Associations between capsular serotype, multilocus sequence type, and macrolide resistance in Streptococcus agalactiae isolates from Japanese infants with invasive infections.

SUMMARY Streptococcus agalactiae (group B streptococcus; GBS) isolates (n = 150) from infants with invasive infections between 2006 and 2011 were analysed for capsular serotype, multilocus sequence type, and antibiotic susceptibility. In cases with late-onset disease (n = 115), primary meningitis was predominant (62.6%), but represented only 39.1% in cases with early-onset disease (n = 23). The most common serotype was III (58.7%), followed by Ia (21.3%) and Ib (12.7%). Sequence types (STs) of serotype III strains included ST17 (50.0%), ST19 (26.1%), ST335 (18.2%), ST27 (4.5%), and ST1 (1.1%). Predominant STs of serotypes Ia and Ib were ST23 (81.3%) and ST10 (84.2%), respectively. No penicillin-resistant strains were detected, but 22·0% of strains had mef(A/E), erm(A), or erm(B) genes, which mediate macrolide resistance. A new ST335, possessing an mef(A/E) gene belonging to clonal complex 19 gradually increased in frequency. Improved prevention of invasive GBS infections in infants requires timely identification, and ultimately vaccine development.

Influence of Th2 cells on hair cycle/growth after repeated cutaneous application of hapten.

Exposure to contact allergens in order to produce allergic contact dermatitis (ACD) seems to induce hair cycle/growth, but the mechanism of this remains unclear. In the current study, we investigated this mechanism and found that repeated application of hapten induced production of interleukin (IL)-4 in lymph-node immune cells. In addition, hair growth was induced in mice after the adoptive transfer of T-helper (Th)2 cells that had been purified from mice exposed to repeated cutaneous application of hapten. These findings lead us to speculate that Th2 cells that are repeatedly hapten-sensitized are recruited to hapten-challenged skin areas, and thus stimulate the production of IL-4 in the vicinity of the hair follicles, which influences hair cycle/growth. Our results may provide fundamental insights into the mechanism of contact hypersensitivity-induced hair cycle/growth.

Development of a loop-mediated isothermal amplification assay for rapid and simple detection of Erysipelothrix rhusiopathiae.

UNLABELLED: Erysipelothrix rhusiopathiae is a causative agent of swine erysipelas. We developed a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for sensitive and rapid detection of E. rhusiopathiae. The LAMP assay correctly detected 39 E. rhusiopathiae strains. No LAMP products were detected from 14 non-rhusiopathiae Erysipelothrix and 16 non-Erysipelothrix strains, including E. tonsillarum serovar 10 strains, which are difficult to be discriminated from E. rhusiopathiae strains. These results were consistent with those obtained by a conventional E. rhusiopathiae-specific PCR assay. Starting with DNA extraction from a single colony, the gel-based PCR assay took 4 h to provide a result, but the LAMP assay was faster, requiring only 37-80 min. The conventional culture test required more than 3-4 days to isolate and identify E. rhusiopathiae in the enrichment cultures. In contrast, the LAMP assay required less than 22 h from the beginning of the enrichment culture to final determination. These results suggest that the LAMP assay is useful as an adjunct to facilitate early diagnosis of swine erysipelas. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of a loop-mediated isothermal amplification (LAMP) assay for simple and cost-effective detection of E. rhusiopathiae from swine samples. The LAMP assay provided more rapid detection of the bacterium than conventional PCR and biochemical-based assays, and it may potentially facilitate surveillance and early diagnosis of swine erysipelas in the field.

Fungemia due to Rhodotorula mucilaginosa after allogeneic hematopoietic stem cell transplantation.

Rhodotorula species have been increasingly recognized as emerging pathogens, particularly in immunocompromised patients. We herein report on a patient with myelodysplastic syndrome who developed fungemia due to Rhodotorula mucilaginosa after allogeneic hematopoietic stem cell transplantation (HSCT) from an unrelated donor. He developed severe acute graft-versus-host disease requiring high-dose steroids, and had serially been administered fluconazole and micafungin for the prophylaxis of fungal infection. Although several cases of Rhodotorula infection after HSCT have been reported, all of them were recipients of autologous HSCT, not allogeneic HSCT. A review of all the reported cases of Rhodotorula infection after HSCT revealed that all patients had received fluconazole or echinocandins before the onset of infection. The findings suggest that Rhodotorula species could be causative yeasts, particularly in patients receiving fluconazole or echinocandins, both of which are inactive against the species.

Ictal SPECT of thalamocortical coupling in a patient with frontal absence.

Petit mal absence has been reported with 3-Hz generalized spike-and-wave discharges induced by secondary bilateral synchrony. Absence seizure may be present in patients with frontal lobe epilepsy. The thalamic rhythmogenic mechanisms responsible for spike-and-wave discharges have been investigated, providing a better understanding of the underlying anatomico-physiological mechanisms. We report the thalamocortical coupling in a patient with frontal absence by performing synchronous ictal single photon emission computed tomography (SPECT) analysis. Ictal SPECT revealed thalamic hyperperfusion combined with ipsilateral frontal cortical hyperperfusion in the patient. Moreover, lateral indexes of cerebral blood flow in the frontal region and thalamus were higher than those from non-epileptic control subjects. Thalamocortical coupling was thus revealed by ictal SPECT. Frontal absences should be considered as a secondarily generalized epilepsy syndrome originating from the frontal regions. The thalamus may play a crucial role as a pacemaker of rhythmic electroencephalographic activities such as secondary bilateral synchronous discharges in patients with frontal absences.

Increased circulating Th17 frequencies and serum IL-22 levels in patients with acute generalized exanthematous pustulosis.

BACKGROUND/OBJECTIVE: Acute generalized exanthematous pustulosis (AGEP) is a diffuse pustular disorder that usually begins in intertriginous folds with widespread erythema. The causes in the majority of the cases are drugs. T cells and interleukin (IL)-8 play roles in the development of AGEP, but the mechanism remains to be elucidated. We investigated the involvement of Th17 cells and their cytokine IL-22 in the pathogenesis. METHODS: Three patients with AGEP were enrolled in this study. The percentages of IL-17(+) Th17 cells, interferon γ(+) T cells and IL-4(+) T cells were measured in the patients' peripheral blood lymphocytes by intracellular cytokine staining and flow cytometry. The concentration of IL-22 in the sera was measured by enzyme-linked immunosorbent assay. RESULTS: The percentages of Th17 cells were markedly higher in all three patients than healthy control individuals. The frequencies of interferon γ(+) T cells were slightly high in the patients compared with the control, and there was no definite tendency in IL-4(+) T-cell frequencies. The concentration of IL-22 was remarkably high in all patients when compared with normal subjects with levels under detection. CONCLUSION: Th17 cells and their produced cytokine IL-22 were elevated in the peripheral blood of patients with AGEP. As IL-17 and IL-22 cooperatively stimulate keratinocytes to produce IL-8, IL-8 may contribute to the accumulation of neutrophils in the lesional epidermis of AGEP.

High-affinity receptor-mediated internalization and degradation of interleukin 2 in human T cells.

Receptor-mediated internalization and degradation of IL-2 were investigated in cell lines carrying human T cell leukemia/lymphoma (lymphotrophic) virus type I (HTLV-I) and PHA-treated normal PBL. The HTLV-I-carrying cell lines ILT-Yan and TL-Mor, and the PBL expressed both high- and low-affinity IL-2-R. However, another HTLV-I-carrying T cell line, MT-1, expressed mainly low-affinity receptors. Greater than 50% of the IL-2 bound to high-affinity receptors was internalized within 10 min when these cells were incubated at 37 degrees C. The internalized IL-2 was rapidly degraded and the products were excreted into the culture fluid. The t1/2 of IL-2 degradation in these cells was estimated as 60-80 min at 37 degrees C. The internalization and degradation of IL-2 were both temperature dependent. Light-microscopic autoradiography with 3H-labeled IL-2 confirmed the internalization of IL-2, and suggested that some IL-2 might be carried to the nucleus.

Ligation of VLA-4 on T cells stimulates tyrosine phosphorylation of a 105-kD protein.

The VLA/integrins are a family of heterodimeric adhesion receptors shown to be involved in cell-to-cell and cell-to-extracellular matrix (ECM) interactions. Given recent evidence that VLA molecules can synergize with the CD3/T cell receptor (TCR) pathway to activate T cells, it is important to identify biochemical event(s) generated by these molecules. Here, we report that the engagement of VLA-4 on T cells with specific antibodies or its ligand activates protein-tyrosine kinase (PTK) activity as detected by antiphosphotyrosine immunoblotting. The crosslinking of VLA-beta 1 (CD29) with a specific monoclonal antibody (mAb) (anti-4B4) plus anti-mouse immunoglobulin resulted in the rapid tyrosine phosphorylation of a 105-kD protein (pp105) in the human T cell line H9, as well as in peripheral resting T cells. The increase in tyrosine phosphorylation of pp105 was specifically mediated by VLA-4, since mAbs against alpha 4, but not against other VLA alpha chains, could induce this phosphorylation. In addition, the binding of T cells with the CS1 alternatively spliced segment of fibronectin (the binding site recognized by VLA-4) induced pp105 tyrosine phosphorylation. Crosslinking the CD3 complex or VLA-4 molecules with mAbs demonstrated that each of these molecules stimulated the tyrosine phosphorylation of unique sets of proteins with different kinetics, suggesting that these two receptor systems are coupled to distinct PTKs. Since tyrosine phosphorylation of cellular proteins has been shown to be a crucial biochemical event in cell growth, our findings suggest that the induction of pp105 tyrosine phosphorylation via VLA-4 may play a role in the transduction of activation signals through this molecule.

Analysis of matrix metalloproteinase (MMP-8 and MMP-2) activity in gingival crevicular fluid from children with Down's syndrome.

BACKGROUND AND OBJECTIVE: High levels of colonization by periodontopathic bacteria and a high prevalence of chronic inflammatory periodontal disease have been reported in children with Down's syndrome. Matrix metalloproteinases (MMPs) are mediators of extracellular matrix degradation and remodelling, and are deeply involved in the course of periodontal disease. To clarify the relationship between Down's syndrome and periodontitis, we investigated levels of MMP-2 and MMP-8 in gingival crevicular fluid (GCF) and detection of periodontopathic bacteria from subgingival plaque. MATERIAL AND METHODS: Samples of GCF and plaque were isolated from central incisors. Levels of MMPs were evaluated by enzyme-linked immunosorbent assay, and periodontopathic bacteria were detected by polymerase chain reaction. RESULTS: Levels of MMP-2 and MMP-8 in Down's syndrome patients were higher than those in healthy control subjects. In the Down's syndrome group, increases in these MMPs were observed in GCF from patients with an oral hygiene index score of < 2 and in GCF from sites that were negative for bleeding on probing. The detection rate of periodontopathic bacteria in Down's syndrome patients was higher than that in the control subjects. Matrix metalloproteinase-2 levels in sites harbouring Porphyromonas gingivalis or Aggregatibacter (Actinobacillus) actinomycetemcomitans were lower than in those without these microorganisms. CONCLUSION: These results suggest an increase in MMP-2 and MMP-8 in Down's syndrome patients, regardless of whether inflammation of periodontal tissue is present or not.

Prefrontal lobe growth in a patient with continuous spike-waves during slow sleep.

Epilepsy with continuous spike-waves during slow sleep (CSWS) is characterized by impairment of neuropsychological abilities, frequently associated with behavioral d isorders. These manifestations strongly correlate with frontal lobe dysfunctions. In the present case, an 11-year-old girl presented with progressive behavioral deteriorations after the appearance of electrical status epilepticus in sleep. The duration of CSWS period was 5 months. Serial measurements (at the appearance of the EEG pattern, and 6 months and 1, 2, 3 and 4 years thereafter) of frontal and prefrontal lobe volumes by 3-dimensional magnetic resonance imaging-based volumetry showed growth disturbance of prefrontal lobe volume, particularly prefrontal-to-frontal lobe volume ratio, after the appearance of the EEG pattern when compared with two frontal lobe epilepsy subjects without neuropsychological disorders and 13 control subjects. However, the ratio was restored to the growth ratio and seen to reach control levels, after improvement of the clinical manifestations of CSWS. These results suggest that children with CSWS may be prone to frontal lobe dysfunctions, and that the duration of CSWS period seems to be a significant prognostic factor. The urgent suppression of this EEG abnormality may be necessary to prevent the progression of neuropsychological impairments.

A prolonged course of Group A streptococcus-associated nephritis: a mild case of dense deposit disease (DDD)?

We herein report the case of a 12-year-old boy with dense deposit disease (DDD) evoked by streptococcal infection. He had been diagnosed to have asymptomatic hematuria syndrome at the age of 6 during school screening. At 12 years of age, he was found to have macrohematuria and overt proteinuria with hypocomplementemia 2 months after streptococcal pharyngitis. Renal biopsy showed endocapillary proliferative glomerulonephritis with double contours of the glomerular basement membrane. Hypocomplementemia and proteinuria were sustained for over 8 weeks. He was suspected to have dense deposit disease due to intramembranous deposits in the first and the second biopsies. 1 month after treatment with methylprednisolone pulse therapy, proteinuria decreased to a normal level. Microscopic hematuria disappeared 2 years later, but mild hypocomplementemia persisted for more than 7 years. Nephritis-associated plasmin receptor (NAPlr), a nephritic antigen for acute poststreptococcal glomerulonephritis, was found to be positive in the glomeruli for more than 8 weeks. DDD is suggested to be caused by dysgeneration of the alternative pathway due to C3NeF and impaired Factor H activity. A persistent deposition of NAPlr might be one of the factors which lead to complement dysgeneration. A close relationship was suggested to exist between the streptococcal infection and dense deposit disease in this case.

Hypercalcemia in childhood acute lymphoblastic leukemia: frequent implication of parathyroid hormone-related peptide and E2A-HLF from translocation 17;19.

Hypercalcemia is relatively rare but clinically important complication in childhood leukemic patients. To clarify the clinical characteristics, mechanisms of hypercalcemia, response to management for hypercalcemia, incidence of t(17;19) and final outcome of childhood acute lymphoblastic leukemia (ALL) accompanied by hypercalcemia, clinical data of 22 cases of childhood ALL accompanied by hypercalcemia (>12 mg/dl) reported in Japan from 1990 to 2005 were retrospectively analyzed. Eleven patients were 10 years and older. Twenty patients had low white blood cell count (<20 x 10(9)/l), 15 showed hemoglobin> or =8 g/dl and 14 showed platelet count > or =100 x 10(9)/l. Parathyroid hormone-related peptide (PTHrP)-mediated hypercalcemia was confirmed in 11 of the 16 patients in whom elevated-serum level or positive immunohistochemistry of PTHrP was observed. Hypercalcemia and accompanying renal insufficiency resolved quickly, particularly in patients treated with bisphosphonate. t(17;19) or add(19)(p13) was detected in five patients among 17 patients in whom karyotypic data were available, and the presence of E2A-HLF was confirmed in these five patients. All five patients with t(17;19)-ALL relapsed very early. Excluding the t(17;19)-ALL patients, the final outcome of ALL accompanied by hypercalcemia was similar to that of all childhood ALL patients, indicating that the development of hypercalcemia itself is not a poor prognostic factor.

Prolonged impairment of very late activating antigen-mediated T cell proliferation via the CD3 pathway after T cell-depleted allogeneic bone marrow transplantation.

One of the major obstacles in allogeneic bone marrow transplantation (allo-BMT) is prolonged T cell dysfunction resulting in a variety of infectious complications in the months to years after hematologic engraftment. We previously showed that immobilized extracellular matrix (ECM) proteins such as fibronectin (FN), the CS-1 domain of FN, or collagen (CO) acted synergistically with immobilized anti-CD3 to induce T cell proliferation. In addition, the comitogenic effect of ECMs could be mimicked by immobilized mAb reactive with a common beta 1 chain (CD29) of very late activating (VLA) antigens which include ECM receptors. Since the interaction of T cells with ECMs appears to play an important role in the process of T cell reconstitution following allo-BMT, we examined the expression of VLA antigens (alpha 1-alpha 6, beta 1) and their functional roles in CD3-mediated T cell proliferation at various times after T cell depleted allo-BMT. VLA beta 1 as well as VLA alpha 4, alpha 5, and alpha 6 expression was lower than normal controls during the first 3 mo after allo-BMT and auto-BMT, whereas these expressions returned to normal levels by 4 mo after allo-BMT and auto-BMT. Although alpha 1 and alpha 2 were not expressed on lymphocytes from normal controls, these antigens were expressed on lymphocytes at the detectable levels (5-15%) from patients after allo-BMT and auto-BMT. Both CD29 and CD3 were expressed at normal levels on lymphocytes from patients > 3 mo after allo-BMT, whereas T cell interaction with ECM through VLA proteins or crosslinking of VLA beta 1 expressed by T cells with anti-CD29 mAb results in poor induction of CD3-mediated T cell proliferation for a prolonged period (> 1 yr) after allo-BMT. In contrast, T cell proliferation induced by crosslinking of anti-CD2 or anti-CD26 with anti-CD3 was almost fully recovered by 1 yr post-allo-BMT. After autologous BMT, impaired VLA-mediated T cell proliferation via the CD3 pathway after auto-BMT returned to normal levels within 1 yr despite no significant difference in CD3 and CD29 expression following either allo- or auto-BMT. The adhesion of T cells from post-allo-BMT patients to FN-coated plate was normal or increased compared to that of normal controls. Moreover, the induction of the tyrosine phosphorylation of pp105 protein by the ligation of VLA molecules was not impaired in allo-BMT patients. These results suggest that there are some other defects in the process of VLA-mediated signal transduction in such patients. Our results imply that disturbance of VLA function could explain, at least in part, the persistent immunoincompetent state after allo-BMT and may be involved in susceptibility to opportunistic infections after allo-BMT.