scholarly journals GENETIC DIVERSITY OF MYCOBACTERIUM AVIUM subsp. HOMINISSUIS STRAINS ISOLATED IN ITALY BASED ON VNTR LOCI ANALYSIS

2019 ◽  
Vol 8 (4) ◽  
pp. 441-446
Author(s):  
M. Menichini ◽  
F. Genua ◽  
N. Lari ◽  
L. Rindi

Abstract.Background.Mycobacterium avium subsp. hominissuis (MAH) is an important pathogen responsible for most of the human-associated nontuberculous mycobacteria infections. Over the past few decades the incidence of MAH infections is increasing in Italy, as in many countries worldwide. The present study is aimed to elucidate the genetic characteristics of MAH strains isolated from human patients using VNTR typing and to show the genetic relatedness among them.Methods.The genetic diversity of 108 human isolates of MAH was determined by VNTR analysis targeting 8 loci, coded 32, 292, X3, 25, 3, 7, 10 and 47.Results.The VNTR analysis revealed 25 distinct VNTR patterns; of these, 13 patterns were unique, while 12 patterns were shared by 2 or more isolates, thus yielding 12 clusters including a total of 95 isolates. The discriminatory power of our VNTR analysis yielded an HGDI of 0.990, indicating that VNTR typing has an excellent discriminatory power. No association of a particular VNTR pattern with a particular clinical feature, such as the disseminated, pulmonary or extrapulmonary type of infection, was observed. Minimum spanning tree analysis showed that 21 VNTR patterns, occurring either as clustered or unique isolates, differed from the nearest one for one allelic variation.Conclusions.The results obtained through the VNTR analysis showed that most MAH strains displayed a close genetic relationship. This high phylogenetic proximity of the VNTR loci over a long time period supports the concept that the MAH genotype is highly homogeneous in our geographical area, suggesting the hypothesis of the presence of possible sources of infection and transmission pathways at the local level.

2012 ◽  
Vol 12 (4) ◽  
pp. 846-852 ◽  
Author(s):  
Tomotada Iwamoto ◽  
Chie Nakajima ◽  
Yukiko Nishiuchi ◽  
Tomoko Kato ◽  
Shiomi Yoshida ◽  
...  

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Nicoletta Lari ◽  
Laura Rindi

Abstract Background M. intracellulare is a frequent causative pathogen of nontuberculous mycobacteria infection that causes infections in the respiratory tract, whose incidence is increasing in many countries. This study aimed at determining the VNTR-based genetic diversity of a collection of 39 M. intracellulare human strains isolated from respiratory specimens over the last 5 years. Results The VNTR analysis showed that M. intracellulare strains displayed a high genetic diversity, indicating that the M. intracellulare genotypes are quite heterogeneous in our geographical area. Moreover, a comparison with VNTR profiles of strains from other countries confirmed that genotypes of clinical strains of M. intracellulare are not related to geographical origin. Conclusions VNTR typing has proved to be a highly discriminatory method for better understanding the molecular epidemiology of M. intracellulare.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.


2012 ◽  
Vol 48 (No. 1) ◽  
pp. 23-32 ◽  
Author(s):  
I. Bellil ◽  
M. Chekara Bouziani ◽  
D. Khelifi

Saharan wheats have been studied particularly from a botanical viewpoint. Genotypic identification, classification and genetic diversity studies to date were essentially based on the morphology of the spike and grain. For this, the allelic variation at the glutenin loci was studied in a set of Saharan bread and durum wheats from Algerian oases where this crop has been traditionally cultivated. The high molecular weight and low molecular weight glutenin subunit composition of 40 Saharan bread and 30 durum wheats was determined by SDS-PAGE. In Saharan bread wheats 32 alleles at the six glutenin loci were detected, which in combination resulted in 36 different patterns including 17 for HMW and 23 for LMW glutenin subunits. For the Saharan durum wheats, 29 different alleles were identified for the five glutenin loci studied. Altogether, 29 glutenin patterns were detected, including 13 for HMW-GS and 20 for LMW-GS. Three new alleles were found in Saharan wheats, two in durum wheat at the Glu-B1 and Glu-B3 loci, and one in bread wheat at the Glu-B1 locus. The mean indices of genetic variation at the six loci in bread wheat and at the five loci in durum wheat were 0.59 and 0.63, respectively, showing that Saharan wheats were more diverse. This information could be useful to select Saharan varieties with improved quality and also as a source of genes to develop new lines when breeding for quality.


Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20
Author(s):  
Luigi De Grossi ◽  
Davide Santori ◽  
Antonino Barone ◽  
Silvia Abbruzzese ◽  
Matteo Ricchi ◽  
...  

Paratuberculosis is a chronic disease of ruminants caused by Mycobacterium avium subsp. Paratuberculosis (MAP). Since isolation of MAP type I (S) is rarely reported in Italy, our research was aimed at isolating, by an inexpensive liquid culture manual method, this type of MAP isolates. At first, we used an ELISA to point out to serologically positive samples from five flocks. Secondly, we used a fecal direct IS900-qPCR on the ELISA positive samples, in order to detect shedder animals. Feces from IS900-qPCR positive samples were inoculated in solid and liquid culture media. IS900-qPCR was further used to test the growth of MAP isolates in liquid medium, which were further confirmed by f57-qPCR and submitted to typing by specific PCR in order to identify the MAP type. Twenty-eight samples (24 fecal and four tissutal samples) were processed by culture methods, resulting in the isolation of six type I MAP field isolates. Notably, no isolates were recovered by solid media, underlining the utility of this liquid method. Few data about this type of MAP are currently available in Italy, and further analyses should be carried out in order to study the origin and epidemiology of type I strains circulating in Italy.


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