RESUMO
Piscine lactococcosis is a significant threat to cultured and wild fish populations worldwide. The disease typically presents as a per-acute to acute hemorrhagic septicemia causing high morbidity and mortality, recalcitrant to antimicrobial treatment or management interventions. Historically, the disease was attributed to the gram-positive pathogen Lactococcus garvieae. However, recent work has revealed three distinct lactococcosis-causing bacteria (LCB)-L. garvieae, L. petauri, and L. formosensis-which are phenotypically and genetically similar, leading to widespread misidentification. An update on our understanding of lactococcosis and improved methods for identification are urgently needed. To this end, we used representative isolates from each of the three LCB species to compare currently available and recently developed molecular and phenotypic typing assays, including whole-genome sequencing (WGS), end-point and quantitative PCR (qPCR) assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), API 20 Strep and Biolog systems, fatty acid methyl ester analysis (FAME), and Sensititre antimicrobial profiling. Apart from WGS, sequencing of the gyrB gene was the only method capable of consistent and accurate identification to the species and strain level. A qPCR assay based on a putative glycosyltransferase gene was also able to distinguish L. petauri from L. garvieae/formosensis. Biochemical tests and MALDI-TOF MS showed some species-specific patterns in sugar and fatty acid metabolism or protein profiles but should be complemented by additional analyses. The LCB demonstrated overlap in host and geographic range, but there were relevant differences in host specificity, regional prevalence, and antimicrobial susceptibility impacting disease treatment and prevention. IMPORTANCE: Lactococcosis affects a broad range of host species, including fish from cold, temperate, and warm freshwater or marine environments, as well as several terrestrial animals, including humans. As such, lactococcosis is a disease of concern for animal and ecosystem health. The disease is endemic in European and Asian aquaculture but is rapidly encroaching on ecologically and economically important fish populations across the Americas. Piscine lactococcosis is difficult to manage, with issues of vaccine escape, ineffective antimicrobial treatment, and the development of carrier fish or biofilms leading to recurrent outbreaks. Our understanding of the disease is also widely outdated. The accepted etiologic agent of lactococcosis is Lactococcus garvieae. However, historical misidentification has masked contributions from two additional species, L. petauri and L. formosensis, which are indistinguishable from L. garvieae by common diagnostic methods. This work is the first comprehensive characterization of all three agents and provides direct recommendations for species-specific diagnosis and management.
Assuntos
Doenças dos Peixes , Infecções por Bactérias Gram-Positivas , Lactococcus , Lactococcus/genética , Lactococcus/isolamento & purificação , Lactococcus/classificação , Animais , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/veterinária , Peixes/microbiologia , Sequenciamento Completo do Genoma , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The global ornamental fish trade carries important risk factors for spreading pathogens between different countries and regions, not only for ornamental fish but also for cultured fish and even other animal species. In the current study, we reported the capacity of Aeromonas veronii and A. hydrophila isolated from ornamental fish to experimentally infect the reared Amazonian fish Colossoma macropomum. For this, those bacteria were identified, and a primary characterization was performed. Fish were inoculated with 0.1 mL of increasing concentrations of A. hydrophila or A. veronii (C1 = 1 × 102; C2 = 1.8 × 104; C3 = 2.1 × 106; C4 = 2.4 × 108 bacterial cells per mL) in the coelomic cavity. In the control group, fish received the same volume of sterile saline solution (0.9 %). Fish presented petechiae, skin suffusions, and mortality rates up to 100 % according to the inoculum concentration. Histopathologically, fish presented necrosis with karyolysis, loss of the cytoplasmic delimitation of cells of the renal tubules and hepatocytes, hemorrhage, cellular edema, and the presence of bacterial cells. The LD50-96h of A. veronii on C. macropomum was estimated at 2.4 × 106 CFU mL-1 and of A. hydrophila at 1.408 × 105 CFU mL-1. The results demonstrated that it is possible that Aeromonas species isolated from ornamental fish affect C. macropomum, causing similar clinical signs and lesions. This shows the importance of promoting risk control measures worldwide regarding the trade of ornamental fish.
Assuntos
Aeromonas , Caraciformes , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Animais , Aeromonas veronii , Dose Letal Mediana , Fatores de Risco , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
Pasturella multocida (P. multocida), a gram-negative bacterium, has long been a focus of interest in animal health because of its capacity to cause different infections, including hemorrhagic septicemia. Yaks, primarily found in high-altitude environments, are among the several livestock animals affected by these bacteria. Yaks are essential to the socioeconomic life of the people who depend on them since they are adapted to the cold and hypoxic conditions of highland environments. Nevertheless, these terrains exhibit a greater incidence of P. multocida despite the severe environmental complications. This predominance has been linked to the possible attenuation of the yak's immunological responses in such circumstances and the evolution of some bacterial strains to favor survival in the respiratory passages of the animals. Moreover, these particular strains threaten other cattle populations that interact with yaks, which might result in unanticipated outbreaks in areas previously thought to be low risk. Considering these findings, designing and executing preventative and control strategies suited explicitly for these distinct biological environments is imperative. Through such strategies, yaks' health will be guaranteed, and a larger bovine population will be safeguarded against unanticipated epidemics. The current review provides thorough insights that were previously dispersed among several investigations. Its distinct method of connecting the ecology of yaks with the dynamics of infection offers substantial background information for further studies and livestock management plans.
RESUMO
Viral hemorrhagic septicemia virus (VHSV) poses a significant threat to the aquaculture industry, prompting the need for effective preventive measures. Here, we developed an inactivated VHSV and revealed the molecular mechanisms underlying the host's protective response against VHSV. The vaccine was created by treating VHSV with 0.05 % formalin at 16 °C for 48 h, which was determined to be the most effective inactivation method. Compared with nonvaccinated fish, vaccinated fish exhibited a remarkable increase in survival rate (99 %) and elevated levels of serum neutralizing antibodies, indicating strong immunization. To investigate the gene changes induced by vaccination, RNA sequencing was performed on spleen samples from control and vaccinated fish 14 days after vaccination. The analysis revealed 893 differentially expressed genes (DEGs), with notable up-regulation of immune-related genes such as annexin A1a, coxsackievirus and adenovirus receptor homolog, V-set domain-containing T-cell activation inhibitor 1-like, and heat shock protein 90 alpha class A member 1 tandem duplicate 2, indicating a vigorous innate immune response. Furthermore, KEGG enrichment analysis highlighted significant enrichment of DEGs in processes related to antigen processing and presentation, necroptosis, and viral carcinogenesis. GO enrichment analysis further revealed enrichment of DEGs related to the regulation of type I interferon (IFN) production, type I IFN production, and negative regulation of viral processes. Moreover, protein-protein interaction network analysis identified central hub genes, including IRF3 and HSP90AA1.2, suggesting their crucial roles in coordinating the immune response elicited by the vaccine. These findings not only confirm the effectiveness of our vaccine formulation but also offer valuable insights into the underlying immunological mechanisms, which can be valuable for future vaccine development and disease management in the aquaculture industry.
Assuntos
Bass , Doenças dos Peixes , Septicemia Hemorrágica Viral , Novirhabdovirus , Vacinas de Produtos Inativados , Vacinas Virais , Animais , Novirhabdovirus/imunologia , Vacinas Virais/imunologia , Vacinas Virais/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Septicemia Hemorrágica Viral/prevenção & controle , Septicemia Hemorrágica Viral/imunologia , Bass/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/prevenção & controle , Imunidade Inata , Genótipo , Vacinação/veterinária , Imunização/veterináriaRESUMO
Viral hemorrhagic septicemia virus (VHSV) poses a significant threat to global aquaculture, prompting ongoing efforts to identify potential drug candidates for disease prevention. Coumarin derivatives have recently emerged as a promising class of compounds effective against rhabdoviruses, which severely impact the aquaculture industry. In this study, we assessed the anti-VHSV activity of umbelliferone (7-hydroxycoumarin) in fathead minnow (FHM) cells and olive flounder Paralichthys olivaceus. Umbelliferone exhibited an EC50 of 100 µg/mL by reducing cytopathic effect, with a maximum cytotoxicity of 30.9 % at 750 µg/mL. Mechanistic analyses via a time-course plaque reduction assay revealed that direct incubation with the virus for 1 h resulted in 97.0 ± 1.8 % plaque reduction, showing excellent direct virucidal activity. Pretreatment for 4 h resulted in a 33.5 ± 7.8 % plaque reduction, which increased with longer incubation times. Cotreatment led to a 33.5 ± 2.9 % plaque reduction, suggesting interference with viral binding, whereas postinfection treatment proved less effective. Umbelliferone was prophylactically administered to the olive flounder through short-term (3 days) and long-term (14 days) medicated feeding, followed by a 4-day postinfection period. Short-term administration at 100 mg/kg body weight (bw)/day resulted in the highest relative percent survival (RPS) of 56 %, whereas long-term administration achieved a maximum RPS of 44 % at 30 mg/kg bw/day. Umbelliferone administration delayed mortality at these doses. Additionally, umbelliferone significantly inhibited the expression of the VHSV N gene during viral challenge, with no observed toxic effects in fish up to an administration dose of 30 mg/kg bw/day for 28 days. Our findings suggest that the protective mechanism of short-term administration of 100 mg umbelliferone against VHSV infection may involve the overexpression of TLR2, MDA5, STAT1, and NF-κB at 24 h postinfection (hpi). IL-8 and IFN II expression was upregulated, whereas TNF-α, IL-1ß, and IFN I expression was suppressed at 24 hpi. The upregulation of ISG15 at 48 hpi may contribute to the inhibition of VHSV replication, whereas the downregulation of Caspase 3 expression at 96 hpi suggests a possible inhibition of virus-induced apoptosis at later infection stages. Overall, umbelliferone exhibited anti-VHSV activity through multiple mechanisms, with the added advantage of convenient administration via medicated feed.
Assuntos
Antivirais , Novirhabdovirus , Umbeliferonas , Animais , Umbeliferonas/farmacologia , Antivirais/farmacologia , Novirhabdovirus/fisiologia , Novirhabdovirus/efeitos dos fármacos , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Linguado/imunologia , Septicemia Hemorrágica Viral/virologia , Septicemia Hemorrágica Viral/imunologia , Linhagem CelularRESUMO
BACKGROUND: Chromobacterium is a genus of fourteen species with validly published names, most often found in soil and waters in tropical and subtropical regions around the world. The most well-known species of the genus, C. violaceum, occasionally causes clinically relevant infections; cases of soft tissue infections with septicemia and fatal outcomes have been described. CASE PRESENTATION: Here, we present a clinical case report of a 79-year-old man from Sweden with a soft-tissue infection and septicemia. The pathogen was identified as a strain of Chromobacterium species, but not C. violaceum. The patient was treated with clindamycin and ciprofloxacin and recovered well. CONCLUSIONS: This case report demonstrates the potential of Chromobacterium species as infectious agents in immunocompetent patients. It also indicates the existence of a novel species.
Assuntos
Infecções por Bactérias Gram-Negativas , Sepse , Masculino , Humanos , Idoso , Chromobacterium , Suécia , Sepse/diagnóstico , Sepse/tratamento farmacológico , Sepse/microbiologia , Ciprofloxacina/uso terapêutico , Clindamicina/uso terapêutico , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
Mycobacterium ulcerans ecovar Liflandii (MuLiflandii) was identified as the causative agent of mycobacteriosis in a research colony of Zaire dwarf clawed frogs (Hymenochirus boettgeri) at the University of Michigan. Clinical presentation included lethargy, generalized septicemia, cutaneous granulomas, coelomic effusion, and acute mortality. Identification of the mycobacterial species was based on molecular, microbiological, and histopathologic characteristics. These findings indicate that MuLiflandii is a primary cause of morbidity and mortality in Zaire dwarf clawed frogs and should be considered in the differential diagnosis of sepsis and coelomic effusion in amphibians. Mycobacterial speciation is important given the variability in pathogenesis within the family Mycobacteriaceae and the implications for both animal and human health as potential zoonoses. The Zaire dwarf clawed frog is a species common in the pet trade, and these findings provide consideration for this pathogen as a potentially important public health concern. This is the first report of MuLiflandii infection in the genus Hymenochirus and illustrates the diagnostic challenges of differentiating among both mycolactone-producing mycobacteria and Mycobacterium marinum. Furthermore, we demonstrate the utility of environmental sampling for this pathogen within the tank system, suggesting this mode of sampling could replace the need for direct frog surveillance.
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Infecções por Mycobacterium não Tuberculosas , Mycobacterium ulcerans , Animais , Infecções por Mycobacterium não Tuberculosas/veterinária , Infecções por Mycobacterium não Tuberculosas/patologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium ulcerans/isolamento & purificação , Anuros/microbiologiaRESUMO
BACKGROUND: Sepsis is one of the major causes of morbidity and mortality among pediatric patients throughout the world. The varying microbiological pattern of sepsis warrants the need for researches on the causative organisms and their antimicrobial susceptibility pattern. The epidemiology of neonatal and pediatric sepsis in Ethiopia is under-research. The objective of this study was to evaluate the burden of bacterial pathogens and their antimicrobial susceptibility patterns among children suspected of sepsis. METHODS: An institutional-based prospective cross-sectional study was conducted on 370 pediatric(age birth-15 years) patients suspected of sepsis at the University of Gondar Comprehensive Specialized hospital from December 2020 to November 2021. Blood samples were collected aseptically and inoculated into Tryptone Soya Broth for culture. The organisms grown were identified by standard microbiological methods and subjected to antibiotic susceptibility testing by modified Kirby-Bauer disk diffusion method recommended by Clinical laboratory and standard institute. Methicillin resistance was confirmed using Cefoxitin disk diffusion method. Data entry and analysis were done using Statistical Package for Social Sciences (SPSS) version 26 software. A p-value less than 0.05 at 95% confidence interval was considered statically significant. RESULTS: Out of the total 370 study subjects, 21.6% (80/370) of them were culture positive. Of these, 43 (53.8%) and 37 (46.3%) were Gram-positive and Gram-negative bacterial pathogens, respectively. The most prevalent Gram-positive bacterial isolate was Staphylococcus aureus (n = 24; 30%) and coagulase negative staphylococci (n = 7; 8.8%). Among the Gram-negative bacterial isolates, the leading bacteria was Klebsiella pneumoniae (n = 20; 25%) followed by Escherichia coli (n = 7; 8.8%). Clindamycin, Chloramphenicol, Gentamicin and Ciprofloxacin were the most effective antibiotics against Gram-positive bacterial isolates while Amikacin, Meropenem and Chloramphenicol were effective against Gram-negative pathogens. Methicillin resistance was detected in 45.8% of Staphylococcus aureus. Multi-drug resistance (MDR) antimicrobial susceptibility pattern was observed in 76% of the bacterial isolates. CONCLUSION: Gram positive bacteria were the predominant isolates among pediatric sepsis cases and most of the bacterial isolates showed MDR. Staphylococcus aureus and Klebsiella pneumoniae were frequently isolated bacteria. The high prevalence of drug resistance warrants rational use of antibiotics and the need for regular antibiotic susceptibility surveillance studies.
Assuntos
Testes de Sensibilidade Microbiana , Sepse , Humanos , Etiópia/epidemiologia , Criança , Pré-Escolar , Lactente , Estudos Transversais , Adolescente , Sepse/microbiologia , Sepse/epidemiologia , Sepse/tratamento farmacológico , Masculino , Estudos Prospectivos , Feminino , Recém-Nascido , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Hospitais Universitários , Farmacorresistência Bacteriana MúltiplaRESUMO
Infections by Erysipelothrix rhusiopathiae occur in domestic animals and cause the disease known as 'erysipelas'. The ubiquity of Erysipelothrix spp. makes infection possible in a wide range of vertebrates and invertebrates. Cetaceans are highly susceptible to erysipelas, especially those under human care. The number of cases documented in wild cetaceans is low, the pathogenesis is incompletely understood, and the full spectrum of lesions is not well defined. The possible serotypes and species of the genus that can cause disease are unknown. In October 2022, a common bottlenose dolphin Tursiops truncatus stranded in Vilassar de Mar (Catalonia) showing skin lesions consistent with 'diamond skin disease', a characteristic lesion of erysipelas shared by swine and cetaceans. Necropsy was performed following standardized procedures, and multiple samples were taken for histopathology and bacteriology. Erysipelothrix sp. grew in pure culture in many tissue samples. Genetic characterization by multi-locus sequence analysis identified the species as E. rhusiopathiae. Histologically, the main lesions were an intense suppurative vasculitis of leptomeningeal arteries and veins with abundant intramural Gram-positive bacilli and meningeal hemorrhages. Meningeal lesions were considered the cause of death. The affected skin showed moderate suppurative dermatitis. Herein we document a case of erysipelas in a Mediterranean common bottlenose dolphin with unusual lesions in the leptomeningeal vessels and marked skin tropism. To our knowledge, this is the first case of severe brain involvement in erysipelas in a cetacean. We also provide a review of available cases in wild cetaceans, to highlight the characteristics of the disease and improve future diagnosis.
Assuntos
Golfinho Nariz-de-Garrafa , Erisipela , Infecções por Erysipelothrix , Erysipelothrix , Animais , Encéfalo , Erisipela/veterinária , Infecções por Erysipelothrix/microbiologiaRESUMO
Aeromonas septicemia still represents a serious challenge facing the global aquaculture sector. In the present study, Aeromonas caviae and A. veronii were isolated from four diseased European seabass (Dicentrarchus labrax) farms experiencing a high mortality rate. Diseased fish showed haemorrhages on the external body surface with exophthalmia, cataracts, scale desquamation, skin ulcers and fin erosions. The most common post-mortem findings were congested internal organs, particularly the liver and posterior kidney. Twenty-eight A. Veronii and 11 A. caviae isolates were identified biochemically by the Vitek 2 system and then confirmed by PCR and phylogenetic analysis. Hemolysin (hlyA) and aerolysin (aer) were the most abundant virulence genes in the recovered isolates, followed by cytotoxic enterotoxin (act) and heat-stable enterotoxin (ast). A. caviae was more virulent than A. veronii for D. labrax fingerlings as LD50 ranging between (>1 × 108 -6.2 × 107 ) for A. veronii and (2.9 × 107 -8.3 × 107 ) for A. caviae. The sensitivity test indicated the effectiveness of norfloxacin, doxycycline and oxytetracycline against the tested isolates. Serum cortisol significantly increased in the infected groups, while catalase and glutathione peroxidase activities significantly decreased at 2 days post-infection (DPI) and then increased at 6 DPI. The presence of virulence genes was associated with bacterial pathogenicity expressed in fish mortality rate. Virulence genes also drastically affect cortisol levels more than catalase and glutathione peroxidase levels.
Assuntos
Aeromonas , Bass , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Animais , Virulência/genética , Catalase/genética , Genótipo , Filogenia , Hidrocortisona , Doenças dos Peixes/microbiologia , Enterotoxinas , Glutationa Peroxidase/genética , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
Background: Ventricular mural thrombi are rare occurrences and form one of the common mechanical complications of myocardial infarctions. They also occur in patients with nonischemic myocardial disorders and even in those devoid of cardiac diseases. Clinical detection often depends on the size of the thrombi. Aim: This study was aimed at ascertaining the etiopathogenesis of mural thrombi with a clinicopathologic correlation. Materials and Methods: This was a 12-year retrospective observational study reviewing the autopsy records of all cases showing ventricular mural thrombi. The location, size, morphology, and histologic appearances of the thrombi were noted. The cases, depending on the etiology, were categorized into myocardial ischemic (Group 1), myocardial nonischemic (Group 2), and non-myocardial (Group 3) causes. These features were correlated with the clinical settings. Results: There were 93 cases of mural thrombi with an almost equal sex distribution and a mean age of 45.9 years. The cause was ischemic heart disease in most of the patients (Group 1, 46.2%), while 21.5% and 32.3% of patients belonged to Group 2 and Group 3, respectively. Unlike the large and dominantly left ventricular thrombi seen in Group 1, the other two groups frequently had biventricular involvement, location in the intertrabecular spaces, and a high microscopic detection. Clinical diagnosis had been made in only 3.2% of patients. Thromboembolism was noted in other organs in 34.4% of the total cases. Conclusion: Ventricular thrombi should be ruled out in patients with evidence of systemic and/or pulmonary thromboembolism, even in those without any cardiac disorders.
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Cardiopatias , Infarto do Miocárdio , Tromboembolia , Trombose , Humanos , Pessoa de Meia-Idade , Cardiopatias/complicações , Masculino , FemininoRESUMO
Diseases that occur in silkworms include soft rot, hardening disease, digestive diseases, and sepsis. However, research on the causes of bacterial diseases occurring in silkworms and the resulting changes in the microbial community is lacking. Therefore, we examined the morphological characteristics of sepsis and changes in the microbial community between silkworms that exhibit a unique odor and healthy silkworms; thus, we established a relationship between disease-causing microorganisms and sepsis. After producing a 16S rRNA amplicon library for samples showing sepsis, we obtained information on the microbial community present in silkworms using next-generation sequencing. Compared to that in healthy silkworms, in silkworms with sepsis, the abundance of the Firmicutes phylum was significantly reduced, while that of Proteobacteria was increased. Serratia sp. was dominant in silkworms with sepsis. After bacterial isolation, identification, and reinfection through the oral cavity, we confirmed this organism as the disease-causing agent; its mortality rate was 1.8 times higher than that caused by Serratia marcescens. In summary, we identified a new causative bacterium of silkworm sepsis through microbial community analysis and confirmed that the microbial community balance was disrupted by the aberrant proliferation of certain bacteria.
Assuntos
Bombyx , Microbiota , Sepse , Animais , Serratia/genética , RNA Ribossômico 16S/genéticaRESUMO
The influence of non-opsonized and opsonized S. aureus 2879M and E. coli 321 strains on the total strength of interaction between the endothelial cell and neutrophil during the docking process was studied using in vitro model of experimental septicemia. We observed a decrease in the force and work of adhesion between receptors of neutrophils and endothelial cells under the influence of non-opsonized strains and further decrease in the affinity of single interactions between cells under the influence of opsonized S. aureus, which was compensated by an increase in the number of contacts, as well as an increase in the force of adhesion under the influence of opsonized E. coli compared to non-opsonized bacteria, which remained below the control level, while adhesion work reaches the control level. Thus, opsonization of S. aureus aggravates the "immunological uncoupling" between neutrophils and endothelial cells, while opsonization of E. coli reduces the pathological effect compared to non-opsonized bacteria.
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Células Endoteliais , Escherichia coli , Neutrófilos , Sepse , Staphylococcus aureus , Neutrófilos/imunologia , Neutrófilos/metabolismo , Escherichia coli/imunologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/patogenicidade , Sepse/imunologia , Sepse/microbiologia , Sepse/metabolismo , Sepse/patologia , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/microbiologia , Humanos , Fagocitose , Adesão Celular/imunologia , Proteínas Opsonizantes/metabolismo , Proteínas Opsonizantes/imunologia , Aderência Bacteriana , AnimaisRESUMO
During November 2021-May 2022, we identified 37 clinical cases of Streptococcus equi subspecies zooepidemicus infections in central Italy. Epidemiologic investigations and whole-genome sequencing showed unpasteurized fresh dairy products were the outbreak source. Early diagnosis by using sequencing technology prevented the spread of life-threatening S. equi subsp. zooepidemicus infections.
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Laticínios , Infecções Estreptocócicas , Streptococcus equi , Humanos , Surtos de Doenças , Itália/epidemiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/diagnóstico , Streptococcus equi/genéticaRESUMO
MicroRNAs (miRNAs) are small non-coding RNAs known to play a significant role in the regulation of gene expression in various living organisms including fish. MiR-155 is known to enhance immunity in cells and several reports have demonstrated the antiviral properties of miR-155 in mammals. In this study, we investigated the antiviral role of miR-155 in Epithelioma papulosum cyprini (EPC) cells with viral hemorrhagic septicemia virus (VHSV) infection. EPC cells were transfected with miR-155 mimic and then infected with VHSV at different MOIs (0.01 and 0.001). The cytopathogenic effect (CPE) was observed at 0, 24, 48, and 72 h post infection (h.p.i). CPE progression appeared at 48 h.p.i in mock groups (VHSV only infected groups) and the VHSV infection group transfected with miR-155 inhibitors. On the other hand, the groups transfected with the miR-155 mimic did not show any CPE formation after infection with VHSV. The supernatant was collected at 24, 48 and 72 h.p.i., and the viral titers were measured by plaque assay. The viral titers increased at 48 and 72 h.p.i in groups infected only with VHSV. In contrast, the groups transfected with miR-155 did not show any increase in the virus titer and had a similar titer to 0 h.p.i. Furthermore, the real-time RT-PCR of immune gene expression showed upregulation of Mx1 and ISG15 at 0, 24, and 48 h.p.i in groups transfected with miR-155, while the genes were upregulated at 48 h.p.i in groups infected only with VHSV. Based on these results, miR-155 can induce the overexpression of type I interferon-related immune genes in EPCs and inhibit the viral replication of VHSV. Therefore, these results suggest that miR-155 could possess an antiviral effect against VHSV.
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Carcinoma , Doenças dos Peixes , Septicemia Hemorrágica Viral , MicroRNAs , Novirhabdovirus , Animais , Antivirais , Linhagem Celular Tumoral , MicroRNAs/genética , MicroRNAs/metabolismo , Novirhabdovirus/fisiologia , Mamíferos/metabolismoRESUMO
Viral hemorrhagic septicemia virus (VHSV) causes a severe and often lethal infection in olive flounder (Paralichthys olivaceus) in Korea, resulting in mass mortality and substantial economic loss. As a potential prevention strategy for infectious viral diseases, this study aimed to evaluate the antiviral activity of three compounds (arctigenin [ARG], ribavirin [RBV], and ivermectin [IVM]) against VHSV infection in vitro and in vivo. In epithelioma papulosum cyprini cells, the expression of both VHSV glycoprotein (G) and nucleoprotein (N) genes were significantly suppressed by the three compounds in a dose-dependent manner (P < 0.05). Also, cell morphology and viability were maintained at the following concentrations: ARG 1.5 mg/L, RBV 2.5 mg/L, and IVM 10 mg/L. The fish that were treated with RBV (8.33 mg/kg) and IVM (0.25 mg/kg) before VHSV infection and those treated with IVM (0.25 mg/kg) after VHSV infection showed significant improvements in the survival rate, a reduction in the viral shedding rate, and downregulation of viral gene expression compared to those seen in fish with naïve VHSV infections. Furthermore, among the innate immune genes studied, persistent expression of Mx and upregulation of tumor necrosis factor-α gene expression in VHSV-infected fish treated with RBV and IVM revealed that these compounds might induce an immunostimulatory effect as one of their antiviral activities. Overall, this study supports the use of RBV and IVM as antiviral agents to control VHSV infections in olive flounder.
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Doenças dos Peixes , Linguado , Septicemia Hemorrágica Viral , Novirhabdovirus , Animais , Ribavirina/farmacologia , Antivirais/farmacologia , Ivermectina/farmacologia , Novirhabdovirus/fisiologiaRESUMO
Viral hemorrhagic septicemia causes considerable economic losses for Korea's olive flounder (Paralichthys olivaceus) aquaculture farms; therefore, effective antiviral agents for controlling viral hemorrhagic septicemia virus (VHSV) infection are imperative. The present study implemented a Box-Behnken design and cytopathic reduction assay to derive an optimized extract of Sanguisorba officinalis L. roots (OE-SOR) with maximum antiviral activity against VHSV. OE-SOR prepared under optimized extraction conditions (55% ethanol concentration at 50 °C for 5 h) exhibited potent antiviral activity against VHSV, with a 50% effective 0.21 µg/mL concentration and a 340 selective index. OE-SOR also showed direct virucidal activity in the plaque reduction assay. Administering OE-SOR to olive flounder exhibited substantial efficacies against VHSV infection. Fish receiving 100 mg/kg body weight/day of OE-SOR as a preventive (40.0%; p < 0.05) or therapeutic (44.4%; p < 0.05) exhibited a higher relative survival than the untreated VHSV-infected control group (mortalities of 100% and 90%, respectively). In addition, fish fed with OE-SOR (100 mg/kg body weight/day) for two weeks conveyed a significantly higher inflammatory cytokine expression (nuclear factor kappa-light-chain-enhancer of activated B cells [NF-κB], interleukin-1 beta [IL-1ß], and tumor necrosis factor-alpha [TNF-α]) than the control group one to two days post-administration. Moreover, no hematological or histological changes were observed in olive flounder treated with OE-SOR over four weeks. Liquid chromatography-quadrupole-time of flight tandem mass spectrometry and -triple quadrupole tandem mass spectrometry analyses identified ziyuglycoside I as a prominent OE-SOR constituent and marker compound (content: 14.5%). This study verifies that OE-SOR is an effective alternative for controlling viral hemorrhagic septicemia in olive flounder farms as it exhibits efficient in vivo anti-VHSV activity and increases innate immune responses.
Assuntos
Doenças dos Peixes , Linguado , Septicemia Hemorrágica Viral , Novirhabdovirus , Sanguisorba , Animais , Septicemia Hemorrágica Viral/prevenção & controle , Antivirais/farmacologia , Novirhabdovirus/fisiologia , Peso Corporal , Doenças dos Peixes/prevenção & controleRESUMO
BACKGROUND: Septicemia that leads to ocular involvement mostly presents as endophthalmitis or panophthalmitis. Contrarily, septicemia without intraocular involvement, known as hematogenous orbital cellulitis (HOC), involves only the orbit and is an extremely rare complication of septicemia and a rare type of orbital cellulitis. CASE PRESENTATION: Four male patients with septicemia presented with orbital involvement without intraocular infection were described in this study. They were 22 (case 1), 15 (case 2), 79 (case 3), and 30 (case 4) years old, with a mean age of 29.75 years. All patients were immunocompromised except for case 2. Cases 1 and 3 had a history of steroid use, whereas case 4 was in a post-chemotherapy myelosuppression phase. Septicemia in case 1 was community-acquired, cases 3 and 4 were hospital-acquired, and case 2 was secondary to acne squeezing. Blood cultures from cases 1, 2, and 3 were positive for Candida albicans, methicillin-resistant Staphylococcus aureus, and Klebsiella pneumoniae, respectively. Case 4 had negative cultures; however, next-generation sequencing reported the presence of Enterococcus faecalis and Rhizopus oryzae. Case 1 had right eye involvement, and both eyes were involved in the other three cases. According to Chandler's classification, case 1 was type 2, case 2 was type 2 (OD) and type 4 (OS), and cases 3 and 4 were type 1 orbital infections. All patients had eyelids erythema, and cases 1 and 2 had mildly decreased visual acuity, proptosis, and painful and restricted ocular motility. Hospital stays ranged from 13 to 43 days (mean, 24 days). All patients received systemic antibiotic therapy based on drug sensitivity and next-generation sequencing results, in combination with multidisciplinary treatment, resulting in complete recovery of ocular and systemic signs and symptoms; no ocular surgical interventions were performed. Extraocular muscle palsy was the last symptom to resolve. CONCLUSION: HOC is predominantly seen in immunocompromised individuals with a high proportion of hospital-acquired infections and positive cultures for pathogens. Infection control using systemic antibiotics targeted at the causative organism guarantees a favorable prognosis.
Assuntos
Infecções Oculares , Staphylococcus aureus Resistente à Meticilina , Celulite Orbitária , Sepse , Adulto , Humanos , Masculino , Antibacterianos/uso terapêutico , Infecções Oculares/tratamento farmacológico , Órbita , Celulite Orbitária/tratamento farmacológico , Sepse/complicações , Sepse/diagnóstico , Sepse/tratamento farmacológico , Adolescente , Adulto Jovem , IdosoRESUMO
BACKGROUND: Pneumococcal infections are common in children with nephrotic syndrome. Knowledge of the commonly available serotypes and antibiotic susceptibility will help in prevention and appropriate management of pneumococcal sepsis, especially in resource-limited countries. METHODS: Demographic, clinical, and laboratory data on children with nephrotic syndrome and pneumococcal infections were extracted from the electronic medical records. RESULTS: Sixty-three isolates of pneumococci obtained from 60 children with nephrotic syndrome, over a period of 14 years, were included in the study. This represented 18% of all pneumococcal infections occurring in children during the same period. Commonly available vaccines covered up to 58% of all the serotypes causing infection. Severe disease, with shock, intensive care admission and/or meningitis, was observed in 38% children and mortality was observed in 10%. Resistance to commonly used antibiotics was not observed, except for erythromycin. CONCLUSIONS: Pneumococcal sepsis was observed to be common in children with nephrotic syndrome and results in significant morbidity and mortality. Commonly used antibiotics were observed to be effective in management of the infections.
Assuntos
Bacteriemia , Síndrome Nefrótica , Infecções Pneumocócicas , Criança , Humanos , Lactente , Síndrome Nefrótica/complicações , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/epidemiologia , Países em Desenvolvimento , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Streptococcus pneumoniae , Antibacterianos/uso terapêutico , Vacinas Pneumocócicas/uso terapêuticoRESUMO
BACKGROUND: Septicemia is potentially fatal infection caused by pathogenic bacteria infiltrating the bloodstream, resulting in morbidity and mortality among Ethiopian hospital patients. Multidrug resistance is a therapeutic challenge in this patient population. There is an insufficiency data among hospitals in Ethiopia. Hence, this study aimed to assess the phenotypic bacterial isolates, antimicrobial susceptibility pattern, and associated factors among septicemia suspected patients. METHODS: Prospective cross-sectional study was conducted among 214 septicemia suspected patients from February to June 2021 at Debre Markos Comprehensive Specialized hospital in northwest, Ethiopia. Blood samples were collected aseptically and processed to identify bacterial isolates by using different standard microbiological procedures. Antimicrobial susceptibility pattern was performed using the modified Kirby Bauer disc diffusion on Mueller Hinton agar. Epi-data V4.2 was used to enter data and SPSS V25 for analysis. The variables were assessed using a bivariate logistic regression model with a 95% confidence interval, and declared statistically significant; P-value was < 0.05. RESULTS: The overall bacterial isolates was found 45/214 (21%) in this study. Gram-negative and positive bacteria were 25/45(55.6%), 20/45(44.4%) respectively. The most common bacterial isolates were Staphylococcus aureus12/45 (26.7%), Klebsiella pneumoniae 8/45(17.8%), Escherichia coli 6/45 (13.3%). Gram-negative bacteria showed susceptibility to amikacin (88%), meropenem, imipenem (76%) but, (92%) resistance to ampicillin, (85.7%) amoxicillin-clavulanic acid. S.aureus (91.7%) was resistance to Penicillin, (58.3%) cefoxitin and (75%) susceptible to ciprofloxacillin. S.pyogenes and S.agalactia were (100%) susceptible to Vancomacin. Multidrug resistance was found in 27/45(60%) of the bacterial isolates. The main predictors related to patients suspected of septicemia were prolonged hospitalization (AOR = 2.29, 95% CI: 1.18, 7.22), fever (AOR = 0.39, 95%CI: 0.18, 0.85) and length of hospital stay (AOR = 0.13, 95%CI: 0.02, 0.82). CONCLUSIONS: Incidence of bacterial isolates among septicemia suspected patients were high. The majority of the bacterial isolates were multidrug-resistant. To prevent antimicrobial resistance, specific antibiotic utilization strategy should be applied.