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1.
Microbiol Spectr ; 10(3): e0075822, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35638814

RESUMO

A previously reported method for evaluating the intracellular growth of Rhodococcus equi using enhanced green fluorescent protein is unsuitable for the quantitative evaluation of the entire sample because the signal can be detected only in the excitation region. Therefore, we created an autobioluminescent R. equi using luciferase (luxABCDE). First, we connected luxABCDE to the functional promoter PaphII and introduced it into the chromosomes of ATCC33701 and ATCC33701_P-. Luminescence was detected in both transformants, and a correlation between the bacterial number and luminescence intensity in the logarithmic phase was observed, indicating that luxABCDE is functionally and quantitatively expressed in R. equi. The luminescence of ATCC33701 was significantly higher than that of ATCC33701_P- at 24 h after infection with J774A.1. Next, RNA-Seq analysis of ATCC33701 to search for endogenous high-expression promoters resulted in the upstream sequences of RS29370, RS41760, and vapA being selected as candidates. Luminescence was detected in each transformant expressing the luxABCDE using these upstream sequences. We examined the luminescence intensity by coexpressing the frp gene, an enhancer of the luciferase reaction, with luxABCDE. The luminescence intensity of the coexpressing transformant was significantly enhanced in J774A.1 compared with the non-coexpressing transformant. Finally, we examined the luminescence in vivo. The luminescence signals in the organs peaked on the third day following the administration of ATCC33701 derivatives in mice, but no luminescence signal was detected when the ATCC33701_P- derivative was administered. The autologous bioluminescent method described herein will enhance the in vitro and in vivo quantitative analysis of R. equi proliferation. IMPORTANCE We established an autologous bioluminescent strain of R. equi and a method to evaluate its proliferation in vitro and in vivo quantitatively. This method overcomes the weakness of the fluorescence detection system that only measures the site of excitation light irradiation. It is expected to be used as an in vitro and in vivo growth evaluation method with excellent quantitative properties. In addition, it was suggested that the selection of a promoter that expresses luxABCDE could produce a luminescence with high intensity. Although this method needs further improvement, such as creating transformants that can maintain high luminescence intensity regardless of environmental changes such as temperature fluctuations, it is possible to observe bacterial growth over time in mice without killing them. Therefore, this method can be used to not only evaluate the pathogenicity of various wild and gene-deficient strains but also to screen preventive and therapeutic methods such as vaccines.


Assuntos
Infecções por Actinomycetales , Rhodococcus equi , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/prevenção & controle , Animais , Proteínas de Bactérias/genética , Camundongos , Rhodococcus equi/genética , Fatores de Virulência/genética
2.
Artigo em Inglês | MEDLINE | ID: mdl-35580017

RESUMO

A Gram-stain-positive coccus was isolated from the blood of a paediatric patient suffering from gastroenteritis. The taxonomic position of this catalase-positive, non-motile, non-spore-forming facultative anaerobe designated as strain MKL-02T was investigated using a polyphasic approach. Colonies grown on tryptic soy agar with 10 % sheep blood were circular, creamy yellow, and convex. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that this strain was most closely related to Arsenicicoccus bolidensis CCUG 47306T within the cluster of the genus Arsenicicoccus. Average nucleotide identity and digital DNA-DNA hybridization values between strain MKL-02T and A. bolidensis DSM 15745T, A. dermatophillus DSM 25571T and A. piscis DSM 22760T were 89.5 and 37.0 %, 79.6 and 22.4 %, and 75.9 and 21.0 %, respectively. The genomic size of strain MKL-02T was 3 423 857 bp with a 72.7 mol% G+C content. Growth was observed at 10-45 °C (optimum, 37-40 °C) and pH 6.0-10.0 (optimum, pH 7.0), in the presence of 0-10 % (w/v) NaCl (optimum, 0.5 %). Cells of strain MKL-02T were non-motile cocci and 0.50-0.60 µm long, as determined by transmission electron microscopy. The strain was catalase-positive and oxidase-negative. The major fatty acid type (>10 % of total) was C15 : 0. The polar lipid profile consisted of two unidentified phospholipids, three unidentified lipids and an unidentified aminophospholipid. The strain contained MK-8 (H4) as the predominant menaquinone. Based on phylogenetic and phenotypic considerations, it is proposed that strain MKL-02T be classified as a new species, named Arsenicicoccus cauae sp. nov. The type strain is MKL-02T (=NCCP 16967T=JCM 34624T).


Assuntos
Infecções por Actinomycetales , Actinomycetales , Gastroenterite , Actinomycetales/isolamento & purificação , Infecções por Actinomycetales/sangue , Infecções por Actinomycetales/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Catalase/genética , Criança , DNA Bacteriano/genética , Ácidos Graxos/química , Gastroenterite/sangue , Gastroenterite/microbiologia , Humanos , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ovinos
3.
J Vet Intern Med ; 36(3): 1146-1151, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35475581

RESUMO

BACKGROUND: Diagnostic accuracy of real-time, quantitative PCR (qPCR) assays to quantify virulent Rhodococcus equi using rectal swab samples has not been systematically evaluated. OBJECTIVE: To evaluate the accuracy of qPCR of rectal swab samples to differentiate foals with pneumonia from healthy foals of similar age from the same environment. ANIMALS: One hundred privately owned foals born in 2021 from 2 farms in New York. METHODS: An incident case-control study design was used. Rectal swabs were collected from all foals diagnosed with R. equi pneumonia at 2 horse-breeding farms (n = 47). Eligible pneumonia cases (n = 39) were matched by age to up to 2 healthy (n = 53) control foals; rectal swabs were collected from control foals on the day of diagnosis of the index case. DNA was extracted from fecal swabs and the concentration of virulent R. equi (ie, copy numbers of the virulence-associated protein A gene [vapA] per 100 ng fecal DNA) was estimated by qPCR. RESULTS: The area under the ROC curve for qPCR of fecal swabs was 83.7% (95% CI, 74.9-92.6). At a threshold of 14 883 copies of vapA per 100 ng fecal DNA, specificity of the assay was 83.0% (95% CI, 71.7-92.4) and sensitivity was 79.5% (95% CI, 66.7-92.3). CONCLUSIONS AND CLINICAL IMPORTANCE: Although fecal concentrations of virulent R. equi are significantly higher in pneumonic foals than healthy foals of similar age in the same environment, qPCR of rectal swabs as reported here lacks adequate diagnostic accuracy for clinical use.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Pneumonia , Rhodococcus equi , Infecções por Actinomycetales/diagnóstico , Infecções por Actinomycetales/veterinária , Animais , Estudos de Casos e Controles , Doenças dos Cavalos/diagnóstico , Cavalos/genética , Pneumonia/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária
4.
J Vet Intern Med ; 36(3): 1139-1145, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35322902

RESUMO

BACKGROUND: Intragastric administration of virulent Rhodococcus equi protects foals against subsequent experimental intrabronchial (IB) infection, but it is unknown whether R. equi naturally ingested by foals contributes to their susceptibility to pneumonia. HYPOTHESIS: Fecal concentration of virulent R. equi before IB infection with R. equi is positively associated with protection from pneumonia in foals. ANIMALS: Twenty-one university-owned foals. METHODS: Samples were collected from experimental studies. Five foals were gavaged with live, virulent R. equi (LVRE) at age 2 and 4 days; the remaining 16 foals were not gavaged with LVRE (controls). Fecal swabs were collected from foals at ages 28 days, immediately before IB infection. Foals were monitored for clinical signs of pneumonia, and fecal swabs were collected approximately 2 weeks after IB infection. Swabs were tested by quantitative PCR for concentration of virulent R. equi (ie, copy numbers of the virulence-associated protein A gene [vapA] per 100 ng fecal DNA). RESULTS: Fecal concentrations of virulent R. equi (vapA) before IB infection were significantly (P < .05) lower in control foals (25 copies/100 ng DNA [95% CI, 5 to 118 copies/100 ng DNA) that developed pneumonia (n = 8) than in healthy control foals (n = 8; 280 copies/100 ng DNA; 95% CI, 30 to 2552 copies/100 ng DNA) or those gavaged with LVRE (707 copies/100 ng DNA, 95% CI, 54 to 9207 copies/100 ng DNA). CONCLUSIONS AND CLINICAL IMPORTANCE: Greater natural ingestion of LVRE might contribute to protection against pneumonia among foals.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Pneumonia , Rhodococcus equi , Infecções por Actinomycetales/veterinária , Animais , Doenças dos Cavalos/diagnóstico , Cavalos , Humanos , Pneumonia/veterinária
5.
Equine Vet J ; 54(3): 481-494, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35188690

RESUMO

Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a common cause of disease and death for foals. The purpose of this narrative review was to summarise recent developments pertaining to the epidemiology, immune responses, treatment, and prevention of rhodococcal pneumonia of foals. Screening tests have been used to implement earlier detection and treatment of foals with presumed subclinical R. equi pneumonia to reduce mortality and severity of disease. Unfortunately, this practice has been linked to the emergence of antimicrobial-resistant R. equi in North America. Correlates of protective immunity for R. equi infections of foals remain elusive, but recent evidence indicates that innate immune responses are important both for mediating killing and orchestrating adaptive immune responses. A macrolide antimicrobial in combination with rifampin remains the recommended treatment for foals with R. equi pneumonia. Great need exists to identify which antimicrobial combination is most effective for treating foals with R. equi pneumonia and to limit emergence of antimicrobial-resistant strains. In the absence of an effective vaccine against R. equi, passive immunisation remains the only commercially available method for effectively reducing the incidence of R. equi pneumonia. Because passive immunisation is expensive, labour-intensive and carries risks for foals, great need exists to develop alternative approaches for passive and active immunisation.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Pneumonia Bacteriana , Rhodococcus equi , Infecções por Actinomycetales/tratamento farmacológico , Infecções por Actinomycetales/epidemiologia , Infecções por Actinomycetales/prevenção & controle , Infecções por Actinomycetales/veterinária , Animais , Antibacterianos/uso terapêutico , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/prevenção & controle , Cavalos , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/epidemiologia , Pneumonia Bacteriana/prevenção & controle , Pneumonia Bacteriana/veterinária
6.
BMC Urol ; 22(1): 25, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35197026

RESUMO

BACKGROUND: Fournier's gangrene (FG), a urological emergency with high mortality, is an infectious necrotizing fasciitis of the perineal and genital regions. The majority of FG is caused by polymicrobial organisms involving mixed aerobes and anaerobes but rarely reveals Actinomyces species. CASE PRESENTATION: We report a healthy 67-year-old Asian male who presented with rapidly progressive painful swelling of the scrotum. Clinically diagnosed with FG, the patient underwent an emergency radical debridement, followed by broad-spectrum antibiotics and negative pressure wound therapy. The identification of the causative microorganisms showed Actinomyces turicensis and the antibiotic treatment was adjusted accordingly. After wound bed preparation, we took split-thickness skin grafts to cover the scrotal wound. Active management to minimize faecal contamination was applied throughout the whole course of treatment and repair. The patient was satisfied with the outcome. This was an extremely rare case of A. turicensis as the main causative pathogen of FG. CONCLUSIONS: FG due to Actinomyces species is rarely reported, but we should still consider this pathogenic microorganism that has long been neglected.


Assuntos
Actinomycetaceae/isolamento & purificação , Infecções por Actinomycetales/complicações , Gangrena de Fournier/microbiologia , Escroto/patologia , Infecções por Actinomycetales/tratamento farmacológico , Idoso , Antibacterianos/uso terapêutico , Desbridamento , Gangrena de Fournier/cirurgia , Humanos , Masculino , Escroto/microbiologia , Escroto/cirurgia
7.
Emerg Infect Dis ; 28(3): 761-763, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35202530

RESUMO

To help clarify the clinical manifestations, diagnosis, and treatment for Whipple disease, we report a case of a man in China infected with Tropheryma whipplei. The patient had multiple subcutaneous nodules as the only manifestation, which was not consistent with the typical symptoms of T. whipplei infection.


Assuntos
Infecções por Actinomycetales , Neoplasias Cutâneas , Doença de Whipple , China , Humanos , Masculino , Tropheryma , Doença de Whipple/diagnóstico , Doença de Whipple/tratamento farmacológico
8.
Vet Microbiol ; 267: 109373, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35217354

RESUMO

Tracheal washing fluid was collected from 170 foals at 28 and 35 d old from February to July in a foaling season on horse-breeding farms with sporadic rhodococcosis in Japan and was investigated by quantitative culture. The history of the 170 foals followed up for the next few months. The proportion of R. equi-positive foals at 28 and 35 d old was significantly increased according to the birth month. Furthermore, the mean number of R. equi in the tracheal washing fluid of each month group increased according to their birth month with the rise in outside temperature. During the follow-up observation, 9/30 foals (30.0 %) born in February showed the first clinical signs at 56 ± 8 d old, 21/61 foals (34.4 %) born in March showed the signs at 37 ± 3 d old, 15/49 foals (30.6 %) born in April showed the signs at 39 ± 2 d old, and 7/30 foals (23.3 %) born in May showed signs at 44 ± 3 d old. Two sick foals (6.7 %) born in February, 19 sick foals (31.1 %) born in March, 15 sick foals (30.6 %) born in April, and 6 sick foals (20.0 %) born in May showed a positive culture of R. equi at 28 or 35 d old. The present study revealed that birth month is associated with the initial colonization of R. equi in the trachea of newborn foals on farms with sporadic rhodococcosis in Japan. Therefore, birth month might be a risk factor for developing R. equi pneumonia in foals.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Rhodococcus equi , Infecções por Actinomycetales/veterinária , Animais , Animais Recém-Nascidos , Fazendas , Doenças dos Cavalos/epidemiologia , Cavalos , Japão/epidemiologia , Traqueia
9.
BMC Res Notes ; 15(1): 50, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35164828

RESUMO

OBJECTIVE: The efficacy of Rhodococcus equi-specific hyperimmune plasma (HIP) is usually evaluated in vitro. Anticoagulants (AC) used for plasma collection can negatively impact bacterial replication but their effect on R. equi growth has not been evaluated. The aim of this study was to establish the effect that AC routinely used in veterinary medicine (ACD, K2EDTA, Li Heparin, and Na Citrate) have on in vitro R. equi growth. To assess this, in vitro assays commonly used to test HIP efficacy (direct effect on microorganism and macrophage infection), were performed using each AC and non-treated bacteria. RESULTS: There was no direct effect of ACD, Li Heparin or Na Citrate on R. equi growth. These AC significantly (p < 0.05) delayed growth for 12 h following opsonization. The number of R. equi colonies after macrophage infection was significantly (p < 0.05) lower 72 h post-opsonization with Na Citrate. K2EDTA inhibited the formation of R. equi colonies by 12 h in all the assays. In conclusion, AC should be taken into consideration when interpreting in vitro results as their negative effect on bacterial growth may be mistakenly interpreted as HIP efficacy. ACD and Li Heparin appear more appropriate for the selected assays.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Rhodococcus equi , Animais , Anticorpos Antibacterianos , Anticoagulantes/farmacologia , Cavalos
10.
Microb Pathog ; 164: 105435, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35121072

RESUMO

Trueperella pyogenes is an opportunistic bacterial pathogen causing several infectious diseases, including metritis, mastitis and abscesses in domestic animals such as dairy cattle. Several virulence proteins are released by T. pyogenes strains contributing to the pathogenic and causing disease potential of this pathogen. So far, many aspects of T. pyogenes pathogenesis are unknown. In this study, expression levels of plo, fimA, nanH and cbpA genes encoding pyolysin, fimbriae, neuraminidase and collagen-binding protein, respectively in T. pyogenes isolated from totally 15 metritis, mastitis and cutaneous abscesses convenience samples in response to co-culture with other pathogens including E. coli, St. dysgalactiae, S. aureus, F. necrophorum and L. plantarum strains in mice study model have been investigated. We found that expression levels of plo, fimA, nanH and cbpA genes in T. pyogenes isolates in response to co-culture with F. necrophorum and E. coli were significantly increased; however, no significant changes was seen in the level of expression of these genes in the isolates in response to co-culture with St. dysgalactiae and S. aureus. Notably, expression of all virulence factor genes was suppressed in T. pyogenes in response to co-culture with L. plantarum. We observed that L. plantarum might be used to prevent infectious diseases caused by T. pyogenes.


Assuntos
Actinomycetaceae , Infecções por Actinomycetales , Coinfecção , Actinomycetaceae/genética , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/veterinária , Animais , Bovinos , Escherichia coli/genética , Feminino , Camundongos , Staphylococcus aureus , Fatores de Virulência/genética
11.
Lett Appl Microbiol ; 74(1): 27-31, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34608644

RESUMO

Rhodococcus equi was isolated from the gastrointestinal contents of earthworms (family Megascolecidae) and their surrounding soil collected from pastures of two horse-breeding farms in Aomori Prefecture, outdoor pig pens, forest in Towada campus, orange groves and forest where wild boars (Sus scrofa) are established in Tanabe, Wakayama Prefecture. The number of R. equi in the lower gastrointestinal contents of 23 earthworms collected from our campus was significantly larger than that of the upper gastrointestinal content. The mean numbers of R. equi from the gastrointestinal contents of earthworms collected from the various places were 2·3-fold to 39·7-fold more than those of the surrounding soil samples. In all, 1771 isolates from the earthworms and 489 isolates from the soil samples were tested for the presence of vapA and vapB genes using polymerase chain reaction. At the horse-breeding farm N, 9 of the 109 isolates (8·3%) from the earthworms and 7 of the 106 isolates (6·6%) from the soil samples were positive for the vapA gene. At the University's forest, one of the 250 isolates (0·4%) from the gastrointestinal contents of the earthworm was positive for the vapB gene. These results revealed that R. equi can be found in significant quantities in the gastrointestinal contents of earthworms, suggesting that they act as an accumulator of R. equi in the soil environment and as a source or reservoir of animal infection.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Oligoquetos , Rhodococcus equi , Animais , Conteúdo Gastrointestinal , Cavalos , Microbiologia do Solo
12.
Equine Vet J ; 54(1): 121-131, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33445210

RESUMO

BACKGROUND: Many foals that develop thoracic ultrasonographic lesions as a result of Rhodococcus equi infection heal on their own. However, most of these foals receive antimicrobials because foals at risk of developing clinical pneumonia cannot be identified. Untargeted lipidomics is useful to identify candidate biomarkers. OBJECTIVES: (a) To describe the changes that occur in foal lipidomics as a result of ageing (birth to 8 weeks) and (b) To compare these results with those observed in foals after experimental infection with R. equi. STUDY DESIGN: Experimental study. METHODS: Healthy newborn foals (n = 9) were challenged with R. equi intratracheally the first week of life. Foals were treated with antimicrobials if they developed clinical pneumonia (n = 4, "clinical group") or were closely monitored if they showed no signs of disease (n = 5 "subclinical group"). An unchallenged group (n = 4) was also included. All foals were free of disease (transtracheal wash fluid evaluation and culture as well as thoracic ultrasonography) by 8 weeks of life. Plasma lipidomics was determined by LC-MS weekly for the study duration (8 weeks). RESULTS: Both ageing and experimental infection altered the foal's plasma lipidome as demonstrated by multivariate statistical analysis. The intensities of 31 lipids were altered by ageing and 12 by infection (P < .05). Furthermore, nine lipids changed by more than twofold between clinical and subclinical groups. MAIN LIMITATIONS: The number of foals is limited. Foals were experimentally challenged with R. equi. CONCLUSIONS: Ageing and R. equi infection induced changes in the plasma lipidome of foals. These experimental results provide the background for future work in the discovery of earlier biomarkers of R. equi pneumonia. Early identification of foals at risk of developing clinical pneumonia is key in order to decrease antimicrobial use and development of antimicrobial resistance.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Rhodococcus equi , Infecções por Actinomycetales/tratamento farmacológico , Infecções por Actinomycetales/veterinária , Animais , Antibacterianos , Cavalos , Lipidômica
14.
J Vet Intern Med ; 35(6): 2912-2919, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34738651

RESUMO

BACKGROUND: Hyperimmune plasma raised against ß-1→6-poly-N-acetyl glucosamine (PNAG HIP) mediates more opsonophagocytic killing of Rhodococcus equi (R equi) than does R equi hyperimmune plasma (RE HIP) in vitro. The relative efficacy of PNAG HIP and RE HIP to protect foals against R equi pneumonia, however, has not been evaluated. HYPOTHESIS: Transfusion with PNAG HIP will be superior to RE HIP in foals for protection against R equi pneumonia in a randomized, controlled, blinded clinical trial. ANIMALS: Four hundred sixty Quarter Horse and Thoroughbred foals at 5 large breeding farms in the United States. METHODS: A randomized, controlled, blinded clinical trial was conducted in which foals were transfused within 24 hours after birth with 2 L of either RE HIP or PNAG HIP. Study foals were monitored through weaning for clinical signs of pneumonia by farm veterinarians. The primary outcome was the proportion of foals that developed pneumonia after receiving each type of plasma. RESULTS: The proportion of foals that developed pneumonia was the same between foals transfused with RE HIP (14%; 32/228) and PNAG HIP (14%; 30/215). CONCLUSIONS AND CLINICAL IMPORTANCE: Results indicate that PNAG HIP was not superior to a commercially available, United States Department of Agriculture-licensed RE HIP product for protecting foals against R equi pneumonia under field conditions.


Assuntos
Infecções por Actinomycetales , Doenças dos Cavalos , Pneumonia Bacteriana , Rhodococcus equi , Acetilglucosamina , Infecções por Actinomycetales/prevenção & controle , Infecções por Actinomycetales/veterinária , Animais , Anticorpos Antibacterianos , Doenças dos Cavalos/prevenção & controle , Cavalos , Pneumonia Bacteriana/prevenção & controle , Pneumonia Bacteriana/veterinária
15.
PLoS Pathog ; 17(9): e1009888, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34473814

RESUMO

Rhodococcus equi is a major cause of foal pneumonia and an opportunistic pathogen in immunocompromised humans. While alveolar macrophages constitute the primary replicative niche for R. equi, little is known about how intracellular R. equi is sensed by macrophages. Here, we discovered that in addition to previously characterized pro-inflammatory cytokines (e.g., Tnfa, Il6, Il1b), macrophages infected with R. equi induce a robust type I IFN response, including Ifnb and interferon-stimulated genes (ISGs), similar to the evolutionarily related pathogen, Mycobacterium tuberculosis. Follow up studies using a combination of mammalian and bacterial genetics demonstrated that induction of this type I IFN expression program is largely dependent on the cGAS/STING/TBK1 axis of the cytosolic DNA sensing pathway, suggesting that R. equi perturbs the phagosomal membrane and causes DNA release into the cytosol following phagocytosis. Consistent with this, we found that a population of ~12% of R. equi phagosomes recruits the galectin-3,-8 and -9 danger receptors. Interestingly, neither phagosomal damage nor induction of type I IFN require the R. equi's virulence-associated plasmid. Importantly, R. equi infection of both mice and foals stimulates ISG expression, in organs (mice) and circulating monocytes (foals). By demonstrating that R. equi activates cytosolic DNA sensing in macrophages and elicits type I IFN responses in animal models, our work provides novel insights into how R. equi engages the innate immune system and furthers our understanding how this zoonotic pathogen causes inflammation and disease.


Assuntos
Infecções por Actinomycetales/imunologia , Imunidade Inata/imunologia , Interferon Tipo I/imunologia , Macrófagos/imunologia , Rhodococcus equi/imunologia , Animais , Citosol/imunologia , DNA/imunologia , Feminino , Doenças dos Cavalos/imunologia , Cavalos , Masculino , Camundongos
16.
Microb Pathog ; 160: 105186, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34509529

RESUMO

Rhodococcus equi is a well-known intracellular facultative bacterium that is opportunistic in nature, and a contagious disease-causing agent of pyogranulomatous infections in humans and multihost animals. Feline rhodococcosis is an uncommon or unnoticed clinical condition, in which the organism is usually refractory to conventional antimicrobial therapy. The pathogenicity of the agent is intimately associated with plasmid-governed infectivity, which is attributed to the presence of plasmid-encoded virulence-associated proteins (Vap). Three host-adapted virulence plasmid types (VAPs) have been distinguished to date: pVAPA, pVAPB, and pVAPN, whose infections are related to equine, pig, and bovine or caprine origin, respectively, while humans are infected by all three VAP types. Most virulence studies with R. equi plasmid types in animals involve livestock species. Conversely, data on the pathogenicity and human relevance of the virulence plasmid profile of R. equi isolated from cats remains unclear. This report describes a case of cellulitis-related R. equi that harbors the pVAPA-type in a cat with cutaneous lesion. Long-term therapy of the cat using marbofloxacin, a broad-spectrum third-generation fluoroquinolone, resulted effectiveness. pVAPA is a host-adapted virulent type that has been associated predominantly with pulmonary foal infections. Our cat had a history of contact with other cats, livestock (including horses), and farm environment that could have favored the transmission of the pathogen. Besides no clear evidence of cat-to-humans transmission of the pathogen, the identification of R. equi harboring pVAPA-type in a cat with cutaneous abscessed lesion represent relevance in human health because this virulent type has been described in people worldwide with clinical rhodococcal disorders.


Assuntos
Infecções por Actinomycetales , Celulite (Flegmão) , Rhodococcus equi , Infecções por Actinomycetales/veterinária , Animais , Proteínas de Bactérias/genética , Gatos , Celulite (Flegmão)/microbiologia , Celulite (Flegmão)/veterinária , Plasmídeos/genética , Rhodococcus equi/genética , Fatores de Virulência/genética
17.
PLoS One ; 16(8): e0250133, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34437551

RESUMO

The efficacy of transfusion with hyperimmune plasma (HIP) for preventing pneumonia caused by Rhodococcus equi remains ill-defined. Quarter Horse foals at 2 large breeding farms were randomly assigned to be transfused with 2 L of HIP from adult donors hyperimmunized either with R. equi (RE HIP) or a conjugate vaccine eliciting antibody to the surface polysaccharide ß-1→6-poly-N-acetyl glucosamine (PNAG HIP) within 24 hours of birth. Antibody activities against PNAG and the rhodococcal virulence-associated protein A (VapA), and to deposition of complement component 1q (C՛1q) onto PNAG were determined by ELISA, and then associated with either clinical pneumonia at Farm A (n = 119) or subclinical pneumonia at Farm B (n = 114). Data were analyzed using multivariable logistic regression. Among RE HIP-transfused foals, the odds of pneumonia were approximately 6-fold higher (P = 0.0005) among foals with VapA antibody activity ≤ the population median. Among PNAG HIP-transfused foals, the odds of pneumonia were approximately 3-fold (P = 0.0347) and 11-fold (P = 0.0034) higher for foals with antibody activities ≤ the population median for PNAG or C՛1q deposition, respectively. Results indicated that levels of activity of antibodies against R. equi antigens are correlates of protection against both subclinical and clinical R. equi pneumonia in field settings. Among PNAG HIP-transfused foals, activity of antibodies with C՛1q deposition (an indicator of functional antibodies) were a stronger predictor of protection than was PNAG antibody activity alone. Collectively, these findings suggest that the amount and activity of antibodies in HIP (i.e., plasma volume and/or antibody activity) is positively associated with protection against R. equi pneumonia in foals.


Assuntos
Acetilglucosamina/imunologia , Infecções por Actinomycetales/veterinária , Anticorpos Antibacterianos/uso terapêutico , Proteínas de Bactérias/imunologia , Doenças dos Cavalos/prevenção & controle , Imunização Passiva/veterinária , Pneumonia Bacteriana/veterinária , Rhodococcus equi/imunologia , Infecções por Actinomycetales/imunologia , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/prevenção & controle , Animais , Animais Recém-Nascidos/imunologia , Animais Recém-Nascidos/microbiologia , Anticorpos Antibacterianos/imunologia , Feminino , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/microbiologia , Cavalos/imunologia , Cavalos/microbiologia , Imunização Passiva/métodos , Masculino , Pneumonia Bacteriana/imunologia , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/prevenção & controle
18.
Avian Dis ; 65(1): 171-176, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-34339137

RESUMO

Trueperella pyogenes is an opportunistic Gram-positive bacterium that induces purulent lesions and abscesses in cattle, small ruminants, and swine. In birds, T. pyogenes infections have been linked to lameness and osteomyelitis in turkeys (Phasianidae) and hepatic fibriscess in turkeys and pigeons (Columbidae). An 18-mo-old backyard rooster with a history of progressive emaciation was submitted to the California Animal Health and Food Safety (CAHFS) laboratory system. At necropsy, unusual numerous miliary granulomas were identified, primarily in the spleen, but granulomas were also observed in air sacs and lungs. Microscopically, few to moderate numbers of granulomas with giant cells were observed in the spleen, lung, air sacs, and crop composed of necrosis and mixed inflammatory cell inflammation including multinucleated giant cells, fibrin deposition, and fibrosis. Trueperella pyogenes was isolated from the air sacs and trachea. Avibacterium paragallinarum PCR was positive from the tracheal swab. A retrospective analysis of CAHFS data on T. pyogenes between 2000 and 2020 identified 24 cases in avian species: chickens (Gallus gallus domesticus; 16/24), turkeys (5/24), Pekin duck (Anas platyrhynchos domesticus; 1/24), parrot (Psittaciformes; 1/24), and pheasant (Phasianidae; 1/24). Although T. pyogenes infection in birds is rare, the clinical signs and gross lesions might be indistinguishable from avian mycobacteriosis in some cases and should be considered in the differential diagnosis.


Reporte de caso­Un caso no común de infección por Trueperella pyogenes en un gallo adulto de traspatio y un estudio retrospectivo; entre los años 2000-20. Trueperella pyogenes es una bacteria grampositiva oportunista que induce lesiones purulentas y abscesos en bovinos, pequeños rumiantes y porcinos. En las aves, las infecciones por T. pyogenes se han relacionado con cojera y osteomielitis en pavos (Phasianidae) y fibrosis hepática en pavos y palomas (Columbidae). Un gallo de traspatio de 18 meses de edad con antecedentes de emaciación progresiva fue enviado al sistema de Laboratorios de Salud Animal y Seguridad Alimentaria de California (CAHFS). En la necropsia, se identificaron numerosos granulomas miliares inusuales, principalmente en el bazo, pero también se observaron granulomas en los sacos aéreos y los pulmones. Microscópicamente, se observaron pocos a moderados granulomas con células gigantes en el bazo, pulmón, sacos aéreos y buche compuesto por necrosis e inflamación celular inflamatoria mixta, incluidas células gigantes multinucleadas, depósito de fibrina y fibrosis. Trueperella pyogenes se aisló de los sacos aéreos y la tráquea. Un método de PCR para Avibacterium paragallinarum fue positivo realizado a partir de hisopos traqueales. Un análisis retrospectivo de los datos de CAHFS sobre T. pyogenes entre los años 2000 y 2020 identificó 24 casos en especies aviares: pollos (Gallus gallus domesticus; 16/24), pavos (5/24), pato Pekín (Anas platyrhynchos domesticus; 1/24), loro (Psittaciformes; 1/24) y faisán (Phasianidae; 1/24). Aunque la infección por T. pyogenes en aves es poco común, los signos clínicos y las lesiones macroscópicas pueden ser indistinguibles de micobacteriosis aviar en algunos casos y debe considerarse como diagnóstico diferencial.


Assuntos
Actinomycetaceae/isolamento & purificação , Infecções por Actinomycetales/veterinária , Galinhas , Doenças das Aves Domésticas/diagnóstico , Actinomycetaceae/fisiologia , Infecções por Actinomycetales/diagnóstico , Infecções por Actinomycetales/microbiologia , Animais , California , Patos , Galliformes , Masculino , Doenças das Aves Domésticas/microbiologia , Psittaciformes , Estudos Retrospectivos , Perus
19.
Int J Med Microbiol ; 311(6): 151519, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34280738

RESUMO

Rhodococcus equi is a saprophytic soil bacterium and intracellular pathogen that causes refractory suppurative pneumonia in foals and has emerged as a pathogenic cause of zoonotic disease. Several studies have reported human infections caused by R. equi harboring a recently described third type of virulence plasmid, the ruminant-associated pVAPN, which carries the vapN virulence determinant. Herein, we analyzed pathogenicity and genomic features of nine vapN-harboring R. equi isolated from human patients with and without HIV/AIDS. Four of these strains showed significant VapN production and proliferation in cultured macrophages. These strains were lethally pathogenic after inoculation with 1.0 × 108 CFU in mice and reproduced a necrotizing granulomatous inflammation in the liver and spleen similar to that observed in humans. Additionally, we determined entire genome sequences of all nine strains. Lengths of sequences were 5.0-5.3 Mbp, and GC contents were 68.7 %-68.8 %. All strains harbored a 120- or 125-kbp linear plasmid carrying vapN (Type I or Type II pVAPN) classified on the basis of differences in the distal sequences on the 3' side. Interestingly, VapN production differed significantly among strains harboring nearly identical types of pVAPN with variation limited to several SNPs and short base pair indels. The pVAPN sequences possessed by the VapN-producing strains did not retain any common genetic characteristics, and more detailed analyses, including chromosomal genes, are needed to further elucidate the VapN expression mechanism.


Assuntos
Infecções por Actinomycetales , Rhodococcus equi , Rhodococcus , Infecções por Actinomycetales/veterinária , Animais , Genômica , Cavalos , Humanos , Camundongos , Plasmídeos/genética , Rhodococcus equi/genética , Virulência
20.
Microbiol Spectr ; 9(1): e0063821, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34319137

RESUMO

Rhodococcus equi is a prevalent cause of pneumonia in foals worldwide. Our laboratory has demonstrated that vaccination against the surface polysaccharide ß-1→6-poly-N-acetylglucosamine (PNAG) protects foals against intrabronchial infection with R. equi when challenged at age 28 days. However, it is important that the efficacy of this vaccine be evaluated in foals when they are infected at an earlier age, because foals are naturally exposed to virulent R. equi in their environment from birth and because susceptibility is inversely related to age in foals. Using a randomized, blind experimental design, we evaluated whether maternal vaccination against PNAG protected foals against intrabronchial infection with R. equi 6 days after birth. Vaccination of mares per se did not significantly reduce the incidence of pneumonia in foals; however, activities of antibody against PNAG or for deposition of complement component 1q onto PNAG was significantly (P < 0.05) higher among foals that did not develop pneumonia than among foals that developed pneumonia. Results differed between years, with evidence of protection during 2018 but not 2020. In the absence of a licensed vaccine, further evaluation of the PNAG vaccine is warranted, including efforts to optimize the formulation and dose of this vaccine. IMPORTANCE Pneumonia caused by R. equi is an important cause of disease and death in foals worldwide for which a licensed vaccine is lacking. Foals are exposed to R. equi in their environment from birth, and they appear to be infected soon after parturition at an age when innate and adaptive immune responses are diminished. Results of this study indicate that higher activity of antibodies recognizing PNAG was associated with protection against R. equi pneumonia, indicating the need for further optimization of maternal vaccination against PNAG to protect foals against R. equi pneumonia.


Assuntos
Acetilglucosamina/administração & dosagem , Infecções por Actinomycetales/veterinária , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/administração & dosagem , Doenças dos Cavalos/prevenção & controle , Pneumonia/veterinária , Rhodococcus equi/fisiologia , Acetilglucosamina/imunologia , Infecções por Actinomycetales/sangue , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/prevenção & controle , Animais , Animais Recém-Nascidos/sangue , Animais Recém-Nascidos/imunologia , Animais Recém-Nascidos/microbiologia , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/imunologia , Feminino , Doenças dos Cavalos/sangue , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/microbiologia , Cavalos , Masculino , Pneumonia/sangue , Pneumonia/microbiologia , Pneumonia/prevenção & controle , Rhodococcus equi/genética , Vacinação
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