Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization.

Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.

Assessment of multiple domains of pain following BNT162b2 mRNA COVID-19 vaccination.

Pain at the injection site is the most frequent reaction among COVID-19 vaccine recipients, but its characteristics were not fully described yet. The purpose of this study was to investigate multiple domains of pain following BNT162b2 mRNA vaccination. We included 107 subjects undergoing primary shot of the vaccination twice into deltoid muscle with a 3-week interval. They completed 6 sessions of pain assessments, one before the first and second dose (1-0, 2-0), and 1st/7th day after the first and second dose (1-1/1-7, 2-1/2-7). Pain visual analog scale (VAS), pain distribution, and pressure pain threshold (PPT) on deltoid muscle were evaluated in each session. The mean VAS (at rest/shoulder motion) was 6.0/27.6 mm at 1-1, and 12.8/34.0 mm at 2-1. Approximately, 90% of recipients showed localized pain within the upper arm. Percentage change of PPTs at 1-1 and 2-1 was bilaterally (ipsilateral/contralateral) decreased to 87.4/89.4% and 80.6/91.0%, which was recovered to the baseline level at 1-7 and 2-7. Temporary, mild-to-moderate intensity, localized distribution, concomitant with bilateral mechanical hyperalgesia on the deltoid muscle, were typical pain characteristics following this vaccination. These findings provide a rationale that will be informative for future recipients. J. Med. Invest. 70 : 355-360, August, 2023.

Staphylococcus aureus nasal colonization increases the risk of cedar pollinosis.

Background: One-third of the people in Japan are colonized with Staphylococcus aureus (S. aureus) and suffer from virulence factor-mediated subclinical inflammation of the nares. We investigated whether subclinical inflammation contributed to cedar pollinosis affecting 20 million people annually. Methods: The study participants were 814 inhabitants of the A or B prefectures. We compared the colonization rate and population structure of S. aureus, in association with the prevalence of cedar pollinosis, between participants in these two areas. Results: A prefecture had twice the annual amount of airborne cedar pollen compared with B. The prevalence of cedar pollinosis was significantly higher in A (23.5%) than in B (13.1%) (p = 0.0004). Moreover, the prevalence of cedar pollinosis was higher in female participants (23.3%) than in male participants (14.7%) (p = 0.003). In addition, the prevalence of cedar pollinosis was higher in S. aureus carriers (24.2%) than in S. aureus noncarriers (17.9%) (p = 0.03). The isolation rate of clonal complex (CC) 508 was higher in the A group (21%) than in the B group (7%) (p = 0.015). Conclusion: Nasal colonization of S. aureus is a major risk factor for cedar pollinosis. However, the direct mechanism of this risk is currently unknown.

Validation of the "My Headache Checker" that includes osmophobia in the diagnosis of migraine.

BACKGROUND: Migraine is a common headache disorder, with a 1 year prevalence rate of 6.0 %. However, less than 10% of patients with migraine receive medication in hospital. "My Headache Checker," a brief and self-administered migraine screening tool, which includes osmophobia in addition to the ID-Migraine™ three-item subset, was developed. The objective of this study was to analyze the applicability of "My Headache Checker" in Japanese patients. METHODS: A total of 238 patients visiting the outpatient department were enrolled in the study. The patients' chief complaint was not headache. "My Headache Checker" was administered to the patients. Subsequently, they were evaluated by a generalist for the diagnosis of headache. The clinical diagnosis of headache was determined based on the International Classification of Headache Disorders Ⅲ. RESULTS: Twenty (8.4%) patients satisfied the criteria for the diagnosis of migraine. Sensitivity, specificity, positive predictive value, and negative predictive value of "My Headache Checker" were 0.90, 0.83, 0.69, and 0.95, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of the ID-Migraine™ were 0.90, 0.85, 0.72, and 0.95, respectively. CONCLUSION: The majority of migraine patients are missed in busy outpatient departments. Our results suggest that "My Headache Checker" is a useful tool in diagnosing unrecognized migraine patients. However, the addition of osmophobia did not contribute to improve the screening power of the ID-Migraine™.

Impact of repeated yearly vaccination on immune responses to influenza vaccine in an elderly population.

BACKGROUND: The effectiveness of repeated vaccination for seasonal influenza remains controversial. Here, we measured antibody responses to the influenza virus (A/H1N1, A/H3N2 and B) in a closed cohort of older participants vaccinated against influenza virus in each of 5 consecutive years. METHODS: One hundred and 11 volunteers aged >61 years were vaccinated subcutaneously with 1 dose (0.5 ml) of inactivated influenza vaccine as recommended by the World Health Organization from the 2005-2006 season through the 2009-2010 season. Hemagglutination inhibition (HI) antibody titers were determined. RESULTS: HI antibody titers against all 3 virus strains were significantly higher at 4 weeks after vaccination than at a time point prior to vaccination in each of the 5 seasons (P < .01); HI antibody titers were detected at the original prevaccination levels just prior to re-vaccination the following year. Sero-protection and HI antibody titers at 4 weeks after vaccination were similar against all influenza strains and during most of the 5 seasons evaluated. Vaccine strain changes were associated with specific immune responses in 9 of 12 (75%) intervals. CONCLUSIONS: Taken together, our results suggest that annual vaccination is necessary to maintain humoral immunity for the elderly population. Furthermore, our findings revealed that annual seasonal vaccination was not associated with reduced vaccine effectiveness, and that the reformation of the vaccine resulted in amplified immune responses among those undergoing yearly vaccination in the elderly population.

Prevalence and characteristics of methicillin-resistant Staphylococcus aureus colonization among healthcare professionals in a university hospital in Japan.

BACKGROUND: Asymptomatic carriers of methicillin-resistant Staphylococcus aureus (MRSA) are important sources of nosocomial transmission. MRSA may be transmitted from hospitalized patients to healthcare professionals and vice versa. METHODS: The prevalence of MRSA colonization among forty-five healthcare professionals in a Japanese hospital was determined by performing surveillance cultures to identify unrecognized carriers of MRSA. All MRSA isolates were evaluated using multilocus sequence typing (MLST) to identify the transmission routes. RESULTS: The proportion of MRSA colonization was significantly higher in healthcare professionals (11.1%) than in community residents (0.72%; P < 0.0001) or admission case (2.5%; P = 0.018). MLST analysis revealed that both the ST8 and ST764 strains were identified in residents, patients, and healthcare professionals. MRSA colonization was more frequently observed among physicians (4/13; 31%) than nurses (1/32; 3%) (P = 0.020). CONCLUSION: Multilocus sequence typing results suggest that ST8 and ST764 are involved in the occurrence of nosocomial MRSA infections. These findings emphasize the necessity for the effective education of physicians to prevent MRSA transmissions.

Transmission of methicillin-resistant Staphylococcus aureus in an acute care hospital in Japan.

BACKGROUND: Asymptomatic carriers of methicillin-resistant Staphylococcus aureus (MRSA) are important sources of nosocomial transmission. However, the route of transmission of MRSA is not completely understood. The purpose of this study was to calculate MRSA transmission rates in a hospital with a high MRSA infection/colonization density and inadequate hand hygiene compliance. METHODS: The prevalence of MRSA colonization among 157 patients at the time of admission to and discharge from a medical school hospital in Japan was determined by performing surveillance cultures. All MRSA isolates were evaluated using multilocus sequence typing (MLST) to identify the transmission routes. RESULTS: Methicillin-resistant S. aureus was prevalent in 1.9% of our study population. MRSA was acquired during hospitalization at a rate of 4.0/1000 patient-days. At discharge, 5.1% of the patients exhibited MRSA colonization; this was significantly higher than the prevalence noted upon admission (P < 0.001). MLST documented three possible nosocomial transmission events. MRSA colonization was detected using surveillance cultures prior to being identified by conventional, clinically oriented examinations. CONCLUSIONS: Multilocus sequence typing results suggested that patients who were colonized with MRSA acquired it during hospitalization. These results reinforce the importance of infection control for preventing nosocomial MRSA transmission in hospitalized patients.

Prevalence and characteristics of methicillin-resistant Staphylococcus aureus in community residents of Japan.

BACKGROUND: To implement effective precautions to avoid methicillin-resistant Staphylococcus aureus (MRSA) nosocomial infections, it is important to clarify when, how, and from whom MRSA was transmitted to the patients. However, MRSA strains obtained from outpatient population were not analyzed, and the transmission routes of MRSA in the community are not completely understood. The purpose of this study was to clarify whether MRSA is spreading in community settings or whether MRSA transmission still occurs only in healthcare institutions. METHODS: Surveillance cultures of 1274 residents living in a community were performed in two different areas, Kochi and Osaka prefectures of Japan. All isolated MRSA strains were evaluated using multilocus sequence typing (MLST) to clarify the transmission routes of MRSA. The results were compared with those of inpatients. Moreover, written questionnaires and medical records were analyzed. RESULTS: Analysis of surveillance cultures from residents living in the community in Japan revealed an MRSA colonization rate of 0.94%. The proportion of MRSA to S. aureus colonization was 2.6% in the 310 residents, which was significantly lower than in the 393 hospitalized patients (63.1%; P < .0001). MRSA strains in residents are different from the endemic strains in the hospitalized patients. Previous hospital admission is a risk factor for MRSA infection of the endemic strain in hospital. CONCLUSIONS: Methicillin-resistant Staphylococcus aureus colonization in community setting is rare in Japan. MLST results suggest that some MRSA strains are moving to the community through previous hospital admissions; however, MRSA is not spreading in community settings.

Poor survival of Methicillin-resistant Staphylococcus aureus on inanimate objects in the public spaces.

We investigated the prevalence of Staphylococcus aureus on shopping baskets in Osaka Prefecture, Japan. Multilocus sequence typing was performed to determine the genotypes of S. aureus isolates, and then a polymerase chain reaction method was used to detect staphylococcal enterotoxins and antibiotic resistance genes. In addition, desiccation tolerance of S. aureus isolates was evaluated in vitro. Forty-six (6.2%) S. aureus isolates were collected from 740 shopping baskets, though only one MRSA strain was identified. In multilocus sequence typing findings, ten sequence types and 24 singletons were classified, which were divided into ten clonal complexes and six singletons. The most frequent staphylococcal enterotoxin gene was seg (30.4%). Our in vitro findings demonstrated that 70% of the S. aureus isolates, including the MRSA strain, became undetectable at 12 h after desiccation at an appropriate cell density, while the others remained viable for up to 24 h. Thus, it is difficult for MRSA organisms to survive on dry surfaces found in public areas. We speculated that inanimate objects in the community are unlikely to be a potential source for transmission of MRSA and that S. aureus on such objects outside of hospital settings is not a public health threat.

Allelotype analysis in relapsed childhood acute lymphoblastic leukemia.

We performed for the first time the allelotype of relapsed childhood acute lymphoblastic leukemia (ALL). A total of 38 cases were screened for loss of heterozygosity (LOH) using 71 markers. In all, 26 (68%) patients showed LOH on at least one chromosomal arm, indicating that LOH is a frequent event at relapse. The most frequent loss was found on chromosomal arm 9p at the p16/INK4a locus (39%). LOH at the TEL gene locus on chromosomal arm 12p also occurred often (25%). Frequent loss was observed on chromosome arms 4q (20%), 6q (21%), and 17q (20%). Sequential analysis (i.e. samples obtained from both initial diagnosis and relapse) shows that some patients (63%) have the identical LOH status at both phases, suggesting the presence of the same clone. Other samples (37%) showed distinct LOH alterations, indicating clonal evolution at relapse. Despite the heterogeneous and complex changes, some shared LOH loci occurred in these matched samples, suggesting that many of the same tumor-suppressor genes are aberrant at both phases. In summary, novel tumor-suppressor genes on chromosome arms 4q, 6q, and 17q, as well as the p16 and TEL genes, have an important role in the relapse of childhood ALL.

Methylation analysis of the adenomatous polyposis coli (APC) gene in adult T-cell leukemia/lymphoma.

We investigated methylation status of the adenomatous polyposis coli (APC) gene in adult T-cell leukemia/lymphoma (ATL). APC methylation was found in 15 of 31 (48%) primary samples, and 2 of 4 (50%) ATL cell lines. Methylation of the APC gene occurred more frequently in acute ATL (12/21) (57%) than chronic ATL (1/8) (13%) (P = 0.03). APC was not expressed in the APC-methylated ATL cell line ST1. Demethylation with 5-azacytidine treatment restored APC expression in the ST1 cell line. Our data show that hypermethylation of the APC gene is involved in the pathogenesis of ATL.

Methylation of the MLH1 gene in hematological malignancies.

Hypermethylation of the MLH1 gene has been described in many kinds of human cancers with microsatellite instability (MSI). However, it is not clear whether the same mechanism occurs in hematological malignancies. Genomic DNA was extracted from 31 patients with adult T-cell leukemia/lymphoma (ATL), 9 patients with acute lymphoblastic leukemia (ALL) who had MSI, and 12 leukemia and lymphoma cell lines with MSI. Aberrant methylation of the MLH1 gene was found in 2/31 (6%) ATL patients, and in 1/12 (8%) cell lines with MSI. MLH1 promoter was not methylated in either of the twelve peripheral blood samples from normal individuals or ALL samples. The MLH1 gene was expressed in the normal peripheral blood samples, but not in the MLH1-methylated cell line KCL22. Demethylation with 5-Azacytidine treatment restored MLH1 expression in the KCL22 cell line. Methylation of the MSH2 gene was not found in any of the samples. Our data show that hypermethylation of the MLH1 gene is occasionally involved in the pathogenesis of hematological malignancies, but is not always associated with MSI.

Allelic loss during progression of follicular lymphoma.

We performed loss of heterozygosity (LOH) analysis on matched lymph nodes before and after progression of follicular lymphoma (FL), and found novel LOH on chromosome arm 12p. This LOH has not been previously reported in association with FL transformation. Other sites of frequent LOH include chromosome arms 6q and 9p. LOH was observed in both transformed FL and relapse FL. These data suggest that altered tumor suppressor genes exist on 6q, 9p, and 12p that have an important role in the progression of FL. Genetic changes accumulated in relapsed FL in the absence of histological changes compared to initial diagnosis.

Methylenetetrahydrofolate reductase genotype does not play a role in adult T-cell leukemia/lymphoma pathogenesis among human T-lymphotrophic virus type 1 carriers.

Human T-lymphotropic virus type 1 (HTLV-1) is associated with adult T-cell leukemia/lymphoma (ATL). However, the incidence of ATL is low among HTLV-1 carriers suggesting additional mechanisms are involved in the progression of the disease. A recent study found that polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene influence the susceptibility to malignant lymphoma. We have analyzed the MTHFR genotype in 81 HTLV-1 carriers and 87 ATL patients. No statistically significant associations were found between MTHFR genotype and development of ATL. These data suggest that genetic polymorphisms in the MTHFR locus do not play a role in ATL pathogenesis among HTLV-1 carriers.

Mutations in the retinoblastoma-related gene RB2/p130 in adult T-cell leukaemia/lymphoma.

The retinoblastoma (Rb) family consists of the tumor suppressor Rb/p105 and related proteins p107 and Rb2/p130. Although the involvement of the RB/p105 gene in Adult T-cell leukaemia/lymphoma (ATL) has been studied, no mutational data is reported regarding the RB2/p130 gene in ATL. We screened for mutations of the RB2/p130 gene. Mutation was detected in 1 of 41 primary ATL sample. This is the first report describing mutation of the RB2/p130 gene in ATL, suggesting that RB2/p130 may be involved in the development of ATL, and may behave as a tumor suppressor gene in T lymphocytes.

Aberrant methylation in promoter-associated CpG islands of multiple genes in relapsed childhood acute lymphoblastic leukemia.

Methylation profile was analyzed in nine cases of relapsed childhood acute lymphoblastic leukemia (ALL) for p14, p15, p16, Rb, MGMT, APC, hMLH1, RARbeta, RIZ, DAPK, and FHIT genes by using methylation specific polymerase chain reaction (MSP) analysis. Frequency of methylation in each gene was: MGMT, 56%; RARbeta, 44%; and p16, 22%, respectively. None of the p14, p15, Rb, APC, hMLH1, RIZ, DAPK, and FHIT genes were hypermethylated. Five (56%) of 9 cases showed methylation of at least one gene. All of the samples with hypermethylation in p16 and MGMT gene at relapse, had already acquired the change at the time of initial diagnosis. Interestingly, three of 4 cases with RARbeta gene methylation at relapse did not have methylation of this gene at the time of initial presentation. These results suggest that hypermethylation might be involved in the relapse of childhood ALL.

Academic performance and comparative effectiveness of computer- and textbook-based self-instruction.

We intended to clarify the influence of student academic ability on the effectiveness of CAI, using data of a study to assess the effectiveness of a new type of CAI software, cyberPatient (CP), at Kochi Medical School (KMS). A total of 59 third-year students were randomly assigned to four groups: Group-1 used a textbook for self-instruction, Group-2 used CP, Group-3 used both types of learning materials, and Group-4 did not learn. Learning performance was evaluated by multiple-choice examination and OSCE. In order to clarify the influence of students' academic ability on the effectiveness of CAI, statistical analyses were conducted, assigning students as either high or medium or low performance students. High performance students from Group-1, -2 and -3 did not differ significantly in test performance after self-instruction. However, low performance students in Group-1 scored significantly lower than those in Group-2 and -3. All students in Group-2 and -3 reported that CP stimulated willingness to learn and assisted understanding. The present analysis suggested that effectiveness of CAI might be associated with the academic ability of students.

Prevaccination antibody titers can estimate the immune response to influenza vaccine in a rural community-dwelling elderly population.

Influenza and its complications are related to increased morbidity and mortality in elderly persons. Influenza vaccination is an important strategy to minimize the excess morbidity and mortality caused by influenza infection. Influenza epidemics start in November and continue to March in the next year, but it is not clear if the immunization-induced antibody titer lasts throughout the influenza season. One hundred eighty-two rural community-dwelling elderly persons older than 61 years were immunized with one dose of influenza vaccine in the 2005-2006 influenza season, and the antibody response after vaccination was investigated. Both the antibody titers and seroprotection rates were significantly higher four weeks after the vaccination but decreased markedly at 22 weeks after the vaccination. Analysis of the factors affecting the antibody response showed that those who have a low antibody titer before vaccination ('seronegative') do not acquire enough antibody with one dose of influenza vaccine. Neither age nor vaccination in the previous year was related to the antibody response after vaccination. These findings suggest that future clinical trials should be performed to determine if a second booster vaccination maintains the titer.

Effect of age on chronological variation of acute myocardial infarction onset: study in Japan.

To evaluate the effect of age on circadian and seasonal variation in the onset of acute myocardial infarction (AMI) in Japan, we studied 725 patients whose onset date and time of the symptom were determined. In the analysis of all AMI patients, the occurrence showed significant circadian variation (P< 0.01); 30% of episodes occurred between 0600 and 1200h which formed a dominant morning peak. In the analysis of separate age-groups, a significant difference in the occurrence among four 6-hour periods of day was observed only in the early-elderly group (65-74 years), in which a significant (P < 0.01) morning peak comprising 33% of episodes was observed between 0600 and 1200 h. The monthly variation of AMI onset in total subjects tended to show two peaks; April and August. The seasonal variation tended to show a trough in autumn when analyzed in all patients, but the variation was significant only in middle-aged group (< 65 years). In conclusion, the incidence of AMI in Japanese population showed dominant morning peak, and tended to show autumn trough. These circadian and seasonal variations were affected by age.