scholarly journals Predominance of Distinct Listeria Innocua and Listeria Monocytogenes in Recurrent Contamination Events at Dairy Processing Facilities

2020 ◽  
Vol 8 (2) ◽  
pp. 234 ◽  
Author(s):  
Irene Kaszoni-Rückerl ◽  
Azra Mustedanagic ◽  
Sonja Muri-Klinger ◽  
Katharina Brugger ◽  
Karl-Heinz Wagner ◽  
...  
Keyword(s):  
Restriction Enzymes ◽  
Housekeeping Genes ◽  
Sensu Stricto ◽  
Genetic Lineage ◽  
Selective Enrichment ◽  
Pfge Typing ◽  
Dairy Processing ◽  
Associated Species ◽  
Adaptive Nature ◽  
Contamination Events

The genus Listeria now comprises up to now 21 recognized species and six subspecies, with L. monocytogenes and L. innocua as the most prevalent sensu stricto associated species. Reports focusing on the challenges in Listeria detection and confirmation are available, especially from food-associated environmental samples. L. innocua is more prevalent in the food processing environment (FPE) than L. monocytogenes and has been shown to have a growth advantage in selective enrichment and agar media. Until now, the adaptive nature of L. innocua in FPEs has not been fully elucidated and potential persistence in the FPE has not been observed. Therefore, the aim of this study is to characterize L. innocua (n = 139) and L. monocytogenes (n = 81) isolated from FPEs and cheese products collected at five dairy processing facilities (A–E) at geno- and phenotypic levels. Biochemical profiling was conducted for all L. monocytogenes and the majority of L. innocua (n = 124) isolates and included a rhamnose positive reaction. L. monocytogenes isolates were most frequently confirmed as PCR-serogroups 1/2a, 3a (95%). Pulsed-field gel electrophoresis (PFGE)-typing, applying the restriction enzymes AscI, revealed 33 distinct Listeria PFGE profiles with a Simpson’s Index of Diversity of 0.75. Multi-locus sequence typing (MLST) resulted in 27 STs with seven new L. innocua local STs (ST1595 to ST1601). L. innocua ST1597 and ST603 and L. monocytogenes ST121 and ST14 were the most abundant genotypes in dairy processing facilities A–E over time. Either SSI-1 (ST14) or SSI-2 (ST121, all L. innocua) were present in successfully FPE-adapted strains. We identified housekeeping genes common in Listeria isolates and L. monocytogenes genetic lineage III. Wherever there are long-term contamination events of L. monocytogenes and other Listeria species, subtyping methods are helpful tools to identify niches of high risk.

scholarly journals Comparative phylogenies of the housekeeping genes atpD, infB and rpoB and the 16S rRNA gene within the Pasteurellaceae

2004 ◽  
Vol 54 (5) ◽  
pp. 1601-1609 ◽  
Author(s):  
Henrik Christensen ◽  
Peter Kuhnert ◽  
John Elmerdahl Olsen ◽  
Magne Bisgaard
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Sensu Stricto ◽  
Rrna Gene ◽  
Ratio Test ◽  
Sequence Comparisons ◽  
The Individual ◽  
The 16S Rrna Gene

Phylogenies of housekeeping gene and 16S rRNA gene sequences were compared to improve the classification of the bacterial family Pasteurellaceae and knowledge of the evolutionary relationships of its members. Deduced partial protein sequences of the housekeeping genes atpD, infB and rpoB were compared in 28, 36 and 28 representative taxa of the Pasteurellaceae, respectively. The monophyly of representatives of the genus Gallibacterium was recognized by analysis of all housekeeping genes, while members of Mannheimia, Actinobacillus sensu stricto and the core group of Pasteurella sensu stricto formed monophyletic groups with two out of three housekeeping genes. Representatives of Mannheimia, Actinobacillus sensu stricto, [Haemophilus] ducreyi and [Pasteurella] trehalosi formed a monophyletic unit by analysis of all three housekeeping genes, which was in contrast to the 16S rRNA gene-derived phylogeny, where these taxa occurred at separate positions in the phylogenetic tree. Representatives of the Rodent, Avian and Aphrophilus–Haemophilus 16S rRNA gene groups were weakly supported by phylogenetic analysis of housekeeping genes. Phylogenies derived by comparison of the housekeeping genes diverged significantly from the 16S rRNA gene-derived phylogeny as evaluated by the likelihood ratio test. A low degree of congruence was also observed between the individual housekeeping gene-derived phylogenies. Estimates on speciation derived from 16S rRNA and housekeeping gene sequence comparisons resulted in quite different evolutionary scenarios for members of the Pasteurellaceae. The phylogeny based on the housekeeping genes supported observed host associations between Mannheimia, Actinobacillus sensu stricto and [Pasteurella] trehalosi and animals with paired hooves.

scholarly journals Borrelia yangtzensis sp. nov., a rodent-associated species in Asia, is related to Borrelia valaisiana

2015 ◽  
Vol 65 (Pt_11) ◽  
pp. 3836-3840 ◽  
Author(s):  
Gabriele Margos ◽  
Chen-Yi Chu ◽  
Ai Takano ◽  
Bao-Gui Jiang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Related Species ◽  
Type Strain ◽  
Strong Support ◽  
Housekeeping Genes ◽  
Species Status ◽  
Closely Related Species ◽  
Typing System ◽  
China And Japan ◽  
Associated Species

Twenty-nine isolates of Lyme borreliosis (LB) group spirochaetes collected from ticks and rodents in China and Japan were included in a multilocus sequence analysis (MLSA). Using a different typing system, three of these strains had previously been identified as being divergent from other LB spirochaete species and the name ‘Borrelia yangtze’ sp. nov. was proposed. The data presented here confirm that the genetic distance, calculated using sequences of MLSA housekeeping genes, to other known LB group spirochaete species was < 95 % and to Borrelia valaisiana was 96.67 % (which represents the most closely related species within the group of LB spirochaetes). This and the fact that these strains are ecologically distinct from B. valaisiana (rodent-transmitted vs bird-transmitted) provide strong support for the validation of the proposed species status. We suggest the name Borrelia yangtzensis sp. nov. The type strain is Okinawa-CW62T ( = DSM 24625T = JCM 17189T).

Monitoring Transmission Routes of Listeria spp. in Smoked Salmon Production with Repetitive Element Sequence-Based PCR Techniques

2012 ◽  
Vol 75 (3) ◽  
pp. 504-511 ◽  
Author(s):  
M. ZUNABOVIC ◽  
K. J. DOMIG ◽  
I. PICHLER ◽  
W. KNEIFEL
Keyword(s):  
Cluster Analysis ◽  
Repetitive Element ◽  
Diversity Index ◽  
Low Cost ◽  
Restriction Enzymes ◽  
Discrimination Power ◽  
Pfge Typing ◽  
Listeria Species ◽  
Smoked Salmon ◽  
Element Sequence

Various techniques have been used for tracing the transmission routes of Listeria species and for the assessment of hygiene standards in food processing plants. The potential of repetitive element sequence-based PCR (Rep-PCR) methods (GTG5 and REPI+II) for the typing of Listeria isolates (n = 116), including Listeria monocytogenes (n = 46), was evaluated in a particular situation arising from the relocation of a company producing cold-smoked salmon. Pulsed-field gel electrophoresis (PFGE) using three restriction enzymes (ApaI, AscI, and SmaI) was used for comparison. Identical transmission scenarios among two companies could be identified by cluster analysis of L. monocytogenes isolates that were indistinguishable by both Rep-PCR and PFGE. The calculated diversity index (DI) indicates that Rep-PCR subtyping of Listeria species with primer sets GTG5 and REPI+II has a lower discrimination power than does PFGE. When concatenated Rep-PCR cluster analysis was used, the DI increased from 0.934 (REPI+II) and 0.923 (GTG5) to 0.956. The discrimination power of this method was similar to that of PFGE typing based on restriction enzyme ApaI (DI = 0.955). Listeria welshimeri may be useful as an indicator for monitoring smoked salmon processing environments. Rep-PCR meets the expectations of a reasonable, fast, and low-cost molecular subtyping method for the routine monitoring of Listeria species. The discriminatory power as characterized by the DI sufficiently quantifies the probability of unrelated isolates being characterized as different subtypes. Therefore, Rep-PCR typing based on two primer systems (GTG5 and REPI+II) may be a useful tool for monitoring industrial hygiene.

Palaearctic oak gallwasps galling oaks (Quercus) in the section Cerris: re-appraisal of generic limits, with descriptions of new genera and species (Hymenoptera: Cynipidae: Cynipini)

Zootaxa ◽  
2010 ◽  
Vol 2470 (1) ◽  
pp. 1 ◽  
Author(s):  
GEORGE MELIKA ◽  
JULI PUJADE-VILLAR ◽  
YOSHIHISA ABE ◽  
CHANG-TI TANG ◽  
JAMES NICHOLLS ◽  
...  
Keyword(s):  
New Species ◽  
New Genus ◽  
Sensu Stricto ◽  
New Genera ◽  
Genus Level ◽  
Phylogenetic Reconstructions ◽  
Associated Species

We discuss the taxonomy of oak gallwasps (Hymenoptera: Cynipidae: Cynipini) whose lifecycle involves only Palaearctic oaks (Quercus subgen. Quercus) in the section Cerris. Recent phylogenetic reconstructions support a deep split between such Cerris-associated species in the genera Aphelonyx, Dryocosmus, Plagiotrochus, Neuroterus, Pseudoneuroterus and species and genera associated with oaks in the section Quercus sensu stricto. We reappraise the generic limits of the Cerris-associated genera, proposing new limits for Dryocosmus, Pseudoneuroterus and Neuroterus, establishing a new genus Cerroneuroterus, elevating Latuspina to a genus level, reestablishing the genera Chilaspis and Trichagalma and proposed new species name combinations. We provide a new key to oak gallwasp genera of the Palaearctic and keys to all species of genera associated with Cerris section oaks. We describe five new species, Aphelonyx kordestanica, Trichagalma formosana, Dryocosmus jungalii, Pseudoneuroterus mazandarani, and P. nichollsi.

Genetic variation in the Sicista subtilis (Pallas, 1773) species group (Rodentia, Sminthidae), as compared to karyotype differentiation

Mammalia ◽  
2020 ◽  
Vol 84 (2) ◽  
pp. 185-194
Author(s):  
Vladimir Lebedev ◽  
Natalia Poplavskaya ◽  
Anna Bannikova ◽  
Mikhail Rusin ◽  
Alexey Surov ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Data ◽  
Chromosomal Evolution ◽  
Sensu Stricto ◽  
Species Group ◽  
Genetic Lineage ◽  
North Caucasus ◽  
Speciation Rate ◽  
Mitochondrial Markers ◽  
The North

AbstractGenetic variation in chromosomally polymorphic Sicista subtilis complex and related Sicista betulina species group was analysed using two mitochondrial markers (COI and Cytb). The S. subtilis group is shown to include six lineages, five of which correspond to species currently recognized based on cytogenetic and genetic data: Sicista nordmanni, Sicista trizona, S. subtilissensu stricto, Sicista severtzovi and Sicista cimlanica. A previously unknown genetic lineage of S. subtilis was found in the North Caucasus. The existence of two divergent lineages within Sicista strandi is supported. It is suggested that the speciation rate in Sicista was strongly affected by rapid chromosomal evolution.

Is Hydroides brachyacantha (Serpulidae : Annelida) a widespread species?

2016 ◽  
Vol 30 (1) ◽  
pp. 41 ◽  
Author(s):  
Yanan Sun ◽  
Eunice Wong ◽  
María Ana Tovar-Hernández ◽  
Jane E. Williamson ◽  
Elena K. Kupriyanova
Keyword(s):  
Gulf Of California ◽  
Phylogenetic Analyses ◽  
South Australia ◽  
Distinct Species ◽  
Molecular Data ◽  
Sensu Stricto ◽  
Type Locality ◽  
Genetic Lineage ◽  
Widespread Species ◽  
Mexican Pacific

Hydroides brachyacantha Rioja, 1941, an important fouling serpulid species originally described from Mazatlán (Southern Gulf of California, Mexico) and Acapulco (southern Mexican Pacific), has been reported from the Mexican Pacific and numerous tropical and subtropical localities. However, a recent description of H. amri Sun, Wong, ten Hove, Hutchings, Williamson & Kupriyanova, 2015 from Australia, which was historically misidentified as H. brachyacantha, suggested that the widespread ‘H. brachyacantha’ is indeed a species complex. To test the status of H. amri, we conducted phylogenetic analyses based on a combined dataset of 18S rRNA, internal transcribed spacer-2, and cytochrome b sequences of H. brachyacantha from the type locality in Mexico with those of H. amri from Australia. Our molecular data supported the morphology-based hypothesis of H. amri and H. brachyacantha sensu stricto as two distinct species. Furthermore, H. amri comprises two non-sister well-supported clades. Hydroides amri thus comprises what we consider two cryptic species with long-term isolation. Here we describe the genetic lineage in South Australia as Hydroides nikae, sp. nov. Given the absence of a holotype of H. brachyacantha, we designate a neotype collected from the type locality (Mazatlán, Mexico). This study calls for a worldwide revision of the H. brachyacantha-complex.

scholarly journals Typing of Listeria monocytogenes Isolates Originating from the Food Processing Industry with Automated Ribotyping and Pulsed-Field Gel Electrophoresis

2003 ◽  
Vol 66 (2) ◽  
pp. 249-255 ◽  
Author(s):  
KAARINA AARNISALO ◽  
TIINA AUTIO ◽  
ANNA-MAIJA SJÖBERG ◽  
JANNE LUNDÉN ◽  
HANNU KORKEALA ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Gel Electrophoresis ◽  
Restriction Enzymes ◽  
Pulsed Field Gel Electrophoresis ◽  
Food Plants ◽  
Discrimination Power ◽  
Pulsed Field ◽  
Pfge Typing ◽  
Automated Ribotyping

A total of 486 Listeria monocytogenes isolates originating from 17 Finnish food processing plants (representing meat, poultry, fish, and dairy production) were collected and typed by automated ribotyping using EcoRI as the restriction enzyme. The isolates were divided into 16 different ribotypes (RTs). Some of these isolates (121), representing all EcoRI types and 16 food plants, were subjected to ribotyping with the PvuII enzyme, to pulsed-field gel electrophoresis (PFGE) typing with AscI and SmaI restriction enzymes, and to serotyping with O-antigen antisera. Nineteen ribotypes were generated with PvuII, 42 macrorestriction patterns were generated with AscI and 24 with SmaI, and three serotypes were generated with antisera. When the results were combined, the overall number of RTs was 23, and that of the PFGE types was 46. Thus, the overall discrimination power of PFGE was higher (discrimination index [DI] 0.966) than that of ribotyping (DI 0.906). The most common serotype (90.1% of the isolates) was 1/2, and isolates of serotype 4 (3.3%) were rare. There was no connection between food sectors and RTs or PFGE types, but PFGE indicated the single plants (78.3% of the types) better than ribotyping (56.5%). On the basis of its automation and on the availability of identification databases, automated ribotyping had some advantages over PFGE. Overall, automated ribotyping can be considered a practical and rapid tool when Listeria contamination is suspected and when screening a large number of isolates is necessary, e.g., when tracing contamination sources. However, in cases of outbreaks, the identical patterns must be confirmed by PFGE, which is a more discriminatory method.

KREATYWNOŚĆ JAKO IMPERATYW I ATRYBUT WSPÓŁCZESNEGO PRZEDSIĘBIORSTWA

2018 ◽  
pp. 41-47
Author(s):  
Cezary Suszyński
Keyword(s):  
Sensu Stricto

Artykuł jest teoretycznym studium wspartym odniesieniami do praktyki zarządzania, którego celem jest przedstawienie argumentacji na rzecz tezy o kreatywności organizacyjnej jako imperatywie i zarazem atrybucie współczesnego przedsiębiorstwa (sensu largo). Obszarem studiów są wybrane teorie ekonomiczne (klasyczna, neoklasyczna, schumpeterowska, instytucjonalna) oraz niektóre koncepcje na gruncie zarządzania strategicznego (strategia jako: wzorzec, zestaw kluczowych kompetencji, zasobów i umiejętności przedsiębiorstwa, przełomowe innowacje, współkreowanie wartości). Analiza uwzględniająca obie perspektywy ujawnia immanentny charakter kreatywności organizacyjnej w procesach wzrostu i rozwoju przedsiębiorstw, zwłaszcza od fazy wykształcenia się zarządzania strategicznego. Wyraźnie rosnąca dynamika zmian (turbulencji) otoczenia przedsiębiorstw skłania je do sięgania po nowe rozwiązania w zakresie idei, koncepcji, zasobów, strategii, modeli biznesu, nadając organizacyjnej kreatywności charakter atrybutu współczesnego przedsiębiorstwa. Dodatkowy wniosek w świetle poczynionych konstatacji co do atrybutowego charakteru kreatywności organizacyjnej wskazuje również jako dyskusyjne spotykane w literaturze przedmiotu określenie "przedsiębiorstwo kreatywne", stosowane w odniesieniu do grupy przedsiębiorstw (sensu stricto) reprezentujących sektory (branże, przemysły) kreatywne. (

Molecular phylogeny and taxonomic evaluation of the genus Asaccus Dixon and Anderson, 1973 (Reptilia: Phyllodactylidae) in Iran

2020 ◽  
pp. 207-214
Author(s):  
Akbar Fattahi
Keyword(s):  
Molecular Phylogeny ◽  
Nuclear Gene ◽  
Genetic Distances ◽  
Genetic Lineage ◽  
New Taxon ◽  
Zagros Mountains ◽  
Relict Species ◽  
Taxonomical Revision ◽  
Two Populations ◽  
Taxonomic Evaluation

The Iranian species of the phyllodactylid geckos of the genus Asaccus are found only in the valleys of the Zagros Mountains, a region which represents an important area of endemism in western Iran. Recently, many relict species have been described from the central and southern parts of the Zagros Mountains, which were previously known as A. elisae. The recent descriptions of species within this complex suggest that diversity within the genus may be higher than expected and that its taxonomy and systematics should be revised. In the present study, phylogenetic relationships within the genus Asaccus were evaluated using two mitochondrial and one nuclear gene. Genetically, the genus shows high levels of variability. The molecular phylogeny of the genus suggests the presence of three main clades along the Zagros Mountains with the southern population (from the Hormozgan province) and one clade (A. sp8 and A. sp9) being sister taxon to A. montanus from UAE. The remaining samples are separated into two reciprocally monophyletic groups: the northern (Kurdistan, Kermanshah and Ilam provinces) and the central (Lorestan, Khuzestan, Kohgilouye-Bouyer Ahmad and Fars provinces) Zagros groups. The results of the present study suggest that populations attributed to A. elisae in Iran correspond to distinct lineages with high genetic distances. In brief, our results suggest that the genus needs a major taxonomical revision The Arabian origin of the genus has not been confirmed, because two populations from Zagros were located within the A. montanus, A. gallagheri and A. platyrhynchus clade. Further morphological analyses are needed to systematically define each genetic lineage as a new taxon.

Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

2019 ◽  
Vol 26 (2) ◽  
pp. 63-71
Author(s):  
Ling Leng ◽  
Ying Wang ◽  
Peixian Yang ◽  
Takashi Narihiro ◽  
Masaru Konishi Nobu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Microbial Consortia ◽  
Chain Elongation ◽  
Desulfovibrio Vulgaris ◽  
Rrna Gene ◽  
Selective Enrichment ◽  
Microbial Network ◽  
Cost Efficient ◽  
Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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