Cell and Tissue Tropism of Brucella spp.

Brucella spp. are facultatively intracellular bacteria that can infect, survive, and multiply in various host cell types in vivo and/or in vitro. The genus Brucella has markedly expanded in recent years with the identification of novel species and hosts, which has revealed additional information about the cell and tissue tropism of these pathogens. Classically, Brucella spp. are considered to have tropism for organs that contain large populations of phagocytes such as lymph nodes, spleen, and liver, as well as for organs of the genital system, including the uterus, epididymis, testis, and placenta. However, experimental infections of several different cultured cell types indicate that Brucella may actually have a broader cell tropism than previously thought. Indeed, recent studies indicate that certain Brucella species in particular hosts may display a pantropic distribution in vivo. This review discusses the available knowledge on cell and tissue tropism of Brucella spp. in natural infections of various host species, as well as in experimental animal models and cultured cells.

Pathogenesis of Brucella ovis in pregnant mice and protection induced by the candidate vaccine strain B. Ovis ΔabcBA.

Ovine brucellosis caused by Brucella ovis is a major cause of reproductive failure in sheep. This study aimed to evaluate transplacental infection and pathogenicity of B.ovis wild type strain ATCC 25,840 (WT B.ovis) and the candidate vaccine strain B.ovis ΔabcBA in pregnant mice. A total of 40 BALB/c mice were equally divided into 4 groups: (i) non immunized and uninfected control mice (3/10 mice became pregnant); (ii) non immunized and challenged with WT B.ovis (5/10 pregnant); (iii) inoculated only with B.ovis ΔabcBA (6/10 pregnant); (iv) immunized with B.ovis ΔabcBA and challenged with WT B.ovis (5/10 pregnant). Female mice bred, and five days after visualization of the vaginal plug, they were inoculated intraperitoneally (ip) with 100 µL of sterile PBS, 100 µL of 1 × 106 CFU of B.ovis ΔabcBA, or 100 µL of 1 × 106 CFU of B.ovis WT, according to each group. At the 17th day of gestation, samples of spleen, liver, uterus, placenta, fetus and mammary gland were obtained for bacteriology, histopathology and immunohistochemistry. Non immunized mice challenged with B.ovis WT developed necrotizing placentitis as well as microgranulomas in the liver and spleen. These findings support the notion that B.ovis infection in pregnant mice induces lesions that are similar to those caused by B.abortus in the same animal model. B.ovis ΔabcBA was not recovered from any of the sampled organs, and it did not cause any gross or microscopic lesions, indicating that it is a safe and attenuated strain in this experimental model. In addition, B.ovis ΔabcBA was induced protective immunity as demonstrated by decreased numbers of B.ovis WT in the liver, uterus and fetuses of immunized mice after the challenge with B.ovis WT.

Natural cururu toad (Rhinella sp.) poisoning in a free-ranging lesser grison (Galictis cuja): Outcomes in a new susceptible predator with a novel peptide description.

Cururu toad (Rhinella marina group) is widely distributed in Brazil. Lesser grison (Galitic cuja) is a South American mustelid. This is the first report of natural poisoning in a free-ranging lesser grison by Rhinella toad parotoid gland secretion (PGS). Five minutes after biting a toad, the lesser grison developed convulsion, dying within 1.5 h. Mass spectrometry analysis of a milky-whitish secretion found in the lesser grison oral cavity allowed identification of a bufotoxin and a new bufonid peptide.

Necrotizing placentitis in a cow caused by Bacillus cereus / Placentite necrotizante em uma vaca por Bacillus cereus

ABSTRACT: This report described a case of necrotizing placentitis caused by Bacillus cereus in a cow associated with abortion and maternal lethality. The etiological diagnosis of placentitis by B. cereus was based on histopathology of placenta, cytology and bacterial isolation from intrauterine aminiotic fluid in retained placenta and further characterization of the pathogen by the MALDI-TOF. Although, B. cereus abortions are sporadic, the bacterium has the ability to release necrotizing toxins that can lead to placentitis, fetal death and abortion.

RESUMO: Este relato descreve a placentite necrotizante causada por Bacillus cereus em uma vaca associada a aborto e mortalidade materna. O diagnóstico etiológico de placentite por B. cereus foi baseado na histopatologia da placenta, citologia e isolamento bacteriano partir do líquido aminiótico em placenta retida e identificação do patógeno pela técnica de MALDI-TOF. Embora abortos por B. cereus sejam esporádicos, a bactéria tem a capacidade de liberar toxinas necrotizantes que podem levar a placentite e aborto.

Histopathologic Patterns and Susceptibility of Neotropical Primates Naturally Infected With Yellow Fever Virus.

Yellow fever is an important zoonotic viral disease that can be fatal for both human and nonhuman primates. We evaluated histopathologic changes in free-ranging neotropical primates naturally infected with yellow fever virus (YFV) compared with uninfected cohorts. The most frequent lesions in primates infected with YFV were hepatic changes characterized by midzonal necrosis with lipidosis and mild inflammation including lymphocytes, macrophages, plasma cells, and infrequently neutrophils. Importantly, severe necrotizing hepatic lesions were often observed in Alouatta sp. (howler monkeys), whereas Callithrix sp. (common marmosets) had nearly no hepatic changes. Moderate to severe hepatic necrosis was present in 21/23 (91%) of the YFV-positive Alouatta sp. compared with 10/29 (34%) of the YFV-positive Callithrix sp. (P < .0001; odds ratio = 20). Similarly, hepatitis was more intense in Alouatta sp. compared with Callithrix sp. Furthermore, the frequency of YFV infection was significantly higher in Alouatta sp. compared with Callithrix sp. or Sapajus sp. (capuchin monkeys). Therefore, these data support the notion that Alouatta sp. is highly susceptible to infection and YFV-induced lesions, whereas Callithrix sp. is susceptible to infection but has a lower frequency of YFV-induced lesions.

Host range and susceptibility to Toxoplasma gondii infection in captive neotropical and Old-world primates.

BACKGROUND: Toxoplasmosis is an important disease affecting captive non-human primates. The goal of this study was to assess the seroprevalence and pathological findings of toxoplasmosis in different species of captive primates. METHODS: Six captive neotropical primates died naturally due to Toxoplasma gondii infection and were necropsied. Tissue samples were evaluated by histopathology and immunohistochemistry. Serum samples from 57 captive neotropical and Old-world primates housed at the Belo Horizonte zoological garden were analyzed by indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and indirect hemagglutination assay (IHA). RESULTS: Neotropical primates had lesions compatible with toxoplasmosis with immunolabeled intralesional T gondii. All Old-World primates (10/10), but only three neotropical primates (3/47), all belonging to the Sapajus apella species (3/6), were serologically positive. CONCLUSIONS: Our results suggest a higher susceptibility of neotropical primates to toxoplasmosis. However, this study also supports the hypothesis that Sapajus apella may be naturally resistant.

Systemic infection by Spencermartinsiella sp. in a Nile crocodile (Crocodylus niloticus) / Infecção sistêmica por Spencermartinsiella sp. em um crocodilo do Nilo (Crocodylus niloticus)

A male adult crocodile (Crocodylus niloticus) was diagnosed with systemic yeast infection. Histologically, there were extensive areas of necrosis in the lung, which were associated with a diffuse severe lympho-plasmo-histiocytic inflammatory infiltrate, with numerous multinucleated giant cells, and myriads of intralesional pseudo-hyphae and yeast like organisms within distended foveolae. Necrotic foci were also observed in the mucosa of the digestive tract, trachea, tunica intima of arteries, liver, and heart, with a marked inflammatory lympho-histiocytic infiltrate, with large numbers of epithelioid macrophages and giant cells, and intralesional and intravascular pseudo-hyphae and yeast-like organisms. Oval yeast structures with 4 to 6 µm in diameter and 5 to 8 µm thick paralleled-wall pseudo-hyphae were observed in PAS or GMS stained sections. PCR with DNA template extracted from paraffin embedded tissues amplified the D1/D2 domains of the large subunit rRNA gene, which was sequenced and found to be identical to sequences of a new species, isolated from rotting wood in Brazil, of the genus Spencermartinsiella, which its closest relative is Spencermartinsiella cellulosicola.(AU)

Um crocodilo macho adulto (Crocodylus niloticus) foi diagnosticado com infecção fúngica sustêmica. Histologicamente, havia extensas áreas de necrose no pulmão, que estavam associadas com infiltrado inflamatório linfo-plasmo-histiocitário, com numerosas células gigantes multinucleadas e miríade de pseudo-hifas e organismos leveduriformes intralesionais, dentro de favéolas distendidas. Focos necróticos também foram observados na mucosa do trato digestório, traquéia, túnica íntima de artérias, fígado e coração, com acentuado infiltrado inflamatório linfo-histiocitário, com grande número de macrófagos epitelioides e células gigantes e hifas e organismos leveduriformes intralesionais e intravasculares. Cortes corados por PAS e GMS evidenciaram estruturas leveduriformes ovais com 4 a 6 µm de diâmetro e pseudo-hifas de paredes espessas e paralelas com 5 a 8 µm. PCR realizado com DNA extraído de material parafinizado amplificou os domínios D1/D2 da subunidade maior do gene rRNA, cuja sequencia foi idêntica a sequências de uma nova espécie, isolada no Brasil de madeira em decomposição, do gênero Spencermartinsiella, cuja espécie mais próxima é Spencermartinsiella cellulosicola.(AU)

Etiologic diagnosis of bovine infectious abortion by PCR / Diagnóstico etiológico de aborto infeccioso bovino por PCR

Infectious abortion is a significant cause of reproductive failure and economic losses in cattle. The goal of this study was to detect nucleic acids of several infectious agents known to cause abortion including Arcanobacterium pyogenes, Bovine Herpesvirus 1, Brucella abortus, Campylobacter fetus subsp. venerealis, Chlamydophila abortus, Leptospira sp., Listeria monocytogenes, Salmonella sp., Mycoplasma bovis, Mycoplasma bovigenitalium, Neospora caninum, and Tritrichomonas foetus. Tissue homogenates from 42 fetuses and paraffin-embedded tissues from 28 fetuses and 14 placentas/endometrium were included in this study. Brucella abortus was detected in 14.2 percent (12/84) of the samples. Salmonella sp. DNA was amplified from 2 fetuses, and there was one positive for Neospora caninum, and another for Listeria monocytogenes. This PCR-based approach resulted in identification of the etiology in 19 percent of samples, or 20 percent if considered fetal tissues only.

Aborto infeccioso é uma causa significativa de falhas reprodutivas e perdas econômicas na bovinocultura. O objetivo deste estudo foi detectar ácidos nucleicos de vários agentes infecciosos reconhecidos como causadores de aborto, incluindo-se Arcanobacterium pyogenes, Herpesvirus bovino tipo 1, Brucella abortus, Campylobacter fetus subsp. venerealis, Chlamydophila abortus, Leptospira sp., Listeria monocytogenes, Salmonella sp., Mycoplasma bovis, Mycoplasma bovigenitalium, Neospora caninum e Tritrichomonas foetus. Homogenados de tecidos de 42 fetos e tecidos incluídos em parafina de 28 fetos e 14 placentas/endométrio foram incluídos neste estudo. Brucella abortus foi detectada em 14,2 por cento (12/84) das amostras. DNA de Salmonella sp. foi amplificado de dois fetos e houve um feto positivo para Neospora caninum e outro para Listeria monocytogenes. Essa metodologia baseada em PCR resultou na identificação da etiologia em 19 por cento das amostras ou 20 por cento se considerados somente os tecidos fetais.

Anti-Sarcocystis neurona immunostaining associated with equine protozoal myeloencephalitis in Brazil

A retrospective study (1942 to 2005) of histopathological lesions included samples of central nervous system (SNC) from 203 animals in the Equidae family. A total of 42.4 percent of these samples had significant pathological changes, which were classified as inflammatory (62.8 percent), degenerative (25.6 percent), circulatory (10.5 percent), and neoplasic (1.1 percent) lesions. Immunohistochemistry anti-Sarcocystis neurona antigens was performed in all the cases with inflammatory changes (54), of which one of the case of encephalitis resulted positive to immunostaining. Although evidence of EPM (Equine Protozoal Myeloencephalitis) has been previously reported in Brazil, to the best of our knowledge, this is the first report in which characteristic EPM lesion was associated with anti-S. neurona immunostaining in Brazil.

Em um estudo retrospectivo (de 1942 a 2005), amostras do sistema nervoso central de 203 eqüídeos foram avaliadas para a presença de alterações histológicas. Dessas amostras, 42,4 por cento apresentaram alguma lesão histopatológica significativa, das quais foram classificadas como alterações inflamatórias (62,8 por cento), degenerativas (25,6 por cento), circulatórias (10,5 por cento) e neoplásicas (1,1 por cento). Fragmentos de SNC dos 54 animais com alterações inflamatórias foram avaliados para detecção de antígenos de Sarocystis neurona pela técnica de imunoistoquímica, que foi positiva em um caso de encefalite em eqüino. Embora haja registros de MPE no Brasil, este é o primeiro caso confirmado imunoistoquimicamente.

Cholelithiasis with atrophy of the right lateral hepatic lobe in a horse

A 22 year-old horse developed cholelithiasis with marked atrophy of the right lateral hepatic lobe. The horse had a history of intermittent colic since three years of age, and one of the first episodes of colic was associated with icterus. The size of the right lateral hepatic lobe was extremely reduced. There was a large choledocholith in the common hepatic duct, and several hepatoliths and choleliths in the intra- and extra-hepatic billiary ducts. Microscopically, there was severe atrophy of the right lobe with diffuse proliferation of connective tissue and billiary ducts. The left lateral lobe had peri-portal fibrosis with proliferation of billiary ducts, and billiary stasis. Chemical analysis of the calculi detected amorphous and triple phosphate, bilirubin, calcium, and iron.

Um cavalo de 22 anos de idade desenvolveu quadro de colelitíase severa com atrofia do lobo lateral direito. O animal tinha histórico de cólica recorrente, desde os três anos de idade, sendo que um dos primeiros episódios de cólica foi acompanhado de icterícia. O lobo hepático lateral direito estava extremamente diminuído de volume. Havia um grande coledocólito localizado no ducto hepático comum e inúmeros hepatólitos e colélitos nos ductos biliares intra e extra-hepáticos. Microscopicamente, foi observada atrofia acentuada do lobo direito, com proliferação difusa de tecido conjuntivo fibroso e de ductos biliares. O lobo lateral esquerdo apresentava fibrose periportal difusa associada à proliferação acentuada de ductos biliares e estase biliar. Análise química das concreções detectou fosfato triplo e amorfo, bilirrubina, cálcio e ferro.

Aspergilose em avestruz (Struthio camelus) no Brasil / Aspergillosis in an ostrich (Struthio camelus) in Brazil

Criatórios de avestruz têm se tornado comuns no Brasil, mas por se tratar de espécie exótica, as informações sobre as doenças desses animais no nosso ambiente são escassas. Um avestruz de cinco meses de idade apresentou tosse, anorexia, perda de peso, dispnéia discreta, temperatura corporal normal e morreu oito dias após o início dos sinais clínicos. Macroscopicamente foram observados nódulos múltiplos no pulmão e nos sacos aéreos. Histolopatogicamente, observou-se pneumonia granulomatosa e necrosante multifocal com hifas ramificadas e septadas intralesionais com características morfológicas de Aspergillus sp. Nos sacos aéreos, além das hifas e processo inflamatório adjacente haviam vários micélios com conidióforos na superfície interna. Foi isolado Aspergillus fumigatus dos tecidos afetados. De acordo com os achados histopatológicos e micológicos firmou-se o diagnóstico de pneumonia e aerossaculite micótica severa causada por Aspergillus fumigatus. Com base nas informações disponíveis na literatura, esse é o primeiro caso de aspergilose em avestruz documentado no Brasil.