Haemagglutination assay of some human and animal arcobacter specie

Abstract

Arcobacter are emerging food borne enteropathogens which can cause severe diarrhea and occasional systemic infection such as bacteraemia and peritonitis in humans. To understand the pathogenicity of this emerging pathogen, putative adhesive factors in the organism were studied by examining their ability to agglutinate erythrocytes from humans and other animal species. A total of 10 Arcobacter species from which four strains were obtained from humans and one from pigs in France. Five isolates were obtained from stool of healthy pigs and chicken in Nigeria. They were identified and confirmed by phenotypic and PCR techniques. Bacteria cells were washed in PBS by centrifugation. 20 μl of bacteria cells was reacted with equal volume of erythrocytes. Macroscopic haemagglutination was scored as either positive or negative after 5 minutes of mixing at room temperature. To understand the nature of red cell receptor for haemagglutinin, various sugars was used to inhibit previously positive haemagglutination reaction. Fresh cultures of all strains agglutinated erythrocytes from humans (blood group A+), sheep, guinea-pig and chicken. 20μl of all suspension containing 10 cells\ml gave a strong microscopic haemagglutination within 5 minutes after mixing with an equal volume of 3% erythrocytes suspension on a clean microscopic slide. No inhibition was observed with D glucose and mannose on previously positive haemagglutinating strains, but galactose inhibited by the same 50/50% (v|v). The result of this experiment provides a basis for further development of specific immunogen required for a more detailed study of characterization of specific adhesins.

Keywords: Arcobacter, Haemagglutination, Adhesive factors, Nigeria