The role of different K antigens of Escherichia coli in phagocytosis by polymorphonuclear leukocytes

Abstract

SUMMARY. The importance of K antigens from six strains of Escherichia coli for the interaction with polymorphonuclear leukocytes (PMNL) was studied. The major factor influencing this interaction was the ability of strains to activate complement by the classical route during opsonisation, this process being reduced for most K-positive strains. Interference of K antigens with the functioning of common pili as adhesins of eukaryotic cells was not observed nor a toxic effect of K antigens on PMNL.

Procession to Pediatric Bacteremia and Sepsis: Covert Operations and Failures in Diplomacy

“…30 Capsules, such as the K1 capsule of neonatal meningitis isolates of E. coli , exclude complement from the bacterial surface. 31, 32 Some of these mechanisms are not exclusive to colonization, but are also instituted by invading bacteria at later steps of BSI and can be important for the pathogenesis of sepsis.…”

Biosynthesis of Klebsiella K2 capsular polysaccharide in Escherichia coli HB101 requires the functions of rmpA and the chromosomal cps gene cluster of the virulent strain Klebsiella pneumoniae Chedid (O1:K2)

“…Capsular polysaccharide (K antigen) is one of the major surface polysaccharides (30), including acidic saccharides such as uronic acids (16). Capsular polysaccharides on the surface of bacterial outer membranes have been thought to act as a barrier against antibacterial immunoreactions of the host, such as phagocytosis by polymorphonuclear leukocytes (45) and the action of complement (14). It has been reported that Kl capsular polysaccharide of Escherichia coli is relevant to virulence (6,17).…”

The role of K antigens as virulence factors in Klebsiella

“…Association between pathogenicity and capsule size has been studied in several other bacterial species, e.g., Escherichia coli (Glynn et d., 1971;McCabe et al, 1975;Verweij-van Vught et al, 1983), pneumococcus (MacLeod and Krauss, 1950) and Staphylococcus aureus (Melly et al, 1974). One mechanism whereby the increased virulence of encapsulated bacteria might be explained is the ability of the capsule or K antigen to prevent the killing of bacteria by serum and their phagocytosis by polymorphonuclear leukocytes (PMNL) as has been shown in particular for E. coli (Howard and Glynn, 1971;Rottini et al, 1975;Van Dijk et al, 1979;Verweij-van Vught et al, 1984). Although the Received 10 May 1985;accepted 25 Jun.…”