- A multiplex serologic platform for diagnosis of tick-borne diseases. [Journal Article]
- SRSci Rep 2018 Feb 16; 8(1):3158
- Tick-borne diseases are the most common vector-borne diseases in the United States, with serology being the primary method of diagnosis. We developed the first multiplex, array-based assay for serodi...
Tick-borne diseases are the most common vector-borne diseases in the United States, with serology being the primary method of diagnosis. We developed the first multiplex, array-based assay for serodiagnosis of tick-borne diseases called the TBD-Serochip. The TBD-Serochip was designed to discriminate antibody responses to 8 major tick-borne pathogens present in the United States, including Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Borrelia miyamotoi, Ehrlichia chaffeensis, Rickettsia rickettsii, Heartland virus and Powassan virus. Each assay contains approximately 170,000 12-mer linear peptides that tile along the protein sequence of the major antigens from each agent with 11 amino acid overlap. This permits accurate identification of a wide range of specific immunodominant IgG and IgM epitopes that can then be used to enhance diagnostic accuracy and integrate differential diagnosis into a single assay. To test the performance of the TBD-Serochip, we examined sera from patients with confirmed Lyme disease, babesiosis, anaplasmosis, and Powassan virus disease. We identified a wide range of specific discriminatory epitopes that facilitated accurate diagnosis of each disease. We also identified previously undiagnosed infections. Our results indicate that the TBD-Serochip is a promising tool for a differential diagnosis not available with currently employed serologic assays for TBDs.
- Phylogenetic evidence for the existence of multiple strains ofRickettsia parkeriin the New World. [Journal Article]
- AEAppl Environ Microbiol 2018 Feb 09
- The bacteriumRickettsia parkerihas been reported infecting ticks of the 'Amblyomma maculatumspecies complex' in the New World, where it causes spotted fever illness in humans. In South America, three...
The bacteriumRickettsia parkerihas been reported infecting ticks of the 'Amblyomma maculatumspecies complex' in the New World, where it causes spotted fever illness in humans. In South America, three additional rickettsial strains, namely Atlantic rainforest, NOD, and Parvitarsum have been isolated from the ticksAmblyomma ovale, Amblyomma nodosum,andAmblyomma parvitarsum,respectively. These three strains are phylogenetically closely related toR. parkeri, Rickettsia africae,andRickettsia sibirica.Herein, we performed a robust phylogenetic analysis encompassing 5 genes (gltA, ompA, virB4, dnaA, dnaK) and 3 intergenic spacers (mppE-pur, rrl-rrf-ITS, rpmE-tRNAfmet) from 41 rickettsial isolates, including different isolates ofR. parkeri, R. africae, R. sibirica, R. conorii,and strains Atlantic rainforest, NOD, and Parvitarsum. In our phylogenetic analyses, all New World isolates grouped in a major clade distinct from the Old WorldRickettsiaspecies (R. conorii, R. sibirica, R. africae). This New World clade was subdivided into the following 4 clades: theR. parkerisensu stricto clade, comprising the type strain Maculatum 20Tand all other isolates ofR. parkerifrom North and South America, associated with ticks of theA. maculatumspecies complex; the strain NOD clade, comprising two South American isolates fromA. nodosumticks; the Parvitarsum clade, comprising two South American isolates fromA. parvitarsumticks; and, the strain Atlantic rainforest clade, comprising six South American isolates from theA. ovalespecies complex (A. ovaleorA. aureolatum). Under such evidences, we propose that strains Atlantic rainforest, NOD, and Parvitarsum are South American strains ofR. parkeri.ImportanceSince the description ofRickettsia parkeriinfecting ticks of the 'Amblyomma maculatumspecies complex' and humans in the New World, three novel phylogenetic close-related ricketsial isolates were reported in South America. Herein, we provide genetic evidence that these novel isolates, namely strains Atlantic rainforest, NOD, and Parvitarsum, are South American strains ofR. parkeri.Interestingly, each of theseR. parkeristrains seem to be primarily associated with a tick species group, namely,R. parkerisensu stricto with the 'A. maculatumspecies group',R. parkeristrain NOD withA. nodosum, R. parkeristrain Parvitarsum withA. parvitarsum,andR. parkeristrain Atlantic rainforest with 'A. ovalespecies group'. Such rickettsial strain-tick species specificity suggests coevolution of each tick-strain association. Finally, becauseR. parkerisensu stricto andR. parkeristrain Atlantic rainforest are human pathogens, the potential ofR. parkeristrains NOD and Parvitarsum to be human pathogen cannot be discarded.
- Whole-Genome Sequence of Human Rhinovirus C47, Isolated from an Adult Respiratory Illness Outbreak in Butte County, California, 2017. [Journal Article]
- GAGenome Announc 2018 Feb 01; 6(5)
- Here, we report the full coding sequence of rhinovirus C47 (RV-C47), obtained from a patient respiratory sample collected during an acute respiratory illness investigation in Butte County, California...
Here, we report the full coding sequence of rhinovirus C47 (RV-C47), obtained from a patient respiratory sample collected during an acute respiratory illness investigation in Butte County, California, in January 2017. This is the first whole-genome sequence of RV-C47 to be reported.
- Molecular diagnosis of skin infections using paraffin-embedded tissue - review and interdisciplinary consensus. [Review]
- JDJ Dtsch Dermatol Ges 2018; 16(2):139-147
- Nucleic acid amplification techniques (NATs), such as PCR, are highly sensitive and specific methods that have become valuable supplements to culture and serology in the diagnosis of infectious disor...
Nucleic acid amplification techniques (NATs), such as PCR, are highly sensitive and specific methods that have become valuable supplements to culture and serology in the diagnosis of infectious disorders. However, especially when using formalin-fixed and paraffin-embedded tissue, these techniques are associated with both false-negative and false-positive results, a pitfall that is frequently misjudged. Representatives of the German Society of Hygiene and Microbiology (DGHM) and the German Society of Dermatology (DDG) therefore set out to develop a consensus - in the form of a review article - on the appropriate indications for NATs using paraffin-embedded tissue, its contraindications, and the key points to be considered in the pre- and post-analytical phase. Given that fresh, naive tissue is preferably to be used in the workup of a suspected infection, PCR analysis on paraffin sections represents an exception. The latter may be considered if an infection is suspected at a later point in time and fresh tissue has not been preserved or can no longer be obtained. Potential indications include confirmation of histologically suspected infections with Leishmania spp., Bartonella spp., Rickettsia spp., or in case of ecthyma contagiosum. Infections with, for example, mycobacteria or RNA viruses, on the other hand, are not considered useful indications for NATs using paraffin sections. In order to avoid misinterpretation of test results, it is essential that laboratory reports on NATs using paraffin-embedded tissue contain information on the indication/diagnostic circumstances, the required and chosen pre-analytical steps, the limitations of the method, and on diagnostic alternatives.
- Rickettsioses in Denmark: A retrospective survey of clinical features and travel history. [Journal Article]
- TTTicks Tick Borne Dis 2018 Feb 01
- Rickettsia spp. can be found across the globe and cause disease of varying clinical severity, ranging from life-threatening infections with widespread vasculitis to milder, more localized presentatio...
Rickettsia spp. can be found across the globe and cause disease of varying clinical severity, ranging from life-threatening infections with widespread vasculitis to milder, more localized presentations. Vector and, to some degree, reservoir are hematophagous arthropods, with most species harboured by ticks. In Denmark, rickettsiae are known as a cause of imported travel-related infections, but are also found endemically in ticks across the country. Data are, however, lacking on the geographical origin and clinical features of diagnosed cases. In this study, we have examined the travel history and clinical features of two groups of patients; 1) hospital-patients diagnosed with rickettsioses in the years 2010-2015 and 2) patients from primary health care (PHC) centers in Denmark having demonstrated anti-rickettsia antibodies in the years 2012-2015. The patients were identified using the Danish National Patient Registry (DNPR) and through the serological database at the State Serum Institute, where the laboratory diagnosis of rickettsioses is currently centralized. Data were collected for 86 hospital patients and 26 PHC center patients by reviewing hospital medical records and performing telephone interviews with PHC centers. Of the hospital patients, 91% (78/86) had a history of international travel 14 days prior to symptom start, with most having imported their infection from southern Africa, South Africa in particular (65%), and presenting with a clinical picture most compatible with African tick-bite fever caused by R. africae. Only two patients presented with a CRP > 100 mg/L and no mortalities were reported. At the PHC centers, most patients presented with mild flu-like symptoms and had an unknown (50%) or no history (19%) of international travel, raising the possibility of endemic rickettsioses. In view of our findings, rickettsioses do not appear to constitute a major public health problem in Denmark, with most cases being imported infections and potential endemic cases presenting as mild infections.
- High prevalence of Rickettsia helvetica in wild small mammal populations in Germany. [Journal Article]
- TTTicks Tick Borne Dis 2018 Feb 02
- Since the beginning of the 21st century, spotted fever rickettsioses are known as emerging diseases worldwide. Rickettsiae are obligately intracellular bacteria transmitted by arthropod vectors. The ...
Since the beginning of the 21st century, spotted fever rickettsioses are known as emerging diseases worldwide. Rickettsiae are obligately intracellular bacteria transmitted by arthropod vectors. The ecology of Rickettsia species has not been investigated in detail, but small mammals are considered to play a role as reservoirs. Aim of this study was to monitor rickettsiae in wild small mammals over a period of five years in four federal states of Germany. Initial screening of ear pinna tissues of 3939 animals by Pan-Rick real-time PCR targeting the citrate synthase (gltA) gene revealed 296 rodents of seven species and 19 shrews of two species positive for rickettsial DNA. Outer membrane protein gene (ompB, ompAIV) PCRs based typing resulted in the identification of three species: Rickettsia helvetica (90.9%) was found as the dominantly occurring species in the four investigated federal states, but Rickettsia felis (7.8%) and Rickettsia raoultii (1.3%) were also detected. The prevalence of Rickettsia spp. in rodents of the genus Apodemus was found to be higher (approximately 14%) than in all other rodent and shrew species at all investigated sites. General linear mixed model analyses indicated that heavier (older) individuals of yellow-necked mice and male common voles seem to contain more often rickettsial DNA than younger ones. Furthermore, rodents generally collected in forests in summer and autumn more often carried rickettsial DNA. In conclusion, this study indicated a high prevalence of R. helvetica in small mammal populations and suggests an age-dependent increase of the DNA prevalence in some of the species and in animals originating from forest habitats. The finding of R. helvetica and R. felis DNA in multiple small mammal species may indicate frequent trans-species transmission by feeding of vectors on different species. Further investigations should target the reason for the discrepancy between the high rickettsial DNA prevalence in rodents and the so far almost absence of clinical apparent human infections.
- Endosymbiont diversity and prevalence in herbivorous spider mite populations in South-Western Europe. [Journal Article]
- FMFEMS Microbiol Ecol 2018 Jan 30
- Bacterial endosymbionts are known as important players of the evolutionary ecology of their hosts. However, their distribution, prevalence and diversity are still largely unexplored. To this aim, we ...
Bacterial endosymbionts are known as important players of the evolutionary ecology of their hosts. However, their distribution, prevalence and diversity are still largely unexplored. To this aim, we investigated infections by the most common bacterial reproductive manipulators in herbivorous spider mites of South-Western Europe. Across 16 populations belonging to three Tetranychus species, Wolbachia was the most prevalent (ca. 61%), followed by Cardinium (12-15%), while only few individuals were infected by Rickettsia (0.9-3%), and none carried Arsenophonus or Spiroplasma. These endosymbionts are here reported for the first time in T. evansi and T. ludeni, and showed variable infection frequencies between and within species, with several cases of coinfections. Moreover, Cardinium was more prevalent in Wolbachia-infected individuals, which suggests facilitation between these symbionts. Finally, sequence comparisons revealed no variation of the Wolbachia wsp and Rickettsia gtlA genes, but some diversity of the Cardinium 16S rRNA, both between and within populations of the three mite species. Some of the Cardinium sequences identified belonged to distantly related clades, and the lack of association between these sequences and spider mite mitotypes suggests repeated host switching of Cardinium. Overall, our results reveal a complex community of symbionts in this system, opening the path for future studies.
- Development of a loop-mediated isothermal amplification (LAMP) assay for rapid screening of ticks and fleas for spotted fever group rickettsia. [Journal Article]
- PlosPLoS One 2018; 13(2):e0192331
- CONCLUSIONS: To our knowledge, this is the first study to develop a functional LAMP assay to initially screen for SFG and TRG rickettsia pathogens in field-collected ticks and fleas. With a high sensitivity and specificity, the results indicate the potential use as a field-based surveillance tool for tick and flea-borne rickettsial pathogens in resource-challenged countries.
- Rickettsia parkeri infections diagnosed by eschar biopsy, Virginia, USA. [Journal Article]
- IInfection 2018 Jan 31
- CONCLUSIONS: DNA testing of eschars represents an under-utilized diagnostic test and may aid in cases where the diagnosis is not made clinically.
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- Bilateral arterial occlusions masking retinitis in a HIV-positive male. [Case Reports]
- IJIndian J Ophthalmol 2018; 66(2):332-334
- We report an interesting case of 36-year-old HIV-positive male with uveitis, cilioretinal artery occlusion in OD, and superotemporal branch retinal artery occlusion in OS. Hypercoagulability, cardiov...
We report an interesting case of 36-year-old HIV-positive male with uveitis, cilioretinal artery occlusion in OD, and superotemporal branch retinal artery occlusion in OS. Hypercoagulability, cardiovascular, and rheumatologic workups were unremarkable. Aqueous taps were negative for toxoplasma, viruses, and MTb by multiplex polymerase chain reaction. Patches of retinitis were seen on clearing of retinal edema. Serology was positive for toxoplasma and rickettsia. Management included doxycycline, azithromycin, bactrim DS, and oral steroids. Vision improvement to 6/60 and 6/24 in OD and OS refer to the right eye and left eye, respectively, were noted at 4-month follow-up. Infections should be considered in arterial occlusions associated with inflammation in HIV-positive individuals.