Incidence of Scarlet Fever in Children in Jeju Province, Korea, 2002-2016: An Age-period-cohort Analysis / 예방의학회지

OBJECTIVES: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. METHODS: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ≤14 years residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. RESULTS: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. CONCLUSIONS: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

Effects of lidocaine on peripheral blood mononuclear cells from patients with atopic dermatitis stimulated by the Staphylococcus aureus exotoxin TSST-1 / 中华皮肤科杂志

Objective To investigate the effect of lidocaine on Staphylococcus aureus exotoxin-stimulated peripheral blood mononuclear cells (PBMCs) from patients with atopic dermatitis (AD).Methods Peripheral blood samples were collected from 6 patients with AD,and PBMCs were isolated by a routine method.Then,the PBMCs were stimulated by the Staphylococcus aureus exotoxin toxic shock syndrome toxin-1 (TSST-1) in the absence or presence of lidocaine at varying concentrations.The 3H-TdR incorporation method was performed to detect the proliferation of monocytes,and enzyme-linked immunosorbent assay (ELISA) to quantify the levels of T helper type 1 (Th1) and Th2 cytokines released by PBMCs.Human HaCaT keratinocytes were co-cultured with lidocaine-and TSST-1-stimulated PBMCs from patients with AD for 72 hours,then,Western blot was conducted to examine the expression of filaggrin protein in HaCaT cells.Results TSST-1 (100 μg/L) significantly enhanced the proliferation of PBMCs from patients with AD (stimulation index =75 ± 2.12,P ＜ 0.05),as well as the release of tumor necrosis factor-α (TNF-α),interferon (IFN)-γ,interleukin (IL)-2,IL-12,IL-4,IL-5 and IL-13 by the PBMCs (all P ＜ 0.05).Compared with the blank control group,100 μmol/L lidocaine significantly inhibited the TSST-1-stimulated proliferation of PBMCs from patients with AD (stimulation index =58 ± 3.14,P＜ 0.05),as well as the release of IL-4,IL-5,IL-13,TNF-α and IFN-γ by the stimulated PBMCs (all P ＜ 0.05).Western blot showed that 100 μmol/L lidocaine significantly blocked the down-regulation of filaggrin expression in HaCaT cells (P ＜ 0.01).Conclusion Lidocaine has a significant inhibitory effect on the activation of TSST-1-stimulated PBMCs from patients with AD.

Antibiotic susceptibilities, streptococcal pyrogenic exotoxin gene profiles among clinical isolates of group C or G Streptococcus dysgalactiae subsp. equisimilis & of group G S. anginosus group at a tertiary care centre.

Background & objectives: Group C and group G streptococci (together GCGS) are often regarded as commensal bacteria and their role in streptococcal disease burden is under-recognized. While reports of recovery of GCGS from normally sterile body sites are increasing, their resistance to macrolides, fluoroquinolone further warrants all invasive β haemolytic streptococci to be identified to the species level and accurately tested for antimicrobial susceptibility. This study was aimed to determine the prevalence, clinical profile, antimicrobial susceptibility and streptococcal pyrogenic exotoxin gene profile (speA, speB, speC, speF, smeZ, speI, speM, speG, speH and ssa) of GCGS obtained over a period of two years at a tertiary care centre from north India. Methods: The clinical samples were processed as per standard microbiological techniques. β-haemolytic streptococci (BHS) were characterized and grouped. Antimicrobial susceptibility of GCGS was performed using disk diffusion method. All GCGS were characterized for the presence of streptococcal pyrogenic exotoxins (spe) and spe genes were amplified by PCR method. Results: GCGS (23 GGS, 2GCS) comprised 16 per cent of β haemolytic streptococci (25/142 βHS, 16%) isolated over the study period. Of the 25 GCGS, 22 (88%) were recovered from pus, two (8%) from respiratory tract, whereas one isolate was recovered from blood of a fatal case of septicaemia. Of the total 23 GGS isolates, 18 (78%) were identified as Streptococcus dysgalactiae subsp equisimilis (SDSE, large-colony phenotype), five (21%) were Streptococcus anginosus group (SAG, small-colony phenotype). The two GCS were identified as SDSE. All GCGS isolates were susceptible to penicillin, vancomycin, and linezolid. Tetracycline resistance was noted in 50 per cent of SDSE isolates. The rates of macrolide and fluoroquinolone resistance in SDSE were low. Twelve of the 20 SDSE isolates were positive for one or more spe genes, with five of the SDSE isolates simultaneously carrying speA+ speB+ smeZ+ speF or speB+ smeZ+speF, speI+speM+speG+speH or, speI+spe M+speH or speA+ speB+ speC+ smeZ+ speF. One notable finding was the presence of spe B in four of the five isolates of the Streptococcus anginosus group. No isolate was positive for ssa. Interpretation & conclusions: Our study showed no association between GCGS isolates harbouring streptococcal pyrogenic exotoxins and disease severity. This might be attributed to the small sample size of spe-positive isolates.

Diferenciação de sorotipos de Actinobacillus pleuropneumoniae pela combinação de dois PCR multiplex / Differentiation of Actinobacillus pleuropneumoniae serotypes by the combination of two multiplex PCR

A pleuropneumonia suína é uma importante doença respiratória que ocasiona grandes perdas econômicas na suinocultura. O Actinobacillus pleuropneumoniae (APP) é o agente etiológico desta enfermidade que é classificado em 15 sorotipos. Estes secretam diferentes combinações das exotoxinas ApxI, ApxII, Apx III e ApxIV, que têm sido utilizadas na diferenciação dos sorotipos pela PCR multiplex (mPCR). A técnica descrita não permite a diferenciação dos sorotipos 2, 8 e 15 (apresentam mesmo padrão de amplificação) como também os sorotipos 12 e 13. Visando a melhorar a capacidade discriminatória desse procedimento, o presente trabalho descreve a combinação de um segundo mPCR baseado na amplificação de genes dos antígenos capsulares. O ensaio conjugado foi testado com cepas de referência pertencentes aos 15 sorotipos e também de 10 isolados de campo. A técnica proposta auxiliou na diferenciação dos 15 sorotipos testados (cepas de referência), como também proporcionou a identificação dos isolados de campo provenientes de casos clínicos, demonstrando que a técnica molecular é uma forma rápida e eficiente na identificação desse importante patógeno que afeta a criação de suínos, mesmo levando em consideração as limitações da técnica.

The swine pleuropneumonia is a major respiratory disease that causes great economic losses in pig farming. The Actinobacillus pleuropneumoniae (APP) is the etiologic agent of this disease and are classified into 15 serotypes. These secrete different combinations of exotoxins ApxI, ApxII, APX and ApxIV III have been used in the differentiation of serotypes by multiplex PCR (mPCR). The reported technique does not allow the differentiation of serotypes 2, 8 and 15 (exhibit same pattern of amplification) as well as serotypes 12 and 13. In order to improve the discriminatory capacity of this procedure, this paper describes the combination of a second mPCR based on amplification of genes of capsular antigens. The combined test was tested with reference strains belonging to 15 serotypes and also 10 field isolates. The proposed technique was capable of differentiating all 15 serotypes tested (reference strains), and was able to identify field isolates from clinical cases, demonstrating that the molecular technique is a quick and efficient identification of this important pathogen that affects the swine production. The proposed technique assisted in differentiating the 15 serotypes tested (reference strains), but also provided identification of field isolates from clinical cases, demonstrating that the molecular technique is a quick and efficient identification of this important pathogen that affects pig farming, even taking into account the limitations of the technique.

The expression of Panton-Valentine leukocidin gene and its correlation with agrA among different clinical isolates of Staphylococcus aureus / 中华检验医学杂志

Objective To investigate the correlation between expression of Panton-Valentine leukocidin gene and accessory gene regulator among different clinical isolates of Staphylococcus aureus.Methods All non-duplicate Staphylococcus aureus clinical isolates were isolated from various clinical specimens of the patients at 4 hospitals from January 2003 to December 2010.Panton-Valentine leukocidin genes among Staphylococcus aureus clinical isolates were detected by PCR and DNA sequencing.The expressions of lukS-PV and agrA were determined by real-time PCR.Results Ninty-six S.aureus isolates including 58 hospital-acquired and 28 community-acquired isolates were positive for PVL genes,among which 54 from blood,33 from pus and 9 from sputum.Ten isolates cannot be classified due to lack of information.Sixty-seven and 29 PVL-positive isolates were isolated from the specimens of adults and children.The median relative quantities of lukSmRNA of the isolates from pus and blood were 1.500 and 0.818.The quantity of lukSmRNA among the isolates from pus was significantly higher than that from blood (U =634,P =0.025).The median relative quantities of lukSmRNA of the isolates from children and adults were 1.292 and 0.540,respectively.The quantity of lukSmRNA among the isolates from children was significantly higher than that from adults (U =660,P =0.013).The median relative quantities of lukSmRNA among community-acquired and hospital-acquired isolates were 1.034 and 0.536,respectively.The quantity of lukSmRNA among community-acquired isolates was significantly higher than that from hospital-acquired isolates (U =338,P =0.012).The correlation coefficients between lukSmRNA and agrAmRNA of total isolates,pus isolates and blood isolates were 0.592 (P ＜ 0.01),0.810 (P ＜ 0.0l) and 0.543 (P ＜0.01),respectively.While the correlation coefficients of those among the isolates from children and adults were 0.804 (P ＜ 0.01) and 0.476 (P ＜ 0.01).The correlation coefficients of those among the isolates from community-acquired and hospital-acquired isolates were 0.767 (P ＜ 0.01) and 0.556 (P＜0.01).Conclusions The quantity of lukSmRNA of Staphylococcus aureus isolates from pus was significantly higher than that from blood.The agr may have positive regulation effect on the expression of lukS/F-PV,especially among the isolates from pus and children.(Chin J Lab Med,2013,36:313-317)

The Role of Superantigen in Nasal Polypogenesis

Superantigens are potent immunostimulatory exotoxins well known to be produced by Staphylococcus aureus (S. aureus). These exotoxins have capacity to act as superantigens by binding with the variable beta(Vbeta) region of lymphocytes in chronic rhinosinusitis with nasal polyposis, bypassing normal antigen processing and directly stimulating a massive inflammatory response. Accumulated evidence is now convincing that S. aureus superantigens may play an important role in development of chronic rhinosinusitis with nasal polyposis which are thought to skew the cytokine response towards a Th2 phenotype inducing eosinophilia and the production of polycolonal IgE. This review summarizes the current evidence of characteristics and its role superantigens in pathophysiology of nasal polyposis.

The Role of Superantigen in Nasal Polypogenesis

Superantigens are potent immunostimulatory exotoxins well known to be produced by Staphylococcus aureus (S. aureus). These exotoxins have capacity to act as superantigens by binding with the variable beta(Vbeta) region of lymphocytes in chronic rhinosinusitis with nasal polyposis, bypassing normal antigen processing and directly stimulating a massive inflammatory response. Accumulated evidence is now convincing that S. aureus superantigens may play an important role in development of chronic rhinosinusitis with nasal polyposis which are thought to skew the cytokine response towards a Th2 phenotype inducing eosinophilia and the production of polycolonal IgE. This review summarizes the current evidence of characteristics and its role superantigens in pathophysiology of nasal polyposis.

Toxic effect of exotoxin A of Pseudomonas aeruginosa on keratocytes / 吉林大学学报(医学版)

Objective To study the toxic effect of exotoxin A of Pseudomonas aeruginosa on keratocytes.Methods Three-dimensional gels of type I collagen containing rabbit keratocytes were incubated in the presence of different concentrations of exotoxin A(0.1,1.0,10 mg?L-1),cultivated for 24 h at 37℃,the change of keratocytes in morphology was observed under the light microscope,and the amount of lactate dehydrogenase(LDH) was measured by enzyme linked immunosorbent assay(ELISA).Results The LDH contents in different concentrations(0.1,1.0,10 mg?L-1)of exotoxin A groups were higher than that in the group without exotoxin A(P

Genetic Diversity and Exotoxin A Production of Group A Streptococci Causing Sepsis

The M protein and streptococcus pyrogenic exotoxin (SPE A) are important virulence factors in group A streptococci (GAS) infections. The emm types of GAS strains isolated from patients with sepsis were determined by sequencing the 5' N-terminus of the emm gene, encoding the M protein, and clonality analysis using pulsed-field gel electrophoresis. The presence of speA and production of SPE A were also examined. There were no predominant GAS clones. The emm genotypes were variable, and the most common genotype was emm13 (17.9%). The production prevalence of SPE A was 21.4%. The low mortality rate (7.1%) of GAS sepsis might be attributable to the low incidence of virulent strains such as emm1 (10.7%) and emm3 (7.1%), as well as to low production rate of SPE A.

Detection of Staphylococcus aureus-derived Exotoxins in Lesions of Childhood Atopic Dermatitis / 中华皮肤科杂志

Objectives To determine the prevalence of Staphylococcus aureus (S. Aureus) colonization and S. aureus-derived exotoxins in lesions of childhood atopic dermatitis (AD) and evaluate the role of S.aureus-derived exotoxins in the pathogenesis of childhood AD. Methods Specimens were taken from the skin lesions of 148 patients, non-lesional skin of 30 patients, and the skin of 250 controls for bacterial cultures. S. aureus-derived exotoxins were detected by reverse passive latex agglutination. Total IgE levels were determined with immunoradiometric assay. Results The prevalence of S. aureus colonization was significantly increased in both the lesional and non-lesional skin of patients with AD in comparison with the controls (P 0.05). However, patients with increased total IgE levels showed significantly high SCORAD indices (P