Streptococcus pneumoniae is a gram-positive coccus that causes invasive and non-invasive pneumococcal diseases. Invasive pneumococcal disease（IPD）is defined as an infection confirmed by the isolation of S. pneumoniae from a normally sterile site. IPD has a high mortality rate of around 20% in adults. Colonies of S. pneumoniae show various morphological features which include a mucoid appearance. The production of large amounts of capsular polysaccharide gives colonies of S. pneumoniae their mucoid appearance. This is thought to be a mechanism of microbial escape from phagocyte killing, leading to strong pathogenicity despite their high susceptibility to antibiotics. To our knowledge, the clinical characteristics of patients with mucoid IPD are unknown. We retrospectively analyzed the records of adult patients with IPD of the mucoid phenotype at Teine Keijinkai Hospital, Hokkaido, Japan, between 2009 and 2015. Seven patients（six males）with age range between 62 and 80 years were diagnosed as having mucoid IPD during the study period. Two patients had a history of malignancy and diabetes mellitus respectively,and six patients were living independently. No patients were previously vaccinated with pneumococcal vaccine. Six patients had clinical manifestations of pneumonia；one patient had multiple concomitant complications of mastoiditis, meningitis, and prosthetic joint infection. All isolates were isolated from blood. All isolates were susceptible to beta-lactam antibiotics, while six isolates were resistant to macrolides and chloramphenicol. Based on the Quellung reaction and real-time polymerase chain reaction（PCR）results, one isolate of mucoid phenotype was confirmed as serotype 3 with the penicillin binding protein gene of pbp2x and the macrolide resistant gene of ermB. Although all patients received appropriate antibiotics based on susceptibility testing, four patients required mechanical ventilation and vasopressors. One patient had neurological sequelae（hypacusis）and two patients died during the course of hospitalization. This case series suggests that mucoid IPD can occur in immunocompetent hosts and can cause high mortality. Since most of the mucoid phenotype of S. pneumoniae are serotype 3, widespread use of pneumococcal vaccine is important to prevent morbidity and mortality associated with IPD.

From April to May 2014, a total of seven cases of meropenem（MEPM）-resistant Escherichia coli were isolated from the sputum specimens in 7 different patients in a community hospital. The MICs of MEPM for isolates were 8 to 32μg/mL, whereas the MICs of imipenem（IPM）were 0.5μg/mL or 1μg/mL. All of the isolates possessed the metallo β-lactamase（MBL）IMP-6 gene, and were CTX-M 2 type extended-spectrum β-lactamase（ESBL）-producers. Pulsed-field gel electrophoresis（PFGE）patterns for the isolates were identical. At the time of specimen collection, one patient had been hospitalized for a long time and the other six patients had been comparatively recently admitted to the hospital. Of the six patients, two had been staying in the same nursing facility before admission, whereas the remaining 4 patients had no relationship with each other because they had been in separate locations. Thus, these cases were not considered to be nosocomially-acquired infection. Our findings suggest that MBL-producing E. coli has been spreading widely in the community such as in local nursing facilities.

7-valent pneumococcal conjugate vaccine（PCV7）has been included in the routine immunization schedule since April 2013 in Japan. Serotype replacement ―a phenomenon by which serotypes are replaced by non-vaccine serotypes after vaccine introduction ―has been reported in invasive pneumococcal disease （IPD）. Pneumococcus in sputum samples is one of the major causes of bronchopulmonary infection in children. We tried to verify whether serotype replacement of Pneumococcus occurs in sputum samples in a similar manner as in IPD. From August 2014 to September 2015, we performed antimicrobial susceptibility testing and serotyping of Streptococcus pneumoniae from sputum samples and investigated the history of PCV from hospitalized children with S. pneumoniae bronchopulmonary infection. From the results of our investigation, 80.3% of children have received PCV at least once. Serotypes of Pneumococcus were determined in 92.4% of tested strains and PCV13 strains accounted for only 9.8%. Major isolated serotypes were 15A（21.3%）, 35B（19.7%）, and 6C（13.1%）. Those were not included in PCV13,i.e. serotype replacement occurs in bronchopulmonary infection just as in IPD. The results of antimicrobial susceptibility testing for Penicillin G indicated that penicillin-resistant S. pneumoniae （PRSP）accounted for 4.5%, penicillin-intermediate resistant S. pneumoniae （PISP） accounted for 47.0% and penicillin-susceptible S. pneumoniae （PSSP） accounted for 48.5%. When examining the drug susceptibility by serotypes, 15A, 19A, 23A and 35B showed a high percentage of non-susceptibility. This means there is a difference in the resistant trend by serotypes. In our study, it became clear that verifying of the serotypes of Pneumococcus in sputum is meaningful and surveillance of serotypes is important for evaluation of vaccination as IPD.

The newly developed rapid diagnostic test （RDT, DK14-CA1, Denka Seiken Co., Ltd.） to detect Campylobacter antigen was evaluated using fecal specimens of patients with enteritis. The RDT is an immunochromatographic assay using colored latex and can detect Campylobacter antigen （C. jejuni and C. coli）from patientsʼ stool samples within 15 minutes. A total of 227 stool samples obtained from patients with enteritis were examined and the results were compared with conventional culture methods. Overall sensitivity, specificity, accuracy and positive predictive value（PPV）were 75.6%, 98.6%, 89.9% and 97.0% respectively. Among 53 severe cases defined with their clinical findings, sensitivity, specificity, accuracy and PPV were 82.1%, 100%, 90.6% and 100% respectively. Mean time to obtain the result with the RDT was 7 minutes whereas the culture method took 2.2 days. This study revealed the usefulness of the newly developed RDT as a rapid detection tool for Campylobacter antigen. Although the RDT has a little lower sensitivity compared with culture method, the simple and rapid test can contribute to treatment decisions for patients with enteritis and can be used at the patientʼs bedside and in outpatient clinics.

A 59-year-old male presented with fever, and was admitted for bacteremia due to gram-positive rod. All 5 sets of blood cultures obtained prior to the initiation of vancomycin tested positive for Bacillus subtilis. Based on the susceptibility test result, the antibiotics were changed to levofloxacin to complete a total of fourteen days treatment. The patient recovered without relapse over one year. Despite thorough examinations, the portal of entry of B. subtilis remained unclear. We retrospectively reviewed ten cases of bacteremia due to B. subtilis over 5 years in our hospital. The cases with positive B. subtilis blood cultures which were evaluated as contamination were excluded from the review. The most common portal of entry of B. subtilis was secondary bacteremia due to perforation or ileus （70%）, followed by an unknown site（30%）. B. subtilis should be considered not only as a contaminant but also as a true pathogen of bacteremia.

A 71-year-old woman who was undergoing immunosuppressive therapy presented with a 7-day history of productive cough and 2-day history of fever. She was diagnosed with severe pneumonia and septic shock. Meropenem, azithromycin, large amounts of fluids, and noradrenaline were administered, and high-flow nasal cannula oxygen therapy was provided. The gross appearance of the aspirated sputum was ginger-like,and the gram-positive cocci in chains were identified as group A beta-hemolytic streptococci (GAS), Streptococcus pyogenes. The blood sample culture test revealed negative results. Based on Stevensʼ criteria, the patient was finally diagnosed as having streptococcal toxic shock syndrome (STSS). Antibiotics were switched to ampicillin/sulbactam and clindamycin as an antitoxin treatment, and the patient was discharged on day 33.　Serotypes of GAS were T1, M1, and emm1. Superantigens spe A, spe B, and spe F were present, and spe C was absent. These observations were compatible with the clinical features of hypotension. GAS is an uncommon cause of community-acquired pneumonia, which when potentially complicated with STSS can lead to a high mortality rate, and the rapid progression is particularly a striking feature. We should be aware that GAS can cause pneumonia, and antitoxin treatment can play a key role in STSS management.

Acute retinal necrosis（ARN）is an infectious retinitis caused by varicella zoster virus（VZV）, herpes simplex or cytomegalovirus. Without systemic therapy, ARN may progress bilaterally in seventy percent of unilateral patients. A 38-year-old-man was admitted to our hospital with Hodgkinʼs lymphoma and hemophagocytic lymphohistiocytosis. During the chemotherapy, left facial herpes zoster developed. He received valacyclovir for 14 days. After improvement of the blisters, he continued acyclovir as secondary prophylaxis. Three weeks after the facial zoster, sudden visual loss in the left eye occurred. ARN induced by VZV was diagnosed with ophthalmoscopy and the polymerase chain reaction test of the anterior chamber. Because continuous chemotherapy for Hodgkinʼs lymphoma was needed, he continued valacyclovir as secondary prophylaxis for 6 months and he accomplished the chemotherapy without contralateral progression. Our case suggested the utility of valacyclovir for secondary prophylaxis. Further experiments would be required to establish secondary prophylaxis in immunocompromised patients.

We herein report on a case of Vibrio vulnificus infection that was improved by conservative treatment in Kagoshima, Japan. A 75-year-old Japanese woman with liver cirrhosis presented to our hospital with shaking chill and right lower leg pain. Her blood culture was positive for V. vulnificus, and bullae had newly appeared on the right leg. Further history taking revealed that she had eaten some raw seafood before admission. She recovered following administration of antibiotics and small incisions in the lesion. West Japan（especially, the northern parts of Kyushu island）is well known as an endemic area ofV. vulnificus infection：however, some cases had been reported in other areas in Japan. When clinicians treat cellulitis with risk factors,we should consider the possibility of V. vulnificus infection, even in a non-endemic area. Taking blood culture and early administration of appropriate antibiotics may contribute to conservative cure of some case of V. vulnificus infection.