Prospecting for new group A streptococcal vaccine candidates

Background & objectives: Most group A streptococcal (GAS) vaccine strategies focused on the surface M protein of the GAS. However, vaccine based on M protein have some drawbacks. In the present study, we used two approaches to identify new proteins and peptides that may have utility as vaccine candidates. Methods: A whole gel elution procedure was used to separate GAS surface antigens into 9 size fractionated pools. Mice were vaccinated with each pool and antibody titre, opsonic ability and protective capacity measured. In an alternative approach BioInformatics was used to identify putative GAS surface proteins. Peptides from within these proteins were then selected on the basis of predicted antigenicity or location. These peptides were conjugated to keyhole lymphocyanin (KLH) and immunogenicity measured in a mouse model. Results: One pool of GAS surface proteins (approximately 29kDa) induced antibodies that were both opsonic and potentially protective. Immunoflourescent microscopy demonstrated that these antibodies bound to the surface of M1 GAS. Amino acid sequencing subsequently identified superoxide dismutase as the major antigen in this pool. A BioInformatic search of the M1 GAS genome and subsequent analysis identified several peptides that fulfilled criteria as potential vaccine candidates. Each peptide when conjugated to KLH was able to induce a strong antibody response. Interpretation & conclusion: Several new antigens were identified that may have potential as vaccine targets. A future GAS vaccine may have multiple peptide epitopes, providing protection against multiple GAS strains

Post-traumatic endophthalmitis due to Brevibacterium casei : A case report

Endophthalmitis is a serious post-traumatic ocular complication that can lead to loss of vision. We report a case of acute post-traumatic endophthalmitis following a penetrating injury caused by an unusual organism, Brevibacterium casei . The patient was successfully treated with intravitreal antibiotics like ceftazidime and vancomycin, along with topical cefazolin and tobramycin. Brevibacterium casei can be added to the list of rare bacteria causing endophthalmitis and should be kept in mind by clinicians as a potential source of pathology

Expression of two novel proteins in Chlamydia trachomatis during natural infection

Genes for a putative membrane associated protein (mvi-homologue) and a 48 kDa protein (ctr48) in Chlamydia trachomatis were characterized. The mvi-homologue has 12 transmembrane domains and shows considerable homology to the members of this gene family in various organisms. The ctr48 has a leader sequence and the C-proximal half is tryptophan-rich. The latter region shares 65% identity with the N-proxima third of C. pneumoniae 76 kDa protein over an overlap of 231 amino acid residues. The genes for the mvi-homologue and the ctr48 are present in the B, Ba, D, E, J and L2 serotypes of C. trachomatis. Immediately downstream from the ctr48 gene are multiple stop codons which are followed by a functional rho-independent terminator. The mvi-homologue and ctr48 genes are independently transcribed, albeit poorly in serotype B. However, protein products corresponding to these genes could not be detected by western blotting in HEp2 cells infected with C. trachomatis. Nevertheless, antibodies to peptides corresponding to these proteins were detected in sera with high micro-immunofluorescence titre against C. trachomatic, collected from a Chlamydia-endemic population. These results suggest that the mvi-homologue and ctr48 are expressed by C. trachomatis during natural infection. (C) 2000 Academic Press

Firecracker eye injuries during Deepavali festival: A case series

We report a large series of ocular injuries caused by fire-crackers. This study was a hospital-based, singlecenter, retrospective case series in which the records of 51 patients with ocular injuries were analyzed. Injuries were classified according to Birmingham eye trauma terminology system (BETTS). Visual outcomes before and after the intervention were recorded. Ten patients were admitted for further management. As ocular firecracker injuries result in significant morbidity, public education regarding proper use of firecrackers may help in reducing the incidence of ocular injuries