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C Romond

Publications and source records attributed to C Romond.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1989

New diagnostic methods for anaerobic bacteria.

The use of DNA probes and monoclonal antibodies as new diagnostic methods are described in this review. For each technique, the principles for preparation of reagents and the different immunological methods, in which monoclonal antibodies are used, are described. Specificities and sensitivities are discussed with special reference to anaerobic bacteria or their toxins. The two groups of methods are compared as rapid diagnostic methods for direct detection of anaerobes in patient samples. If we consider DNA probes, the radiolabelled are more sensitive and more specific, but results are obtained only after some days. Non-radioactive probes are less sensitive, but amplification procedures greatly enhance their sensitivity. Monoclonal antibodies give rapid results but their high specificity may be a disadvantage when the technique is used for rapid diagnostic purposes on patient samples. This problem may be reduced by the use of pools of several monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1988

[In vitro activity of an ofloxacin-metronidazole combination against anaerobic bacteria. Kinetics of the action of metronidazole against Bacteroides fragilis].

The activity of metronidazole combined with ofloxacin was investigated by the checkerboard method in liquid medium against 60 obligate anaerobes. The bacteriostatic effect of the combination was assessed by calculating the FIC index. Two metronidazole resistant strains of Propionibacterium acnes (MIC greater than 32 mg/l) were inhibited by 0.125 mg/l of this former antibiotic in presence of an ofloxacin concentration equal to half the value of the MIC. On the 58 other anaerobic strains, the combination of metronidazole plus ofloxacin had an additive bacteriostatic effect (30 strains) or a synergistic effect (26 strains). No antagonism was noted with any strain. For selected anaerobic or mixed infections the combination of metronidazole and ofloxacin may be useful. Killing curves demonstrated that, under good anaerobic conditions, metronidazole acted rapidly against Bacteroides fragilis. At a concentration of 8 mg/l, a decrease of log10 of the population was observed after 2 hours. After a contact ranging from 1 to 8 hours, depending of the investigated strains, a bactericidal effect was observed with metronidazole.

Anti-Bacterial Agents↗
PubMed1987

Bacterial colonization of the large intestine in newborns delivered by cesarean section.

Colonization of the gastrointestinal tract in newborns delivered by Cesarean section occurs during the first days of life by bacteria provided by the environment. It is more rapid in breast-fed infants than in bottle-fed babies. The intestinal flora is more diversified if the infants receive formula feeding. The first bacteria encountered are facultative anaerobes; they remain predominant during the first two weeks of life. In comparison to vaginal delivery, there were low levels of strict anaerobes after Cesarean section; members of the Bacteroides fragilis group were still completely lacking after 14 days of life and Bifidobacteria were only isolated sporadically.

Bacteria, Anaerobic↗
PubMed1987

In vitro activity of imipenem against gram-positive anaerobic bacteria.

The in vitro activity of imipenem, a new penem antibiotic, was determined against 210 clinical Gram-positive anaerobic isolates and compared with the activities of metronidazole, clindamycin, cefoxitin, moxalactam, ceftizoxime, ceftriaxone and cefotiam. All investigated strains were inhibited by a 4-mg/l concentration of imipenem. Cefoxitin demonstrated good activity against most strains with exception of some Clostridium difficile and Clostridium ramosum strains. Cephalosporins were classed in decreasing activity order as follows: cefoxitin moxalactam ceftriaxone ceftizoxime cefotiam. Metronidazole had better activity against Clostridium spp. than against non-sporulated bacilli. Clindamycin resistance rates were superior to 10% for most groups, with the exception of Clostridium perfringens. Actinomyces and Bifidobacterium. Imipenem was the most potent inhibitor, as 81% and 95% of tested strains were inhibited at concentrations of 0.25 and 0.5 mg/l respectively.

Anti-Bacterial Agents↗
PubMed1986

[In vitro activity of roxithromycin, new semisynthetic macrolide against obligate anaerobes].

The "in vitro" susceptibility to roxithromycin and three other macrolides of 236 anaerobes isolated from clinical samples in 1984/1985 was determined by an agar-dilution method on Wilkins Chalgren medium. 90% of Gram positive cocci were susceptible to both roxithromycin and josamycin (MIC less than 1 mg/l, whereas 1 mg/l erythromycin and 2 mg/l spiramycin were able to inhibit respectively 46 and 86% of the same tested strains. No resistance to the four macrolides was observed among Eubacterium, propionibacterium and Bifidobacterium. Two C. perfringens strains and one C. difficile strain were resistant to all four macrolides, while 97% of Clostridium sp. strains were inhibited by 4 mg/l erythromycin, josamycin or roxithromycin. Against Gram positive anaerobes, roxithromycin was equal or superior to erythromycin and spiramycin. At a concentration of 4 mg/l, roxithromycin inhibited 82% of B. fragilis strains. Roxithromycin and josamycin were more active against Gram negative bacilli that erythromycin and spiramycin. Macrolides had no effect on Fusobacterium strains. In this study, 4 mg/l roxithromycin inhibited 217 of the 236 anaerobic strains investigated (92%).

Bacteria, Anaerobic↗
PubMed1985

[Sensitivity of obligate anaerobes to ofloxacin, pefloxacin, enoxacin and norfloxacin].

The in vitro activity of four new quinolones against 355 obligate anaerobes was investigated. MICs were determined using the reference method of Sutter et al. [14]. The four fluorinated quinolones tested differ from nalidixic acid which is inactive on most anaerobes except for some Clostridium perfringens strains. All strains tested were inhibited by 64 and 16 mg/l pefloxacin and ofloxacin respectively. Except for Bacteroides, all strains were inhibited by 64 mg/l norfloxacin or enoxacin. Clostridium strains other than C. perfringens exhibited heterogeneity; C. difficile and C. ramosum had the highest MICs. Bacteroides fragilis proved less susceptible to fluorinated quinolones than the other obligate anaerobes. Ofloxacin showed the greatest activity, with 4 mg/l inhibiting 100% of C. perfringens and 83% of all anaerobes investigated.

Bacteria, Anaerobic↗
PubMed1985

Bacterial interactions.

Bacterial interactions are important both in the formation of polymicrobial abscesses and in the control of the balance of the natural human floras. Investigations of the mechanisms controlling normal flora might be based on gnotobiology, but most of the conclusions are at present obtained indirectly by observations of the flora composition. One example is the typical bifid flora observed during breast-feeding. We studied changes in this following the introduction of bottle-feeding.

Abscess↗
PubMed1985

[Sensitivity of strict anaerobic bacteria to metronidazole, cefoxitin, and clindamycin].

The minimal inhibitory concentrations of three antimicrobial agents were determined by two fold dilution in Wilkins Chalgren agar for over 569 anaerobes isolated and collected from 20 French hospitals. Metronidazole, cefoxitin and clindamycin inhibited respectively 95, 97 and 91% of tested strains. No metronidazole resistant strains could be found among Bacteroides fragilis group, Fusobacterium and Clostridium other than C. perfringens. Cefoxitin was the most active against C. perfringens, Gram positive cocci and non sporulated bacilli. Clindamycin resistance was observed mainly with B. fragilis and Clostridium other than C perfringens. This phenomenon occurred in most hospitals where strains were isolated.

Bacteria, Anaerobic↗
PubMed1984

[Microbiologic study of a new disinfectant: decyloxy-3-hydroxy-2-amino-1-propane hydrochloride].

Decominol exhibits bactericidal activity in a concentration of 0.05% (NF T 72-151). This concentration is increased five-fold in the presence of an albumin-yeast extract mixture, and 2.5-fold in the presence of hard water (60 degrees French). At pH 5.0, 0.5% concentration is not bactericidal (NF T 72-171) Fungicidal activity (T 72-201) is weak at 20 degrees and 50 degrees C and the sporicidal tests (T 72-231) establish the lack of sporicidal activity at 10%. Decyloxy-3 hydroxy-2 in 0.2 amino-1 propane hydrochloride to 1.5% concentrations used in a meat-canning factory ensures satisfactory disinfection of correctly cleansed surfaces. It also proves useful for sterilization of circuits where it can be used as an adjunct to the lethal action of heat.

Bacteria↗
PubMed1984

[Determination of virucidal activity. Value of the bacteriophage as a viral model].

Virucidal activity of six disinfectants was determined in vitro against bacteriophages T2, MS2 and phiX 174. The preliminary study shows the simplifications resulting from the use of bacteriophages for this kind of test: easy and reproducible production of stores of bacteriophages with controlled purity, good stability and concentration of at least 10(7) PFU/ml, and no limitation due to cytotoxicity. Virucidal concentrations determined for a 15-minute contact are 31.2 ppm (active chlorine) for hypochlorite solution, 10 ppm (iodine) for an iodophor, 1% for formaline, 0.5% for glutaraldehyde, more than 0.3% for a quaternary ammonium salt and more than 3% for an amphotere. The proposed method gives practical information for decontamination in bio-industry. Given the resistance noted with bacteriophages, this experimental method could be applied in a more general setting.

Coliphages↗