Kyushu University · Medicine
Professor Yong Chong's research lab specializes in clinical immunology and infectious diseases, with a focus on age-related immune senescence, antimicrobial resistance, and host-pathogen interactions in vulnerable populations. The lab investigates B cell dysfunction in aging and HIV infection, evaluates the epidemiology and resistance patterns of multidrug-resistant bacteria such as ESBL-producing E. coli and S. maltophilia, and examines the impact of antibiotic prophylaxis in neutropenic patients. Their work integrates flow cytometry, microbiological surveillance, and clinical data to inform infection management and public health strategies.
Figures are computed from collected data and may differ slightly.
To investigate age-related alterations in human humoral immunity, we analyzed the quantity and quality of peripheral B cell subsets, CD27-negative (CD27(-)) and CD27-positive (CD27(+)) B cells, by flow cytometry analysis in 54 aged individuals (mean age +/- SE, 74.6 +/- 0.7 years) and 30 young individuals (mean age +/- SE, 26.1 +/- 0.5 years). CD27(-) and CD27(+) B cells are regarded as naive and memory B cells, respectively. CD38, Ki-67, CD95 and bcl-2 were used as activation, proliferation and
Community-acquired infections caused by extended-spectrum β-lactamase (ESBL)-producing bacteria, particularly CTX-M-producing Escherichia coli, are a rising concern worldwide. There are few data from Japan on the acquisition of ESBLs in the community or the influx of these bacteria into hospitals. Therefore, we examined the prevalence of ESBL carriage in outpatients, in order to estimate the spread of ESBLs in community settings. We analysed bacterial isolates from outpatient samples at our inst
The routine use of fluoroquinolone prophylaxis in patients with neutropenia and hematological malignancies is controversial. This prophylaxis has been reported to have a positive impact in reducing infection-related mortality, but the consequent development of antibiotic resistance has become a concern. This study assessed the effect of discontinuing quinolone prophylaxis on the etiology and the resistance pattern of blood culture isolates and on the prognosis among febrile neutropenic patients
To investigate HIV-1-related B cell disorders, the quantity of CD27 positive (CD27+) B cells and their CD38, CD95, and bcl-2 intensities were examined by flow cytometry analysis in 16 drug-naive patients, 27 highly active antiretroviral therapy (HAART)-treated patients, and 20 uninfected controls. CD27+ B cells have been recognized as memory B cells. The mean percentage of CD27+ B cells was significantly lower in drug-naive patients (11.9%) and in HAART-treated patients (16.1%) than in controls
Stenotrophomonas maltophilia is an important nosocomial bacterial pathogen, as is Pseudomonas aeruginosa. Differentiation of these bacteria as bacteremic agents is critical in the clinical setting and to define a therapeutic strategy; however, the associated factors and prognosis for S. maltophilia bacteremia have not been fully evaluated to adequately characterize these factors. We first conducted a matched case-control study to clarify these questions. A total of 30 case patients with S. malto
Cefepime resistance was often detected in the blood culture isolates from febrile neutropenic patients. This result suggests that therapeutic strategies for febrile neutropenia should be modified based on the local antibiotic resistance patterns.
To investigate age-related alterations in human humoral immunity, we analysed Ig heavy chain variable region genes expressed by peripheral B cells from young and aged individuals. Three hundred and twenty-seven cDNA sequences, 163 micro and 164 gamma transcripts with VH5 family genes, were analysed for somatic hypermutation and VHDJH recombinational features. Unmutated and mutated micro transcripts were interpreted as being from naive and memory IgM B cells, respectively. In young and aged indiv
To investigate HIV-1-related B cell disorders, the quantity of peripheral CD27 negative (CD27-) B cells, their CD38, CD95, and bcl-2 intensities, and their apoptosis susceptibility were examined by flow cytometry analysis in 16 drug-naive patients, 27 HAART-treated patients, and 20 uninfected controls. CD27- B cells have been recognized as naive B cells. The mean percentage of CD27- B cells was significantly higher in drugnaive patients (88.1%) and in HAART-treated patients (83.9%) than in contr
We implemented a monthly rotation of primary antibiotics for febrile neutropenic patients. An antibiotic heterogeneity strategy, mainly performed as a cycling regimen, would be useful for controlling antimicrobial resistance among patients treated for febrile neutropenia.
These findings suggest that an AZM-containing regimen may be the better initial treatment choice for MAC-LD as it resulted in lesser discontinuation rates attributed to adverse events while offering similar patient outcomes when compared with CLR.
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