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Epidemiologically Related (epidemiologically + relate)
Selected AbstractsGenetic variations among Mycoplasma bovis strains isolated from Danish cattleFEMS MICROBIOLOGY LETTERS, Issue 1 2000Lughano J.M. Kusiluka Abstract The genetic heterogeneity of Mycoplasma bovis strains isolated in Denmark over a 17-year period was investigated. Forty-two field strains isolated from different geographic locations and specimens, including strains from 21 herds involved in two outbreaks of M. bovis -induced mastitis, and the type strain of M. bovis (PG45T) were assayed for variations in the BglII and MfeI restriction sites in the chromosomal DNA by using the amplified fragment length polymorphism (AFLP) fingerprinting technique. The obtained genomic fingerprints consisted of 62,68 AFLP fragments in the size range of 50,500 bp. Among the analyzed strains, 18 different AFLP profiles were detected. The similarity between individual fingerprints, calculated by Dice similarity coefficient, ranged from 0.9 to 1.0. Twenty-five strains, including 23 which were isolated during two outbreaks of M. bovis -induced mastitis which occurred 2 years apart, showed indistinguishable AFLP patterns. More genetic diversity was observed among the recent strains. The similarity of the genotypes of the field strains to that of the M. bovis type strain (PG45T) was 97.7%. The results of this study have demonstrated a remarkable genomic homogeneity of Danish strains of M. bovis that were probably epidemiologically related and which have remained stable for a considerable length of time. Furthermore, this study has demonstrated that AFLP can be used for genomic fingerprinting and discrimination of M. bovis strains. [source] Comparison of Salmonella enterica serotype Infantis isolates from a veterinary teaching hospitalJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007M. Dunowska Abstract Aims:, To compare Salmonella enterica serotype Infantis isolates obtained from patients or the environment of a veterinary teaching hospital over a period of 9 years following a nosocomial outbreak to determine whether isolates were epidemiologically related or represented unrelated introductions into the hospital environment. Methods and Results:, Fifty-six S. Infantis isolates were compared based on their phenotypic (antimicrobial drug [AMD] susceptibility pattern) and genotypic (pulsed-field gel electrophoresis [PFGE] pattern and presence of integrons) characteristics. Epidemiologically unrelated S. Infantis isolates clustered separately from all but two of the hospital isolates, and several isolates from different years and various sources were indistinguishable from each other in cluster analysis of two-enzyme PFGE results. A high percentage of isolates (80·3%) were resistant to at least one AMD, with 67·8% showing resistance to >5 AMD. The majority (74·1%) of isolates tested contained type 1 integrons. Conclusion:, Results strongly suggest that there was nosocomial transmission of S. Infantis during the initial outbreak, and that contamination arising from this outbreak persisted across years despite rigorous hygiene and biosecurity precautions and may have led to subsequent nosocomial infections. Significance and Impact of the Study:, Evidence of persistence and transmission of Salmonella clones across years, even in the face of rigorous preventive measures, has important implications for other facilities that have experienced outbreaks of Salmonella infections. [source] High prevalence of carbapenem-hydrolysing oxacillinases in epidemiologically related and unrelated Acinetobacter baumannii clinical isolates in SpainCLINICAL MICROBIOLOGY AND INFECTION, Issue 12 2007M. Ruiz Abstract Carbapenem-hydrolysing oxacillinases are reported increasingly in Acinetobacter baumannii. This study investigated the role of these ,-lactamases in causing resistance to carbapenems in 83 epidemiologically related and unrelated imipenem-resistant A. baumannii clinical isolates. The isolates were also analysed for the presence of ISAba1 in the promoter region of the blaOXA-51 -like gene in order to investigate the role of ISAba1 in OXA-51 expression. All clinical isolates contained a blaOXA-51 -like gene, 20% contained a blaOXA-58 -like gene, and 42% contained a blaOXA-40 -like gene; blaOXA-23 -like, blaIMP and blaVIM genes were not detected in any of the isolates investigated. ISAba1 was found in 24 (82.7%) of 28 pulsetypes, and was located in the promoter region of the blaOXA-51 -like gene in five (20.8%) of these pulsetypes. Expression of blaOXA-51 was detected in the five isolates with ISAba1 located in the promoter region, but was not detected in an isogenic imipenem-susceptible A. baumannii isolate that did not have ISAba1 located in the promoter region. It was concluded that there is a high prevalence of oxacillinases with activity against carbapenems among genetically unrelated A. baumannii clinical isolates from Spain, and that concomitant expression of two carbapenemases (OXA-51-like and either OXA-40-like or OXA-58-like) may take place. Insertion of an ISAba1 -like element in the promoter of the blaOXA-51 -like gene promotes the expression of this gene, although this did not seem to play a major role in carbapenem resistance. [source] | ||||||||||