Daiki Ozawa

An analysis of clinical risk factors of deep neck infection.

OBJECTIVES To clarify the clinical risk factors that aggravate deep neck infection. PATIENTS AND METHODS Sixty-five patients with deep neck infection (abscess or cellulitis), 42 males and 23 females, who were treated at the ear, nose, and throat department in Iwaki Kyoritsu General Hospital in the past 10 years, were retrospectively reviewed. Cases of inflammation of the upper airway including the oral cavity, laryngopharynx, palate tonsil and salivary gland, and cases of lymphadenitis were investigated. These patients were divided into five localized types and one wide range type according to the abscess locations as follows: oral cavity floor type, upper deep cervical type, submandibular type, submental type, retropharyngeal type, and wide range type. RESULTS Seventeen of the 65 patients had diabetes, and significantly more diabetics had the wide range type than the localized type (P<0.05, Fishers test). Diabetes complication was more often seen in the upper deep cervical type among patients aged 61 years or older, and in the wide range type among males aged 41 years or older and elderly women aged 61 years or older. No patients with odontogenic infection or sialolithiasis had associated diabetes mellitus. Two cases developed mediastinitis, and one was caused by retrotonsillar abscess and needed thoracic drainage. More than half of the wide range type cases and more than a quarter of each of the localized type cases except the upper deep cervical type also had laryngeal edema, and eight of them needed emergency tracheotomy. Thirteen of the 40 cases had bacteria belonging to the Streptococcus milleri group (SMG), and all were detected in patients who underwent surgical drainage. Four of the 13 cases where SMG was detected showed drug resistance to some sorts of antibiotics. CONCLUSION Oral disorders can develop deep neck infection independently of the presence of diabetes mellitus, compared with other causes. The presence of diabetes mellitus is associated with deep neck infection, aggravating parotitis and wide spread of inflammation. Retrotonsillar abscess often spreads to the retropharyngeal and parapharyngeal spaces, causing mediastinitis, so caution is necessary. Infection due to SMG tends to form abscess independently of diabetes mellitus. Since more than half of the wide range type and more than a quarter of each of the localized types except the upper deep cervical type were associated with laryngeal edema, airway management should be considered.

Clinical and bacteriological influence of diabetes mellitus on deep neck infection: Systematic review and meta-analysis

Diabetes mellitus has been recognized as the most common systemic disease associated with deep neck infection. We report the first systematic review and meta‐analysis of the influence of diabetes on clinical and bacteriological characteristics of deep neck infection.

Impact of the Seven-valent Pneumococcal Conjugate Vaccine on Acute Otitis Media in Japanese Children: Emergence of Serotype 15A Multidrug-resistant Streptococcus pneumoniae in Middle Ear Fluid Isolates.

Background: Streptococcus pneumoniae is one of the most common bacteria causing acute otitis media (AOM). In Japan, a 7-valent pneumococcal conjugate vaccine (PCV7) was introduced for voluntary vaccination of children in 2010, and it became a recommended vaccination in April 2013. We surveyed the serotypes and antimicrobial susceptibility profile of S. pneumoniae isolates obtained from the middle ear fluid of Japanese children with AOM. Methods: Between April and September 2013, a total of 176 S. pneumoniae isolates were obtained from the middle ear fluid of children aged 0–3 years with AOM. Isolates were collected from various regions of Japan. Minimum inhibitory concentrations were measured by the broth microdilution method. Serotyping was performed by observing the Quellung reaction. Results: Although 45.5% of the strains were susceptible to penicillin G, 42.6% were penicillin-intermediate strains and 11.9% were penicillin-resistant strains. Serotype 19A (27.3%), serotype 15A (14.2%) and serotype 3 (11.9%) showed a high frequency. Although PCV7 types only accounted for 4.5% of all strains, 44.9% were PCV13 types and 55.1% were non-PCV types. Serotype 15A strains were 100% nonsusceptible to penicillin G and all of these strains showed multidrug resistance. Serotype 15A was frequent in children up to 1 year old. Conclusion: After this research was completed, PCV7 was switched to a PCV13 that also contained serotype 3 and serotype 19A. We need to consider the possibility that serotype 15A, which is not included in PCV13, may increase and cause intractable AOM in the future.

Microbiological and molecular epidemiological analyses of community-associated methicillin-resistant Staphylococcus aureus at a tertiary care hospital in Japan.

Molecular characterization of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is generally conducted referred to staphylococcal cassette chromosome mec (SCCmec) type IV or V. CA-MRSA is now a cause of concern since such strains have been isolated not only from individuals in a community but also from patients in healthcare settings. The aim of this study was to analyze microbiological and molecular epidemiological features of CA-MRSA strains at a Japanese tertiary care hospital using PCR based-open reading frame typing (POT). This technique allows for molecular classification into CA-MRSA (POT-CA) and hospital-associated (HA-) MRSA (POT-HA) with clonal discrimination. Clinical MRSA isolates obtained from consecutive patients between October 1, 2012 and September 30, 2013 at the hospital were analyzed in combination with the clinical definition for CA-MRSA by the Centers for Disease Control and Prevention and POT. Of 219 isolates (76 clonal groups), 64 (29.3%) were clinical-HA/POT-CA isolates (22 clonal groups). Some clones of them accumulated in this hospital and might be involved in nosocomial transmission. Virulent factors of the isolates were analyzed, and only one (1.6%) Panton-Valentine leukocidin gene positive isolate but no arginine catabolic mobile element genes positive isolate were found in clinical-HA/POT-CA. Additionally, clinical-HA/POT-CA isolates showed higher antimicrobial susceptibility than clinical-HA/POT-HA, especially to minocycline, doxycycline, and amikacin. The most frequent genotype of molecular CA-MRSA was multi-locus sequence type 5-SCCmecIV, previously not detected in Japan. Although CA-MRSA at this hospital showed low virulence and higher antimicrobial susceptibility, the risk of nosocomial infection from them should be recognized, requiring stricter infection control measures.

Molecular Epidemiology of Ampicillin-resistant Haemophilus influenzae Causing Acute Otitis Media in Japanese Infants and Young Children.

Background: Nontypeable Haemophilus influenzae is a particularly important cause of acute otitis media (AOM). There is a high prevalence of &bgr;-lactamase–nonproducing ampicillin-resistant (BLNAR) strains in Japanese children, which is associated with recurrent AOM and prolonged treatment. The aim of this study was to investigate the antimicrobial susceptibility profile, mechanisms of ampicillin resistance and molecular epidemiology of ampicillin resistance in H. influenzae strains causing AOM in Japanese children. Methods: One hundred fifty-seven strains of H. influenzae isolated from the middle ear fluid of pediatric patients (aged 0–3 years) with AOM from various areas of Japan were studied. The antimicrobial susceptibility profile, genes encoding &bgr;-lactamase and alterations of penicillin-binding protein 3 were investigated. Genetic relatedness among ampicillin-resistant isolates was examined by multilocus sequence typing and pulsed-field gel electrophoresis. Results: Of 157 isolates, 108 (68.8%) demonstrated reduced susceptibility to ampicillin, including 95 (60.5%) of &bgr;-lactamase–nonproducing isolates and 13 (8.3%) of &bgr;-lactamase–producing isolates. All BLNAR (minimum inhibitory concentration of ampicillin ≥ 4 mg/L) isolates had amino acid substitutions related to ampicillin resistance. Multilocus sequence typing and pulsed-field gel electrophoresis demonstrated genetic diversity although there were 2 clusters of highly resistant isolates with identical STs (sequence types; ST161 and 549). Conclusions: Alterations of penicillin-binding protein 3 represented the most prevalent mechanism of ampicillin resistance among H. influenzae isolates causing AOM in Japanese children. BLNAR isolates from children with AOM demonstrated genetic diversity. This study identified for the first time ST clones associated with BLNAR H. influenzae causing AOM in Japanese children.

Twelve-year survey (2001–2012) of the antimicrobial susceptibility of Streptococcus pneumoniae isolates from otorhinolaryngology clinics in Miyagi Prefecture, Japan

INTRODUCTION Streptococcus pneumoniae is one of the most common bacteria causing otorhinolaryngological infections, such as acute otitis media and upper respiratory tract infection. Our group surveyed the drug susceptibility profile of S. pneumoniae isolates from otorhinolaryngology patients. MATERIALS AND METHODS A total of 41,069 S. pneumoniae isolates were detected at Miyagi Medical Association Health Center between May 2001 and December 2012. Specimens were obtained from patients at 40 otorhinolaryngology outpatient clinics in Miyagi Prefecture, Japan. The minimum inhibitory concentrations (MICs) of 8 antimicrobial agents were measured using the broth microdilution method according to Clinical and Laboratory Standards Institute guidelines. RESULTS In children aged 0-2 years old, the MIC50 values of penicillins decreased after 2010 (PCG: 1 μg/ml (2010) to 0.06 μg/ml (2012); ABPC: 1 μg/ml (2010) to 0.25 μg/ml (2012)). The prevalence of penicillin-resistant S. pneumoniae (PRSP) decreased from 35.2% (2010) to 14.6% (2012) in rhinorrhea specimens and from 43.4% (2010) to 14.3% (2012) in otorrhea specimens. Susceptibility to cephems (ceftriaxone and cefditoren) and carbapenems (panipenem) also showed improvement after 2010. For macrolides (clarithromycin) and lincosamides (clindamycin), MIC50 values increased in all age groups during the study period, and a high level of resistance was seen until 2012. There were no marked changes of susceptibility to fluoroquinolones (LVFX) during the study period. CONCLUSION Improvement of susceptibility of S. pneumoniae to β-lactams occurred after 2010 in Miyagi Prefecture, Japan.

Outcomes of frontal mucoceles treated with conventional endoscopic sinus surgery.

Abstract Conclusion: Conventional endoscopic sinus surgery (CESS) is useful for frontal mucoceles. A patient with short anterior–posterior distance and bone thickening may need an axillary flap, Draf type IIb, or Draf type III procedure. Objective: To present outcomes of frontal mucoceles treated with CESS and predict risk factors for poor outcomes to help define surgical indications. Methods: A consecutive clinical series was reviewed retrospectively. The authors performed CESS without agger nasi resection (Draf type IIa) for 13 frontal sinus mucoceles in 12 patients between October 2011 and July 2013. Patient age, sex, blood eosinophil count, history of operation and co-existence of acute infection were compared. For the condition of the frontal sinus, anterior–posterior distance and width of frontal recess, bone thickening of the frontal recess, bone absorption due to continuous pressure by mucocele and anatomy of the frontal recess was noted. Results: All operations were done without a navigation system. The post-operative course was uneventful in all 12 patients, and all symptoms gradually receded. Among 13 mucoceles, one frontal sinus (7.7%) closed during follow-up.

Detection of Chlamydia trachomatis or Neisseria gonorrhoeae in otorhinolaryngology patients with pharyngeal symptoms

As sexual behaviour has become more diversified, oral sex has become common (especially among younger people) and urogenital micro-organisms, such as Chlamydia trachomatis or Neisseria gonorrhoeae , are also being detected in the pharynx.1– ,5 We performed testing for pharyngeal C trachomatis and N gonorrhoeae in patients with pharyngeal symptoms. Among patients who presented at Tohoku Rosai Hospital otorhinolaryngology outpatient clinic with acute tonsillitis, acute pharyngitis or abnormal pharyngeal sensation syndrome between June 2012 and March 2013, 225 patients gave written informed consent to the collection of specimens and were enrolled …

Prevalence of Smqnr and plasmid-mediated quinolone resistance determinants in clinical isolates of Stenotrophomonas maltophilia from Japan: novel variants of Smqnr

Stenotrophomonas maltophilia is an important pathogen in healthcare-associated infections. S. maltophilia may contain Smqnr, a quinolone resistance gene encoding the pentapeptide repeat protein, which confers low-level quinolone resistance upon expression in a heterologous host. We investigated the prevalence of Smqnr and plasmid-mediated quinolone resistance (PMQR) determinants in S. maltophilia isolates from Japan. A total of 181 consecutive and nonduplicate clinical isolates of S. maltophilia were collected from four areas of Japan. The antimicrobial susceptibility profiles for these strains were determined. PCR was conducted for Smqnr and PMQR genes, including qnrA, qnrB, qnrC, qnrS,aac(6′)-Ib and qepA. PCR products for Smqnr and aac(6′)-Ib were sequenced. For the S. maltophilia isolates containing Smqnr, pulsed-field gel electrophoresis (PFGE) was performed using XbaI. Resistance rates to ceftazidime, levofloxacin, trimethoprim–sulfamethoxazole, chloramphenicol and minocycline were 67.4%, 6.1%, 17.7%, 8.8% and 0%, respectively. The minimum inhibitory concentration required to inhibit the growth of 50% and 90% of organisms were 0.5 and 2 mg/L for moxifloxacin but 1 and 4 mg/L for levofloxacin, respectively. Smqnr was detected in 104 of the 181 S. maltophilia isolates (57.5%), and the most frequent was Smqnr6, followed by Smqnr8 and Smqnr11. Eleven novel variants from Smqnr48 to Smqnr58 were detected. The 24 Smqnr-containing S. maltophilia isolates were typed by PFGE and divided into 21 unique types. Nine S. maltophilia isolates (5.0%) carried aac(6′)-Ib-cr. No qnr or qepA genes were detected. This study describes a high prevalence of Smqnr and novel variants of Smqnr among S. maltophilia from Japan. Continuous antimicrobial surveillance and further molecular epidemiological studies on quinolone resistance in S. maltophilia are needed.

Minimally Invasive Treatment for Hard Palate-Invading Maxillary Keratocystic Odontogenic Tumor

Keratocystic odontogenic tumor (KCOT) is one of the benign developmental odontogenic cystic lesions arising from impacted teeth. In comparison to other odontogenic cysts, such as radicular cysts and dentigerous cysts, KCOT is known to be more aggressive and is associated with a relatively high recurrence rate. Traditionally, KCOT has been treated with total resection through sublabial incision. Marsupialization is advocated to reduce surgical invasion. However in all the cases, marsupialization was performed in the oral cavity. With the recent development of appropriate instruments and the endoscopic modified medial maxillectomy (EMMM) technique, which allows preservation of the inferior turbinate and nasolacrimal duct, an exclusive endoscopic approach to KCOT becomes possible. However, when the KCOT invades the hard palate, total resection of the tumor requires subtotal maxillectomy including hard palate. Consequently, as the maxillary sinus connects to the oral cavity, life-long use of a prosthesis becomes mandatory. Here we report a case of a seventeen-year-old female with a hard palate-invading KCOT who was successfully treated with the EMMM approach. The KCOT was fenestrated to the nasal cavity, leading to preservation of the hard palate. The lesion invading the hard palate was found to remain unchanged over one year upon follow-up. The trans-nasal approach with EMMM is a direct, minimally invasive method providing a direct field of view for the treatment of maxillary odontogenic cysts. Marsupialization of the KCOT with the EMMM technique might be a viable treatment option if the maxillary KCOT invades surrounding structures.