Nationwide surveillance of bacterial pathogens isolated from children conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2017: General overview of pathogenic antimicrobial susceptibility.

A nationwide surveillance of the antimicrobial susceptibility of pediatric patients to bacterial pathogens was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in Japan in 2017. The isolates were collected from 18 medical facilities between March 2017 and May 2018 by the three societies. Antimicrobial susceptibility testing was conducted at the central laboratory (Infection Control Research Center, Kitasato University, Tokyo) according to the methods recommended by the Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 926 strains (331 Streptococcus pneumoniae, 360 Haemophilus influenzae, 216 Moraxella catarrhalis, 5 Streptococcus agalactiae, and 14 Escherichia coli). The ratio of penicillin-resistant S. pneumoniae was 0% based on CLSI M100-ED29 criteria. However, three meropenem or tosufloxacin resistant S. pneumoniae isolates were obtained. Among H. influenzae, 13.1% of them were found to be ß-lactamase-producing ampicillin resistant strains, while 20.8% were ß-lactamase non-producing ampicillin-resistant strains. No capsular type b strains were detected. In M. catarrhalis, 99.5% of the isolates were ß-lactamase-producing strains. All S. agalactiae and E. coli strains were isolated from sterile body sites (blood or cerebrospinal fluid). The ratio of penicillin-resistant S. agalactiae was 0%, while that of extended spectrum ß-lactamase-producing E. coli was 14.3%.

Molecular epidemiology, antimicrobial susceptibility, and characterization of macrolide-resistant Streptococcus pyogenes in Japan.

Here we report the molecular epidemiology of macrolide-resistant Streptococcus pyogenes (group A streptococci, GAS) isolated from children with pharyngotonsillitis between 2011 and 2013 in Japan. In 299 isolates, 124 (41.5%) isolates were macrolide-resistant. We characterized the isolates by emm typing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Of 299 isolates, 124 (41.5%) were macrolide-resistant isolates, 76 (61.3%) possessed mefA and 46 (37.1%) possessed ermB. All 76 isolates with mefA possessed msrD. There were no isolates possessed ermTR in this study. Eight emm/MLST types were observed. The predominant type was emm1/ST28 (57 isolates, 46.0%), which possessed the mefA/msrD complex, presenting as the M phenotype. The second most predominant type was emm12/ST467, which possessed ermB, presenting as the cMLSB phenotype. Of the cMLSB phenotype isolates, types emm28/ST52 and emm12/ST36 had multiple genetic backgrounds. We found high proportions of macrolide-resistant GAS in the southwestern areas of Japan.

Clinical evaluation of a new rapid immunochromatographic test for detection of Bordetella pertussis antigen.

A more rapid and less complicated test to diagnose pertussis is required in clinical settings. We need to detect Bordetella pertussis, which mainly causes pertussis, as early as possible, because pertussis is more likely to become severe in infants, and people around them can easily become a source of infection due to its strong infectivity. Nevertheless, methods that can detect B. pertussis rapidly and efficiently are lacking. Therefore, we developed a new immunochromatographic antigen kit (ICkit) for the early diagnosis of pertussis. The ICkit detects B. pertussis antigens in a nasopharyngeal swab without equipment and provides the result in about 15 min with a simple procedure. Additionally, a prospective study to evaluate the ICkit was conducted in 11 medical institutions, involving 195 cases with suspected pertussis. Compared with the real-time polymerase chain reaction (rPCR), the sensitivity and specificity of the ICkit were 86.4% (19/22) and 97.1% (168/173), respectively. The ICkit detected the antigen in both children and adults. Furthermore, the ICkit detected the antigen until the 25th day from the onset of cough, when rPCR detected the antigen. Thus, the ICkit demonstrated a high correlation with rPCR and would help diagnose pertussis more rapidly and efficiently.

[Antibiotic therapy against acute tonsillopharyngitis in children due to group A beta-hemolytic streptococci: comparison of clinical efficacy, the bactericidal effects, and effects on oral flora between cefditoren pivoxil for 5 days and amoxicillin for 10 days].

We compared the clinical efficacy, the bactericidal effects, effect on the oral microbial flora, and adverse reactions between cefditoren pivoxil (CDTR-PI) for 5 days and amoxicillin (AMPC) for 10 days in children with acute group A beta-hemolytic streptococci (GAS) tonsillopharyngitis, and simultaneously examined the emm genotype and drug susceptibility of the isolated GAS. The results showed that the clinical efficacy was 100% for CDTR-PI and 97.9% for AMPC, with no difference between the two groups, and the bacterial elimination rate was 100% in both groups. No serious adverse event was noted in either group. On the other hand, concerning changes in the oral microbial flora between before and after treatment, the amount of bacteria showed no change in the CDTR-PI group (p = 0.5761) but clearly decreased in the AMPC group (p = 0.0049). This indicates that CDTR-PI does not disturb the oral microbial flora compared with AMPC. Also, the emm types determined in the 112 GAS strains isolated in this study were similar to those that have recently been isolated frequently in Japan. Concerning the drug resistance, none of the isolates showed resistance to beta-lactam antibiotics, but 45% of them were resistant to macrolides. The advantages of short-term treatment are considered to include a lower cost, improvement in drug compliance, decrease in the frequency of the occurrence of adverse reactions, decrease in the frequency of the appearance of drug-resistant strains, and alleviation of the psychological burden of patients and their parents. For these reasons, we conclude that CDTR-PI for 5 days is a useful option for the treatment of acute GAS tonsillopharyngitis in children.

Genotypes of macrolide-resistant pneumococci from children in southwestern Japan: raised incidence of strains that have both erm(B) and mef(A) with serotype 6B clones.

MICs of penicillin G, erythromycin, clarithromycin, clindamycin, azithromycin, and telithromycin were tested for 189 clinical isolates collected during 2002 to 2005 from children in southwestern Japan. Serotyping and polymerase chain reaction for presence of erm(B) and mef(A) were performed. All strains with erm(B) + mef(A) were analyzed by pulsed-field gel electrophoresis (PFGE) and compared to 3 global clones: Spain(23F)-1; Spain(9V)-3 and its variant -14; a South Korean strain same as Taiwan (19F)-14 clone and 5 strains with erm(B) + mef(A) from other countries. Of the 173 macrolide-resistant (erythromycin MIC > or =0.5 microg/mL) strains, 104 (60.1%) had erm(B), 47 (27.2%) had mef(A), and 22 (12.7%) had erm(B) + mef(A). Strains expressing erm(B) or both erm(B) and mef(A) had high macrolide MIC(90)s (>64 microg/mL), except telithromycin (MIC(90), 0.25 microg/mL). Of the 22 erm(B) + mef(A) strains, 10 had 4 distinct PFGE patterns and were mainly serotype 6B clones, which differed from those described in previous reports; 5 other strains had unique profiles.

Comparison of serological tests for detection of immunoglobulin M antibodies to Chlamydophila pneumoniae.

BACKGROUND AND OBJECTIVE: To evaluate an enzyme immunoassay (EIA) (AniLab C. pneumoniae) for detecting anti-Chlamydophila pneumoniae-specific IgM antibody, by comparing it with an ELISA, Hitazyme C. pneumoniae, and a micro-immunofluorescence (MIF) test. METHODS: Antibodies in sera from three groups of patients were measured: eight serum samples collected serially from a patient with acute C. pneumoniae pneumonia, 34 serum samples with Hitazyme-ELISA false-positive results, and 137 serum samples from patients with community-acquired pneumonia. RESULTS: The IgM antibody titre in the patient with acute C. pneumoniae pneumonia showed almost identical variation with the EIA, ELISA and MIF tests. Among the 34 samples found to be false-positive for IgM with ELISA, EIA revealed no positive cases. When a true positive case was defined as one for which a positive reaction was obtained with at least two tests, the sensitivities of the EIA, ELISA and MIF tests were 97.1%, 100% and 74.3%, with specificities of 100%, 37.3% and 100%, respectively. CONCLUSIONS: EIA was highly sensitive and specific as compared with the MIF test, and the ELISA test showed the lowest specificity. Consequently, the AniLab-EIA, rather than the Hitazyme-ELISA, is recommended as the routine method for accurately diagnosing acute C. pneumoniae infection.

[A case of bacterial meningitis due to Streptococcus bovis in an infant with normal cerebrospinal fluid findings at the first CSF examination].

Streptococcus bovis very occasionally causes rarely sepsis, endocarditis, and meningitis in newborns and the elderly. We report the case of infant meningitis caused by S. bovis despite normal cerebrospinal fluid (CSF) findings at the first CSF examination. A 77-day-old boy with 21-trisomy and patent foramen ovale and seen for a high fever underwent blood examination and lumbar puncture due to toxic appearance despite a lack of meningeal signs, and was admitted. His CSF findings were normal and he was given intravenous ceftriaxone against potential bacteremia. He had systemic seizures with continuous fever for 2 days after admission and a second CSF examination. Gram-positive coccus grew from his CSF at the first examination, and CSF cells from the second lumbar puncture increased to 4060/tL (86% neutrophils), so vancomycin was added against potential enterococcal meningitis. S. bovis was finally grown from the first CSF, ceftriaxone discontinued, and intravenous ampicillin added. He recovered after 20 days of antibiotic administration. S. bovis becomes a potential pathogen for meningitis in infants, and must be considered as a cause of meningitis despite its very rarity. CSF findings at the first lumbar puncture may be normal for meningitis in newborns and infants at the first CSF examination, so we must be very careful in the diagnosis of bacterial meningitis even with normal CSF findings, and considered antibiotic treatment against potential bacterial meningitis.

[Dipylidium caninum infection in an infant].

Dipylidium caninum, the dog tapeworm, is a common intestinal cestode of domestic dogs and cats, but few cases have been reported of human infection by this parasite in Japan. We repot a case of D. caninum infection in a 17 month-old girl, who sometimes had symptoms of abdominal pain, diarrhea, and dysphoria at night. Her mother noted the appearance of small white worms in her stool, and she was seen by a local pediatrician. Despite antiparasitic therapy wiht pyrantel pamoate, the problem persisted and was eventually referred for further workup to Kurume University Hospital. The diagnosis was made by microscopic examination of the excreted proglottids, which contained characteristic egg capsules. She was successfully treated with a singledose of praziquantel and four adult parasites were recovered. The longest intact worm was 32cm. Her family had household pets (a dog and a cat). The pets were seen by the local veterinary and both were evidenced D. caninum. Humans, primarily children, become infected when they accidentally ingest fleas. Parents usually find proglottids as multiple white objects, often described as cucumber, melon, or pumpkin seeds, in stool, diapers, or on the perineum. Most general practitioners and pediatricians may treat children with enterobiasis (pinworm) infection, and in case the treatment fails, other parasite infection should be considered such as this worm. A history of dog or cat pets, fleas, and flea bites may be important clues to diagnosis. Pets found to be infected should also be treated.

[Antibody titers against measles, rubella, mumps and varicella-zoster viruses in medical students].

It is important to identify and immunize susceptible students who have clinical practice to prevent and control hospital infections. The antibody titers to measles, rubella, mumps and varicella viruses were measured in 1,139 students(417 men, 722 women, average age 21.3+/-2.7 yr old)including 510 medical students, 442 nursing students and 187 students of the School of Medical Technology in Kurume University. Antibodies against measles virus were detected by particle agglutination assay(PA), those against rubella virus by hemagglutination inhibition assay(HI), and those against mumps and varicella viruses by enzyme-linked immunosorbent assay(EIA). The serological susceptibilities to measles, rubella, mumps and varicella viruses were 112(9.8%), 112(9.8%), 163(14.3%)and 73(6.4%), respectively. The serological susceptibilities to measles, rubella and mumps viruses in male students were not different from those in female students. The susceptibility to varicella virus in female students was significantly higher than that in male students. After susceptible students were recommended to have vaccinations against each virus, the vaccination rate of the students without antibody was 99.1%. The history of infection and vaccination against the viruses were examined by self-recorded questionnaires in 406 students from all disciplines. The serological susceptibility of students with positive vaccination history was 11.1% for measles, 6.8% for rubella, 18.3% for mumps, and 4.9% for varicella. The serological susceptibility of students with a positive infection history was 5.7% for measles, 3.4% for rubella, 2.9% for mumps, and 4.9% for varicella. In the self-recorded questionnaire, the rate of unknown infection and vaccination histories were 57.5% and 71.6% for measles, 52.5% and 68.4% for rubella, 34.3% and 75.6% for mumps, and 27.1% and 80.5% for varicella, respectively. In conclusion, these data confirm that it is essential to assess immune status against measles, rubella, mumps and varicella in students who have clinical practice in hospital regardless of infection or vaccination history. Accordingly, susceptible students should be vaccinated to prevent those viral infections in hospital.

Outbreak of Chlamydia pneumoniae infection in a Japanese nursing home, 1999-2000.

OBJECTIVE: To identify risk factors for infection and severe illness due to Chlamydia pneumoniae. METHODS: To identify risk factors for infection, we conducted a case-control study among nursing home residents who had onset of symptoms during December 1, 1999, to February 20, 2000. To identify risk factors for severe illness among nursing home residents, we conducted a retrospective cohort study. SETTING: A nursing home providing long-term and day care services for elderly patients in Japan.Participants. Fifty-nine residents and 41 staff members of a nursing home. RESULTS: The attack rates for respiratory illness were 53% (31 of 59) among residents and 22% (9 of 41) among staff. Infection was confirmed in 15 resident and 2 staff case patients by isolation of C. pneumoniae from nasal swab specimens. Fifteen resident case patients developed severe illness (ie, bronchitis, pneumonia, and hypoxia); one case patient died. The median age of resident case patients was 87 years. We could identify neither the source of the outbreak nor significant risk factors for infection and severe illness in residents. However, residents with a higher level of physical activity were more likely to become infected, whereas older residents (aged more than 85 years) and those with a lower level of physical activity were more likely to develop severe illness (P>.05). Contact with residents was a risk factor for infection in staff (relative risk, undefined; P=.04). CONCLUSIONS: C. pneumoniae can cause large outbreaks of infection and severe illness among elderly persons, and its transmission is likely to be enhanced by close contacts among people in nursing homes. Therefore, early detection of an outbreak by means of better surveillance, and subsequent isolation of patients, may be effective control measures.

Serologic response after vaccination against influenza (A/H1N1)pdm09 in children with renal disease receiving oral immunosuppressive drugs.

A limited number of reports are available regarding the effect of the influenza vaccine in pediatric patients receiving steroid and immunosuppressant therapy. The influenza A(H1N1)pdm09 vaccine was administered to 15 children with renal disease who were receiving steroid and immunosuppressant therapy (treatment group) and 23 children with who were not receiving these drugs (non-treatment group). Titer transition of the hemagglutination inhibition antibody was compared between the 2 groups immediately before vaccination and 4 weeks and 6 months after vaccination. Multivariate analysis showed a significant correlation between geometric mean titer, SCR, and SPR with age, while no correlation was observed between treatment with immunosuppressant therapy and efficacy. No serious adverse reactions occurred after vaccination. This strain is not present in existing influenza vaccines, and A(H1N1)pdm09HA vaccination was administered alone in 2009. The children in this study had not previously been exposed to this strain. Therefore, we evaluated the effect of the A(H1N1)pdm09HA vaccine without the effects of vaccination or past infection with A(H1N1)pdm09HA or A(H3N2) vaccination in the previous year.

New application of terahertz time-domain spectrometry (THz-TDS) to the phonon-polariton observation on ferroelectric crystals.

A new instrument for terahertz time-domain spectroscopy (THz-TDS) has been developed. It consists of a composite THz-TDS system and a high throughput (Martin-Puplett) interferometer. The instrument is for use in the qualitative study of optoelectronic constants of materials. The spectral transmission intensity and phase shift related to phonon-polariton dispersion have been measured between 100 cm(-1) and 3 cm(-1) on ferroelectric crystals of industrial interest. These include bismuth titanate Bi4Ti3O12 (a key material for FeRAM), lithium niobate LiNbO3 (a typical nonlinear crystal for parametric oscillator applications) and lithium heptagermanate Li2Ge7O15 for surface elastic wave filter applications. The complex dielectric constants are well reproduced by the phonon-polariton dispersion relation based on the Kurosawa formula. The instrument details and phonon-polariton dispersion results are described.

Rapid and simple diagnosis of Chlamydophila pneumoniae pneumonia by an immunochromatographic test for detection of immunoglobulin M antibodies.

To evaluate a newly developed immunochromatographic test (the MySet test) for the detection of Chlamydophila pneumoniae-specific immunoglobulin M antibodies, the results obtained by the MySet test were compared with those obtained by two serological tests. The sensitivity and specificity of the MySet test were 100% and 92.9%, respectively. The MySet test is rapid and simple to use and is thought to be a useful tool for the selection of appropriate antibiotic therapy.