Diversity and dynamics of bacteria at the Chrysomya megacephala pupal stage revealed by third-generation sequencing.

Characterization of the microbial community is essential for understanding the symbiotic relationships between microbes and host insects. Chrysomya megacephala is a vital resource, a forensic insect, a pollinator, and a vector for enteric bacteria, protozoa, helminths, and viruses. However, research on its microbial community is incomprehensive, particularly at the pupal stage, which comprises approximately half of the entire larval development stage and is important entomological evidence in forensic medicine. For the first time, this study investigated the bacterial communities of C. megacephala pupae at different ages using third-generation sequencing technology. The results showed that C. megacephala has a diverse and dynamic bacterial community. Cluster analysis at ≥ 97% similarity produced 154 operational taxonomic units (OTUs) that belonged to 10 different phyla and were distributed into 15 classes, 28 orders, 50 families, 88 genera, and 130 species. Overall, the number of bacterial OTUs increased with the development of pupae, and the relative abundance of Wolbachia in the Day5 group was significantly lower than that in the other groups. Within the pupal stage, Proteobacteria, Firmicutes, and Bacteroidetes were the dominant phyla of bacteria. At the genus level, Wolbachia and Ignatzschineria coexisted, a rarely known feature. In addition, we found Erysipelothrix rhusiopathiae, the etiological agent of swine erysipelas, which is rarely identified in insects. This study enriches the understanding of the microbial community of C. megacephala and provides a reference for better utilization and control of C. megacephala.

Quantification of IgY to Erysipelothrix rhusiopathiae in serum from Swedish laying hens.

BACKGROUND: Erysipelas, caused by Erysipelothrix rhusiopathiae (ER), is an important emerging disease in free-range and organic egg-production. The aim of the present study was to assess if quantification of ER specific IgY titers may aid the understanding of erysipelas in commercial laying hens. The methodology was validated with sequentially collected sera from experimentally ER infected SPF-chickens and subsequently applied on sera from Swedish commercial laying hens collected during and after outbreaks of erysipelas or collected at slaughter from healthy hens housed in furnished cages, barn production or in organic production (with outdoor access). RESULTS: In experimentally infected SPF-chickens, titers to ER were significantly increased approximately one week after infection while IgY to ER in uninfected age-matched controls remained low. Also chickens infected with low doses of ER, not displaying clinical signs of disease and with low recovery of ER in blood samples showed high titers of IgY to ER. For laying hens during and after erysipelas outbreaks the majority of samples were considered positive for antibodies to ER with a large variation in levels of IgY titers to ER between individuals. For healthy laying hens at slaughter all samples were deemed positive for antibodies to ER. An influence of flock on levels of IgY titers to ER was observed for both healthy hens and hens during erysipelas outbreaks. For healthy laying hens at slaughter no influence of the housing systems included in the study, history of erysipelas outbreaks at the farm or vaccination on levels of IgY titers to ER was noticed. CONCLUSIONS: Taken together, these results show that high numbers of commercial laying hens showed high IgY titers to ER, comparable to those elicited by experimental ER infection, indicating that ER or bacteria that raises antibodies that cross-react with ER are common in this environment.

Comparative genomics of a novel clade shed light on the evolution of the genus Erysipelothrix and characterise an emerging species.

Erysipelothrix sp. isolates obtained from a deadly outbreak in farmed turkeys were sequenced and compared to representatives of the genus. Phylogenetic trees-supported by digital DNA:DNA hybridization and Average Nucleotide Identity-revealed a novel monophyletic clade comprising isolates from pigs, turkeys, and fish, including isolates previously described as E. sp. Strain 2. Genes coding for the SpaC protein, typically found in E. sp. Strain 2, were detected in all isolates of the clade. Therefore, we confirm E. sp. Strain 2 represents a unique species that may be isolated from a broad host range, and the name "Erysipelothrix takahashiae" is suggested. Core genome analysis showed that the pathogenic species of this genus, E. rhusiopathiae and the clade E. sp. Strain 2, are enriched in core functionalities related to nutrient uptake and transport, but not necessarily homologous pathways. For instance, whereas the aerobic DctA transporter may uptake C4-dicarboxylates in both species, the anaerobic DcuC transporter is exclusive of the E. sp. Strain 2. Remarkably, the pan-genome analysis uncovered that genes related to transport and metabolism, recombination and repair, translation and transcription in the fish isolate, within the novel clade, have undergone a genomic reduction through pseudogenization. This reflects distinct selective pressures shaping the genome of species and strains within the genus Erysipelothrix while adapting to their respective niches.

Erysipelothrix rhusiopathiae Endocarditis in a Patient With Severe Unicuspid Aortic Valve Damage Complicated With Acquired Ventricular Septal Defect.

Erysipelothrix rhusiopathiae, is an important animal pathogen, but rarely reported in humans. To date, only fa ew cases of infective E rhusiopathiae endocarditis of the aortic valve have been described. We introduce the first reported case of severe damage of the native unicuspid aortic valve complicated with acquired ventricular septal defect caused by E rhusiopathiae endocarditis. This case may provide a better understanding of the disease process and transmission and underscores the need to include this pathogen in the differential diagnosis of infective endocarditis.

Infective endocarditis due to Erysipelothrix rhusiopathiae in a dog - a case report.

BACKGROUND: Infective endocarditis is a rare but severe condition associated with a high mortality rate in small animal patients. This condition is caused by a microbial (most often bacterial) infection of the valvular portion of the endocardium, from which proliferative and/or erosive lesions on the cardiac valves or immediately adjacent structures develop. The two most commonly affected cardiac valves are the aortic and mitral valves. CASE PRESENTATION: We report the clinical case of a 4-year old male neutered Bull terrier, 27.6 kg, body condition score 4/9, that presented with a 3-months history of pyrexia and general weakness. The patient history also revealed a transient left hind limb lameness (grade 2/4), which coincided with the onset of clinical signs about 3 months before presentation. On physical examination, a left-sided systolic heart murmur (grade 3/6) with the same intensity at the left heart base and apex, and an irregularly irregular heart rhythm were noted. Electrocardiography showed ventricular premature complexes, and echocardiography revealed lesions consistent with endocarditis involving the aortic and mitral valve. Bacterial culture of blood yielded a positive result, and the organism isolated was identified as Erysipelothrix rhusiopathiae. The extended patient history revealed that the dog lived close to a farm housing pigs and other livestock. CONCLUSION: We report a rare case of the premortal diagnosis of infective bacterial endocarditis in a dog due to E. rhusiopathiae infection. Most reports about this condition are from necropsy series. This clinical case report emphasizes that E. rhusiopathiae infection and bacteremia should be considered as a differential diagnosis in dogs with suspected infective endocarditis, especially in dogs living in rural areas with access to livestock and particularly farm pigs. Also, particular emphasis should be placed on the zoonotic potential of this infectious disease.

Celulitis recurrente importada, la importancia de la anamnesis / Imported recurrent cellulitis, the relevance of anamnesis

No disponible

Novel insights into serodiagnosis and epidemiology of Erysipelothrix rhusiopathiae, a newly recognized pathogen in muskoxen (Ovibos moschatus).

BACKGROUND: Muskoxen are a key species of Arctic ecosystems and are important for food security and socio-economic well-being of many Indigenous communities in the Arctic and Subarctic. Between 2009 and 2014, the bacterium Erysipelothrix rhusiopathiae was isolated for the first time in this species in association with multiple mortality events in Canada and Alaska, raising questions regarding the spatiotemporal occurrence of the pathogen and its potential impact on muskox populations. MATERIALS AND METHODS: We adapted a commercial porcine E. rhusiopathiae enzyme-linked immunosorbent assay to test 958 blood samples that were collected from muskoxen from seven regions in Alaska and the Canadian Arctic between 1976 and 2017. The cut-off between negative and positive results was established using mixture-distribution analysis, a data-driven approach. Based on 818 samples for which a serological status could be determined and with complete information, we calculated trends in sample seroprevalences in population time-series and compared them with population trends in the investigated regions. RESULTS: Overall, 219/818 (27.8%, 95% Confidence Interval: 24.7-31.0) samples were classified as positive for exposure to E. rhusiopathiae. There were large variations between years and regions. Seropositive animals were found among the earliest serum samples tested; 1976 in Alaska and 1991 in Canada. In Alaskan muskoxen, sample seroprevalence increased after 2000 and, in two regions, peak seroprevalences occurred simultaneously with population declines. In one of these regions, concurrent unusual mortalities were observed and E. rhusiopathiae was isolated from muskox carcasses. In Canada, there was an increase in sample seroprevalence in two muskox populations following known mortality events that had been attributed to E. rhusiopathiae. CONCLUSION: Our results indicate widespread exposure of muskoxen to E. rhusiopathiae in western Canada and Alaska. Although not new to the Arctic, we documented an increased exposure to the pathogen in several regions concurrent with population declines. Understanding causes for the apparent increased occurrence of this pathogen and its association with large scale mortality events for muskoxen is critical to evaluate the implications for wildlife and wildlife-dependent human populations in the Arctic.

Retrospective Summary of Erysipelothrix rhusiopathiae Diagnosed in Avian Species in California (2000-19).

Erysipelas is a bacterial disease caused by Erysipelothrix rhusiopathiae that affects multiple mammalian and avian species. In poultry, the disease is of sporadic prevalence and more often observed in older birds, leading to decreased egg production and mortality. Among avian species, turkey breeders seem to be the most affected, but outbreaks have been reported in ducks, layer chickens, quails, geese, and various captive and free-range birds. Sixty-seven cases of erysipelas have been diagnosed in animals submitted for necropsy evaluation at the California Animal Health and Food Safety Laboratory System from January 2000 to December 2019. Of these, 38 cases (56.72%) were in avian species, and a retrospective analysis of these avian cases was performed. The majority of the avian cases were in turkeys (17/38, 44.74%). Most of the turkey breeder cases reported performing artificial insemination prior to the increase in mortality. In other birds, mortality was often observed without observing previous clinical signs. The majority of cases presented with coinfections with other pathogens (23/38, 60.53%), which might have affected the clinical outcome. Despite the occasional occurrence in avian species, erysipelas is an important pathogen in poultry and should be considered as a differential diagnosis in other avian species when acute septicemia is suspected as the cause of mortality.

Description of Erysipelothrix piscisicarius sp. nov., an emergent fish pathogen, and assessment of virulence using a tiger barb (Puntigrus tetrazona) infection model.

A recently described emergent disease of ornamental fish has been associated with an Erysipelothrix species positive for the surface protective antigen (spa) C gene. Whole genome sequencing was performed on five spaC Erysipelothrix isolates from diseased ornamental fish. In addition, these spaC Erysipelothrix isolates were compared to spaA-, spaB- and other spaC-positive Erysipelothrix species isolated from terrestrial and marine mammals, birds and fish using multi-locus sequence analysis (MLSA). The genomes of fish pathogenic spaC isolates were genetically distinct from Erysipelothrix rhusiopathiae, sharing 86.61-86.94 % average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of 31.6-32.2 %, but 99.01-99.11 % ANI and 90.8-91.9 % dDDH values with the uncharacterized spaC-positive Erysipelothrix sp. strain 2 isolated from swine. The findings indicate the spaC-positive fish and swine isolates are conspecific and represent a previously unrecognized taxon. While phylogenies inferred from MLSA sequences confirm this conclusion, slight genetic differences between the spaC fish isolates and swine strain 2 were indicated. Bath immersion challenge trials were conducted using tiger barbs (Puntigrus tetrazona) exposed by immersion to 107 c.f.u. ml-1 of three fish pathogenic spaC Erysipelothrix species, and three spaA and two spaB E. rhusiopathiae isolates as a model of infection. Thirty days post-challenge, cumulative mean percentage survival was 37 % for the spaA, 100 % for the spaB and 13 % for the spaC isolates, revealing differences in virulence among the various spa genotypes in fish. Genetic findings and observed differences in virulence demonstrate the fish pathogenic spaC isolates represent a novel species, for which the name Erysipelothrix piscisicarius sp. nov. is proposed. The type strain is E. piscisicarius 15TAL0474T (=NRRL B-65533T=ATCC-TSD-175T=DSM 110099T).

Native valve endocarditis caused by E rysipelothrix Rh usiopathiae: presenting with refractory heart failure and requiring surgical valve replacement-report on a rare zoonosis.

Erysipelothrix Rhusiopathiae is a Gram-positive bacillus that is ubiquitous in nature. The bacterium is a zoonotic pathogen known to infect wild and domestic animals. Human infections, however, are uncommon and typically present with localised or generalised cutaneous lesions. Systemic infection in the form of bacteraemia with seeding to various organs is the least common form of the disease. Infections in humans tend to be associated with occupational exposure and close contact with animals. Clinical data of a 61-year-old male patient with Gram-positive bacilli bacteraemia and E. Rh usiopathiae-induced endocarditis are presented here. The patient presented with refractory congestive heart failure secondary to severe acute aortic regurgitation mandating surgical valve replacement. The described case has special clinical merit given the lack of fever and leukocytosis, absence of erysipeloid cutaneous manifestations and refractoriness to medical management. E. Rhusiopathiae should be considered in the differential diagnosis for Gram-positive bacilli bacteraemia and endocarditis. In the proper clinical setting, occupational exposure and animal contacts are helpful clues to raise suspicion for this bacillus. The high mortality associated with the pathogen should urge for early identification and initiation of antimicrobial treatment.

Erysipelothrix Septicaemia and Hepatitis in a Colony of Humboldt Penguins (Spheniscus humboldti).

This report describes an outbreak of erysipelas in a colony of captive Humboldt penguins (Spheniscus humboldti). The only previously reported case in a related species was of an individual little blue penguin (Eudyptula minor). Five Humboldt penguins in a mixed colony displayed non-specific signs of illness, including lethargy, inappetence and regurgitation after movement for exhibit upgrading. There was no improvement after 5 days of treatment with oral enrofloxacin (10 mg/kg q24h). Four Humboldt penguins, including two that were not part of the original five displaying signs of illness, died during this outbreak and Erysipelothrix rhusiopathiae was cultured from organ samples collected post mortem. Oral clavulanic acid/amoxycillin (125 mg/kg q12h) was added to the treatment of the sick Humboldt penguins, as well as itraconazole (8.5 mg/kg q12h) and silymarin (10 mg/kg q24h) for 10 days (both per os), which resolved their clinical signs. The likely source of E. rhusiopathiae was the fish they were fed, but this could not be confirmed. Another contributing factor to the growth of E. rhusiopathiae in the exhibit pool was the increase in water temperature due to a fault in the water circulating system. The temperature of the pool water had increased to 29°C, which was rectified, and the water temperature decreased to 13°C. However, there was one further Humboldt penguin death after the decrease in water temperature. This episode suggests that E. rhusiopathiae infection should be high on the differential list of piscivorous avian species with non-specific clinical signs. A liver biopsy for bacterial culture and sensitivity may be required for definitive diagnosis.

Wild boars: A potential source of Erysipelothrix rhusiopathiae infection in Japan.

The potential role of wild boars as a source of erysipelas infection was investigated. An ELISA test of wild boar serum samples from 41 prefectures in Japan revealed that proportions of the Erysipelothrix rhusiopathiae-positive samples were very high in all the prefectures, and the mean positive rate was 95.6% (1312/1372). Serovars of E. rhusiopathiae isolates from wild boars were similar to those of previously reported swine isolates, and all serovar isolates tested were found to be pathogenic to mice. These results suggest that wild boars in Japan constitute a reservoir of E. rhusiopathiae and may pose risks to other animals.

Erysipeloid lesions caused by Erysipelothrix rhusiopathiae in a dog: clinical and histopathological findings, molecular diagnosis and treatment.

BACKGROUND: Erysipelothrix rhusiopathiae is a widespread Gram-positive, nonsporulating rod bacterium predominantly associated with skin disease in swine and cetaceans. Cutaneous lesions have yet to be described in dogs. OBJECTIVE: To describe the clinical presentation, molecular and histopathological diagnosis, and treatment of a case of erysipeloid caused by E. rhusiopathiae in a dog. ANIMALS: A 6-month-old spayed female standard poodle dog presented with lethargy, fever, vomiting and diarrhoea. Skin lesions appeared 20 days post first examination. METHODS AND MATERIALS: Complete blood count, serum chemistry profile, urinalysis, urine culture, blood culture, computed topography, forelimb radiography, joint and cerebrospinal fluid aspiration were performed; samples were collected for skin cytological evaluation, culture and histopathological analysis. RESULTS: Blood cultures yielded Gram-positive, catalase-negative bacilli. Histopathological evaluation of skin biopsies revealed lymphoplasmacytic, neutrophilic and histiocytic perivascular and periadnexal dermatitis, and vasculitis. Cutaneous and blood PCR and sequencing of 16S rRNA identified the bacteria as E. rhusiopathiae. Clinical resolution was observed following the use of of amoxicillin/clavulanic acid and ciprofloxacin therapies. CONCLUSIONS AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first confirmed case of erysipeloid caused by E. rhusiopathiae in a dog. Clinical resolution was attained with the extended use of antibiotics. After 13 months, no clinical signs had returned.

Detection and quantification of Erysipelothrix rhusiopathiae in blood from infected chickens - addressing challenges with detection of DNA from infectious agents in host species with nucleated red blood cells.

PURPOSE: The present study aimed to establish pretreatment protocols as well as real-time and droplet digital polymerase chain reaction (PCR) methodologies to detect and quantify Erysipelothrix rhusiopathiae (ER) DNA in blood samples from infected chickens, as tools for routine diagnostics and monitoring of experimental infections. Chicken blood is a problematic matrix for PCR analysis because nucleated erythrocytes contribute large amounts of host DNA that inhibit amplification. METHODOLOGY: Using artificially spiked samples of fresh chicken blood, as well as blood samples from three experimental infection studies, the performance of pretreatment protocols, including choice of blood stabilization agent, centrifugation speeds and Ficoll gradient separation, was evaluated. The results were compared with those from traditional culture-based protocols combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).Results/Key findings. Simple preparations producing cell-free samples performed well on artificial spike-in samples, providing high sensitivity. However, performance was poor in clinical samples or artificial samples where the bacteria were incubated for 4 h or more in fresh blood prior to DNA extraction. In these samples, a Ficoll separation protocol that creates samples rich in lymphocytes, monocytes and thrombocytes prior to DNA extraction was far more effective. CONCLUSIONS: Our results indicate that ER bacteria undergo rapid phagocytosis in chicken blood and that analysis of a blood fraction enriched for phagocytic cells is necessary for reliable detection and quantification. The presented results explain the poor performance of PCR detection reported in previously published experimental ER infection studies, and the proposed solutions are likely to have broader implications for PCR-based veterinary diagnostics in non-mammalian host species such as poultry and fish.

Disassociation of Spa type and serovar of an Erysipelothrix rhusiopathiae serovar 6 strain isolated from a diseased pig.

The surface protective antigen (Spa) protein of Erysipelothrix rhusiopathiae is an important component in protecting pigs against swine erysipelas. The Spa protein has been antigenically divided into 3 types: SpaA, SpaB, and SpaC. Swine erysipelas vaccines are formulated with strains of serovar 1 and/or 2, both of which are SpaA-possessing serovars. The association of Spa type with E. rhusiopathiae serovar has been reported, and therefore, the determination of the Spa type and the serovar of clinical isolates are important to assess vaccine efficacy. An E. rhusiopathiae strain, designated Ireland, was isolated from a diseased pig and identified as serovar 6 by a conventional agar gel precipitation test. Sequence analysis of the chromosomal locus presumably defining the serovar antigenicity of E. rhusiopathiae revealed that the gene content and organization of the chromosomal regions of the Ireland strain were identical to those of the serovar 6 reference strain (Tuzok). Sequence analysis of the spa gene and dot blots using a SpaA-specific monoclonal antibody confirmed that, unlike the Tuzok strain possessing SpaB, the Ireland strain expressed SpaA, indicating that the Spa type is not associated with the serovar in this strain. Thus, further investigation into the association between Spa type and serovar of clinical swine isolates is warranted.

Identification of serovar 1a, 1b, 2, and 5 strains of Erysipelothrix rhusiopathiae by a conventional gel-based PCR.

Among the four species of the genus Erysipelothrix, Erysipelothrix rhusiopathiae is the main species that causes disease in swine and poultry and has also been isolated from human patients. Recently, E. rhusiopathiae infections in domesticated animals have increased in many countries and are also the cause of emerging wildlife disease in arctic and boreal ecosystems. Historically, E. rhusiopathiae has been differentiated from other Erysipelothrix species by their serovars, which are determined based on cell wall antigens. Serotyping of Erysipelothrix is important, as specific E. rhusiopathiae serovars (1a, 1b, and 2) are associated with disease in pigs, poultry, and humans. However, serotyping is laborious and time-consuming and requires a full set of serovar reference strains and strain-specific antiserum. In this study, to develop a conventional gel-based PCR assay that can detect the main disease-associated serovars of E. rhusiopathiae, the draft genome sequences of E. rhusiopathiae strains of serovars 1a, 1b, 2, and 5, the last of which is often isolated from wild animals, were analyzed. Primers were designed based on the serovar-specific sequences of the strains and tested for field strains isolated from extensive origins. Among two hundred and ninety-seven isolates of various serovar strains of E. rhusiopathiae and other Erysipelothrix species, the PCR assay identified serovar 1a, 1b, 2, and 5 strains of E. rhusiopathiae. This conventional gel-based PCR assay should be useful for serovar surveillance of E. rhusiopathiae isolates in domesticated and wild animals as well as in humans.

Avian cholera outbreaks threaten seabird species on Amsterdam Island.

Infectious diseases may be particularly critical for the conservation of endangered species. A striking example is the recurrent outbreaks that have been occurring in seabirds on Amsterdam Island for the past 30 years, threatening populations of three Endangered seabird species and of the endemic, Critically Endangered Amsterdam albatross Diomedea amsterdamensis. The bacteria Pasteurella multocida (avian cholera causative agent), and to a lesser extent Erysipelothrix rhusiopathiae (erysipelas causative agent), were both suspected to be responsible for these epidemics. Despite this critical situation, demographic trends were not available for these threatened populations, and the occurrence and characterization of potential causative agents of epizootics remain poorly known. The aims of the current study were to (i) provide an update of population trends for four threatened seabird species monitored on Amsterdam Island, (ii) assess the occurrence of P. multocida, and E. rhusiopathiae in live birds from five species, (iii) search for other infectious agents in these samples and, (iv) isolate and genotype the causative agent(s) of epizooties from dead birds. Our study shows that the demographic situation has worsened substantially in three seabird species during the past decade, with extremely low reproductive success and declining populations for Indian yellow-nosed albatrosses Thalassarche carteri, sooty albatrosses Phoebetria fusca, and northern rockhopper penguins Eudyptes moseleyi. Pasteurella multocida or E. rhusiopathiae were detected by PCR in live birds of all five investigated species, while results were negative for eight additional infectious agents. A single strain of P. multocida was repeatedly cultured from dead birds, while no E. rhusiopathiae could be isolated. These results highlight the significance of P. multocida in this particular eco-epidemiological system as the main agent responsible for epizootics. The study stresses the urgent need to implement mitigation measures to alter the course of avian cholera outbreaks threatening the persistence of seabird populations on Amsterdam Island.