Clinical aspects of invasive infections with Streptococcus dysgalactiae ssp. equisimilis in Japan: differences with respect to Streptococcus pyogenes and Streptococcus agalactiae infections.

Streptococcus dysgalactiae ssp. equisimilis (SDSE) is increasingly being identified as a pathogen responsible for invasive and non-invasive infections. We compared the clinical features of invasive SDSE infections with those of invasive infections caused by Streptococcus pyogenes (group A streptococcus (GAS)) and Streptococcus agalactiae (group B streptococcus (GBS)). Active surveillance for invasive SDSE, GAS and GBS was maintained over 1 year at 142 medical institutions throughout Japan. Clinical information was collected together with isolates, which were characterized microbiologically. Two hundred and thirty-one invasive SDSE infections were identified, 97 other patients had infections with GAS, and 151 had infections with GBS. The median age of the SDSE patients was 75 years; 51% were male and 79% had underlying diseases. Forty-two SDSE patients (19%) presented to the emergency department. Among the 150 patients (65%) for whom follow-up was completed, 19 (13%) died and eight (5%) had post-infective sequelae (poor outcome). Insufficient white blood cell responses (<5000 cells/microL) and thrombocytopenia on admission each suggested significantly higher risk of poor outcome (ORs 3.6 and 4.5, respectively). Of 229 isolates, 55 (24%) showed an stG6792 emm type, which was significantly associated with poor outcome (OR 2.4). Clinical manifestations of invasive SDSE infections were distinct from those of invasive GBS infections. Primary-care doctors should consider invasive SDSE infections when treating elderly patients.

Serotype and antibiotic resistance of isolates from patients with invasive pneumococcal disease in Japan.

Invasive pneumococcal disease (IPD) is of concern in Japan, where the heptavalent pneumococcal conjugate vaccine (PCV7) is unavailable. We determined serotypes, genotypes indicating beta-lactam resistance, and antibiotic susceptibilities of 496 isolates from normally sterile sites in patients (193 children, 303 adults) from 186 institutions between August 2006 and July 2007. Disease presentations included sepsis (46.2%), pneumonia (31.5%), and meningitis (17.5%). Mortality was 1.4% in children and 22.1% in adults, many of whom had underlying diseases. In children, serotype 6B (22.5%) was followed by 19F (14.1%), and 14 (13.1%); potential coverages of PCV7 and PCV13 were 75.4% and 93.7%, respectively. In adults, serotype 12F (14.3%) was followed by 3 (11.3%), and 6B (10.3%); 23-valent polysaccharide vaccine (PPV23) coverage was 85.4%. Most serotype 12F strains were gPISP, with pbp2b gene alteration; carbapenem had an excellent MIC90. PCV7 is recommended for children and PPV23 for adults to increase prevention against IPD.

A foodborne outbreak of a group A streptococcal infection in a Japanese university hospital.

We describe an outbreak of foodborne tonsillopharyngitis caused by group A streptococcus (GAS), a rarely reported event that occurred during a campus orientation meeting in Japan. Of 461 students and staff members who had eaten boxed lunches during a meeting at Kitasato University, 298 developed sore throat and/or fever, and 285 underwent medical examination. Amoxicillin was prescribed when throat culture specimens yielded GAS. The attack rate was 64.6%. T-25 GAS was isolated from 150 examined persons. Of 65 patients who received amoxicillin for 3 days, GAS was eradicated before the first follow-up throat culture in 46 (70.8%) cases. Susceptibility was demonstrated to penicillins, cephalosporins, and macrolides in 86 GAS isolates obtained more than once from a given patient. GAS strains isolated at various time points were indistinguishable by pulsed-field gel electrophoresis (PFGE), and prtF1 was present. GAS strains were often difficult to eradicate because of a short initial treatment period, patient compliance problems, and the presence of prtF1.

Double-blind comparative study on the care of the neonatal umbilical cord using 80% ethanol with or without chlorhexidine.

We conducted a double-blind comparative study on the effectiveness of 80% ethanol (EtOH), with or without chlorhexidine (CHD), in the prevention of neonatal umbilical colonization by Staphylococcus aureus, the most frequently isolated pathogen on the neonatal umbilicus in the early period. A total of 100 neonates born at the National Tokyo Medical Centre from March to May 2000 and nursed at a maternity ward were enrolled. Forty-eight were randomly allocated to the group for whom umbilical cord disinfection was performed using 80% EtOH containing 0.5% CHD (CHD group) and 52 to disinfection with 80% EtOH alone (EtOH group). The mothers of the neonates and the nursing staff were unaware as to which disinfectant was being used. Disinfection of the umbilicus and the surrounding area was done immediately after birth and twice daily thereafter, after bathing and in the evening, throughout the hospitalization period. Specimens for bacterial culture were taken from the umbilical cord and surrounding skin on day 4 or 5 after birth. As a disinfectant susceptibility test, we checked the minimum killing concentration (MKC) of CHD and EtOH. There was no statistically significant difference between the two groups with respect to sex, gestation period, birthweight, APGAR score or delivery method. In the CHD group, S. aureus was isolated from 25% of the patients, while it was isolated from 57.7% in the EtOH group (P<0.001). In the CHD group, 50% of the S. aureus strains were MRSA, compared with 73.3% in the EtOH group (non-significant). All the S. aureus strains were killed by the combination of both CHD and EtOH at the concentrations used. In terms of the MKC90, there was no significant difference between the CHD group and the EtOH group. For the daily care of the neonatal umbilicus, disinfection using 80% EtOH containing CHD was found to be more effective than that using 80% EtOH alone in preventing colonization by S. aureus.

[An epidemiological study for fungus isolation during the twenty-five year periods from 1976 to 2000 in Kitasato University Hospital].

We investigated an epidemiological study for fungus isolation in our hospital from 1976 to 2000. For 25 years, the total sample number of fungus examination were 64,296, and after 1988, the total sample number increased suddenly. As a whole, the positive ratio was constantly about 40%. When our hospital opened, the obstetrical and gynecological samples showed 38.8% for fungus examination, but recently, samples of the respiratory organ has increased. Ratio of isolation for yeast, Candida albicans was 53.8%, and another yeasts such as Candida glabrata, Candida tropicalis, Candida parapsilosis were 12.5%, 5.3%, and 3.4%, respectively. Recently, isolation of Candida glabrata showed a tendency to increase. For genus Aspergillus, Aspergillus fumigatus was isolated, 48.1%, and Aspergillus nigar, Aspergillus terreus were isolated, 31.4% and 7.5%, respectively. For dermatophytes, Trichophyton rubrum was isolated, 63.6% indermatophytes, and another dermatophytes were Microsporum canis (17.9%), and Trichophyton mentagrophytes (15.9%), respectively. For dermatophytes, isolation of Microsporum canis showed a tendency to increase. Recently, the plural number of species showed a tendency to increase in the samples. Compared with the number of samples at the beginning in our hospital, the plural number of species in the samples increased about six times.

[Investigation of infective endocarditis clinical isolates of methicillin resistant Staphylococcus aureus non-responsive to vancomycin].

Methicillin resistant Staphylococcus aureus (MRSA) is one of the most important strains which induce hospital and post-operative infection. In cases of infective endocarditis in which VCM was not efficacious, MRSA strains were chronologically isolated at three different times and examined with the following parameters: minimum inhibitory concentration (MIC), fractional inhibitory concentration (FIC) index, Mu 3 agar, population analysis, pulse field gel electropholesis (PFGE). The PFGE banding patterns of the three MRSA isolates were the same, therefore, it was concluded that the same strain of MRSA was selected for reduced susceptibility. A pattern of Mu 3 and Mu 50 was demonstrated under population analysis.

Association of amino acid substitutions in penicillin-binding protein 3 with beta-lactam resistance in beta-lactamase-negative ampicillin-resistant Haemophilus influenzae.

The affinity of [(3)H]benzylpenicillin for penicillin-binding protein (PBP) 3A was reduced in 25 clinical isolates of beta-lactamase-negative ampicillin (AMP)-resistant (BLNAR) Haemophilus influenzae for which the AMP MIC was > or =1.0 microg/ml. The affinities of PBP 3B and PBP 4 were also reduced in some strains. The sequences of the ftsI gene encoding the transpeptidase domain of PBP 3A and/or PBP 3B and of the dacB gene encoding PBP 4 were determined for these strains and compared to those of AMP-susceptible Rd strains. The BLNAR strains were classified into three groups on the basis of deduced amino acid substitutions in the ftsI gene, which is thought to be involved in septal peptidoglycan synthesis. His-517, near the conserved Lys-Thr-Gly (KTG) motif, was substituted for Arg-517 in group I strains (n = 9), and Lys-526 was substituted for Asn-526 in group II strains (n = 12). In group III strains (n = 4), three residues (Met-377, Ser-385, and Leu-389), positioned near the conserved Ser-Ser-Asn (SSN) motif, were replaced with Ile, Thr, and Phe, respectively, in addition to the replacement with Lys-526. The MICs of cephem antibiotics with relatively high affinities for PBP 3A and PBP 3B were higher than those of AMP and meropenem for group III strains. The MICs of beta-lactams for H. influenzae transformants into which the ftsI gene from BLNAR strains was introduced were as high as those for the donors, and PBP 3A and PBP 3B showed decreased affinities for beta-lactams. There was no clear relationship between 7-bp deletions in the dacB gene and AMP susceptibility. Even though mutations in another gene(s) may be involved in beta-lactam resistance, these data indicate that mutations in the ftsI gene are the most important for development of resistance to beta-lactams in BLNAR strains.

Population pharmacokinetics of panipenem in neonates and retrospective evaluation of dosage.

The population pharmacokinetics of panipenem was studied in 23 neonates. Their postconceptional age (PCA) was 24.7-42.6 weeks and their body weight was 530-4455 g at initiation of therapy. Panipenem was infused over a period of 60 min in a dose of 10.2-34.7 mg/kg bd in 21 patients, tid in one patient and four times daily in one patient for a mean of 10.7 days. Blood samples were obtained just before the infusion and 1-2 h after and again 6 h after the infusion. All the data for the 108 serum panipenem concentrations were evaluated with a non-linear mixed-effect model (NONMEM with first-order method), a computer program designed for population pharmacokinetic analysis. One- and two-compartment population pharmacokinetic parameters were measured. The two-compartment parameters were as follows: panipenem clearance CL = 0.150 L/h, central volume of distribution = 0.54 L, intercompartmental clearance = 0.014 L/h and peripheral volume of distribution = 0.28 L. The one-compartment parameters were CL = 0.175 L/h and volume of distribution = 0.55 L. In the fitting process using the one-compartment model, significantly fixed effects related to CL were PCA, postnatal age (PNA), gestational age (GA), body weight (BW) and serum creatinine, and that for the distribution volume (V) was BW. CL showed a logarithmic rise with PCA (CL = 0.00176 x exp(0.14 x PCA)). The CL levels in the patients with PCA < 33 weeks (0.098 L/h) were significantly lower (P < 0.001) than those with PCA > or = 33 weeks (0.25 L/h). The final formulae for the population pharmacokinetic parameters are as follows: CL = 0.0832 (PCA < 33 weeks), CL = 0.179 x BW (PCA > or = 33 weeks), V = 0.53 x BW (coefficient of variation; 23.9% for CL, 28.5% for V). Based on these data, a simulated time-concentration curve was compared with that for adult data in a clinical Phase I study. Our findings suggest that the panipenem dosage regimen of 10-20 mg/kg every 12 h should yield concentrations within the accepted therapeutic range.

[The trend of childhood bacterial meningitis in Japan (1997.7-2000.6)].

We surveyed the epidemiology of purulent meningitis in pediatrics for 3 years between July 1997 and June 2000 in Japan and obtained the following results. The number of cases of purulent meningitis was 428, which was equivalent of 1.1-1.7 children out of 1,000 hospitalized those in pediatrics per year. The age-distribution for the infections was the highest under 1 year of age and it decreased as the age increased. Under 1 year of age, the highest distribution was observed in one month of age and under 1 month of age, the highest distribution was observed in 7 days of or younger ages. Haemophilus influenzae was the most common pathogen causing the infections, followed by Streptococcus pneumoniae, group B streptococcus, and Escherichia coli. Relationship between causing pathogens and age-distribution was as follows: group B streptococcus and E. coli were major pathogens under 4 months of age and H. influenzae and S. pneumoniae were major pathogens over 3 months of age. Susceptibility tests performed at each facility demonstrated that 25.3% of H. influenzae isolates and 38.7% of S. pneumoniae isolates were drug-resistant. Analysis of resistant genes for H. influenzae and S. pneumoniae isolates, which were stored and sent, demonstrated higher rates of resistance than those observed in susceptibility tests. These results suggest that the increase in insufficient efficacy of usual treatment with combination of ampicillin and cefotaxime is predictable against the infections. Therefore, the treatment for the infections should be reconsidered.

[Antibacterial activity of fosfomycin against the causative bacteria isolated from bacterial enteritis].

The in vitro antibacterial activities of fosfomycin (FOM) and 3 fluoroquinolones against Salmonella spp., pathogenic Escherichia coli, Campylobacter spp. and Shigella spp. were investigated. The activity upon the environmental condition in the inflammation was compared with standard condition in vitro. On standard condition, the MIC90 of tosfloxacin (TFLX), norfloxacin (NFLX) and levofloxacin (LVFX) against E. coli (77 strains), Shigella spp. (50) and Salmonella spp. (41) were < or = 0.025-0.10, 0.10, and 0.05 microgram/ml, respectively. The MIC90 of FOM against those organisms was 0.39-1.56 micrograms/ml. The MIC90 of TFLX, NFLX, LVFX against Campylobacter spp. were 6.25, 100 and 3.13 micrograms/ml, respectively. The MIC90 of FOM was 50 micrograms/ml. The activity of FOM was unaffected by pH and in anaerobic condition. On the other hand, the activity of NFLX was decreased in low pH and in anaerobic condition. In the presence of horse blood and addition of Na+, the activities of both agents were unaffected. These results suggested that FOM is equally active with or superior to fluoroquinolone in the intestinal infection treatment.

[Pharmacokinetics of panipenem in neonates and dosage recommendation].

The pharmacokinetics of panipenem/batamipron (Carbenin; PAPM/BP) was studied in 17 neonates of the postconceptional age (PCA) of 25.6 to 43.1 weeks. PAPM/BP was administered at 10 mg/kg to 20 mg/kg every 12 hours over 60 minutes by intravenous infusion. Blood samples were obtained just prior to the infusion, one or two hours and six hours after the infusion. All the data for the 85 serum PAPM concentrations were analyzed by one-compartment model using a nonlinear mixed-effect model (NONMEM). The pharmacokinetic parameters in these population are given below: CLPAPM; 0.239 +/- 0.206 (L/hr), VdPAPM; 0.97 +/- 0.80 (L), Half Life; 3.1 +/- 0.5 (hr). Half life in the patients with PCA < 34 (2.66 +/- 0.44 hr) were significantly lower (p < 0.001) than that with PCA > or = 34 (3.39 +/- 0.23 hr). Our results suggest that postnatal alterations in the PAPM excretion are related to maturational changes in the renal function and that we should consider the values of PCA when determining the initial PAPM/BP dosing regimen in neonates. We conclude that the dosage of 10 mg/kg to 20 mg/kg every 12 hours are adequate treatment for neonatal infectious disease.

[Comparison of the morphology and the reactivity of Chlamydia pneumoniae isolated in north-Kanto Area, Ibaraki Prefecture, Japan].

To compare the morphology among Chlamydia pneumoniae (C. pneumoniae), strain TW183 and strains which were isolated in the area of Kasumigaura, Ibaraki from 1992 to 1995. C. pneumoniae were infected on HL cell monolayers and cultured in 5% CO2 at 35.5 degrees C for about 60 hrs. The cells were harvested and fixed with 2.5% glutaraldehyde, and then the regular procedure for observation of Chlamydia in inclusion by transmission electron microscope was performed. Immunoblot assay was carried out by using highly and partially purified C. pneumoniae TW183 and 4 isolates with partial purification as antigens. The results were as follows: the shape of TW183 and the isolates included pear and round shapes, respectively. Immunoblotting profiles were the same in terms of band-formation patterns with the serum from a patient infected with C. pneumoniae. These results may indicate that the round shape of C. pneumoniae elementary body (EB) is predominantly pandemic in Japan, although pear-shaped EBs of C. pneumoniae were found in the neighboring prefecture of Chiba.

[Summary of the clinical studies with azithromycin in the pediatric fields].

The clinical studies with azithromycin fine granules and capsules were conducted during the period from March 1993 to October 1994. Cmax's in 16 patients who received 10 mg/kg fine granules, were 0.29 +/- 0.24 microgram/ml, T1/2's were 42.0 +/- 11.8 hours, and AUC 0 approximately infinity's were 10.72 +/- 5.00 micrograms.hr/ml. The clinical results for azithromycin fine granule and capsules 10 mg/kg once daily for 3 days are as follows. The efficacy rate of fine granules, combining both "Excellent" and "Good", for pneumoniae where causative pathogenes were identified, was 95.3%, and for those which had failed to respond to previous chemotherapies, was 94.6%, respectively. The efficacy rate of capsules for 3 to 5 days was 100% in 40 cases where causative pathogenes were identified. Adverse reactions were found in 2.5%(fine granules) and in 5.4%(capsules) in cases eligible for evaluation. Abnormal changes in laboratory test were as follows: decrease of WBC by 5.6%(fine granules) and 9.3%(capsules) and increase in eosinophils by 7.1%(fine granules) and 11.4% (capsules). 59.8% of the patients claimed that the azithromycin 10% fine granules product was "easy to take". The result of a questionnaire on parents' demand on the improvement of antibiotics, showed that most concern was on the drug frequency(preferably once or twice daily) and the drug administering period(preferably short: 3 days). With regard to the efficacy, safety and compliance, it can be concluded that Azithromycin is one of the useful therapeutic regimens in the treatment of pediatric infections.

[Detection of anti-Chlamydia trachomatis antibody by means of enzyme immunoassay using synthetic peptide antigen].

Newly developed diagnostic kits for the detection of Anti-Chlamydia trachomatis, Peptide-Chlamvdia (LOY: Meiji Milk Products Co., Ltd., Tokyo; for IgG and IgA), were evaluated using the microimmunofluorescence assay (MIF) as the gold standard. These results were also compared to results of testing by Sero-IPALISA and immunoblot (I-B). Detection by LOY in based on enzyme immunoassay with synthetic peptides as the antigen. Thirty serum samples from pediatric patients and 130 serum samples from gynecology patients were used. All 26 pediatric samples that were positive for Chlamydia pneumoniae IgG antibody tested negative with LOY, indicating that the presence of the antibody against C. pneumoniae did not affect the assay by LOY. For 90 gynecological samples, the total, the positive and the negative agreement rates for IgG were quite high; i.e. 87.8%, 90.0% and 70.0% (LOY vs MIF), 85.6%, 85.0% and 90.0% (Sero-IPALISA vs MIF), and 92.0%, 94.9% and 70.0% (I-B vs MIF), respectively. On the other hand, many cases of MIF (-) and LOY (+) discrepancy were seen in IgA detection. In order to better understand the basis for such disagreement. 34 serum samples were collected from patients whose cervical samples were negative for the Chlamydia group antigen based on the assay with IDEIA-Chlamydia. They were then assayed by MIF and LOY. The total, the positive and the negative agreement rates for IgG were 91.2%, 100% and 90.9%, while the total and the negative agreement rates for IgA were 88.2% and 88.2% (there were no IgA positive cases). Furthermore, 6 serum samples (1 case of MIF (+) LOY (+) and 5 cases of MIF (-) LOY (+)) were provided to determine whether LOY detects C. trachomatis specific IgA antibody. Increasing amounts of C. trachomatis serovar L2 were added to the serum samples resulting in a progressive decrease in their reactivity in the LOY assay. These results lead us to speculate that LOY can reveal even low levels of C. trachomatis specific IgA antibody. In conclusion, LOY can be used as an useful kit for detecting C. trachomatis antibody.

[Influence of dexamethasone on the clinical course of bacterial meningitis in children. Especially on secondary fever. Experiences in 27 institutions].

Of pediatric patients with purulent meningitis seen at the institutions listed in the title page of this paper between 1986 and 1994, 93 patients treated with antibiotics and dexamethasone (DXM) were compared with 91 patients treated with antibiotics alone. The patients receiving antibiotics with dexamethasone achieved overall improvement in inflammatory symptoms and signs and cerebrospinal fluid findings and became afebrile significantly earlier than those receiving antibiotics alone. However, some of the patients became febrile again. The secondary fever rate for the DXM group was much higher than that for the antibiotic alone group (p < 0.0001). In most of the rebounded cases, the body temperature rose above 38 degrees C and remained elevated for 2-4 days. Cerebrospinal fluid (CSF) was cultured daily in 54 and 32 patients receiving antibiotics with and without DXM, respectively. Although this study was not a controlled study in a strict sense, these patients compared. In both groups, the CSF became mostly culture-negative within 48 hours. In a few patients receiving DXM, however, it became culture-negative after 72 hours or longer. DXM caused an adverse effect in a patient with meningitis caused by Streptococcus pneumoniae. The adverse effect was mild gastrointestinal bleeding, which recovered spontaneously. From the findings described above, the use of DXM combined with antibiotic therapy was considered to accelerate the relief from fever and improvement of inflammatory symptoms and signs and CSF findings. The body temperature rose again in more than half of the patients receiving DXM, but fell to normal spontaneously without treatment. The elevation doubtlessly could not be distinguished from recurrence of the meningitis itself or complications. It seems to be likely that no treatment but careful observation is required even if the fever recurs as far as the CSF findings showed favorable progress with excelluent general conditions. When DXM is given, it is essential that CSF tests and culture are repeated during the early stages and the progress is monitored carefully.

[Effect of antibiotics and antibody on phagocytic bactericidal activity of polymorphonuclear neutrophils of Bordetella pertussis].

The phagocytic bactericidal activity of the polymononucler neutrophils (PMNs) that were collected from healthy volunteer with and without antibody against Bordetella pertussis was investigated. Furthermore, these activity against B. pertussis under observing penicillins or macrolides antibiotics was investigated. Although no efficacy to B. pertussis strain by the PMNs in serum without antibody, but the viable cells of B. pertussis decreased to 1/1,000 1 hr after incubation and was not detected after 4 hrs. In particular, the viable cells of B. pertussis by the PMNs in serum with antibody was markedly reduced when azithromycin was present. These results suggests that the synergistic action of macrolide antibiotics and antibody-mediated phagocytic bactericidal activity on B. pertussis may have clinical relevance.

[Clinical evaluation of faropenem against infections in pediatric fields].

The recent increases in the prevalence of penicillin-resistant Streptococcus pneumoniae becomes a point at issue clinically. We carried out a clinical study in 40 cases in the pediatrics department, as faropenem (FRPM) was proved to have an excellent antimicrobial activity against penicillin-resistant Streptococcus pneumoniae. The study was planned to investigate in detail the movement of stools that had been a problem in a clinical development studies out before. In this study, an observation of the daily movement of stools was one of the principal evaluation items, hence the patients were divided into two groups. One group (S-group) were administered FRPM only, the other group (E-group) were administered FRPM in combination with a medicine for intestinal disorders (Enteronon-R). An observed frequencies of any loose bowel movements were 94.7% in S-group, and 63.2% in E-group, hence the study suggested that the combination drug was effective. The patients observed higher frequencies of development of the movement of stools, all of them were recovered from in the course of administration or within 4 days after administration, however whether or not being treated symptomatic therapy. Clinical efficacy rates of FRPM on mainly respiratory infections were 94.6%. In this study, 4 strains (patients) of penicillin-resistant Streptococcus pneumoniae were isolated. Against penicillin-resistant Streptococcus pneumoniae, FRPM demonstrated more potent antibacterial activity than the oral penicillins and cephems tested here except cefditoren. Clinical efficacies was deemed effective in all of the 4 cases, and bacteriologically, 3 organisms were eradicated. As for side effects including diarrhea and loose stool, no serious side effects were observed. Based on the above results, FRPM is effective against most infections in the pediatric field which Streptococcus pneumoniae are isolated at high frequencies highly, and is considered to cases in be useful an attention will have to be paid to stool movement, however.