Tsetse flies are well-known vectors of trypanosomes pathogenic for humans and livestock. For these strictly blood-feeding viviparous flies, the host blood should be the only source of nutrients and liquids, as well as any exogenous microorganisms colonising their intestine. Here we describe the unexpected finding of several monoxenous trypanosomatids in their gut. In a total of 564 individually examined Glossina (Austenia) tabaniformis (Westwood) (436 specimens) and Glossina (Nemorhina) fuscipes fuscipes (Newstead) (128 specimens) captured in the Dzanga-Sangha Protected Areas, Central African Republic, 24 (4.3%) individuals were infected with monoxenous trypanosomatids belonging to the genera Crithidia Léger, 1902; Kentomonas Votýpka, Yurchenko, Kostygov et Lukeš, 2014; Novymonas Kostygov et Yurchenko, 2020; Obscuromonas Votýpka et Lukeš, 2021; and Wallacemonas Kostygov et Yurchenko, 2014. Moreover, additional 20 (3.5%) inspected tsetse flies harboured free-living bodonids affiliated with the genera Dimastigella Sandon, 1928; Neobodo Vickerman, 2004; Parabodo Skuja, 1939; and Rhynchomonas Klebs, 1892. In the context of the recently described feeding behaviour of these dipterans, we propose that they become infected while taking sugar meals and water, providing indirect evidence that blood is not their only source of food and liquids.
Seven- to eight-week-old rabbits were infected with Eimeria intestinalis Cheissin, 1948, a highly immunogenic coccidium, or Eimeria flavescens Marotel et Guilhon, 1941, which is weakly immunogenic. Immune response was investigated at 7, 14 and 21 days post inoculation (DPI). The level of serum immunoglobulins, lymphocyte proliferation stimulated by parasite antigens and weight of mesenteric lymph nodes (MLN) showed similar dynamics in rabbits inoculated with both coccidia species. The amount of serum IgG and IgM, but not IgA, was increased from 14 DPI. The lymphocytes from MLN of infected animals significantly reacted to stimulation with parasite antigen 14 and 21 DPI and MLN were enlarged at 14 DPI. Thus, both parasite species elicited immune response characterized by these parameters in a similar manner despite of their different immunogenicity. The only apparent difference in the responses was in the percentage of CD8+ lymphocytes in the specific site of parasite development (the last third of the small intestine in E. intestinalis, caecum in E. flavescens), which increased in rabbits infected with E. intestinalis but not with E. flavescens. This parameter reflects the status of local immunity and hence the results suggest that the local reaction plays an important role in induction of protective immunity to coccidia in rabbits.
Parasite life history traits influence the rate of gene flow between populations and the effective population size, both of which determine the levels of genetic variability and the geographic distribution of such variability. In this short review targeted to parasitologists, we summarise how life history traits influence the population genetic structure of parasitic helminths. These organisms are characterised by a wide variety of life cycles and are ecologically different from microparasites, which have been studied in more detail. In order to provide the reader a concise review that illustrates key aspects of the subject matter, we have limited ourselves to studying examples selected for their clarity and relevance., Severo Vázquez-Prieto, Román Vilas, Esperanza Paniagua, Florencio M. Ubeira., and Obsahuje bibliografii
The K13 propeller domain mutation and pfmdr1 amplification have been proposed as useful molecular markers for detection and monitoring of artemisinin resistant Plasmodium falciparum Welch, 1897. Genomic DNA isolates of P. falciparum was extracted from 235 dried blood spot or whole blood samples collected from patients with uncomplicated falciparum malaria residing in areas along the Thai-Myanmar border during 2006-2010. Nested polymerase chain reaction (PCR) and sequencing were performed to detect mutations in K13 propeller domain of P. falciparum at codon 427-709. Pfmdr1 gene copy number was determined by SYBR Green I real-time PCR. High prevalence of pfmdr1 multiple copies was observed (42.5% of isolates). The presence of K13 mutations was low (40/235, 17.2%). Seventeen mutations had previously been reported and six mutations were newly detected. The C580Y was found in two isolates (0.9%). The F446I, N458Y and P574L mutations were commonly detected. Seven isolates had both K13 mutation and pfmdr1 multiple copies. It needs to be confirmed whether parasites harbouring both K13 mutation and pfmdr1 multiple copies and/or the observed new mutations of K13 propeller domain are associated with clinical artemisinin resistance., Papichaya Phompradit, Wanna Chaijaroenkul, Phunuch Muhamad, Kesara Na-Bangchang., and Obsahuje bibliografii
Toxoplasmosis is a potentially fatal complication after hematopoietic cell transplantation (HCT). Pre-transplant seropositivity of graft recipient to Toxoplasma gondii (Nicolle et Manceaux, 1908) is an important factor for disease reactivation after HCT. As toxoplasmosis epidemiology varies all over the world, we performed a Polish nationwide retrospective cohort study to determine the seroprevalence of toxoplasmosis in donors and pediatric allogeneic and autologous HCT recipients and the incidence of clinically evident toxoplasmosis in this patient group. Polish adult donors had higher anti-T. gondii seroprevalence than Polish pediatric donors (28% vs 8%; OR = 4.4; p = 0.02) and allo-HCT recipients (28% vs 17%; OR = 1.9; p = 0.01). Clinically apparent disease occurred in 1% of allo-HCT recipients: it was diagnosed by PCR as cerebral and/or ocular toxoplasmosis and successfully treated with antiprotozoal therapy. Regarding current practice, no prospective screening for infection of T. gondii in pediatric HCT centres is being performed, but, vast majority of HCT pediatric patients are receiving anti-T. gondii active prophylaxis. Since pre-HCT T. gondii serology was not assessed in all HCT; recipients, we propose this test should be a standard practice. Standardisation of management with infection of T. gondii in children after HCT is needed.
Entamoeba moshkovskii Tshalaia, 1941 is prevalent in developing countries and it is considered to be primarily a free-living amoeba, which is morphologically indistinguishable, but biochemically and genetically different from the human infecting, pathogenic Entamoeba histolytica Schaudinn, 1903. The pathogenic potential of this organism is still under discussion. Entamoeba moshkovskii in human stool samples has been reported in different countries such as the United States, Italy, Australia, Iran, Turkey, Bangladesh, India (Pondicherry), Indonesia, Colombia, Malaysia, Tunisia, Tanzania and Brazil, but no data are available about the occurrence of E. moshkovskii in farm animals. This study provides data on the occurrence of E. moshkovskii in pigs in a total of 294 fresh faecal samples collected from five different regions in Kolkata, West Bengal, India. Stool samples were tested by nested PCR using primers targeting SSU rDNA of E. moshkovskii. The amplified PCR products were further confirmed by RFLP technique. Purified nested PCR products were also sequenced and identified via BLAST program run on the NCBI website to confirm species along with their genetic characteristics of the E. moshkovskii isolates. Overall 5.4 % samples were identified as E. moshkovskii positive. Results of this study demonstrate that swine can host E. moshkovskii and should be considered as a potential natural reservoir for E. moshkovskii. However, the occurrence of E. moshkovskii infection in pigs was not statistically associated with their faecal consistency, sex and developmental stage.
Microcercous cercariae possess a very short tail and are produced by digenean species of several families including medically important species, such as members of the genera Paragonimus Braun, 1899, Nanophyetus Chapin, 1927 and Troglotrema Odhner, 1914. During our survey of cercariae of Paragonimus spp. in Vietnam, we found microcercous cercariae from ten (0.29%) out of 3,400 snails of Triculinae gen. sp. 2. They were morphologically and molecularly analysed for species identification. The molecular analysis, based on ITS2 sequences, revealed two distinct species: four specimens were identical to Paragonimus proliferus Hsia et Chen, 1964 (Paragonimidae Dollfus, 1939), and the other six specimens were closest to members of the family Troglotrematidae Odhner, 1914 and were temporarily named Troglotrematidae gen. sp. Morphologically, cercariae of the two species found in this study are similar to each other in their gross characteristics but can be distinguished from one another by subtle morphological details. The cercaria of P. proliferus has an I-shaped excretory bladder and does not have mucous gland cells. In contrast, that of Troglotrematidae gen. sp. has a Y-shaped excretory bladder and mucous gland cells. Besides, the redia of P. proliferus is elongate with a short intestine and contains 5-6 cercariae whereas that of Troglotrematidae gen. sp. is more round with a longer intestine and harbours 3-4 cercariae. Our results have shown the importance of the shape of the excretory bladder and the presence/absence of mucous gland cells of the cercaria as well as the shape and size of the redia, and its intestinal length as valuable taxonomic characters of intramolluscan trematode larvae. In addition, the finding of similar microcercous cercariae of different species in the same snail species suggests that careful attention to morphological details is required in the differentiation of Paragonimus cercariae and those of closely related species., Pham Ngoc Doanh, Hoang Van Hien and Bui Thi Dung., and Obsahuje bibliografii
Migratory birds have an important role in transporting ticks and associated tick-borne pathogens over long distances. In this study, 2,793 migratory birds were captured by nets in a ringing station, located in northern Italy, and checked for the presence of ticks. Two-hundred and fifty-one ticks were identified as nymphs and larvae of Ixodes ricinus (Linnaeus, 1758) and they were PCR-screened for the presence of bacteria belonging to Borrelia burgdorferi sensu lato, Rickettsia spp., Francisella tularensis and Coxiella burnetii. Four species of Borrelia (B. garinii, B. afzelii, B. valaisiana and B. lusitaniae) and three species of Rickettsia (R. monacensis, R. helvetica and Candidatus Rickettsia mendelii) were detected in 74 (30%) and 25 (10%) respectively out of 251 ticks examined. Co-infection with Borrelia spp. and Rickettsia spp. in the same tick sample was encountered in 7 (7%) out of the 99 infected ticks. We report for the first time the presence of Candidatus Rickettsia mendelii in I. ricinus collected on birds in Italy. This study, besides confirming the role of birds in dispersal of I. ricinus, highlights an important route by which tick-borne pathogens might spread across different countries and from natural environments towards urbanised areas., Massimo Pajoro, Dario Pistone, Ilaria Varotto Boccazzi, Valeria Mereghetti, Claudio Bandi, Massimo Fabbi, Francesco Scattorin, Davide Sassera, Matteo Montagna., and Obsahuje bibliografii
Giardiasis is a common gastrointestinal infection of humans and animals with a worldwide distribution. Eight genetic groups (known as assemblages A to H) are currently recognised within the species complex of Giardia duodenalis (Lambl, 1859), of which assemblages A and B are responsible for infection of humans and other mammalian hosts. Genotyping data on giardiasis are not available from Slovenia. In this work, we have characterised isolates of G. duodenalis from 85 human symptomatic cases collected during 2002-2013. Genomic DNAs were first tested by a real-time (rt) PCR assay and then by conventional PCR at three loci (beta-giardin, bg; triose phosphate isomerase, tpi; and glutamate dehydrogenase, gdh). We found that the threshold cycle (Ct) values in rt-PCR testing were higher for samples collected during 2002-2005 and that this was paralleled by a low amplification rate in conventional PCR (6 of 32, i.e. 19%). In contrast, lower Ct values and higher amplification rate (45 of 53; 85%) were observed for samples collected during 2006-2013, suggesting an adverse effect of prolonged freezing of stools. Assemblages A and B were found with an almost identical frequency in the 51 genotyped samples. In agreement with previous studies, sequences from assemblage B isolates were characterised by larger genetic variability and by the presence of heterogeneous positions, which made assignment to specific genotypes difficult. Less variability was observed in sequences from assemblage A isolates, which belonged to the human-specific subassemblage AII. These data showed that the genotypes of G. duodenalis that circulate in humans in Slovenia are similar to those previously identified in Europe., Barbara Šoba, Sabina Islamović, Miha Skvarč, Simone M. Cacciò., and Obsahuje bibliografii
Toxoplasmosis is a common parasitic disease caused by Toxoplasma gondii (Nicolle et Manceaux, 1908), an obligate parasite capable of infecting a range of cell types in almost all warm-blooded animals. Upon infecting an intermediate host, the parasites differentiate into tachyzoites which rapidly infect host tissues. Usually, the invading parasites are cleared by the immune system and administered drugs, but some tachyzoites differentiate into bradyzoites forming tissue cysts. These tissue cysts could serve as a source for re-infection and exacerbations. Currently, treatment for toxoplasmosis is limited and, moreover, there are no drugs for treating the cystic stage thus rendering toxoplasmosis a global burden. Recently, we demonstrated that inorganic nanoparticles showed promising activity against the tachyzoite stage T. gondii. In the present study, we evaluated nanoparticles for effect on bradyzoite formation in vitro. Data revealed that the nanoparticles limited bradyzoite burden in vitro. Further, the nanoparticles decreased the bradyzoite-specific BAG-1 promoter activity relative to the untreated control under a bradyzoite-inducing culture condition, even though this reduction in BAG-1 promoter activity waned with increasing concentrations of nanoparticles. In contrast, a parallel experiment under normal cell culture conditions showed that the nanoparticle treatment mildly increased the BAG-1 promoter activity relative to the untreated control. Taken together, the findings are evidence that nanoparticles not only possess anti-tachyzoite potential but they also have anti-bradyzoite potential in vitro., Oluyomi Stephen Adeyemi, Yuho Murata, Tatsuki Sugi, Yongmei Han, Kentaro Kato., and Obsahuje bibliografii