An emerging zoonotic clone in the Netherlands provides clues to virulence and zoonotic potential of Streptococcus suis

Streptococcus suis is a zoonotic swine pathogen and a major public health concern in Asia, where it emerged as an important cause of bacterial meningitis in adults. While associated with food-borne transmission in Asia, zoonotic S. suis infections are mainly occupational hazards elsewhere. To identify genomic differences that can explain zoonotic potential, we compared whole genomes of 98 S. suis isolates from human patients and pigs with invasive disease in the Netherlands, and validated our observations with 18 complete and publicly available sequences. Zoonotic isolates have smaller genomes than non-zoonotic isolates, but contain more virulence factors. We identified a zoonotic S. suis clone that diverged from a non-zoonotic clone by means of gene loss, a capsule switch, and acquisition of a two-component signalling system in the late 19th century, when foreign pig breeds were introduced. Our results indicate that zoonotic potential of S. suis results from gene loss, recombination and horizontal gene transfer events.

Evaluation of methotrexate and corticosteroids for the treatment of localized scleroderma (morphoea) in children

BACKGROUND

Localized scleroderma (LS) or morphoea is often considered to be a benign self-limiting condition confined to the skin and subcutaneous tissue. However, the course of the disease is unpredictable and severe functional and cosmetic disability may result. Drug treatment with systemic corticosteroids in combination with methotrexate has been reported to be beneficial in LS, but data in children is limited.

OBJECTIVES

To evaluate the efficacy and tolerability of systemic corticosteroids in combination with methotrexate in children with LS.

METHODS

Treatment and outcome of 34 patients with LS were retrospectively analysed. Pulsed intravenous methylprednisolone was given, followed by oral prednisolone on a reducing regimen and maintenance treatment with methotrexate. We assessed treatment outcome clinically and by thermography and monitored adverse events.

RESULTS

From the onset of treatment, the disease stopped progressing in 94% of the patients. All patients demonstrated significant clinical improvement within a mean time of 5.7 +/- 3.9 months. Mean duration of follow-up over the treatment period and beyond was 2.9 +/- 2.0 years. In 16 (47%) patients therapy was discontinued when the disease was considered to be inactive clinically; however, seven (44%) of the 16 developed a relapse, necessitating repeat treatment. At last follow-up (range 0.2-7.0 years), 24 (71%) of the 34 patients had completely inactive disease. Observed adverse events were moderate and transient and no patient had to stop therapy.

CONCLUSIONS

These data suggest that systemic corticosteroids and methotrexate in combination are beneficial and well tolerated in the treatment of children with LS. Because of the risk of relapse after discontinuing therapy, long-term monitoring is mandatory.

Juvenile-onset localized scleroderma activity detection by infrared thermography

OBJECTIVE

The aim of this study was to define the clinical utility of infrared thermography in disease activity detection in localized scleroderma (LS).

METHODS

We retrospectively reviewed 130 thermal images of 40 children with LS and calculated the sensitivity and specificity of thermography, comparing clinical descriptions of the lesions and contemporary thermographs. The reproducibility of thermography was calculated by using the weighted kappa coefficient to determine the level of agreement between two clinicians who reviewed the thermographs independently.

RESULTS

The sensitivity of thermography was 92% and specificity was 68%. Full concordance between the two clinicians was observed in 91% of lesions, with a kappa score of 0.82, implying very high reproducibility of this technique.

CONCLUSION

Our results demonstrate that thermography is a promising diagnostic tool when associated with clinical examination in discriminating disease activity, as long as it is applied to lesions without severe atrophy of the skin and subcutaneous fat. Further evaluation is needed to determine whether thermography can predict the future progression of lesions.

Comparative efficacies of terbinafine and fluconazole in treatment of experimental coccidioidal meningitis in a rabbit model

A rabbit model of coccidioidal meningitis was used to compare the therapeutic efficacies of terbinafine (TBF) and fluconazole (FCZ). Hydrocortisone acetate-treated New Zealand White male rabbits were infected intracisternally with either 2.2 x 10(4) or 6.4 x 10(4) Coccidioides immitis arthroconidia. Oral treatment with polyethylene glycol 200 (PEG) twice daily (n = 8), TBF twice daily (n = 9; 200 mg/kg of body weight/day), or FCZ once daily (n = 8; 80 mg/kg/day) began on day 5 and continued for 21 days. Mean survival times were 20, 24, and 32 days for rabbits treated with PEG, TBF, and FCZ, respectively. All of the FCZ-treated animals (100%; P = 0.003), 56% of the TBF-treated animals (P = 0.4), and 25% of the PEG-treated animals survived the length of the study. Both FCZ and TBF were effective at reducing the incidence of paresis. Only FCZ was effective at reducing most neurological and systemic signs. FCZ treatments resulted in lower cerebrospinal fluid (CSF) protein concentrations and leukocyte counts and faster clearing of CSF fungal cultures compared with those for PEG-treated controls, but TBF treatments had no significant effect on these parameters. Neither drug affected CSF glucose levels. Mean serum TBF levels by bioassay were within the range of 3.5 to 6.2 microgram/ml at 1, 2, and 4 h postdosing and 0.35 to 7.0 microgram/ml at 14 h postdosing. No TBF was detected in CSF. Mean FCZ levels (24 to 25.5 h postdosing) by bioassay were 16.4 to 19.2 and 13.5 to 19.2 microgram/ml in serum and CSF, respectively. The reduction in the numbers of CFU in the spinal cord and brain was over 100-fold (P = 0.0005) in FCZ-treated animals and 2-fold (P </= 0.2) in TBF-treated animals compared with those in PEG-treated animals. Histopathologic severity (semiquantitative scoring system) was significantly attenuated by FCZ treatment (P = 0. 05) and was slightly attenuated by TBF treatment compared with that for the controls. In conclusion, TBF appeared to have a slight effect on survival, histology, and reduction of the numbers of CFU in tissue; however, these effects were not significant. FCZ was effective at controlling coccidioidal meningitis.

Increased proliferation, collagen, and fibronectin production by hereditary gingival fibromatosis fibroblasts

HEREDITARY GINGIVAL FIBROMATOSIS (HGF) is a fibrotic enlargement of the gingiva. HGF gingiva contains large amounts of interstitial collagen and other extracellular matrix (ECM) molecules. Increased proliferation and elevated production of the ECM molecules type I collagen and fibronectin (FN) could contribute to the clinical increased bulk of HGF gingiva. Fibroblast strains from HGF gingiva and normal human gingival fibroblast strains (GN) were used in this in vitro study. Fibroblast proliferation was determined by ELISA which measured the incorporation of 5-bromo-2'-deoxyuridine into DNA. The results showed that HGF fibroblast strains proliferated more rapidly than GN fibroblasts (68% to 488% increase, depending on the strains) (P < or = 0.01), the only exception being one HGF strain versus one normal strain. All HGF strains produced greater amounts of FN (measured by ELISA) than all of the normal fibroblast strains (23% to 49% increase, depending on the strain) (P < or = 0.04). Similarly, all HGF strains made significantly greater (P < or = 0.3) amounts of type I collagen (also measured by ELISA) than all of the normal strains (55% to 235% increase, depending on the strain). The results show that, in vitro, HGF fibroblasts display several phenotypic characteristics of activated fibroblasts: increased proliferative rates as well as increased production of FN and type I collagen, consistent with in vitro studies of fibroblasts derived from other types of fibrotic tissue. These results suggest that the increased proliferation of HGF fibroblasts and their increased production of extracellular matrix molecules such as collagen and FN may contribute to the clinical gingival enlargement characteristics of HGF.