Traditional Japanese herbal medicine Hochuekkito protects development of sepsis after nasal colonization in mice.

INTRODUCTION: Streptococcus pneumoniae, a commensal in the nasopharynx, can cause invasive pneumococcal diseases (IPDs). To prevent the aggravation of IPDs, it is important to enhance host immune defense against S. pneumoniae. Hochuekkito (HET) is expected to have an immunostimulatory effect against infections. METHODS: HET was administrated by gavage to adult BALB/cA mice before and after intranasal inoculation of S. pneumoniae. We evaluated the effect of HET on pneumococcal nasal colonization and subsequent development of lethal pneumococcal infections. RESULTS: No effect on nasal colonization was observed, but HET significantly reduced bacterial count in the blood, decreased the incidence of bacteremia, and improved survival. HET also reduced nasal tissue damage 3 days after intranasal infection. Neutrophils from HET-treated mice showed significantly higher bactericidal activity against S. pneumoniae in the presence of the serum from the HET group compared with from the control group. CONCLUSIONS: The non-specific immunostimulatory effect of HET is suggested by this study to be effective in preventing the progression in IPDs and provided insights into novel strategy in the post-pneumococcal vaccine era.

Factors affecting the antimicrobial changes during treatment for acute otitis media in Japan: A retrospective cohort study using classification and regression trees (CART) analysis.

OBJECTIVES: Factors that affect the change of first-line antimicrobial agents were investigated to further promote their appropriate use. METHODS: This descriptive study used an electronic medical records database. Total 16,353 of the 199,896 patients enrolled between 1996 and 2019 met the inclusion criteria and formed the overall pediatric acute otitis media (AOM) cohort. The factors leading to the change in first-line antimicrobial agents within 14 days were analyzed using classification and regression trees (CART) analysis. RESULTS: This antimicrobial treatment cohort, involved 4860 cases of AOM alone and 9567 cases of AOM with other diseases. The size of the medical facility based on number of beds and historical duration of patient registration impacted on antimicrobial changes. CONCLUSIONS: The current results show that hospital-wide or nation-wide antimicrobial stewardship promotion could be the most influencing factor for antimicrobial changes. Particularly in cases of AOM where other diseases coexist, a more accurate diagnosis and definition of treatment failure of first-line drug are suggested to be important while establishing future treatment strategies. The current study is important to promote appropriate antimicrobial use for AOM treatment.

A rapid simultaneous antigen detection of Haemophilus influenzae and Streptococcus pneumoniae for predicting the prognosis of acute otitis media.

BACKGROUND: Rapid identification of causative bacteria in treatment of acute otitis media (AOM) is of paramount importance for appropriate antibiotic use. MATERIALS AND METHODS: This prospective observational study was conducted in 15 hospitals and clinics in Japan between 2018 and 2020. A new rapid antigen test kit (AOS-116), which simultaneously detects antigens for Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi), was applied for middle ear fluids (MEFs) and nasopharyngeal secretions (NPSs) in patients with moderate to severe AOM. We investigated relationship between the results of rapid test, severity at initial visit, and clinical course. RESULTS: Regarding performance accuracy based on culture results, AOS-116 showed 1) high (>80%) sensitivity, specificity, and negative predictive value (NPV) in MEFs for both antigens, 2) high sensitivity, specificity, and positive predictive value (PPV) in NPSs for Hi antigen, and 3) high specificity, and PPV in NPSs for Sp antigen. Regarding predictive value of nasopharyngeal culture and antigen detection for causative middle ear pathogens, similar results were observed between AOS-116 and culture, which was characterized with high sensitivity and NPV for both pathogens. MEFs/NPSs positive for Hi antigen were significantly associated with eardrum findings, and severity. MEFs/NPSs positive for pneumococcal antigen were significantly associated with severity of otalgia, fever, and otorrhea. Among patients with prior antimicrobial treatment, improvement tended to be slower in cases positive for Hi than in cases negative. CONCLUSION: The rapid antigen detection test is useful as a decision-making tool for prescribing antimicrobial agents and may play an important role in promoting appropriate antimicrobial use.

The Roles of Transient Receptor Potential Vanilloid 1 and 4 in Olfactory Regeneration.

Olfactory disorders, which are closely related to cognitive deterioration, can be caused by several factors, including infections, such as COVID-19; aging; and environmental chemicals. Injured olfactory receptor neurons (ORNs) regenerate after birth, but it is unclear which receptors and sensors are involved in ORN regeneration. Recently, there has been great focus on the involvement of transient receptor potential vanilloid (TRPV) channels, which are nociceptors expressed on sensory nerves during the healing of damaged tissues. The localization of TRPV in the olfactory nervous system has been reported in the past, but its function there are unclear. Here, we investigated how TRPV1 and TRPV4 channels are involved in ORN regeneration. TRPV1 knockout (KO), TRPV4 KO, and wild-type (WT) mice were used to model methimazole-induced olfactory dysfunction. The regeneration of ORNs was evaluated using olfactory behavior, histologic examination, and measurement of growth factors. Both TRPV1 and TRPV4 were found to be expressed in the olfactory epithelium (OE). TRPV1, in particular, existed near ORN axons. TRPV4 was marginally expressed in the basal layer of the OE. The proliferation of ORN progenitor cells was reduced in TRPV1 KO mice, which delayed ORN regeneration and the improvement of olfactory behavior. Postinjury OE thickness improved faster in TRPV4 KO mice than WT mice but without acceleration of ORN maturation. The nerve growth factor and transforming growth factor ß levels in TRPV1 KO mice were similar to those in WT mice, and the transforming growth factor ß level was higher than TRPV4 KO mice. TRPV1 was involved in stimulating the proliferation of progenitor cells. TRPV4 modulated their proliferation and maturation. ORN regeneration was regulated by the interaction between TRPV1 and TRPV4. However, in this study, TRPV4 involvement was limited compared with TRPV1. To our knowledge, this is the first study to demonstrate the involvement of TRPV1 and TRPV4 in OE regeneration.

Bactericidal effect of lascufloxacin on HEp-2 cell-internalized group A Streptococcus.

INTRODUCTION: Although amoxicillin (AMPC) is recommended as first-line therapy for acute pharyngotonsillitis caused by group A streptococci (GAS), it often fails to eradicate infections. Internalization and subsequent intracellular survival of GAS are considered major mechanisms for penicillin therapeutic failure. It is, therefore, desirable to administer drugs that exert bactericidal effects on extracellular and intracellular GAS. In this study, we aim to investigate the bactericidal effects of lascufloxacin (LSFX) on internalized GAS in HEp-2 cells. MATERIALS AND METHODS: The GAS strain M1 and clinical isolate strain #2 were used in this study. Following treatment of GAS-infected human pharyngeal carcinoma epithelial HEp-2 cells with LSFX or AMPC, internalized GAS cells were recovered. The concentrations of LSFX and AMPC were equivalent to 1 × and 2 × MIC for strain M1. Culture medium was used as a control. Time-lapse and fluorescence images of GAS invading HEp-2 cell were obtained. LIVE/DEAD fluorescence staining was used to confirm the viability of internalized GAS. RESULTS: LSFX significantly reduced the number of cell-internalized M1 and #2 GAS strains compared to the control (p < 0.01) in a dose-dependent manner. However, AMPC did not reduce this in both strains. Both live and dead intracellular GAS were confirmed in HEp-2 cells exposed to LSFX. In contrast, intracellular GAS survived in HEp-2 cells exposed to AMPC and in the control. CONCLUSION: LSFX elicits significant bactericidal effects on cell-internalized GAS, hence it may represent a potent therapeutic option for patients with acute pharyngotonsillitis in whom AMPC treatment has failed.

Improvement of Surgical View and Working Space at the Lower Pole by Three-Dimensional Exoscope-Assisted Coblation Tonsillectomy: A Case Series.

Advantages of hot devices for tonsillectomy, represented by coblation, have been highlighted in recent years. During hot technique tonsillectomy it is important to identify and coagulate the vessels of the tonsillar capsule, especially at the lower pole of the tonsil. Hot technique tonsillectomy under microscope or endoscope has therefore been recommended to achieve accurate identification of the microstructure of the surgical field. We have applied ORBEYE, a three-dimensional surgical exoscope system, to coblation tonsillectomy. Advantages of using ORBEYE include high definition and high magnification images, and flexibility of camera position and angle. This means there is an improved surgical view and working space, particularly at the lower pole during performance of coblation tonsillectomy. Here, we demonstrate that ORBEYE can be an effective surgical instrument in coblation tonsillectomy.

Chondroma Arising from the Temporomandibular Joint: A Case Report.

Periarticular chondromas are common in the humerus and femur but rarely occur in the temporomandibular joint. We report a case of a chondroma in the anterior part of the ear. One year prior to his visit, a 53-year-old man became aware of swelling in the right cheek region which gradually increased in size. In the anterior part of the right ear, there was a palpable 25 mm tumor, elastic and hard, with poor mobility and without tenderness. A contrast-enhanced computed tomography CT showed a mass lesion with diffuse calcification or ossification in the upper pole of the parotid gland and areas of poor contrast within. A magnetic resonance imaging showed a low-signal mass lesion at the parotid gland with some high signals in both T1 and T2. Fine-needle aspiration cytology did not lead to diagnosis. Using a nerve monitoring system, the tumor was resected with normal tissue of the upper pole of the parotid gland in the same way as for a benign parotid tumor. Distinguishing between pleomorphic adenoma, including diffuse microcalcification of the parotid gland and cartilaginous tumors of the temporomandibular joint, may be sometimes difficult. In such cases, surgical resection may be a beneficial treatment option.

A Novel Pneumococcal Surface Protein K of Nonencapsulated Streptococcus pneumoniae Promotes Transmission among Littermates in an Infant Mouse Model with Influenza A Virus Coinfection.

We established an infant mouse model for colonization and transmission by nonencapsulated Streptococcus pneumoniae (NESp) strains to gain important information about its virulence among children. Invasive pneumococcal diseases have decreased dramatically since the worldwide introduction of pneumococcal capsular polysaccharide vaccines. Increasing prevalence of nonvaccine serotypes, including NESp, has been highlighted as a challenge in treatment strategy, but the virulence of NESp is not well understood. Protective strategies against NESp colonization and transmission between children require particularly urgent evaluation. NESp lacks capsules, a major virulence factor of pneumococci, but can cause a variety of infections in children and older people. PspK, a specific surface protein of NESp, is a key factor in establishing nasal colonization. In our infant mouse model for colonization and transmission by NESp strains, NESp could establish stable nasal colonization at the same level as encapsulated serotype 6A in infant mice and could be transmitted between littermates. Transmission was promoted by NESp surface virulence factor PspK and influenza virus coinfection. However, PspK deletion mutants lost the ability to colonize and transmit to new hosts. Promotion of NESp transmission by influenza was due to increased susceptibility of the new hosts. PspK was a key factor not only in establishment of nasal colonization but also in transmission to new hosts. PspK may be targeted as a new candidate vaccine for NESp infection in children.

Impact of the practical guideline on appropriate usage of antimicrobial treatments for surgical site infections in reconstructive surgery of head and neck cancer.

OBJECTIVES: In 2016, Japanese Society of Chemotherapy and Japan Society for Surgical Infection presented the practical guideline for appropriate usage of antimicrobial agents to prevent postoperative infections. This study aims to exhibit the validity of the guideline as a series of effective strategies for prevention of surgical site infections (SSIs) during reconstructive surgery of the head and neck cancer. METHODS: We retrospectively evaluated patients who underwent head and neck reconstructive surgery with free or pedicle flaps in a single institute in Japan between July 2010 and July 2020. We evaluated the incidence of SSIs, patient backgrounds, and microbiological characteristics on the basis of antimicrobial prophylaxis recommended by the guideline. RESULTS: Enrolled in this study were 102 patients in our institution who underwent head and neck reconstructive surgery with free or pedicle flaps between July 2010 and July 2020. In the period between January 2018 to July 2020 after the SSI guideline was advocated (SSI guideline period), the ratio of administration of sulbactam/ampicillin (SBT/ABPC) was significantly higher (P < 0.001) and the duration of prophylactic antimicrobial treatment was significantly shorter than in the period between July 2010 to December 2017 before the SSI guideline was advocated (Pre-SSI guideline period) (P < 0.001). Incidence of SSIs were similar, even when antibiotic use was changed to be short-term single-agent administration in accordance with the practical guideline. CONCLUSIONS: Adherence to the current Japanese practical guideline on appropriate antimicrobial prophylaxis for SSIs can shorten the duration of usage of antimicrobial treatment without increasing the risk for occurrence of SSIs.

Respiratory quinolones can eradicate amoxicillin-induced mature biofilms and nontypeable Haemophilus influenzae in biofilms.

OBJECTIVES: Biofilm is thought to be involved in the persistent bacterial infections caused by nontypeable Haemophilus influenzae (NTHi). This study aims to evaluate the efficacy of antibiotics against NTHi biofilms. METHODS: A 96-wells pin replicator assay was applied for evaluation of antimicrobial efficacies against NTHi biofilms. The NTHi IH-202 strain for the standard and 10 clinical strains were evaluated, as well as the viability of NTHi in biofilms after antimicrobial exposures. RESULTS: Biofilms formed by IH-202 strain accumulated during incubation. AMPC if not high concentrations, neither reduce or inhibit biofilm formation, nor eradicate matured NTHi biofilms. The NTHi in matured biofilm were alive after exposure to amoxicillin (AMPC). Even high concentration of AMPC produced live NTHi after suspension of exposure, while tosufloxacin and garenoxacin inhibited biofilm formation of NTHi and eradicated matured biofilms. The respiratory quinolones, but not AMPC, killed NTHi in biofilms even at sub-MIC. CONCLUSIONS: NTHi persists in biofilms, even after exposure to AMPC. These findings may eventually lead to a better understanding of effective use of antibiotics to eradicate NTHi growing as biofilms, or even to the development of novel therapeutic agents for treating patients with mucosal NTHi biofilm infections. Meanwhile, respiratory quinolones are attractive agents in reducing NTHi biofilm formation and destroying established biofilm.

Investigation on the virulence of non-encapsulated Streptococcus pneumoniae using liquid agar pneumonia model.

INTRODUCTION: Since the introduction of pneumococcal conjugate vaccine, there have been warnings of an increase in infections caused by non-vaccine type of Streptococcus pneumoniae strains. Among them, nonencapsulated Streptococcus pneumoniae (NESp) has been reported to cause invasive infections, especially in children and the elderly. Due to low virulence, however, basic experimental reports on invasive infections are limited. METHODS: We applied a liquid-agar method to establish a mouse model of invasive NESp infection. Mice were intratracheally administered a bacterial suspension including agar. With this technique, we investigated the pathogenicity of NESp and the effect of Pneumococcal surface protein K (PspK), a specific surface protein antigen of NESp. NESp wild-type strain (MNZ11) and NESp pspK-deleted mutant strain (MNZ1131) were used in this study. The survival rate, number of bacteria, cytokine/chemokine levels in the bronchoalveolar lavage fluid, and histology of the lung tissue were evaluated. RESULTS: Mice that were intratracheally administered MNZ11 developed lethal pneumonia with bacteremia within 48 h. Conversely, MNZ1131 showed predominantly low lethality without significant pro-inflammatory cytokine production. NESp was found to cause severe pneumonia and bacteremia upon reaching the lower respiratory tract, and PspK was a critical factor of NESp for developing invasive infections. CONCLUSIONS: The current study demonstrated the ability of NESp to develop invasive diseases, especially in connection with PspK by use of a mouse pneumonia model.

Pneumococcal capsular phase shift is associated with invasion into cell-to-cell junctions and is inhibited by macrolides.

Streptococcus pneumoniae frequently colonizes the human nasopharynx beginning in the early childhood. Pneumococci exhibit a spontaneous and reversible phase shift between opaque and transparent allowing them to adapt to different environments. This is the first report of the dynamics of pneumococcal phase shift during the course of adhesion and subsequent invasion into epithelial cell monolayers by bacteria-cell co-culture assay with a time-lapse microscopy. The invasion of an inoculum between the human epithelial cells was dependent on the transparent phenotype, but successful replication of the cells within the cell layer was strongly associated with its transformation into an opaque-like variant. We also observed that sub-MIC levels of clarithromycin inhibited the spontaneous pneumococcal phase shift. Our results show that the pneumococcus can modulate its fitness in part because it can switch phenotype in response to the environment during not only inflammation but also during the establishment of colonization. Our current findings provide a more in depth understanding not only of how the pneumococcal phase shift acts to protect pneumococci from commensal flora and the immune status of the host, but also illustrate a novel strategy for antimicrobial treatments to interfere with pneumococcal colonization.

Improvement in the appropriate antimicrobial usage for treating pediatric acute otitis media in Japan: A descriptive study using nation-wide electronic medical record data.

OBJECTIVES: We investigated changes in prescriptions for antimicrobial agents to treat children with acute otitis media (AOM). METHODS: A descriptive study using an electronic medical record database. Of 199,896 patients enrolled between 2001 and 2019, a total of 10,797 were aged <16 years and had AOM as their first and primary disease (overall pediatric AOM cohort). In addition, 4786 patients with AOM without other comorbidities (pediatric AOM cohort) were included. RESULTS: In the overall pediatric AOM cohort, the age distribution ranged from 11% to 23% for those younger than 2 years and from 66% to 77% for those younger than 6 years, with no change over time. In the pediatric AOM cohort, the antimicrobial prescription rate was 91% in 2001 but declined to 40% by 2019. Antimicrobial use increased from 0% to 75% for penicillins, whereas use of cephalosporins decreased from 84% to 10%. The prescription rate for acetaminophen alone increased from 33% to 58%. There were no differences in the incidence of adverse reactions among the prescribed antimicrobials. CONCLUSIONS: Due to education efforts and promotion of the proper use of antimicrobials through means such as the Clinical practice guidelines for the diagnosis and management of acute otitis media in children (2006) and the Manual of Antimicrobial Stewardship (2016), a change in the use of antimicrobials occurred, leading to a trend to more proper use of these agents.

Features predicting treatment failure in pediatric acute otitis media.

OBJECTIVES: To facilitate better antibiotic stewardship, we conducted this clinical trial to identify the prognostic features of treatment failure in pediatric acute otitis media (AOM). STUDY: Design: This is a randomized, parallel-group, open-label, comparative clinical trial. SUBJECTS AND METHODS: Children with AOM and aged between 1 month and 5 years were enrolled. Patients were randomly assigned to receive either amoxicillin alone (70 mg/kg) for five days, or the same with additional clarithromycin (15 mg/kg) for the initial three days. The clinical course of AOM was evaluated based on tympanic membrane scores. Failure of treatment for AOM was confirmed on day 14. Nasal conditions were also assessed by a clinical scoring system for acute rhinosinusitis. RESULTS: Treatment failures occurred in 25 out of 129 (19.4%) children. The ratio of treatment failures by age was significantly higher in children younger than 2 years than in children older than 2 years. The tympanic membrane scores on day 3 (P = 0.0334) and day 5 (P < 0.0001) and acute rhinosinusitis scores on day 5 (P = 0.0004) were higher in failure cases than in cured cases. Multivariate logistic regression analysis indicated significant associations between the treatment failure with tympanic membrane scores and acute rhinosinusitis scores on day 5, and the antimicrobial treatment regimen. CONCLUSIONS: Improvement of acute rhinosinusitis and tympanic membrane scores on day five were important predictive features in failure of treatment for pediatric AOM. These results will be useful when discussing the treatment decisions with the patient's parents.

Distinct clinical features and prognosis between persistent and temporary thyroid dysfunctions by immune-checkpoint inhibitors.

Immune-related adverse events in the thyroid glands (thyroid irAEs) during treatment with immune-checkpoint inhibitors (ICIs) are most frequent endocrine irAE. Thyroid irAE can be divided into that requiring continuous therapy for thyroid dysfunction (P-THY), and that requiring only temporal treatment (T-THY). However, predictive factors for those differential outcomes are unknown, and susceptibility of human leukocyte antigen (HLA) to thyroid irAE has never been investigated. This study aimed to elucidate clinical courses and prognosis of P-THY in comparison with T-THY in the aspect of thyroid immunity and HLA. Patients with P-THY (n = 15) that required L-T4 supplemental therapy for hypothyroidism for more than 3 months, and patients with T-THY who required no therapy or therapy within 1 month were enrolled in the study. Lower-value of TSH, higher-value of FT4, and lower value of TSH/FT4 were thought to be predictive markers to estimate P-THY. In addition, anti-thyroglobulin antibody (TgAb) levels were significantly higher in patients with P-THY than those in patients with T-THY. HLA-DPA1*01:03 and HLA-DPB1*02:01 allele, and their haplotype frequencies were significantly higher in patients with P-THY than those in controls. P-THY had better survival rate than T-THY. Pre-existing thyroid autoimmunity, the extent of thyroid dysfunction, and predisposing HLA were associated with the differential course of thyroid irAEs. It was suggested that thyroid function tests, TgAb, and HLA typing tests are useful for prediction of clinical course in thyroid irAEs.

A case report of synchronous bilateral tonsillar carcinoma associated with human papilloma virus.

The case of a 69-year-old man with bilateral synchronous tonsillar carcinoma is reported. The patient complained of nasal closure, strange voice, and discomfort in his pharynx when he was admitted to the Department of Otolaryngology Head and Neck Surgery at Wakayama Medical University, Wakayama, Japan, in March 2017. The palatine tonsils were enlarged and the surface was irregular. Left cervical lymphadenopathy was also evident. Histological examination from both tonsils was performed and bilateral tonsillar squamous cell carcinoma was diagnosed. PCR analysis showed the same HPV-DNA pattern from bilateral tonsils. Concurrent chemoradiotherapy was performed. Total 70 Gy of irradiation (2Gy/day×35 day) was applied to bilateral tonsillar tumours and upper neck. Follow up was conducted every three months and the patient was free of recurrence for three years. Patient's informed consent was taken to publish the case report.

The seventh nationwide surveillance of six otorhinolaryngological infectious diseases and the antimicrobial susceptibility patterns of the isolated pathogens in Japan.

The Japanese Three Academic Societies Joint Antimicrobial Susceptibility Surveillance Committee conducted a nationwide surveillance on six otorhinolaryngological diseases and investigated the antimicrobial susceptibility patterns and isolation rates of the causative pathogens. The surveillance program was conducted in the otorhinolaryngological departments of 12 universities, and 36 affiliated hospitals and clinics. Patients with acute otitis media (children under six years old), chronic otitis media, acute nasal sinusitis, chronic nasal sinusitis, acute tonsillitis, and peritonsillar abscess (over 20 years old) between December 2015 and June 2017 were investigated. The collected swab or incision samples were cultivated for microbial identification, and the antimicrobial susceptibility of the detected bacteria was measured at the Kitasato University Research Center for Infections and Antimicrobials. The surveillance focused on three gram-positive bacteria (Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus), three gram-negative bacteria (Haemophilus influenzae, Moraxella catarrhalis, and Pseudomonas aeruginosa), and three anaerobic bacteria (anaerobic gram-positive cocci, Prevotella spp., Porphyromonas spp., and Fusobacterium spp.). Bacterial susceptibility to 40 antimicrobial agents was investigated. We were unable to completely mitigate the rise in the occurrence of resistant bacteria, such as methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, penicillin-intermediate resistant S. pneumoniae, beta-lactamase non-producing ampicillin-resistant H. influenzae, and beta-lactamase producing ampicillin-resistant H. influenzae. We suggest promoting the proper usage of antimicrobial agents to prevent the spread of these bacteria. We also suggested that immunization with pneumococcal vaccines is useful for decreasing the occurrence of otorhinolaryngological infectious diseases caused by pneumococci.

False-positive staining of thyroglobulin distinguished from mixed medullary and follicular thyroid carcinoma by duplex in situ hybridization.

Medullary thyroid carcinoma (MTC) may mimic mixed medullary and follicular thyroid carcinoma (MMFTC). MTC originates from para-follicular cells, while MMFTC is an uncommon tumor characterized by coexistence of follicular and para-follicular cell-derived tumor populations. A 35-year-old woman was diagnosed with MTC but showed a hot nodule in thyroid scintigraphy. The tumor included diffusely-spread follicular lesions within it, which were immunostained with thyroglobulin and calcitonin. Immunofluorescence showed the presence of several tumor cells that were double-stained with thyroglobulin and calcitonin. To clarify whether or not the tumor was MMFTC, we used duplex in situ hybridization (ISH). Thyroglobulin and calcitonin-related polypeptide alpha mRNA were not expressed together in a single cell, so we suspected false-positive staining of tumor cells with thyroglobulin. To make comparisons with other follicular lesions in MTC, we searched our hospital database. Five cases within a ten-year period had been pathologically diagnosed as MTC. All had follicular lesions in the tumor, but unlike the other case, they were peripherally localized. Dual differentiation into follicular or para-follicular tumor cells was not indicated by either immunofluorescence or duplex ISH. Compared with the case suspected to be MMFTC, there was only mild invasion of tumor cells into the follicular epithelium. The extent of follicular lesions and invasiveness of tumor cells may be associated with pseudo-staining of thyroglobulin in MTC. Duplex ISH can distinguish MTC that are stained with thyroglobulin from MMFTC.

Molecular epidemiology of nonencapsulated Streptococcus pneumoniae among Japanese children with acute otitis media.

The introduction of pneumococcal conjugate vaccine may change the epidemiology of Streptococcus pneumoniae. The increased prevalence of non-vaccine serotypes as the cause of pneumococcal diseases has already reported in the United States and Europe. However, little attention has been focused on the S. pneumoniae. In this study, nonencapsulated S. pneumoniae were identified in 15 isolates (6.4%) out of 236 pneumococcal strains obtained from the nasopharynges of children with acute otitis media (AOM), in 3 isolates (14.3%) out of 21 strains from acute rhinosinusitis, and in 2 isolates (12.5%) out of 16 nasopharyngeal carriage strains obtained from normal healthy children. Among the 20 nonencapsulated S. pneumoniae isolates, 15 (75.0%) isolates had the pspK gene. Seven sequence types (STs) were identified: ST7502 (5 strains), ST1106 (2 strains), ST7803 (2 strains), ST7786 (1 strain), ST6741 (1 strain), ST7496 (1 strain), and ST8642 (1 strain). Because nonencapsulated S. pneumoniae strains are not targeted by the current available pneumococcal vaccines, these strains will gradually become more common in nasopharyngeal carriage. The increase in colonization and dissemination of these strains would increase the risk of AOM and other systemic pneumococcal diseases against which current vaccines cannot provide protection. Nonencapsulated S. pneumoniae may thus become more prevalent as human pathogen.