Gregory Spanakos - Academia.edu (original) (raw)

Papers by Gregory Spanakos

During the last three years Greece is experiencing the emergence of West Nile virus (WNV) epidemi... more During the last three years Greece is experiencing the emergence of West Nile virus (WNV) epidemics. Within this framework, an integrated surveillance and control programme (MALWEST project) with thirteen associate partners was launched aiming to investigate the disease and suggest appropriate interventions. One out of seven work packages of the project is dedicated to the State of the Art report for WNV. Three expert working groups on humans, animals and mosquitoes were established. Medical databases (PubMed, Scopus) were searched together with websites: e.g., WHO, CDC, ECDC. In total, 1,092 relevant articles were initially identified and 258 of them were finally included as references regarding the current knowledge about WNV, along with 36 additional sources (conference papers, reports, book chapters). The review is divided in three sections according to the fields of interest: (1) WNV in humans (epidemiology, molecular characteristics, transmission, diagnosis, treatment, prevention, surveillance);

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, Jan 3, 2015

Visceral leishmaniasis (VL) is re-emerging in endemic areas. The epidemiological, clinical, labor... more Visceral leishmaniasis (VL) is re-emerging in endemic areas. The epidemiological, clinical, laboratory, and treatment outcome characteristics in a large cohort of VL patients is described herein. The cases of 67 VL patients (57% male, mean age 56 years) treated in two Greek hospitals over the last 7 years were identified and evaluated retrospectively. Forty-six percent of patients reported contact with animals. Seventeen patients (25%) were immunocompromised, and 22% were co-infected with another pathogen. Sixty-four percent of patients had fever, 57% had weakness, 37% had sweats, 21% had weight loss, and 13% had a dry cough, while 6% developed haemophagocytic syndrome. The median duration of symptoms was 28 days. Fifty-eight percent of patients had splenomegaly, 49% had hepatomegaly, and 36% had lymphadenopathy. The diagnosis was established by positive PCR in peripheral blood (73%) and/or bone marrow specimens (34%). Sixty-one patients (91%) received liposomal amphotericin (L-AMB)...

Parasitology Research, 2015

Here, we present the first time findings regarding the occurrence of Cryptosporidium and Giardia ... more Here, we present the first time findings regarding the occurrence of Cryptosporidium and Giardia in sewage waters and the first molecular characterization of Cryptosporidium species in Greece. Biological treatment plants from three regions in Greece have been investigated. The detection of Cryptosporidium oocysts was by modified Ziehl-Neelsen acid fast (MZN-AF) and by immunofluorescence microscopy (IFT) for Cryptosporidium and Giardia (oo)cysts, whereas nested PCR based on the SSU rDNA assay was used for molecular detection of Cryptosporidium followed by sequencing for the genetic characterization of the species. In total, 73 samples (37 raw sewage samples and 38 of treated water samples) were collected and analyzed. Of the 73 water samples, 4 samples were Cryptosporidium-positive by IFT and staining, 12 samples were Cryptosporidium-positive by nested PCR; 9 samples were Giardia-positive by IFT. We showed that Cryptosporidium cysts are found both in the input and the discharge of the biological treatment plants. Molecular characterization of Cryptosporidium based on the small subunit ribosomal DNA gene resulted in the determination of Cryptosporidium parvum and Cryptosporidium muris Greek isolates. This is the first report of Cryptosporidium and Giardia occurrence in wastewaters and the first molecular identification of Cryptosporidium species in Greek environments. As the treated water is used for irrigation, or it is discharged into the sea, our findings indicate that biological treatment facilities constitute a possible risk for public health because the related species are prevalent in humans; the results invite for further epidemiological investigations to evaluate the real public health risk in Greece.

Journal of medical entomology, 2006

The presence of Aedes albopictus (Skuse) was recently confirmed for the first time in northwester... more The presence of Aedes albopictus (Skuse) was recently confirmed for the first time in northwestern Greece. This location is within the distribution range of a morphologically similar species, Aedes cretinus Edwards, and is a potentially favorable region for the reintroduction of Aedes aegypti (L.). It was thus compelling to use methods in addition to morphology-based keys to correctly identify specimens badly damaged, rubbed, or otherwise altered in their external characteristics. It was decided to use molecular techniques as a novel and reliable method for differentiating the three Stegomyia species. The nuclear internal transcribed spacer 2 (ITS2) fragments from morphologically identified Ae. albopictus and Ae. cretinus specimens were amplified, and their sequences were compared with those in GenBank for Ae. albopictus, Ae. cretinus, and Ae. aegypti. Also, mitochondrial cytochrome oxidase I (COI) fragments were amplified for Ae. albopictus and Ae. cretinus (so far not available in...

Veterinary Dermatology, 2010

Histological lesions and the presence of Leishmania spp. amastigotes in claw tissues were investi... more Histological lesions and the presence of Leishmania spp. amastigotes in claw tissues were investigated in 40 dogs with leishmaniosis, with (16/40--group A) or without (24/40--group B) generalized onychogryphosis. Following euthanasia, the entire third phalanx with intact claw was amputated, formalin fixed, decalcified in a formic acid solution, embedded in paraffin, sectioned longitudinally and stained with haematoxylin and eosin, and acid orcein-Giemsa. Nested polymerase chain reaction (PCR) was used for the detection of Leishmania amastigotes. Lichenoid mononuclear infiltration (all dogs in group A, 21 of 24 dogs in group B), basal keratinocyte vacuolation (nine of 16 dogs in group A, 15 of 24 dogs in group B) and dermoepidermal clefting (13 of 16 dogs in group A, 18 of 24 dogs in group B) were the most prominent histopathological findings. There was no difference in the frequency and severity of these lesions between the two groups. Leishmania amastigotes could not be visualized in the dermis of any of the H&amp;amp;amp;amp;amp;amp;amp;amp;E sections, but their presence was demonstrated by nested PCR in three of 16 dogs in group A and two of 24 dogs in group B. However, the frequency of positive nested PCRs was not significantly different between the two groups. In conclusion, claw histopathology in symptomatic dogs with leishmaniosis, either with or without onychogryphosis is mainly characterized by mononuclear lichenoid dermatitis with or without interface dermatitis and dermoepidermal clefting, and is not accompanied by substantial local parasitism.

The Veterinary Journal, 2010

Canine leishmaniosis (CL) is a common systemic parasitic disease that is endemic in many Mediterr... more Canine leishmaniosis (CL) is a common systemic parasitic disease that is endemic in many Mediterranean countries including Greece. The immune reaction to the parasite is critical to the outcome of the infection and the response to treatment. Some studies have shown a reduction of circulating CD4+ T cells and of the CD4+/CD8+ ratio in dogs with CL and these changes normalised following treatment with meglumine antimoniate or amphotericin B. Allopurinol is used as a monotherapy for the chronic treatment of CL. The aim of the present study was to determine the circulating CD4+ and CD8+ T lymphocyte numbers and the CD4+/CD8+ ratio in 19 dogs diagnosed with CL before and after prolonged allopurinol monotherapy (18 months). A significant decrease in circulating CD4+ T cells was observed in dogs with CL before treatment. Prolonged allopurinol monotherapy improved the number of circulating CD4+ T cells, but did not restore their number to within the normal range.

Parasitology International, 2002

Dirofilariasis is a parasitic disease, which if treated inappropriately due to misdiagnosis, can ... more Dirofilariasis is a parasitic disease, which if treated inappropriately due to misdiagnosis, can cause unwanted complications particularly when the infection is located in the breast. The numerous obstacles that can cause misdiagnosis of dirofilariases by standard morphological procedures prompted the development of a Dirofilaria repens-specific direct polymerase chain reaction (PCR)-based diagnostic approach using freshly infected dog blood. Reliable amplification of nematode DNA from formalin-fixed infected human specimens by this method is only possible from relatively fresh biological material, preserved in the fixative for up to 20 days. We report here our first case of dirofilariasis since the development of PCR genotyping, where the pathogen was morphologically unrecognizable and the diagnosis was based exclusively on DNA amplification. We complete our methodological contribution to the clinical laboratory diagnosis of dirofilariasis by presenting two more cases, where the primary genotypic assignment of infection by D. repens was further confirmed by conventional morphological means. ᮊ

Parasitology International, 1999

Diagnosis of human infection by Dirofilaria repens, depends mainly on microscopic evaluation of t... more Diagnosis of human infection by Dirofilaria repens, depends mainly on microscopic evaluation of tissue cross-sections and the macroscopic characteristics of the worm. Tissue degeneration andror poor specimen preparation practices however, often render many cases of subcutaneous dirofilariasis elusive to such morphological diagnostic approaches. The early PCR protocols, developed to satisfy these complex diagnostic needs, failed to amplify dirofilariae DNA from formalin preserved material. To overcome these difficulties, we developed an improved PCR protocol using a set of primers designed to amplify a rather stable, highly repetitive D. repens-specific genomic DNA target. We report the performance of this protocol with a large variety of dirofilariae infected DNA specimens, including those extracted from formalin preserved biological material for up to 20 days. Our findings support its potential application to routine clinical diagnosis. ᮊ

Medical and Veterinary Entomology, 2007

Specimens belonging to the Anopheles maculipennis complex were collected as larvae or resting adu... more Specimens belonging to the Anopheles maculipennis complex were collected as larvae or resting adults from May 2003 to November 2004 in the area of the Athens 2004 Olympic Rowing Centre in Schinias, Attiki, Greece, and identified by morphological and molecular analyses. Of the 201 specimens collected, 199 were found to be Anopheles sacharovi Favre and two were An. maculipennis Meigen s.s. on the basis of similarity to published sequence data for the rDNA internal transcribed spacer (ITS2) region and the mitochondrial cytochrome c oxidase I gene (COI). Sequence data from a number of specimens were obtained for both genes and compared with corresponding GenBank data derived from diverse geographical areas. A high degree of homology in ITS2 sequences was found in both species, ranging from 99.5% to 100% in An. sacharovi and 99.4% to 100% in An. Maculipennis , with no intraspecific variation in either of the two species in our study. The degree of homology in the COI sequences was 94.8 -99.8% in An. sacharovi and 95.0 -99.8% in An. maculipennis. The 522-bp fragment produced a rather high degree of intrapopulation polymorphism for An. sacharovi, generating nine different haplotypes, five of which were singletons. Intraspecific variation for these sequences ranged from 0.2% to 1.4%, but was much lower (0.77%) for the two An. maculipennis sequences. These findings represent the first characterization of the An. maculipennis complex in the area of Schinias.

Annals of Tropical Medicine and Parasitology, 2003

The ability to detect and differentiate between Plasmodium falciparum and P. vivax is of great im... more The ability to detect and differentiate between Plasmodium falciparum and P. vivax is of great importance for the routine laboratory diagnosis of malaria, donor-blood screening and epidemiological studies. Most PCR-based methods for the discrimination of these two species require nested protocols or an additional hybridization reaction, leading to high labour costs and long turn-around times. A simple, time-effective and yet sensitive and specific technique, based on a multiplex PCR, has now been developed for the simultaneous detection and differentiation of P. falciparum and P. vivax in blood samples. Compared with the 'gold standard' of microscopy, this method had a sensitivity and specificity of 100%, with a detection limit of just one P. falciparum or three P. vivax parasites/ml blood. been characterized, species-specific regions of these genes were exploited in developing Reprint requests to: E. Patsoula.

Parasit …, Jan 1, 2008

Blastocystis is a prevalent enteric protozoan that infects a variety of vertebrates. Infection wi... more Blastocystis is a prevalent enteric protozoan that infects a variety of vertebrates. Infection with Blastocystis in humans has been associated with abdominal pain, diarrhea, constipation, fatigue, skin rash, and other symptoms. Researchers using different methods and examining different patient groups have reported asymptomatic infection, acute symptomatic infection, and chronic symptomatic infection. The variation in accounts has lead to disagreements concerning the role of Blastocystis in human disease, and the importance of treating it. A better understanding of the number of species of Blastocystis that can infect humans, along with realization of the limitations of the existing clinical laboratory diagnostic techniques may account for much of the disagreement. The possibility that disagreement was caused by the emergence of particular pathogenic variants of Blastocystis is discussed, along with the potential role of Blastocystis infection in irritable bowel syndrome (IBS). Findings are discussed concerning the role of protease-activated receptor-2 in enteric disease which may account for the presence of abdominal pain and diffuse symptoms in Blastocystis infection, even in the absence of fever and endoscopic findings. The availability of better diagnostic techniques and treatments for Blastocystis infection may be of value in understanding chronic gastrointestinal illness of unknown etiology.

Hybridoma

Epirubicin is an anthracyclinic antibiotic that has been increasingly used in the treatment of a ... more Epirubicin is an anthracyclinic antibiotic that has been increasingly used in the treatment of a variety of malignancies. A hybridoma producing monoclonal antibody (MAb) against the drug was obtained by cell fusion. The MAb is of the IgM isotype and has an affinity constant of 1.4 x 10(-7) M. Inhibition analysis showed that the antibody recognizes an epitope related to the C 4'-hydroxyl group in the amino sugar moiety, distinguishing epirubicin from the closely related doxorubicin. Since the precise mechanism of anthracycline action as well as its immunomodulating effects are still under scrutiny, powerful tools for their study are clearly needed. Moreover, this MAb can be useful in monitoring the levels of epirubicin in treated patients, as well as for the construction of bispecific antibodies in tumor-targeting immunotherapy.

Schizophrenia research, Jan 15, 2001

A number of immunological parameters were studied in 82 DSM-III-R diagnosed schizophrenic patient... more A number of immunological parameters were studied in 82 DSM-III-R diagnosed schizophrenic patients (53 first drug-naive and 29 medicated chronic patients) as well as 62 healthy blood donors. The serum levels of interleukin-2 (IL-2), interleukin-1 beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) were measured and correlated with cellular immunity, as assessed by the autologous mixed lymphocyte reaction (AMLR). T lymphocyte subsets were also examined. The above immune parameters were reassessed in a subgroup of 11 first-episode, drug-naive patients 1month after neuroleptic medication. IL-2 serum levels were significantly lower, and IL-1beta and TNF-alpha were significantly higher in schizophrenic patients compared with healthy donors (P<0.001); no significant difference was observed between the two patient groups (medicated and not medicated). Abnormal cytokine serum levels were associated with decreased AMLR responses in vitro. Increased percentages of activated CD4+ a...

British journal of cancer, 1997

The present study investigated the ability of supernatants collected from cultures of healthy don... more The present study investigated the ability of supernatants collected from cultures of healthy donor-derived peripheral blood mononuclear cells (HD-PBMCs) stimulated with anti-CD3 monoclonal antibody (MAb) (allogeneic CD3 supernatants; ACD3S) to induce, upon brief exposure, tumour-reactive cytotoxic lymphocytes in cancer patients' PBMCs. ACD3S enhanced natural killer (NK) and lymphokine-activated killer (LAK) cell-mediated cytotoxicity. ACD3S contained increased levels of interleukins (IL) 1, 2, 6, 7 and 12, as well as of granulocyte-macrophage colony-stimulating factor (GM-CSF), gamma-interferon (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha). MAbs against these cytokines significantly reduced the ACD3S-induced cytotoxicity. ACD3S-induced cytotoxicity was not inhibited by anti-CD4, CD8 and MHC class I MAbs, but was markedly reduced in the presence of MAb against CD18. In contrast to HD-PBMC, ACD3S derived from cancer patients' lymphocytes exhibited lower levels of t...

Zoonoses and Public Health, 2010

Leishmania infantum and Leishmania tropica are the species responsible for visceral leishmaniasis... more Leishmania infantum and Leishmania tropica are the species responsible for visceral leishmaniasis and cutaneous leishmaniasis respectively. In Greece, both diseases are endemic. The dog is considered the main reservoir of L. infantum, whereas the role of other animals for both L. infantun and L. tropica is unknown. Spleens from wild Rattus norvegicus, live trapped in Greece, were examined for the presence of Leishmania parasites by PCR. Out of 16 samples examined, only one was found positive for L. infantum with scant amount of parasitic DNA present. This is the first documented case of detection of L. infantum in R. norvegicus in Greece. The results of this preliminary study indicate that R. norvegicus is unlikely to be a reservoir for Leishmania parasites in Greece.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008

The aim of this study was to develop a simple, low-cost method for the detection and species diff... more The aim of this study was to develop a simple, low-cost method for the detection and species differentiation of Leishmania directly from clinical samples, for routine use in a parasitology laboratory. A total of 87 samples was used, including 60 peripheral blood, seven bone marrow and 17 skin lesion material samples, derived from Greek patients with visceral or cutaneous leishmaniasis, and three reference strains. PCR was performed using primers designed to amplify the internal transcribed spacer 1 (ITS1) region of the rRNA gene. Identification of the Leishmania species studied was achieved by digestion with a single restriction endonuclease (RFLP), single-strand conformational polymorphism (SSCP) and DNA sequencing of the PCR-generated fragments. Typing identified all visceral and one cutaneous leishmaniasis strains as L. infantum, twelve of the cutaneous leishmaniasis strains as L. tropica and four as L. major. The described PCR method proved efficient for the detection of pathogenic Leishmania species in various clinical samples, most importantly in peripheral blood samples. Furthermore, PCR followed by a simple RFLP using a single restriction endonuclease was capable of identifying all Leishmania species commonly encountered in Greece.

Parasitology International, 2006

Amoebae belonging to the genus Acanthamoeba are potentially pathogenic to humans, causing mainly ... more Amoebae belonging to the genus Acanthamoeba are potentially pathogenic to humans, causing mainly amoebic keratitis. Pathogenic ability of the 15 known Acanthamoeba genotypes is under investigation. We report that four out of five cases of amoebic keratitis studied in Greece, present T4 sequence type, while the remaining one presents T5 sequence type (Acanthamoeba lenticulata), which is the second most frequent genotype found among environmental samples. Thus, it is confirmed, for the first time to our knowledge, that A. lenticulata can cause keratitis. However the reason that it is under represented in clinical samples compared to environmental ones is unknown.

Parasites & Vectors, 2008

Molecular and Cellular Probes, 2011

Human infection with the parasitic nematode Enterobius vermicularis occurs worldwide, particularl... more Human infection with the parasitic nematode Enterobius vermicularis occurs worldwide, particularly in children. Although its prevalence may exceed 35% in some parts of the world, molecular studies of E. vermicularis in humans are limited. The aim of the present study was to investigate the genetic variation within E. vermicularis in a human population. For this purpose, 77 adhesive tape samples taken from Greek children infested with E. vermicularis were tested. New primers were designed to amplify a segment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of E. vermicularis from adhesive tape samples. Thirty-six amplicons were sequenced and eleven different haplotypes were identified. All sequences clustered within the type previously characterized (type B), only reported to date from captive chimpanzees. To the best of our knowledge, this is the first study of E. vermicularis genotypes from a human population.