[Analysis of colorants in foods using liquid chromatography-mass spectrometry].

A method using liquid chromatography coupled with mass spectrometry (LC-MS) was developed for the simultaneous determination of colorants in foods. Twenty-five colorants were extracted from foods with water or methanol and ammonia water, and cleaned up with a solid-phase extraction column. Recovery rates were between 71 and 113%, and relative standard deviations were less than 10%.

Clonality and micro-diversity of a nationwide spreading genotype of Mycobacterium tuberculosis in Japan.

Mycobacterium tuberculosis transmission routes can be estimated from genotypic analysis of clinical isolates from patients. In Japan, still a middle-incidence country of TB, a unique genotype strain designated as 'M-strain' has been isolated nationwide recently. To ascertain the history of the wide spread of the strain, 10 clinical isolates from different areas were subjected to genome-wide analysis based on deep sequencers.

Phylogenetic Clades 6 and 8 of Enterohemorrhagic Escherichia coli O157:H7 With Particular stx Subtypes are More Frequently Found in Isolates From Hemolytic Uremic Syndrome Patients Than From Asymptomatic Carriers.

Background: Enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection causes severe diseases such as bloody diarrhea and hemolytic uremic syndrome (HUS). Although EHEC O157:H7 strains have exhibited high genetic variability, their abilities to cause human diseases have not been fully examined.

Methods: Clade typing and stx subtyping of EHEC O157:H7 strains, which were isolated in Japan during 1999-2011 from 269 HUS patients and 387 asymptomatic carriers (ACs) and showed distinct pulsed-field gel electrophoresis patterns, were performed to determine relationships between specific lineages and clinical presentation.

Detection of respiratory viruses in gargle specimens of healthy children.

Background: Respiratory tract viral infection is one of the most common and important diseases in children. Polymerase chain reaction (PCR) tests are often used to detect viruses in samples, it is difficult to interpret the clinical significance of PCR positivity, which may reflect a past, imminent or active asymptomatic infection due to their high sensitivity. Although single respiratory viruses have been detected in samples from children with symptoms, other respiratory viruses can also be detected simultaneously.

Increased prevalence of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2010 to 2012.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by β-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS).

Trivalent influenza vaccine-induced antibody response to circulating influenza a (H3N2) viruses in 2010/11 and 2011/12 seasons.

To evaluate antibody response induced by trivalent inactivated influenza vaccine (TIV) against circulating influenza A (H3N2) strains in healthy adults during the 2010/11 and 2011/12 seasons, a hemagglutination-inhibition (HI) assay was utilized to calculate geometric mean antibody titer (GMT), seroprotection rate (post vaccination HI titers of ≥1 :40), and seroresponse rate (4-fold increase in antibody level). In the 2010/11 season, GMT increased 1.8- to 2.

Wide dissemination of extended-spectrum β-lactamase-producing Escherichia coli in community residents in the Indochinese peninsula.

Recent studies have reported a widespread distribution of extended-spectrum β-lactamase (ESBL)-producing bacteria, not only in the nosocomial setting, but also in the community; some local communities in Southeast Asia have been reported to show a high prevalence of ESBL-producing bacteria. However, the details regarding the quantitative/qualitative state of ESBL-producing bacterial spread in Southeast Asia are currently unclear. Thus, the aim of this study was to assess the state of ESBL-producing bacterial spread in community residents from the Indochinese peninsula, as a representative region of Southeast Asia.

Rapid and easy multiresidue method for the analysis of antibiotics in meats by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

This study involved the development of a multiresidue method for the rapid analysis of 43 antibiotics in meats using ultrahigh-performance liquid chromatography-tandem mass spectrometry. This method was performed using dispersive-solid phase extraction, which is able to analyze 20 samples within 2 h. All compounds were determined simultaneously on a C18 separation column with gradient elution.

Antibiotic residue monitoring results for pork, chicken, and beef samples in Vietnam in 2012-2013.

A monitoring plan of residual antibiotics in food of animal origin was conducted in Vietnam from 2012 to 2013. Meat samples were collected from slaughterhouses and retail stores in Ho Chi Minh City and Nha Trang. A total of 28 antibiotics were analyzed using a LC-MS/MS screening method.

Evaluation of streptococcal toxic shock-like syndrome caused by group B streptococcus in adults in Japan between 2009 and 2013.

Infection with Streptococcus agalactiae has long been recognized in infants. In recent years, S. agalactiae is an important cause of morbidity and mortality among adults and among those with underlying medical condition.

4-Methoxymethyl-2,3,5,6-tetrafluorobenzyl alcohol as a urinary biomarker for monitoring of metofluthrin, a fluorine-containing pyrethroid, in exposed rats.

Context: A fluorine-containing pyrethroid metofluthrin is widely used recently in mosquito repellents.

Objective: The urinary excretion kinetics of its metabolites was evaluated in rats to establish an optimal biomarker for monitoring metofluthrin exposure of the general population.

Methods And Results: After metofluthrin had been administered intraperitoneally to rats, the urinary excretion kinetics of the major metofluthrin metabolites was evaluated by moment analysis.

The detection of toxigenic Corynebacterium ulcerans from cats with nasal inflammation in Japan.

Corynebacterium ulcerans (toxigenic C. ulcerans) produces the diphtheria toxin, which causes pharyngeal and cutaneous diphtheria-like disease in people, and this bacterium is commonly detected in dogs and cats that are reared at home. It is considered dangerous when a carrier animal becomes the source of infection in people.

Chlamydia pneumoniae effector chlamydial outer protein N sequesters fructose bisphosphate aldolase A, providing a benefit to bacterial growth.

Background: Pathogenic chlamydiae are obligate intracellular pathogens and have adapted successfully to human cells, causing sexually transmitted diseases or pneumonia. Chlamydial outer protein N (CopN) is likely a critical effector protein secreted by the type III secretion system in chlamydiae, which manipulates host cells. However, the mechanisms of its action remain to be clarified.

Benzotriazole ultraviolet stabilizers show potent activities as human aryl hydrocarbon receptor ligands.

Benzotriazole ultraviolet stabilizers (BUVSs) used in consumer products are raising concerns as new pollutants in the aquatic environment. We determined the agonistic activities of eight BUVSs and a chemically distinct UV absorber (4-methylbenzylidinecamphor) toward the human aryl hydrocarbon receptor (AhR) and thyroid hormone receptors alpha and beta. Although none of the BUVSs showed ligand activity against the thyroid hormone receptors, four of them (UV-P, UV-9, UV-326, and UV-090) showed significant AhR ligand activity.

Impact of genotype-specific herd immunity on the circulatory dynamism of norovirus: a 10-year longitudinal study of viral acute gastroenteritis.

Human norovirus is a major cause of viral acute gastroenteritis worldwide. However, the transition of endemic norovirus genotypes remains poorly understood. The characteristics of natural immunity against norovirus are unclear because few studies have been performed in the natural infection setting.

Comparing the role of silica particle size with mineral fiber geometry in the release of superoxide from rat alveolar macrophages.

Particulate air pollutants and mineral fibers activate inflammatory cells to release oxidants, which contribute to inflammation and injury in the lower respiratory tract. Our aim was to compare the role of silica particle size with mineral fiber length and width in the ability to induce superoxide release from rat alveolar macrophages. We estimated the ability of four types of silica particle samples, with different mode diameter, and three types of mineral fiber samples, with different geometric mean lengths and widths, to induce lucigenin-dependent chemiluminescence (CL) from the cells per number of dust particles (i.

Sensitive and specific PCR systems for detection of both Chinese and Japanese severe fever with thrombocytopenia syndrome virus strains and prediction of patient survival based on viral load.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high case fatality risk and is caused by the SFTS virus (SFTSV). A retrospective study conducted after the first identification of an SFTS patient in Japan revealed that SFTS is endemic to the region, and the virus exists indigenously in Japan. Since the nucleotide sequence of Japanese SFTSV strains contains considerable differences compared with that of Chinese strains, there is an urgent need to establish a sensitive and specific method capable of detecting the Chinese and Japanese strains of SFTSV.

Development of an improved RT-LAMP assay for detection of currently circulating rubella viruses.

Rubella virus is the causative agent of rubella. The symptoms are usually mild, and characterized by a maculopapular rash and fever. However, rubella infection in pregnant women sometimes can result in the birth of infants with congenital rubella syndrome (CRS).

[Allergy due to probable contamination of bread used for school meals with milk].

Background: In May 2012, two schoolchildren developed allergic symptoms after eating a school meal of fried bread in Osaka, Japan. One specific raw material, milk, should not be present in fried bread. However, we suspected the unintentional mixing of milk in the bread manufacturing process.

Direct detection of Mycobacterium avium in environmental water and scale samples by loop-mediated isothermal amplification.

We previously demonstrated the colonization of Mycobacterium avium complex in bathrooms by the conventional culture method. In the present study, we aimed to directly detect M. avium organisms in the environment using loop-mediated isothermal amplification (LAMP), and to demonstrate the efficacy of LAMP by comparing the results with those obtained by culture.

A highly rapid and simple competitive enzyme-linked immunosorbent assay for monitoring paralytic shellfish poisoning toxins in shellfish.

Using a streptavidin-coated well plate, a biotin-labelled anti-gonyautoxin 2/3 monoclonal antibody GT-13A, and a decarbamoyl saxitoxin-peroxidase conjugate, a direct competitive enzyme-linked immunosorbent assay (PSP-ELISA) was developed for monitoring paralytic shellfish poisoning (PSP) toxins in shellfish. This assay is simple to perform and can be completed in approximately 20 min. The PSP-ELISA was compared to the mouse bioassay (MBA) for the detection of PSP toxins in shellfish samples (n=83) collected from the coast of Osaka Prefecture, Japan.

Longitudinal study on respiratory viral co-infections in the presence or absence of clinical manifestation in infants aged 0-2 years.

We conducted a long-term follow-up study between December 2005 and February 2007 on 4 immunocompetent infants, who repeatedly presented with respiratory symptoms, using PCR-based techniques targeting 14 viruses related to acute respiratory tract infection. Of 38 specimens, 30 were collected from symptomatic infants and 8 were collected when respiratory symptoms were absent. Overall, one or more respiratory viruses were detected in 94.