Draft genome sequences of four Staphylococcus hyicus strains, SC302, SC304, SC306, and SC310, isolated from swine from Eastern Canada.

The bacterium Staphylococcus hyicus causes porcine exudative epidermitis in piglets, which represents both health and welfare concerns. Few genome sequences of this pathogen are published. We provide four additional ones to help future genomic analysis of S. hyicus. These are genomes of strains isolated from Canadian swine.

Antimicrobial Resistance Profile of Staphylococcus hyicus Strains Isolated from Brazilian Swine Herds.

Staphylococcus hyicus is the causative agent of porcine exudative epidermitis. This disorder affects animals in all producing countries and presents a widespread occurrence in Brazil. This study evaluated strains from a historical collection in order to detect the presence of exfoliative-toxin-encoding genes (SHETB, ExhA, ExhB, ExhC, ExhD), characterize the strains using PFGE, and determine their respective antimicrobial resistance profiles. The results obtained from the evaluation of 77 strains from 1982 to 1987 and 103 strains from 2012 reveal a significant change in resistance profiles between the two periods, especially regarding the antimicrobial classes of fluoroquinolones, amphenicols, lincosamides, and pleuromutilins. The levels of multidrug resistance observed in 2012 were significantly higher than those detected in the 1980s. It was not possible to correlate the resistance profiles and presence of genes encoding toxins with the groups obtained via PFGE. Only 10.5% of the strains were negative for exfoliative toxins, and different combinations of toxins genes were identified. The changes observed in the resistance pattern of this bacterial species over the 30-year period analyzed indicate that S. hyicus could be a useful indicator in resistance monitoring programs in swine production. In a country with animal protein production such as Brazil, the results of this study reinforce the need to establish consistent monitoring programs of antimicrobial resistance in animals, as already implemented in various countries of the world.

First Molecular Characterization of Siphoviridae-Like Bacteriophages Infecting Staphylococcus hyicus in a Case of Exudative Epidermitis.

Exudative epidermitis (EE), also known as greasy pig disease, is one of the most frequent skin diseases affecting piglets. Zoonotic infections in human occur. EE is primarily caused by virulent strains of Staphylococcus (S.) hyicus. Generally, antibiotic treatment of this pathogen is prone to decreasing success, due to the incremental development of multiple resistances of bacteria against antibiotics. Once approved, bacteriophages might offer interesting alternatives for environmental sanitation or individualized treatment, subject to the absence of virulence and antimicrobial resistance genes. However, genetic characterization of bacteriophages for S. hyicus has, so far, been missing. Therefore, we investigated a piglet raising farm with a stock problem due to EE. We isolated eleven phages from the environment and wash water of piglets diagnosed with the causative agent of EE, i.e., S. hyicus. The phages were morphologically characterized by electron microscopy, where they appeared Siphoviridae-like. The genomes of two phages were sequenced on a MiSeq instrument (Illumina), resulting in the identification of a new virulent phage, PITT-1 (PMBT8), and a temperate phage, PITT-5 (PMBT9). Sequencing of three host bacteria (S. hyicus) from one single farm revealed the presence of two different strains with genes coding for two different exfoliative toxin genes, i.e., exhA (2 strains) and exhC (1 strain). The exhC-positive S. hyicus strain was only weakly lysed by most lytic phages. The occurrence of different virulent S. hyicus strains in the same outbreak limits the prospects for successful phage treatment and argues for the simultaneous use of multiple and different phages attacking the same host.

In vitro antibacterial activity of plant essential oils against Staphylococcus hyicus and Staphylococcus aureus, the causative agents of exudative epidermitis in pigs.

Greasy pig disease or exudative epidermitis, a generalized or localized skin disease affecting piglets, is mainly caused by Staphylococcus hyicus, although other staphylococcal species such as Staphylococcus aureus may also induce disease. Piglets with skin lesions can be treated systemically with antibiotics. However, antimicrobial resistance to ß-lactam antibiotics are now frequently observed in S. hyicus and S. aureus isolates. In this study, the antibacterial activity of plant essential oils as well as their ability to potentiate the effect of several antimicrobial compounds against S. hyicus and S. aureus were investigated with a view to a potential use as skin disinfectants. Among ten essential oils tested, those from cinnamon, thyme, and winter savory were the most active with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values ranging from 0.078 to 0.313% (v/v). Using a fluorescent probe with DNA affinity, it was found that thyme and winter savory oils act, at least in part, by disturbing the bacterial membrane integrity. At concentrations below the MIC, thyme and winter savory oils reduced biofilm formation by S. hyicus. Moreover, a treatment of pre-formed biofilms of S. hyicus with cinnamon or thyme oils significantly decreases its viability. Synergistic interactions between essential oils, more particularly from thyme and winter savory, and penicillin G, chlorhexidine or nisin, were observed. This study supports the therapeutic potential of essential oils as topical therapeutic agents against exudative epidermitis.

Autogenous vaccination reduces antimicrobial usage and mortality rates in a herd facing severe exudative epidermitis outbreaks in weaned pigs.

This study was conducted in a commercial 1000-sow herd facing recurrent exudative epidermitis (EE) outbreaks during the nursery period and assessed the efficacy of autogenous vaccination in controlling such outbreaks. The vaccine was produced using three Staphylococcus hyicus isolates recovered from affected pigs shortly before the onset of the study. All of those isolates were positive for the exhB gene, which encodes the exfoliative toxin type B (ExhB). From four consecutive farrowing batches of sows, two batches were vaccinated (V) against S hyicus at five and two weeks before farrowing, and two sow batches remained non-vaccinated (NV). Vaccination efficacy was primarily determined by the levels of metaphylactic antimicrobial usage, and the morbidity and mortality data for the pigs of the V and NV sows. The total amount of antimicrobials used metaphylactically against EE in pigs among the V and NV farrowing batches was 39,600 and 88,550 mg, respectively. The used daily dose pig to animal daily dose pig ratio for the V and NV batches were 1.31 and 1.79, respectively (a ratio of 0.8 to 1.2 is indicative of correct dosing). The morbidity and mortality rates were V=6.50 and NV=14.36 (P=0.008), and V=2.59 and NV=5.02 (P=0.000), respectively. To conclude, autogenous vaccination of the sows with a vaccine based on exhB-positive S hyicus isolates reduced metaphylactic treatment with antimicrobials as well as the morbidity and mortality rates in weaned pigs compared with pigs from NV sow batches.

Assessment of different storage conditions for Staphylococcus hyicus survival.

INTRODUCTION: Collecting swabs from skin lesions for bacteriological examination is frequently performed to the diagnosis of exudative epidermitis. This method is fast and non-invasive, but it depends directly on the viability of bacteria in clinical samples, which can be influenced by storage and shipment temperatures and the time of transportation. The aim of this study was to assess the capacity of four commercial transport media and swabs with no transport medium to preserve Staphylococcus hyicus (S. hyicus) for up to 10 days at room temperature and under refrigeration. METHODOLOGY: Samples were stored in swabs with no transport medium and four transport media (Amies, Amies with charcoal, Cary Blair and Stuart) for 10 days at room temperature and under refrigeration. Swabs were plated in Tween 80 Agar and colonies counted. RESULTS: Samples kept in transport media showed better performance (P < 0.05) under refrigeration. Storage under refrigeration in Amies medium showed better results than all other transport media and swabs (P < 0.05). Amies medium and swabs with no transport medium showed comparable results in room temperature (P > 0.05). In additional, refrigerated Amies medium and swabs with no transport medium at room temperature showed high performance for up to nine and three storage days, respectively. CONCLUSIONS: The recovery of S. hyicus in samples stored in Amies medium under refrigeration was higher when compared to other transport media. In addition, swabs with no transport medium could also be indicated when samples are stored at room temperature within three days.

Exudative epidermitis of piglets caused by non-toxigenic Staphylococcus sciuri.

Infections with strains of Staphylococcus sciuri are a potential threat to animal and public health, and a cause for considerable concern. We isolated and identified S. sciuri as a pathogen from an acute outbreak of exudative epidermitis in piglets for further genetic identification using experimental infections. The results of this study showed that S. sciuri strain NJ1306 reproduced exudative epidermitis in experimentally infected 5-day-old piglets. The isolated bacteria also caused sudden death in BALB/c mice following intraperitoneal injection with 5×108 CFU of the isolate. The data indicated that strain NJ1306 of S. sciuri was pathogenic to piglets and mice, and the study provided the first known report of clinical lung lesions and endocarditis in piglets due to S. sciuri.

Distribution of the putative virulence factor encoding gene sheta in Staphylococcus hyicus strains of various origins

In the present study, Staphylococcus (S.) hyicus strains isolated in Russia (n = 23) and Germany (n = 17) were investigated for the prevalence of the previously described genes sheta and shetb. Sheta was detected in 16 S. hyicus strains. Sheta-positive strains were mainly found among strains isolated from exudative epidermitis, and frequently together with the exfoliative toxin-encoding genes exhD and exhC. Partial sequencing of sheta in a single S. hyicus strain revealed an almost complete match with the sheta sequence obtained from GenBank. None of the S. hyicus strains displayed a positive reaction with the shetb-specific oligonucleotide primer used in the present study. According to the present results, the exotoxin encoding gene sheta seems to be distributed among S. hyicus strains in Russia and Germany. The toxigenic potential of this exotoxin, which does not have the classical structure of a staphylococcal exfoliative toxin, remains to be elucidated.

Interaction of Staphylococcus hyicus and an inhibitor producing strain of Staphylococcus chromogenes on the skin of gnotobiotic piglets.

Abstract- The effects of an inhibitor-producing strain of Staphylococcus chromogenes on the colonisation and disease produced by virulent and avirulent strains of Staphylococcus hyicus were examined. In the presence of S. chromogenes the colonisation of the virulent strain was reduced one thousand fold and the onset of lesions was delayed by 7 days. The ability of the avirulent strain of S. hyicus to colonise skin was greatly reduced and populations became almost undetectable within 6 days of inoculation. Résumeé- Les effets d'une souche de Staphylococcus chromogenes, productrice d'un facteur d'inhibition, ont été examinés sur la colonisation et la maladie produites par des souches non virulentes et virulentes de Staphylococcus hyicus. En présence de S. chromogenes, la colonisation de la souche virulente a été réduite de 1000 fois, et l'apparition des lésions a été retardée de 7 jours. La faculté pour la souche non virulente de S. hyicus de coloniser la peau a été considérablement réduite et les populations sont devenues à peu près introuvables 6 jours après l'inoculation. Zusammenfassung- Die Wirkungen Inhibitor-produzierenden Art von Staphylococcus chromogenes auf die Kolonisierung und Erkrankung der Haut durch virulente und avirulente Arten von Staphylococcus hyicus wurden untersucht. In Gegenwart von S. chromogenes wurde die Kolonisierung der virulenten Art um den Faktor 1000 verringert und des Auftreten der Hautveränderungen um 7 Tage verzögert. Die Fähigkeit zur Kolonisierung der Haut durch die avirulente 5. hyicus-Art wurde sehr stark verringert, ihre Population konnte innerhalb von 6 Tagen nach Inokulation nicht mehr nachgewiesen werden. Resumen Se estudian los efectos de una cepa de Staphylococcus chromogenes productora de un inhibidor sobre la colonización y la enfermedad producida por cepas virulentas y avirulentas de Staphylococcus hyicus. En presencia de S. chromogenes la colonización de cepas virulentas se redujo a una milésima parte y la aparición de lesiones se retrasó 7 días. La capacidad de cepas avirulentas de S. hyicus para colonizar la piel se vió fuertemente reducida y las poblaciones bacterianas eran prácticamente no detectables a los 6 días de la inoculación.

Studies on the Virulence of Staphylococcus hyicus.

Abstract- Culture supernatants from six Staphylococcus hyicus isolates were concentrated by ultrafiltration and were injected intradermally into the abdominal skin of 2-week-old piglets. Two distinct types of reaction were observed; (1) a focal erythema and (2) an exfoliative reaction with crusting. The severity of these reactions and the number of animals affected differed between isolates. The exfoliative reaction observed in these skin tests may be a good indicator of virulence. Résumé- Les surnageants de six souches de Staphylococcus hyicus ont été concentrés par ultrafiltration et furent injectés par voie intradermique dans la peau de l'abdomen de porcelets ägés de deux semaines. Deux types distincts de réactions furent observés: (1) un éryhème focal et (2) une réaction d'exfoliation avec apparition de croûtes. L'intensité de ces réactions et le nombre d'animaux atteints différaient selon les souches. La réaction d'exfoliation observée lors de ces tests pourrait être un bon indicateur de virulence. Zusammenfassung- Überstände der Kultur von sechs Staphylococcus hyicus-Isolaten wurden durch Ultra-zentrifugieren konzentriert und bei 2 Wochen alten Ferkeln intradermal in die Abdominalhaut injiziert. Es konnten zwei deutlich unterscheidbare Reaktionen beobachtet werden: (1) ein fokales Erythem und (2) eine exfoliative Reaktion mit Krustenbildung. Die Schwere dieser Reaktionen und die Zahl der betroffenen Tiere war je nach Isolat unterscheidlich. Die exfoliative Reaktion bei diesen Hauttests könnte ein guter Indikator für die Virulenz sein. Resumen Los sobrenadantes de 6 cultivos diferentes de Staphylococcus hyicus se concentraron mediante ultrafiltración y se inyectaron via intradérmica en la piel abdominal de lechones de dos semanas de edad. Se observaron dos tipos de reacción: (1) un eritem focal y (2) una reacción exfoliativa y costrosa. La gravedad de las reacciones y el nümero de animales afectados variaba en functión del cultivo utilizado. La reacción exfoliativa que se observó en estos tests intradérmicos puede ser un buen indicador de virulencia.