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W A Nichols

Publications and source records attributed to W A Nichols.

12 recordsLinked to original sources
PubMed1990

Characterization of the type 1 fimbrial subunit gene (fimA) of Serratia marcescens.

The nucleotide sequence of a DNA fragment that contains the fimA gene, encoding the major fimbrial subunit, of Serratia marcescens IA506 and associated flanking sequences has been elucidated. In addition, the origin of transcription has been identified and is located 120 base pairs upstream of the fimA initiation codon. The predicted amino acid sequence of the FimA polypeptide exhibits some degree of sequence homology with the fimbrial subunits encoded by the fimA determinants of Klebsiella pneumoniae, Salmonella typhimurium, and Escherichia coli and also to Smf2, the major structural component of mannose-resistant (MR) fimbriae of S. marcescens. The Serratia adhesin that facilitates haemagglutination mediated by type 1 fimbriae is less susceptible to inhibition by D-mannose than has been observed to be the case in other type 1 fimbrial adhesins. The molecule conferring this adherence specificity has been shown to be distinct from the fimA gene product and, therefore, is analogous to the fimbrial systems reported in other species.

Amino Acid Sequence↗
PubMed1989

Expression of type 1 fimbriae and mannose-sensitive hemagglutinin by recombinant plasmids.

Deletions within the cloned genes (fimA) encoding the type 1 major fimbrial subunits of two isolates of Klebsiella pneumoniae resulted in a nonfimbriate but hemagglutinating phenotype after transformation of Escherichia coli HB101 or ORN103. Phenotypic expression of type 1 fimbriae could be restored by transformation with plasmids containing the fimA genes of the fimbrial gene clusters from different strains. The surface fimbriae expressed were serologically identical to those of the polymerized product of the introduced fimA gene. The fimA gene products of Salmonella typhimurium and Serratia marcescens could utilize the accessory fimbrial genes of K. pneumoniae to produce surface-associated, hemagglutinating fimbriae. The relatedness of the type 1 fimbrial gene clusters from multiple isolates of members of the family Enterobacteriaceae was examined by DNA hybridization techniques. These analyses demonstrated little nucleotide sequence agreement among distinct genera of the enteric bacteria.

Bacterial Adhesion↗
PubMed1989

A fluoride analysis program to reduce tooth decay in rural children.

Daily ingestion of optimal amounts of fluoride has been shown to significantly reduce the incidence of tooth decay in children. Fluoridated drinking water is the most effective and efficient primary source of fluoride. Children who do not drink sufficient fluoridated water should receive supplemental fluoride in the form of drops and tablets. Fluoride supplements beginning with the newborn infant at two weeks of age should be prescribed in accordance with the dosage schedules of the American Academy of Pediatrics and the American Dental Association. Fluoride levels of the drinking water source must be determined before prescribing a fluoride supplement. The Arkansas Department of Health offers dentists and physicians a program to analyze the fluoride content of private well or spring water. The program operates through local County Health Departments. Information about the fluoride level in the drinking water of a CWS is available by contacting either that particular CWS or the Engineer Division, Arkansas Department of Health. Questions about fluoride supplementation and/or optimally fluoridated CWS's should be directed to Dr. Wharton A. Nichols, Office of Dental Health, Arkansas Department of Health, 4815 West Markham, Little Rock, AR 72205, (501) 661-2483.

Adolescent↗