobial drug-resistant Mycoplasma pneumoniae.

Emerg Infect Dis 2012 May;18(5):849-51

Niigata University Medical and Dental Hospital, Niigata, Japan.

We describe a case of rhabdomyolysis in a patient infected with antimicrobial drug-resistant Mycoplasma pneumoniae The patient's acute-phase serum levels of interleukin-18 and tumor necrosis factor-α were high, which suggests a pathogenic role for M. pneumoniae. In an era of increasing antimicrobial drug resistance, a system for rapidly identifying resistant M. pneumoniae would be beneficial.
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http://dx.doi.org/10.3201/eid1805.111149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3358083PMC
May 2012

Complete genome sequence of Mycoplasma pneumoniae type 2a strain 309, isolated in Japan.

J Bacteriol 2012 Mar;194(5):1253-4

Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.

Mycoplasma pneumoniae strain 309, a type 2a (subtype 2 variant) strain of this bacterium, has variations in the P1 protein, which is responsible for attachment of the bacterium to host cells. Here, we report the complete genome sequence of M. pneumoniae strain 309 isolated from a pneumonia patient in Japan.
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http://dx.doi.org/10.1128/JB.06553-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3294768PMC
March 2012

Clinical implications of interleukin-18 levels in pediatric patients with Mycoplasma pneumoniae pneumonia.

J Infect Chemother 2011 Dec 17;17(6):803-6. Epub 2011 Jun 17.

Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medicine and Dental Sciences, Asahimachi, Niigata 951-8510, Japan.

The immunological pathogenesis of Mycoplasma pneumoniae pneumonia is known to involve several cytokines. The serum levels of interleukin-18 (IL-18) were examined using enzyme-linked immunosorbent assay in 23 pediatric patients (median age 6 years; range 4-13 years; 14 girls and 9 boys) with M. pneumoniae pneumonia admitted to our hospital. Serum levels of IL-18 ranged from 22 to 1808 pg/ml with a mean of 543 pg/ml. We started steroid therapy in two cases with IL-18 values greater than 1000 pg/ml without being aware of IL-18 levels. Examination of associations between IL-18 levels determined by enzyme-linked immunosorbent assay and a routine laboratory test showed that levels of lactate dehydrogenase (LDH) and IL-18 were significantly correlated. To determine the appropriateness of steroid administration in M. pneumoniae pneumonia patients, serum LDH should be examined. Patients with elevated levels of LDH are likely to have significantly elevated IL-18 values (≥1000 pg/ml) and thus can be candidates for steroid therapy.
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http://dx.doi.org/10.1007/s10156-011-0265-7DOI Listing
December 2011

Pathogenesis of extrapulmonary manifestations of Mycoplasma pneumoniae infection with special reference to pneumonia.

Authors:
Mitsuo Narita

J Infect Chemother 2010 Jun 27;16(3):162-9. Epub 2010 Feb 27.

Department of Pediatrics, JR Sapporo Hospital, Chuo-ku, Sapporo, Japan.

Although pneumonia has been a hallmark of Mycoplasma pneumoniae infection, it has been revealed that this infection can cause a number of extrapulmonary manifestations in the absence of pneumonia. While the host immune response has been implicated in the pathomechanism of pneumonia, the pathomechanisms of extrapulmonary manifestations remain largely unknown. It is proposed in this review that extrapulmonary manifestations due to M. pneumoniae infection can be classified into three categories; the first is a direct type in which inflammatory cytokines locally induced by lipoproteins contained in the bacterial cell membrane must play a role, the second is an indirect type in which immune modulation such as autoimmunity through cross-reaction between the bacterial cell components and human cells must play a role, and the third is a vascular occlusion type in which vasculitis and/or thrombosis with or without systemic hypercoagulable state induced by the bacterium must play a role. Based on this classification, a literature review was carried out for extrapulmonary manifestations due to M. pneumoniae infection with special reference to pneumonia, including cardiovascular, dermatological, digestive organ, hematological/hematopoietic system, musculoskeletal, sensory organ, and urogenital tract manifestations. Consequently, most extrapulmonary manifestations due to M. pneumoniae infection can be reasonably classified into and explained by one of the three types of pathomechanisms mentioned above. Noticeably in this review, Kawasaki disease and infectious mononucleosis in association with M. pneumoniae infection, which are not unusual in Japan but have seldom been reported from Western countries, are included in the panel of extrapulmonary manifestations due to M. pneumoniae infection.
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http://dx.doi.org/10.1007/s10156-010-0044-xDOI Listing
June 2010

Three familial cases of drug-resistant Mycoplasma pneumoniae infection.

Eur J Pediatr 2010 Jun 8;169(6):721-6. Epub 2009 Nov 8.

Department of Pediatrics, Kamiamakusa General Hospital, 1419-19, Takado, Ryugatake, Kamiamakusa, Kumamoto 866-0202, Japan.

Unlabelled: Mycoplasma pneumoniae infection is believed to result from defective host immune response rather than from direct cell injury by the organism itself. In this context, emergence of drug-resistant M. pneumoniae may provide us with special opportunities to study the pathogenesis from a clinical point of view. In this report, three patients with intrafamilial M. pneumoniae infection are presented. M. pneumoniae was isolated with a Hayflick pleuropneumonia-like organism diphasic medium. Minimal inhibitory concentrations of antibiotics were determined by a broth microdilution method. Polymerase chain reaction and restriction fragment length polymorphism analysis were done to determine point mutation in domain V of the 23S rRNA gene. As a result, all three strains from the three intrafamilial cases had the same drug-resistant point mutation, specifically A-to-G transition at position 2063. However, their clinical courses were quite different; a 6-year-old girl suffered severe pneumonia, a 5-year-old girl had mild pneumonia, and a 3-year-old boy had only a fever of 1-day duration without pneumonia.

Conclusions: Our clinical and laboratory observations strongly support the idea that the host immune maturity, rather than a virulence factor of the organism, is a major determinant factor of disease severity of M. pneumoniae infection and that drug resistance does not necessarily lead to a serious clinical outcome.
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http://dx.doi.org/10.1007/s00431-009-1100-3DOI Listing
June 2010

Pathogenesis of neurologic manifestations of Mycoplasma pneumoniae infection.

Authors:
Mitsuo Narita

Pediatr Neurol 2009 Sep;41(3):159-66

Department of Pediatrics, Sapporo Tetsudo Hospital, N 3 E 1 Chuo-ku, Sapporo 060-0033, Japan.

Mycoplasma pneumoniae has been associated with various neurologic manifestations, but exactly how the organism can cause such a wide variety of diseases is a long-standing mystery. In this respect, although pneumonia has been considered the hallmark of Mycoplasma pneumoniae infection, emerging accumulations of data have revealed that the infection can cause a number of extrapulmonary manifestations even in the absence of pneumonia. The importance of host immune response in the pathomechanism of pneumonia has been established, but the pathomechanisms of extrapulmonary manifestations remain largely unknown. For this review, extrapulmonary manifestations due to M. pneumoniae infection were classified into three categories: a direct type, in which locally induced cytokines must play a role; an indirect type, in which immune modulation such as autoimmunity must play a role; and a vascular occlusion type, in which vasculitis or thrombosis (either or both, and with or without systemic hypercoagulable state) must play a role. This classification was then applied within a literature review for neurologic manifestations. Most neurologic manifestations due to M. pneumoniae infection could be reasonably classified into and explained by one of the three types of pathomechanisms.
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http://dx.doi.org/10.1016/j.pediatrneurol.2009.04.012DOI Listing
September 2009

Genotyping analysis of Mycoplasma pneumoniae clinical strains in Japan between 1995 and 2005: type shift phenomenon of M. pneumoniae clinical strains.

J Med Microbiol 2008 Apr;57(Pt 4):469-475

Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan.

Mycoplasma pneumoniae clinical isolates obtained between 1995 and 2005 were examined to determine the prevalent genotype. One hundred and twenty-seven strains isolated from bronchitis and pneumonia patients were genotyped by a PCR-RFLP method based on nucleotide sequence polymorphisms of the p1 gene, which encodes the major adhesin protein. The typing results established that 66 of the isolates were group I strains, 45 were group II strains and 16 were group II variants. Analysis of the annual occurrence of these isolates showed a predominance of group II strains between 1995 and 2001 (n=37). No group I strain was found during this period. However, group I strains appeared in the isolates from 2002 (2/5 isolates, 40 %) and increased in specimens taken after 2003, thereby constituting a large proportion of the isolates. In 2004 and 2005, no group II strains were found among the isolates (n=49), although there were nine group II variants. Throat swabs and sputum samples obtained from patients with respiratory infections between 1997 and 2005 were also analysed by PCR-RFLP or a new nested PCR to detect the p1 gene DNA. Typing analysis of these p1 gene DNAs also showed that the group I p1 gene was not present in specimens taken before 2000, but was present and dominant in specimens taken after 2001. These results indicate that, in Japan, the prevalent type of M. pneumoniae changed from a group II strain to a group I strain around 2002.
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http://dx.doi.org/10.1099/jmm.0.47634-0DOI Listing
April 2008

Mycoplasma pneumoniae encephalitis and cytokines.

Authors:
Mitsuo Narita

Pediatrics 2008 Jan;121(1):224; author reply 224-5

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http://dx.doi.org/10.1542/peds.2007-2675DOI Listing
January 2008

[Utility and limitation of the rapid IgM antibody detection test for the diagnosis of Mycoplasma pneumoniae infection].

Authors:
Mitsuo Narita

Kansenshogaku Zasshi 2007 Mar;81(2):149-54

Department of Pediatrics, Sapporo Tetsudo Hospital.

I evaluated performance of the Mycoplasma pneumoniae-specific IgM antibody rapid detection test (ImmunoCard Mycoplasma, IC, Meridian, USA) and compared it to the particle agglutination (PA) test and ELISA tests (Mycoplasma pneumoniae IgG, IgA, IgM ELISA medac, Medac Diagnostika, Germany). Serum samples numbering 112 were obtained from 70 pediatric patients (< 16 years old) with M. pneumoniae infection diagnosed by a PA test (four-fold or greater rise by paired serum samples or > or = 1:640 by a single serum sample). Of these, 82 samples (73.2%) were positive in IC and 91 (81.3%) positive in ELISA IgM tests. Specifically, for samples obtained within 7 days following the onset of fever, 6 of the 14 positive in the ELISA IgM test were negative in IC and 4 of the 18 samples negative in the ELISA IgM test were positive in IC. I ascribed this difference to the difference in antigens used in each test. In the analysis of sequential serum samples from 2 patients with M. pneumoniae pneumonia, IC was still positive in 248- and 527-day samples for which a PA test and the ELISA IgM and IgG tests indicated no acute infection. Nine (36.0%) of 25 serum samples obtained from apparently healthy adult volunteers were positive in IC. Of the 9 IC-positive cases, ELISA tests suggested possible recent infection at most in 3 cases, while the remaining 6 cases had no evidence of acute infection. In conclusion, although IC is sufficiently sensitive as a rapid screening test for detecting M. pneumoniae-specific IgM antibody, a positive result in the test does not always indicate acute infection by this organism. To ensure accurate diagnosis of M. pneumoniae infection, paired serum samples are thus required for conventional methodologies.
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http://dx.doi.org/10.11150/kansenshogakuzasshi1970.81.149DOI Listing
March 2007

Roles of N-linked glycans in the recognition of microbial lipopeptides and lipoproteins by TLR2.

Cell Microbiol 2006 Jul;8(7):1199-209

Laboratory of Oral Molecular Microbiology, Department of Oral Pathobiological Science, Hokkaido University Graduate School of Dental Medicine, Nishi 7, Kita 13, Kita-ku, Sapporo 060-8586, Japan.

Details of roles of carbohydrates attached to Toll-like receptors (TLRs) in the recognition of pathogen-associated molecular patterns and in the formation of the functional receptor complex still remain unknown. This study was designed to determine whether the glycans linked at Asn114, Asn199, Asn414 and Asn442 residues of TLR2 ectodomain were involved in the recognition of diacylated lipopeptide and lipoprotein. Single and multiple mutants were transfected into human embryonic kidney (HEK) 293 cells together with a NF-kappaB luciferase reporter plasmid. All of these mutants were expressed on the surface. SDS-PAGE of the transfectants demonstrated that these mutants migrated lower than wild-type TLR2 and their molecular masses decreased as the number of mutated Asn residues increased. TLR2(N114A), TLR2(N199A) and TLR2(N414A) as well as wild-type TLR2 induced NF-kappaB activation when stimulated with these ligands, whereas TLR2(N442A) failed to induce NF-kappaB activation. All of triple and quadruple mutants failed to induce NF-kappaB activation, but were associated with both wild-type TLR2 and TLR6 in the transfectants. TLR2(N114A,N199A), TLR2(N114A,N414A) and, to a lesser extent, TLR2(N114A,N442A), in which two N-linked glycans are speculated to be exposed to the concave surface of TLR2 solenoid, not only induce NF-kappaB activation but also are associated with wild-type TLR2 and TLR6. These results suggest that the glycan at Asn442 and at least two N-linked glycans speculated to be exposed to the concave surface of TLR2 solenoid are involved in the recognition of ligands by TLR2 and/or in formation or maturation of a functional TLR2 receptor complex.
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http://dx.doi.org/10.1111/j.1462-5822.2006.00702.xDOI Listing
July 2006

Comparison of PCR for sputum samples obtained by induced cough and serological tests for diagnosis of Mycoplasma pneumoniae infection in children.

Clin Vaccine Immunol 2006 Jun;13(6):708-10

Department of Pediatrics, Saitama Medical School, Morohongo 38, Moroyama, Iruma, 350-0495 Japan.

Passive agglutination (PA) and immunoglobulin M (IgM), IgA, and IgG enzyme-linked immunosorbent assays (ELISAs) for the diagnosis of Mycoplasma pneumoniae were compared with PCR testing of sputum samples obtained from children with lower respiratory tract infections. The sensitivity and specificity of PA were 80.3% and 92.3% at a titer of 1:80. ELISA was found to be less sensitive than PA.
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http://dx.doi.org/10.1128/CVI.00413-05DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489559PMC
June 2006

Clinical evaluation of macrolide-resistant Mycoplasma pneumoniae.

Antimicrob Agents Chemother 2006 Feb;50(2):709-12

Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Tokyo, Japan.

Macrolide-resistant Mycoplasma pneumoniae (MR M. pneumoniae) has been isolated from clinical specimens in Japan since 2000. A comparative study was carried out to determine whether or not macrolides are effective in treating patients infected with MR M. pneumoniae. The clinical courses of 11 patients with MR M. pneumoniae infection (MR patients) treated with macrolides were compared with those of 26 patients with macrolide-susceptible M. pneumoniae infection (MS patients). The total febrile days and the number of febrile days during macrolide administration were longer in the MR patients than in the MS patients (median of 8 days versus median of 5 days [P = 0.019] and 3 days versus 1 day [P = 0.002], respectively). In addition, the MR patients were more likely than the MS patients to have had a change of the initially prescribed macrolide to another antimicrobial agent (63.6% versus 3.8%; odds ratio, 43.8; P < 0.001), which might reflect the pediatrician's judgment that the initially prescribed macrolide was not sufficiently effective in these patients. Despite the fact that the febrile period was prolonged in MR patients given macrolides, the fever resolved even when the initial prescription was not changed. These results show that macrolides are certainly less effective in MR patients.
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http://dx.doi.org/10.1128/AAC.50.2.709-712.2006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1366908PMC
February 2006

[Evaluation of ELISA kits for detection of Mycoplasma pneumoniae--specific IgG, IgA, IgM antibodies on the diagnosis of Mycoplasma pneumoniae infection in children].

Authors:
Mitsuo Narita

Kansenshogaku Zasshi 2005 Jul;79(7):457-63

Department of Pediatrics, Sapporo Tetsudo Hospital.

A retrospective study was conducted to evaluate the utility of Mycoplasma pneumoniae IgG (quantitative), IgA (quantitative), IgM (qualitative) ELISA kits (Medac Diagnostika, Germany) for the diagnosis of M. pneumoniae pneumonia in children under 16 years of age. This study included a total of 159 serum samples from 113 patients with acute respiratory diseases such as bronchitis, pneumonia, which were classified into three groups according to the results of a particle agglutination (PA) test as a reference method, that is, Group I (Mycoplasma-definite cases): Group I-a (paired 52 samples from 26 cases); a four-fold or greater rise of antibody from an acute phase PA titer of < or = 1:80, Group I-b (paired 12 samples from 6 cases); a four-fold or greater rise of antibody from an acute phase PA titer of > or = 1:160, Group I-c (48 samples from 38 cases); a single high PA titer of > or = 1:640 either or both in acute or convalescent serum, Group II (Mycoplasma-probable cases, 18 samples from 17 cases): a PA titer of 1:160 or 320 was observed either or both in acute or convalescent serum, but the above serological criteria for Group I were not fulfilled, Group III (non-cases, 29 samples from 26 cases): a PA titer of any sample was < or = 1:80. The ELISA tests were performed according to the supplier's recommendations, and the results were classified according to the interpretation provided by the supplier: Early stage of infection (category 1,2), Acute- (3,4,5), Current- (6), Past- (7), and No-infection (8). The day of onset of fever (defined as a body temperature of > or = 37.5 degrees Celsius) was denoted as day 0. As a result from Group I, the category initially observed following the onset of fever was category 8 (triple negative), and the predominance of category 8 was replaced by category 1 (IgM solely positive) after day 4, followed by a shift of predominance to category 4 (IgM and IgG double positive) or 5 (triple positive) after day 10 or later. Specifically, category 1 was rather exclusively observed before day 21 following the onset of fever. These results suggest that category 1, when observed, is a useful marker of acute infection by Mycoplasma pneumoniae in children because it appears early in the acute phase and no longer observed beyond the convalescent phase. On the other hand, significance of detecting IgA antibody, which must be important for adults, was not remarkable in our study. Five samples in group II and 3 samples in group III fell into category 1. Whether or not such cases, in the absence of significant PA titers, can be taken actually as mycoplasmal infection remains to be clear. This study validated the utility of this ELISA methodology in terms of the acute phase diagnosis using a single point serum sample for Mycoplasma pneumoniae infection specifically in children.
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http://dx.doi.org/10.11150/kansenshogakuzasshi1970.79.457DOI Listing
July 2005

Cytokines involved in CNS manifestations caused by Mycoplasma pneumoniae.

Pediatr Neurol 2005 Aug;33(2):105-9

Department of Pediatrics, Sapporo Tetsudo (JR) Hospital, Sapporo, Japan.

Mycoplasma pneumoniae sometimes causes central nervous system manifestations, which may involve the host immune response, as the organism does not directly damage neural cells, or release toxins. Therefore we measured the levels of interleukin-6, interleukin-8, interleukin-18, interferon-gamma, tumor necrosis factor-alpha, and transforming growth factor-beta1 in serum and cerebrospinal fluid samples from patients who manifested central nervous system manifestations during acute M. pneumoniae infection. The subjects were nine patients with early-onset encephalitis (central nervous system disease onset within 7 days from the onset of fever), four with late-onset encephalitis (onset at 8 days or later), three with encephalitis but without fever, and three with aseptic meningitis. Intrathecal elevations of interleukin-6 and interleukin-8 in all four types of central nervous system manifestations, and of interleukin-18 in late-onset encephalitis were observed. None of the cerebrospinal fluid samples contained detectable levels of interferon-gamma, tumor necrosis factor-alpha, or transforming growth factor-beta1. In conclusion, interleukin-6, interleukin-8, and interleukin-18 might be involved in the inflammatory process leading to the central nervous system manifestations caused by M. pneumoniae.
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http://dx.doi.org/10.1016/j.pediatrneurol.2005.03.003DOI Listing
August 2005

Characterization and molecular analysis of macrolide-resistant Mycoplasma pneumoniae clinical isolates obtained in Japan.

Antimicrob Agents Chemother 2004 Dec;48(12):4624-30

Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Tokyo, Japan.

In recent years, Mycoplasma pneumoniae strains that are clinically resistant to macrolide antibiotics have occasionally been encountered in Japan. Of 76 strains of M. pneumoniae isolated in three different areas in Japan during 2000 to 2003, 13 strains were erythromycin (ERY) resistant. Of these 13 strains, 12 were highly ERY resistant (MIC, > or =256 microg/ml) and 1 was weakly resistant (MIC, 8 microg/ml). Nucleotide sequencing of domains II and V of 23S rRNA and ribosomal proteins L4 and L22, which are associated with ERY resistance, showed that 10 strains had an A-to-G transition at position 2063 (corresponding to 2058 in Escherichia coli numbering), 1 strain showed A-to-C transversion at position 2063, 1 strain showed an A-to-G transition at position 2064, and the weakly ERY-resistant strain showed C-to-G transversion at position 2617 (corresponding to 2611 in E. coli numbering) of domain V. Domain II and ribosomal proteins L4 and L22 were not involved in the ERY resistance of these clinical M. pneumoniae strains. In addition, by using our established restriction fragment length polymorphism technique to detect point mutations of PCR products for domain V of the 23S rRNA gene of M. pneumoniae, we found that 23 (24%) of 94 PCR-positive oral samples taken from children with respiratory infections showed A2063G mutation. These results suggest that ERY-resistant M. pneumoniae infection is not unusual in Japan.
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http://dx.doi.org/10.1128/AAC.48.12.4624-4630.2004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC529214PMC
December 2004
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