Erysipelothrix rhusiopathiae Infection Associated with Swollen Head Syndrome in a Broiler Breeder Flock in North Georgia.

An unusual case of swollen head syndrome in a 55-wk-old broiler breeder flock was identified in north Georgia in the summer of 2019. The presenting complaint was elevated mortality and visibly swollen heads. Necropsy of affected birds on the farm primarily revealed signs of bacterial septicemia, with few large scab lesions near the vent area. Bacterial culture analysis identified multiple organisms, but the primary organism of interest was identified as Erysipelothrix rhusiopathiae, cultured from affected liver, lung, sinuses, and one swollen wattle of birds in the affected house. Histopathologic analysis identified gram-positive rod-shaped bacteria in the spleen and liver (consistent with bacterial septicemia) confirmed with special staining (Brown & Hopps Gram stain). These organisms were noted to be consistent with E. rhusiopathiae; E. rhusiopathiae infection in broiler breeder chickens is a rare occurrence and is primarily associated with turkeys and/or swine production systems.

Reporte de caso- Infección por Erysipelothrix rhusiopathiae asociada con el síndrome de cabeza hinchada en un pollo de engorde. En el verano del 2019, se identificó un caso inusual de síndrome de cabeza hinchada en una parvada de reproductoras de pollos de engorde de 55 semanas de edad en el norte de Georgia. Las observaciones iniciales incluyeron mortalidad elevada y cabezas visiblemente inflamadas. La necropsia de las aves afectadas en la granja reveló principalmente signos de septicemia bacteriana, con pocas lesiones costrosas grandes cerca del área de extractores de la ventilación. El análisis de cultivos bacterianos identificó múltiples organismos, pero el principal organismo de interés fue identificado como Erysipelothrix rhusiopathiae, cultivado a partir de hígado, pulmón, senos paranasales y de una barbilla inflamada de aves en la caseta afectada. El análisis histopatológico identificó bacterias grampositivas en forma de bastón en el bazo y el hígado (compatibles con septicemia bacteriana) confirmadas con tinción especial (tinción de Gram de Brown y Hopps). Se observó que estos organismos eran compatibles con E. rhusiopathiae; La infección por E. rhusiopathiae en pollos de engorde se presenta de forma esporádica y se asocia principalmente con sistemas de producción de pavos y/o cerdos.

Systemic Erysipelothrix rhusiopathiae in seven free-ranging delphinids stranded in England and Wales.

Microbiology records for 1127 cetaceans stranded on English and Welsh beaches and examined at the Institute of Zoology between 1990 and 2019 were reviewed to identify cases of Erysipelothrix rhusiopathiae, an uncommon but potentially fatal zoonotic pathogen. Once cases were identified, prevalence was calculated, corresponding postmortem reports were reviewed, common gross and histopathological findings were identified, and antibiotic susceptibilities were determined. Overall prevalence for E. rhusiopathiae was 0.62% (7/1127; 95% CI: 0.30-1.28%). It was isolated from 3 bottlenose dolphins Tursiops truncatus, 3 harbor porpoises Phocoena phocoena, and 1 short-beaked common dolphin Delphinus delphis, with a prevalence of 21.4% (3/14; 95% CI: 7.6-47.9%), 0.39% (3/779; 95% CI: 0.13-1.13%), and 0.47% (1/212; 95% CI: 0.08-2.62%) for each species, respectively. E. rhusiopathiae resulted in septicemia in all cases from which it was isolated. Gross necropsy findings included pulmonary edema (5/7), hemorrhage (5/7) and/or congestion of various organs (4/7), and serosanguineous effusion (3/7; pericardial: 3/7, pleural: 2/6, abdominal: 2/6). Congestion (5/5), bacterial emboli (4/5), and hemorrhage (4/5) were commonly observed on histopathology, and acute renal tubular injury (2/5) and pulmonary edema (2/5) were occasionally observed. Routine bacterial cultures were vital in identifying E. rhusiopathiae, since gross lesions were often subtle and nonspecific. The liver, kidney, and brain were key organs from which E. rhusiopathiae was consistently isolated. Antibiotic resistance was uncommon and was only observed for amikacin and trimethoprim sulfonamide. Penicillins were consistently effective, along with fluoroquinolones, macrolides, clindamycin, cephalexin, and oxytetracycline.

SEABIRDS AS POSSIBLE RESERVOIRS OF ERYSIPELOTHRIX RHUSIOPATHIAE ON ISLANDS USED FOR CONSERVATION TRANSLOCATIONS IN NEW ZEALAND.

Erysipelothrix rhusiopathiae, the causative agent of the disease erysipelas, is a gram-positive bacillus, and an opportunistic pathogen in diverse species of animals. In New Zealand, E. rhusiopathiae has killed endangered birds on offshore islands, including Kakapo (Strigops habroptilus), Takahe (Porphyrio hochstetteri), and Kiwi (Apteryx spp.). The source of infection is uncertain, and the prevalence of E. rhusiopathiae among wild birds is currently unknown. During October 2018 to December 2018, we surveyed dead and live seabirds that visit two of New Zealand's offshore islands used for Kakapo conservation with the goal of determining the prevalence of E. rhusiopathiae. Bone marrow from dead birds was cultivated on selective agar, and organisms cultured were identified using matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry. The prevalence of E. rhusiopathiae was calculated in different species for each island. We surveyed live birds using PCR with Erysipelothrix spp.-specific primers on blood samples. The prevalence of E. rhusiopathiae in dead seabirds on Whenua Hou and Te Hauturu-o-Toi was 3.4% (3/86) and 11.4% (5/44), respectively. On Whenua Hou, E. rhusiopathiae was detected in Sooty Shearwaters (Puffinus griseus; 5.9%, 2/34) and Mottled Petrels (Pterodroma inexpectata; 2.7%, 1/36) while it was detected only in Cook's Petrels (Pterodroma cookie; 13.5%, 5/37) on Te Hauturu-o-Toi. Blood samples were collected from two seabird species; only one of 50 Mottled Petrels (2.0%) was positive for the presence of Erysipelothrix spp. Our findings confirm that burrowing seabirds are possible reservoirs of E. rhusiopathiae on both islands studied and may be the source of spillover to other species on the island. The differences in observed prevalence suggest the species composition of the reservoir of E. rhusiopathiae may vary geographically.

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.

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.

Use of the rSpaA415 antigen indicates low rates of Erysipelothrix rhusiopathiae infection in farmed cattle from the United States of America and Great Britain.

BACKGROUND: Clinical cases of Erysipelothrix rhusiopathiae, a zoonotic gram-positive bacterium, have been reported in many ruminant species, including in cattle, deer, moose and muskoxen. Fatal cases have been repeatedly reported in cattle over the years but to date there is only one Japanese study investigating the seroprevalence of this bacterium in cattle using the growth agglutination test (GAT). This technique is subjective, time-consuming, expensive and hazardous compared to modern serological tests such as enzyme-linked immunosorbent assays (ELISA) or the newly developed fluorescent microbead-based immunoassays (FMIA). RESULTS: The FMIA based on the surface protein SpaA (rSpaA415) antigen of E. rhusiopathiae developed in this study had an almost perfect agreement with the GAT (k = 0.83) and showed a sensitivity of 89.7% and a specificity of 92.9% when compared to the GAT. Overall, detection rates of E. rhusiopathiae antibody positive samples were 13.8% (51/370) in British herds and 6% (12/200) in US herds. Positive cattle were present in 34.3% (24/70) of the investigated British farms and in 34.7% (8/23) of the US farms with an on-farm prevalence of 7.1 to 100% for the British farms and 8.3-30% for the US farms. CONCLUSIONS: FMIA is a fast, safe and economic alternative to the GAT for the diagnosis of E. rhusiopathiae in cattle. This work is the first seroprevalence study of E. rhusiopathiae in healthy farmed cattle in Great Britain and the US and revealed that infection occurs at a low level. Further investigations to evaluate risks of zoonotic transmission when handling cattle are needed.

Multiplex PCR assay for the simultaneous detection and differentiation of clonal lineages of Erysipelothrix rhusiopathiae serovar 1a strains currently circulating in Japan.

The species Erysipelothrixrhusiopathiae displays genetic heterogeneity; however, E. rhusiopathiae serovar 1a strains currently circulating in Japan exhibit remarkably low levels of genetic diversity and group into clonal sublineages of Lineage IVb (IVb-1 and IVb-2). In the present study, based on whole genome sequencing data, we designed primers for a multiplex PCR assay to simultaneously detect and differentiate the sublineages of E. rhusiopathiae strains. Among the one hundred and twenty-seven isolates of various serovar strains, including isolates from a wide range of hosts and geographic origins, the PCR assay could successfully detect and differentiate the serovar 1a strains belonging to the sublineages.

Erysipelothrix rhusiopathiae bloodstream infection - A 22-year experience at Mayo Clinic, Minnesota.

Erysipelothrix rhusiopathiae is a facultatively anaerobic Gram-positive bacillus found mostly in swine, fish and sheep. E. rhusiopathiae classically causes cutaneous eruptions in butchers, fish handlers and veterinarians. Based solely on case reports, 90% of E. rhusiopathiae bloodstream infections (BSI) have been associated with infective endocarditis (IE). To assess the true frequency of IE in E. rhusiopathiae BSI as well as other clinical associations, we performed a retrospective cohort analysis of E. rhusiopathiae BSI at Mayo Clinic. This is a single-centre, retrospective study conducted between 1/1/1994 and 20/6/2016 at Mayo Clinic in Rochester, MN. Medical records were reviewed for demographics, E. rhusiopathiae BSI, anti-microbial susceptibilities, incidence of IE, patient comorbidities, intensive care unit (ICU) admission and duration of antibiotics. Five cases of E. rhusiopathiae BSI were identified. Risk factors included animal exposures, immunosuppression, diabetes and kidney disease. All cases involved penicillin-sensitive strains and high-grade BSI. Four cases showed no signs of IE on transesophageal echocardiogram. All patients recovered fully with intravenous antibiotics. Our retrospective review illustrates that E. rhusiopathiae can cause invasive BSI in the absence of IE and that the previously reported 90% association between BSI and IE may be overestimated due to reporting bias. E. rhusiopathiae should be suspected in any patient with Gram-positive bacilli in blood cultures and the aforementioned risk factors. A limitation of our study was the low sample size, and future studies may involve multicentre collaborations and the use of polymerase chain reaction (PCR) or serologic testing to increase the number of diagnoses..

Serological surveillance for antibodies against Erysipelothrix species in wild boar and deer in Japan.

We investigated the seroprevalence of antibodies against Erysipelothrix in wild animals in Japan. Serum samples were collected from 48 wild boar, 26 Yezo deer and 26 Japanese deer in Japan. Growth agglutination (GA) test was performed to estimate antibody titers. As a result, positive results were obtained from 32 (66.7%), 1 (3.6%) and 6 (23.1%) samples from wild boar, Yezo deer and Japanese deer, respectively. Our findings suggest that wild animals may be an important reservoir of Erysipelothrix.

Erysipelas Outbreaks in Flocks of Geese in Poland--Biochemical and Genetic Analyses of the Isolates.

Erysipelothrix rhusiopathiae causes erysipelas in many vertebrate species. Severe disease outbreaks have been noted in many poultry species--chickens, ducks, emus, pheasants, pigeons, and geese. This article describes the biochemical and genetic analyses of six E. rhusiopathiae strains isolated from geese for meat production. The isolates came from birds kept in different poultry houses on one farm, and were collected during two erysipelas outbreaks. We analyzed and compared the isolates by random amplified polymorphic DNA with the use of NK6 primer and pulsed-field gel electrophoresis, with the restriction enzyme SmaI. Biochemical examination was performed with API Coryne test. Analyses showed that the three strains isolated during the first outbreak differed, whereas the three isolates from the second outbreak were identical to one another, but distinct from the isolates from the first outbreak. The results of biochemical and genetic analyses of E. rhusiopathiae strains isolated from geese suggest different sources of infection for the erysipelas outbreaks.

A combinational approach of multilocus sequence typing and other molecular typing methods in unravelling the epidemiology of Erysipelothrix rhusiopathiae strains from poultry and mammals.

Erysipelothrix rhusiopathiae infections re-emerged as a matter of great concern particularly in the poultry industry. In contrast to porcine isolates, molecular epidemiological traits of avian E. rhusiopathiae isolates are less well known. Thus, we aimed to (i) develop a multilocus sequence typing (MLST) scheme for E. rhusiopathiae, (ii) study the congruence of strain grouping based on pulsed-field gel electrophoresis (PFGE) and MLST, (iii) determine the diversity of the dominant immunogenic protein SpaA, and (iv) examine the distribution of genes putatively linked with virulence among field isolates from poultry (120), swine (24) and other hosts (21), including humans (3). Using seven housekeeping genes for MLST analysis we determined 72 sequence types (STs) among 165 isolates. This indicated an overall high diversity, though 34.5% of all isolates belonged to a single predominant ST-complex, STC9, which grouped strains from birds and mammals, including humans, together. PFGE revealed 58 different clusters and congruence with the sequence-based MLST-method was not common. Based on polymorphisms in the N-terminal hyper-variable region of SpaA the isolates were classified into five groups, which followed the phylogenetic background of the strains. More than 90% of the isolates harboured all 16 putative virulence genes tested and only intI, encoding an internalin-like protein, showed infrequent distribution. MLST data determined E. rhusiopathiae as weakly clonal species with limited host specificity. A common evolutionary origin of isolates as well as shared SpaA variants and virulence genotypes obtained from avian and mammalian hosts indicates common reservoirs, pathogenic pathways and immunogenic properties of the pathogen.

Exposure of extensively farmed wild boars (Sus scrofa scrofa) to selected pig pathogens in Greece.

BACKGROUND: Increased density and distribution of wild boar populations are likely to promote interactions and transmission of certain pathogens, not only among wild boar but also from wild boar to livestock or humans and vice versa. OBJECTIVE: The purpose of this study was to determine seroprevalence against seven selected pathogens in wild boar living in four different areas in Greece. ANIMALS AND METHODS: In total, 359 serum samples were collected from extensively farmed wild boar (Sus scrofa scrofa) originating from four distinct geographical areas throughout Greece from April 2012 to August 2013. Samples were tested for antibodies to Actinobacillus pleuropneumoniae, African swine fever virus (ASFV), Aujeszky's disease virus (ADV), classical swine fever virus (CSFV), Erysipelothrix rhusiopathiae, Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV). Prevalence was compared among the four regions using Fisher's exact test. RESULTS: Low overall seropositivities of 2.4% and 5.6% were detected for E. rhusiopathiae and PRRSV, respectively, higher ones for ADV (32.0%) and the highest (72.5% and 90.5%) for M. hyopneumoniae and A. pleuropneumoniae, respectively. All sera tested were found negative for antibodies directed against CSFV and ASFV. CONCLUSIONS: This is the first report of exposure of wild boars to selected pig pathogens in Greece. These results are indicative of the circulation of these pathogens in Greece with the exception of CSFV and ASFV and suggestive of the potential role of wild boars on their maintenance and transmission to their domestic counterparts and vice versa.

Characterization of Erysipelothrix rhusiopathiae strains isolated from acute swine erysipelas outbreaks in Eastern China.

Recently, a series of acute swine erysipelas outbreaks occurred in Eastern China. Eight strains isolated from cases of septicemia were determined as serotype 1a, and 4 of the isolates were resistant to acriflavine. One isolate strain named HX130709 was attenuated on agar media containing acriflavine dye. The 432-bp hypervariable region in spaA gene of the field and attenuated strains were amplified and sequenced. It was further compared with the vaccine strain G4T10, and thus, the eight field strains can be divided into four spaA-types. The partial spaA gene analysis also showed that no point mutations occurred among different archived passages of HX130709 during the attenuation. Results of pulsed-field gel electrophoresis showed that eight distinct patterns with 22 to 30 DNA fragment bands were produced from field strains, and twelve distinct patterns with 23 to 27 DNA fragment bands were produced from different passages of the attenuated strains. Mouse pathogenicity test showed that the mortality of the mice infected with 10(4) CFU field strains was 100% and the attenuation of strain HX130709 occurred between 46 and 50 passages. All the field and attenuated strains were highly sensitive to ß-lactam antibiotics, tetracyclines and macrolides. So, we can make conclusions that the acute swine erysipelas outbreaks in Eastern China were caused by serotype 1a E. rhusiopathiae strains with different biochemical characteristics, and the virulence of serotype 1a E. rhusiopathiae strains is unrelated with some point mutations in 432-bp hypervariable region of the spaA gene.

Acute and Chronic Erysipelothrix rhusiopathiae Infection in Lambs.

Polyarthritis caused by Erysipelothrix rhusiopathiae is a relatively common infection in lambs characterized by low mortality and high morbidity. E. rhusiopathiae is a ubiquitous Gram-positive bacterium that is both a commensal and a pathogen of vertebrates. The disease was studied during an outbreak in a Norwegian Spæl sheep flock. In the acute phase, 48 of 230 (20%) lambs developed clinical signs and 4 died (1.7%). One acute case was necropsied and E. rhusiopathiae was cultured from all major organs investigated and from joints. There was a fibrinous polyarthritis, increased presence of monocytes in vessels, and necrosis of Purkinje cells. Sixteen of the diseased animals (33%) developed a chronic polyarthritis. Eight of these lambs were necropsied; all had lesions in major limb joints, and 3 of 8 also had lesions in the atlanto-occipital joint. At this stage, E. rhusiopathiae was cultured only from the joints in 7 of 8 (87.5%) lambs, but by real-time polymerase chain reaction, we showed persistence of the bacterium in several organs. Pulsed-field gel electrophoresis typing of the bacterial isolates indicated that the same strain caused the acute and chronic disease. Five of 6 (83%) chronically affected animals had amyloidosis of the spleen, and 6 of 8 (75%) had amyloidosis of the liver. All chronically affected animals had a glomerulonephritis, and 6 of 8 (75%) had sparse degeneration in the brain. Ceruloplasmin and haptoglobin were significantly increased in the chronically diseased lambs. These results show that chronic ovine erysipelas is not restricted to joints but is a multisystemic disease.

Human Erysipelothrix rhusiopathiae Infection: Unsolved Issues and Possible Solutions.

Erysipelothrix rhusiopathiae infection in humans may not be as rare as previously thought. In most cases, the disease is acquired from animals through work-related exposure. Human infection has been reported since the early 1900's up to the present. Unsolved issues associated with this organism include inadequate disease control in animals, difficulty in identification and isolation of the bacteria, diagnostic delay due to unawareness of this uncommon disease or unfamiliarity with the increasingly diverse clinical manifestations, and inappropriate antibiotic use due to misdiagnosis, as well as drug resistance. In this review, we attempt to address the unsolved issues related to human Erysipelothrix infection and suggest possible solutions.

Virulence determinants, antimicrobial susceptibility, and molecular profiles of Erysipelothrix rhusiopathiae strains isolated from China.

The aim of this study was to understand the epidemiology, serotype, antibiotic sensitivity, and clonal structure of Erysipelothrix rhusiopathiae strains in China. Forty-eight strains were collected from seven provinces during the period from 2012 to 2013. Pulse-field electrophoresis identified 32 different patterns which were classified into clonal groups A­D. Most pulsed-field gel electrophoresis (PFGE) patterns were observed in clonal complex A and B, suggesting high diversity of genetic characterization in these two predominant clonal complexes. Antibiotic sensitivity test shows that all the stains were susceptible to ampicillin, erythromycin, and cefotaxime, and resistant to kanamycin, cefazolin, sulfadiazine, and amikacin. Erythromycin and ampicillin are recommended as first-line antibiotics for treatment of E. rhusiopathiae in China. The high variation in PFGE pattern among the main clonal groups shows that the E. rhusiopathiae in China may originate from different lineages and sources instead of from expansion of a single clonal lineage across different regions.

Erysipelothrix rhusiopathiae bacteremia without endocarditis associated with psoas abscess: the first case report in Thailand.

The authors report a patient with a rare manifestation of invasive septic Erysipelothrix rhusiopathiae infection without endocardial involvement. Our patient presented with progressive paraparesis and subacute fever for ten days. He had underlying diabetes mellitus and alcoholic cirrhosis. Magnetic resonance imaging (MRI) of the lumbosacral spine showed a psoas abscess with vertebral osteomyelitis and discitis at level of L23 of the lumbar spine. His blood culture grew E. rhusiopathiae. Transthoracic echocardiography demonstrated normal endocardium. Surgical drainage and debridement with concomitant intravenous antibiotics administration resulted in clinical improvement, including neurological status. MRI showed resolution of the psoas abscess and osteomyelitis. Erysipelothrix infection should be considered as a causative pathogen of musculoskeletal infection in immunocompromised patients. To our knowledge, this is the first case report of psoas abscess caused by E. rhusiopathiae in Thailand.

Erysipelothrix rhusiopathiae contamination in the poultry house environment during erysipelas outbreaks in organic laying hen flocks.

This study investigated organic laying hen farms for the presence of Erysipelothrix rhusiopathiae in the house environment and from potential carriers (i.e. insects and mice) during ongoing erysipelas outbreaks, and compared the obtained isolates with those from laying hens. The samples were investigated by selective culture followed by species-specific polymerase chain reaction on cultures. E. rhusiopathiae was isolated from the spleen, jejunal contents, manure, dust and swabs from water nipples. Three more samples from the house environment tested positive by polymerase chain reaction compared with selective culture alone. Selected isolates were investigated by pulsed-field gel electrophoresis (PFGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). One farm was represented by isolates from laying hens only, and one of these isolates differed in one PFGE band from the others. Different banding patterns were observed for isolates from laying hens and manure on one farm. On the remaining two farms, the isolates from the house environment and laying hens were identical but differed between farms. Outbreaks reoccurred in the next flock on two of the farms, and different PFGE types were isolated from consecutive flocks. Our results suggest an external source of infection, which would explain the previously reported increased risk of outbreaks in free-range flocks. Contaminated manure and dust may represent sources of transmission. For the isolates, MALDI-TOF MS and biochemical typing results were in agreement but, since the type strain of Erysipelothrix tonsillarum was typed as E. rhusiopathiae using MALDI-TOF MS, further studies into this method are needed.