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1.
Vet Res ; 52(1): 30, 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33618766

RESUMO

Host proteins interacting with pathogens are receiving more attention as potential therapeutic targets in molecular medicine. Streptococcus suis serotype 2 (SS2) is an important cause of meningitis in both humans and pigs worldwide. SS2 Enolase (Eno) has previously been identified as a virulence factor with a role in altering blood brain barrier (BBB) integrity, but the host cell membrane receptor of Eno and The mechanism(s) involved are unclear. This study identified that SS2 Eno binds to 40S ribosomal protein SA (RPSA) on the surface of porcine brain microvascular endothelial cells leading to activation of intracellular p38/ERK-eIF4E signalling, which promotes intracellular expression of HSPD1 (heat-shock protein family D member 1), and initiation of host-cell apoptosis, and increased BBB permeability facilitating bacterial invasion. This study reveals novel functions for the host-interactional molecules RPSA and HSPD1 in BBB integrity, and provides insight for new therapeutic strategies in meningitis.


Assuntos
Barreira Hematoencefálica , Células Endoteliais/metabolismo , Fosfopiruvato Hidratase/metabolismo , Proteínas Ribossômicas/metabolismo , Infecções Estreptocócicas/veterinária , Streptococcus suis/metabolismo , Animais , Apoptose , Técnicas de Cocultura , Células Endoteliais/microbiologia , Fator de Iniciação 4E em Eucariotos/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Camundongos , Ligação Proteica , Sorogrupo , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Streptococcus suis/patogenicidade , Suínos , Doenças dos Suínos/microbiologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
2.
Dis Aquat Organ ; 142: 197-201, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331287

RESUMO

Streptococcus iniae causes high mortality in cultured and wild fish stocks globally. Since the first report in captive Amazon river dolphins Inia geoffrensis in 1976, it has emerged in finfish across all continents except Antarctica. In March 2016, an estimated 17000 fish were observed dead and dying along a remote 70 km stretch of the Kimberley coastline north of Broome, Western Australia. Affected species included finfish (lionfish Pterois volitans, angelfish Pomacanthus sp., stripey snapper Lutjanus carponotatus, sand bass Psammoperca waigiensis, yellowtail grunter Amniataba caudavittata, damselfish Pomacentridae sp.), flatback sea turtles Natator depressus, and olive (Aipysurus laevis) and black-ringed (Hydrelaps darwiniensis) sea snakes. Moribund fish collected during the event exhibited exophthalmia and abnormal behaviour, such as spiralling on the surface or within the water column. Subsequent histopathological examination of 2 fish species revealed bacterial septicaemia with chains of Gram-positive cocci seen in multiple organs and within brain tissue. S. iniae was isolated and identified by bacterial culture, species-specific PCR, Matrix-Assisted Laser Desorption Ionisation Time-Of-Flight (MALDI-TOF) and biochemical testing. This is the first report of S. iniae associated with a major multi-species wild marine fish kill in Australia. Extreme weather events in the region including a marked decrease in water temperatures, followed by an extended period of above-average coastal water temperatures, were implicated as stressors potentially contributing to this outbreak.


Assuntos
Doenças dos Peixes , Infecções Estreptocócicas , Animais , Austrália , Doenças dos Peixes/epidemiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/veterinária , Streptococcus iniae , Austrália Ocidental/epidemiologia
3.
Dis Aquat Organ ; 141: 53-69, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32940251

RESUMO

Streptococcus iniae is a Gram-positive, opportunistically zoonotic bacterium infective to a wide variety of farmed and wild fish species worldwide. Outbreaks in wild fish can have detrimental environmental and cultural impacts, and mortality events in aquaculture can result in significant economic losses. As an emerging or re-emerging pathogen of global significance, understanding the coalescing factors contributing to piscine streptococcosis is crucial for developing strategies to control infections. Intraspecific antigenic and genetic variability of S. iniae has made development of autogenous vaccines a challenge, particularly where the diversity of locally endemic S. iniae strains is unknown. This study genetically and phenotypically characterized 11 S. iniae isolates from diseased wild and farmed fish from North America, Central America, and the Caribbean. A multilocus sequence analysis (MLSA) scheme was developed to phylogenetically compare these isolates to 84 other strains of Streptococcus spp. relevant to aquaculture. MLSA generated phylogenies comparable to established genotyping methods, and isolates formed distinct clades related to phenotype and host species. The endothelial Oreochromis mossambicus bulbus arteriosus cell line and whole blood from rainbow trout Oncorhynchus mykiss, Nile tilapia Oreochromis niloticus, and white sturgeon Acipenser transmontanus were used to investigate the persistence and virulence of the 11 isolates using in vitro assays. In vivo challenges using an O. niloticus model were used to evaluate virulence by the intragastric route of infection. Isolates showed significant differences (p < 0.05) in virulence and persistence, with some correlation to genogroup, establishing a basis for further work uncovering genetic factors leading to increased pathogenicity.


Assuntos
Doenças dos Peixes , Infecções Estreptocócicas/veterinária , Streptococcus iniae , Animais , Região do Caribe , América Central , Tipagem de Sequências Multilocus/veterinária , Índias Ocidentais
4.
Proc Natl Acad Sci U S A ; 117(41): 25378-25385, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32958634

RESUMO

Our study reveals a hitherto overlooked ecological threat of climate change. Studies of warming events in the ocean have typically focused on the events' maximum temperature and duration as the cause of devastating disturbances in coral reefs, kelp forests, and rocky shores. In this study, however, we found that the rate of onset (Ronset), rather than the peak, was the likely trigger of mass mortality of coral reef fishes in the Red Sea. Following a steep rise in water temperature (4.2 °C in 2.5 d), thermally stressed fish belonging to dozens of species became fatally infected by Streptococcus iniae Piscivores and benthivores were disproportionately impacted whereas zooplanktivores were spared. Mortality rates peaked 2 wk later, coinciding with a second warming event with extreme Ronset The epizootic lasted ∼2 mo, extending beyond the warming events through the consumption of pathogen-laden carcasses by uninfected fish. The warming was widespread, with an evident decline in wind speed, barometric pressure, and latent heat flux. A reassessment of past reports suggests that steep Ronset was also the probable trigger of mass mortalities of wild fish elsewhere. If the ongoing increase in the frequency and intensity of marine heat waves is associated with a corresponding increase in the frequency of extreme Ronset, calamities inflicted on coral reefs by the warming oceans may extend far beyond coral bleaching.


Assuntos
Mudança Climática , Recifes de Corais , Doenças dos Peixes/mortalidade , Peixes , Infecções Estreptocócicas/veterinária , Animais , Antozoários , Surtos de Doenças/veterinária , Doenças dos Peixes/microbiologia , Resposta ao Choque Térmico , Oceano Índico , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Streptococcus iniae/isolamento & purificação , Fatores de Tempo
5.
Vet J ; 262: 105473, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32792091

RESUMO

This study aimed to evaluate the effects of chronic subclinical mastitis (CSM) on milk production and component yields in dairy cows. A total of six herds located in the Midwest area of São Paulo State, Brazil were selected. Herds were visited once every 2 weeks to measure milk yield and to collect milk samples from lactating Holstein cows. Milk samples were collected at two stages (1 and 2), and each stage comprised three milk samplings. In stage 1, a total of 117 of 647 cows were diagnosed with CSM based on at least two of three repeated somatic cell counts (SCC) > 2000,000 cells/mL and positive bacterial milk culture results (BC). Cows with CSM were selected for the second stage. In stage 2, selected cows had quarter sampling aseptically collected for BC analyses prior to milking, and quarter milk yield was measured. Milk components (total protein, fat, lactose, and total solids) were measured using mid-infrared spectroscopy. Mammary quarters were considered healthy if all three repeated SCC results were ≤ 200,000 cells/mL and no bacterial growth was detected on BC. All quarters with positive bacterial growth were classified as having (non-chronic) subclinical mastitis when only one of three SCC results were > 200,000 cells/mL, and CSM when at least two of three SCC results were > 200,000 cells/mL. The effects of CSM by type of pathogen on milk and components yield were assessed using a linear mixed model. Mammary quarters with CSM caused by major pathogens had milk loss of 1.1 kg/quarter milking in comparison to healthy quarters. Milk losses were 0.8 and 1.3 kg/quarter milking when CSM was caused by Staphylococcus aureus or environmental streptococci, respectively. In addition, healthy quarters produced more milk components than quarters with CSM caused by major pathogens. Minor pathogens causing CSM (non-aureus staphylococci and Corynebacterium spp.) had no effect on milk yield. Quarters with CSM had lower milk and component yields when compared with healthy quarters. Milk losses varied according to the type of pathogen and were higher when associated with major pathogens such as S. aureus and environmental streptococci compared with healthy quarters.


Assuntos
Mastite Bovina/fisiopatologia , Leite/química , Leite/metabolismo , Infecções Estafilocócicas/veterinária , Infecções Estreptocócicas/veterinária , Animais , Infecções Assintomáticas , Brasil , Bovinos , Doença Crônica/veterinária , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/fisiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/fisiopatologia , Streptococcus/fisiologia
6.
J Vet Sci ; 21(4): e57, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32735095

RESUMO

BACKGROUND: Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. OBJECTIVES: This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. METHODS: A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. RESULTS: Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. CONCLUSION: This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.


Assuntos
Farmacorresistência Bacteriana/genética , Infecções Estreptocócicas/veterinária , Streptococcus/efeitos dos fármacos , Doenças dos Suínos/diagnóstico , Animais , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/veterinária , Tipagem de Sequências Multilocus/veterinária , República da Coreia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/microbiologia , Streptococcus/genética , Suínos , Doenças dos Suínos/microbiologia
7.
Acta Vet Scand ; 62(1): 36, 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32580735

RESUMO

BACKGROUND: Streptococcus suis is a major cause of meningitis, arthritis, and pneumonia in pigs worldwide, and an emerging pathogen in humans. In Sweden, S. suis has previously received little attention but has in recent years become increasingly recognized as affecting the pig production. The aim of the present study was to investigate the occurrence, serotypes and antimicrobial susceptibility of S. suis in Swedish grower pigs from herds with and without reported S. suis associated disease, as well as possible associations between S. suis associated disease and selected environmental and production factors. Swab samples were taken from the tonsils of clinically healthy 8-13-week-old grower pigs from ten case herds and ten control herds. Isolates were cultured, identified using MALDI-TOF MS, and serotyped using latex agglutination. The antimicrobial susceptibility of 188 isolates was tested using broth microdilution. Production data was gathered and environmental parameters were measured on the farms. RESULTS: Streptococcus suis was isolated from 95% of the sampled pigs in both the case and the control herds. Serotypes 3, 4, 5, 7, 9, 10, 11, 15, 16, and 17-34 were detected, although a majority of the isolates (81.5%) were non-typeable. There was less diversity among the serotypes isolated from the case herds than among those from the control herds; four and nine different serotypes, respectively. Isolates resistant to penicillin (3.8%) were reported for the first time in Sweden. Tetracycline resistance was common (88.4%). No association was noted between the production and the environmental factors investigated, and the carriership of S. suis. CONCLUSIONS: The carriership of S. suis was found to be higher in clinically healthy Swedish pigs than previously estimated, and for the first time, the presence of Swedish isolates resistant to penicillin was reported. Many of the most commonly disease-associated serotypes, e.g. serotypes 2, 9, 3, and 7, were detected in healthy grower pigs although further studies are needed to investigate the virulence of these isolates.


Assuntos
Infecções Estreptocócicas/veterinária , Streptococcus suis/isolamento & purificação , Doenças dos Suínos/epidemiologia , Animais , Antibacterianos/farmacologia , Feminino , Incidência , Testes de Sensibilidade Microbiana/veterinária , Sorogrupo , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus suis/classificação , Streptococcus suis/efeitos dos fármacos , Sus scrofa , Suécia/epidemiologia , Suínos , Doenças dos Suínos/microbiologia
8.
J Vet Diagn Invest ; 32(4): 565-571, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32532177

RESUMO

Investigations of 2 cases of high mortality in cull sows and feeder pigs from a buying station in Ohio and cull sows at an abattoir in Tennessee were conducted at the Iowa State University Veterinary Diagnostic Laboratory. The animals were presented as weak, lethargic, and some with high fever. Rapidly escalating mortality was reported to be as high as 30-50% within groups at the buying station over 8-10 d, and 30-40% over 5-7 d at the abattoir. Splenomegaly and red lymph nodes were the most consistent macroscopic findings, with scant fibrinous polyserositis observed in one sow. The microscopic lesions of vasculitis, fibrin thrombi, fibrinosuppurative polyserositis, and intralesional bacteria were consistent with acute bacterial septicemia. Bacterial culture isolated Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) from multiple organs, including spleen, lung, and kidney. PCR tests were negative for African swine fever virus, classical swine fever virus, Erysipelothrix rhusiopathiae, porcine reproductive and respiratory syndrome virus, porcine circovirus 2, and Salmonella spp. Porcine circovirus 3 was inconsistently detected at low levels by PCR, with a lack of associated lesions. Next-generation sequencing identified S. zooepidemicus and porcine partetravirus in the serum sample of the feeder pig from the buying station. Phylogenetic analysis of the szP gene indicated that the S. zooepidemicus isolates from Ohio and Tennessee are in genotype VI. We conclude that the cause of these high mortality events in swine was S. zooepidemicus septicemia.


Assuntos
Sepse/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus equi/isolamento & purificação , Doenças dos Suínos/mortalidade , Animais , Feminino , Genótipo , Ohio/epidemiologia , Filogenia , Sepse/microbiologia , Sepse/mortalidade , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Streptococcus equi/classificação , Sus scrofa , Suínos , Doenças dos Suínos/microbiologia , Tennessee/epidemiologia
9.
Acta Vet Scand ; 62(1): 26, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493395

RESUMO

BACKGROUND: Streptococcus halichoeri infections have been reported in grey seals, a European badger, a Stellar sea lion and humans, but its presence in companion and fur animals is unknown. Since 2010, S. halichoeri-like bacteria (SHL) have been isolated from fur animals and dogs in Finland. Our aim was to retrospectively investigate laboratory records for SHL from canine and fur animal infections, characterize the isolates and compare their genetic relatedness in relation to three reference strains: CCUG 48324T, originating from a grey seal, and strains 67100 and 61265, originally isolated from humans. RESULTS: A total of 138 and 36 SHLs from canine and fur animal infections, respectively, were identified in the laboratory records. SHL was commonly associated with skin infections, but rarely as the only species. A set of 49 canine and 23 fur animal SHLs were further characterized. MALDI-TOF confirmed them as being S. halichoeri. The growth characteristics were consistent with the original findings, but isolates were catalase positive. In total, 17 distinct API 20 Strep patterns were recorded among all 75 isolates tested, of which pattern 5563100 was the most common (n = 30). Antimicrobial resistance to erythromycin and clindamycin was common in canine isolates, but rare in fur animal isolates. Three clusters were observed by PFGE, and 16S rRNA sequencing revealed 98.1-100% similarities with the human strains and 98.1-99.5% with the seal strain. A phylogenetic tree of concatenated 16S rRNA and rpoB revealed closely related isolates with two clades. Fifteen canine isolates were identical to the human strains based on concatenated 16S rRNA and rpoB sequencing. CONCLUSIONS: Streptococcus halichoeri appears to be quite a common bacterial species in the skin of dogs and fur animals. The clinical significance of S. halichoeri is uncertain, as it was rarely isolated as a monoculture. No apparent temporal or spatial clustering was detected, but isolates from different sources were genetically very similar. Because many canine isolates were genetically similar to the human reference strains, transmission between dogs and humans may be possible. WGS sequencing of strains from different sources is needed to further investigate the epidemiology and virulence of S. halichoeri.


Assuntos
Doenças do Cão/microbiologia , Raposas , Vison , Cães Guaxinins , Infecções Estreptocócicas/veterinária , Streptococcus/genética , Animais , Cães , Filogenia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Estudos Retrospectivos , Streptococcus/química , Streptococcus/classificação , Streptococcus/fisiologia
11.
J Appl Microbiol ; 129(5): 1157-1162, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32396231

RESUMO

AIMS: The aims of the study were to evaluate whether epidemic strains of streptococcosis infected tilapia can be isolated and identified from dead fish for epidemiological investigation. METHODS AND RESULTS: Firstly, tilapias were inoculated with a lethal dose (1 × 108  CFU per fish) of Streptococcus agalactiae and brain tissues were harvested for bacteriological examination and qPCR assay 3, 12, 24 and 48 h postdeath. Streptococcus agalactiae was the only dominant bacterium cultivated on the brain heart infusion (BHI) plate and the bacterial load was about 107  CFU per mg. Secondly, tilapia were killed via ice water shock and immersed either in an aquarium containing 2·27 × 104  CFU per ml S. agalactiae or in a pond with streptococcosis outbreak. Streptococcus agalactiae failed to grow on the BHI plate but were identified (<6 × 102  CFU per mg) via qPCR assay. Finally, an epidemiological investigation of streptococcosis was conducted in the main tilapia breeding areas of South China. A total of 387 tilapia samples were collected including 24 suspected healthy, 35 moribund and 328 dead fish. The achieved detection rates were 0, 100 and 94·82% via bacteriological examination, and 0, 100 and 98·78% via qPCR assay respectively. The concentration of S. agalactiae in brain tissues ranged between 105 and 107  CFU per mg. CONCLUSIONS: Streptococcus agalactiae can survive for 48 h in the brain of dead fish. Dead tilapia can be a useful alternative for epidemiological investigation when the diagnostic analysis of moribund fish is unavailable or impractical. SIGNIFICANCE AND IMPACT OF THE STUDY: This detection method expands the sampling range, reduces the difficulty of sample collection and improves efficiency. Consequently, this method provides an alternative for epidemiological investigation of tilapia streptococcosis.


Assuntos
Carga Bacteriana/métodos , Ciclídeos/microbiologia , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/isolamento & purificação , Animais , Encéfalo/microbiologia , China/epidemiologia , Monitoramento Epidemiológico/veterinária , Reação em Cadeia da Polimerase , Infecções Estreptocócicas/microbiologia
12.
Vet Microbiol ; 243: 108653, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32273000

RESUMO

Porcine circovirus type 2 (PCV-2) and Streptococcus suis (S. suis) are common pathogens in pigs. Both pathogens are associated with the porcine respiratory disease complex. Clinically, coinfection of PCV-2 and S. suis are often detected in pigs with respiratory symptoms, while interactions between the two pathogens during coinfection and the coinfection pathogenesis are poorly understood. In this study, a piglet model coinfected with PCV-2 and Streptococcus suis serotype 2 (SS2) was established; coinfection of piglets increased the contents of SS2 in blood, and piglets showed more severe pneumonia, myocarditis and arthritis. Peripheral blood mononuclear cells (PBMCs) were collected and coinfected piglets showed high expression levels of inflammatory cytokines and TLR2, TLR4, while levels of CD4, CD8 and MHC II were reduced. In addition, in order to further explore the mechanisms of coinfection induced cytokine overexpression, an in vitro model of coinfection with PCV-2 and SS2 was established using cells of the porcine monocytic line 3D4/21. Similar to the in vivo results,coinfected cells exhibited increased expression of the cytokines IL-6, IL-8, TNF-α and the receptors TLR2, TLR4, while they showed a lower expression of MHC II than cells infected with SS2 alone. Furthermore, in coinfected 3D4/21 cells, both MAPK and NF-κB signaling pathways were activated, and the increased expression of IL-8 was related to TLR4. In general, coinfection with PCV-2 and SS2 exacerbated the inflammatory response and probably impaired macrophage antigen presentation, resulting in immune dysregulation and increasing the severity of host infection.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/patogenicidade , Coinfecção/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus suis/patogenicidade , Animais , Infecções por Circoviridae/imunologia , Circovirus/imunologia , Coinfecção/imunologia , Citocinas/genética , Citocinas/imunologia , Sorogrupo , Infecções Estreptocócicas/imunologia , Streptococcus suis/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Virulência
13.
Vet Microbiol ; 243: 108638, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32273017

RESUMO

Strangles, caused by Streptococcus equi subspecies equi (S. equi) is an infectious disease of horses with worldwide distribution, but there are limited data available regarding strain variation using whole genome sequencing among and within outbreaks in the United States (US), and how US isolates compare with S. equi isolated globally. To address this knowledge-gap, we compared the whole genomes of 54 S. equi isolates from Texas and Kentucky and those of 230 publicly available sequences of S. equi isolates collected from other countries. Our results show that despite minimal variation among isolates within an outbreak some mutations do occur among individual outbreak isolates. Some S. equi strains from the US are closely related to S. equi isolates from other countries, likely reflecting international dissemination of isolates. Collectively, these data improve our understanding of phenotypic and genotypic variation of isolates within an outbreak, and the international distribution of S. equi. We also identify a novel variant of the S. equi M-protein, and observed cases of strangles that were caused by the modified-live vaccine but that were not recognized as vaccine-associated at the time of clinical sample submission.


Assuntos
Surtos de Doenças/veterinária , Doenças dos Cavalos/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus/genética , Sequenciamento Completo do Genoma , Animais , Proteínas de Bactérias/genética , Variação Genética , Genótipo , Cavalos/microbiologia , Internacionalidade , Kentucky/epidemiologia , Mutação , Filogenia , Análise de Sequência de DNA , Texas/epidemiologia
14.
Acta Vet Scand ; 62(1): 12, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131871

RESUMO

BACKGROUND: Ovine laryngeal chondritis is a rare entity of sheep in the USA, Great Britain, New Zealand and Iceland, but has not been reported in Germany so far. Here, two German cases are reported. CASE PRESENTATION: Two rams showed severe and progressive signs of dyspnea. Endoscopically, a severe bilateral swelling of the larynx was identified in both rams. Due to poor prognosis and progression of clinical signs one ram was euthanized, while the other ram died overnight. In both cases, a necrosuppurative laryngitis and chondritis of arytenoid cartilages was found at necropsy. Fusobacterium necrophorum and Streptococcus ovis were isolated from the laryngeal lesion in one animal. CONCLUSIONS: This is the first report of ovine laryngeal chondritis in continental Europe. This entity should be considered a differential diagnosis for upper airway disease in sheep.


Assuntos
Doenças das Cartilagens/veterinária , Infecções por Fusobacterium/veterinária , Doenças da Laringe/veterinária , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/patologia , Infecções Estreptocócicas/veterinária , Animais , Autopsia , Doenças das Cartilagens/diagnóstico , Doenças das Cartilagens/microbiologia , Doenças das Cartilagens/patologia , Eutanásia Animal , Evolução Fatal , Infecções por Fusobacterium/diagnóstico , Infecções por Fusobacterium/patologia , Fusobacterium necrophorum/isolamento & purificação , Alemanha , Doenças da Laringe/diagnóstico , Doenças da Laringe/microbiologia , Doenças da Laringe/patologia , Laringe/microbiologia , Laringe/patologia , Masculino , Ovinos , Doenças dos Ovinos/microbiologia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/patologia , Streptococcus/isolamento & purificação
15.
Res Vet Sci ; 130: 68-72, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32146377

RESUMO

Modified-live virus (MLV) vaccines derived from highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) were wildly used in China, which resulted in the emergence of MLV-like strains in pigs. Previous studies demonstrated that secondary bacterial infection could enhance HP-PRRSV infection-mediated inflammatory responses, but it is unknown whether early bacterial infection could enhance the HP-PRRSV MLV-like infection-mediated pathological reaction. In this paper, to gain the evidence for infection of pigs with MLV-like strains in China, we firstly analyzed the genetic characterization of the HP-PRRSV MLV-like isolate (TJxq1701) and further evaluated whether the early Streptococcus suis infection synergizes HP-PRRSV MLV-like infection-mediated pathological reaction. Our results showed that the whole genome of TJxq1701 shared the highest homology with JXA1-P80 and a total of 16 amino acids residues unique to JXA1-P80 in ORF1a, ORF1b, GP2, GP3, GP4, and GP5 were found in the corresponding locations. The results of infection experiments in pigs revealed that TJxq1701 caused transitional fever, moderate respiratory clinical sign and microscopic lung lesions in piglets, but early infection with low virulence Streptococcus suis serotype 2 (SS2) exhibited seriously clinical signs, including high fever, anorexia, and respiratory distress, leading to 60% mortality within four weeks in comparison with alone infected group. Taken together, our findings reveal that early bacterial infection could enhance the HP-PRRSV MLV-like infection-mediated pathological reaction, which provide an important clue for understanding that streptococcus infection increases the pathogenicity of MLV-like virus and a new thought for prevention and control of PRRSV.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Infecções Estreptocócicas/veterinária , Streptococcus suis/fisiologia , Doenças dos Suínos/virologia , Animais , Sorogrupo , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Suínos , Doenças dos Suínos/microbiologia , Vacinas Atenuadas , Virulência
16.
J Fish Dis ; 43(4): 485-490, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32100309

RESUMO

Outbreaks of an infectious disease affecting cultured white sturgeon (Acipenser transmontanus) were investigated. Clinical signs included erratic swimming, arching of the back and mortality. Necropsy findings included poorly demarcated yellow to dark-red and friable lesions in the epaxial muscle, ulcerative skin lesions and haemorrhages in the swim bladder and coelomic wall. Histological evaluation revealed areas of necrotizing and heterophilic myositis with aggregates of bacterial cocci. The lumen of blood vessels in the dermis, under ulcerated areas, and in the posterior kidney, was occluded by fibrin thrombi. Aggregates of Gram-positive cocci were observed in the muscle lesions and within the fibrin thrombi in the dermis and kidney. Genetically homogeneous Streptococcus iniae strains were recovered from affected fish from different outbreaks. The isolates shared high degree of similarity at gene locus (gyrB) with previously characterized S. iniae from cultured fish in California, confirming the emergence of this particular strain of S. iniae in US aquaculture.


Assuntos
Surtos de Doenças/veterinária , Doenças dos Peixes/epidemiologia , Peixes , Miosite/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus iniae/fisiologia , Animais , Aquicultura , Doenças dos Peixes/microbiologia , Miosite/epidemiologia , Miosite/microbiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Estados Unidos/epidemiologia
17.
Fish Shellfish Immunol ; 99: 274-283, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32058098

RESUMO

luxS-mediated autoinducer 2 (AI-2)-dependent quorum sensing (QS) has been demonstrated to affect many bacterial phenotypes, including virulence. Streptococcus agalactiae harbors a functional luxS gene required for the biosynthesis of AI-2. In this study, we investigated the regulation effect and mechanism of the luxS/AI-2 QS system in the pathogenicity of the piscine S. agalactiae strain GD201008-001. We found that inactivation of luxS caused a marked decrease in biofilm formation, hemolytic activity, antiphagocytosis and intracellular survival of S. agalactiae. Except for hemolytic activity, the altered phenotypes due to the luxS deletion were AI-2-independent. Further investigation indicated that high levels of the proinflammatory cytokines IL-1ß and IL-6 could be induced in macrophages co-incubated with the luxS deletion mutant and synthetic AI-2, single or combined. Also, the results of tilapia infection showed that inactivation of luxS significantly decreased the virulence of S. agalactiae but upregulated the expression of cytokines in spleens and brains. Increased proinflammatory effects of the luxS mutant were restored in the luxS complemented strain but could not be restored by AI-2 addition. All the findings suggest that luxS is involved in virulence-associated phenotypes and immunological evasion of S. agalactiae, and furthermore, this involvement is mostly AI-2-independent. This study will provide valuable insights into our understanding of the role of the LuxS/AI-2 QS system in the pathogenesis of S. agalactiae.


Assuntos
Proteínas de Bactérias/metabolismo , Liases de Carbono-Enxofre/metabolismo , Homosserina/análogos & derivados , Lactonas/metabolismo , Streptococcus agalactiae/metabolismo , Streptococcus agalactiae/patogenicidade , Animais , Proteínas de Bactérias/genética , Biofilmes , Liases de Carbono-Enxofre/genética , Sobrevivência Celular , Ciclídeos , Citocinas/genética , Citocinas/metabolismo , Doenças dos Peixes/microbiologia , Deleção de Genes , Regulação da Expressão Gênica , Homosserina/genética , Homosserina/metabolismo , Camundongos , Mutação , Células RAW 264.7 , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/veterinária , Virulência
18.
Equine Vet J ; 52(6): 884-890, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32052491

RESUMO

BACKGROUND: Endoscopic examinations are essential for diagnosis and treatment of strangles (S equi infection) in horses. However, even after disinfection, endoscopes may retain viable bacteria or bacterial DNA. Twitches are commonly used during endoscopic examinations and can thus also potentially transmit the organism to other horses. OBJECTIVES: To evaluate the efficacy of different disinfectant methods to eliminate S equi from experimentally contaminated endoscopes and twitches and the effectiveness of field disinfection of endoscopes used in sampling carriers of S equi. STUDY DESIGN: Experimental contamination and observational field study. METHODS: One endoscope and 30 twitches were contaminated with standardised S equi broth solutions. The endoscope was disinfected following three protocols using various disinfectants for manual disinfection. A fourth protocol used an automated endoscope reprocessor (AER). The twitches (n = 30) were disinfected following eight different disinfecting protocols. Three endoscopes used in sampling for silent carriers were disinfected following a field-based protocol. After each protocol the endoscopes and twitches were sampled for S equi by culture and qPCR. RESULTS: Following experimental contamination all endoscope disinfection protocols, apart from 1/6 of the ethanol protocol were S equi culture negative. However, no endoscope disinfection protocol completely eliminated retention of S equi DNA. Field disinfection of endoscopes after sampling carriers yielded no culture positives and all but one (13/14) were qPCR negative. All twitches disinfected following experimental contamination were culture negative but sodium hypochlorite was the only disinfectant that completely eliminated detection of S equi DNA. MAIN LIMITATIONS: Experimental contamination may not reflect the numbers of S equi transferred to endoscopes or twitches during use on silent carriers and purulent secretions from infected horses may influence survival of S equi. CONCLUSIONS: While most disinfection methods appear to ensure removal of cultivable S equi, residual DNA can remain on both endoscopes and twitches.


Assuntos
Desinfetantes/farmacologia , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/prevenção & controle , Infecções Estreptocócicas/veterinária , Streptococcus equi , Animais , Desinfecção , Endoscópios , Cavalos
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