Oral Anaerobes Research Articles

Detection of specific antibodies against fimbriae and membrane proteins from the oral anaerobe Bacteroides gingivalis in patients with periodontal diseases.

Sera from a number of patients with periodontal diseases were shown to have specific immunoglobulin G (IgG) antibodies against fimbriae and membrane proteins of Bacteroides gingivalis, a suspected pathogen, by using Western blottin analysis. The sera had a strong tendency to react with fimbriae, or exactly oligomeric structures of fimbriae with a native beta-structure rich-conformation. However, the sera did not react with fimbrilin, a constituent protein of fimbriae, which is denatured by sodium dodecyl sulfate.

The effect of crude extracts of nine African chewing sticks on oral anaerobes.

Chewing sticks are widely used in Nigeria for dental and oral hygiene. In-vitro susceptibility tests were done with crude extracts from nine popular sticks on four species of Bacteroides. Serindeia warneckei chewing stick had the greatest and most consistent inhibitory effect on the four species; extracts from bark and pulp were bactericidal at concentrations of less than or equal to 1%. Extracts of other sticks, when inhibitory, were only so at higher concentrations--in the range 2-30%. All the black-pigmented oral anaerobes were very susceptible to eight of the nine chewing-stick extracts but non-pigmented anaerobes showed variable susceptibilities.

Cephalosporins in surgery. Prophylaxis and therapy.

Prophylactic antibiotics in surgery are intended to prevent morbidity and mortality, as well as to reduce the duration and cost of hospitalisation. The indications for prophylaxis, and its effectiveness, should be evaluated with these criteria in mind. The basis for antibiotic prophylaxis in surgery is either provision of an effective concentration of antibiotic in the tissue site at the time of potential contamination, or (primarily in the case of colorectal surgery) to reduce the inoculum of potentially contaminating bacteria. Cephalosporins are the antibiotics most widely used for prophylaxis in surgery, and have clearly been shown to reduce postoperative morbidity in vaginal hysterectomy, resection of head and neck cancers, vascular grafting, total joint replacement, repair of hip fractures, and high risk gastroduodenal surgery. They are probably also useful in cardiac surgery, abdominal hysterectomy, caesarean section, and colorectal surgery. For orthopaedic, cardiac, gynaecological, and gastroduodenal procedures it is important to select an antibiotic with proven clinical activity against Gram-positive organisms. For head and neck surgery, the spectrum of activity should also include oral anaerobes and Enterobacteriaceae. For biliary surgery an antibiotic effective against both Gram-positive and Gram-negative organisms may offer at least theoretical advantages, while for appendicectomy a cephamycin represents the most appropriate choice. In colorectal procedures, activity against B. fragilis is the major consideration in selecting an antibiotic for systemic prophylaxis. When intra-abdominal sepsis occurs following surgery, a potentially wide range of bacteria may be implicated, but in practice such infections are due to a small number of species, with B. fragilis most commonly implicated. The most useful cephalosporins in this setting are those active against both aerobic Gram-negative bacteria and anaerobes, especially B. fragilis. In practice, an aminoglycoside is often administered concomitantly. Importantly, prompt surgical treatment is the cornerstone of management of abdominal sepsis, and empirical antibiotic therapy should be adjusted as needed when culture and sensitivity tests become available.

Purification and characterization of a novel type of fimbriae from the oral anaerobe Bacteroides gingivalis.

Fimbriae and their constituent protein (fimbrilin) were purified to homogeneity from the bacterial wash fluid and cell lysate fraction, respectively, of Bacteroides gingivalis 381. Fimbriae, observed by negative staining, were curly, single-stranded filaments with a diameter of ca. 5 nm. The apparent molecular weight of the fimbrilin was 43,000. Fimbriae were resistant to sodium dodecyl sulfate denaturation at 70 degrees C. Heating at 100 degrees C in sodium dodecyl sulfate was needed to completely dissociate them to monomers of fimbrilin. Different sets of antigenic determinants seemed to be exposed on the surfaces of fimbriae and sodium dodecyl sulfate-denatured fimbrilin. Purified fimbriae did not show either hemagglutinating activity or hemagglutination inhibitory activity, although it has been inferred on the basis of circumstantial evidence that fimbriae are correlated to hemagglutinating activity of the organism. Hemagglutinin activity, however, was detected in culture supernatant, and this observation suggests that fimbriae of a different type or a lectin-like protein may be acting as hemagglutinin in B. gingivalis.

Properties of oxaloacetate decarboxylase from Veillonella parvula

Oxaloacetate decarboxylase was purified to 136-fold from the oral anaerobe Veillonella parvula. The purified enzyme was substantially free of contaminating enzymes or proteins. Maximum activity of the enzyme was exhibited at pH 7.0 for both carboxylation and decarboxylation. At this pH, the Km values for oxaloacetate and Mg2+ were at 0.06 and 0.17 mM, respectively, whereas the Km values for pyruvate, CO2, and Mg2+ were 3.3, 1.74, and 1.85 mM, respectively. Hyperbolic kinetics were observed with all of the aforementioned compounds. The Keq' was 2.13 X 10(-3) mM-1 favoring the decarboxylation of oxaloacetate. In the carboxylation step, avidin, acetyl coenzyme A, biotin, and coenzyme A were not required. ADP and NADH had no effect on either the carboxylation or decarboxylation step, but ATP inhibited the carboxylation step competitively and the decarboxylation step noncompetitively. These types of inhibition fitted well with the overall lactate metabolism of the non-carbohydrate-fermenting anaerobe.

The bacterial flora of neonates with congenital abnormalities of the gastro-intestinal tract.

The development of the bacterial flora of neonates with congenital abnormalities of the gastro-intestinal tract was studied in 31 infants during the first 10 days of life. Specimens were collected from the umbilicus, mouth and gastro-intestinal tract on the pre-operative day, at operation and on post-operative days 1, 2, 3, 5, 7 and 10. Bacteria were isolated semi-quantitatively on a variety of plain and selective media and identified by conventional methods.Staphylococcus albus was the predominant species isolated from the umbilicus; it was recovered from 24 of the 31 babies. The viridans group of streptococci and Streptococcus salivarius were the commonest species isolated from the mouth; there were no differences between the babies with different abnormalities and treatment with antibiotics had no effect on the bacterial flora. Ten babies were colonized by each species on the pre-operative day, and 25 and 19 respectively by the tenth post-operative day. Anaerobic gram-positive cocci were the predominant oral anaerobes. Bacteria were not isolated from the rectal swabs of babies with tracheo-oesophageal fistula (TOF) or small bowel atresia on the pre-operative days. Post-operatively the predominant faecal isolates from babies with TOF were Str. faecalis, Escherichia coli and Clostridium perfringens. About 80% of the babies with small bowel atresia were colonized by Str. faecalis and Bacteroides vulgatus, 60% each by E. coli, Klebsiella aerogenes and Str. faecium. The five babies with necrotizing enterocolitis were colonized by Str. faecalis, E. coli, Cl. perfringens and Cl. difficile; Bacteroides spp. were not recovered from any of them. The commonest facultative species recovered from babies with large bowel obstruction were Str. faecalis and E. coli. B. vulgatus, Cl. perfringens and Bifidobacterium spp. were the commonest anaerobes and anaerobes outnumbered aerobes. No significant isolates were recovered from the wound swabs and none of the babies developed post-surgical sepsis.

The effect of hemolyzed erythrocytes in the virulence of Escherichia coli and of normal human oral flora in a mouse model.

Hemoglobin enhances the virulence of E. coli in the peritoneum. This study investigates the effect of blood on the virulence of E. coli and human oral anaerobes in the mouse neck. E. coli neck infectivity is significantly enhanced by blood. Oral anaerobic infections are not affected.

Gas Liquid Chromatography: From Taxonomy to Diagnosis

Gas Liquid Chromatography: From Taxonomy to Diagnosis

The importance of oral hygiene among the Aztecs and the treatment of halitosis: Samuel FastlichtQuintessence International1: 55–61, January, 1976

Piper betle L. (Piperaceae) leaves which are traditionally used in India and China in the prevention of oral malodor was examined by bioassay-guided fractionation to yield allylpyrocatechol (APC) as the major active principle which showed promising activity against obligate oral anaerobes responsible for halitosis. The biological studies with APC indicated that the potential to reduce methylmercaptan and hydrogen sulfide was mainly due to the anti-microbial activity as established using dynamic in vitro models.

Bacterial interference by oropharynegeal and clinical isolates of anaerobic bacteria.

Anaerobic isolates were tested for bacterial inhibitory activity. Of 144 isolates, 102 were from oropharynegeal washings, and 42 were from clinical specimens. Thirteen facultative bacterial species (seven members of the Enterobacteriaceae and six species of gram-positive cocci) were used as indicators of inhibition. Eleven anaerobic species were isolated from oral secretions. All isolates of Bacteroides melaninogenicus, the most commonly recovered species, consistently inhibited several species of indicator bacteria. Bacteroides fragilis, Bacteroides oralis, and Peptostreptococcus anaerobius had unprecictable inhibitory activity, whereas most of the other oral anaerobes were noninhibitory. The 42 clinical species were generally noninhibitory.