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Biomedical subjects

G Wauters

Publications and source records attributed to G Wauters.

At least 37 records · Page 2Linked to original sources

Identification of Arthrobacter oxydans, Arthrobacter luteolus sp. nov., and Arthrobacter albus sp. nov., isolated from human clinical specimens.

Five Arthrobacter isolates from clinical specimens were studied by phenotypic, chemotaxonomic, and genetic characterization. Two strains had characteristics consistent with those of Arthrobacter oxydans. One strain was related to A. citreus; however, DNA-DNA hybridization and phenotypic characteristics indicated that this strain belongs to a new species, for which the name Arthrobacter luteolus sp. nov. is proposed. Two strains were closely related to A. cumminsii by 16S rRNA gene sequencing, but DNA-DNA hybridization, peptidoglycan type, and some phenotypic features indicated that they should be assigned to a new species, for which the name Arthrobacter albus sp. nov. is proposed. The type strain of A. luteolus is CF25 (DSM 13067). The type strain of A. albus is CF43 (DSM 13068).

Arthrobacter↗

Production of enterotoxin by Yersinia bercovieri, a recently identified Yersinia enterocolitica-like species.

Yersinia bercovieri, a recently identified Y. enterocolitica-like species, produces a heat-stable enterotoxin (designated YbST) which has biologic activity in infant mice and increases short circuit current in Ussing chambers. Although YbST has some properties in common with the heat-stable enterotoxins of Y. enterocolitica (YST I and YST II), it appears to be a novel toxin because (i) it was not neutralized by anti-YST I antiserum, (ii) YbST-neutralizing antiserum did not neutralize YST I, and (iii) Y. bercovieri strains did not hybridize with genetic probes for yst I, yst II, and other known enterotoxins.

Animals↗

Prospective study of catalase-positive coryneform organisms in clinical specimens: identification, clinical relevance, and antibiotic susceptibility.

During a 6-month period, all clinical isolates of catalase-positive coryneform organisms, which were isolated during the routine processing of clinical specimens, were characterized in the laboratory of the 1800-bed University Hospital of Leuven. The distribution of the species in the corynebacteria was: Corynebacterium amycolatum 70 (53%), Corynebacterium jeikeium 16 (12%), Corynebacterium striatum 11 (8%), Corynebacterium afermentans 10 (7%), Corynebacterium minutissimum 9 (6%), CDC coryneform group G 4 (3%), Corynebacterium urealyticum 4 (3%), Corynebacterium glucuronolyticum 1 (0.7%), and Corynebacterium xerosis 1 (0.7%). Of the 150 isolates, 37 (25%) were considered to be infection related and the remaining 113 (75%) were of questionable clinical significance. Susceptibility of the corynebacteria to 12 antibiotics active against Gram-positive organisms was evaluated. C. amycolatum, C. jeikeium, and C. urealyticum were multiresistant, but all isolates were susceptible to teicoplanin and vancomycin. Most of the C. amycolatum strains, and all strains of C. jeikeium and C. striatum, were susceptible to the vibrocidal compound O/129.

Actinomycetales↗

Surveillance of human Yersinia enterocolitica infections in Belgium: 1967-1996.

Between 1967 and 1996, > 18,700 strains of Yersinia species, excluding Yersinia pestis, were recovered in Belgium from a variety of gastrointestinal and extraintestinal sites in patients. Full identification and serotyping were performed by the two Belgian reference laboratories. Yersinia enterocolitica serogroup O:3 predominated (79.4% of strains), followed by serogroup O:9 (11.1%). The remaining 9.5% of isolates belonged to serogroups and related species generally considered nonpathogenic. Acute enterocolitis was the most common clinical form of Y. enterocolitica infection, affecting primarily children younger than 5 years of age. Since 1967, there was a steady increase in isolations every year, with 305 cases in 1975 and up to 1,469 in 1986. From 1987 on, there was a clear decrease in the number of reported cases, although the number of participating laboratories and culture techniques remained constant. This significant decrease in the occurrence of Y. enterocolitica infections may be explained by changes in the slaughtering procedures and eating habits of the population.

Adolescent↗

Identification of Corynebacterium amycolatum and other nonlipophilic fermentative corynebacteria of human origin.

Four identification tests, proposed in addition to conventional methods, were evaluated with 320 fermentative nonlipophilic Corynebacterium strains: growth at 20 degrees C, glucose fermentation at 42 degrees C, alkalinization of sodium formate, and acid production from ethylene glycol. These tests were highly discriminant. Corynebacterium amycolatum displayed a unique profile, allowing it to be distinguished from similar species, such as C. xerosis, C. striatum, and C. minutissimum.

Corynebacterium↗

Sporadic case of listeriosis associated with the consumption of a Listeria monocytogenes-contaminated 'Camembert' cheese.

Listeria monocytogenes is an intracellular gram-positive organism responsible for severe infections in both humans and animals. Whereas the food-borne transmission of listeriosis was demonstrated in several outbreaks, most cases of listeriosis occur sporadically and are rarely linked with consumption of contaminated foods. In this paper a case of septicaemia with L. monocytogenes in a 73-year-old immunocompromised man is described. Evidence for the association of this case of listeriosis with the consumption of a contaminated 'Camembert' cheese is provided by serotyping, esterase typing, DNA macrorestriction patterns analysis and level of virulence of the isolated strains for mice.

Aged↗

Evaluation of chlorhexidine and silver-sulfadiazine impregnated central venous catheters for the prevention of bloodstream infection in leukaemic patients: a randomized controlled trial.

It has been suggested that central venous catheters impregnated with antiseptics such as chlohexidine and silver-sulfadiazine reduce the risk of catheter-related bacteraemia in intensive care patients. Patients suffering from haematologic malignancy treated by chemotherapy through a central venous catheter are at even greater risk of catheter-related bacteraemia. A prospective double-blind randomized controlled trial was performed in order to investigate the effectiveness of chlorhexidine and silver-sulfadiazine impregnated catheters (CH-SS) in these patients. A total of 680 catheters (13,826 catheter days) were inserted, of which 338 were antiseptic impregnated. Bloodstream infection was observed in 105 cases with an overall risk of 7.6 per 1000 catheter days. Thirty-two infections (30.5%) were catheter-related, corresponding to a risk of 2.3 per 1000 catheter days. There was no statistically significant different between the overall rates of bloodstream infection for impregnated and non-impregnated catheters (14.5 vs. 16.3%). The incidence of catheter-related infection was also similar in both groups (5 vs. 4.4%) and there was no difference in the time of the onset of bacteraemia in the two groups. It is concluded that the use of CH-SS catheters in patients with haematologic malignancy reduces neither the overall risk of bloodstream infection, nor the catheter-related infection rate, nor the delay for the occurrence of infection.

Adult↗

Unusual Yersinia enterocolitica strains recovered from domestic animals and people in New Zealand.

Twenty five isolates of Yersinia recovered from the faeces of cattle, sheep, goats and people in New Zealand were characterised biochemically and serologically and were found to be unrelated to any known Yersinia species. Two phenotypes were identified biochemically. Testing against all known O-factors of Yersinia showed that the isolates were serologically unique and two new serotypes were proposed, O:77 and O:78. Deoxyribonucleic acid relatedness studies indicated that the strains formed a homogeneous group, closely related to Yersinia enterocolitica. The definitive status of the isolates has not yet been decided.

Animals↗

Yersinia spp. and numbers, with particular reference to Y. enterocolitica bio/serotypes, occurring on Irish meat and meat products, and the influence of alkali treatment on their isolation.

Samples (n = 340) of Irish meat and meat products were examined to determine the incidence and initial numbers of Yersinia spp. present. In cases where no typical Yersinia colonies were observed, samples were cold enriched up to 21 days at 4 degrees C and streaked out on CIN agar with and without post-enrichment alkali treatment. The highest isolation rates of Yersinia were found using post-enrichment alkali treatment and an incubation temperature of 37 degrees C. All Yersinia isolates were identified to species level and Y. enterocolitica isolates were biotyped and serotyped. Pathogenic isolates (biotypes 1B-5) were examined for the presence of a virulence plasmid using dye binding reactions and agglutination tests. The incidence of Yersinia spp. was high on raw (89%) and cooked meats (49%) obtained fromdelicatessen counters but lower in pre-packaged cooked meats (18.8%). Initial numbers of Yersinia were generally < 2.7 log10cfu/g on raw meats and < 0.7 log10cfu/g on cooked.

Food Microbiology↗

Isolation of Arthrobacter spp. from clinical specimens and description of Arthrobacter cumminsii sp. nov. and Arthrobacter woluwensis sp. nov.

Arthrobacter spp. are very widely distributed in the environment (e.g., soil) but have not been described as causing disease in humans. Over a 6-year period, two reference laboratories isolated or received 11 strains which were eventually identified as belonging to the genus Arthrobacter. These strains had been initially identified as Centers for Disease Control and Prevention coryneform group B-1 and B-3 bacteria (whitishgrayish colonies of 2 mm or greater in diameter after 24 h of incubation, respiratory metabolism, absent or weak acid production from sugars, and hydrolysis of gelatin). However, chemotaxonomic investigations revealed lysine as the diamino acid of the cell wall and the presence of branched cellular fatty acids (with anteiso-pentadecanoic acid predominating) which was compatible with an assignment of the 11 isolates to the genus Arthrobacter only. Peptidoglycan and 16S rRNA gene sequence analyses demonstrated that three of the strains studied were representatives of a new Arthrobacter species for which the name Arthrobacter cumminsii sp. nov. is proposed and that one other strain represented a second new Arthrobacter species for which the name Arthrobacter woluwensis sp. nov. is proposed. This report is the first on the isolation of Arthrobacter spp. from clinical specimens.

Arthrobacter↗

Endocarditis of native aortic and mitral valves due to Corynebacterium accolens: report of a case and application of phenotypic and genotypic techniques for identification.

Endocarditis of native aortic and mitral valves due to an organism identified as Corynebacterium accolens developed in a 73-year-old patient without predisposing factors. The organism was identified as C. accolens by biochemical identification, amplified rRNA gene restriction analysis, and DNA-DNA hybridization. This is the first case of C. accolens endocarditis reported, adding to the increasing number of Corynebacterium-related cases of endocarditis.

Aged↗

Analysis of clinical and environment Yersinia isolates in the Republic of Georgia.

The Center for Infectious Diseases Control, Georgian Ministry of Health, isolated 2,493 Yersinia enterocolitica and Y. enterocolitica-like strains, 22 Y. pestis strains, and 21 Y. pseudotuberculosis strains from 130,574 clinical and environmental samples. Analysis of 100 Y. enterocolitica and Y. enterocolitica-like strains showed none to be within traditional pathogenic biogroups or serogroups, and none carried genetic markers for virulence. However, some strains were enterotoxigenic in infant mice, while others were associated with prolonged carriage in adult mice.

Adult↗

Specific detection of methicillin-resistant Staphylococcus species by multiplex PCR.

In Staphylococcus aureus, mecA and femA are the genetic determinants of methicillin resistance. By using a multiplex PCR strategy, 310- and 686-bp regions of the mecA and femA genes, respectively, were coamplified to identify susceptible (lacking mecA) and resistant (mecA+) staphylococci and to differentiate S. aureus (femA+) from coagulase-negative staphylococci (lacking femA). A third staphylococcal genomic sequence, corresponding to IS431 and spanning 444 bp, was used as a PCR control. One hundred sixty-five staphylococcal strains were tested. All 72 methicillin-resistant strains were found to be mecA+, and 92 of the 93 susceptible isolates lacked mecA. Only one coagulase-negative Staphylococcus isolate carrying the mecA gene was highly susceptible to oxacillin. The femA determinant was a unique feature of S. aureus; it was found in 100% of the S. aureus strains tested but was undetectable in all of the coagulase-negative staphylococci tested. The possibility of directly detecting the mecA and femA genes in blood samples was also investigated. After two amplification steps, a sensitivity of 50 microorganisms per ml of freshly collected spiked blood was achieved. In conclusion, coamplification of mecA and femA determinants proved to be very reliable both for rapid detection of methicillin resistance and differential diagnosis between S. aureus and other staphylococci. This technique, which can be successfully performed with blood samples, could be a useful tool in the diagnosis and treatment monitoring of staphylococcal infections.

Bacterial Proteins↗

Evaluation of a new identification system, Crystal Enteric/Non-Fermenter, for gram-negative bacilli.

A total of 505 fermentative and 201 nonfermentative gram-negative bacilli, identified by conventional methods, were tested by the Crystal Enteric/Non-Fermenter ID kit and by the API 20E or API 20NE identification system. The overall correct results for fermenters were 92.9% by the Crystal kit and 89.1% by the API 20E system. The false identifications (genus and species incorrect) accounted for 3.1 and 7.1% for the Crystal and API systems, respectively. For nonfermenters, figures for correct identifications by the two systems were comparable (Crystal, 75.9%; API 20NE, 75.3%) while the API 20NE system gave twice as many incorrect results (13.8%) as Crystal (6.3%); however, Crystal failed to precisely identify several species included in a "miscellaneous" group. The Crystal Enteric/Non-Fermenter system is an easy-to-use kit which compares favorably with other commercial systems.

Bacterial Typing Techniques↗