scholarly journals Characterization and Genetic Diversity of Listeria monocytogenes Isolated from Cattle Abortions in Latvia, 2013–2018

2021 ◽  
Vol 8 (9) ◽  
pp. 195
Author(s):  
Žanete Šteingolde ◽  
Irēna Meistere ◽  
Jeļena Avsejenko ◽  
Juris Ķibilds ◽  
Ieva Bergšpica ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Causative Agent ◽  
Animal Species ◽  
Clonal Complex ◽  
The Third ◽  
Wide Range ◽  
Sequence Types

Listeria monocytogenes can cause disease in humans and in a wide range of animal species, especially in farm ruminants. The aim of the study was to determine the prevalence and genetic diversity of L. monocytogenes related to 1185 cattle abortion cases in Latvia during 2013–2018. The prevalence of L. monocytogenes among cattle abortions was 16.1% (191/1185). The seasonality of L. monocytogenes abortions was observed with significantly higher occurrence (p < 0.01) in spring (March–May). In 61.0% of the cases, the affected cattle were under four years of age. L. monocytogenes abortions were observed during the third (64.6%) and second (33.3%) trimesters of gestation. Overall, 27 different sequence types (ST) were detected, and four of them, ST29 (clonal complex, CC29), ST37 (CC37), ST451 (CC11) and ST7 (CC7), covered more than half of the L. monocytogenes isolates. Key virulence factors like the prfA-dependent virulence cluster and inlA, inlB were observed in all the analyzed isolates, but lntA, inlF, inlJ, vip were associated with individual sequence types. Our results confirmed that L. monocytogenes is the most important causative agent of cattle abortions in Latvia and more than 20 different STs were observed in L. monocytogenes abortions in cattle.

scholarly journals Why and How to Switch to Genomic Selection: Lessons From Plant and Animal Breeding Experience

2021 ◽  
Vol 12 ◽  
Author(s):  
◽  
Aline Fugeray-Scarbel ◽  
Catherine Bastien ◽  
Mathilde Dupont-Nivet ◽  
Stéphane Lemarié
Keyword(s):  
Genetic Diversity ◽  
Genomic Selection ◽  
Plant Species ◽  
Animal Species ◽  
Animal Breeding ◽  
Breeding Cycle ◽  
Breeding Programs ◽  
The Third ◽  
Wide Range ◽  
Selection For

The present study is a transversal analysis of the interest in genomic selection for plant and animal species. It focuses on the arguments that may convince breeders to switch to genomic selection. The arguments are classified into three different “bricks.” The first brick considers the addition of genotyping to improve the accuracy of the prediction of breeding values. The second consists of saving costs and/or shortening the breeding cycle by replacing all or a portion of the phenotyping effort with genotyping. The third concerns population management to improve the choice of parents to either optimize crossbreeding or maintain genetic diversity. We analyse the relevance of these different bricks for a wide range of animal and plant species and sought to explain the differences between species according to their biological specificities and the organization of breeding programs.

scholarly journals MLST Reveals a Separate and Novel Clonal Group for Acidovorax avenae Strains Causing Red Stripe in Sugarcane from Argentina

2019 ◽  
Vol 109 (3) ◽  
pp. 358-365 ◽  
Author(s):  
Paola D. Fontana ◽  
Nicolás Tomasini ◽  
Cecilia A. Fontana ◽  
Valentina Di Pauli ◽  
Pier S. Cocconcelli ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Dna Analysis ◽  
Clonal Complex ◽  
Random Amplified Polymorphic Dna ◽  
Economic Losses ◽  
Best Response ◽  
Wide Range ◽  
Dicotyledonous Plants ◽  
Sequence Types ◽  
Reference Strains

Acidovorax spp. cause a wide range of economically important diseases in monocotyledonous and dicotyledonous plants, including sugarcane, corn, rice, oat, millet, foxtail watermelon, and orchid. In Argentina, the red stripe disease of sugarcane caused by Acidovorax avenae affects 30% of the milling stems with important economic losses. To explore the genetic diversity of this bacterium associated with red stripe in Argentina, multilocus sequence typing (MLST) was applied. This study included 15 local strains isolated from four different sugarcane planting regions and selected after random amplified polymorphic DNA analysis and reference strains of A. citrulli, A. avenae, and A. oryzae to investigate their phylogenetic relationships. MLST analysis resulted in five sequence types among the sugarcane A. avenae strains which constitute a clonal complex, meaning a common and close origin. Sugarcane strains were related to A. avenae from other hosts and distant to A. citrulli. Signals of frequent recombination in several lineages of A. avenae was detected and we observed that A. oryzae is closely related to A. avenae strains. This study provides valuable data in the field of epidemiological and evolutionary investigations of novel clone of A. avenae strains causing sugarcane red stripe. The knowledge of the genetic diversity and strain-host specificity are important to select the genotypes with the best response to the red stripe disease.

scholarly journals Genetic Diversity of Campylobacter jejuni Isolates from Farm Animals and the Farm Environment

2003 ◽  
Vol 69 (12) ◽  
pp. 7409-7413 ◽  
Author(s):  
F. M. Colles ◽  
K. Jones ◽  
R. M. Harding ◽  
M. C. J. Maiden
Keyword(s):  
Genetic Diversity ◽  
Campylobacter Jejuni ◽  
Human Disease ◽  
Clonal Complex ◽  
Food Samples ◽  
Complex Model ◽  
Farm Animals ◽  
Significant Genetic Differentiation ◽  
Sequence Types ◽  
Retail Food

ABSTRACT The genetic diversity of Campylobacter jejuni isolates from farm animals and their environment was investigated by multilocus sequence typing (MLST). A total of 30 genotypes, defined by allelic profiles (assigned to sequence types [STs]), were found in 112 C. jejuni isolates originating in poultry, cattle, sheep, starlings, and slurry. All but two of these genotypes belonged to one of nine C. jejuni clonal complexes previously identified in isolates from human disease and retail food samples and one clonal complex previously associated with an environmental source. There was some evidence for the association of certain clonal complexes with particular farm animals: isolates belonging to the ST-45 complex predominated among poultry isolates but were absent among sheep isolates, while isolates belonging to the ST-61 and ST-42 complexes were predominant among sheep isolates but were absent from the poultry isolates. In contrast, ST-21 complex isolates were distributed among the different isolation sources. Comparison with MLST data from 91 human disease isolates showed small but significant genetic differentiation between the farm and human isolates; however, representatives of six clonal complexes were found in both samples. These data demonstrate that MLST and the clonal complex model can be used to identify and compare the genotypes of C. jejuni isolates from farm animals and the environment with those from retail food and human disease.

scholarly journals Clonal analysis of the serogroup B meningococci causing New Zealand's epidemic

2005 ◽  
Vol 134 (2) ◽  
pp. 377-383 ◽  
Author(s):  
K. H. DYET ◽  
D. R. MARTIN
Keyword(s):  
Genetic Diversity ◽  
New Zealand ◽  
16S Rrna ◽  
Meningococcal Disease ◽  
Common Ancestor ◽  
Clonal Complex ◽  
Clonal Analysis ◽  
The Other ◽  
Disease Rates ◽  
Sequence Types

An epidemic of meningococcal disease caused by serogroup B meningococci expressing the P1.7-2,4 PorA protein began in New Zealand in 1991. The PorA type has remained stable. Different porB have been found in association with the P1.7-2,4 PorA, although type 4 has been most common. The clonal origins of B:P1.7-2,4 meningococci isolated from cases during 1990 to the end of 2003 were analysed. In 1990, the year immediately preceding the recognized increase in disease rates, all three subclones (ST-41, ST-42, and ST-154) of the ST-41/44 clonal complex occurred among the five isolates of B:P1.7-2,4. The two sequence types, ST-42 and ST-154, continued to cause most disease throughout New Zealand. Isolates belonging to subclone ST-41 were mostly identified early in the epidemic and in the South Island. 16S rRNA typing indicated that isolates belonging to the subclones ST-41 and ST-154 share a common ancestor, with those typing as ST-42 more distantly related with some genetically ambiguous. It is possible that ST-41 and ST-154 may have evolved one from the other but evolution to ST-42 is more difficult to explain. It is possible that one or more of the ST types could have been introduced into New Zealand prior to the first detection of clinical cases in 1990. Genetic diversity may have occurred during carriage in the community.

Structure and function of the important internalins of Listeria monocytogenes

2021 ◽  
Vol 22 ◽  
Author(s):  
Shabir Ahmad Mir
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Causative Agent ◽  
Structure And Function ◽  
Intracellular Bacterium ◽  
Infection Cycle ◽  
Current Review ◽  
Functional Aspects ◽  
Structural Details ◽  
And Function

: Listeria monocytogenes, a facultative intracellular gram-positive pathogen, is the causative agent of the disease listeriosis. The virulence of this intracellular bacterium is dependent on the coordinated activity of various bacterial factors, which are in turn tightly controlled by a specific set of regulators. The arsenal of virulence factors employed by L. monocytogenes for its infection cycle is available in the literature. Although the internalins of L. monocytogenes have been studied in detail their structural details are currently scattered and fragmented. Therefore, in the current review, we provide a brief account of the existing knowledge on structural details of the key internalins of L. monocytogenes and also highlight the recent advances in their functional aspects.

scholarly journals High Genetic Diversity in Flavobacterium psychrophilum Isolates from Healthy Rainbow Trout (Oncorhynchus mykiss) Farmed in the Same Watershed, Revealed by Two Typing Methods

2020 ◽  
Vol 87 (2) ◽  
Author(s):  
Ségolène Calvez ◽  
Nora Navarro-Gonzalez ◽  
Charlène Siekoula-Nguedia ◽  
Catherine Fournel ◽  
Eric Duchaud
Keyword(s):  
Genetic Diversity ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Clonal Complex ◽  
Economic Losses ◽  
High Genetic Diversity ◽  
Content Type ◽  
Flavobacterium Psychrophilum ◽  
Sequence Types ◽  
Apparently Healthy

ABSTRACT Flavobacterium psychrophilum affects salmonid health worldwide and causes economic losses. The genetic diversity of the pathogen must be considered to develop control methods. However, previous studies have reported both high and low levels of genetic diversity. The present longitudinal study aimed at assessing the genetic diversity of F. psychrophilum at a small temporal and geographic scale. Four farms located on the same watershed in France were studied. Rainbow trout (Oncorhynchus mykiss) batches were monitored, and apparently healthy individuals were sampled over 1 year. A total of 288 isolates were recovered from fish organs (gills and spleen) and eggs. Pulsed field gel electrophoresis revealed high genetic diversity. Multilocus sequence typing performed on a selection of 31 isolates provided congruent results, as follows: 18 sequence types (STs) were found, of which 13 were novel. The mean gene diversity (H = 0.8413) was much higher than that previously reported for this host species, although the sampling was restricted to a single watershed and 1 year. Seven isolates out of 31 were assigned to clonal complex ST10 (CC-ST10), which is the predominant clonal complex in the main salmonid production areas. A split decomposition tree reflected a panmictic population. This finding is important for aquaculture veterinarians in their diagnostic procedure, as the choice of adequate antibiotic treatment is conditioned by the correct identification of the causative agent. Furthermore, this study expands our knowledge on genetic diversity required for the development of an effective vaccine against F. psychrophilum. IMPORTANCE The bacterium Flavobacterium psychrophilum is a serious pathogen in many fish species, especially salmonids, that is responsible for considerable economic losses worldwide. In order to treat infections and to develop vaccines, the genetic diversity of this bacterium needs to be known. We assessed the genetic diversity of F. psychrophilum isolates from apparently healthy rainbow trout raised in several fish farms in the same watershed in France. Two different genotyping methods revealed high diversity. The majority of isolates were unrelated to clonal complex sequence type 10 (CC-ST10), the clonal complex that is predominant worldwide and associated with disease in rainbow trout. In addition, we found 13 novel sequence types. These results suggest that a diverse subpopulation of F. psychrophilum may be harbored by rainbow trout.

scholarly journals Occurrence and molecular characteristics of Listeria monocytogenes isolated from ready-to-eat meats in Hanoi, Vietnam

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Thuy Phung ◽  
Tung Tran ◽  
Dung Pham ◽  
Anh To ◽  
Hoa Le
Keyword(s):  
Genetic Diversity ◽  
Listeria Monocytogenes ◽  
Spanning Tree ◽  
Minimum Spanning Tree ◽  
Meat Products ◽  
Control Measures ◽  
Molecular Characteristics ◽  
Meat Samples ◽  
And Control ◽  
Sequence Types

Listeria monocytogenes represents one of the most serious threats to food safety. Several studies have shown that Ready-To- Eat (RTE) meats are an important vehicle responsible for listeriosis in human. In Vietnam, little is known about the occurrence and molecular characteristics of L. monocytogenes in meat products, which are essential for developing monitoring plans and control measures. In the present study, we investigated the occurrence of L. monocytogenes in 258 sausage and sliced meat samples collected during the period of 2013-2015 and determined the genetic diversity of the isolates using multi-locus sequence typing (MLST). Overall, L. monocytogenes was present in 19/129 (14.7 %) and 40/129 (31.0 %) sausage and sliced meat samples respectively, with the peak of occurrence being in summer. Furthermore, a minimum spanning tree was constructed based on MLST data of 47 isolates. A total of 15 sequence types were found, with five being novel. Notably, the majority of the isolates (34/47) belonged to the hypervirulent clonal complexes 1, 2, and 3.

scholarly journals Virulence factors of Actinobacillus actinomycetemcomitans: other putative factors

2000 ◽  
Vol 14 (1) ◽  
pp. 05-11
Author(s):  
Mario Julio AVILA-CAMPOS ◽  
Maria Regina Lorenzetti SIMIONATO ◽  
Silvana CAI ◽  
Márcia Pinto Alves MAYER ◽  
José Luiz DE LORENZO ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Periodontal Disease ◽  
Virulence Factors ◽  
Causative Agent ◽  
Tissue Repair ◽  
Bacteriocin Production ◽  
Actinobacillus Actinomycetemcomitans ◽  
Blood Types ◽  
Wide Range ◽  
Localized Juvenile Periodontitis

Actinobacillus actinomycetemcomitans is implicated as the causative agent of localized juvenile periodontitis. This organism possesses a large number of virulence factors with a wide range of activities and also interfere with tissue repair. Fifty isolates of A. actinomycetemcomitans from 20 periodontal patients were examined to evaluate other putative virulence factors. In this study, the capsule, DNase, coagulase, fibrinolysin, proteolytic, haemolysin and bacteriocin production, haemagglutination, serum sensitivity, epithelial cells attachment, hydrophobicity and virulence of the A. actinomycetemcomitans isolates were evaluated. All the isolates were resistant to the different tested sera. 70% to 94% were alpha-haemolytics and agglutinated all blood types. Most of isolates produced antagonistic substances and they had a low hydrophobicity. None of the isolates was pathogenic for mice. Little is known as to wether these factors may act in the development of periodontal disease, and further studies are required for an application in pathogenic and systematic terms.

scholarly journals Wide Distribution of Virulence Genes amongEnterococcus faeciumandEnterococcus faecalisClinical Isolates

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sara Soheili ◽  
Sobhan Ghafourian ◽  
Zamberi Sekawi ◽  
Vasanthakumari Neela ◽  
Nourkhoda Sadeghifard ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Virulence Genes ◽  
Wide Distribution ◽  
Clinical Isolates ◽  
Nosocomial Pathogen ◽  
High Concentration ◽  
The Third ◽  
Wide Range ◽  
Facultative Anaerobic ◽  
Enterococcal Species

Enterococcus, a Gram-positive facultative anaerobic cocci belonging to the lactic acid bacteria of the phylum Firmicutes, is known to be able to resist a wide range of hostile conditions such as different pH levels, high concentration of NaCl (6.5%), and the extended temperatures between 5°C and 65°C. Despite being the third most common nosocomial pathogen, our understanding on its virulence factors is still poorly understood. The current study was aimed to determine the prevalence of different virulence genes inEnterococcus faecalisandEnterococcus faecium. For this purpose, 79 clinical isolates of Malaysian enterococci were evaluated for the presence of virulence genes.pilB, fms8, efaAfm, andsgrAgenes are prevalent in all clinical isolates. In conclusion, the pathogenicity ofE. faecalisandE. faeciumcould be associated with different virulence factors and these genes are widely distributed among the enterococcal species.

Identification and proposal of a potentially new clonal complex that is a common cause of MenB disease in central and eastern Canada

2012 ◽  
Vol 58 (10) ◽  
pp. 1236-1240 ◽  
Author(s):  
Raymond S.W. Tsang ◽  
Brigitte Lefebvre ◽  
Frances B. Jamieson ◽  
Rodica Gilca ◽  
Shelley L. Deeks ◽  
...  
Keyword(s):  
Clonal Complex ◽  
Present Finding ◽  
Variable Region ◽  
The Other ◽  
Eastern Canada ◽  
Common Cause ◽  
The Third ◽  
Common Causes ◽  
Canadian Provinces ◽  
Sequence Types

This study examined serogroup B meningococci (MenB) from invasive meningococcal disease (IMD) cases in the provinces of Québec and Ontario in the last decade by multilocus sequence typing (MLST) to determine their sequence types (STs) and clonal complexes (CCs). Forty isolates from individual MenB IMD cases were found to belong to 8 related STs, with ST-336 being the founding ST and the other 7 STs being single locus variants of ST-336. Eleven isolates belonged to ST-336, 23 belonged to ST-5571, and the other 6 were represented individually by a single different ST. All but 1 of these 40 isolates have the PorA variable-region type of P1.22,14,36. Interrogation of the Neisseria MLST web site with the present finding did not put any of the 8 related STs into known CCs. Since these 8 related STs were common causes of IMD, with ST-5571 being the most frequently identified ST in Ontario and ST-336 the third most common ST identified in Québec, we propose that ST-336 and its related STs is a potentially new meningococcal clonal complex that is endemic in the Canadian provinces of Québec and Ontario, and they constitute a common cause of IMD.

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