Occlusive retinal vasculitis in an immunocompetent woman: rare presentation of ocular melioidosis

Burkholderia pseudomallei is a known great mimicker responsible for melioidosis. Ocular involvement in melioidosis is unusual, with eyelid and orbital infection as the commonest presentation. We describe a 41-year-old, healthy woman who complained of reduced vision in her left eye. On examination, vision in the left eye was 6/9. There was evidence of occlusive retinal vasculitis on fundoscopy examination. Fundus fluorescein angiogram showed extensive capillary fallout. Diagnosis was established by a rise in the serum antibody titre for the bacterium and further supported by clinical improvement of vision after completion of treatment antibiotics. Sectoral panretinal photocoagulation at the capillary fallout area successfully arrested the sequelae of retinal ischaemia. Occlusive retinal vasculitis is a rare presentation of melioidosis. Early prompt diagnosis in an immunocompetent individual helps prevent visual-related morbidity. The ability of this bacteria to cause recurrent infection in an endemic area should not be underestimated.

Peste des Petits Ruminants (PPR) virus antibodies in goats and cattle of the Saint Martin’s Island in Bangladesh

Peste des petits ruminants (PPR) is a highly contagious acute viral disease of domestic and wild ruminants particularly goats and sheep, which causes severe economic losses. Since 1993 PPR has been endemic in goats in Bangladesh. The present study was a seroprevalence study of PPR antibodies in goats and cattle at St. Martin's Island in Bangladesh from July 2012 to June 2013. There was no previous history of Rinderpest or PPR outbreak, and no Rinderpest vaccination. Blood samples were collected from 192 goats and 132 cattle randomly. All animals were apparently healthy, and were not vaccinated against Rinderpest or PPR. Serum antibody titre (competition percentage; CP value) was determined by a commercially available c-ELISA kit. The overall seroprevalence of PPR in goats was 37.5%. No serum samples from cattle were positive. In view of the high risk of PPR, a control strategy is proposed.Bangl. vet. 2014. Vol. 31, No. 2, 55-59

Immunotoxic Effects of MPT-IP Containing 60% Methylparathion in Mice

The effects of a single large and repeated small doses of MPT-IP (the industrial product used to produce Wofatox EC 50) containing 60% methylparathion, on the humoral and cellular immunoreactivity of CFLP mice were investigated. Administration of a single LD50/2 dose 3 d prior to immunization caused a 40% increase in the number of splenic PFC on the 5th day but no significant increase in serum antibody titre on the 7th day after immunization. Treatment for 4 weeks with an LD50/40 dose resulted in a 100% increase in splenic PFC, also not associated with a change in serum antibody titre. Under the same conditions and LD50/20 dose had no effect on these parameters. Neither the single large nor the repeated small doses had any effect on the intensity or time course of a DTH reaction. The results show that MPT-IP has an immunotoxic potential in mice under certain experimental conditions.

A graded-dose study of inactivated, surface antigen influenza B vaccine in volunteers: reactogenicity, antibody response and protection to challenge virus infection

SUMMARYOne hundred and nineteen volunteers were divided into five groups, and each volunteer inoculated subcutaneously with an aqueous subunit B/Hong Kong/73 vaccine containing 40, 20, 10, or 5 μg of HA or saline alone in a 0·5 ml volume. The incidence of reactions was recorded 24 h after inoculation. One month following immunization the serum HI antibody to B/Hong Kong/73 virus was measured; each volunteer was inoculated intranasally with live, attenuated influenza B (RB77) virus; and the incidence of infection by the challenge virus was determined by HI antibody response.The results showed that the incidence of reactions to all doses of vaccine were relatively low, the severity mild, and the duration short. However, the incidence of reactions was highest for those given 40 μg HA and least for those given 5 μg HA. The serum HI antibody responses to vaccine showed a dose-response relationship. For volunteers given 40 μg HA, 22 (96%) showed a fourfold rise in antibody titre and all volunteers had antibody titres of > 40 following immunization: for volunteers given 5 μg HA the g.m.t. increased from 16·6 to 86·1; and for those given 10 and 20 μg HA the response was intermediate. Following challenge, the lowest incidence of infection was seen in volunteers given the highest dose of vaccine. However, all doses of vaccine induced some protection against challenge virus infection, and the incidence of infection was directly related to the serum antibody titre at the time of challenge. The 50% protection titre of serum HI antibody was estimated as 15 to 20.

The Development Of Monoclonal Antibodies To Factor VIII Related Antigen (VIIIRAG)

A human VIIIRAg rich fraction was prepared from human factor VIII concentrate by gel chromatography on Sepharose CL6B to give 40 u/ml VIIIRAg and 0.06 u/ml factor VIII clotting antigen (VIIICAg). Balb/c mice were immunised with this fraction (1-2 u VIIIRAg per mouse) and polyclonal antibody to VIIIRAg was detected in the serum of the mice by conventional immunodiffusion and by a specially developed immunoradlometric test (IRMT). This test utilised polystyrene tubes coated with polyclonal (sheep) antibody to VIIIRAg which were then incubated with a source of human VIIIRAg (pooled normal plasma). After incubation with mouse anti human VIIIRAg the bound mouse immunoglobulin was detected by binding of 125I labelled rabbit anti mouse IgG. This was prepared from commercial rabbit anti mouse IgG by immunoadsorption and elution from immobilised mouse immunoglobulin. Using the IRMT a monoclonal antibody to VIIIRAg was detectable at a dilution of 5 × 105. Mice with the highest serum antibody titre were selected, hyper- immunised and used as spleen donors. Spleen cells were harvested, fused with homologous NS-1 myeloma cells and cultured in HAT selective medium. Hybrids producing specific antibody to VIIIRAg were detected by the IRMT and cloned by the limiting dilution method. Antibodies were tested for their activity against VIIIRAg and factor VIII related ristocetin cofactor activity, and also for any activity against VIIICAg and procoagulant factor VIII.

Studies on Tyzzer's Disease: Acquired Immunity Against Infection and Activation of Infection by Immunosuppressive Treatment

Summary The correlation between serum antibody titre and resistance to challenge infection with Bacillus piliformis was studied in naturally infected mice, in experimentally infected but recovered mice, and in mice treated with antigen prepared from infected livers. Irrespective of the way in which the antibodies were acquired resistance to infection was found to be related to the immunofluorescence antibody titre found. Experimentally infected but recovered mice, as well as rats with persistent antibodies to Bacillus piliformis, were given prednisolone in order to activate a possible persistent infection. Bacillus piliformis was detected in the rats, but not in the mice.

Variation in the absorption of a colostrally secreted marker antibody in piglets

1. Sixteen sows were immunised in late pregnancy with Salmonella pullorum antigen. Sows showed marked differences in serum antibody titre at parturition.2. Twelve hours after birth, serum antibody titres in the 173 piglets born to the 16 sows were measured. They were positively related to the serum titres of their mother.3. Marked variation existed in the antibody titres of colostra from different teats and from different sows. No relationship was found between colostral titres and the titres in sow or piglet sera.4. Sow and piglet serum titres were negatively related to piglet and litter weight gain from birth to 7 days of age.5. Those piglets with high serum antibody titres at 12 hr. after birth displayed better growth rates and enjoyed lower mortality than piglets with low antibody titres.