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Biomedical subjects

C Romond

Publications and source records attributed to C Romond.

At least 19 recordsLinked to original sources
PubMed1992

Bacterial microleakage of Cavit, IRM, and TERM.

In this in vitro study, a model system was developed and tested to evaluate the sealing ability of temporary restorative materials used in endodontic access preparations. The materials studied, Cavit, IRM, and TERM, were tested on 40 premolars against a known bacterial species, Streptococcus sanguis. The leakage of bacterial cells was checked 4 and 8 days after initial immersion in the culture. Thermocycling was introduced on the fourth day. After 8 days the cement thicknesses were measured after the teeth had been longitudinally sectioned. Before and after thermocycling, IRM was less leakproof than Cavit (p < 0.05) and TERM (p < 0.05). Thermocycling aggravated percolation in the case of IRM, and decreased the tightness of Cavit, whereas TERM remained leakproof. The thicknesses were as follows: Cavit, 3.73 mm; IRM, 3.45 mm; and TERM, 5.49 mm. There was no statistically significant relationship between thickness and tightness.

Analysis of Variance↗
PubMed1992

In vitro effects of titanium powder on oral bacteria.

Biomaterial research has been mostly concerned with biocompatibility, i.e. tissue response, of materials for dental or orthopaedic implantation. In this study, the effects of titanium powder on seven bacterial species commonly found in dental plaque or gingival sulcus, were determined by agar incorporation and by liquid medium culture. In neither culture system could any inhibitory or stimulatory activity be detected.

Bacteria↗
PubMed1992

Regulation of the bacterial intestinal implantation in infant born by caesarean section.

Studies were undertaken to determine the regulation of the bacterial intestinal implantation in 19 newborns delivered by caesarean section. Correlation was made with the infant feeding mode. The effect of human milk seemed to be the result of B. bifidum proliferation, in contrast to artificial alimentation that seemed to favour C. perfringens implantation. The question was raised by us as to whether this opposition was only related to alimentation. In fact, B. bifidum itself also had an effect as demonstrated by the lower mean counts of C. perfringens in bottle-fed infants carrying the bifido-bacterial flora (P = 0.05). None of the other faecal bacteria investigated in this study led to the same decrease.

Bacteria↗
PubMed1991

Treatment of diversion colitis by short-chain fatty acids. Prospective and double-blind study.

Diminished production of short-chain fatty acids (SCFA) by altered flora has been suggested in the pathogenesis of diversion colitis (DC). We evaluated prospectively the effectiveness of SCFA irrigation in 13 patients with excluded colon (eight males, five females; mean age, 48 years). The causes of diversion were inflammatory bowel disease (n = 4), colonic cancer (n = 2), sigmoid diverticulitis with perforation (n = 3), ischiorectal abscess (n = 2), and miscellaneous (n = 2). Patients were given, twice a day for 14 days in a double-blind manner, a 60-ml enema containing either SCFA (acetate: 60 mmol/liter; propionate: 30 mmol/liter; and N-butyrate: 40 mmol/liter) (Group 1; n = 7) or isotonic NaCl (Group 2; n = 6). Endoscopy with biopsies was performed before starting the trial (D1) and 14 days later (D14). On D1 all patients had endoscopic and histologic findings suggestive of DC. No endoscopic or histologic changes were observed on D14 in either group. We conclude that endoscopic and histologic lesions of DC were not improved by SCFA irrigation during the 14 days.

Adult↗
PubMed1991

Phenotypic differentiation of bifidobacteria of human and animal origins.

The phenotypes of 153 strains belonging or related to the genus Bifidobacterium were studied. These organisms included 38 collection strains and 115 wild strains (41 strains of human origin, 56 strains of animal origin, and 18 strains obtained from rivers or sewage). Our phenotypic analysis revealed seven main groups that were subdivided into 20 subgroups. Seven subgroups contained no type or collection strain. Among the human strains, the type strains of Bifidobacterium pseudocatenulatum and B. catenulatum fell into group I, which contained the type strains of B. adolescentis (subgroup Ib), B. dentium (subgroup Ic), and B. angulatum (ungrouped). The type strain of B. breve belonged to subgroup IIIa1, and the type strains of B. infantis and B. longum fell into subgroup IIIb1. Group VII comprised only wild strains that were isolated from human infant feces. Among the animal strains, group II consisted mainly of bifidobacteria that were isolated from pig feces and contained the type strains of B. suis (subgroup IIb), B. thermophilum (subgroup IIf), B. choerinum, and B. boum (ungrouped). Wild strains belonging to group V were isolated from pig, calf, cow, and chicken feces; this included the type strains of B. animalis (subgroup Va), B. magnum (subgroup Vb), B. pseudolongum, and B. globosum (subgroup Vc). The strains of human origin (groups I, III, and VII) were well separated from the animal strains (groups II, IV, and V). It was not surprising that the wild strains isolated from surface water or sewage were distributed in the animal groups as well as the human groups. Thus, bifidobacteria can be considered to be successful indicators of human or animal fecal pollution when they are correctly classified. The acidification patterns were not adequate to differentiate Bifidobacterium species, as determined previously by Mitsuoka (Bifidobacteria Microflora 3:11-28, 1984) and Scardovi (p. 1418-1434, in P. H. A. Sneath, N. S. Mair, M. E. Sharpe, and J. G. Holt, ed., Bergey's Manual of Systematic Bacteriology, vol. 2, 1986). However, enzymatic tests furnished new taxonomic criteria for the genus.

Adult↗
PubMed1991

Nosocomial infections of ocular conjunctiva in newborns delivered by cesarian section.

Colonization of the ocular conjunctiva in newborns delivered by cesarian section occurs usually within the first day of life. We have studied the flora of the ocular conjunctiva at birth, from 19 newborns delivered by cesarian section, coming from two different maternity hospitals. Ocular conjunctiva cultures yielded the main predominant flora in both maternity hospitals considered. The most common genus of this flora are: Staphylococcus, Corynebacterium and Propionibacterium acnes. Peptostreptococcus productus, Neisseria, Eubacterium and Clostridium perfringens are isolated occasionally. In newborns delivered by cesarian section, this flora principally acquired may be the consequence of the presence of bacteria in the ambient air, as well as differences in care provided by the nosocomial personnel.

Bacteria, Aerobic↗
PubMed1991

Gram(+) anaerobic intestinal cocci in healthy adults and neonates.

Anaerobic gram(+) cocci were found to be part of the normal indigenous flora of the intestinal tract in healthy adults (19.6%) but they were rarely isolated from healthy neonates (6.1%). A larger variation of species was also present in adults. Their installation in the newborn's intestine seems to be partially inhibited by factors that are not at present very clear.

Adolescent↗
PubMed1991

[Behavior of Clostridium perfringens in the intestine of newborn infants born by cesarean section].

Colonization of the digestive tract by C. perfringens was studied in infants born by cesarean section. Correlations between the level of colonization and the environment, type of feeding, and presence of other anaerobic bacteria were looked for. Colonization by C. perfringens was found as early as the second day of life in one of the maternity wards studied, suggesting presence of the microorganism in the environment. By the 14th day of life, colonization with C. perfringens was demonstrated in all the bottle-fed or breast and bottle-fed infants. In strictly breast-fed infants, findings suggested antagonism between Bifidobacterium and C. perfringens. Bacteroïdes and Clostridium species other than C. perfringens were not found prior to colonization by C. perfringens.

Bifidobacterium↗
PubMed1991

Survival of Prevotella intermedia (Bacteroides intermedius) in transport media.

Five transport media were selected for testing, in vitro, the survival of a pure strain of Prevotella intermedia (Bacteroides intermedius) for 6, 24, and 72 hours. Two were non-nutrient transport media (RTF and VMG IV). The three others (TG, PY, PYG) were nutrient media. An increase in the transport time, and manipulations in an aerobic atmosphere compromised the survival of the bacteria. PY ensured good survival of the bacteria. RTF seems to be the best medium for the transport of P. intermedia, when quantitative analysis is required.

Adult↗
PubMed1990

Apparition of Clostridium sp. and Bacteroides in the intestine of the newborn delivered by cesarian section.

Anaerobic flora plays a key role in preventing intestinal colonization with potential pathogens. Nowadays, the mechanisms involved in the colonization resistance provided by the anaerobic microflora are to be clarified. Numerous factors seem to intervene in the regulation of the intestinal flora. The purpose of the present study was to correlate the presence or relative absence of Clostridium sp. and Bacteroides with the colonization by C. perfringens, which is involved in lethal infections in an immunologically compromised host. The intestinal bacterial colonization of 20 newborns delivered by cesarian section was assessed sequentially over the first 14 days of life. C. perifringens is a strongly reducing microorganism and undoubtedly causes a decrease in the oxidoreduction potential of the newborn feces favouring the subsequent colonization by other putrefactive bacteria. C. perfringens seems to be the precursor for installation of putrefractive bacteria, as Bacteroides and other Clostridium sp.

Anaerobiosis↗
PubMed1990

In vitro survival of Bacteroides intermedius in five transport media, alone or in the presence of Streptococcus sanguis.

The survival rate of Bacteroides intermedius was first tested in monoculture, and Streptococcus sanguis was then added in 5 different transport media; 2 nonnutritious media, the viability-preserving medium of the University of Göteborg No. IV (VMG IV), reduced transport fluid (RTF), and 3 nutritious media, thioglycolate medium (TG), peptone yeast extract medium (PY) and PY medium with 1% glucose (PYG). All manipulations were carried out in an anaerobic chamber. After a given transport time (6 or 24 h) aliquots were spread on plates containing solid PY medium by means of an automated spiral system device, thus permitting counts after incubation. The slight variations in the counts of B. intermedius in monoculture, not exceeding 0.5 log10 in the 5 media tested, indicated its good survival capability, i.e. at least 24 h. By contrast, when S. sanguis was added, it was only possible to use nutritious media such as PY or TG for 6 h. In the glocose-containing media (PYG, TG), the multiplication of rapidly glucose-fermenting microorganisms such as streptococci influenced the B. intermedius survival rate. Therefore, the transport time for oral microbiological samples needs to be reduced as much as possible. The use of excessively rich media (particularly media containing a high level of glucose) should be avoided.

Antibiosis↗
PubMed1990

Occurrence of Bifidobacterium in the feces of newborns delivered by cesarean section.

In cesarean section newborns, colonization by Bifidobacterium occurs generally within 4 days of life. Breast-fed infants, independent of the delivery procedure, harbor a gastrointestinal flora characterized by a predominance of Bifidobacterium. Breast-fed [corrected] newborns delivered by cesarean section present a predominance of Bifidobacterium bifidum and bifidobacterium infantis in their stools. Investigation of variation in the incidence of Bifidobacterium among cesarean section newborns shows a larger variety of bifidobacterial species in an urban hospital. The prevalence of Bifidobacterium is lower in a newly constructed suburban hospital. Alimentation and environment hence seem to constitute important factors in the control of bifidobacterial flora.

Bifidobacterium↗
PubMed1990

Effect of the feeding practices on the establishment of bacterial interactions in the intestine of the newborn delivered by cesarean section.

The purpose of this study was to clarify the role of the intestinal anaerobe bacteria colonizing the intestine of the newborn delivered by cesarean section. The intestinal bacterial colonization of 18 newborns delivered by cesarean section was assessed sequentially over the first 14 days of life. Emphasis is placed on C. perfringens and upon interaction to other bacteria. Correlation was made with the infant feeding mode. Microbial studies were realized in anaerobic conditions using Columbia blood agar simple and supplemented with antibiotics. Artificial alimentation seemed to favour C. perfringens installation, in contrast to the maternal one which promote B. bifidum proliferation. Antagonism between these bacteria seems to be established in the newborn intestine, via the alimentation.

Bifidobacterium↗
PubMed1990

Occurrence of Enterobacteriaceae and E. coli in the intestine of the newborn by caesarean section.

It has been established that colonization of the gastrointestinal tract by Enterobacteriaceae and especially E. coli in newborn delivered by caesarean section occurs generally within the second day of life. On the 14th day, these bacteria inhabit the fecal flora of the majority of newborn. Hospital environment, as well as type of feeding do not seem to influence their frequency nor their level in the intestine of the infants born by caesarean section.

Cesarean Section↗
PubMed1990

[Host-Bifidobacterium interactions in the axenic mouse: partial characterization of bifidogenic factors in the intestinal contents].

Growth factors for Bifidobacterium bifidum were detected in faeces of axenic mice strain C3H. Most of these factors were found in the nondialyzable fraction obtained after aqueous extraction and dialysis. SDS-PAGE and filtration chromatography on Sepharose 4B revealed that many glycosylated components harbored a bifidigenic activity. Intestinal colinization of mice by B. bifidum involved the utilization and eventually the disappearance of the intestinal bifidigenic factors. There was no change in the protein concentration in fecal extracts, but the total hexose concentration was lower. Comparison of electrophoretic PAGE profiles after periodic acid Schiff coloration showed that bacteria used up the glycosylated fractions of many glycopeptides, particularly those of mucins and four glycoproteins. There was no correlation between the hexose concentration detected in every active fraction and the degree of in vivo degradation of bifidigenic factors. The attack on active glycopeptides having a molecular mass greater than 670 kDa thus revealed hexose sites that were not detectable previously by the phenol - sulfuric acid method. However, the amount of bifidigenic factors detected in vitro allowed us to measure the importance of the degradation of a component by B. bifidum in vivo.

Animals↗
PubMed1990

[Detection of beta-lactamases in the Bacteroides fragilis group].

One hundred and thirty three strains of Bacteroides fragilis group isolated from clinical specimen were tested for beta-lactamase activity against five beta-lactam antibiotics, ampicillin, cefaloridin, cefuroxime, cefotaxime and cefoxitin. The Minimal Inhibitory Concentration of antibiotics was determined using the agar dilution method. Beta-lactamase production was detected by a microbiological method in 128 of the 133 (96%) strains. The detected beta-lactamases had a broad-spectrum activity, hydrolyzing both penicillins and cephalosporins (101 strains). Some strains had a wide activity against beta-lactam antibiotics, including cefoxitin (7 strains); among these strains, 3 were found hydrolyzing imipenem.

Anti-Bacterial Agents↗
PubMed1989

Impaired bacterial flora in human excluded colon.

We compared the rectal microflora of 16 patients with surgically excluded colorectum with 16 healthy controls. The cause of diversion was inflammatory bowel disease (n = 10), colon cancer (n = 3), miscellaneous (n = 3). Six patients had a diversion colitis. In the excluded colorectum, the total bacterial count was only slightly lower than controls but the variety of the flora was significantly reduced. This reduction was confined to strict anaerobes, mainly the genus Eubacterium and Bifidobacterium. Among aerobes, enterobacteria were more often isolated than in controls. This altered microflora of excluded colorectum could be involved in the mucosal damage observed in some cases.

Adult↗