Background: Understanding the virulence and pathogenicity of invasive nontyphoidal Salmonella (iNTS) in children may support timely treatment and enable closer monitoring of chronic infections. iNTS epidemiology in Asia remains inadequately described. We analyzed the genetic diversity and virulence genes associated with extra-intestinal invasion in Korean children. Methods: Salmonella isolates from children < 18 yrs of age diagnosed with moderate-tosevere salmonellosis between January 2019 and December 2021 were subjected to antibiotic susceptibility testing and whole-genome sequencing. Results: In total, 58 cases were included. We identified 20 serotypes, the most prevalent being Salmonella Enteritidis (N = 21), followed by Infantis (N = 6), I 4,[5],12:i:- (N = 5), and Bareilly (N = 5). Extra-intestinal invasion occurred in 12 (20.7%) cases involving Salmonella Oranienburg (2/2), Give (1/1), Javiana (1/1), Paratyphi B var. L(+) tartrate+ (1/1), Schwarzengrund (1/1), Singapore (1/1), Montevideo (1/2), Saintpaul (1/2), I 4:b:- (1/2), Infantis (1/6), and Enteritidis (1/21). While the numbers of total virulence genes and genes belonging to major virulence categories did not significantly differ between iNTS and noniNTS, several genetic factors, including Salmonella pathogenicity island (SPI)-1 (P = 0.039), SPI-2 (P = 0.020), SPI-5 (P = 0.014), SPI-13 (P = 0.010), cytolethal distending toxin-related genes (P = 1.4 × 10 –4 ), fepC (P = 0.021), and tcpC (P = 0.040) were more frequent in invasive isolates. Conclusions Salmonella Enteritidis-ST11 predominated in infections among Korean children, but invasive isolates were rare. Early detection of genetic factors associated with extra-intestinal invasion will be helpful for prompt and appropriate treatment.

Scrub typhus, a mite-borne infectious disease, is caused by Orientia tsutsugamushi. Despite many attempts to develop a protective strategy, an effective preventive vaccine has not been developed. The identification of appropriate Ags that cover diverse antigenic strains and provide long-lasting immunity is a fundamental challenge in the development of a scrub typhus vaccine. We investigated whether this limitation could be overcome by harnessing the nanoparticle-forming polysorbitol transporter (PST) for an O. tsutsugamushi vaccine strategy.Two target proteins, 56-kDa type-specific Ag (TSA56) and surface cell Ag A (ScaA) were used as vaccine candidates. PST formed stable nano-size complexes with TSA56 (TSA56-PST) and ScaA (ScaA-PST); neither exhibited cytotoxicity. The formation of Ag-specific IgG2a, IgG2b, and IgA in mice was enhanced by intranasal vaccination with TSA56-PST or ScaA-PST. The vaccines containing PST induced Ag-specific proliferation of CD8 + and CD4 +T cells. Furthermore, the vaccines containing PST improved the mouse survival against O.tsutsugamushi infection. Collectively, the present study indicated that PST could enhance both Ag-specific humoral immunity and T cell response, which are essential to effectively confer protective immunity against O. tsutsugamushi infection. These findings suggest that PST has potential for use in an intranasal vaccination strategy.

The gastrointestinal tract is the first organ directly affected by fasting. However, little is known about how fasting influences the intestinal immune system. Intestinal dendritic cells (DCs) capture antigens, migrate to secondary lymphoid organs, and provoke adaptive immune responses. We evaluated the changes of intestinal DCs in mice with short-term fasting and their effects on protective immunity against Listeria monocytogenes(LM). Fasting induced an increased number of CD103 + CD11b − DCs in both small intestinal lamina propria (SILP) and mesenteric lymph nodes (mLN). The SILP CD103 + CD11b − DCs showed proliferation and migration, coincident with increased levels of GM-CSF and C-C chemokine receptor type 7, respectively. At 24 h post-infection with LM, there was a significant reduction in the bacterial burden in the spleen, liver, and mLN of the short-term-fasted mice compared to those fed ad libitum. Also, short-term-fasted mice showed increased survival after LM infection compared with ad libitum-fed mice. It could be that significantly high TGF-β2 and Aldh1a2 expression in CD103 + CD11b - DCs in mice infected with LM might affect to increase of Foxp3 + regulatory T cells. Changes of major subset of DCs from CD103 + to CD103 - may induce the increase of IFN-γ–producing cells with forming Th1-biased environment.Therefore, the short-term fasting affects protection against LM infection by changing major subset of intestinal DCs from tolerogenic to Th1 immunogenic.

Purpose: Drug-coated balloons have shown successful results in treating peripheral arterial occlusive disease. However, using multiple balloons for long femoropopliteal lesions (>15 cm) remains challenging; their safety and efficacy need to be explored. Therefore, we aimed to evaluate the outcomes of multiple drug-coated balloons for long femoropopliteal lesions in terms of the primary patency, freedom from clinically-driven target lesion revascularization, and mortality. Methods: Between April 2015 and September 2018, 96 patients (117 limbs) who underwent balloon angioplasty using at least 2 drug-coated balloons for femoropopliteal lesions were retrospectively reviewed. Lesions were classified as TransAtlantic Inter-Society Consensus (TASC) classification C or D. The outcomes were analyzed using Kaplan-Meyer analysis. Results: The mean age of 96 enrolled patients was 70.8 ± 9.8 years, and 83 patients were males (86.5%). Critical limbthreatening ischemia was found in 29 cases (24.8%). The mean lesion and drug-coated balloon lengths per limb were 292.3 ± 77.8 mm and 325.0 ± 70.2 mm, respectively. The technical success rate was 99.2%. A total of 82.1% were followedup for more than 6 months. The primary patency rates at 12 and 24 months were 71.4% and 41.7%, respectively; freedom from clinically-driven target lesion revascularization rates were 96.4% and 71.0% at 12 and 24 months, respectively. The Kaplan-Meier estimate of the 2-year overall cumulative mortality rate was 20.8%. All identified mortalities appeared to be less associated with paclitaxel. Conclusion Drug-coated balloons can be effectively used without drug-related mortality, even for long lesions, such as TASC classification C or D femoropopliteal lesions.

Scrub typhus develops after the individual is bitten by a trombiculid mite infected with Orientia tsutsugamushi. Since it has been reported that pneumonia is frequently observed in patients with scrub typhus, we investigated whether intranasal (i.n.) vaccination with the outer membrane protein of O. tsutsugamushi (OMPOT) would induce a protective immunity against O. tsutsugamushi infection. It was particular interest that when mice were infected with O. tsutsugamushi, the bacteria disseminated into the lungs, causing pneumonia. The i.n. vaccination with OMPOT induced IgG responses in serum and bronchoalveolar lavage (BAL) fluid. The anti-O. tsutsugamushi IgA Abs in BAL fluid after the vaccination showed a high correlation of the protection against O. tsutsugamushi. The vaccination induced strong Ag-specific Th1 and Th17 responses in the both spleen and lungs. In conclusion, the current study demonstrated that i.n. vaccination with OMPOT elicited protective immunity against scrub typhus in mouse with O. tsutsugamushi infection causing subsequent pneumonia.

Purpose: Drug-coated balloons have shown successful results in treating peripheral arterial occlusive disease. However, using multiple balloons for long femoropopliteal lesions (>15 cm) remains challenging; their safety and efficacy need to be explored. Therefore, we aimed to evaluate the outcomes of multiple drug-coated balloons for long femoropopliteal lesions in terms of the primary patency, freedom from clinically-driven target lesion revascularization, and mortality. Methods: Between April 2015 and September 2018, 96 patients (117 limbs) who underwent balloon angioplasty using at least 2 drug-coated balloons for femoropopliteal lesions were retrospectively reviewed. Lesions were classified as TransAtlantic Inter-Society Consensus (TASC) classification C or D. The outcomes were analyzed using Kaplan-Meyer analysis. Results: The mean age of 96 enrolled patients was 70.8 ± 9.8 years, and 83 patients were males (86.5%). Critical limbthreatening ischemia was found in 29 cases (24.8%). The mean lesion and drug-coated balloon lengths per limb were 292.3 ± 77.8 mm and 325.0 ± 70.2 mm, respectively. The technical success rate was 99.2%. A total of 82.1% were followedup for more than 6 months. The primary patency rates at 12 and 24 months were 71.4% and 41.7%, respectively; freedom from clinically-driven target lesion revascularization rates were 96.4% and 71.0% at 12 and 24 months, respectively. The Kaplan-Meier estimate of the 2-year overall cumulative mortality rate was 20.8%. All identified mortalities appeared to be less associated with paclitaxel. Conclusion Drug-coated balloons can be effectively used without drug-related mortality, even for long lesions, such as TASC classification C or D femoropopliteal lesions.

OBJECTIVES: Chigger mites are vectors for scrub typhus. This study evaluated the annual fluctuations in chigger mite populations and Orientia tsutsugamushi infections in South Korea.METHODS: During 2006 and 2007, chigger mites were collected monthly from wild rodents in 4 scrub typhus endemic regions of South Korea. The chigger mites were classified based on morphological characteristics, and analyzed using nested PCR for the detection of Orientia tsutsugamushi.RESULTS: During the surveillance period, the overall trapping rate for wild rodents was 10.8%. In total, 17,457 chigger mites (representing 5 genera and 15 species) were collected, and the average chigger index (representing the number of chigger mites per rodent), was 31.7. The monthly chigger index was consistently high (> 30) in Spring (March to April) and Autumn (October to November). The mite species included Leptotrombidium pallidum (43.5%), L. orientale (18.9%), L. scutellare (18.1%), L. palpale (10.6%), and L. zetum (3.6%). L. scutellare and L. palpale populations, were relatively higher in Autumn. Monthly O. tsutsugamushi infection rates in wild rodents (average: 4.8%) and chigger mites (average: 0.7%) peaked in Spring and Autumn.CONCLUSION: The findings demonstrated a bimodal pattern of the incidence of O. tsutsugamushi infections. Higher infection rates were observed in both wild rodents and chigger mites, in Spring and Autumn. However, this did not reflect the unimodal incidence of scrub typhus in Autumn. Further studies are needed to identify factors, such as human behavior and harvesting in Autumn that may explain this discordance.
Globus Pallidus ; Humans ; Incidence ; Korea ; Mites ; Orientia tsutsugamushi ; Polymerase Chain Reaction ; Rodentia ; Scrub Typhus ; Trombiculidae

BACKGROUND: The zoonotic disease Q fever is caused by Coxiella burnetii and usually affects high-risk human populations. We conducted a serological survey of dairy cattle farmers in Korea to determine seroreactivity and identify risk factors for C. burnetii infection. METHODS: This cross-sectional study included 1,824 of 7,219 dairy cattle farms (25.3%) in the study region. The selected dairy cattle farmers visited the nearest public health centers or branches with completed questionnaires. Serum samples from the farmers were tested using an indirect immunofluorescence assay to detect phase II C. burnetii immunoglobulin (Ig) G or M antibodies. RESULTS: A total of 1,222 dairy cattle farmers from 784 dairy cattle farms (43.0%) participated in this study, and 11.0% (134/1,222) exhibited seroreactivity, defined as a phase II antigen IgG or IgM titer ≥ 1:16. In the multivariate analysis, male sex, residence in Gyeonggi Province, a larger herd size, and ocular/oral contact with birth products during calf delivery were significantly associated with a higher risk of C. burnetii infection. Furthermore, the risk was significantly lower among farmers who always wore protective gloves while cleaning cattle excretion, compared to those who sometimes or rarely wore protective gloves. CONCLUSION: Dairy cattle farmers should exercise caution by avoiding ocular/oral contact with birth products during calf delivery and by using protective equipment (including gloves).
Agriculture ; Animals ; Antibodies ; Cattle* ; Coxiella burnetii* ; Coxiella* ; Cross-Sectional Studies ; Farmers* ; Fluorescent Antibody Technique, Indirect ; Gloves, Protective ; Gyeonggi-do ; Humans ; Immunoglobulin G ; Immunoglobulin M ; Immunoglobulins ; Korea* ; Male ; Multivariate Analysis ; Parturition ; Public Health ; Q Fever* ; Risk Factors* ; Serologic Tests ; Zoonoses

OBJECTIVES: Q fever is a zoonotic disease that occurs worldwide; however, little is known about its prevalence in South Korea. We attempted to determine the prevalence of Q fever seroreactivity among Korean slaughterhouse workers and the risk factors for seroreactivity according to the type of work. METHODS: The study was conducted among 1503 workers at a total of 73 slaughterhouses and 62 residual-product disposal plants. During the study period, sites were visited and surveys were administered to employees involved in slaughterhouse work, and serological tests were performed on blood samples by indirect immunofluorescence assays. Serological samples were grouped by job classification into those of slaughter workers, residual-product handlers, inspectors and inspection assistants, and grading testers and testing assistants. Employee risk factors were analyzed according to the type of work. RESULTS: Out of 1481 study subjects who provided a blood sample, 151 (10.2%) showed reactive antibodies. When these results were analyzed in accordance with the type of work, the result of slaughter workers (11.3%) was similar to the result of residual-product handlers (11.4%), and the result of inspectors and assistants (5.3%) was similar to the result of grading testers and assistants (5.4%). Among those who answered in the affirmative to the survey question, “Has there been frequent contact between cattle blood and your mouth while working?” the proportions were 13.4 and 4.6%, respectively, and this was identified as a risk factor that significantly varied between job categories among slaughterhouse workers. CONCLUSIONS: This study found a Q fever seroreactivity rate of 10.2% for slaughterhouse workers, who are known to be a high-risk population. Contact with cattle blood around the mouth while working was the differential risk factor between job categories among slaughterhouse workers.
Abattoirs* ; Animals ; Antibodies ; Cattle ; Classification ; Coxiella burnetii ; Fluorescent Antibody Technique, Indirect ; Korea* ; Mouth ; Prevalence ; Q Fever* ; Risk Factors ; Serologic Tests ; Zoonoses