Studies On Host Parisite Relationships In Animals Infected With Brugia Pahangi

Third stage larvae of Brugia pahangi irradiated with 10, 25 and 45 krads. of Co.SO were inhibited in their development beyond the juvenile adult stage, the fourth larval stage and third larval stage respectively. The higher two doses altered the migration pattern of most of the parasites, which were confined to the subcortical sinus of the infected lymph nodes. Hale parasites were more susceptible to irradiation than were females. Repeated infections with irradiated ».pahangi did not really change the architecture of the lymphatics of the e cats. Cats were repeatedly vaccinated with irradiated n.pahangi to determine whether attenuated parasites protected against challenge infections. Cats immunized with parasites irradiated with 10 krads. resisted 60.3 - 98.5% of the homologous challenge infections; and cats immunized with parasites irradiated with 25 krads. resisted 61 - 93% of challenge infections. The resistance in the immunized animals was mounted against all the stages of the life cycle. Two cats given heterologous challenges with Brugia patei resisted 78.6% and 65.3% of the challenge inoculations. One cat which was infected with normal parasites, and challenged after it had become amicrofilaraemic, also resisted challenge. Jirds vaccinated with parasites irradiated with 45 krads. resisted challenges, whilst vaccination with non-irradiated worms and parasites irradiated with 25 krads. did not protect these animals. Antibody responses to various homologous antigens were higher In cats given repeated infections than in cats given single infections. Antibodies against microfilariae were detected only when the animals had suppressed their microfilariae. No antibodies against adult stages could be detected in animals infected with irradiated larvae. The only significant change in the white blood cell population was eosinophilia. The highest eosinophilia occurred at the time of the onset of microfilaraemia. There were no significant changes in the serum components of cats infected with B.pahangi

The effect of irradiation on the third stage larvae of Brugia pahangi

The effect of irradiation on the third stage larvae of the filarial nematode Brugia pahangi was investigated. Labelling with 33S methionine of control or irradiated L3, post-infective L3 or L4 revealed no consistent alterations in the pattern of proteins synthesized. The only significant difference observed was in 125I labelling, where the specific activity of labelling of soluble cuticular proteins was lower in irradiated than in control parasites. This difference may be related to the reduced size of irradiated parasites rather than to a specific effect of irradiation on the expression of cuticular proteins. Irradiated parasites recovered on day 14 post-infection were significantly shorter than control parasites. Irradiation also appeared to have a lethal effect on male parasites, as no recognizable males were recovered from animals given irradiated L3, nor were microfilariae ever observed in these animals. The mechanisms by which irradiation may enhance the immunogenicity of L3 of filarial nematodes are discussed

Domiciliary cockroaches found in restaurants in five zones of Kuala Lumpur federal territory, peninsular Malaysia

The following domiciliary cockroaches were collected from restaurants in five zones of Kuala Lumpur Federal Territory, Malaysia using IL glass beaker traps baited with ground mouse-pellets: Periplaneta americana (Linnaeus) (n = 820), Periplaneta brunnea Burmeister (n = 46), Blattella germanica (Linnaeus) (n = 12504), Supella longipalpa (Fabricius) (n = 321), Symploce pallens Stephens (n = 29) and Neostylopyga rhombifolia (Stoll) (n = 5). The following bacteria were isolated from 10 cockroach specimens: Enterobacter cloacae, Klebsiella pneumoniae ssp. pneumoniae, Klebsiella pneumoniae ssp. rhinoscleromatis and Serratia liquefaciens from 5 B. germanica; Acinetobacter calcoaceticus var. anitratus, Citrobacter diversus/amalonaticus, Escherichia vulneris and K.p. pneumoniae from 3 P brunnea; and Citrobacter freundii, Enterobacter agglomerans 4, Escherichia adecarboxylate, E. vulneris, K. p. pneumonia, K p. rhinoscleromatis and Proteus vulgeris from 2 P americana

ORIGINAL ARTICLE Hookworm Infection and Reinfection Following Treatment Among

Hookworm infection is widely distributed throughout the tropics and subtropics, where almost a billion people are infected1. Prevalence of hookworm infection in Malaysia varies according to areas or communitie

The analysis of the humoral response of the BALB/c mouse immunized with radiation attenuated third stage larvae of Brugia pahangi

BALB/c mice immunized with L3 of Brugia pahangi, irradiated at 45kRad from a 137Caesium source, are strongly immune to challenge infection (75–100% reduction in the recovery of challenge infection larvae on day 6 post-challenge). The target of immunity appears to be the post-infective L3, as challenge infection larvae are killed within 5–6 days of infection. By immunoblot analysis, serum from immune animals recognizes a limited set of somatic antigens, the majority of which are shared between different life cycle stages. Serum from immune mice also strongly recognizes larval surface antigens by immunofluorescence, some of which may be stage specific. The larval surface determinants do not appear to be protein or glycoprotein by standard immunochemical analysis. A proportion of the antibody response of the BALB/c mouse is directed towards phosphorylcholine epitopes on filarial antigens, but the limited antigen recognition cannot be explained on the basis of the mouse strain used, as CBA/Ca mice recognize a similar limited set of antigens