Virucidal efficacy of hypochlorous acid water for aqueous phase and atomization against SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is an infectious viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged at the end of 2019. SARS-CoV-2 can be transmitted through droplets, aerosols, and fomites. Disinfectants such as alcohol, quaternary ammonium salts, and chlorine-releasing agents, including hypochlorous acid, are used to prevent the spread of SARS-CoV-2 infection. In the present study, we investigated the efficacy of ionless hypochlorous acid water (HOCl) in suspension and by spraying to inactivate SARS-CoV-2. The virucidal efficacy of HOCl solution in tests against SARS-CoV-2 was evaluated as 50% tissue culture infectious dose. Although the presence of organic compounds influenced the virucidal efficacy, HOCl treatment for 20 s was significantly effective to inactivate Wuhan and Delta strains in the suspension test. HOCl atomization for several hours significantly reduced the SARS-CoV-2 attached to plastic plates. These results indicate that HOCl solution with elimination containing NaCl and other ions may have high virucidal efficacy against SARS-CoV-2. This study provides important information about the virucidal efficacy and use of HOCl solution.

Microbiological analysis concerning the antibacterial effect of atomized Ionless® hypochlorous acid water in a nursery school environment.

INTRODUCTION: In daycare centers, infants come in close contact with each other, and contact, droplet, and mouth-to-mouth infections may occur owing to sharing of toys. Additional effective disinfection methods should be considered aside from wiping with disinfectants-including alcohol or sodium hypochlorite solution-for environmental disinfection of daycare centers. We aimed to examine the usefulness of hypochlorous acid water atomization in the effective disinfection of the classroom environment and toys at a nursery school. METHODS: Environmental cultures of the nursery and toys were prepared to evaluate the species and bacterial load and to assess the contaminated areas. Staphylococcus aureus petri dishes were placed at high-frequency contact sites, and hypochlorous acid water was atomized to achieve a 0.03-ppm atmospheric chlorine concentration. After the atomization, the amount of S. aureus bacteria on the Petri dish and the changes in bacterial count isolated from the environment and toys were evaluated. RESULTS: Hypochlorous acid water atomization was performed for 5 h to avoid condensation. After a 3-h atomization, ≥99.99% of S. aureus was eliminated on petri dishes; furthermore, a significant disinfection effect was observed on environmental bacteria at least 1 h after atomization. For rubber and textile toys, the significant disinfection effect was observed 1 h after atomization, and for plastic toys, the effect was observed 3 h after atomization. CONCLUSIONS: Hypochlorous acid water atomization is a useful strategy to disinfect nursery school classrooms.

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%.

Clinical Manifestation of Patients With Atypical Hemolytic Uremic Syndrome With the C3 p.I1157T Variation in the Kinki Region of Japan.

The gain-of-function variation p.I1157T in C3 was previously identified in 8 patients with atypical hemolytic uremic syndrome (aHUS) at Mie University Hospital. In the present study, we identified another 11 patients with aHUS with this variation, including 10 pediatric patients (onset age: 1-16 years). The variation seems to be geographically concentrated around Mie Prefecture in Japan. Fifteen of the 19 patients with aHUS experienced infection as probable triggering events. All 19 patients had renal dysfunction. Seven patients, including 2 from the previous study and 5 from the present study, were treated with eculizumab, with all showing a good response with hematological normalization. Among the 5 eculizumab-treated patients in the present study, 3 had an ambiguous diagnosis of aHUS due to low-grade hemolysis even with elevated levels of lactate dehydrogenase and bilirubin. In those cases, in-house targeted DNA sequencing identified the C3 p.I1157T variation carriers, which enabled the early initiation of treatment with eculizumab. The present study supports the early introduction of eculizumab in patients with aHUS, especially pediatric patients.

Immunogenicity and safety of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with DTPa vaccine in Japanese children: A randomized, controlled study.

This phase III, randomized, open-label, multicenter study (NCT01027845) conducted in Japan assessed the immunogenicity, safety, and reactogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV, given intramuscularly) co-administered with diphtheria-tetanus-acellular pertussis vaccine (DTPa, given subcutaneously). Infants (N=360 ) were randomized (2:1) to receive either PHiD-CV and DTPa (PHiD-CV group) or DTPa alone (control group) as 3-dose primary vaccination (3-4-5 months of age) and booster vaccination (17-19 months of age). Immune responses were measured before and one month after primary/booster vaccination and adverse events (AEs) were recorded. Post-primary immune responses were non-inferior to those in pivotal/efficacy European or Latin American pneumococcal protein D-conjugate vaccine studies. For each PHiD-CV serotype, at least 92.6% of infants post-primary vaccination and at least 97.7% of children post-booster had pneumococcal antibody concentrations ≥0.2 µg/ml, and at least 95.4% post-primary and at least 98.1% post-booster had opsonophagocytic activity (OPA) titers ≥8 . Geometric mean antibody concentrations and OPA titers (except OPA titer for 6B) were higher post-booster than post-priming for each serotype. All PHiD-CV-vaccinated children had anti-protein D antibody concentrations ≥100 EL.U/ml one month post-primary/booster vaccination and all were seroprotected/seropositive against each DTPa antigen. Redness and irritability were the most common solicited AEs in both groups. Incidences of unsolicited AEs were comparable between groups. Serious AEs were reported for 47 children (28 in PHiD-CV group); none were assessed as vaccine-related. In conclusion, PHiD-CV induced robust immune responses and was well tolerated when co-administered with DTPa in a 3-dose priming plus booster regimen to Japanese children.

A practical approach estimating etiologic agents using real-time PCR in pediatric inpatients with community-acquired pneumonia.

To evaluate pathogens in pediatric inpatients with community-acquired pneumonia (CAP), an Acute Respiratory Diseases Study Group organized by ten Japanese medical institutions devised a rapid, reliable process based on real-time PCR results in nasopharyngeal swab samples plus admission blood test results. From April 2008 to April 2009, we enrolled 903 children with CAP based on chest radiographs and clinical findings who were hospitalized within 5 days of onset. Comprehensive real-time PCR was used to detect 6 bacteria and 11 respiratory viruses. The swab specimens also were used for bacterial cultures. After initial determination of presence or absence of viral and mycoplasmal infections, significant bacterial contributions were defined by bacterial identification, clinical efficacy of antimicrobial agent, and reference to blood test results. Children were stratified by age: below 1 year, 1 year, 2-5 years, or at least 6 years old. Among patients studied, 34.4 % were diagnosed with viral infection; 21.8 %, bacterial infection; 17.5 %, viral/bacterial co-infection; 5.9 %, mycoplasmal infection; 0.3 %, mycoplasmal/bacterial co-infection; and 1.7 %, viral/mycoplasmal co-infection. The remaining 18.4 % had unknown pathogens. Purely viral infection was suggested mainly in infants younger than 1 year; mycoplasmal infection typically occurred in children at least 6 years old. Our results suggest usefulness of real-time PCR for nasopharyngeal samples together with blood tests in estimating etiologic agents in clinical settings.

[Rotavirus vaccine].

Rotavirus is the single main cause of severe acute gastroenteritis in children less than 5 years of age, resulting in over 527,000 deaths worldwide annually. The majority of rotavirus-related deaths are seen in less-developed countries; in developed countries, rotavirus is an infrequent cause of death but a commom cause of hospitalizations. Rotavirus gastroenteritis was also estimated to result in approximately 790,000 doctor visits every year leading to medical intervention among children aged 0-5 years in Japan. At present, the treatment of rotavirus gastroenteritis in Japan is limited to symptomatic measures and no antiviral therapy is available. A phase III, randomized, double-blind study evaluated the efficacy, reactogenicity, safety and immunogenicity of a human rotavirus vaccine in Japanese infants. Rotavirus vaccine was efficacious, well-tolerated and immunogenic in Japanese infants and introduction of vaccination would help in reducing the disease burden.

Efficacy, safety and immunogenicity of RIX4414 in Japanese infants during the first two years of life.

A phase III, randomized, double-blind study evaluated the efficacy, reactogenicity, safety and immunogenicity of a human rotavirus vaccine, RIX4414 in Japanese infants aged 6-14 weeks when administered as two doses (0, 1-month schedule). Efficacy against any and severe rotavirus gastroenteritis leading to medical intervention caused by circulating wild-type rotavirus from two weeks post-Dose 2 until two years of age was 79.3% (95% CI: 60.5-89.8%) and 91.6% (95% CI: 62.4-99.1%), respectively. Solicited, unsolicited symptoms and serious adverse events were reported at a similar frequency in both groups. Serum anti-rotavirus antibody seroconversion rate one-month post-Dose 2 was 85.3% (95% CI: 68.9-95%) in RIXX4414 group. RIX4414 was efficacious, well-tolerated and immunogenic in Japanese infants and introduction of vaccination could help in reducing the disease burden.

Effect of angiotensin-converting enzyme inhibitor on matrix metalloproteinase-9 activity in patients with Kawasaki disease.

BACKGROUND: Matrix metalloproteinase (MMP)-9 is thought to be involved in coronary artery aneurysms (CAAs) in patients with Kawasaki disease (KD); however, MMP-9 inhibitors are not used clinically. This study investigated whether the angiotensin-converting enzyme (ACE) inhibitor captopril could inhibit serum MMP-9 activity using serum from KD patients in an in vitro experiment. METHODS: In 7 KD patients, serum MMP-9 activity was measured using the MMP-9 assay kit 3 times: before and after intravenous immunoglobulin (IVIG) treatment, and during the convalescent phase. The effect of captopril on MMP-9 activity was also assessed using serum obtained before IVIG treatment. RESULTS: Serum MMP-9 activity was significantly higher during the pre-treatment phase than during the post-treatment and convalescent phases. MMP-9 activity during the pre-treatment phase was dose-dependently inhibited by captopril, and the IC(50) for MMP-9 was 500nM. The potency of captopril for MMP-9 inhibition was comparable to that for ACE inhibition. CONCLUSION: ACE inhibitor may be effective for preventing CAA formation in KD patients, especially IVIG non-responders.

Rapid culture-free identification and molecular typing of Shiga toxin-producing Escherichia coli by PCR-RFLP.

Using culture-independent technology, PCR-RFLP were used to identify and type STEC in the stool of a patient with HUS. Fecal PCR-RFLP patterns were identical to those of the STEC O157:H7 isolated from the patient.

Anorexia nervosa and refeeding syndrome. A case report.

This is a case story of a 14-year-old girl with severe anorexia nervosa (AN) (158 cm, 28 kg, -44.1% ideal body mass index), admitted with purpura, edema, and general fatigue. We treated her carefully and paid particular attention to prevent development of refeeding syndrome (RS), and her body weight increased satisfactorily. However, RS (edema, hypoalbuminemia, and heart failure) occurred despite careful treatment. We used albumin and diuretics for treatment of RS, but severe liver damage resulted. RS was aggravated by the medical treatment. More attention should have been paid to her weight gain and medical treatment should have been initiated more slowly to prevent dramatic changes in the patient's fluid and electrolyte status.

Assessment of real-time PCR for diagnosis of Mycoplasma pneumoniae pneumonia in pediatric patients.

We developed a real-time PCR to detect Mycoplasma pneumoniae with a primer set designed for the 16S rRNA gene. Clinical samples (n=937) were collected from children with community-acquired pneumonia between April 2002 and March 2004 at 12 Japanese medical institutions. Sensitivity of real-time PCR was calculated as 10 colony-forming units per reaction tube using a pMP01 plasmid carrying a 225-bp target DNA fragment of the 16S rRNA gene in M. pneumoniae M129, a standard strain. Results, obtained within 2 h, were compared with those of conventional culture and serologic methods. Of all cases tested, 151 (16.4%) and 129 (13.8%) were positive for M. pneumoniae by real-time PCR and by culture, respectively. Among the 151 cases, almost all of those tested serologically by passive agglutination showed a rise in M. pneumoniae antibody titre between acute and convalescent sera. We conclude that this real-time PCR can identify M. pneumoniae rapidly and fulfills the need for rapid identification, high sensitivity, and high specificity.

Emergence of macrolide-resistant Mycoplasma pneumoniae with a 23S rRNA gene mutation.

A total of 195 Mycoplasma pneumoniae strains were isolated from 2,462 clinical specimens collected between April 2002 and March 2004 from pediatric outpatients with respiratory tract infections. Susceptibilities to six macrolide antibiotics (ML), telithromycin, minocycline, levofloxacin, and sitafloxacin were determined by the microdilution method using PPLO broth. A total of 183 M. pneumoniae isolates were susceptible to all agents and had excellent MIC90s in the following order: 0.00195 microg/ml for azithromycin and telithromycin, 0.0078 microg/ml for clarithromycin, 0.0156 microg/ml for erythromycin, 0.0625 microg/ml for sitafloxacin, 0.5 microg/ml for minocycline, and 1 microg/ml for levofloxacin. Notably, 12 ML-resistant M. pneumoniae strains were isolated from patients with pneumonia (10 strains) or acute bronchitis (2 strains). These strains showed resistance to ML with MICs of >or=1 microg/ml, except to rokitamycin. Transition mutations of A2063G or A2064G, which correspond to A2058 and A2059 in Escherichia coli, in domain V on the 23S rRNA gene in 11 ML-resistant strains were identified. By pulsed-field gel electrophoresis typing, these strains were classified into groups I and IIb [corrected] as described previously (A. Cousin-Allery, A. Charron, B. D. Barbeyrac, G. Fremy, J. S. Jensen, H. Renaudin, and C. Bebear, Epidemiol. Infect. 124:103-111, 2000). These findings suggest that excessive usage of MLs acts as a trigger to select mutations on the corresponding 23S rRNA gene with the resultant occurrence of ML-resistant M. pneumoniae. Monitoring ML susceptibilities for M. pneumoniae is necessary in the future.

Swelling behavior of poly(sodium acrylate) gels crosslinked by aluminum ions.

The cylindrical poly(sodium acrylate) gel (SA gel) was synthesized in the glass capillary using aluminum ions as the crosslinker. The swelling ratio of the gel was measured after the repeated exchange of solvent (distilled deionized water, about pH 5.8). The gel exhibited two relaxation processes; at first the gel swells rapidly as exchange of water (the swelling process), then shrinks very slowly (the shrinking process). In order to reveal the microscopic structural change (especially, the formation of hydrogen bonding) by water exchange, attenuated total refraction (ATR) Fourier transform infrared (FT-IR) spectroscopy was applied to the gels with different swelling ratio. The IR absorption peaks of the gel were assigned based on those of poly(sodium acrylate) aqueous solutions at different pH. On the swelling process, the carboxyl groups were gradually protonated, and the intermolecular hydrogen bonding started to form in the gel with maximum swelling ratio. On the shrinking process, the formation of hydrogen bonding gradually increased with long-time repeated water exchange which resulted in the shrinkage of the gel. Effects of the repeated water exchange on the swelling behavior were discussed in terms of the exchange of counter ions and the formation of hydrogen bonding.

Pharmacokinetics of low-dose all-trans retinoic acid in Japanese children with cancer.

All-trans retinoic acid (ATRA) is used as differentiation therapy for acute promyelocytic leukemia (APL). The two major adverse effects of ATRA therapy are hyperleukocytosis and retinoic acid syndrome. In order to prevent these adverse effects, low-dose ATRA therapy (25 mg/m2/d) has been tried in adults. Accordingly we assessed the pharmacokinetics of low-dose ATRA in children with cancer. Four children (one with APL and three with other advanced cancer) were administered ATRA and its pharmacokinetics were evaluated. In three patients, the pharmacokinetic parameters of ATRA were similar to those previously determined for APL patients in remission, but the values were lower in one patient. Low-dose ATRA was effective for APL, but not for the solid tumors. This therapy did not cause any severe toxicity. Further studies are needed to determine the optimum ATRA regimen and to evaluate low-dose ATRA combined with chemotherapy in children with APL.

Application of PCR for Mycoplasma pneumoniae detection in children with community-acquired pneumonia.

Between April 2002 and March 2003, to detect Mycoplasma pneumoniae by polymerase chain reaction (PCR), a primer set designed for the 16S rRNA gene was used to examine clinical samples from 369 children with community-acquired pneumonia. Samples were collected from 12 Japanese institutions participating in a study group concerning acute respiratory infectious diseases. The sensitivity of primers--2 CFU per reaction tube, using M. pneumoniae M129, a standard strain--was calculated to represent 1.1 x 10(3) M. pneumoniae organisms adherent to the tip of the swab used to collect clinical samples. Results for PCR were obtained within 2.6 h. Cases identified by PCR, cultures, and serologic tests were 68 (18.4%), 53 (14.4%), and 76 (20.6%) respectively. Among 57 PCR-positive patients tested serologically, 56 showed a significant elevation or rise in antibody titer. PCR positivity was high among patients prescribed beta-lactam antibiotics (86.7%) or no antibiotic (87.0%) before PCR analysis, but was low among patients receiving macrolides, new quinolones, or tetracyclines (37.5%). We concluded that the PCR constructed by us had a high probability for confirming a diagnosis of M. pneumoniae pneumonia and for guiding antibiotic choice for patients not yet treated.

Alpha-tocopherol content and alpha-tocopherol transfer protein expression in leukocytes of children with acute leukemia.

Alpha-tocopherol (a form of vitamin E) is a fat-soluble vitamin that can prevent lipid peroxidation of cell membranes. This antioxidant activity of alpha-tocopherol can help to prevent cardiovascular disease, atherosclerosis and cancer. We investigated the alpha-tocopherol level and the expression of alpha-tocopherol transfer protein (alpha-TTP) in the leukocytes of children with leukemia. The plasma and erythrocyte alpha-tocopherol levels did not differ between children with leukemia and the control group. However, lymphocytes from children with leukemia had significantly lower alpha-tocopherol levels than lymphocytes from the controls (58.4 +/- 39.0 ng/mg protein versus 188.9 +/- 133.6, respectively; p < 0.05), despite the higher plasma alpha-tocopherol/cholesterol ratio in the leukemia group (5.83 +/- 1.64 micromol/mmol versus 4.34 +/- 0.96, respectively; p < 0.05). No significant differences in the plasma and leukocyte levels of isoprostanes (the oxidative metabolites of arachidonic acid) were seen between the leukemia patients and controls. The plasma level of acrolein, a marker of oxidative stress, was also similar in the two groups. Investigation of alpha-TTP expression by leukocytes using real-time PCR showed no difference between the two groups. These findings suggest that there may be comparable levels of lipid peroxidation in children with untreated leukemia and controls, despite the reduced alpha-tocopherol level in leukemic leukocytes.

Neopterin, biopterin, and nitric oxide concentrations in the cerebrospinal fluid of children with central nervous system infections.

We measured neopterin, biopterin and nitric oxide (NO) concentrations in the cerebrospinal fluid of pediatric patients with central nervous system (CNS) infectious diseases. The nitric oxide and neopterin concentrations were significantly elevated in encephalitis patients, especially in two cases with serious neurological sequelae, while the biopterin levels were not elevated. The bacterial meningitis patients, on the contrary, had high cerebrospinal fluid concentrations of neopterin and biopterin, but not of NO. Although these findings are preliminary, it may suggest that cerebrospinal fluids nitric oxide would be a useful marker to prospect neurological prognoses in the CNS infections.

a-Tocopherol Content and a-Tocopherol Transfer Protein Expression in Leukocytes of Children with Acute Leukemia.

α-Tocopherol (a form of vitamin E) is a fat-soluble vitamin that can prevent lipid peroxidation of cell membranes. This antioxidant activity of α-tocopherol can help to prevent cardiovascular disease, atherosclerosis and cancer. We investigated the α-tocopherol level and the expression of α-tocopherol transfer protein (α-TTP) in the leukocytes of children with leukemia. The plasma and erythrocyte α-tocopherol levels did not differ between children with leukemia and the control group. However, lymphocytes from children with leukemia had significantly lower α-tocopherol levels than lymphocytes from the controls (58.4±39.0 ng/mg protein versus 188.9±133.6, respectively; p<0.05), despite the higher plasma α-tocopherol/cholesterol ratio in the leukemia group (5.83±1.64 µmol/mmol versus 4.34±0.96, respectively; p<0.05). No significant differences in the plasma and leukocyte levels of isoprostanes (the oxidative metabolites of arachidonic acid) were seen between the leukemia patients and controls. The plasma level of acrolein, a marker of oxidative stress, was also similar in the two groups. Investigation of α-TTP expression by leukocytes using real-time PCR showed no difference between the two groups. These findings suggest that there may be comparable levels of lipid peroxidation in children with untreated leukemia and controls, despite the reduced α-tocopherol level in leukemic leukocytes.