This study investigated the diagnostic accuracy of the quantitative polymerase chain reaction (qPCR) DNA assay in urine and saliva samples, as well as its concordance with serum cytomegalovirus (CMV) IgM/IgG testing in infants suspected of congenital cytomegalovirus (cCMV) infection. Furthermore, the study sought to elucidate the correlation between various diagnostic parameters in suspected cases of cCMV. A cross-sectional analysis was conducted on newborns suspected of having cCMV infection at Rumah Sakit Saiful Anwar (RSSA) Malang. CMV serology, complete blood count, and qPCR of urine and saliva samples were collected. Statistical analysis was performed on these data with a P-value(P) < 0.05. A significant difference in urine PCR CT value distinguished positive from negative CMV IgM serology groups. A strong correlation (r = 0.728, P < 0.001) and high agreement (κ = 0.693, P < 0.001) between urine and saliva PCR testing suggested saliva as a reliable and non-invasive alternative for newborn screening. The findings of this study underscore the necessity of a comprehensive screening protocol for cCMV, particularly considering the high seroprevalence of CMV in the Indonesian population.

Staphylococcus argenteus, a novel species formally named in 2015 and distinct from Staphylococcus aureus, has a historical distribution that remains unclear. In this study, a total of 1,021 staphylococcal isolates collected from food-related specimens in Nagoya City between 1986 and 2022 were re-examined. Of these, 65 isolates (6.4%) were re-identified as S. argenteus. The earliest detection was in 1986, and the species has been identified in almost every subsequent year. These findings suggest that S. argenteus had already disseminated into food-related environments by the 1980s. Furthermore, the results indicate that most S. argenteus isolates have been correctly identified in recent years, due to improvements in current MALDI-TOF MS identification. Multilocus sequence typing (MLST) revealed ST2854 as the most prevalent sequence type (ST) in this study, while clinically important strains, such as ST1223 and ST2250, have been detected since the 1990s. The presence of novel and multiple STs with distinct PCR-based open reading frame typing (POT) types indicates that genetically diverse S. argenteus strains have been present in food-related environments since the 1980s. These results provide important insight into the historical background of S. argenteus and underscore the need for continued monitoring, particularly in food-related environments.

Klebsiella variicola, often misidentified as Klebsiella pneumoniae, is gaining recognition as a pathogen. This study reports the first human case of infection with K. variicola harboringbla_CTX-M-14 in Japan. MALDI time-of-flight mass spectrometry was used to confirm that clinical isolates from urine and blood cultures were K. variicola. The infection was successfully treated with cefmetazole. Whole-genome sequencing identified bla_CTX-M-14 in an 8,066 bp plasmid. Given the rarity of extended-spectrum beta-lactamase-positive K. variicola infections in Japan, this case highlights the importance of accurately identifying and monitoring multidrug-resistant pathogens.

This study aimed to investigate the epidemiological and genetic characteristics of human astroviruses (HAstVs) detected during acute gastroenteritis (AG) outbreaks in Yokohama, Japan. We collected stool samples and epidemiological information between September 2017 and August 2023 and used real-time reverse transcription (RT)-PCR and/or RT-PCR to detect HAstV from 53 samples from 20 (3.1%) of the 648 virus-associated AG outbreaks during the study period. Of the 20 outbreaks investigated via sequencing, 13 were caused by classic HAstV, three by HAstV-MLB, and four were due to multiple genotypes, classic HAstV and HAstV-MLB. The strains detected in Yokohama were found to be closely related within their respective genotypes. The distribution of HAstV genotypes differed by age group, with HAstV1 and HAstV-MLB1 primarily found in 0–3-year-olds, whereas HAstV4 typically occurred in individuals over 4 years of age. Of the 53 HAstV-infected patients, 49 (92.5%) experienced diarrhea, with 36 exhibiting only this symptom. Vomiting (18.9%) was less prevalent than diarrhea. There were no differences in the symptoms between individuals with classic HAstV and HAstV-MLB.

The potency of diphtheria toxoid is determined by titrating neutralizing antibody levels in immunized mice using the Vero cell assay. The WHO manual recommends titration by determining the cytotoxic endpoint through measuring cell metabolism and observing cell morphology under a microscope, which has been performed in our laboratory; however, the former is time-consuming and the latter subjective. To address these limitations, we have developed a novel endpoint determination method based on cell image analysis. We assessed the feasibility of this image analysis and compared it with microscopic observation and cell metabolism measurement. Consequently, image analysis proved effective for endpoint determination, yielding potency values comparable to existing methods in measuring the potencies of commercial vaccines. These findings suggest that image analysis, being objective and convenient, can serve as a reliable alternative method for potency testing of diphtheria vaccines.

The present study developed a novel nano-structured nasal Bordetella pertussis vaccine candidate using filamentous haemagglutinin (FHA) and pertussis toxoid (PTd) encapsulated in N-trimethyl chitosan (TMC) with cytosine phosphoguanine (CpG) serving as both an adjuvant and crosslinker (CpG-adjuvanted TMC/PTd-FHA), followed by physicochemical characterization and immune response evaluation after nasal administration. The TMC/CpG/PTd-FHA nanoparticle (NP) exhibited a particle size and zeta potential of 289.4 nm and +25.7 mV, respectively. The antigen/toxoid-loaded NPs exhibited encapsulation efficacy exceeding 80% in polymer matrices, whereas in vitro antigen/toxoid release was found to be 95.18% after 96 hours. High immunization rates were observed in NP-treated mice with increased IgG and secretory IgA levels and strong ability to induce IFN-γ, IL-4, and IL-17 compared with the control group. Overall, nasal administration of the proposed approach, utilizing CpG as an adjuvant and crosslinker, was able to elicit humoral and Th1-type cellular immune responses, demonstrating promising potential as a vaccine delivery system.

After lifting travel bans imposed during the coronavirus 2019 pandemic, the number of reported measles cases in Japan started rising, culminating in 11 cases in Osaka Prefecture in 2024. We investigated the molecular epidemiology of these cases using 450 nucleotides of the C-terminal region of the nucleoprotein gene (N-450) and the noncoding region located between the matrix and fusion protein genes (MF-NCR). N-450 analysis revealed eight cases of genotype D8 and three of B3. Seven of the D8 cases were closely related to strains from Central Asia and Europe, harboring mutations in the primer binding region targeted by real-time PCR assays for the measles virus. The remaining D8 case matched a strain from Thailand. All three B3 cases were identical to the strain detected in Vietnam in 2024. MF-NCR analysis of D8 cases revealed similar trends to those observed in the N-450 analysis. However, the B3 viruses from Vietnam differed by several bases from the closest related sequence and included a six-base insertion. Given the resurgence of measles in Vietnam since 2024, the potential risk of continuous measles importation remains. Attention should be focused on measles surveillance under circumstances of increased international human interactions, specifically the Expo 2025 Osaka, Kansai, Japan.

An ongoing pertussis epidemic in Okinawa has resulted in 227 reported cases since November 2024. Between December 2024 and February 2025, clinical specimens were collected from 31 cases. We isolated 18 macrolide-resistant Bordetella pertussis (MRBP) strains, all harboring the A2047G mutation in the 23S rRNA gene, confirmed by real-time PCR. Genomic analysis was performed on 2 MRBP strains isolated in November 2024 and the 18 MRBP strains from the current survey. All MRBP strains in Okinawa formed genetically related clusters with the ptxP3 allele in China (P745) and France (FR7302). However, MRBP strains from Okinawa were divided into three clusters, each separated by at least eight SNPs, and distinct from P745 and FR7302, suggesting the multi-source dissemination of ptxP3 MRBP in Okinawa.