RESUMEN
Reannotation of the pathogenic Mycoplasma gallisepticum strain R(low) genome identified the hypothetical gene MGA_0329 as a homolog of the sialidase gene MS53_0199 of Mycoplasma synoviae strain MS53. Potent sialidase activity was subsequently quantitated in several M. gallisepticum strains. Because sialidase activity levels correlate significantly with differing M. synoviae strain virulence, we hypothesized this enzyme may also influence the virulence of M. gallisepticum. MGA_0329 was disrupted in strain R(low) to create mutants 6, 358 and P1C5, which resulted in the loss of sialidase activity in all three mutants. Chickens infected with the knockout mutants had significantly less severe (P<0.05) tracheal lesions and tracheal mucosal thickening than chickens infected with equal doses of strain R(low). Significantly fewer (P<0.05) CCU especially of strains 6 and P1C5 were recovered at necropsy. Mini-Tn4001tet plasmid pTF20 carrying a wild-type copy of MGA_0329 with its native promoter was used to complement the genetic lesion in strain P1C5. Three clones derived from P1C5, each having one copy of MGA_0329 stably transposed into a different site in its genome, expressed sialidase restored to wild-type activity levels (1.58×10(-8)U/CFU). Complementation of P1C5 with MGA_0329 did not restore it to wild-type levels of virulence, indicating that the contribution of sialidase to M. gallisepticum virulence is not straightforward.
Asunto(s)
Infecciones por Mycoplasma/veterinaria , Mycoplasma gallisepticum/enzimología , Mycoplasma gallisepticum/patogenicidad , Neuraminidasa/genética , Virulencia , Animales , Pollos/microbiología , Técnicas de Inactivación de Genes , Prueba de Complementación Genética , Mutagénesis Insercional , Infecciones por Mycoplasma/microbiología , Infecciones por Mycoplasma/patología , Mycoplasma gallisepticum/genética , Mycoplasma synoviae/enzimologíaRESUMEN
A novel siadenovirus was identified in the Sulawesi tortoise (Indotestudo forsteni). A group of 105 Sulawesi tortoises was obtained by the Turtle Survival Alliance. Many of the tortoises were in poor health. Clinical signs included anorexia, lethargy, mucosal ulcerations and palatine erosions of the oral cavity, nasal and ocular discharge, and diarrhea. Initial diagnostic tests included fecal testing for parasites, complete blood count and plasma biochemical analysis, mycoplasma serology, and polymerase chain reaction (PCR) testing for intranuclear coccidia and chelonian herpesvirus. Treatment included administration of antibiotics, antiparasitic medications, parenteral fluids, and nutritional support. Tissue samples from animals that died were submitted for histopathologic evaluation. Histopathologic examination revealed systemic inflammation and necrosis associated with intranuclear inclusions consistent with a systemic viral infection in 35 tortoises out of 50 examined. Fecal testing results and histopathologic findings revealed intestinal and hepatic amoebiasis and nematodiasis in 31 animals. Two of 5 tortoises tested by PCR were positive for Chlamydophila sp. Aeromonas hydrophila and Escherichia coli were cultured from multiple organs of 2 animals. The mycoplasma serology and PCR results for intranuclear coccidia and chelonian herpesvirus were negative. Polymerase chain reaction testing of tissues, plasma, and choanal/cloacal samples from 41 out of 42 tortoises tested were positive for an adenovirus, which was characterized by sequence analysis and molecular phylogenetic inference as a novel adenovirus of the genus Siadenovirus. The present report details the clinical and anatomic pathologic findings associated with systemic infection of Sulawesi tortoises by this novel Siadenovirus, which extends the known reptilian adenoviruses to the chelonians and extends the known genera of reptilian Adenoviridae beyond Atadenovirus to include the genus Siadenovirus.
Asunto(s)
Infecciones por Adenoviridae/veterinaria , Siadenovirus/genética , Siadenovirus/aislamiento & purificación , Tortugas , Infecciones por Adenoviridae/epidemiología , Infecciones por Adenoviridae/patología , Infecciones por Adenoviridae/virología , Secuencia de Aminoácidos , Animales , Huesos/ultraestructura , Huesos/virología , ADN Polimerasa Dirigida por ADN/química , ADN Polimerasa Dirigida por ADN/genética , ADN Polimerasa Dirigida por ADN/metabolismo , Indonesia/epidemiología , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa/veterinaria , Bazo/ultraestructura , Bazo/virología , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismoRESUMEN
Iridoviruses infect food and ornamental fish species from a wide range of freshwater to marine habitats across the globe. The objective of the current study was to characterize an iridovirus causing systemic infection of wild-caught Pterapogon kauderni Koumans 1933 (Banggai cardinalfish). Freshly frozen and fixed specimens were processed for histopathologic evaluation, transmission electron microscopic examination, virus culture, molecular virologic testing, microbiology, and in situ hybridization (ISH) using riboprobes. Basophilic granular cytoplasmic inclusions were identified in cytomegalic cells often found beneath endothelium, and hexagonal virus particles typical of iridovirus were identified in the cytoplasm of enlarged cells by transmission electron microscopy. Attempts at virus isolation in cell culture were unsuccessful; however, polymerase chain reaction (PCR)-based molecular testing resulted in amplification and sequencing of regions of the DNA polymerase and major capsid protein genes, along with the full-length ATPase gene of the putative iridovirus. Virus gene sequences were then used to infer phylogenetic relationships of the P. kauderni agent to other known systemic iridoviruses from fishes. Riboprobes, which were transcribed from a cloned PCR amplification product from the viral genome generated hybridization signals from inclusions within cytomegalic cells in histologic sections tested in ISH experiments. To the authors' knowledge, this is the first report of a systemic iridovirus from P. kauderni. The pathologic changes induced and the genomic sequence data confirm placement of the Banggai cardinalfish iridovirus in the genus Megalocytivirus family Iridoviridae. The ISH provides an additional molecular diagnostic technique for confirmation of presumptive infections detected in histologic sections from infected fish.
Asunto(s)
Infecciones por Virus ADN/veterinaria , Enfermedades de los Peces/virología , Iridovirus/aislamiento & purificación , Perciformes/virología , Animales , Infecciones por Virus ADN/diagnóstico , Infecciones por Virus ADN/patología , Infecciones por Virus ADN/virología , ADN Viral/aislamiento & purificación , Enfermedades de los Peces/diagnóstico , Enfermedades de los Peces/patologíaRESUMEN
The treatment of HIV-related lymphomas is evolving in the era of HAART. Standard-dose chemotherapy and dose-intensive therapies appear to be feasible. Whether outcomes are improved with combination chemotherapy and HAART remains unclear. Efforts aimed at developing pathogenic-based therapies will continue as the mechanisms of HIV lymphomagenesis are elucidated.
Asunto(s)
Linfoma Relacionado con SIDA/tratamiento farmacológico , Linfoma Relacionado con SIDA/etiología , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Terapia Antirretroviral Altamente Activa , Manejo de la Enfermedad , Humanos , Linfoma Relacionado con SIDA/clasificación , Linfoma no Hodgkin , Terapia RecuperativaRESUMEN
The introduction of highly active antiretroviral therapy (HAART) has had a dramatic impact on the morbidity and mortality of individuals living with human immunodeficiency virus (HIV). In addition to contributing to dramatic declines in the incidence of several opportunistic infections, HAART is affecting the incidences of several acquired immunodeficiency syndrome (AIDS)-defining malignancies. The incidence of Kaposi's sarcoma (KS) and primary central nervous system lymphoma (PCNSL) has dropped precipitously since the introduction of HAART in 1995. Systemic non-Hodgkin's lymphoma (NHL) appears to be declining in incidence as well, but to a lesser degree than KS and PCNSL. On the contrary, the incidence of invasive cervical carcinoma has not significantly changed in the HAART era. The impact of HAART on the epidemiology of other HIV-associated malignancies, including Hodgkin's disease and anal carcinoma, remains unclear. Data regarding the impact of HAART on the natural history and treatment outcomes of HIV-associated malignancies are limited. The possibility of direct and indirect roles of HIV in HIV-related carcinogenesis suggests that antiretroviral therapy may be an important component of the treatment strategy for several HIV-related malignancies. Patients with HIV-NHL treated with HAART in addition to chemotherapy experience fewer intercurrent opportunistic infections. Furthermore, the simultaneous administration of HAART and chemotherapy does not appear to significantly increase toxicity. Whether the combination of HAART and standard therapy results in improved survival remains uncertain. This two-part article, which began in the April 2002 issue, analyzes the impact of HAART on the incidence, clinical course, and outcomes of each of the AIDS-related malignancies.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Neoplasias del Ano/complicaciones , Neoplasias del Ano/epidemiología , Neoplasias del Sistema Nervioso Central/epidemiología , Linfoma Relacionado con SIDA/epidemiología , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Ano/tratamiento farmacológico , Neoplasias del Sistema Nervioso Central/complicaciones , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Femenino , Enfermedad de Hodgkin/complicaciones , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/epidemiología , Humanos , Linfoma Relacionado con SIDA/tratamiento farmacológico , Masculino , Neoplasias del Cuello Uterino/tratamiento farmacológicoRESUMEN
The introduction of highly active antiretroviral therapy (HAART) has had a dramatic impact on the morbidity and mortality of individuals living with human immunodeficiency virus (HIV). In addition to contributing to declines in the incidence of several opportunistic infections, HAART is affecting the incidences of several acquired immunodeficiency syndrome (AIDS)-defining malignancies. The incidence of Kaposi's sarcoma (KS) and primary central nervous system lymphoma (PCNSL) has dropped precipitously since the introduction of HAART in 1995. Systemic non-Hodgkin's lymphoma (NHL) appears to be declining in incidence as well, but to a lesser degree than KS and PCNSL. On the contrary, the incidence of invasive cervical carcinoma has not significantly changed in the HAART era. The impact of HAART on the epidemiology of other HIV-associated malignancies, including Hodgkin's disease and anal carcinoma, remains unclear. Data regarding the impact of HAART on the natural history and treatment outcomes of HIV-associated malignancies are limited. The possibility of direct and indirect roles of HIV in HIV-related carcinogenesis suggests that antiretroviral therapy may be an important component of the treatment strategy for several HIV-related malignancies. Patients with HIV-NHL treated with HAART in addition to chemotherapy experience fewer intercurrent opportunistic infections. Furthermore, the simultaneous administration of HAART and chemotherapy does not appear to significantly increase toxicity. Whether the combination of HAART and standard therapy results in improved survival remains uncertain. This two-part article, which will conclude in the May 2002 issue, analyzes the impact of HAARTon the incidence, clinical course, and outcomes of each of the AIDS-related malignancies.