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

Antimicrobial Resistance of Erysipelothrix rhusiopathiae Strains Isolated from Geese to Antimicrobials Widely Used in Veterinary Medicine

The aim of this study was to determine the antibiotic resistance of E. rhusiopathiae when isolated from clinical outbreaks of erysipelas in geese to antimicrobials commonly used in poultry production. All isolates were susceptible to amoxicillin alone or with clavulanic acid, with MIC values ranging from 0.016 to 0.125 μg/mL. Ninety-six percent of isolates were fully sensitive to penicillin G (MIC 0.125-0.5 μg/mL). All isolates were fully or moderately sensitive to erythromycin (MIC 0.125-0.5 μg/mL). Most E. rhusiopathiae isolates proved resistant to fluoroquinolones (76.6% of isolates were resistant to enrofloxacin, with MIC values ranging from 0.064 to 32 μg/mL, and 68% were resistant to norfloxacin, with MIC values ranging from 0.094 to 96 μg/mL), and tetracyclines (61.7% of isolates were resistant to doxycycline, with MIC values ranging from 0.25 to 64 μg/mL, and 63.8% were resistant to tetracycline, with MIC values ranging from 0.38 to 256 μg/mL). Point mutations in the gyrA gene (responsible for fluoroquinolone resistance) and the presence of the tetM gene (responsible for tetracycline resistance) were noted in most of the resistant isolates. Multidrug resistance, defined as resistance to at least one substance in three or more antimicrobial classes, was not observed.

Erysipelothrix rhusiopathiae infection by geese to human transmission

Erysipelothrix rhusiopathiae transmission to human is often occupation-related, but in most cases, a detailed case history is missing. This case report is based on an interdisciplinary approach and includes a thorough medical record. A 58-year-old laboratory technician working on geese necropsy cut open her glove at a rib fragment of a goose and subsequently noticed a slowly progressive, reddish skin alteration in the particular region of the hand. Bacteriological investigations on the geese revealed septicaemia due to E. rhusiopathiae and therefore substantiated the diagnosis of the patient. The infectious agent could not be cultured from the patient; however, antibiotic susceptibility testing was performed using the goose isolate. An entire follow-up until full recovery of the patient was conducted. Zoonotic infections possibly have a significant impact on certain occupations. This case report analyses a rare but important zoonotic infection to create awareness of this in physicians caring for human patients.

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.

Potential risk factors of swine erysipelas outbreak in Northeast Mainland China

Swine erysipelas is a common infectious disease that affects the pig-breeding industry. The purpose of this study was to elucidate the risk factors and their role in the prevalence of swine erysipelas so that one may be able to better prevent and control the swine erysipelas outbreaks in Northeast China. Using spatial clusters, the study area was divided into two parts: South Central Mainland China (hot spots) and Northeast Mainland China (potential outbreak areas). We investigated a total of 31 environmental factors and used the lasso regression and k-fold cross-validation methods to determine the main factors involved. Seven risk factors were determined to have a major impact on swine erysipelas. Multiple logistic regression was used to examine the contribution of these seven risk factors to the outbreak from 2008 to 2018, in the two research regions. In South Central Mainland China, where swine erysipelas was most prevalent, the extreme maximum temperature [OR = 1.143 (95%CI: 1.032-1.342)], total precipitation [OR = 2.298 (95%CI: 1.410-5.112)] and precipitation ≥0.1 mm [OR = 2.396 (95%CI: 1.329-5.941)] exhibited positive effects. The maximum wind speed [OR = 0.550 (95%CI: 0.303-0.775)] and concentration of O3-8H-90 per [OR = 0.876 (95%CI: 0.747-0.980)] exhibited negative effects. Summer was the main season for the erysipelas epidemic in South Central Mainland China. In Northeast China, only the total precipitation [OR = 1.048 (95%CI: 0.900-0.989)] was positively correlated with the prevalence of swine erysipelas, whereas the other factors were not significant. There was no obvious seasonal feature for the epidemic. Through the comparison and analysis of risk factors between the two research regions, more attention should be given to the impacts of high temperature and precipitation on the swine erysipelas epidemic in Northeast China.

Erysipelothrix Spp.: Past, Present, and Future Directions in Vaccine Research

Erysipelothrix spp. comprise a group of small Gram-positive bacteria that can infect a variety of hosts including mammals, fish, birds, reptiles and insects. Among the eight Erysipelothrix species that have been described to date, only Erysipelothrix rhusiopathiae plays a major role in farmed livestock where it is the causative agent of erysipelas. E. rhusiopathiae also has zoonotic potential and can cause erysipeloid in humans with a clear occupational link to meat and fish industries. While there are 28 known Erysipelothrix serovars, over 80% of identified isolates belong to serovars 1 or 2. Vaccines to protect pigs against E. rhusiopathiae first became available in 1883 as a response to an epizootic of swine erysipelas in southern France. The overall vaccine repertoire was notably enlarged between the 1940s and 1960s following major outbreaks of swine erysipelas in the Midwest USA and has changed little since. Traditionally, E. rhusiopathiae serovar 1a or 2 isolates were inactivated (bacterins) or attenuated and these types of vaccines are still used today on a global basis. E. rhusiopathiae vaccines are most commonly used in pigs, poultry, and sheep where the bacterium can cause considerable economic losses. In addition, erysipelas vaccination is also utilized in selected vulnerable susceptible populations, such as marine mammals in aquariums, which are commonly vaccinated at regular intervals. While commercially produced erysipelas vaccines appear to provide good protection against clinical disease, in recent years there has been an increase in perceived vaccine failures in farmed animals, especially in organic outdoor operations. Moreover, clinical erysipelas outbreaks have been reported in animal populations not previously considered at risk. This has raised concerns over a possible lack of vaccine protection across various production species. This review focuses on summarizing the history and the present status of E. rhusiopathiae vaccines, the current knowledge on protection including surface antigens, and also provides an outlook into future directions for vaccine development.

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.