167 research outputs found
Serological evidence of Midichloria mitochondrii circulation in humans parasitized by I. ricinus in Germany and development of a marker for tick bite
The tick Ixodes ricinus transmits several microorganisms of medical and veterinary importance. Midichloria mitochondrii (order Rickettsiales; family Midichloriaceae) is an intracellular symbiont present in the ovaries and salivary glands of 100% of adult I. ricinus females (Sassera et al., 2008) and is transmitted to the vertebrate host during the tick bite (Mariconti et al., 2012; Bazzocchi et al., 2013) despite its infective role is not demonstrated.In this experimental study, a total of 324 human from different areas of Germany were analysed in order to investigate the seropositivity against the flagellar FliD protein of M. mitochondrii using an ELISA approach. Fifty sera were collected from patients living in non-endemic areas and used as negative controls while 274 sera were obtained from subjects exposed to tick bite and suffering from several symptoms referred to tick borne diseases and collected at the BCA clinic in Augsburg.Since the positivity for the spirochete Borrelia burgdorferi transmitted by I. ricinus is indicative for the tick bite, we considered also this additional information.The obtained results showed that 82 out of 274 sera were positive to M. mitochondrii and 42 out of 175 sera of subjects negative to B. burgdorferi were positive to M. mitochondrii to confirm the good property of FliD protein as a tick bite marker. However, the high number (133 out of 274) of subjects parasitized by I. ricinus but negative to both bacteria prompted us to detect new more suitable I. ricinus/M. mitochondrii antigenic proteins to use as markers for tick bite. For this purpose, three I. ricinus proteins and one surface protein of M. mitochondrii were selected and 12 synthetic peptides were designed in order to set-up a new ELISA test for investigating the exposure of humans and animals to this tick species
Detection of a novel bacterium of the genus Midichloria (family Midichloriaceae) in avian-borne Hyalomma marginatum ticks and their trans-Saharan migratory hosts
Introduction: Ticks are haematophagous ectoparasites of vertebrates habitually parasitizing avian species, which may contribute to tick dispersal across continents during migrations (Hasle 2013; Altizer et al., 2011). Midichloria bacteria can be transmitted to the vertebrate host during the tick bite (Bazzocchi et al., 2013; Serra et al., 2018). Although many avian species are common hosts of ticks harbouring Midichloria (e.g. Ixodes, Hyalomma), the circulation of this bacterium in birds has never been investigated. The aims of this study are: 1) evaluate the presence of Midichloria DNA in H. marginatum ticks and blood collected from trans-Saharan migratory birds; 2) quantify Midichloria bacteria in ticks through a novel quantitative PCR (qPCR).Material and methods: A total of 256 H. marginatum ticks and 97 blood samples were collected from three different migratory species (Phoenicurus phoenicurus, Saxicola rubetra and Sylvia communis) on Ventotene Island (Central Italy) and DNAs were extracted. A nested-PCR targeting the 16S rRNA gene of Midichloria was used to detect bacterial presence. Subsequently, primers targeting the gyrB gene of Midichloria and the cal gene of H. marginatum were designed and used in a qPCR for Midichloria quantification. Results were expressed as gyrB/cal copy numbers ratio.Results and discussion: 94% of Hyalomma ticks harbored DNA of Midichloria belonging to the monophylum associated with ticks, while the bacterial DNA was detected in 44.3% of blood samples. Furthermore, engorged ticks showed significantly higher bacteria load than unengorged ticks (Table 1; Wilcoxon sum-rank test: z=3.14; p=0.0017), similarly to what has been observed for M. mitochondrii in I. ricinus ticks.Conclusions: This work provides evidence for the presence of circulating Midichloria DNA in long-distance migratory birds, suggesting an enhanced worldwide spread of these bacteria across haematophagous ectoparasite populations. Future studies are necessary to increase the knowledge of Midichloria role in the biology of this tick species
Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT.
Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones
Molecular screening for Midichloria bacteria in hard and soft ticks (Acari: Ixodida).
Ticks can harbor complex and highly variable microbial communities. Among these microorganisms,there are important pathogens of humans and animals that can be transmitted through the blood meal.Less is known about the other members of the microbial community of Ixodida, those that do not causeovert diseases. Among these, Midichloria mitochondrii, symbiont of the tick Ixodes ricinus, is the firstdescribed member of the family Midichloriaceae, order Rickettsiales. This bacterium is present in 100%females and is vertically transmitted (Sassera, 2008). The possibility of horizontal transmission issuggested by serological and molecular analyses showing positivity of mammalian blood and sera to M.mitochondrii (Mariconti, 2012; Bazzocchi, 2013). However, its role is still unknown. Recent reports areexpanding the view of this family, now including bacteria of great biological and medical interest,indicating a widespread distribution with an increasing range of hosts, with ticks being stronglyrepresented (Epis, 2008).Here we present a molecular screening of 17 tick species (for a total of 92 individuals), detecting andquantifying bacteria closely related to M. mitochondrii in seven of them, including the first report of amidichloriacea in a soft tick species, Ornithodoros maritimus. Based on sequence identity andphylogenetic analysis we propose that these bacteria could constitute the genus Midichloria. Theperformed screening highlights different prevalence levels in different tick species including one, Ixodesaulacodi, where the bacteria is present in all examined individuals, like in I. ricinus. This result promptsus to hypothesize different roles of Midichloria bacteria in different tick species
Obligatory symbiotic Wolbachia endobacteria are absent from Loa loa
BACKGROUND: Many filarial nematodes harbour Wolbachia endobacteria. These endobacteria are transmitted vertically from one generation to the next. In several filarial species that have been studied to date they are obligatory symbionts of their hosts. Elimination of the endobacteria by antibiotics interrupts the embryogenesis and hence the production of microfilariae. The medical implication of this being that the use of doxycycline for the treatment of human onchocerciasis and bancroftian filariasis leads to elimination of the Wolbachia and hence sterilisation of the female worms. Wolbachia play a role in the immunopathology of patients and may contribute to side effects seen after antifilarial chemotherapy. In several studies Wolbachia were not observed in Loa loa. Since these results have been doubted, and because of the medical significance, several independent methods were applied to search for Wolbachia in L. loa. METHODS: Loa loa and Onchocerca volvulus were studied by electron microscopy, histology with silver staining, and immunohistology using antibodies against WSP, Wolbachia aspartate aminotransferase, and heat shock protein 60. The results achieved with L. loa and O. volvulus were compared. Searching for Wolbachia, genes were amplified by PCR coding for the bacterial 16S rDNA, the FTSZ cell division protein, and WSP. RESULTS: No Wolbachia endobacteria were discovered by immunohistology in 13 male and 14 female L. loa worms and in numerous L. loa microfilariae. In contrast, endobacteria were found in large numbers in O. volvulus and 14 other filaria species. No intracellular bacteria were seen in electron micrographs of oocytes and young morulae of L. loa in contrast to O. volvulus. In agreement with these results, Wolbachia DNA was not detected by PCR in three male and six female L. loa worms and in two microfilariae samples of L. loa. CONCLUSIONS: Loa loa do not harbour obligatory symbiotic Wolbachia endobacteria in essential numbers to enable their efficient vertical transmission or to play a role in production of microfilariae. Exclusively, the filariae cause the immunopathology of loiasis is patients and the adverse side effects after antifilarial chemotherapy. Doxycycline cannot be used to cure loiais but it probably does not represent a risk for L. loa patients when administered to patients with co-infections of onchocerciasis
Wolbachia surface protein induces innate immune responses in mosquito cells
BACKGROUND: Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. RESULTS: Here we show that recombinant Wolbachia Surface Protein (WSP) stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. CONCLUSIONS: We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae) while a milder elicitor in a naturally-infected species (Aedes albopictus). Since the WSP of a mosquito non-native (nematode) Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus
The Genome Sequence of "Candidatus Fokinia solitaria": Insights on Reductive Evolution in Rickettsiales
"Candidatus Fokinia solitaria" is an obligate intracellular endosymbiont of a unicellular eukaryote, a ciliate of the genus Paramecium. Here, we present the genome sequence of this bacterium and subsequent analysis. Phylogenomic analysis confirmed the previously reported positioning of the symbiont within the "Candidatus Midichloriaceae" family (order Rickettsiales), as well as its high sequence divergence from other members of the family, indicative of fast sequence evolution. Consistently with this high evolutionary rate, a comparative genomic analysis revealed that the genome of this symbiont is the smallest of the Rickettsiales to date. The reduced genome does not present flagellar genes, nor the pathway for the biosynthesis of lipopolysaccharides (present in all the other so far sequenced members of the family "Candidatus Midichloriaceae") or genes for the Krebs cycle (present, although not always complete, in Rickettsiales). These results indicate an evolutionary trend toward a stronger dependence on the host, in comparison with other members of the family. Two alternative scenarios are compatible with our results; "Candidatus Fokinia solitaria" could be either a recently evolved, vertically transmitted mutualist, or a parasite with a high host-specificity
Congenital cystic adenomatoid malformation of the lung associated with bronchial atresia involving a different lobe in an adult patient: a case report
<p>Abstract</p> <p>Introduction</p> <p>Congenital cystic adenomatoid malformation of the lung is an uncommon cause of respiratory distress in neonates and babies. The disorder is usually diagnosed in the neonatal period and the first two years of life. This anomaly has been described in association with bronchopulmonary sequestration, extralobar intra-abdominal sequestration or bronchial atresia in live and stillborn babies. It is rarely encountered in adults, in whom the diagnosis is made incidentally from mass lesion features seen on chest radiographs. The oldest patients recorded with this malformation have been about 35 years old, and only 10% of primary diagnoses are made after the first year of life. Delayed diagnosis can be related to infection or serendipitous discovery.</p> <p>Case presentation</p> <p>We describe the radiological findings of a 34-year-old Caucasian woman with a clinical history of recurrent pneumonia, intermittent anterior pleuritic chest pain and haemoptysis. Congenital cystic adenomatoid malformation of the lung associated with bronchial atresia involving a different lobe was discovered.</p> <p>Conclusion</p> <p>Although rare in adults, congenital cystic adenomatoid malformation should be suspected in adult patients who suffer from recurrent or persistent non-productive coughs. The discovery of an association of congenital cystic adenomatoid malformation with bronchial atresia in adulthood is rare but possible, even in different lobes.</p
A Novel High Discriminatory Protocol for the Detection of Borrelia afzelii, Borrelia burgdorferi Sensu Stricto and Borrelia garinii in Ticks
Bacteria of the Borrelia burgdorferi sensu lato complex are the causative agents of Lyme borreliosis (LB). Even if the conventional diagnosis of LB does not rely on the species itself, an accurate species identification within the complex will provide a deepened epidemiological scenario, a better diagnosis leading to a more targeted therapeutic approach, as well as promote the general public's awareness. A comparative genomics approach based on the 210 Borrelia spp. genomes available in 2019 were used to set up three species-specific PCR protocols, able to detect and provide species typing of Borrelia afzelii, Borrelia burgdorferi sensu stricto (s.s.) and Borrelia garinii, the three most common and important human pathogenic Lyme Borrelia species in Europe. The species-specificity of these protocols was confirmed on previously identified B. afzelii, B. burgdorferi s.s. and B. garinii specimens detected in Ixodes ricinus samples. In addition, the protocols were validated on 120 DNA samples from ticks collected in Sweden, showing 88% accuracy, 100% precision, 72% sensitivity and 100% specificity. The proposed approach represents an innovative tool in epidemiological studies focused on B. burgdorferi s.l. occurrence in ticks, and future studies could suggest its helpfulness in routine diagnostic tests for health care
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