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Biomedical subjects

L A Devriese

Publications and source records attributed to L A Devriese.

At least 73 records · Page 4Linked to original sources
PubMed1999

Comparison of direct and enrichment methods for the selective isolation of vancomycin-resistant enterococci from feces of pigs and poultry.

Isolation results of vancomycin-resistant enterococci (VRE) of fecal samples from pigs and broiler and layer chickens obtained with two vancomycin-supplemented enrichment media, kanamycin aesculin azide (KAA) broth and Enterococcosel (ECC) broth, and three isolation media, KAA agar, ECC agar, and Slanetz and Bartley (SL) agar, were compared. Direct isolation on vancomycin-containing agar plates was not efficient in swine and layer chickens, which had only low numbers of VRE. In broilers chickens, the VRE content of the samples was high, and SL as well as ECC were found to perform better than KAA agar. The same three agar media were used as selective plating media after 1 and 2 days incubation of the samples in KAA and ECC enrichment broths. Sensitivities of the 12 different enrichment-plate combinations tested ranged from 0 to 81% in layer chickens and from 5 to 44% in samples from pigs. In the high prevalence type of samples from broilers, sensitivities still varied substantially from 52 to 78%. Incubating vancomycin-containing enrichment broths for 2 days compared with 1 day was favorable for the isolation of vancomycin-resistant Enterococcus faecalis, E. gallinarum, and E. casseliflavus but not for E. faecium and E. hirae/E. durans. ECC broth and ECC plates yielded the highest number of E. gallinarum and E. casseliflavus. In layer as well as in broiler chickens, ECC broth incubated for 2 days and plated on ECC agar was the most sensitive method. In pigs, however, KAA broth incubated for 2 days and plated on ECC medium yielded the highest number of VRE.

Animals↗
PubMed1999

Streptococcus intestinalis Robinson et al. 1988 and Streptococcus alactolyticus Farrow et al. 1984 are phenotypically indistinguishable.

The one-dimensional whole-cell protein patterns and a variety of biochemical characteristics of the type and reference strains of Streptococcus intestinalis and Streptococcus alactolyticus were studied. All the data revealed that strains of both species were indistinguishable. Reported differences in haemolytic activity and presence of Lancefield antigens were not reproduced. All strains were alpha-haemolytic. The S. intestinalis type strain possessed the group G antigen, but a second S. intestinalis reference strain and all of the S. alactolyticus strains possessed the group D antigen. All strains produced urease activity (albeit some after prolonged incubation), a characteristic considered important for S. intestinalis. Given the congruence between whole-cell protein electrophoresis and percentage of DNA-DNA hybridization, these data suggest that Streptococcus intestinalis Robinson et al. 1988 is a junior synonym of Streptococcus alactolyticus Farrow et al. 1984.

Animals↗
PubMed1999

Streptococcus pluranimalium sp. nov., from cattle and other animals.

Strains from subclinical mastitis, from the genital tract and tonsils of cattle, from tonsils of a goat and a cat and from the crop and the respiratory tract of canaries were found to constitute a new streptococcal species, for which the name Streptococcus pluranimalium sp. nov. is proposed. Sequencing of 16S rRNA showed that Streptococcus thoraltensis and Streptococcus hyovaginalis were its closest known phylogenetic relatives. The new species showed some phenotypic resemblance to the poorly described species Streptococcus acidominimus, but whole-cell protein analysis and 16S rRNA sequencing revealed that the new species was only distantly related to the type strain of S. acidominimus. Identification of these bacteria, which showed heterogeneous biochemical reaction patterns, was most reliably made by whole-cell protein analysis. Nevertheless, a number of biochemical reactions can be used to differentiate S. pluranimalium from other animal streptococci. Strain LMG 14177T, isolated from mastitic milk of a dairy cow, was designated as the type strain of S. pluranimalium sp. nov.

Animals↗
PubMed1999

Phenotypic distinction in Enterococcus faecium and Enterococcus faecalis strains between susceptibility and resistance to growth-enhancing antibiotics.

Susceptibility of Enterococcus faecium and Enterococcus faecalis strains from animals and foods to growth-promoting antibiotics used in animal feed was tested by the agar dilution technique. Acquired resistance to bacitracin, narasin, tylosin, and virginiamycin was seen for both species, and for E. faecium, resistance to avilamycin and avoparcin was also seen. Drawing the distinction between susceptibility and resistance based on frequency distributions of MICs was easy with avoparcin, avilamycin, and tylosin but difficult with virginiamycin and to some extent also with bacitracin and narasin.

Animals↗
PubMed1999

Comparison of glycopeptide-resistant Enterococcus faecium isolates and glycopeptide resistance genes of human and animal origins.

One hundred thirty-two glycopeptide-resistant Enterococcus faecium (GREF) isolates from different hospitals and pig and poultry farms in Belgium were compared on the basis of (i) their antibiotic susceptibilities, (ii) their SmaI pulsed-field gel electrophoresis (PFGE) patterns, and (iii) the organization of their Tn1546 or related elements in order to detect possible phenotypic and genotypic relationships among both groups of isolates. Human and animal vanA-positive GREF isolates were found to have similar susceptibility patterns; they remained susceptible to gentamicin and were, in general, susceptible to ampicillin. PFGE demonstrated a very high degree of genomic heterogeneity in both groups of isolates. However, indistinguishable isolates were found within different farms or hospitals, and in two instances, epidemiologically unrelated pig and human isolates showed indistinguishable PFGE patterns. In total, eight different transposon types were identified, and all were related to the prototype transposon Tn1546. The two predominant types, Tn1546 and type 2 transposons, which differed at three band positions, were present in both human and animal isolates. Type 2 transposons were significantly associated with pig isolates. The other types were seldom detected. These data suggest a possible exchange of glycopeptide resistance markers between animals and humans.

Animals↗
PubMed1999

Identification of nonlipophilic corynebacteria isolated from dairy cows with mastitis.

Nonlipophilic corynebacteria associated with clinical and subclinical mastitis in dairy cows were found to belong to four species: Corynebacterium amycolatum, Corynebacterium ulcerans, Corynebacterium pseudotuberculosis, and Corynebacterium minutissimum. These species may easily be confused. However, clear-cut differences between C. ulcerans and C. pseudotuberculosis were found in their acid production from maltotriose and ethylene glycol, susceptibility to vibriostatic agent O129, and alkaline phosphatase. Absence of growth at 20 degrees C and lack of alpha-glucosidase and 4MU-alpha-D-glycoside hydrolysis activity differentiated C. amycolatum from C. pseudotuberculosis and C. ulcerans. The mastitis C. pseudotuberculosis strains differed from the biovar equi and ovis reference strains and from caprine field strains in their colony morphologies and in their reduced inhibitory activity on staphylococcal beta-hemolysin. C. amycolatum was the most frequently isolated nonlipophilic corynebacterium.

Acids↗
PubMed1998

Verrucous endocarditis due to Escherichia coli in a Persian cat.

Verrucous endocarditis of the aortic valves was diagnosed postmortem in a Persian cat that died after showing clinical signs of dyspnoea, hypothermia and anorexia. Bacterial colonies were evident on Giemsa-stained sections of the valves and Escherichia coli was isolated from the endocarditis lesions.

Animals↗
PubMed1998

Characterization of four Flavobacterium columnare (Flexibacter columnaris) strains isolated from tropical fish.

Four Flavobacterium columnare strains (AJS 1-4) were isolated from black mollies (Poecilia sphenops) and platies (Xiphophorus maculatus), showing white spots on the back, head and skin ulcers. The isolates developed characteristic rhizoid yellow pigmented colonies on Shieh agar and typical growth in Shieh broth. They were Gram-negative, filamentous bacteria exhibiting flexing movements. When compared to F. columnare strains isolated from temperate fish, it was noted that the four strains originating from tropical aquarium fish are more capable of growing at higher temperatures, the opposite being true for the strains isolated from temperate fish. Biochemical characterization and agglutination tests proved that the isolated strains could be classified as F. columnare. Low minimal inhibitory concentration (MIC) values were found for chloramphenicol, erythromycin, furazolidone, kanamycin, lincomycin, nalidixic acid, oxytetracycline and streptomycin. MIC values were high for colistin, sulfamethoxazole and neomycin. Pathogenicity studies were performed on black mollies. When these animals were submersed in an infective solution of the F. columnare strains, a marked difference in virulence was noted among the four isolated strains, strain AJS 1 being the most virulent one and strain AJS 4 being of low virulence.

Agglutination Tests↗
PubMed1998

Identification of porcine Serpulina strains in routine diagnostic bacteriology.

Serpulina strains from pigs were identified using simple tests. The large size of S. hyodysenteriae in stainings from colonic contents and faeces was found useful for the presumptive differentiation of this major pathogenic species from the other Serpulinae. However, this morphological characteristic gets lost upon cultivation. The 'ring phenomenon' aided to confirm the strong haemolysis typical for S. hyodysenteriae. The weakly haemolytic species S. innocens, S. pilosicoli, S. intermedia and S. hyodysenteriae could be differentiated with the help of the indole spot test and two or four other simple enzymatic tests. Nearly half of the S. hyodysenteriae strains isolated in Belgium were indole-negative. Such strains have only rarely been reported earlier, and were absent among the strains from other European countries examined.

Animals↗
PubMed1998

Identification of streptococci from Greek Kasseri cheese and description of Streptococcus macedonicus sp. nov.

Taxonomic studies were performed on some Streptococcus-like organisms isolated from naturally fermented Greek Kasseri cheese. By SDS-PAGE analysis of whole-cell proteins the group was found to be quite different from Streptococcus thermophilus. Comparative 16S and 23S rRNA sequence analyses showed that the isolates represent a new species within the genus Streptococcus, where they are most closely related to the Streptococcus bovis cluster. On the basis of these phylogenetic results and some phenotypic differences, a new species, Streptococcus macedonicus, is proposed. The type strain is ACA-DC 206.

Bacterial Proteins↗
PubMed1998

Phylogenetic diversity of Streptococcus suis strains of various serotypes as revealed by 16S rRNA gene sequence comparison.

The 16S rRNA gene sequences of reference strains of Streptococcus suis serotypes 1-34 and 1/2 were determined. A comparative sequence analysis showed that the degree of sequence similarity between S. suis reference strains ranged from 93.94 to 100%. A dendrogram was constructed from the similarity matrix. Thirty-two strains representing 32 serotypes fell into a major group divided into three clusters. The other strains, S. suis serotypes 32, 33 and 34, were more distant. Biochemical characterization of the six more distant strains, including S. suis serotypes 20, 22, 26, 32, 33 and 34, revealed a profile similar to that of other S. suis serotypes. Comparison of the 16S rRNA gene sequences of S. suis reference strains with sequences of other members of the genus Streptococcus indicated that, with the exception of S. suis serotypes 32, 33 and 34, reference strains did not cluster with any other species in the genus. In conclusion, 16S rRNA gene sequence analysis defined a major group of S. suis reference strains which were very closely related and a higher divergence for S. suis serotypes 32, 33 and 34. However, to date, there is no strong evidence to reclassify strains of these serotypes in another species.

Animals↗
PubMed1998

Differentiation between Streptococcus gallolyticus strains of human clinical and veterinary origins and Streptococcus bovis strains from the intestinal tracts of ruminants.

Strains formerly identified as Streptococcus bovis were allotted to two groups by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of whole-cell proteins. Strains from humans with infections, mostly patients with endocarditis, and strains from pigeons with septicemia clustered with the recently described species Streptococcus gallolyticus. The original S. bovis type strain and strains exclusively from ruminants formed the second cluster. The findings indicate that S. gallolyticus is more likely to be involved in human and animal infections than S. bovis. Growth characteristics and several biochemical reactions were found to be useful in the differentiation of S. gallolyticus from S. bovis.

Animals↗
PubMed1998

Typhlitis caused by intestinal Serpulina-like bacteria in domestic guinea pigs (Cavia porcellus).

Between January 1992 and December 1996, Serpulina-like bacteria were demonstrated in intestinal tract lesions from 37 of 88 guinea pigs submitted to the University of Ghent in Ghent, Belgium, for necropsy because of disease and death from different unknown causes. All infected animals had a history of sudden death with minimal introductory clinical signs. Occasionally, they produced yellow, slimy feces or showed nervous signs, but the condition always had a fatal outcome within 24 h. When larger colonies of guinea pigs were involved, the disease spread very rapidly unless treatment with ronidazole was initiated. Lesions consisted of a catarrhal or hemorrhagic inflammation of the colon and cecum (typhlitis). Electron microscopy demonstrated the presence of large numbers of Serpulina-like organisms adhering to the cecal mucosae of these animals. Attempts to isolate the agents failed. The organisms did not stain by an immunofluorescence technique for the detection of Serpulina hyodysenteriae. The present data provide evidence that intestinal Serpulina-like organisms can be important as a cause of disease in guinea pigs.

Animals↗
PubMed1998

Effects of different test conditions on MICs of food animal growth-promoting antibacterial agents for enterococci.

The influence of the addition of sheep blood to Mueller-Hinton II agar and the effects of aerobic incubation with or without CO2 and of anaerobic incubation were tested with bacitracin, tylosin, avoparcin, virginiamycin, avilamycin, narasin, and flavomycin on enterococci. The antibacterial activity of bambermycin (Flavomycin) was strongly inhibited by the addition of blood, except with the species Enterococcus faecium, Enterococcus mundtii, Enterococcus hirae, Enterococcus casseliflavus, and Enterococcus gallinarum, which were not susceptible to this antibiotic on blood-free medium. With all other antimicrobials except avoparcin and tylosin, the presence of blood resulted in MIC increases of 1 to 3 log2 differences. Incubation in aerobic or anaerobic atmospheres enriched with CO2 lowered the susceptibility of enterococci to tylosin and increased their susceptibility to avilamycin, narasin, and avoparcin. This effect was most pronounced in tests on blood-free media. Results of susceptibility tests incubated under anaerobiosis and in a CO2-enriched atmosphere did not differ. For all enterococcal species, the preferred conditions for testing the susceptibility are Mueller-Hinton II medium supplemented with blood and incubation in a CO2-enriched atmosphere. However, when only E. faecium and Enterococcus faecalis are being tested, Mueller-Hinton II medium without blood incubated aerobically gives satisfactory results.

Aerobiosis↗
PubMed1997

Enterococcus cecorum septicemia in a malnourished adult patient.

Enterococcus cecorum, a species typically isolated from chicken, pigs, calves, horses, ducks, cats, dogs, and canaries, was isolated from the blood of a patient with severe septicemia. The isolate was identified by conventional biochemical tests. Identity as Enterococcus cecorum was confirmed by SDS-PAGE analysis of whole cell protein. This is the first report of the isolation of Enterococcus cecorum in a clinical setting.

Adult↗