Human milk inhibited the attachment of Streptococcus pneumoniae and Haemophilus influenzae to human pharyngeal or buccal epithelial cells. Infant formulas and cow and buffalo milk showed a lower inhibitory activity against pneumococci and enhanced the adhesion of H. influenzae. The antiadhesive effect against S. pneumoniae was found in both the high- and the low-molecular-weight fractions of milk. The inhibitory activity in the high-molecular-weight fraction was independent of specific antibody content; it was present after immunoadsorption and in the milk from IgA-deficient women. The inhibitory activity in the low-molecular-weight fraction was in part explained by the content of oligosaccharides corresponding to the carbohydrate moieties of the neolactoseries of glycolipids, which have previously been shown to act as receptors for attaching pneumococci. The antiadhesive activity against H. influenzae was restricted to the high-molecular-weight fraction of the milk and was unaffected by immunoadsorption. Milk may protect against otitis by reducing colonization.

No abstract

Glycolipids of the lactoseries act as blood group A, B, and H and Lewis antigens (11), and the blood group P and pk (30, 49) and Forssman (11) antigens are found in the globoseries.

A chromosomal DNA fragment which mediates Pap (pili associated with pyelonephritis) pili formation, mannose‐resistant hemagglutination (MRHA) and binding to uroepithelial cells has been isolated from the uropathogenic Escherichia coli clinical isolate J96, and genetically studied. Analysis of polypeptides expressed by the Pap DNA led to detection of a number of polypeptides ranging in mol. wt. from 13 000 to 81 000 daltons. The gene order and transcriptional orientation for four of the corresponding cistrons was: 13 000 (papB) 19 500 (papA, structural gene for the Pap pilus subunit), 81 000 (papC) and 28 500 (papD). Analyses of a lacZ‐ papA gene fusion located a promoter upstream from papA within the cloned DNA. Transposon Tn5 insertions in any of these four cistrons decreased or eliminated Pap pili formation. A number of transposon Tn5 mutations were identified in a region distal to papD that expressed normal levels of the papA protein on the cell surface in the form of recognizable pili structures but did not agglutinate human erythrocytes or adhere to uroepithelial cells. This region expressed polypeptides of 15 000, 24 000, 26 000 and 35 000 daltons. This finding shows that Pap pili formation and binding properties can be genetically dissociated.

The genetic organization and epidemiology of Dr hemagglutinin was studied. Plasmids derived from pBJN406 and carrying transposon inserts were analyzed for their abilities to confer the mannose-resistant hemagglutination phenotype and expression of plasmid-encoded proteins. The 6.6-kilobase DNA fragment expressed five polypeptides with molecular masses of 15.5, 5, 18, 90, and 32 kilodaltons encoded by the draA, draB, draC, draD, and draE genes, respectively. Four genes, draA, draC, draD, and draE, were required for full mannose-resistant hemagglutination expression. Mutation in the draA gene, previously identified as encoding fimbrillin, resulted in loss of the adherence phenotype. We screened 658 strains isolated from patients with urinary tract infections (UTI) or from fecal samples for the presence of DNA sequences homologous to the draD gene. A significantly higher frequency of draD-related sequences was found among Escherichia coli strains from patients with cystitis than among strains from patients with other clinical forms of UTI. Association of draD-related sequences with O75 and other serotypes was observed. A possible role of Dr hemagglutinin as a virulence factor in lower UTI is discussed.