scholarly journals Rickettsia monacensis sp. nov., a Spotted Fever Group Rickettsia, from Ticks (Ixodes ricinus) Collected in a European City Park

2002 ◽  
Vol 68 (9) ◽  
pp. 4559-4566 ◽  
Author(s):  
Jason A. Simser ◽  
Ann T. Palmer ◽  
Volker Fingerle ◽  
Bettina Wilske ◽  
Timothy J. Kurtti ◽  
...  
Keyword(s):  
Cell Lines ◽  
Ixodes Ricinus ◽  
Mammalian Cells ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Mammalian Cell Lines ◽  
Isolation And Characterization ◽  
Rickettsia Monacensis ◽  
City Park

ABSTRACT We describe the isolation and characterization of Rickettsia monacensis sp. nov. (type strain, IrR/MunichT) from an Ixodes ricinus tick collected in a city park, the English Garden in Munich, Germany. Rickettsiae were propagated in vitro with Ixodes scapularis cell line ISE6. BLAST analysis of the 16S rRNA, the citrate synthase, and the partial 190-kDa rickettsial outer membrane protein A (rOmpA) gene sequences demonstrated that the isolate was a spotted fever group (SFG) rickettsia closely related to several yet-to-be-cultivated rickettsiae associated with I. ricinus. Phylogenetic analysis of partial rompA sequences demonstrated that the isolate was genotypically different from other validated species of SFG rickettsiae. R. monacensis also replicated in cell lines derived from the ticks I. ricinus (IRE11) and Dermacentor andersoni (DAE100) and in the mammalian cell lines L-929 and Vero, causing cell lysis. Transmission electron microscopy of infected ISE6 and Vero cells showed rickettsiae within the cytoplasm, pseudopodia, nuclei, and vacuoles. Hamsters inoculated with R. monacensis had immunoglobulin G antibody titers as high as 1:16,384, as determined by indirect immunofluorescence assay. Western blot analyses demonstrated that the hamster sera cross-reacted with peptides from other phylogenetically distinct rickettsiae, including rOmpA. R. monacensis induced actin tails in both tick and mammalian cells similar to those reported for R. rickettsii. R. monacensis joins a growing list of SFG rickettsiae that colonize ticks but whose infectivity and pathogenicity for vertebrates are unknown.

scholarly journals Detection of tick-borne pathogens in questing Ixodes ricinus in the French Pyrenees and first identification of Rickettsia monacensis in France

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 20 ◽  
Author(s):  
Toufic Akl ◽  
Gilles Bourgoin ◽  
Marie-Line Souq ◽  
Joël Appolinaire ◽  
Marie-Thérèse Poirel ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Pathogen Detection ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Rupicapra Pyrenaica ◽  
Rickettsia Monacensis ◽  
Animal Pathogens ◽  
Questing Ticks ◽  
Pyrenean Chamois ◽  
First Time

Ticks are important vectors of several human and animal pathogens. In this study, we estimated the prevalence of important tick-borne infections in questing ticks from an area in Southwestern France (Hautes-Pyrénées) inhabited by Pyrenean chamois (Rupicapra pyrenaica pyrenaica) experiencing high tick burden. We examined adult and nymph ticks collected by the flag dragging method from 8 to 15 sites in the Pic de Bazès during the years 2009, 2011, 2013 and 2015. PCR assays were conducted on selected ticks for the detection of Borrelia burgdorferi s.l., Babesia spp., Rickettsia spp., spotted fever group (SFG) Rickettsia and Anaplasma phagocytophilum. Randomly selected positive samples were submitted for sequence analysis. A total of 1971 questing ticks were collected including 95 males, 101 females and 1775 nymphs. All collected ticks were identified as Ixodes ricinus. Among them, 696 ticks were selected for pathogen detection and overall prevalence was 8.4% for B. burgdorferi s.l.; 0.4% for Babesia spp.; 6.1% for A. phagocytophilum; 17.6% for Rickettsia spp.; and 8.1% for SFG Rickettsia. Among the sequenced pathogens, we detected in this population of ticks the presence of Babesia sp. EU1 and Rickettsia helvetica, as well as Rickettsia monacensis for the first time in France. The detection of these pathogens in the Pic de Bazès highlights the potential infection risks for visitors to this area and the Pyrenean chamois population.

scholarly journals Rickettsia helvetica in Ixodes ricinus Ticks in Sweden

1999 ◽  
Vol 37 (2) ◽  
pp. 400-403 ◽  
Author(s):  
Kenneth Nilsson ◽  
Olle Lindquist ◽  
Ai Jie Liu ◽  
Thomas G. T. Jaenson ◽  
Göran Friman ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Oligonucleotide Primer ◽  
Rrna Gene ◽  
Spotted Fever Group ◽  
Rflp Pattern ◽  
Rickettsia Helvetica ◽  
Pcr Rflp ◽  
Ixodes Ricinus Ticks

In the present study further characterization of the amplified sequence of the citrate synthase gene of the spotted fever groupRickettsia isolated from Ixodes ricinus ticks in Sweden showed that it has 100% homology with the deposited sequence of the citrate synthase gene of Rickettsia helvetica. The restriction fragment length polymorphism (RFLP) pattern of an amplified 382-bp product of the citrate synthase sequence, defined by primers RpCS877 and RpCS1258, yielded fragments for our isolate that could be visualized as a double band that migrated at approximately 44 bp, another double band at 85 bp, and a single band at nearly 120 bp after digestion with the restriction enzyme AluI. When calculating a theoretical PCR-RFLP pattern of the sequence of the citrate synthase gene of R. helvetica from the known positions where the AluI enzyme cuts, we arrived at the same pattern that was obtained for our isolate, a pattern distinctly different from the previously published PCR-RFLP pattern for R. helvetica. Investigation of 125 living I. ricinusticks showed a higher prevalence of rickettsial DNA in these ticks than we had found in an earlier study. Rickettsial DNA was detected by amplification of the 16S rRNA gene, for which a seminested primer system consisting of two oligonucleotide primer pairs was used. Of the 125 ticks, some were pooled, giving a total of 82 tick samples, of which 20 were found to be positive for the rickettsial DNA gene investigated. When considering the fact that some of the positive samples were pooled, the minimum possible prevalence in these ticks was 20 of 125 (16%) and the maximum possible prevalence was 46 of 125 (36.8%). These prevalence estimates conform to those of other studies of spotted fever group rickettsiae in hard ticks in Europe.

scholarly journals Role of reptiles and associated arthropods in the epidemiology of rickettsioses: A one health paradigm

2021 ◽  
Vol 15 (2) ◽  
pp. e0009090 ◽  
Author(s):  
Jairo Alfonso Mendoza-Roldan ◽  
Ranju Ravindran Santhakumari Manoj ◽  
Maria Stefania Latrofa ◽  
Roberta Iatta ◽  
Giada Annoscia ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Human Subjects ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Sylvatic Cycle ◽  
Podarcis Muralis ◽  
Nature Preserve ◽  
Forestry Workers ◽  
Rickettsia Monacensis ◽  
Podarcis Siculus

We assessed the presence of Rickettsia spp., Coxiella burnetii and Anaplasma phagocytophilum in reptiles, their ectoparasites and in questing ticks collected in a nature preserve park in southern Italy, as well as in a peri-urban area in another region. We also investigated the exposure to these pathogens in forestry workers, farmers and livestock breeders living or working in the nature preserve park given the report of anecdotal cases of spotted fever rickettsioses. Rickettsia spp. were molecularly detected in Podarcis muralis and Podarcis siculus lizards (i.e., 3.1%), in Ixodes ricinus (up to 87.5%) and in Neotrombicula autumnalis (up to 8.3%) collected from them as well as in I. ricinus collected from the environment (up to 28.4%). Rickettsia monacensis was the most prevalent species followed by Rickettsia helvetica. An undescribed member of the family Anaplasmataceae was detected in 2.4% and 0.8% of the reptiles and ectoparasites, respectively. Sera from human subjects (n = 50) were serologically screened and antibodies to Rickettsia spp. (n = 4; 8%), C. burnetti (n = 8; 16%) and A. phagocytophilum (n = 11; 22%) were detected. Two ticks collected from two forestry workers were positive for spotted fever group (SFG) rickettsiae. Ixodes ricinus is involved in the transmission of SFG rickettsiae (R. monacensis and R. helvetica) in southern Europe and lizards could play a role in the sylvatic cycle of R. monacensis, as amplifying hosts. Meanwhile, N. autumnalis could be involved in the enzootic cycle of some SFG rickettsiae among these animals. People living or working in the southern Italian nature preserve park investigated are exposed to SFG rickettsiae, C. burnetii and A. phagocytophilum.

scholarly journals Zoonotic Rickettsia Species in Small Ruminant Ticks From Tunisia

2021 ◽  
Vol 8 ◽  
Author(s):  
Hanène Belkahia ◽  
Rachid Selmi ◽  
Sayed Zamiti ◽  
Monia Daaloul-Jedidi ◽  
Lilia Messadi ◽  
...  
Keyword(s):  
Small Ruminant ◽  
Citrate Synthase ◽  
Spotted Fever ◽  
Protein A ◽  
Rhipicephalus Sanguineus ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
Rickettsia Monacensis ◽  
Significant Public Health ◽  
Pcr Targeting

Tick-borne rickettsioses present a significant public health threat among emerging tick-borne diseases. In Tunisia, little is known about tick-borne Rickettsia pathogens. Therefore, the aim of this study was to investigate the presence of Rickettsia species in small ruminant ticks from Tunisia. Adult ticks (n = 694) were collected from goats and sheep in northern Tunisia. Obtained ticks were identified as Rhipicephalus turanicus (n = 434) and Rhipicephalus sanguineus sensu lato (n = 260). Selected ticks (n = 666) were screened for the presence of Rickettsia spp. by PCR targeting a partial sequence of the ompB gene followed by sequence analysis. Rickettsial DNA was detected in 122 (18.3%) tested tick samples. The infection rates in Rh. turanicus and Rh. sanguineus s.l. ticks were 23.4 and 9.5%, respectively. The overall prevalence of rickettsial DNA was markedly higher in ticks collected from goats (23.2%) compared to those infesting sheep (7.9%). The detection of rickettsial DNA was significantly higher in ticks from the governorate of Beja (39.0%) than those from the governorate of Bizerte (13.9%). Two additional genes, the outer membrane protein A gene (ompA) and the citrate synthase gene (gltA), were also targeted for further characterization of the detected Rickettsia species. Genotyping and phylogenetic analysis based on partial sequences (n = 106) of the three different genes revealed that positive ticks are infected with different isolates of two Spotted Fever Group (SFG) Rickettsia, namely, Rickettsia massiliae and Rickettsia monacensis, closely related to those infecting camels and associated ticks from Tunisia, and humans and small ruminant ticks from neighboring countries like Italy, France, and Spain.

Cytotoxicity Study of Textile Fabrics Impregnated With CuO Nanoparticles in Mammalian Cells

2017 ◽  
Vol 36 (6) ◽  
pp. 478-484 ◽  
Author(s):  
Gagandeep Singh ◽  
James Beddow ◽  
Christopher Mee ◽  
Lidia Maryniak ◽  
Eadaoin M. Joyce ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mammalian Cells ◽  
Dermal Fibroblast ◽  
Copper Oxide Nanoparticles ◽  
Growth Media ◽  
Indirect Contact ◽  
Cuo Nps ◽  
Mammalian Cell Lines ◽  
Textile Fabrics ◽  
Hdf Cells

Copper and copper compounds have multifunctional properties (antibacterial, antiviral, and antifungal) with promising applications. Copper in its nanoparticle (Cu NPs) forms has been widely used in various industrial and commercial applications. In the current research, the cytotoxic effects of textile fabrics impregnated with copper oxide nanoparticles (CuO NPs) were studied in mammalian cell lines. CuO NPs were impregnated onto textile substrates using 2 different techniques: the sonochemical generation and impregnation of NPs from metal complexes ( insitu) and a “throwing the stones” technology using commercially prepared CuO NPs. The cytotoxicity of these 2 textile fabric types was assayed on human dermal fibroblast (HDF) cells and human hepatocellular carcinoma cells (HepG2) and was evaluated by indirect contact using an MTT assay. The impregnated fabrics were not exposed to the cells, rather their leachates were used to test cytotoxicity. The fabrics were soaked into the growth media for up to 7 days, and the leachates from day 1 and day 7 were incubated with the cell lines for 24 hours prior to the testing. The discharge or leaching from antimicrobial nanomaterials into the surroundings and surface waters is posing a serious environmental threat, which needs to be addressed. Hence, with regard to product safety, it is a good approach to study the fabric leachates rather than the intact material. The results showed that CuO NPs are not toxic to HDF cells. However, cytotoxicity was seen in HepG2 cells with cell viability decreasing by 20% to 25% for all the fabrics after 24 hours.

scholarly journals Ecological Factors Characterizing the Prevalence of Bacterial Tick-Borne Pathogens in Ixodes ricinus Ticks in Pastures and Woodlands

2010 ◽  
Vol 76 (13) ◽  
pp. 4413-4420 ◽  
Author(s):  
Lénaïg Halos ◽  
Séverine Bord ◽  
Violaine Cotté ◽  
Patrick Gasqui ◽  
David Abrial ◽  
...  
Keyword(s):  
Forest Fragmentation ◽  
Ixodes Ricinus ◽  
Spotted Fever ◽  
Ecological Factors ◽  
Adult Tick ◽  
Reservoir Host ◽  
Host Community ◽  
Infection Prevalence ◽  
Spotted Fever Group ◽  
Reservoir Hosts

ABSTRACT Ecological changes are recognized as an important driver behind the emergence of infectious diseases. The prevalence of infection in ticks depends upon ecological factors that are rarely taken into account simultaneously. Our objective was to investigate the influences of forest fragmentation, vegetation, adult tick hosts, and habitat on the infection prevalence of three tick-borne bacteria, Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Rickettsia sp. of the spotted fever group, in questing Ixodes ricinus ticks, taking into account tick characteristics. Samples of questing nymphs and adults were taken from 61 pastures and neighboring woodlands in central France. The ticks were tested by PCR of pools of nymphs and individual adults. The individual infection prevalence was modeled using multivariate regression. The highest infection prevalences were found in adult females collected in woodland sites for B. burgdorferi sensu lato and A. phagocytophilum (16.1% and 10.7%, respectively) and in pasture sites for Rickettsia sp. (8.7%). The infection prevalence in nymphs was lower than 6%. B. burgdorferi sensu lato was more prevalent in woodlands than in pastures. Forest fragmentation favored B. burgdorferi sensu lato and A. phagocytophilum prevalence in woodlands, and in pastures, the B. burgdorferi sensu lato prevalence was favored by shrubby vegetation. Both results are probably because large amounts of edges or shrubs increase the abundance of small vertebrates as reservoir hosts. The Rickettsia sp. prevalence was maximal on pasture with medium forest fragmentation. Female ticks were more infected by B. burgdorferi sensu lato than males and nymphs in woodland sites, which suggests an interaction between the ticks and the bacteria. This study confirms the complexity of the tick-borne pathogen ecology. The findings support the importance of small vertebrates as reservoir hosts and make a case for further studies in Europe on the link between the composition of the reservoir host community and the infection prevalence in ticks.

scholarly journals ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

2008 ◽  
Vol 76 (10) ◽  
pp. 4600-4608 ◽  
Author(s):  
Karin Heine ◽  
Sascha Pust ◽  
Stefanie Enzenmüller ◽  
Holger Barth
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Clostridium Botulinum ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Adp Ribosylation ◽  
Mammalian Cell Lines ◽  
Adp Ribosyltransferase ◽  
C2 Toxin

ABSTRACT The binary C2 toxin from Clostridium botulinum mono-ADP-ribosylates G-actin in the cytosol of eukaryotic cells. This modification leads to depolymerization of actin filaments accompanied by cell rounding within 3 h of incubation but does not immediately induce cell death. Here we investigated the long-term responses of mammalian cell lines (HeLa and Vero) following C2 toxin treatment. Cells stayed round even though the toxin was removed from the medium after its internalization into the cells. No unmodified actin reappeared in the C2 toxin-treated cells within 48 h. Despite actin being completely ADP-ribosylated after about 7 h, no obvious decrease in the overall amount of actin was observed for at least 48 h. Therefore, ADP-ribosylation was not a signal for an accelerated degradation of actin in the tested cell lines. C2 toxin treatment resulted in delayed apoptotic cell death that became detectable about 15 to 24 h after toxin application in a portion of the cells. Poly(ADP)-ribosyltransferase 1 (PARP-1) was cleaved in C2 toxin-treated cells, an indication of caspase 3 activation and a hallmark of apoptosis. Furthermore, specific caspase inhibitors prevented C2 toxin-induced apoptosis, implying that caspases 8 and 9 were activated in C2 toxin-treated cells. C2I, the ADP-ribosyltransferase component of the C2 toxin, remained active in the cytosol for at least 48 h, and no extensive degradation of C2I was observed. From our data, we conclude that the long-lived nature of C2I in the host cell cytosol was essential for the nonreversible cytotoxic effect of C2 toxin, resulting in delayed apoptosis of the tested mammalian cells.

scholarly journals Characterization of a spotted fever group Rickettsia from Ixodes ricinus ticks in Sweden.

1997 ◽  
Vol 35 (1) ◽  
pp. 243-247 ◽  
Author(s):  
K Nilsson ◽  
T G Jaenson ◽  
I Uhnoo ◽  
O Lindquist ◽  
B Pettersson ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Ixodes Ricinus Ticks ◽  
Spotted Fever Group Rickettsia

scholarly journals Cell Line Classification Using Electric Cell-Substrate Impedance Sensing (ECIS)

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Megan L. Gelsinger ◽  
Laura L. Tupper ◽  
David S. Matteson
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Statistical Tests ◽  
Classification Methods ◽  
Impedance Sensing ◽  
Mammalian Cell Lines ◽  
Cell Substrate ◽  
Multiple Cell ◽  
Line Classification

AbstractWe present new methods for cell line classification using multivariate time series bioimpedance data obtained from electric cell-substrate impedance sensing (ECIS) technology. The ECIS technology, which monitors the attachment and spreading of mammalian cells in real time through the collection of electrical impedance data, has historically been used to study one cell line at a time. However, we show that if applied to data from multiple cell lines, ECIS can be used to classify unknown or potentially mislabeled cells, factors which have previously been associated with the reproducibility crisis in the biological literature. We assess a range of approaches to this new problem, testing different classification methods and deriving a dictionary of 29 features to characterize ECIS data. Most notably, our analysis enriches the current field by making use of simultaneous multi-frequency ECIS data, where previous studies have focused on only one frequency; using classification methods to distinguish multiple cell lines, rather than simple statistical tests that compare only two cell lines; and assessing a range of features derived from ECIS data based on their classification performance. In classification tests on fifteen mammalian cell lines, we obtain very high out-of-sample predictive accuracy. These preliminary findings provide a baseline for future large-scale studies in this field.

Response of cultured mammalian cells to the exotoxins of Pseudomonas aeruginosa and Corynebacterium diphtheriae: differential cytotoxicity

1977 ◽  
Vol 23 (2) ◽  
pp. 183-189 ◽  
Author(s):  
John L. Middlebrook ◽  
Rebecca B. Dorland
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Corynebacterium Diphtheriae ◽  
Pseudomonas Exotoxin ◽  
Intact Cells ◽  
Mammalian Cell Lines ◽  
First Order Kinetics ◽  
Wide Range ◽  
Species Specific

The sensitivities of 21 mammalian cell lines to the exotoxins of Pseudomonas aeruginosa and Corynebacterium diphtheriae were measured. Each line exhibited 1–4 log differences in sensitivities to the two toxins. No species-specific sensitivities were noted for Pseudomonas exotoxin while diphtheria exotoxin was most potent in cells of monkey origin, followed by human and hamster cells. Rat-and mouse-derived cell lines were very in sensitive to diphtheria exotoxin. The rates of cellular intoxication by both toxins exhibited apparent first-order kinetics and were indistinguishable from one another when equipotent doses were used. Our preparation of diphtheria exotoxin appeared to have a slightly higher ADP-ribosylating efficiency than did Pseudomonas toxin. However, neither toxin exhibited cell line–specific differences in ribosylating efficiencies which could have explained the wide range in potencies for intact cells. Our results suggest that there are significant differences in the mechanisms of cellular intoxication by Pseudomonas and diphtheria exotoxins and that these differences probably exist in the attachment or internalization stages of toxin action.

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