An advanced and fully automated chemiluminescent enzyme immunoassay for the hepatitis C virus core antigen (HCVcAg) was recently developed in Japan. We aimed to evaluate its clinical utility. The new Fujirebio assay (Lumipulse Presto HCVcAg [LP-Presto]) was compared with 2 conventional assays (Lumipulse Ortho HCVcAg [LP-Ortho] and Abbott’s Architect HCVcAg). Basic assessments of LP-Presto (reproducibility, stability, range of quantitation, and specificity) were performed on 220 frozen sera (83 positive and 137 negative by LP-Ortho) and 206 fresh sera (all negative by LP-Ortho). Correlation analysis was performed and the rates of concordance for each assay were determined. Additionally, the frozen sera of 42 hyperimmunoglobulinemia patients, including 3 unmeasurable by LP-Ortho, were tested by LP-Presto. All the basic assessments of LP-Presto were consistent with the results of LP-Ortho and Architect. The concordance rate between LP-Presto and LP-Ortho for the 220 frozen sera was 99.5% (219/220), and that between LP-Presto and Architect was 99.1% (218/220). LP-Presto (HCVcAg cut-off value; 20 fmol/L) was fully consistent with LP-Ortho (100%), which found 343 sera negative for HCVcAg. All 42 hyperimmunoglobulinemic sera were measurable using LP-Presto. In conclusion, the performance of LP-Presto was rapid and reliable, and nonspecific test results due to hyperimmunoglobulinemia were reduced when LP-Presto was used. Therefore, LP-Presto is a high-quality HCVcAg assay that shows promising applications.

The number of food consumers (eaters) and patients per outbreak followed a log-normal distribution in food poisoning caused by microbes. In contrast, it followed a scale-free distribution in food poisoning caused by plant or animal toxins. Attack rates of the individual outbreaks were distributed continuously and almost linearly from ＞ 0 to 1 for all the food poisoning cases, i.e., they could not be represented by median and standard deviation. For simultaneous monitoring of the number of patients and the attack rate in individual outbreaks, the number of patients was plotted on the x-axis in the logarithmic scale against the attack rate on the y-axis in the normal scale. This led to the formation of plots characterized by repeating arcs, assuming the shape of a butterfly with extended wings when viewed from above, which was called “backbone configuration.” The butterfly-shaped plot patterns were generally stable over time, although it varied depending on the pathogens, implicated facilities and their combinations. The backbone configuration was reproduced assuming that the number of patients per outbreak was distributed continuously from 1 to the number of eaters per outbreak.

Human papillomavirus (HPV)-associated disease is common among men with HPV infection. A quadrivalent HPV (qHPV) vaccine has demonstrated 85.9% efficacy against HPV6/11/16/18-related, persistent (≥ 6 month) infection in a study of Japanese men aged 16–26 years old. Here, we report the results of an open-label study of the immunogenicity and tolerability of the qHPV vaccine (NCT02576054), conducted to bridge findings from Japanese men to Japanese boys aged 9–15 years old. A total of 100 boys completed a three-vaccination regimen (Day 1, and Months 2 and 6), and 99 boys were included in the primary analysis population. The rate of seroconversion at one month after vaccine Dose 3 (Month 7) was high for each type of HPV (anti-HPV6/11/16/18 seroconversion rates [95% CI]: 94.9% [85.5%, 98.3%], 99.0% [94.4%, 100.0%], 99.0% [94.5%, 100.0%], and 99.0% [94.4%, 100.0%], respectively). Moreover, anti-HPV6/11/16/18 geometric mean titers were 482.9 mMU/mL, 1052.8 mMU/mL, 3878.3 mMU/mL, and 1114.5 mMU/mL, respectively. Immune responses to the qHPV vaccine were non-inferior among Japanese boys included in the current study and compared with young Japanese men from a separate study. Injection-site reactions were the most common adverse events, and administration of the vaccine was well tolerated in Japanese boys.

The spread of Panton-Valentine leucocidin (PVL)-carrying S. aureus strains in patients with wound infections in both the community and hospitals is increasing in some areas of Iran. In the present study, we determined the molecular characteristics and distribution of PVL-producing S. aureus strains isolated from wound infections. Genes encoding resistance, toxins, and staphylococcal enterotoxins were analyzed by polymerase chain reaction assays. Genotyping was performed using multi-locus sequence typing. Aminoglycoside resistance genes including ant (4′)-Ia (57.4%) and aac (6′)-Ie/aph (2″) (45.7%) were the most prevalent genes in isolates. Staphylococcal enterotoxin type A, as the most frequent type, was present in 20.2% of isolates. Strains belonged to seven clonal complexes. The most frequent clonal complex was CC30 (ST30) (29.8%), followed by CC22 (ST22) (21.3%), CC8 (ST8 and ST931) (17%), CC88 (ST88) (10.6%), CC59 (ST59 and ST338) (8.5%), CC1 (ST772 and ST1) (7.5%), and CC15 (ST15) (5.3%). Our findings indicated an increasing trend of CC30, carrying a wide range of resistance and toxin genes, which could present an obstacle in the treatment of patients with wound infections. Further studies are required to investigate the carriage of resistance, the antibiotic susceptibility pattern, and toxins encoding genes in different molecular types.

Dozens of broadly neutralizing antibodies (bnAbs) have been identified from chronically infected HIV-1 patients, but it is still unclear what determines the acquisition of broad neutralizing activities. Two chronic HIV-1 infected cases with similar autologous neutralizing activities were followed up for two years to study the viral evolution of the envelope gene and the neutralizing activity against autologous and heterologous viruses. The neutralization activities against homologous viruses gradually increased in both patients. HA172 eventually developed a cross-clade neutralizing antibodies response, with a neutralization breadth of 88.9% (8/9) against tier 2 heterologous HIV-1. However, HA084 could only neutralize 44.4% (4/9) of the same virus panel. Higher genetic diversity of the env gene at baseline (0.027 vs. 0.002, p ＜ 0.001), stronger immune pressure on V3 (3.08 vs. 0.99, p ＜ 0.001) or V4 loops (2.63 vs. 0.62, p = 0.002), increasing length of V1V2 and V4 loops, and evolution on V1V2 and CD4-binding sites (CD4bs) were identified in HA172. The findings demonstrated that higher viral genetic diversity, viral evolution on V1V2 and CD4bs might contribute to the development of bnAbs. The findings indicate the possibility of inducing better neutralizing antibodies in immunodeficient patients and may help develop an immune therapy strategy based on bnAbs.

Respiratory viral and atypical bacterial agents lead to infections in a large spectrum, from mild symptoms to respiratory failure. In the present study, we aimed to detect multiple viral and bacterial agents in the respiratory samples of inpatients by real-time polymerase chain reaction (RT-PCR). Nasopharyngeal swabs and broncho-alveolar lavage samples from inpatients with respiratory infection symptoms at the Uludag University Hospital between December 1, 2015 and March 31,2018 were investigated. DNA/RNA was extracted using the EZ1 Virus Mini Kit v2.0 (Qiagen, Belgium) with the EZ1 extraction device (Qiagen, Belgium). The R-GENE^® RT-PCR (Biomerioux, France) kit was used to detect influenza A, influenza B, respiratory syncytial virus (RSV), human metapneumovirus, rhinovirus/enterovirus (RV/EV), adenovirus, human bocavirus (hBoV), corona virus, parainfluenza virus, Chlamydia pneumoniae/Mycoplasma pneumoniae, and Legionella pneumophila in Rotor-Gene Q (Qiagen, Belgium). Patients were aged between 0 and 90 years. Overall, 177 (56.9%) patients were men and 134 (43.1%) were women. A total of 311 samples were analyzed, of which 214 (68.8%) were positive. In total, 360 agents, including 338 viruses and 22 bacteria, were detected. The commonest agents were influenza A+B (n = 65, 18,1%), hBoV (n = 64, 17.8%), RV/EV (n = 56, 15.6%), and RSV (n = 47, 13.1%). Rapid diagnosis of viral infections by RT-PCR is important for the specific treatment of patients.

Lactobacillus rhamnosus is a gram-positive, rod-shaped bacterium and is commonly used as a probiotic to maintain intestinal health. Recently, surveillance of Lactobacillus bacteremia was conducted using a biochemical test and conventional PCR assay; however, these assays are unable to quantify the target and might yield a false positive result. In this study, we developed an L. rhamnosus-specific quantitative PCR assay, which yields accurate and reproducible results on the basis of the specificity of a TaqMan probe targeting the unique 16S rDNA sequence of L. rhamnosus. The assay specifically detected the target bacterium, L. rhamnosus, and no nonspecific signals were generated under the assay conditions. With genomic DNA from the cells of L. rhamnosus (10¹ to 10⁶ cells), the threshold cycle values showed a linear dependence (R² = 0.9993). This L. rhamnosus-specific quantitative PCR assay can advance the research into the effects of this microorganism on microflora, microbial infections, and on the host.

The National Action Plan on Antimicrobial Resistance in Japan aims to achieve a 50% reduction in the use of broad-spectrum oral antimicrobials (cephalosporins, macrolides, and quinolones) from 2013 to 2020. Based on the national sales data for antimicrobials, we estimated the regional antimicrobial use (AMU) from 2013–2016 and evaluated the differences in the use of broad-spectrum oral antimicrobials among three regions in which differences had been identified previously. The AMU was standardized based on the defined daily dose (DDD) and described as the DDDs/1,000 inhabitants/day (DID). Annual combined total oral and parenteral AMU during 2013–2016 was 14.9, 14.5, 14.7, and 14.6 DID, respectively. The change in mean ± standard deviation in the total AMU at the prefectural level was – 0.2 ± 0.8 DID. Among the 47 prefectures, decreasing trends were observed in 34, while in the remaining 13 prefectures increasing trends were recorded. In 2016, no significant differences in the mean usage of oral cephalosporins among the three regions were observed. The mean usage of oral macrolides in the eastern (4.1 DID) was significantly lower than that in the central region (4.7 DID) (p = 0.009) and the western (4.8 DID) (p = 0.002). The mean usage of oral quinolones in the western (3.2 DID) was significantly higher than that in the eastern (2.3 DID) (p ＜ 0.001) and central (2.7 DID) (p = 0.001) regions. To determine appropriate targets for the implementation of antimicrobial stewardship for reducting the use of broad-spectrum oral antimicrobials, further studies are required to identify the reasons underlying these differences.

Histoplasmosis is occasionally encountered in non-endemic countries owing to more frequent international travel and migration, as well as an increase in the number of vulnerable hosts (e.g., patients with cellular immunodeficiencies). However, the diagnosis of endemic mycoses may be challenging because of its rarity and the limited availability of diagnostic tests. We report a case of disseminated histoplasmosis in a human immunodeficiency virus (HIV)-infected Japanese man who had often travelled to histoplasmosis-endemic countries. We also reviewed the reported cases of HIV-associated histoplasmosis in Japan. To the best of our knowledge, this is the ninth case report of co-infection with Histoplasma and HIV in Japan and the second involving a Japanese patient. This case emphasizes the importance of noting the details of not only the present residence of patients, but also their previous residence and travels. If histoplasmosis is suspected, physicians should inform laboratory personnel that fungal cultures should be incubated for 6 weeks, and compliance with biosafety guidelines for handling the specimens should be practiced. Since death occurs in nearly 50% of HIV-associated histoplasmosis cases in Japan, early recognition, timely diagnosis, and appropriate treatment are mandatory.

The second largest epidemic of hand, foot, and mouth disease since 1982 occurred in 2017, which involved 6,173 cases in Osaka City, Japan. The main causative agent was coxsackievirus A6 (CV-A6). Phylogenetic analysis revealed that the detected CV-A6 strains belonged to genetic groups A3 and A4 in clade A.

Subclinical mastitis (SCM) is regarded as both a problem for dairy producers and a threat to human health worldwide owing to the potential bacterial contamination of milk and dairy products, particularly those made from raw milk. In the present study, we isolated Escherichia coli from 14 (9.3%) SCM milk samples. We serotyped each E. coli isolate (n = 14), and investigated its potential pathogenicity and antimicrobial resistance (AMR). The serotyping results showed that the E. coli isolates belonged to serotypes O55:H7 (n = 2), O111:H4 (n = 2), O127:H6 (n = 2), O128:HUT (n = 2), O26:HUT (n = 1), O44:H18 (n = 1), O114:H21 (n = 1), O86:HUT (n = 1), O124:HUT (n = 1), and O127:H7 (n = 1). Potential pathogenicity was detected in 93% (13/14) of the isolates. In particular, 13 isolates possessed at least one of the examined virulence genes. Ten isolates (71%) exhibited AMR to at least one of the tested antimicrobials, four (40%) were multidrug-resistant, and one isolate produced extended-spectrum β-lactamases. The obtained results indicate that SCM acts as a source for the spread of potentially pathogenic E. coli strains that are resistant to many groups of antimicrobials, and may constitute a hazard to both public and animal health.

In July 2018, a Japanese traveler returning from Saudi Arabia was diagnosed with dengue. The dengue virus type 2 gene was detected from a whole blood sample. Phylogenetic analysis revealed that the strain was clustered with isolates from Singapore and India. Travelers to Saudi Arabia should be cautious about mosquito bites.

We performed Leptospira culture analysis of 76 clinical samples collected from animals and of six soil samples for the investigation of a leptospirosis outbreak in southern Thailand in 2017. Leptospires were recovered from a kidney sample (a fatal canine leptospirosis case) and from all the soil samples. Next, 16S rRNA sequence analysis demonstrated that the clinical isolate was closely related to the pathogenic L. interrogans, whereas the soil isolates represented different species, including pathogenic L. ellisii, intermediate L. wolffii, and nonpathogenic L. yanagawae. Multilocus sequence typing identified an isolate of L. interrogans as a novel sequence type (ST263), suggesting that the causative agent of the canine leptospirosis in the southern Thailand outbreak has a unique genetic profile.

An 84-year-old man with chronic renal failure, anemia, and diabetes was admitted for hemodialysis initiation. His vital signs were stable until the eighteenth hospital day, before acquiring an influenza A virus infection. Three days later, he died of septic shock with severe liver impairment. His leukocyte count, prothrombin time (PT-INR), and liver enzyme levels such as aspartate transaminase and alanine aminotransferase, were significantly increased. Hypercytokinemia was also observed. Autopsy revealed bilateral diffuse pneumonia with neutrophil infiltration. The liver showed extensive centrilobular hepatocyte necrosis. Immunohistochemistry for influenza A nucleoprotein revealed positivity in the ciliated columnar epithelium of the bronchi and negativity in the trachea, lungs, and liver. Hypoxic hepatitis is characterized by an abrupt and massive increase in aminotransferase levels (＞ 20 times upper normal limit) due to anoxic centrilobular hepatocyte necrosis. The occurrence of hypoxic hepatitis requires a pre-existing, chronic condition, such as anemia, causing reduced oxygen supply to the liver, followed by an acute decrease in hepatic oxygen supply, such as septic shock. Therefore, this report suggests that hypoxic hepatitis can be an important causative factor for acute liver failure associated with influenza virus infection.

Human metapneumovirus (HMPV) has been a major causative agent of acute respiratory infections in humans. Recently, two types of variant A2b subtype HMPV strains possessing a 111- or 180-nucleotide duplication (nt-dup) in the G gene (HMPV A2b_180nt-dup and HMPV A2b_111nt-dup, respectively) were detected in Japan, Spain, Vietnam, and China. Our surveillance for infectious agents in Yokohama City, Japan revealed that the HMPV A2b_111nt-dup strain became predominant in Yokohama City in 2018. In contrast, no classic HMPV A2b strain was detected after 2017. These data indicate a beneficial role of the 111nt-dup in the G gene for the transmission of HMPV.