Possible virulence factors of Staphylococcus sciuri

In vitro antimicrobial and antibiofilm activity of phage cocktail against Mammaliicoccus sciuri, a causative agent of bovine mastitis

In this research paper the in vitro antimicrobial and antibiofilm activity of phage cocktail against the coagulase negative Mammaliicoccus sciuri was investigated. Three M. sciuri isolates obtained from clinical bovine mastitis samples were characterized and identified by 16S rRNA gene sequencing. Bacteriophages with lytic activity against M. sciuri isolates were isolated from dairy farm effluents. Two typical phages were isolated using standard enrichment and plaque assay techniques, purified by polyethylene glycol precipitation, and morphologically characterized based on shape and size using transmission electron microscopy. This was followed by determination of host range using spot tests and stability to varying temperature, pH and UV treatment. The phage cocktail suppressed bacterial activity within 30 min of exposure. Crystal violet assay showed that the tested phages and their cocktail significantly reduced the biofilm biomass of all three M. sciuri strains compared to the untreated control in vitro within 24 h with a single dosing. Transmission electron micrography of the purified phage particle revealed an icosahedral head and a rigid contractile tail, characteristic of the class Caudoviricetes. The findings open new avenues in phage-based antimicrobial approaches for controlling contagious and teat skin opportunistic bacteria causing bovine mastitis.

Virulence determinants and antibiotic resistance in staphylococci isolated from the skin of captive bred reptiles

Knowledge of the composition and properties of skin microbiota in healthy reptiles is essential for preservation strategies and thus the prevention of skin dysbiosis leading to dermatological diseases. Despite the greatly increasing popularity of reptiles as pets, only a few studies have dealt with this topic. Therefore, the aim of this work was to analyse species composition of bacteria isolated from skin swabs of 40 reptiles (17 species) using MALDI-TOF spectrometry and to characterise the virulence properties of identified staphylococci (n = 51). The most common species were Staphylococcus xylosus and S. sciuri. Bacilli, enterococci, Escherichia coli, Salmonella sp. and Acinetobacter sp. were also common. The most frequent antimicrobial resistance in staphylococcal isolates was observed for ampicillin (100.0%) and cefoxitin (98.0%) with the blaZ gene being most prevalent (58.8%). In contrast, all staphylococci were susceptible to gentamicin, kanamycin and imipenem. Slime and biofilm production was observed in 86.3% and 76.5% of isolates, respectively. Gelatinase, DNase, protease and lipase activity was found more rarely (41.2%; 25.5%; 27.5% and 21.6%). Since reptiles are a reservoir of bacteria for their owners, common multi-drug resistance (84.3%, MAR index average 0.29 ± 0.09) and biofilm formation must be kept in mind, especially in the case of injury when handling reptiles.

Staphylococcus xylosus and Staphylococcus aureus as commensals and pathogens on murine skin

Skin ulcers, skin dermatitis and skin infections are common phenomena in colonies of laboratory mice and are often found at increased prevalence in certain immunocompromised strains. While in many cases these skin conditions are mild, in other cases they can be severe and lead to animal morbidity. Furthermore, the presence of skin infections and ulcerations can complicate the interpretation of experimental protocols, including those examining immune cell activation. Bacterial species in the genus Staphylococcus are the most common pathogens recovered from skin lesions in mice. In particular, Staphylococcus aureus and Staphylococcus xylosus have both been implicated as pathogens on murine skin. Staphylococcus aureus is a well-known pathogen of human skin, but S. xylosus skin infections in humans have not been described, indicating that there is a species-specific difference in the ability of S. xylosus to serve as a skin pathogen. The aim of this review is to summarize studies that link S. aureus and S. xylosus to skin infections of mice and to describe factors involved in their adherence to tissue and their virulence. We discuss potential differences in mouse and human skin that might underlie the ability of S. xylosus to act as a pathogen on murine skin, but not human skin. Finally, we also describe mouse mutants that have shown increased susceptibility to skin infections with staphylococcal bacteria. These mutants point to pathways that are important in the control of commensal staphylococcal bacteria. The information here may be useful to researchers who are working with mouse strains that are prone to skin infections with staphylococcal bacteria.

Microbial Profiling of Amniotic Fluid, Umbilical Blood and Placenta of the Foaling Mare

The presence of a microbiome/microbiota in the placenta is hotly debated. In previous studies, the presence of bacteria in equine amniotic fluid and umbilical blood was independent of foal health. The objective of the present study was to determine if the same bacteria are present in the equine placenta as in amniotic fluid and umbilical blood. Samples were obtained from 24 parturient mares and foals. Placental bacterial DNA was extracted, and the microbiome was identified using 16S rRNA sequencing. All amniotic fluid samples contained some polymorphonucleocytes; bacteria were isolated from four samples. Aerobic or anaerobic growth was found in 18 and 3 umbilical blood samples, respectively. Serum amyloid A was <5 mg/L in all 24 samples, total WBC varied between 2900 and 10,700/µL, and fibrinogen varied between 0 and 5.16 g/L. In jugular blood, serum amyloid A was <5 mg/L in all 24 foals, total white blood count was 3200 to 8100/µL, and fibrinogen was 0.44 to 4.42 g/L. The diversity of bacterial microbiota was similar in all placental regions at the phylum level but differed at the genus level; the most abundant phyla were Proteobacteria (42-46.26%) and Actinobacteria (26.91-29.96%). In conclusion, bacteria were found in the fetal compartments and placenta of healthy equine pregnancies; however, we can neither prove nor disprove the hypothesis that the placenta has its own microbiome.

Disruption of the intestinal barrier exacerbates experimental autoimmune pancreatitis by promoting the translocation of Staphylococcus sciuri into the pancreas

Autoimmune pancreatitis (AIP) and IgG4-related disease (IgG4-RD) are new disease entities characterized by enhanced IgG4 antibody responses and involvement of multiple organs, including the pancreas and salivary glands. Although the immunopathogenesis of AIP and IgG4-RD is poorly understood, we previously reported that intestinal dysbiosis mediates experimental AIP through the activation of IFN-α- and IL-33-producing plasmacytoid dendritic cells (pDCs). Because intestinal dysbiosis is linked to intestinal barrier dysfunction, we explored whether the latter affects the development of AIP and autoimmune sialadenitis in MRL/MpJ mice treated with repeated injections of polyinosinic-polycytidylic acid [poly (I:C)]. Epithelial barrier disruption was induced by the administration of dextran sodium sulfate (DSS) in the drinking water. Mice co-treated with poly (I:C) and DSS, but not those treated with either agent alone, developed severe AIP, but not autoimmune sialadenitis, which was accompanied by the increased accumulation of IFN-α- and IL-33-producing pDCs. Sequencing of 16S ribosomal RNA revealed that Staphylococcus sciuri translocation from the gut to the pancreas was preferentially observed in mice with severe AIP co-treated with DSS and poly (I:C). The degree of experimental AIP, but not of autoimmune sialadenitis, was greater in germ-free mice mono-colonized with S. sciuri and treated with poly (I:C) than in germ-free mice treated with poly (I:C) alone, which was accompanied by the increased accumulation of IFN-α- and IL-33-producing pDCs. Taken together, these data suggest that intestinal barrier dysfunction exacerbates AIP through the activation of pDCs and translocation of S. sciuri into the pancreas.

Frequent dissemination and carriage of an SCCmec-mecC hybrid in methicillin-resistant Mammaliicoccus sciuri in farm animals from Tunisia

OBJECTIVES

In this study, we aimed to assess the extent of dissemination of methicillin-resistant Mammaliicoccus sciuri in animal farms in Tunisia and evaluate the distribution of virulence and methicillin resistance genes in the M. sciuri population.

METHODS

Staphylococci and mammaliicocci isolated from unhealthy animals and healthy humans from adjacent farms in Tunisia were characterized for antimicrobial susceptibility, biofilm formation, agglutination, and hemolysis abilities. Mammaliicoccus sciuri relatedness and content in antibiotic resistance and virulence genes were analyzed by whole-genome sequencing (WGS).

RESULTS

Mammaliicoccus sciuri was the most prevalent species (46.2%), showing the highest resistance rates to fusidic acid (94.6%), oxacillin (73%), penicillin (40.5%), clindamycin (37%), ciprofloxacin (27%), and cefoxitin (24.3%). Some isolates carried genes encoding resistance to nine different antibiotic classes. mecA was found in 35% of M. sciuri and mecC in 16.2%. All isolates carrying mecC were of S. sciuri subspecies carnaticus and carried the hybrid element SCCmec-mecC. Mammaliicoccus sciuri were able to produce strong biofilm (27%) and have clumping ability (16%). Additionally, they carried genes for capsule production (cap8, 100%), iron-regulated surface determinants (isdE, 24%; isdG, 3%), and virulence regulation (clpC and clpP, 100%). Single nucleotide polymorphisms (SNPs) analysis showed that 17 M. sciuri cross-transmission events probably occurred between different animal species and farms. Moreover, SCCmec was estimated to have been acquired five times by S. sciuri subsp. carnaticus.

CONCLUSION

Multidrug resistant and pathogenic M. sciuri were frequently disseminated between different animal species within the farm environment. mecA and mecC can be disseminated by both frequent acquisition of the SCCmec element and clonal dissemination.

Molecular assessment of microbial diversity on eggshell of chukar partridges (Alectoris chukar) under semi-captive conditions

Due to human activity, climatic changes and habitat damage, the Chukar partridge (Alectoris chukar) is experiencing a population decrease. The goal of this work was to isolate and identify the inner eggshell microflora in order to learn more about their function in A. chukar embryo mortality and hatchability in semi-captive settings. During the egg-laying season, 204 eggs were gathered from the Balkasar Research Complex in Chakwal, Pakistan. These eggshells were divided into four categories after incubation: un-pricked with dead embryo, pricked with dead embryo, hatched, and unfertilized eggs. A total of 47 (23.03%) samples tested positive for gram-positive bacteria, which were then identified using 16S rRNA sequence analysis. Bacillus subtilis, Bacillus cereus, Bacillus amyloliquefaciens, Bacillus toyonensis, Bacillus thuringiensis and Staphylococcus sciuri were among the identified species. Hatched eggshells had the highest percentage of bacterial flora (36.17%), followed by un-pricked with dead embryo (23.40%) and pricked with death embryo (21.27%), and unfertilized eggshells had the lowest percentage (19.14%). As a result, the findings of this study revealed that microbial contamination of eggshells could be a cause of early embryonic stage degeneration and bird death.

Genome-based characterization of a plasmid-associated micrococcin P1 biosynthetic gene cluster and virulence factors in Mammaliicoccus sciuri IMDO-S72

Analysis of the de novo assembled genome of Mammaliicoccus sciuri IMDO-S72 revealed the genetically encoded machinery behind its earlier reported antibacterial phenotype and gave further insight into the repertoire of putative virulence factors of this recently reclassified species. A plasmid-encoded biosynthetic gene cluster was held responsible for the antimicrobial activity of M. sciuri IMDO-S72, comprising genes involved in thiopeptide production. The compound encoded by this gene cluster was structurally identified as micrococcin P1. Further examination of its genome highlighted the ubiquitous presence of innate virulence factors mainly involved in surface colonization. Determinants contributing to aggressive virulence were generally absent, with exception of a plasmid-associated ica cluster. The native antibiotic resistance genes sal(A) and mecA were detected within the genome, amongst others, but were not consistently linked with a resistant phenotype. While mobile genetic elements were identified within the genome, such as an untypeable SCC element, they proved to be generally free of virulence- and antibiotic-related genes. These results further suggest a commensal lifestyle of M. sciuri and indicate the association of antibiotic resistance determinants with mobile genetic elements, as an important factor in conferring antibiotic resistance, in addition to their unilateral annotation. Importance Mammaliicoccus sciuri has been put forward as an important carrier of virulence and antibiotic resistance genes, which can be transmitted to clinically important staphylococcal species such as Staphylococcus aureus. As a common inhabitant of mammal skin, this species is believed to have a predominant commensal lifestyle although it has been reported as an opportunistic pathogen in some cases. This study provides an extensive genome-wide description of its putative virulence potential taking into consideration the genomic context in which these genes appear, an aspect that is often overlooked during virulence analysis. Additional genome and biochemical analysis linked M. sciuri with the production of micrococcin P1, gaining further insight to which extent these biosynthetic gene cluster are distributed amongst different related species. The frequent plasmid-associated character hints that these traits can be horizontally transferred and might confer a competitive advantage to its recipient within its ecological niche.

Virulence Characteristics of mecA-Positive Multidrug-Resistant Clinical Coagulase-Negative Staphylococci

Coagulase-negative staphylococci (CoNS) are an important group of opportunistic pathogenic microorganisms that cause infections in hospital settings and are generally resistant to many antimicrobial agents. We report on phenotypic and genotypic virulence characteristics of a select group of clinical, mecA-positive (encoding penicillin-binding protein 2a) CoNS isolates. All CoNS were resistant to two or more antimicrobials with S. epidermidis strain 214EP, showing resistance to fifteen of the sixteen antimicrobial agents tested. Aminoglycoside-resistance genes were the ones most commonly detected. The presence of megaplasmids containing both horizontal gene transfer and antimicrobial resistance genetic determinants indicates that CoNS may disseminate antibiotic resistance to other bacteria. Staphylococcus sciuri species produced six virulence enzymes, including a DNase, gelatinase, lipase, phosphatase, and protease that are suspected to degrade tissues into nutrients for bacterial growth and contribute to the pathogenicity of CoNS. The PCR assay for the detection of biofilm-associated genes found the eno (encoding laminin-binding protein) gene in all isolates. Measurement of their biofilm-forming ability and Spearman’s rank correlation coefficient analyses revealed that the results of crystal violet (CV) and extracellular polymeric substances (EPS) assays were significantly correlated (ρ = 0.9153, P = 3.612e-12). The presence of virulence factors, biofilm-formation capability, extracellular enzymes, multidrug resistance, and gene transfer markers in mecA-positive CoNS clinical strains used in this study makes them powerful opportunistic pathogens. The study also warrants a careful evaluation of nosocomial infections caused by CoNS and may be useful in studying the mechanism of virulence and factors associated with their pathogenicity in vivo and developing effective strategies for mitigation.

Virulence and toxigenicity of coagulase-negative staphylococci in Nigerian traditional fermented foods

The incidence of coagulase-negative staphylococci (CoNS) may render food unsafe, as the clinical isolates have been reported to exude virulent traits. A total of 255 CoNS isolates from 6 traditional fermented foods (nono, kunu, wara, iru, ogi, and kindirmo) from North Central Nigeria, identified as Staphylococcus epidermidis, Staphylococcus simulans, Staphylococcus xylosus, Staphylococcus kloosii, and Staphylococcus caprae, were investigated for virulence traits. The strains were examined for biofilm formation and production of hyaluronidase, DNase, TNase, haemolysins, and superantigenic toxins (SEA, SEB, SEC, SED, and TSST-1) using standard and genotypic methods. The analysis of virulence factors revealed the production of slime in 200 isolates (78.4%); α-haemolysin in 136 (53.3%); β-haemolysin in 43 (16.9%); DNase in 199 (78.0%); TNase in 29 (11.4%); hyaluronidase in 125 (49.0%); TSST-1 in 119 (46.7%); and enterotoxin-producing isolates SEA, SEB, SEC, and SED in 61 (23.9%), 19 (7.5%), 9 (3.5%), and 8 (3.1%), respectively. PCR analysis detected tsst-1, sea, seb, and sec genes. The ability of these microorganisms to exhibit virulence evokes the potential to cause disease especially under determinate conditions or in immune-compromised patients. The occurrence of CoNS in food should not be ignored nor their pathogenic potential considered as insignificant, rather safety measures should be taken to reduce or totally eliminate their occurrence in foods.

Antimicrobial Resistance, Biofilm Formation and mecA Characterization of Methicillin-Susceptible S. aureus and Non-S. aureus of Beef Meat Origin in Egypt

Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA), and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterization in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB, and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%), and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius, and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus. Although, global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates, that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which could be a source of perilous S. aureus for the human community.

Microbiological and molecular characterization of human clinical isolates of Staphylococcus cohnii, Staphylococcus hominis, and Staphylococcus sciuri

BACKGROUND

The incidence of coagulase-negative staphylococci reported as causative agents of nosocomial infections has risen in the last decade. The aim of this study was to characterize biofilm formation, antibiotic resistance, SCCmec type, and genetic relatedness in clinical isolates of Staphylococcus cohnii, Staphylococcus hominis, and Staphylococcus sciuri recovered from humans.

METHODS

Clinically relevant isolates of S. cohnii (n = 15), S. hominis (n = 9), and S. sciuri (n = 6), were collected from patients. Biofilm formation was evaluated using crystal violet staining, drug susceptibility was assessed using the broth microdilution method, and methicillin resistance was measured using the cefoxitin disk test. SCCmec was typed using 2 different methodologies, and genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE).

RESULTS

Sixty percent (9/15) of S. cohnii, 33% (3/9) of S. hominis, and 50% (3/6) of S. sciuri isolates were categorized as weak producers of biofilm. None of the isolates were resistant to vancomycin or linezolid. All 3 species showed a high resistance (> 66%) to ampicillin, levofloxacin, erythromycin, and ceftriaxone, and the majority of the isolates were methicillin-resistant. PFGE revealed that the S. cohnii isolates comprised 1 dominant clone.

CONCLUSIONS

The S. cohnii, S. hominis, and S. sciuri isolates analyzed in this study showed a high methicillin resistance and resistance to other antimicrobials. The results of this study strongly suggest that coagulase-negative staphylococci harbour new SCCmec elements. We report the first case of a clone of S. cohnii associated with human disease.

Staphylococcus sciuri exfoliative toxin C (ExhC) is a necrosis-inducer for mammalian cells

Staphylococcus sciuri (S. sciuri) is a rare pathogen in humans, but it can cause a wide array of human infections. Recently a S. sciuri isolate (HBXX06) was reported to cause fatal exudative epidermitis (EE) in piglets and thus considered as a potential zoonotic agent. To investigate the pathogenicity of this bacterium, we cloned exfoliative toxin C (ExhC), a major toxin of the S. sciuri isolate and performed functional analysis of the recombinant ExhC-his (rExhC) protein using in vitro cell cultures and newborn mice as models. We found that rExhC could induce necrosis in multiple cell lines and peritoneal macrophages as well as skin lesions in newborn mice, and that the rExhC-induced necrosis in cells or skin lesions in newborn mice could be completely abolished if amino acids 79-128 of rExhC were deleted or blocked with a monoclonal antibody (3E4), indicating aa 79-128 portion as an essential necrosis-inducing domain. This information contributes to further understandings of the mechanisms underlying S. sciuri infection.

Identification and antimicrobial resistance of microflora colonizing feral pig (Sus scrofa) of Brazilian Pantanal

Antimicrobial resistance of bacteria is a worldwide problem affecting wild life by living with resistant bacteria in the environment. This study presents a discussion of outside factors environment on microflora of feral pigs (Sus scrofa) from Brazilian Pantanal. Animals had samples collected from six different body sites coming from two separated geographic areas, Nhecolandia and Rio Negro regions. With routine biochemical tests and commercial kits 516 bacteria were identified, with 240 Gram-positive, predominantly staphylococci (36) and enterococci (186) strains. Among Gram-negative (GN) bacteria the predominant specimens of Enterobacteriaceae (247) mainly represented by Serratia spp. (105), Escherichia coli (50), and Enterobacter spp. (40) and specimens not identified (7). Antimicrobial susceptibility was tested against 17 drugs by agar diffusion method. Staphylococci were negative to production of enterotoxins and TSST-1, with all strains sensitive towards four drugs and highest resistance toward ampicillin (17%). Enterococci presented the highest sensitivity against vancomycin (98%), ampicillin (94%) and tetracycline (90%), and highest resistance pattern toward oxacillin (99%), clindamycin (83%), and cotrimoxazole (54%). In GN the highest resistance was observed with Serratia marcescens against CFL (98%), AMC (66%) and AMP (60%) and all drugs was most effective against E. coli SUT, TET (100%), AMP, TOB (98%), GEN, CLO (95%), CFO, CIP (93%). The results show a new profile of oxacillin-resistant enterococci from Brazilian feral pigs and suggest a limited residue and spreading of antimicrobials in the environment, possibly because of low anthropogenic impact reflected by the drug susceptibility profile of bacteria isolated.

Extracellular DNase activity of Cryptococcus neoformans and Cryptococcus gattii

Extracellular DNase activity was studied in 73 strains of Cryptococcus neoformans and 12 strains of Cryptococcus gattii. DNase activity was measured by DNase agar clearance with and without Methyl Green. All strains tested showed extracellular DNase activity and no significant difference was found betweenC. neoformans and C. gattii strains. DNase production was higher in strains from clinical origin (average radius of 6.2 mm) than among environmental strains (average radius of 2.9 mm). The extracellular enzyme may be detected by DNA substrate PAGE assays and its molecular weight was estimated at 31 kD. These results suggest that extracellular DNase could be considered as a virulence factor involved in C. neoformans-C. gattii species complex pathogenicity.

Evolution of slime production by coagulase-negative staphylococci and enterotoxigenic characteristics of Staphylococcus aureus strains isolated from various human clinical specimens

The present study was designed to determine the slime production of coagulase-negative staphylococci (CoNS) and the enterotoxigenic properties of Staphylococcus aureus strains, and to evaluate the clinical importance of slime-producing CoNS and enterotoxigenic S. aureus strains isolated from various human clinical specimens. For this purpose, a total of 120 Staphylococcus strains were isolated and identified, and further characterized for their slime production and enterotoxigenicity. Of the clinical isolates, 55 (45.8 %) were found to be S. aureus, and the others (54.2 %) were identified as CoNS. Of the CoNS, 20 (16.7 %) were further identified as Staphylococcus hominis, 18 (15 %) as Staphylococcus epidermidis, six (5 %) as Staphylococcus xylosus, six (5 %) as Staphylococcus warneri, five (4.2 %) as Staphylococcus sciuri, four (3.3 %) as Staphylococcus haemolyticus, and two each (1.7 %) as Staphylococcus simulans, Staphylococcus capitis and Staphylococcus saprophyticus, respectively. Thirty-nine (60 %) of 65 CoNS were found to be slime producers. Slime production was observed in all CoNS, except S. capitis, mostly from blood (38.5 %), tracheal aspiration (20.5 %) and urine (12.8 %) specimens. In addition, of the 55 S. aureus isolates, 46 (83.6 %) were found to be enterotoxigenic, and of these S. aureus strains, 39 (84.7 %) were positive for staphylococcal enterotoxin (SE)A. The results of this study showed that the slime-producing CoNS were mostly found in clinical specimens of blood, tracheal aspirate and urine. SEA was the predominant enterotoxin type detected in S. aureus strains from human clinical specimens.

A highly pathogenic strain of Staphylococcus sciuri caused fatal exudative epidermitis in piglets

Staphylococcus sciuri are important human pathogens responsible for endocarditis, peritonitis, septic shock, urinary tract infection, pelvic inflammatory disease and wound infections. However, little information is known regarding the pathogenicity of S. sciuri to animals. From the pericardial fluid of a diseased piglet with exudative epidermitis (EE), we isolated a strain of Staphylococcus in pure culture. Surprisingly, this isolate was a member of S. sciuri rather than S. hyicus as identified by its biochemical traits and also by analysis of 23S ribosomal DNA using Internal Transcribed Spacer PCR. In addition, inoculation of newborn piglets with 1x10(10) CFU of the isolate by oral feeding or intra-muscular injection successfully reproduced EE in piglets, which suggested that the oral intake of the pathogen by the animals is one of the major routes of exposure. These unexpected findings prioritized S. sciuri as important zoonotic agents, which may have ramifications for human medicine.

Biofilm formation in medical device-related infection

Medical device-associated infections, most frequently caused by coagulase-negative staphylococci, especially Staphylococcus epidermidis, are of increasing importance in modern medicine. Regularly, antimicrobial therapy fails without removal of the implanted device. The most important factor in the pathogenesis of medical device-associated staphylococcal infections is the formation of adherent, multilayered bacterial biofilms. There is urgent need for an increased understanding of the functional factors involved in biofilm formation, the regulation of their expression, and the interaction of those potential virulence factors in device related infection with the host. Significant progress has been made in recent years which may ultimately lead to new rational approaches for better preventive, therapeutic, and diagnostic measures.

Enterococcus durans endocarditis in a patient with transposition of the great vessels

A case of native valve endocarditis caused by Enterococcus durans in a patient with transposition of the great vessels is reported. The patient was treated initially with gentamicin and ceftriaxone; after isolation of enterococci, ceftriaxone was switched to ampicillin. The only virulence factors established in the strain were haemolytic activity and biofilm formation.