Spleen Fragments Research Articles

The effect of triterpene glycoside on survival and changes in the cytokine profile in the spleen of BALB/c mice under conditions of lethal influenza infection A/WSN/1/33(H1N1)

BACKGROUND: Currently, the search and development of compounds, including herbal ones, with anti-influenza activity are relevant.
 AIM: To study the effect of oral administration of the triterpene glycoside saponin tauroside Sx1 on survival and changes in the cytokine profile of the spleen of mice under conditions of lethal influenza infection.
 MATERIAL AND METHODS: 78 male BALB/c mice aged 4–6 weeks, weighing 16–18 g, were used. They were divided into groups: first — control group; the second was a group of animals infected with influenza virus A/WSN/1/33(H1N1); the third was a group of infected animals that received saponin tauroside Sx1, isolated from the Crimean ivy Hedera taurica (Hibberd) Carrière at a dose of 11.8 mg/kg per day against the background of a viral infection for 3 days. The survival and expression of interleukins-1β and -10 in the spleen of mice on the 4th and 14th days of the experiment were studied. Spleen fragments were stained with hematoxylin and eosin. Microscopic analysis was performed using a video microscopy system. Immunohistochemical study was performed according to a standard protocol. Intergroup differences were assessed using the Kruskal–Wallis test and the Mann–Whitney U test using MS Office (Excel 2010) and Statistica 10.0.
 RESULTS: Administration of saponin tauroside Sx1 significantly increased the average life expectancy of animals by 4.6 days compared to the group without correction; survival rate was 30.0% (p=0.0233). Against the background of influenza infection, an increase in the number of cells secreting interleukin-1β was detected in the spleen of mice. In the mantle zone of the second group, the level of cytokine expression exceeded the control values by 3.41 times (p=0.0001), and the values of the third group — by 3.38 times (p=0.0001). By the 14th day of the experiment in the mantle zone, expression in the group with saponin administration increased, exceeding the indicators of the group without correction by 34.78% (p=0.0482). By the 4th day of the experiment, in both experimental groups, the number of cells positive for interleukin-10 increased in the mantle zone and decreased compensatoryly in the marginal zone. By the 14th day, in the group without correction, a decrease in expression by 24.86% (p=0.0487) was recorded; after the administration of saponin, the number of immunopositive cells was practically no different from the control (p=0.0443).
 CONCLUSION: Therapeutic administration of saponin tauroside Sx1 stabilizes the cytokine profile of the spleen of mice and promotes their better survival in conditions of lethal influenza infection.

Molecular Survey of Haemosporidian Parasites in Procellariiformes Sampled in Southern Brazil, 2013-22.

The order Procellariiformes includes several species of seabirds that perform long-distance migrations crossing all the oceans. These movements may contribute to the dispersal and exchange of hemoparasites, such as haemosporidians. There is a lack of studies regarding the order Haemosporida in Procellariiformes, and, to date, only the genus Plasmodium has been reported. This survey investigated the occurrence of the three genera of haemosporidians, Plasmodium, Haemoproteus, and Leucocytozoon, in samples collected between 2013 and 2022 from 95 individuals of 14 species of Procellariiformes from southern Brazil, including live animals in rehabilitation centers, individuals caught as incidental bycatch, and carcasses found along the coast. A total of 171 samples of blood and fragments of liver and spleen were analyzed, with extracted DNA being subjected to a nested PCR followed by phylogeny analysis. All animals were negative for Plasmodium spp. and Leucocytozoon spp., but one Black-browed Albatross (Thalassarche melanophris) and one Manx Shearwater (Puffinus puffinus) specimen were positive for Haemoproteus spp. The sequences obtained from positive seabirds did not show 100% similarity with other known lineages available in the MalAvi database and thus were probably novel lineages. However, one sequence clustered together with Haemoproteus noctuae, a parasite from Strigiformes, while the other was grouped with Haemoproteus columbae, which is classically related to Columbiformes. These results suggest that both positive animals may have become infected when beached or in rehabilitation centers by a spillover of vectors from local birds. This highlights the importance of surveillance of the health of Procellariiformes regarding the possibility of dissemination of new pathogens in different bird populations.

The relationships among Leishmania infantum and phyllostomid bats assessed by histopathological and molecular assays

Bats have been reported as reservoir host of Leishmania spp. worldwide, mostly by molecular detection. However, it is still unclear whether bats act as reservoirs of Leishmania infantum to sandflies vectors. In this sense, the investigation of amastigotes forms in the target organs, and the characterization of their associated inflammation, may help to clarify the epidemiological importance of bats in endemic areas for leishmaniasis. The aim of this work was to investigate the host-parasite relationships under microscopic evaluation and predict the epidemiological role of two phyllostomid bats species naturally infected by L. infantum in an endemic area for human leishmaniasis. Fragments of skin, liver and spleen of L. infantum positive and negative bats (Artibeus planirostris and Carollia perspicillata) by qPCR, were studied by histological and immunohistochemical techniques. Both groups, positive and negative, did not show differences in the histopathological study, presenting only discrete tissue changes. Liver and skin showed mild inflammatory reactions. Findings on spleen consisted of reactivity of the lymphoid follicles, expressive presence of apoptotic cells and macrophages containing abundant phagocytic cells debris. We did not find amastigote forms in tissues by histological and IHC techniques in positive qPCR bats. Our results allow us to hypothesize that phyllostomid bats seem to have an important role in reducing the risk of transmission, possibly acting as dead-end host.

A novel variant of Babesia sp. (Piroplasmida) as a hemoparasite in procellariiform seabirds.

Procellariiformes includes pelagic seabirds that only use land for breeding; and also,these sites mostly occur in insular habitats. These peculiar habits make the investigation of hemoparasites a challenging issue. Thus, the data on the blood parasites of Procellariiformes are still scarce. In the order Piroplasmida, 16 species of Babesia have been described in terrestrial birds and seabirds. However, there is no register for Babesia spp. in procellariiform seabirds. Hence, the objective of this survey was to investigate the occurrence of Babesia spp. in these seabirds. A total of 220 tissue samples from 18 different seabird species were analyzed; the samples comprised blood and fragments of liver and spleen. The samples were obtained from live rescued animals and carcasses found along the southern coast of Brazil. Polymerase chain reaction (PCR) was conducted, followed by phylogenetic analysis. Only one blood sample yielded a positive result, from an adult female Thalassarche chlororhynchos (Atlantic yellow-nosed albatross). The sequence obtained showed the highest identity with sequences of Babesia spp. of birds from the South Pacific, and the isolate was named Babesia sp. strain Albatross. In the phylogenetic analysis, the sequence was grouped within the Babesia sensu stricto group, and further still into a subgroup including Babesia spp. of the Kiwiensis clade (parasites from birds). The phylogenetic analysis also showed that Babesia sp. strain Albatross clustered apart from the Peircei group, a clade that includes Babesia spp. from seabirds. As far as it is known, this is the first report of Babesia sp. in procellariiform seabirds. Babesia sp. strain Albatross may constitute a novel variant of tick-borne piroplasmids associated with the Procellariiformes order.

Place of the cardiosplenic axis in the development of fatal myocardial infarction

Aim. To compare data on the features of spleen macrophage composition in pa­tients with fatal myocardial infarction (MI) and in patients from the control group without cardiovascular disease (CVD).Material and methods. The study included patients with fatal MI (n=30) and control group (n=5) — persons without CVD who died from injuries not compatible with life. Macrophage infiltration of spleen and myocardium fragments taken during autopsy was assessed by immunohistochemistry using macrophage markers CD68, CD163, CD206, stabilin-1.Results. There were following number of cells studied by us in the red pulp (RP) in patients with MI: CD163+, 906 (661; 1101), CD68+, 898 (807; 1049), stabilin-1+, 811 (531; 966), CD206+, 11 (9; 19); control group: CD163+, 400 (315; 513), CD68+, 40 (37; 45), stabilin-1+, 186 (107; 206), CD206+, 80 (70; 84). The content of all cells in the RP in patients with MI was high and prevailed over their number in the control group, while only the CD206+ concentration was inferior in number; in the control group, CD163+ cells predominated (p<0,05). There were following number of cells in the white pulp (WP): CD68+, 312 (260; 348), stabilin-1+, 59 (40; 123), CD163+, 29 (17; 56), CD206+, 2 (1; 5) in the group with MI; CD68+, 3 (1; 4), stabilin-1+, 3 (2; 3), CD163+, 23 (1; 48), CD206+, 1 (1; 2) in the control group. In persons with MI, CD68+ cells dominated in WP, while in the control group — CD163+ (p<0,05). The minimum and comparable in WP in both groups was the number of CD206+ cells (p<0,05), which correlated in the control group with the level of stabilin-1+ and CD206+ cells (r=-0,9, p=0,003) and in patients with MI — with the level of CD206+ cells in the myocardium (r=0,6, p=0,004).Conclusion. The dominance of CD163+ cells in all functional spleen areas in the control group and CD68+ cells in patients with MI was revealed. The only cell type, the content of which in the control group prevailed over that in MI in RP and correlated in WP with its myocardial concentration, was CD206+.

Decrease of reproductive performance of Nile tilapia (Oreochromis niloticus) females with dysmorphia in urogenital papilla

The seed production of Nile tilapia (Oreochromis niloticus) can be considerably reduced when inefficient breeders are present in the broodstock. Females with dysmorphia in urogenital papilla were identified and characterized in the present study and their reproductive performance were compared to normal tilapias in three different temperatures (28 °C, 26 °C and 24 °C). We also evaluated the effects of dysmorphia in urogenital papilla on biological indexes and its possible association with pathological bacteria. From a broodstock of Nile tilapia (600 females and 150 males), 96 normal males, 96 females with normal urogenital papilla and 96 females with abnormal urogenital papilla were selected. All tilapias were individually identified by tags and reared in a biofloc system during the stocking. We performed three reproductive cycles in clear water, each one of three weeks, totalizing 9 weeks of reproduction. Different temperatures were used in each cycle, being the first at 28 °C, the second at 26 °C and the third at 24 °C. In each week, we used eight 3.6 m3 tanks with 8 females and 6 males, half of the tanks (4 tanks) had normal females and the other half with abnormal females. For each female group, there was a resting period of two weeks between each reproductive cycle. During the assays, we monitored the water quality. After reproductive assays, the animals were photographed, euthanized and the body weights, viscera, gonads, and liver were obtained for biological indexes calculation. We performed bacteriological examination, where fragments of brain, kidney, spleen, and gonads from 8 abnormal females were inoculated onto blood and Macconkey agar. The macroscopic alteration in the urogenital papilla was also associated with lesions in ovaries. The odds of females with normal urogenital papilla effectively reproduce was approximately 3, 5 and 12 times than females with abnormal papilla, in the first, second, and third cycles, respectively. The larvae number per tank produced by normal females was approximately 3, 5 and 5 times than females with abnormal urogenital papilla in the first, second and third reproductive cycle, respectively. The gonadosomatic, viscerosomatic, hepatosomatic and viscerosomatic fat indexes were not different between the normal and abnormal females. The bacteriological examination was negative for all samples. In conclusion, the morphology of urogenital papilla is a good predictor of reproductive performance of Nile tilapia and should be used for breeder selection.

Oral and Intragastric: New Routes of Infection by Leishmania braziliensis and Leishmania infantum?

Although Leishmania transmission in nature is associated with the bite of an infected sandfly vector, other possible transmission routes are speculated to occur, such as the oral route. We evaluated the possibility of infection by this route in golden hamsters (Mesocricetus auratus) using Leishmania braziliensis (Lb) and Leishmania infantum (Li). Hamsters were exposed to experimental oral or intragastrical infection with axenic promastigotes, besides oral ingestion of a suspension of cultivated macrophages infected with amastigotes, lesion-fed Lutzomyia longipalpis, skin lesion or infective spleen fragment. The parasite’s isolation, besides a positive PCR and IFAT, confirmed the intragastric infection by promastigote parasites. The oral ingestion of macrophages infected with L. braziliensis amastigotes was also infective. These results confirmed that Leishmania parasites could infect mammals by the intragastric route through the ingestion of promastigote forms (what can happen after a sandfly ingestion) and by the oral ingestion of infected macrophages (what can happen in nature in a predator–prey interaction). The better understanding of these alternative routes is essential to understand their transmission dynamics in nature. As far as we know, this is the first time that oral and intragastric Leishmania transmission has been experimentally demonstrated, constituting new infection routes, at least for L. infantum and L. braziliensis.

Pathomorphological changes in German boxer dog infected with Babesia canis parasites. Clinical case

The article covers the results of a comprehensive pathomorphological study of Babesia canis parasitic infestation in a dog of the German boxer breed. In April 2020, a male German boxer with pronounced clinical signs of anorexia, remitting fever, hematuria, and manifestations of general jaundice was admitted to the Dr. Markevych clinic (Lviv). The anamnesis evidenced that after daily walks in the park of Lychakiv district (Lviv) the pet’s owner had been detecting 3–5 Ixodes ticks on the dog’s body for several days in a row. Cytological examination of blood smears stained by the Romanovsky–Giemsa method revealed a massive lesion of erythrocytes by the Babesia canis parasite. The applied treatment strategy, namely the introduction of the drug with the active substance imidocarb dipropionate, was not successful. The dog died in the clinic. An autopsy was performed in agreement with the pet owner. Macroscopic examination revealed foamy fluid in the trachea, pulmonary edema and lobar pneumonia, massive diffuse hemorrhages on the epicardium and costal pleura, splenomegaly, serous lymphadenitis, acute venous stasis, hepatic and renal dystrophy, and pancreonecrosis. General anemia and transudate accumulation in serous cavities were established. Tissue fragments of lungs, kidneys, liver, spleen, and pancreas were selected for a histopathological examination and fixed in 10 % neutral aqueous formalin solution, followed by dehydration in alcohols, filling into paraffin blocks and subsequent production of histopreparations. Staining was performed with eosin and Ehrlich’s hematoxylin according to the conventional methods. Microscopically, the lungs showed the alveoli swelling, thickening of the alveoli walls with blood overflow, bronchioles’ inflammatory infiltration with the accumulation of desquamated epithelium and exudate in the lumens of large bronchi. Extracapillary glomerulonephritis and hyaline-drop renal tubular dystrophy were observed in the kidneys. Vascular endothelium edema, granular hepatocyte dystrophy, sharp dilation of central vein and intraparticle and interparticle capillaries were found in the liver. Significant hyperplasia was observed in the red pulp of the spleen. Reticuloendothelial proliferation, erythrocyte proliferation with a diffuse accumulation of hemosiderophages due to increased erythrocyte disintegration, sinus dilatation, and atrophy of white pulp lymph nodes were also revealed.

Successful experience with axenic isolation of Leishmania infantum in culture medium enriched with equine blood

The aim of the study was to demonstrate a successful experience in the axenic isolation of Leishmania infantum (L. infantum) promastigotes in culture using base agar media enriched with defibrinated equine blood (SDE). The study used lymph node aspirate, spleen, liver and lymph node fragments from dogs infected with the disease. The culture media used for the isolation of the parasite were biphasic (solid and liquid) and monophasic (liquid). For a biphasic phase, Blood Agar Base (BAB) and Neal Novy Nicolle (NNN) medium were used, both enriched with SDE, which after solidification was added to Brain Heart Infusion (BHI) broth. For the monophasic phase, Medium 199 (M199) supplemented with 10% fetal bovine serum (SFB) was used. The promastigotes were seeded in duplicate, kept in an oven by biochemical oxygen demand at 25º C for 15 days. Microscopic readings were taken daily to monitor the primary growth phase of the parasite. After primary isolation, they were serialized and diluted with a final concentration of 1x106 parasites/mL, for evaluation of the growth curve. The continuous study showed that in tubes containing SDE enriched NNN and BAB biphasic media, primary parasite growth was 72 hours, whereas in tubes supplemented with SFB it was 96 hours. Regarding the growth curve, it was observed that during an exponential phase, as SDE enriched spleen, liver and lymph node fragments obtained greater promastigotes, when used with SFB supplemented ones, being 189 x 106 e 128 x 106 parasites/mL, respectively. There was a significant difference (P < 0.05) in the percentage of the number of promastigotes in a medium enriched with SDE, when compared to the medium with SFB. The primary tubes remained viable throughout the study period, even after replenishing used to maintain the parasite. The traditional technique of isolation of the parasite in culture medium most commonly used is in base agar enriched with rabbit blood; however, operational difficulties in the acquisition of this enricher have driven the search for other sources of protein supplementation for L. infantum cultivation. The study reveals that the use of SDE as an alternative enrichment medium for the primary isolation of L. infantum was feasible to be used in laboratory routine.

Porcine lymphotropic herpesvirus (Gammaherpesvirinae) DNA in free-living wild boars (Sus scrofa Linnaeus, 1758) in Brazil.

BackgroundSuid gammaherpesvirus 3, 4, and 5 (porcine lymphotropic herpesvirus – PLHV-1, -2, and -3) are viruses that infect domestic and feral pigs.ObjectivesThis study examined the presence of PLHV DNA in biological samples from free-living wild boars circulating in a Brazilian geographical region with a high density of commercial domestic pigs.MethodsLung samples of 50 free-living wild boars were collected by exotic wildlife controller agents between 2017 and 2019 in the state of Paraná, southern Brazil. Lung and spleen fragments were obtained from six fetuses collected by hysterectomy post mortem from a pregnant sow. A polymerase chain reaction (PCR) assay using consensus primers (pan-herpesviruses) was performed to detect PLHV DNA. The samples showing positive results for PLHV DNA were submitted to single-round PCR assays with the specific primers for identifying PLHV-1 (213-S/215-As), PLHV-2 (208-S/212-As), and PLHV-3 (886s/886As). The specificity of the species-specific PCR products was assessed by nucleotide sequencing of the amplicons.ResultsForty-eight (96%) of the 50 lung samples analyzed were positive for PLHV by PCR using pan-herpesvirus primers. In 33 (68.75%) of the positive samples, at least two PLHV species were identified simultaneously. The DNA of PLHV-1, -2, and -3 was found in free-living wild boars of all ages, but not in the fetuses, even though they were from a sow that tested positive for all three viruses.ConclusionThese viruses are endemic to the population of feral pigs in the Brazilian region evaluated, as well as in domesticated pigs.

Can histology and haematology explain inapparent Streptococcus agalactiae infections and asymptomatic mortalities on Nile tilapia farms?

The aim of this study was to characterise possible histopathological and haemato-immunological changes after subclinical infection by S. agalactiae S13 serotype Ib. One hundred juveniles of Nile tilapia with average weight of 45 g were distributed in ten 90 L experimental units. After the acclimation period 25 fish were euthanised, and fragments of liver, spleen and posterior mid-intestine tissue were sampled to verify the integrity of the organs and blood samples taken to check the haematological profile. Fifty animals were used to verify the optimal dosage for the challenge. The remaining 25 fish were infected with S. agalactiae S13. After 96 h, tissue fragments from the liver, spleen and posterior mid-intestine and blood samples were collected. The analyses revealed that, 96 h after contagion, S. agalactiae S13 serotype Ib caused subclinical lesions in the liver and spleen that are not commonly described as pathognomonic, in addition to haematological alterations. These results allow a better understanding of sudden recurrent mortalities in Brazilian tilapia farms, since the serotype Ib of S. agalactiae causes inapparent infections and can remain lodged in internal organs and cause irreversible lesions and haemato-immunological alterations, therefore compromising physiological functions vital for the health of fish without revealing external clinical signs in the animals.

Howler monkeys are the reservoir of malarial parasites causing zoonotic infections in the Atlantic forest of Rio de Janeiro.

BackgroundAlthough malaria cases have substantially decreased in Southeast Brazil, a significant increase in the number of Plasmodium vivax-like autochthonous human cases has been reported in remote areas of the Atlantic Forest in the past few decades in Rio de Janeiro (RJ) state, including an outbreak during 2015–2016. The singular clinical and epidemiological aspects in several human cases, and collectively with molecular and genetic data, revealed that they were due to the non-human primate (NHP) parasite Plasmodium simium; however, the understanding of the autochthonous malarial epidemiology in Southeast Brazil can only be acquired by assessing the circulation of NHP Plasmodium in the foci and determining its hosts.MethodologyA large sampling effort was carried out in the Atlantic forest of RJ and its bordering states (Minas Gerais, São Paulo, Espírito Santo) for collecting and examining free-living NHPs. Blood and/or viscera were analyzed for Plasmodium infections via molecular and microscopic techniques.Principal findingsIn total, 146 NHPs of six species, from 30 counties in four states, were tested, of which majority were collected from RJ. Howler monkeys (Alouatta clamitans) were the only species found infected. In RJ, 26% of these monkeys tested positive, of which 17% were found to be infected with P. simium. Importantly, specific single nucleotide polymorphisms–the only available genetic markers that differentiate P. simium from P. vivax–were detected in all P. simium infected A. clamitans despite their geographical origin of malarial foci. Interestingly, 71% of P. simium infected NHPs were from the coastal slope of a mountain chain (Serra do Mar), where majority of the human cases were found. Plasmodium brasilianum/malariae was initially detected in 14% and 25% free-living howler monkeys in RJ and in the Espírito Santo (ES) state, respectively. Moreover, the malarial pigment was detected in the spleen fragments of 50% of a subsample comprising dead howler monkeys in both RJ and ES. All NHPs were negative for Plasmodium falciparum.Conclusions/SignificanceOur data indicate that howler monkeys act as the main reservoir for the Atlantic forest human malarial parasites in RJ and other sites in Southeast Brazil and reinforce its zoonotic characteristics.

Pathological and molecular characterization of avian malaria in captive Magellanic penguins (Spheniscus magellanicus) in South America.

Avian malaria is a mosquito-borne disease that affects multiple avian species and is caused by protozoans of the genus Plasmodium. An avian malaria infection caused by Plasmodium sp. in Magellanic penguins (Spheniscus magellanicus) with high mortality is described in a zoo in Southern Brazil. Clinically, three birds presented signs of inappetence, anorexia, pale mucosa, dyspnea, and opisthotonus, with death in a clinical course of 5-8h. At the necropsy, all birds exhibited pale mucosa, marked splenomegaly and hepatomegaly, in addition to moderate leptomeningeal blood vessels ingurgitation in the brain. Microscopically, multiple exoerythrocytic meronts were observed in the cytoplasm of endothelial cells in the spleen, liver, heart, lungs, brain, kidneys, and pancreas. The spleen had a multifocal perivascular inflammatory infiltrate of lymphocytes, plasma cells, and macrophages, which also exhibited hemosiderosis and erythrophagocytosis. The liver had a multifocal periportal inflammatory infiltrate of lymphocytes, macrophages, and plasma cells, in addition to marked hemosiderosis in the hepatic sinusoids. Fragments of spleen, liver, brain, skeletal muscle, and lung were tested by the polymerase chain reaction technique for the detection of a fragment of the cytochrome B gene from haemosporidians, which resulted positive for Plasmodium spp. After sequencing, the samples were phylogenetically associated to Plasmodium sp. detected in Turdus albicollis (KU562808) in Brazil and matched to the lineage TURALB01 previously detected in T. albicollis. Avian malaria infections caused by Plasmodium sp. of lineage TURALB01 may occur in S. magellanicus with high mortality, and, thus, it is essential to detect and characterize the agent involved to obtain the differential diagnosis of the condition.

Linfossarcoma de células B multicêntrico em uma ovelha

Background : : : Lymphosarcoma is a malignant tumor from tumoral cells similar to lymphocytes and its spontaneous development in small ruminants is unusual in Brazil. In cattle, the lymphosarcomas are often associated with infection by bovine leukemia virus (BLV), although sheep are considered as a very susceptible specie to BLV. Spontaneously lymphosarcoma is rare and in most cases it is observed in apparently healthy animals in slaughterhouses. There is no report of this tumor in sheep in southern Brazil. We describe a case of spontaneous multicentric B-cells lymphosarcoma in an ewe. Case : In June 2007, a 4-years-old mixed breed ewe was necropsied after clinical signs as anorexia, weight loss and death in few weeks. This ewe was purchased in September 2006 with another 44 sheep, most females of the same age. Dairy cattle were also raised together with sheep at the same farm. Fragments of liver, lung, spleen, kidneys, brain and parotid lymph node were sent to the Veterinary Pathology Laboratory - Universidade Federal de Santa Maria, Brazil, for histopathological evaluation. Multiply white to yellow nodules, with 0.5 to 2 cm of diameter, were observed in the liver, kidneys, and the parotid lymph node. The nodules were soft and some coalesced and infiltrating the hepatic parenchyma. The kidneys nodules were similar to those of the liver but prominent in the capsule. They were observed infiltrating more intensely the cortical region. The parotid lymph node was 6 x 4 x 3.5 cm size, whitish, multilobulated and the cut surface was totally obliterated by the tumor mass. Histologically, the neoplasm showed intense proliferation of neoplastic lymphoid cells arranged in sheets and a poor fibrovascular stroma, with round small and hyperchromatic nuclei, and scarce eosinophilic cytoplasm compressing the adjacent parenchyma. Immunohistochemistrily, neoplastic cells were strongly positive for anti-CD79a antibody and negative for anti-CD3 antibody, indicating neoplastic cells derived from B lymphocytes. Discussion : The diagnostic of multicentric B-cell lymphosarcoma was made based on gross, histological, and immunohistochemical findings. Spontaneous development of this tumor is uncommon in sheep in Brazil. The multicentric presentation seen in this case is the most common form of lymphosarcoma in sheep, although the thymic and cutaneous forms also occur. Sheep affected by multicentric lymphosarcomas may have symmetrical lymphadenopathy, not observed in this case, and involvement of various organs including liver, kidney, spleen, intestine, skeletal muscle and heart. However, under experimental conditions, these tumors are easily induced after inoculation of bovine retrovirus (BLV) in sheep, by its high sensitivity. Possibly, the spontaneous transmission of BLV from cattle developing the disease in sheep may occur in Brazil as well as in other countries. Epidemiological factors of the disease are not established yet. Despite this, some correlation must exist for the low occurrence of this disease in sheep in properties of southern Brazil, where cattle and sheep are commonly raised together, and the frequency of lymphosarcoma in sheep is low. In this case, the association of BLV with development of the neoplasm could not be confirmed. This is the first report of multicentric B-cell lymphosarcoma in sheep diagnosed in southern Brazil.

Salmonella Enteritidis detection and immunological cellular response to experimental inoculation in day-old turkeys

The purpose of this research is to clarify aspects of the pathogenesis of Salmonella Enteritidis in experimentally inoculated day-old turkeys. Three treatments were conducted among a total of 120 turkeys; one control group and two treatment groups in which 6 x 102 CFU mL-1 and 7 x 105 CFU mL-1, respectively, of Salmonella Enteritidis was inoculated in the crops. Two birds from each treatment were sacrificed and necropsied at 1, 3, 4, 12, 18, and 24 hours, and 3, 4, 38, and 49 days post-inoculation. We re-isolated Salmonella, measured lymphocytes, and conducted immunohistochemical tests. Six hours post-inoculation, Salmonella was found in the investigated organs (yolk sac, cecum, fragments of spleen, and bursa of Fabricius) with conventional bacteriology and immunohistochemistry, and was continuously detected in almost all analyzed organs until turkeys were four-days old. Further, Salmonella was detected after 38 days in cecum, when the concentration 7 x 105 CFU mL-1 was given. At both inoculation concentrations, the number of lymphocytes was similar; larger quantities were found in the first hour post-inoculation, followed by a gradual reduction, reaching the lowest levels at 24 hours after inoculation. Afterwards, lymphocytes increased discreetly, remaining at the same level until 49 days after inoculation. In conclusion, inoculation concentration influences mitigation, dissemination, elimination, and persistence of this pathogen in turkeys. Lower concentrations promote less invasion as well as lower cell stain and lower lymphocyte count.

Investigation of farmed Nile tilapia health through histopathology

Confinement is a stressful practice for fish, which can culminate in tissue damage and production losses. Histopathological examination is a technique capable of forthcoming the normal and pathological conditions in fish. It reflects the animal's health and welfare, being able to apply measures to mitigate the stress and diseases in fish farming. This study evaluated the health status of cultured Nile tilapia using histopathological examination as a tool. Fragments of gills, liver, heart and spleen of 60 tilapias from fish farms in southern Brazil were collected and fixed. All crops were free of sanitary problems and fish were clinically healthy. This study showed a positive correlation between Trichodina species, protozoans and hyperplasic epithelium in the secondary lamellae and lamellar fusion, as well as the role of parasites in the inflammatory response in tilapia gills. Nonetheless, alterations such as hyperplasia of interlamellar epithelium were persistent even in non-parasitized animals, suggesting being an adaptation to the confinement environment. The presence of melanomacrophage centers in the liver and spleen were characteristic of the chronic stress that the cultured fish are exposed to. Histological findings such as epitheliocystis in the gills and bacterial colonies in the liver, spleen and heart, showed that even with absence of mortality, bacteremia were present in healthy farmed fish, as well as the parasitic diseases culminating in mixed infections. This study presented unprecedented results on tissue changes in farmed tilapia, serving as an assistance for what can be considered normal in the histopathological examination in farmed fish. Fish herein used did not present any production loss and did not have the relative condition factor (Kn) influenced by the changes, indicating a good health status. Thus, this study reports the first occurrence of epitheliocystis in tilapia gills grown in southern Brazil.

Histopathological changes induced by Hysterothylacium deardorffoverstreetorum larvae (Nematoda: Raphidascarididae) in Priacanthus arenatus Cuvier, 1829 (Actinopterygii).

Priacanthus arenatus is a fish that occurs in the waters of the western Atlantic Ocean and has few records of parasitism. This study aimed to report histological changes caused by the larvae of Hysterothylacium deardorffoverstreetorum. Between July and December, 2013, 30 samples of P. arenatus were obtained from fish markets in the cities of Niterói and Rio de Janeiro, state of Rio de Janeiro, Brazil. Fragments of spleen, liver, stomach wall and mesentery tissues containing nodules and free parasites were extracted to histopathological study. Through histological analysis it was verified that these nodules consisted of connective tissue capsules, in which the parasites were located, with granulomatous inflammation mainly comprised of macrophages and lymphocytes. These nodules also consisted of a central portion of acellular amorphous material, formed by concentric layers, which was slightly basophilic and contained tunnels and, sometimes, parasite debris. The presence of tunnels in acellular amorphous material suggests that the larvae are initially located at the center of the nodules and then they migrate to the surface.

Endosomal RNA-sensing toll-like receptor stimulated T cells play a unique role in autoimmune manifestations in murine model of DNA accrual.

Abstract DNaseII is a lysosomal DNase that plays a critical role in immune homeostasis. DNaseII deficiency in mice causes embryonic lethality, due to severe anemia associated with excessive production of type I interferon (IFN), and can be rescued by IFN receptor knockout (IFNaR). The DNaseII/IFNaR double knockout (DKO) mice develop a late-onset inflammatory arthritis, dependent on the cytosolic DNA sensor STING (Stimulator of Interferon Genes). They also develop early-onset clinical manifestations of systemic autoimmunity including disrupted hematopoiesis and B cell lymphopoiesis, splenomegaly (due to increased accumulation of Ter119+ cells), and the production of anti-nuclear antibodies (ANA), through a mechanism that is STING-independent, Unc93B1-dependent and likely to result from endosomal RNA-sensing TLRs. Bone marrow (BM) chimera studies have shown that the DNaseII deficiency is essential in both radioresistant host cells and hematopoietic donor cells for all disease manifestations. Development of arthritis requires the presence of STING in both host and donor. The TLR-dependent defects require TLR expression in only the hematopoietic compartment but still need DNaseII−/− recipients. Remarkably transplantation of DKO spleen fragments or injection of DKO spleen cells alone into DNaseII-sufficient Rag−/− mice leads to splenomegaly and disrupted hematopoiesis and lymphopoiesis. Moreover DKO T cells are sufficient to transfer these TLR-associated defects to the Rag−/− mice. As activated T cells are known to be radioresistant, T cells activated in a DKO environment may account for the radioresistant host component required to precipitate the TLR-dependent disease manifestations.

Pathologic and microbiologic aspects of pet psittacine infected by Escherichia coli and Salmonella Typhimurium

ABSTRACT: The role of Escherichia coli in healthy microbiota of psittacine is controversial, and the presence of Salmonella sp. indicates possible disease. Therefore, this study aimed to identify the presence of E. coli and Salmonella spp. in a psittacine pet that died in Fortaleza, Brazil, correlating pathogenicity aspects of the isolates through the evaluation of lesions and antimicrobial susceptibility. Psittacine pets sent to the Laboratory of Ornithological Studies, State University of Ceará, that died in 2014 and 2015 were necropsied. Fragments of liver, kidneys, intestine, lung, heart, spleen and brain were collected for microbiological and histopathological analyses. Scores were attributed to lesions and isolated strains submitted to antimicrobial susceptibility test. From the seventy necropsied birds, nineteen were positive for E. coli and one for Salmonella Typhimurium. Congestive lesions and lymphoplasmocitic inflammatory infiltrate were observed varying from light to moderate and were the main findings. In the analyzed strains, multidrug resistance against different groups of antibiotics was observed. In conclusion, according to the results, E. coli strains and the Salmonella Typhimurium isolate produced significant lesions in the psittacine pets, and multidrug resistance may hinder treatments with antibiotics used in avian pet medicine.

Homeopathic medicines cause Th1 predominance and induce spleen and megakaryocytes changes in BALB/c mice infected with Leishmania infantum

The prevalence of Th1/Th2 response, spleen changes and megakaryocytes were investigated in BALB/c mice (n=138) infected with Leishmania infantum, and treated with Leishmania infantum 30× (10−30) biotherapy – BioLi30×. We performed controlled experiments using 8-to-12-week-old mice, infected with 5×107L. infantum promastigotes, divided into eight groups: G1 (healthy), G2 (infected with L. infantum), G3 (BioLi30× pre-treated), G4 (BioLi30× pre/post-treated), G5 (BioLi30× post-treated), G6 (Water 30× post-treated), G7 (Antimonium crudum 30× post-treated) and G8 (Glucantime® post-treated). G3–G7 groups were orally treated with their respective drugs diluted in filtered water (1:10), and G8 received Glucantime® (0.6mg/100µl of PBS), intraperitoneally. Spleen fragments were submitted to double blind histopathological evaluation and the number of megakaryocytes was counted. Besides, animals’ serum was measured after 49days of infection, and cytokines (IFN-γ, IL-4, IL-10, IL-12), as well as the Th1/Th2 correlation (IFN-γ/IL-4 and IFN-γ/IL-10), were analyzed. Spleen histological parameters were classified as: healthy appearance (G1); discreet (G3–G7), moderate (G2) and moderate to severe (G8) white pulp hyperplasia; proliferation of megakaryocytes (G2–G8), and intense disruption (G2–G8). All groups, except for G7, showed higher percentages of megakaryocytes per field ranging from 87% to 15%, when compared to healthy animals (G1). Th1 predominance in IFN-γ/IL-4 ratio (comparing to G2) was detected in G4, G5, G6 and G7. Finally, pre/post (BioLi30x) and post-treatment (Antimonium crudum 30x) presented reduction of megakaryocytes/spleen changes due to immunomodulation animal process, controlling the infection process, probably by the Th1 cytokine predominance.