Lancefield Whole Blood Killing Assay to Evaluate Vaccine Efficacy

While the Lancefield whole blood killing assay is named after the renowned streptococcal researcher Rebecca Lancefield, the protocol was first described by Todd in 1927 (Br J Exp Pathol 8:1-5, 1927). Initially, the assay was used to identify novel Group A Streptococcal (GAS) serotypes through the supplementation of non-immune human blood (often from infants) with type-specific antisera prepared in rabbits (Lancefield, J Exp Med 106:525-544, 1957; Maxted, Br J Exp Pathol 37:415-422, 1956) and to demonstrate the impressive longevity of type-specific immunity in patients following invasive GAS infection (Lancefield, J Exp Med 110:271-292, 1959). The modern assay is routinely used to screen defined GAS mutants (Wessels, Bronze, Proc Natl Acad Sci U S A 91:12238-12242, 1994; Zinkernagel et al., Cell Host Microbe 4:170-178, 2008) or transposon libraries (Le Breton et al., Infect Immun 81:862-875, 2013) for enhanced susceptibility to opsonophagocytic killing or to screen vaccine antisera (Salehi et al., mSphere 3:e00617-e00618, 2018) or other serological preparations (Reglinski et al., Sci Rep 5:15825, 2015) for anti-streptococcal activity.</p

Inference of Antibiotic Resistance and Virulence among Diverse Group A Streptococcus Strains Using emm Sequencing and Multilocus Genotyping Methods

typing (direct sequencing of the genomic segment coding for the antigenic portion of the M protein) or by multilocus genotyping methods. Phenotype analysis, including critical AbR typing, is generally achieved by much slower and more laborious direct culture-based methods. type and the associated AbR and virulence phenotypes. types

Beneficial use of immunoglobulins in the treatment of Sydenham chorea

This double case report indicates that treatment with intravenous immunoglobulins (IVIG) is effective in patients with Sydenham chorea (SC). SC is a rare but impressive clinical manifestation following streptococcal infection. This movement disorder characterised by chorea, emotional lability and muscle weakness, is one of the major criteria of acute rheumatic fever. Treatment of SC is typically limited to supportive care and palliative medications. Curative treatment is still in the experimental stage. Recent research on patients with SC proved that antibodies against the group A streptococcus cross-react with epitopes of neurons in the basal ganglia, namely, intracellular tubulin and extracellular lysoganglioside. Therefore, immune modulating therapy by means of prednisone, plasma exchange and IVIG are mentioned in the literature as possible effective treatment. Beneficial effect of IVIG has been shown in several diseases with molecular mimicry as the underlying pathophysiology. In this paper, we describe two girls aged 11 and 13 years, respectively, who presented with SC having severe disabilities in their daily live. We treated both patients with IVIG 400 mg/kg/day for 5 days. Treatment was tolerated well and had a pronounced positive effect. Shortly after the drug was administered, all signs and symptoms disappeared in both patients. Based upon these patients, we highlight IVIG as a serious treatment option for SC

The First Human Epitope Map of the Alphaviral E1 and E2 Proteins Reveals a New E2 Epitope with Significant Virus Neutralizing Activity

Although the murine immune response to Venezuelan equine encephalitis virus (VEEV) is well-characterized, little is known about the human antibody response to VEEV. In this study we used phage display technology to isolate a panel of 11 VEEV-specfic Fabs from two human donors. Seven E2-specific and four E1-specific Fabs were identified and mapped to five E2 epitopes and three E1 epitopes. Two neutralizing Fabs were isolated, E2-specific F5 and E1-specific L1A7, although the neutralizing capacity of L1A7 was 300-fold lower than F5. F5 Fab was expressed as a complete IgG1 molecule, F5 native (n) IgG. Neutralization-escape VEEV variants for F5 nIgG were isolated and their structural genes were sequenced to determine the theoretical binding site of F5. Based on this sequence analysis as well as the ability of F5 to neutralize four neutralization-escape variants of anti-VEEV murine monoclonal antibodies (mapped to E2 amino acids 182–207), a unique neutralization domain on E2 was identified and mapped to E2 amino acids 115–119

Sydenham's Chorea: A Clinical Follow-Up of 65 Patients

Sydenham's chorea, the neurological manifestation of rheumatic fever, is the most common acquired chorea of childhood. In this retrospective study, the authors aim to present the clinical and laboratory findings of 65 Sydenham's chorea patients, followed up in a clinic over less than 7 years. The mean age at the onset of the symptoms was 11.7 +/- 2.6 years (range, 6-17 years). Of the patients, 63% were female and 37% were male (male/female: 1.7/1). Chorea was generalized in 78.5% of the patients, right hemichorea in 12.3%, and left hemichorea 9.2%. There was a history of rheumatic fever in 30.8% of the patients. Echocardiographic study showed cardiac valve involvement in 70.5% of 61 patients. Brain magnetic resonance imaging, which was performed on only 18 patients, was evaluated as normal in all. Electroencephalography was also performed on only 18 patients and showed abnormal waves in 50% of them. Pimozide was mostly the first choice of drug therapy. Nevertheless, drug therapy was not needed in 18.5% of the patients. The recovery period of the first attack of the chorea was I to 6 months in 51.7% of the patients. The recurrence rate was 37.9%. In conclusion, Sydenham's chorea is still an important health problem in Turkey with respect to its morbidity