Recurring outbreaks by the same Escherichia coli ST10 clone in a broiler unit during 18 months

The current investigation aimed at characterizing the cause of multiple disease outbreaks in the same broiler production unit during a course of 18 months. The outbreaks had mortality rates of up to 22%. Escherichia coli was diagnosed as the responsible agent. Multiple-locus variable-number tandem-repeat analysis showed that all chicken isolates had identical band patterns. Core genome comparisons demonstrated that the 36 chicken isolates differed with maximum of nine nucleotides indicating that the same E. coli clone was responsible for all seven disease outbreaks despite adherence to the all-in-all production principle and rigorous cleaning and disinfection procedures.

Elastic Wave Propagation in Hierarchical Honeycombs With Woodpile-Like Vertexes

This paper investigates the dispersion behavior of elastic wave propagation in hierarchical honeycombs using the finite element method in conjunction with the Bloch's theorem. The hierarchical honeycomb is constructed by replacing each vertex of a regular hexagonal honeycomb with smaller hexagons stacked in a woodpile pattern. Band structure analysis reveals that, in the considered range of frequency, the maximum band gap for the hierarchical honeycomb is localized in the frequency corresponding to the natural vibration frequency of the cell strut, and moreover, the width of this particular gap is significantly broadened as the order of hierarchy increases. In addition, for the hierarchical honeycombs satisfying an invariable ratio between the thickness and squared length of the cell strut, which is extracted from the expression of the natural frequency of the simply supported element beam, a coincidence among dispersion curves (or contours) for the hierarchical configurations with the same scale order occurs. The resulting identical band gaps as well as the quasi-static phase wave velocities provide an advantage or the hierarchical honeycombs in the manipulation of vibration and associated multifunction designs.

Spatial distribution of genets in population of saprotrophic fungi Marasmius rotula on Mt. Stara planina

This study was conducted to determine the size and spatial distribution of mycelial individuals of Marasmius rotula at one locality on Mt. Stara planina in the Republic of Serbia. Total of 12 sporocarps were collected from investigated locality (Vidlic, Stara planina). Sporocarps were distributed in four groups and distances between them were approximately 10-30 meters. Genomic DNA was extracted from each sporocarp and used for inter-simple sequence repeat (ISSR) polymorphism analysis using (GTG)5 and (GACA)4 primers. Both primers showed reproducible band patterns on agarose gels and sporocarps with identical band patterns were considered to belong to the same individual (genet) and were grouped accordingly. Grouping with both primers determined that 12 analyzed sporocarps belong to 4 distinct genets (A, B, C, D). Approximate genet diameters were 2 m for two genets (A, B) and 15 m for one genet (C) while diameter of one genet (D) was not possible to determine since it was represented only by one sporocarp. The results presented here are the first data about size and spatial distribution of genets of M. rotula. To determine whether the obtained genet sizes are general trait of an analyzed species or a special trait appeared as an effect of environmental conditions, more information on the genet distribution of other M. rotula populations is needed.

Comparison of Mutans Streptococcal Strains of Father, Mother, and Child in Indian Families using Chromosomal Dna Fingerprinting

ABSTRACT Introduction It is now understood and accepted that there is a direct transmission of mutans streptococci (MS) from the mother to the child. There is also a direct correlation between the levels of MS in the mother and the caries status of the child. Advanced technologies in molecular biology like chromosomal DNA fingerprinting have established beyond doubt that the mother and the child bear similar strains of MS. Aim A study was designed with the aim of comparing the MS strains between the father, mother and the child in Indian families. Materials and methods A group of 20 Indian families comprising of the father, mother and child were selected and divided into caries free and caries active groups. Mixed salivary samples were collected from the individuals and were cultured for the growth of Mutans streptococci. The colonies were counted on a colony counter and a comparison was made between the mutans streptococcal counts of the mother and the caries status of the child. Further, the genotypes of the father, mother and the child were isolated and compared using the technique of chromosomal DNA fingerprinting. Following electrophoresis, the band pattern obtained was compared for similarities or differences. The results of the same were tabulated and evaluated statistically Results When the colony counts of the mother (in CFU/ml) were compared with the ‘dft’ status of the child, a positive correlation was seen in group II. Intergroup comparison using the unpaired T test was statistically significant. Electrophoretic analysis of the chromosomal DNA on the agarose gels revealed identical band patterns in 13 mother-child pairs, which was statistically significant. Three of the father-child pairs showed identical band patterns, which was statistically significant. Intergroup comparison using Chi-square test was not statistically significant. Conclusion One may conclude that irrespective of the caries status of the child, majority of the mother child pairs share identical strains of MS and hence the mother is the primary source of infection. However, in children with a high dft, the father may also play an important role in the acquisition and transmission of MS. How to cite this article Katre AN, Damle SG. Comparison of Mutans Streptococcal Strains of Father, Mother, and Child in Indian Families using Chromosomal DNA Fingerprinting. J Contemp Dent Pract 2013;14(5):911-916.

The first Bulgarian allergen extract from Ambrosia artemisiifolia L.

Ambrosia artemisiifolia L. is a leading cause of allergies in many countries. In the last decade it has appeared and spread in Bulgaria as well. The aims of this study was to collect pollen from ragweed plants in Bulgaria, prepare the first Bulgarian ragweed allergen, and characterize it. The new allergen was studied in parallel with two other ragweed pollen extracts from the USA and Russia. The protein profile was studied through isoelectric focusing, and the total allergen activity was studied by a skin prick test and a basophil activation test. The proteins of the studied extracts were concentrated in the pI region 3.5–5.5 with an identical band number and location. The allergens showed similar total allergen activity in vivo:14/81 tested patients (17.3 %) were SPT positive either to a single ragweed extract or to all three. The allergens had identical histogram profiles and caused basophil degranulation above the test cut-off. The analysis of the flow cytometry results by parallel line bioassay shows linear dose-response relation between the extracts. The observed immunological properties of the Bulgarian allergen from Ambrosia artemisiifolia provide a possibility to use this product for a reliable diagnosis and effective specific immunotherapy of ragweed allergy in our country.

Distribution of Campylobacter Genotypes on Broilers during Slaughter

The highly discriminatory genotyping methods now available for Campylobacter have enabled investigation of the diversity, origin, and route of transmission of this organism. In this study, we investigated the frequency of several genotypes of Campylobacter on chicken carcasses postchilling and on neck skin and cloacal swabs taken at slaughter. Campylobacter isolates recovered with and without enrichment from carcasses were subtyped by macrorestriction profiling. Subtyping 199 Campylobacter isolates from 36 carcasses revealed an average of 1.5 genotypes per carcass. The genotypes present on carcasses were, in most cases, also found in the cloacal samples taken at the beginning of the slaughter process. However, genotypes present on carcasses were, in some cases, not found in the corresponding cloacal samples but in cloacal samples of the preceding slaughter group and, in one case, from the preceding day. The genotypes present in cloacal samples were, with one exception, also found on the corresponding carcasses, indicating that most genotypes survive processing. In most cases, there was a difference of several bands between genotypes present in the same slaughter group, indicating different origins of the isolates rather than the occurrence of a recombination event. However, in two cases, a recombination event could have generated the difference in band patterns seen for two pairs of isolates with nearly identical band patterns, even after cleavage with a second restriction enzyme. The results indicate that individual Campylobacter-positive Swedish chicken carcasses, as well as whole carcass groups, are, in general, contaminated by one or two different genotypes.