Biomedical subjects

G E Minah

Publications and source records attributed to G E Minah.

At least 19 recordsLinked to original sources

PubMed2006

Evaluation of microbiological screening systems using dental plaque specimens from young children aged 6-36 months.

Using cotton swab specimens of dental plaque from children aged 6-36 months, four commercial chairside tests for oral bacteria were evaluated by comparison with conventional selective culture: mitis salivarius kanamycin bacitracin agar for mutans streptococci and Rogosa SL agar for lactobacilli. Representative colonies of all isolates were identified by commercial identification kits. According to qualitative evaluations, all chairside tests for mutans streptococci were effective in our population. Those for lactobacilli were not as effective, due mainly to a high recovery of yeast contaminants.

Bacterial Typing Techniques↗

PubMed2000

Candida albicans colonization of surface-sealed interim soft liners.

PURPOSE: This in-vivo investigation evaluated the effect of 2 denture sealer agents on the microbial colonization of a newly placed soft interim denture liner during a period of 14 days. MATERIALS AND METHODS: An interim soft denture liner (Coe-Soft; GC America, Alsip, IL) was coated with 2 different denture surface sealants (Palaseal [Heraeus Kulzer, Irvine, CA] and Mono-Poly [Plastodent, New York, NY]). Three rectangular wells of 1 cm wide x 2 cm long x 2 mm deep were placed in the intaglio of 10 maxillary complete dentures and filled with the soft liner material. The soft liner surface was treated with Palaseal (first well) and Mono-Poly (second well), and the unsealed (third well) was used as a control. These were exposed to the oral cavity for 14 days. The effect the sealant had in the prevention of Candidal colonization in vivo of the soft liner material was evaluated. Microbiological specimens were recovered from all samples and cultivated. Microbiological data from the control and 2-test samples in each denture were tabulated, and statistical analyses were performed. RESULTS: This investigation showed clear differences (p <.001) between the sealed and unsealed soft liners. The sealed material showed significantly less colonization by yeast and bacteria. Intercomparison of the surface denture sealers, Palaseal versus Mono-Poly, showed no statistically significant differences (p < .005) in total yeast or bacterial colonization. CONCLUSION: Coating of Coe-Soft denture liner with either Palaseal or Mono-Poly significantly decreased yeast and bacterial colonization. .

Adult↗

PubMed1996

Development and evaluation of a selective and differential medium for the primary isolation of Peptostreptococcus micros.

Peptostreptococcus micros, an anaerobic gram-positive coccus, has been associated with periodontal and endodontic lesions, including those refractory to treatment, as well as many human polymicrobial infections in other body locations. A selective and differential medium for the primary isolation of P. micros was developed and evaluated. Columbia CNA agar, a selective medium for gram-positive cocci, was supplemented with glutathione and lead acetate (P. micros medium: PMM). P. micros has a characteristic of rapidly utilizing the reduced form of glutathione to form hydrogen sulfide, which reacts with lead acetate producing a black precipitate in the medium. When grown on PMM, P. micros can be easily identified by its typical colonial morphology and the presence of a black precipitate directly under the colony. PMM was compared for the growth of P. micros with phenylethyl alcohol agar (PEA) and Columbia base medium (CBM) with 80 strains of P. micros and 30 strains of other gram-positive cocci. All P. micros isolates tested grew and showed the typical morphology of P. micros on PMM. Using colony counts on CBM as controls, there was an average 81.8% recovery in the number of P. micros colonies on PMM, in contrast to an average 6.1% recovery on PEA. Subgingival plaque and tongue samples from 12 adult periodontitis and 6 early-onset periodontitis patients were cultured onto PMM for the isolation of P. micros. P. micros was isolated on PMM and identified biochemically and enzymatically from both adult periodontitis and early-onset periodontitis patients with higher percentages isolated from the diseased periodontal pockets of adult periodontitis patients; furthermore, this is the first isolation of P. micros from tongue samples taken from periodontally diseased patients. This medium in cultural studies will further our understanding and assist future investigations of P. micros involved in disease processes.

Agar↗

PubMed1996

Effect of an antiseptic mouthrinse on salivary microbiota.

PURPOSE: To evaluate the effect of rinsing with original formulation Listerine Antiseptic (LA) on the level of viable salivary bacteria for periods up to 1 hour. MATERIALS AND METHODS: In this double-blind, controlled, cross-over study, unstimulated saliva was collected from 25 subjects, serially diluted, and cultured on selective and non-selective media under aerobic and anaerobic conditions. Streptococci, Veillonella sp., and total aerobic and anaerobic flora were enumerated just prior to and 2, 15, 30, and 60 minutes after rinsing for 30 seconds with either 20 ml of LA or a 5% hydroalcohol control rinse. RESULTS: After the control rinse, total flora cultivated on MM10 agar exhibited a non-significant (P > 0.05) 10%-20% decrease relative to baseline. In contrast, rinsing with LA resulted in a significant (P < 0.05) 60%-65% decrease from baseline in all four microbial groups at 2 minutes; except in the case of Veillonella, the significant decreases were sustained up to 60 minutes. Total Listerine group aerobic, anaerobic and streptococcal counts were significantly lower than placebo (P < 0.05). The significant reduction in salivary bacterial levels seen in the Listerine group for up to 60 minutes suggests that this antiseptic mouthrinse may have use clinically as a pre-procedural rinse to decrease the level of viable microorganisms in aerosols generated during dental procedures.

Adult↗

PubMed1994

Use of the Syrian golden hamster for the induction of intraoral abscesses by sutures contaminated with human subgingival plaque.

Analysis of normal oral flora in 150 cheek pouches of hamsters (Mesocricetus auratus) defined the microbial working environment and demonstrated the absence of human oral black-pigmented bacteria. Silk sutures saturated with Porphyromonas gingivalis, Prevotella intermedia or subgingival plaque were used to close wounds made in hamster's cheek pouches. Abscesses were formed when sutures had solitary P. gingivalis or other bacteria mixed with P. gingivalis or when P. intermedia was mixed with other bacteria besides P. gingivalis. A concentration of black-pigmented bacteria emanating from 3 x 10(5) colony-forming units/inoculum was required for abscess formation. Six abscesses (14.3%) were developed in association with the presence of other odontopathic bacteria, primarily Fusobacterium nucleatum and Actinomyces viscosus. The hamster cheek pouch with iatrogenic wounds closed with plaque-impregnated sutures is a novel and effective model to study the pathology of wound infections and virulence of human subgingival organisms.

Abscess↗

PubMed1993

Correlation between thermal sensitivity and microorganisms isolated from deep carious dentin.

The correlation between thermal sensitivity and the microorganisms present in 29 deep carious lesions was studied. The numbers of lactobacilli and total Gram-positive rods in the carious lesions were found to be negatively related to the length of pain triggered by cold and heat stimulants. The presence of Gram-positive cocci and non-black-pigmented Bacteroides were positively associated with both cold and heat sensitivities. Black-pigmented Bacteroides, Streptococcus mutans, and total anaerobic colony counts were positively related to the heat sensitivity. Recovery of Fusobacterium nucleatum, Actinomyces viscosus, and enterics on the selective plates was associated with cold sensitivity. Total counts of Gram-positive cocci and Gram-negative rods on the anaerobic nonselective medium were positively related to the cold sensitivity. It appeared that teeth with low numbers of lactobacilli in the carious lesions usually responded to thermal tests with longer duration of pain. Conversely, teeth with high numbers of lactobacilli in the carious lesions usually responded with shorter duration of pain.

Bacteroides↗

PubMed1992

Microbiological evaluation of periapical infections in Egypt.

This study identifies and correlates proportions of bacteria in periapically involved anterior teeth of 85 adult Egyptian patients. Affected sites were free from caries and periodontal disease but had a history of trauma. The mean number of component bacterial species per specimen was 3.1. Anaerobic bacteria were the dominant flora present in specimen cultures, comprising 73% (190/259) of cultivable bacteria. The most frequently isolated organisms were Eubacterium species (68%), black-pigmented Bacteroides (56%), Streptococcus morbillorum (47%) and non-pigmented Bacteroides (37%). These organisms also showed the highest proportional values relative to total cultivable bacteria. The mean percentages of total viable counts of these isolates were 19.0%, 14.1%, 18.0% and 15.5%, respectively. Statistical analysis of data revealed a significant negative correlation between S. morbillorum and Bacteroides species.

Adolescent↗

PubMed1992

Clinical effects of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine. Mediating influence of periodontal probing depth.

The clinical and microbial effects of a single episode of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine (CHX) were studied as a function of clinical probing depth in patients with adult periodontitis. 60 patients were randomly assigned to receive subgingival irrigation under cavitation with either sterile water or 0.12% CHX delivered through the tip of an ultrasonically activated scaler as part of initial periodontal therapy in a double-blind study design. 3 periodontal sites were randomly selected for examination from each patient on the basis of clinical probing depth, with 1 site being selected within each of the following ranges: 1-3 mm, 4-6 mm, and 7-9 mm. Pretreatment and post-treatment (days 14 and 28) clinical assessments included a plaque index (PI), gingival index (GI), and clinical probing depth (CPD). Subgingival specimens also were collected from 1-3 mm and 4-6 mm sites on a random subset of patients (15 per group). Plaque counts of spirochetes and motile organisms were made by darkfield microscopy. Significant reductions in PI, GI, and CPD were observed among all sites within both treatment groups at 14 and 28 days post-treatment. CHX irrigation resulted in a significantly greater reduction in CPD than did water among sites initially probing 4-6 mm at both 14 and 28 days post-treatment (25% versus 13% and 31% versus 18%, respectively). Spirochete counts were modestly but nonsignificantly reduced at 14 days post-treatment among sites 4-6 mm within both treatment groups. These results suggest that subgingival irrigation with CHX during ultrasonic scaling provides differential clinical benefits that are site-dependent.

Adult↗

PubMed1991

Microbiological studies of carious dentine from human teeth with irreversible pulpitis.

Aerobic and anaerobic cultures were made from 29 extracted teeth with irreversible pulpitis to identify the predominant flora in different parts of deep carious lesions. Most isolates were Gram-positive rods, in which lactobacilli were the most frequent organisms, then other Gram-positive, non-branching rods. Gram-positive cocci were the next most common; only a low number of Streptococcus mutans was recovered. Two types of carious lesions were found, one with high numbers of lactobacilli, the other with low. In the 15 lesions with high numbers, lactobacilli constituted 91.9% of the total flora at the pulpal site and gradually decreased in number as the sampling moved away from the pulp. Strep. mutans and alpha-haemolytic streptococci were not recovered from pulpal or deep carious sites in this group. In the 14 lesions with low numbers of lactobacilli, the flora was diverse. Gram-positive cocci, anaerobic Gram-positive non-branching rods, branching rods and/or Bacteroides were the main isolates in a few of this group.

Actinomyces↗

PubMed1990

Effect of granulocytopenia on oral microbial relationships in patients with acute leukemia.

Risk for acute infection increases as granulocyte levels decrease secondary to myelosuppressive chemotherapy in patients with acute nonlymphocytic leukemia (ANLL). Acute exacerbations of concomitant inflammatory periodontal diseases can result in systemic infections in these patients. However, host-oral bacterial relationships in the periodontium in patients with ANLL are not well understood. Twenty-one adult patients with ANLL with periodontal disease ranging from gingivitis to severe periodontitis were studied. Supragingival and subgingival plaque specimens were collected before chemotherapy (prechemotherapy), and at a defined midpoint of myelosuppression (midchemotherapy; day 14). All specimens were extensively cultured both aerobically and anaerobically. Data were submitted to a partial correlational analysis, controlling for covariation relation to oral hygiene intervention and antibiotic administration. Levels of total yeast exhibited a significant association with Staphylococcus sp. at supragingival sites midchemotherapy (r = 0.68, p less than or equal to 0.05). Levels of total yeast also correlated positively with Pseudomonas aeruginosa at subgingival sites both prechemotherapy (r = 0.70, p less than or equal to 0.01) and midchemotherapy (r = 0.61, p less than or equal to 0.05). Significant correlations of levels of Veillonella sp. with Neisseria sp. and gram-negative enteric bacilli were observed in both supragingival (r = 0.95, 0.77, p values less than or equal to 0.01) and subgingival (r = 0.69, 0.61, p values less than or equal to 0.05) plaque specimens midchemotherapy but not prechemotherapy. These data suggest that potentially pathogenic bacteria occur in plaque simultaneous with granulocytopenia in these patients. Multiple mechanisms, including intergeneric coaggregation and other symbiotic relationships, may influence infectivity of the mixed plaque flora and thus contribute to the oral ecology observed in these patients.

Adult↗

PubMed1990

Coaggregation of oral Candida isolates with bacteria from bone marrow transplant recipients.

In vitro coaggregation between Candida species isolated from immunosuppressed bone marrow transplant recipients and oral bacteria was investigated. Each Candida strain showed a different pattern of coaggregation with the 22 bacterial strains studied. Two strains of Lactobacillus amylovorus isolated from separate bone marrow transplant patients and Fusobacterium nucleatum (VPI 10197) coaggregated with all Candida strains. Ten bacterial strains showed no coaggregation with the Candida strains. A variety of inhibition patterns were observed when coaggregating strains were first incubated with various sugars or subjected to heat treatment. Positive and negative results were generally consistent with all Candida strains. On the basis of the culture characteristics of the oral rinse specimens, relationships between the colonization of bacteria and yeasts and in vitro coaggregation were suggested.

Bacteria↗

PubMed1990

Comparative microbiological and immunological studies of subgingival dental plaque from man and baboons.

Baboons may be useful as animal models for the study of human oral diseases and infections. They are closely related to man anatomically, physiologically, and phylogenetically. Plaque and gingival indices were relatively low in 18 baboons (Papio anubis). The mean scores ranged between 0.62 +/- 0.29 and 0.37 +/- 0.20, respectively. Gram-positive and Gram-negative cocci comprised 27.0 +/- 32.4 and 3.1 +/- 7.5% of the total viable counts in the dental plaque samples. Black-pigmented Bacteroides formed about 1.9 +/- 5.9% of the bacterial population in the samples. Anaerobic Gram-negative bacilli were found in 73.2% of the samples and averaged 19.2 +/- 26.3% of the total recovered flora. Species of the oral Actinomyces and other Gram-positive rods found in humans were not isolated. The composition of the oral flora in baboons appeared to be significantly different from that of man. Isolates of F. nucleatum, L. buccalis, and B. intermedius from the two mammals were biochemically similar, but were distinguishable by analysis with antibody, both by precipitin lines and/or differences between homologous and heterologous titers.

Animals↗

PubMed1990

Comparative effects of 2 chemotherapeutic mouthrinses on the development of supragingival dental plaque and gingivitis.

A 6-month double-blind, controlled clinical study was completed with 124 healthy adult subjects to determine the efficacy of 2 mouthrinses, Listerine (LA) and Peridex (PX), used as supplements to regular oral hygiene measures in reducing supragingival dental plaque and gingivitis. Following screening examinations for entry levels of existing gingivitis and plaque, baseline gingival and plaque area indices, extrinsic tooth stain, supragingival calculus, bleeding and soft tissue condition were recorded. All subjects then received a complete dental prophylaxis to remove plaque, calculus and extrinsic stain. Subjects were randomly assigned to 1 of 3 groups and performed supervised rinses twice daily for 30 s in addition to their normal oral hygiene, for 6 months. All indices were again evaluated at 3 and 6 months. After 6 months, LA and PX significantly (p less than 0.001) inhibited development of plaque by 36.1% and 50.3%, respectively, and the development of gingivitis by 35.9% and 30.5%, respectively, compared to a hydroalcohol control. PX was more effective in inhibiting plaque and both mouthrinses appeared to be equally effective in inhibiting gingivitis. LA patients did not develop significant levels of stain or supragingival calculus at 6 months, compared to baseline or control. PX patients developed significant levels of extrinsic stain and supragingival calculus compared to baseline and control. Though PX was more effective than LA in the control of plaque, this study indicates that both LA and PX were effective agents in a regimen for the control of plaque and gingivitis.

Adult↗

PubMed1989

Effects of 6 months use of an antiseptic mouthrinse on supragingival dental plaque microflora.

This study was undertaken to determine whether long-term use (6-months) of an antiseptic mouthrinse (Listerine Antiseptic, Warner Lambert Co., Morris Plains, NJ, USA) led to an undesirable succession of oral pathogens or the emergence of resistant microbial forms. Supragingival plaque was collected from 83 subjects before treatment and after either 3 or 6 months use of either the active antiseptic or a 5% hydroalcohol control. Subjects rinsed with their assigned mouthrinse twice daily under supervision. The plaque samples were analyzed for microbial content by darkfield microscopy, culture on a series of nonselective and selective bacterial media, and by recognition of microbial forms by recognition of distinct colony on a nonselective medium. Statistical analysis of the results revealed no significant microbial shifts including no significant increases in presumptive oral pathogens, spirochetes, black-pigmented Bacteroides, Streptococcus mutans, or Candida albicans. Additionally, no detectable rise in either staphylococci or enteric bacteria, potential opportunistic pathogens, was observed.

Adolescent↗

PubMed1989

Periodontal disease and oral microbial successions during myelosuppressive cancer chemotherapy.

Factors contributing to the succession of opportunistic pathogens at oral sites, including the periodontium, during myelosuppressive chemotherapy are poorly understood. This study examined the relation of periodontal disease to qualitative and proportional shifts in the oral microflora of 21 acute nonlymphocytic leukemia patients (7 male and 14 female, mean age (range) = 51.0 (25-81 years) observed during standardized myelosuppressive regimens. Supra- and subgingival microbial plaque specimens were individually collected from 2 contralateral oral sites (distobuccal of teeth 1-6 and 3-6) in each participant at hospital admission (day 1) and during point of maximal myelosuppression (day 14). Periodontal disease indices obtained at day 1 included site-specific measures of attachment loss and clinical assessment of disease status. Using a residualized change score analysis, periodontal disease status and attachment loss were positively correlated with increases in the proportional recovery of Staphylococcus sp. from supragingival sites and total yeast from supra- and subgingival sites. When age-related covariation in the microbial shifts was controlled in the analysis, periodontal disease status and attachment loss demonstrated no significant correlation with increases in total yeast at supragingival sites. These findings suggest that host factors such as periodontal disease may contribute to patterns of oral microbial successions during cancer chemotherapy.

Adult↗

PubMed1989

Chemotherapeutic inhibition of supragingival dental plaque and gingivitis development.

A 6-month double-blind, controlled clinical study was conducted on 107 healthy adult subjects to determine the efficacy of a mouthrinse used as a supplement to regular oral hygiene measures on supragingival dental plaque and gingivitis. 115 healthy adult patients were recruited for the study. Following screening examinations for minimal entry levels of existing gingivitis and plaque in patients with a minimum of 20 sound natural teeth, extrinsic tooth stain, gingivitis and plaque index scores were recorded. Soft tissues were evaluated. All subjects then received a complete dental prophylaxis, removing plaque, calculus and extrinsic stain. Utilizing their normal oral hygiene, subjects began a regimen of rinsing with 20 ml of the randomly assigned rinse, twice daily for 30 s for 6 months. 7 days after prophylaxis, gingivitis was again scored (baseline 2). Soft tissue, gingivitis, plaque area and extrinsic stain were evaluated again at 3 and 6 months. Results demonstrated that after 6 months, listerine produced a 34% inhibition of both plaque and of gingivitis compared to a hydroalcohol control (p less than 0.001).

Adolescent↗

PubMed1987

Microbiology of acute periodontal infection in myelosuppressed cancer patients.

This study characterized the subgingival microbial flora associated with 27 acute exacerbations of preexistent periodontal disease in 24 patients with chemotherapy-induced myelosuppression. All but two acute periodontal infections developed at low granulocyte levels (less than 1,000/microL). Suspected pathogens were detected in high concentrations in subgingival plaque specimens in 17 episodes of acute periodontal infection; a single pathogen was recovered in ten acute infections, and more than one pathogen was recovered in seven acute infections. Staphylococcus epidermidis, Candida albicans, S aureus, and Pseudomonas aeruginosa predominated, with combinations of these detected in some patients. Concomitant bacteremias developed in two of these patients. The subgingival microflora associated with ten acute periodontal infections was characterized by predominantly indigenous microorganisms, which in nine episodes were in abnormal proportions compared with microbial profiles in noncancer patients with similar degrees of periodontal disease. These data demonstrate that pathogens normally associated with infections in myelosuppressed cancer patients, as well as indigenous oral flora, are associated with acute periodontal infections during granulocytopenia. This finding is important, since this body site has not commonly been recognized as a source for acute infection in these patients.

Acute Disease↗

PubMed1986

Metabolic differences between saliva from caries-active and caries- and restoration-free children.

Sucrose consumption and lactic-acid production by saliva, and the effects of pH, were first evaluated by radio-isotope techniques in populations of caries- and restoration-free (CF), and caries-active from sucrose than saliva from CA subjects. Sucrose consumption also was significantly greater in saliva of CF subjects. These results occurred at pH 7.2 but not at pH 6.0 and 5.0. Lactic acid, total volatile products and carbon-dioxide (CO2) production by saliva were then evaluated in different CF and CA populations of children. Metabolic parameters in the presence and absence of salivary supernatant (SS) also were determined. Saliva of these CF subjects also formed significantly more lactic acid from sucrose than did CA subjects. The presence of SS increased lactic-acid formation in this saliva; the increase was significant in CF subjects. Total volatile products and CO2 were greater in saliva of CF subjects but were not affected by SS. Partial microbial characterization of each salivary specimen was conducted in both series of experiments. CF subjects harboured less Streptococcus mutans (parts I and II), total lactobacilli (parts I and II) and Actinomyces species (part II) than CA subjects. Differences for lactobacilli in the first population and Actinomyces species in the second were significant.

Child↗