Comparison of a multiplex PCR with DNA barcoding for identification of container breeding mosquito species.

BACKGROUND: Identification of mosquitoes greatly relies on morphological specification. Since some species cannot be distinguished reliably by morphological methods, it is important to incorporate molecular techniques into the diagnostic pipeline. DNA barcoding using Sanger sequencing is currently widely used for identification of mosquito species. However, this method does not allow detection of multiple species in one sample, which would be important when analysing mosquito eggs. Detection of container breeding Aedes is typically performed by collecting eggs using ovitraps. These traps consist of a black container filled with water and a wooden spatula inserted for oviposition support. Aedes mosquitoes of different species might lay single or multiple eggs on the spatula. In contrast to Sanger sequencing of specific polymerase chain reaction (PCR) products, multiplex PCR protocols targeting specific species of interest can be of advantage for detection of multiple species in the same sample. METHODS: For this purpose, we adapted a previously published PCR protocol for simultaneous detection of four different Aedes species that are relevant for Austrian monitoring programmes, as they can be found in ovitraps: Aedes albopictus, Aedes japonicus, Aedes koreicus, and Aedes geniculatus. For evaluation of the multiplex PCR protocol, we analysed 2271 ovitrap mosquito samples from the years 2021 and 2022, which were collected within the scope of an Austrian nationwide monitoring programme. We compared the results of the multiplex PCR to the results of DNA barcoding. RESULTS: Of 2271 samples, the multiplex PCR could identify 1990 samples, while species determination using DNA barcoding of the mitochondrial cytochrome c oxidase subunit I gene was possible in 1722 samples. The multiplex PCR showed a mixture of different species in 47 samples, which could not be detected with DNA barcoding. CONCLUSIONS: In conclusion, identification of Aedes species in ovitrap samples was more successful when using the multiplex PCR protocol as opposed to the DNA barcoding protocol. Additionally, the multiplex PCR allowed us to detect multiple species in the same sample, while those species might have been missed when using DNA barcoding with Sanger sequencing alone. Therefore, we propose that the multiplex PCR protocol is highly suitable and of great advantage when analysing mosquito eggs from ovitraps.

Recurrent, ICD-associated L. monocytogenes bacteraemia with multiple septic pulmonary embolisms over a 2-year period.

BACKGROUND: Listeria monocytogenes is a bacterial pathogen known for causing listeriosis, a foodborne illness with a wide spectrum of clinical presentations ranging from mild gastroenteritis to severe invasive disease, particularly affecting immunocompromised individuals, pregnant women, newborns, and the elderly. Successful treatment of patients with recurring listeria episodes due to colonised foreign material is often challenging, typically requiring a combination of antimicrobial treatment and surgical removal. CASE PRESENTATION: Here, we present a particularly complex case of chronic invasive listeriosis with a total of six relapses. After extensive investigations, the patient's ICD device was identified as the focus of infection. CONCLUSION: The confirmation of relapses through cgMLST analysis highlights the persistence of Listeria monocytogenes and the potential for recurrence even after apparent resolution of symptoms in patients with foreign material. It emphasises the necessity for a comprehensive assessment to identify and mitigate the risk of relapses, thereby ensuring optimal management and outcomes.

Three Cases of Tickborne Francisella tularensis Infection, Austria, 2022.

Tularemia is increasing in Austria. We report Francisella tularensis subspecies holarctica isolated from 3 patients who had been bitten by arthropods. Next-generation sequencing showed substantial isolate similarity. Clinicians should consider bloodstream F. tularensis infections for patients with signs/symptoms of ulceroglandular tularemia, and surveillance of potential vectors should be intensified.

Spatiotemporal spread of tick-borne encephalitis in the EU/EEA, 2012 to 2020.

BackgroundTick-borne encephalitis (TBE) is a vaccine-preventable disease involving the central nervous system. TBE became a notifiable disease on the EU/EEA level in 2012.AimWe aimed to provide an updated epidemiological assessment of TBE in the EU/EEA, focusing on spatiotemporal changes.MethodsWe performed a descriptive analysis of case characteristics, time and location using data of human TBE cases reported by EU/EEA countries to the European Centre for Disease Prevention and Control with disease onset in 2012-2020. We analysed data at EU/EEA, national, and subnational levels and calculated notification rates using Eurostat population data. Regression models were used for temporal analysis.ResultsFrom 2012 to 2020, 19 countries reported 29,974 TBE cases, of which 24,629 (98.6%) were autochthonous. Czechia, Germany and Lithuania reported 52.9% of all cases. The highest notification rates were recorded in Lithuania, Latvia, and Estonia (16.2, 9.5 and 7.5 cases/100,000 population, respectively). Fifty regions from 10 countries, had a notification rate ≥ 5/100,000. There was an increasing trend in number of cases during the study period with an estimated 0.053 additional TBE cases every week. In 2020, 11.5% more TBE cases were reported than predicted based on data from 2016 to 2019. A geographical spread of cases was observed, particularly in regions situated north-west of known endemic regions.ConclusionA close monitoring of ongoing changes to the TBE epidemiological situation in Europe can support the timely adaption of vaccination recommendations. Further analyses to identify populations and geographical areas where vaccination programmes can be of benefit are needed.

Tick feeding modulates the human skin immune landscape to facilitate tick-borne pathogen transmission.

During cutaneous tick attachment, the feeding cavity becomes a site of transmission for tick salivary compounds and tick-borne pathogens. However, the immunological consequences of tick feeding for human skin remain unclear. Here, we assessed human skin and blood samples upon tick bite and developed a human skin explant model mimicking Ixodes ricinus bites and tick-borne pathogen infection. Following tick attachment, we observed rapidly occurring patterns of immunomodulation, including increases in neutrophils and cutaneous B and T cells. T cells upregulated tissue residency markers, while lymphocytic cytokine production was impaired. In early stages of Borrelia burgdorferi model infections, we detected strain-specific immune responses and close spatial relationships between macrophages and spirochetes. Preincubation of spirochetes with tick salivary gland extracts hampered accumulation of immune cells and increased spirochete loads. Collectively, we showed that tick feeding exerts profound changes on the skin immune network that interfere with the primary response against tick-borne pathogens.

Borrelia Ecology and Evolution: Ticks and Hosts and the Environment.

The genus Borrelia encompasses bacterial pathogens that can cause Lyme borreliosis (LB) and relapsing fever (RF) [...].

Evidence of taxonomic bias in public databases: The example of the genus Borrelia.

The taxon names used in public databases are of critical importance in all areas of biology because they are needed for linking organisms to sequence data and other information. Since most users of taxonomic classifications may be unprepared for dealing with synonyms, the names that are preferred in such databases are of high impact. Using the genus Borrelia as an example, we here show how simplistic approaches for determining the preferred synonym may lead to biases regarding the preferences for taxonomic opinions. We highlight that in this and other cases where genera were split, for reverting to the previous "merged" genus it is neither possible nor necessary to generate validly published and legitimate names that are newer than those that were proposed as new combinations when the genus was split. The policy to always prefer the latest validly published name in a public database may thus render this database oblivious to reversals in taxonomic opinion. We emphasize that users of public databases should be aware of such potential shortcomings, and that curators of databases which provide nomenclatural information should be open-minded about taxonomic views expressed in the literature.

Nonspecific symptoms following infection with Borrelia burgdorferi sensu lato: A retrospective cohort study.

Whether infection with Borrelia burgdorferi sensu lato (sl) can cause nonspecific symptoms is a matter of controversy. We investigated whether individuals infected with B. burgdorferi sl develop unspecific symptoms more frequently than non-infected controls. Eighty-nine persons having presented with B. burgdorferi sl infection between 2015 and 2019 were asked to participate. The infection was defined as erythema migrans diagnosed either in the course of a previous study, during medical visits in the outpatient department, or as seroconversion in asymptomatic subjects. The control group consisted of 85 seronegative individuals without erythema migrans in the past. About two and a half years later, participants were asked to fill out a questionnaire with a list of nonspecific symptoms. The data of 37 persons with previous Borrelia infection and 49 uninfected controls were available for analysis. Muscle pain was significantly (P = 0.040) more frequent in the control group. Fatigue occurred more often in the infected group, but this was not statistically significant (P = 0.109). Likewise, the distribution of other symptoms did not differ considerably. The analysis revealed no difference in the frequency of symptoms of persons who had EM or asymptomatic Borrelia infection 2 years prior assessment in comparison to persons without Borrelia infection.

Persistent Anti-Borrelia IgM Antibodies without Lyme Borreliosis in the Clinical and Immunological Context.

The aim of the study was to investigate the etiology of persistent IgM antibodies against Borrelia burgdorferi sensu lato (sl) and to analyze their association with nonspecific symptoms. The study group comprised individuals with persistent IgM antibodies in the absence of IgG. The relation between ELISA values and time elapsed since past erythema migrans (EM) was analyzed. Previous antibiotic treatments were assessed. The association between persistent IgM and nonspecific symptoms was evaluated statistically. Specificity of IgM antibodies for outer surface protein C (OspC) of B. burgdorferi sl was examined by immunoblotting. Further, we investigated the cross-reactivity with Borrelia-unrelated proteins. Fifty-nine patients (46 women; 78%) were included in the study group. The mean IgM-ELISA values did not change significantly during follow-up (median 6.2 months). The mean ELISA value in the study group was dependent on time elapsed since past EM. Nonspecific symptoms improved significantly more often in patients with lower IgM ELISA results. Persistent IgM antibodies were specific for the C-terminal PKKP motif of OspC. Cross-reacting C-terminal PKKP antigens from both human and prokaryotic origins were identified. We demonstrate that the C-terminal PKKP motif plays a main role for the reactivity of persistent Borrelia IgM toward OspC. However, cross-reactivity to other eukaryotic and/or prokaryotic antigens may hamper the specificity of OspC in the serological diagnosis of Lyme borreliosis. Lack of improvement of nonspecific symptoms was associated with higher IgM ELISA values. IMPORTANCE The reactivity of human IgM with the outer surface protein C (OspC) of Borrelia burgdorferi sensu lato is frequently used to detect Borrelia specific IgM in commercial immunoassays, and such antibodies usually occur in the early phase of the infection. We identified a group of individuals with persistent Borrelia IgM without symptoms of Lyme borreliosis. We used their sera to demonstrate that the C-terminal epitope of OspC binds the IgM. Strikingly, we found that the same epitope occurs also in certain proteins of human and environmental origin; the latter include other bacteria and food plants. Our experimental data show that these Borrelia-unrelated proteins cross-react with the OpsC-specific IgM. This knowledge is important for the development of serologic assays for Lyme borreliosis and provides a cross-reactive explanation for the persistence of Borrelia-IgM.

Isolation of Francisella tularensis from Skin Ulcer after a Tick Bite, Austria, 2020.

Ulceroglandular tularemia is caused by the transmission of Francisella tularensis by arthropods to a human host. We report a case of tick-borne tularemia in Austria which was followed by an abscess formation in a lymph node, making drainage necessary. F. tularensis subsp. holarctica was identified by PCR and multilocus sequence typing.

Glycerophosphodiester Phosphodiesterase Identified as Non-Reliable Serological Marker for Borrelia miyamotoi Disease.

The relapsing fever group Borrelia miyamotoi is an emerging tick-borne pathogen. Diagnosis of infection is currently mainly based on serological methods detecting antibodies against B. miyamotoi glycerophosphodiester phosphodiesterase (GlpQ). Here, we scrutinized the reliability of GlpQ as a diagnostic marker and compared the seroprevalence in different study populations and by applying various immunoblotting methods. Antibodies were detected in the sera of 7/53 hunters and in 1/11 sera of Lyme neuroborreliosis patients. Furthermore, 17/74 sera of persons with high concentrations of anti-Borrelia burgdorferi sensu lato (α-Bbsl) antibodies reacted strongly with B. miyamotoi GlpQ in immunoblots. The B. miyamotoi GlpQ seroprevalence was 7/50 in α-Bbsl negative persons. In healthy blood donors from commercial suppliers and from the Austrian Red Cross, seroprevalences were 5/14 and 10/35, respectively. Strikingly, two B. miyamotoi PCR-positive cases from Austria had negative GlpQ serology, indicating poor sensitivity. Finally, when we analyzed sera of dogs, we found α-B. miyamotoi GlpQ antibody seroprevalence in tick-free dogs (n = 10) and in tick-exposed dogs (n = 19) with 2/10 and 8/19, respectively. Thus, our results indicate that GlpQ-based B. miyamotoi serology holds neither specificity nor sensitivity.

Identification and Characterization of "Candidatus Rickettsia Thierseensis", a Novel Spotted Fever Group Rickettsia Species Detected in Austria.

Rickettsia spp. are the second most common pathogens detected in Ixodes ricinus ticks in Austria after Borrelia burgdorferi sensu lato. Species belonging to the spotted fever group (SFG) are the causative agents for tick-borne rickettsiosis across the world. So far, only four SFG Rickettsia spp. were detected in Austria, namely R. helvetica, R. raoultii, R. monacensis and R. slovaca. Here, we describe the identification of a new SFG Rickettsia species detected in an I. ricinus tick. Sequencing of various rickettsial genes revealed a nucleotide sequence similarity of 99.6%, 98.5%, 97.3% and 98.5% to the gltA, ompA, ompB, and sca4 genes, respectively, of known and validated species. Additionally, sequencing of the htrA gene and 23S-5S intergenic spacer region also only showed 99.6% and 99.2%, respectively, similarity to known species. Therefore, and in accordance with current criteria for Rickettsia species discrimination, we hereby describe a new species of the SFG with putative pathogenic potential. We propose the name "Candidatus Rickettsia thierseensis" based on the village Thiersee in the Austrian province of Tyrol, where the carrying tick was found.

Human Borrelia miyamotoi Infection, Austria.

We report a human case of Borrelia miyamotoi infection diagnosed in Austria. Spirochetes were detected in Giemsa-stained blood smears. The presence of B. miyamotoi in the patient's blood was confirmed by PCR, and phylogenetic analysis identified an infection with a strain from Europe.

Lyme Borreliosis with Scalp Eschar Mimicking Rickettsial Infection, Austria.

We report on a patient in Austria with scalp eschar and neck lymphadenopathy. Rickettsial etiology was excluded by culture, PCR, and serologic tests. Borrelia afzelii was identified from the eschar swab by PCR. Lyme borreliosis can mimic rickettsiosis; appropriate tests should be included in the diagnostic workup of patients with eschars.

Francisella tularensis as the cause of protracted fever.

BACKGROUND: Tularemia, a re-emerging, potential life threatening infectious disease, can present itself with nonspecific clinical symptoms including fever, chills and malaise. Taking a detailed history of exposure and a highly raised index of clinical suspicion are necessary to take the appropriate diagnostic and therapeutic steps in this setting. Here, a case report of typhoid tularaemia is presented. CASE PRESENTATION: A 53-year old male forester and farmer with protracted fever, abdominal pain, diarrhoea and loss of weight, who experienced productive cough and a pulmonary infiltrate later in the course of disease, was admitted for further investigation. Tularaemia was suspected only owing to history and confirmed by serologic testing more than three weeks after the beginning of the symptoms. The initial antibiotic therapy with ceftriaxone/doxycycline was switched to ciprofloxacin, resulting in the resolution of fever and symptoms. CONCLUSION: Tularaemia has to be considered as a differential diagnosis in febrile patients, even more in cases with protracted fever. Since tularaemia is expanding geographically, involving more animal hosts and causing larger outbreaks, clinicians have to be aware of this potentially fatal disease.

Molecular diagnosis of autochthonous human anaplasmosis in Austria - an infectious diseases case report.

BACKGROUND: The diagnosis of human anaplasmosis remains elusive and is probably often missed. This case report highlights the efficacy of molecular diagnostic techniques. CASE PRESENTATION: We would like to report the case of a 74-year-old man who was admitted to hospital because of a high fever, marked chills, transient diplopic images and vertigo, 6 weeks after multiple tick bites. The laboratory results showed mild anemia, marked thrombocytopenia and leukopenia and a moderately elevated C-reactive protein. The initial serology seemed to indicate an active infection with Borrelia spp., and Anaplasma phagocytophilum was detected in peripheral blood by polymerase chain reaction (PCR) and subsequent sequencing. The patient received intravenous ceftriaxone for 14 days and oral doxycycline for 4 weeks and made a fast and complete recovery. CONCLUSIONS: While human anaplasmosis has been reported very rarely in Austria, it should be considered as a differential diagnosis in febrile patients with low leukocyte and platelet counts with elevated levels of C-reactive protein after exposure to tick bites. Molecular detection of A. phagocytophilum is the technique of choice allowing rapid and reliable diagnosis.

Chlamydia trachomatis serovars in urogenital and ocular samples collected 2014-2017 from Austrian patients.

Infection of humans with Chlamydia trachomatis, a bacterial pathogen with a unique intracellular replication cycle, may cause a variety of clinical manifestations. These are linked to various serovars of the pathogen; trachoma to serovars A-C, oculogenital infections to serovars D-K, and lymphogranuloma venereum to serovars L1-L3. Nineteen serovars are known as human pathogens. The aim of the study was to determine the serovars of 401 C. trachomatis DNA positive extracts from original clinical specimens of patients in Austria including cervical and urethral swabs, urine, genital secretions and conjunctival swabs - collected from 2014 to 2017. Sequence analysis of the omp1 gene, encoding major outer-membrane protein was performed on each sample. In 50.1% of samples serovar E was identified and serovars F, D/Da and G/Ga were found in 16.2%, 9.7% and 9.0%, respectively. Remaining serovars were J (6.0%), K (4.7%), H (2.7%), B/Ba (1.0%), and I/Ia (0.5%). In 19 patients follow up samples could be tested. The majority of C. trachomatis serovars were associated with urogenital tract infections (D-K), however, one of them - serovar B/Ba - is linked to both, ocular and genital tract infection.

Severe Myasthenic Manifestation of Leptospirosis Associated with New Sequence Type of Leptospira interrogans.

We report the rapid development of a myasthenic crisis as the first-time manifestation of myasthenia gravis. The symptoms developed in the course of acute leptospirosis associated with a new sequence type of Leptospira interrogans. Antibiotic treatment led to rapid amelioration of myasthenia.