[Multiple hyperplastic colon polyps in a cow]. / Multiple hyperplastische Kolonpolypen bei einem Rind.

INTRODUCTION: Reports on bovine colon polyps are rare. The present report demonstrates macro- and microscopically hyperplastic colon polyps of a seven-year-old German Simmental cow. Differential diagnoses (adenoma and adenocarcinoma) and aetiology are discussed. Even in cattle, intestinal polyps should be considered as a cause of intussusception.

INTRODUCTION: Les rapports concernant des polypes du colon chez les bovins sont rares. Le présent rapport fait état de polypes du côlon macro- et microscopiquement hyperplasiques chez une vache Simmental allemande de sept ans. Les diagnostics différentiels (adénome et adénocarcinome) et l'étiologie sont discutés. Même chez les bovins, les polypes intestinaux doivent être considérés comme une cause d'invagination.

Effect of xylazine administration before laparoscopic abomasopexy to correct left displaced abomasum on markers of stress in dairy cows.

Left displacement of the abomasum in dairy cows is a disease diagnosed all over the world. In Germany, a common method for its correction is laparoscopic abomasopexy (LA). The aim of the study was to assess cortisol and substance P concentrations, behavioral patterns, and feeding and rumination times during and after LA in cattle treated with xylazine before LA compared with nonsedated cattle. A total of 28 cattle that had been referred to a veterinary teaching hospital with a diagnosis of left displacement of the abomasum were randomly assigned to 1 of 2 groups. Surgery was performed according to a standardized protocol. Animals of XYL (n = 14) received xylazine (0.02 mg/kg body weight i.v.) before surgery, and animals of CON (n = 14) received a placebo (0.9% saline i.v.). All cows received ketoprofen (3 mg/kg body weight i.v.) twice, and benzyl penicillin procaine (20,000 IU/kg body weight i.m.) for 5 ± 1 d. Blood samples for the determination of plasma cortisol concentration (PCC) and plasma substance P concentration were taken 3 h before surgery (+00:00), at 1100 h (+03:00), 1115 h (+03:15, skin incision), 1130 h (+03:30), 1145 h (+03:45, dorsal recumbency), 1200 h (+04:00, end of surgery), 1230 h (+04:30), 1300 h (+05:00), 1400 h (+06:00), and 1100 h (+27:00) the following day. Behavior was assessed on the day of surgery and the following day (0800, 1300, and 1700 h), and during surgery. Feeding and rumination time were recorded for 24 h after surgery. Data analysis was done using R (R Foundation for Statistical Computing, Vienna, Austria). The LA was performed in all animals without negative effects. The PCC was lower in XYL than in CON at all times and significantly lower at +03:30. In CON, PCC was significantly higher at +03:45, +04:00, and +04:30 compared with +03:00. In XYL, PCC was significantly lower at +03:15 and +03:30 compared with +03:00, and significantly higher at +04:00 and +04:30. Plasma substance P concentration did not differ between groups. No differences were observed in behavior between CON and XYL. Feeding and rumination times did not differ between groups. Animals in XYL showed significantly more chews per bolus after surgery than animals in CON. In conclusion, administration of xylazine before LA results in lower stress levels for cattle during the course of LA, especially before being put into lateral and dorsal recumbency. Therefore, in the opinion of the authors, xylazine administration can be recommended before LA to improve the well-being of the animals during and after surgery.

[Long bone fractures in cattle: A retrospective study of treatment and outcome in 194 cases]. / Frakturen der langen Röhrenknochen beim Rind: Eine retrospektive ­Auswertung der Therapie und des Verlaufs bei 194 Tieren.

INTRODUCTION: The present retrospective study investigated the localization, cause, treatment and healing of long bone fractures in cattle. Over a period of ten years, medical records of 194 cattle of all ages with a long bone fracture, presented at the Clinic for Ruminants with Ambulatory and Herd Health Services at LMU Munich, were evaluated. The majority of patients (n = 131, 67.5%) were younger than two weeks of age. Of these, 118 calves sustained the fracture on the day of birth (60.8%). An obstetrical assistance was found in 57.4% (n = 58) of birth-related cases as a fracture cause. The femur was most frequently affected in calves aged up to two weeks (n = 35; 26.7%). The second most frequent fractures occurred in the metacarpus (n = 31; 22.9%) in this age group, followed by metatarsus (n = 28; 21.4%) and tibia (n = 27; 20.6%). Fractures of the antebrachium (n = 9; 6.9%) and the humerus were rare (n = 1; 0.8%). A total of 194 patients were diagnosed with 50 femur fractures (25.8%), 53 metacarpal fractures (27.3%), 43 metatarsal fractures (22.2%), 30 tibial fractures (15.5%), 11 antebrachial fractures (5.7%) and 7 humeral fractures (3.6%). Of the 194 animals, 78 (40.2%) had to be euthanized, 42 of them (53.8%) without treatment. In 150 patients, treatment was initiated, of which 110 patients (73.3%) were dismissed healthy from the clinic. Among the conservative treatment methods were stall rest, casts, casts combined with a U-shaped metal rail (walking casts) and the Thomas splint. Surgical therapy (internal fixation with plates or screws, transfixation pin casts) was used to treat 65 animals (33.5%). While 86.9% (74 out of 85) of the conservatively treated animals left the clinic alive, it were only 58.1% (36 out of 65) animals after surgical treatment. In the newborn calves, colostrum supply had a significant effect on the success of the treatment. If the gamma-glutamyl transferase concentration was below 200 IU/L in the calves aged under 4 days, the healing rate was significantly different from the cure rate of sufficiently immunized patients (26.9% (7 out of 26) vs. 65.3% (47 out of 72), P = 0.001).

INTRODUCTION: La présente étude rétrospective a examiné la localisation, la cause, le traitement et la guérison des fractures des os longs chez les bovins. Sur une période de dix ans, les dossiers médicaux de 194 bovins de tous âges souffrant d'une fracture d'un os long et présentés à la Clinique pour les ruminants avec services ambulatoires et services de santé du troupeau à la Ludwig-Maximilians-Universität de Munich, ont été évalués. La majorité des patients (n = 131, 67,5%) étaient âgés de moins de deux semaines. Parmi ceux-ci, 118 veaux ont subi la fracture le jour de leur naissance (60,8%). Une assistance obstétricale par traction a été trouvée dans 57,4% (n = 58) des cas liés à la naissance en tant que cause de fracture. Le fémur était le plus souvent touché chez les veaux âgés de moins de deux semaines (n = 35; 26,7%).). La deuxième fracture la plus fréquente survenait au niveau du métacarpe (n = 31; 22,9%)), suivi du métatarse (n = 28; 21,4%) et du tibia (n = 27; 20,6%).). Les fractures de l'antebrachium (n = 9; 6,9%) et de l'humérus étaient rares (n = 1; 0,8%). Au total, sur les 194 patients ont a diagnostiqué 50 fractures du fémur (25,8%), 53 fractures du métacarpe (27,3%), 43 fractures du métatarse (22,2%), 30 fractures du tibia (15,5%), 11 fractures antébrachiales (5,7%) et 7 fractures de l'humérus (3,6%). Sur les 194 animaux, 78 (40,2%) ont dû être euthanasiés, dont 42 (53,8%) sans traitement. Deux animaux (1.0%) ont été abattus. Sur les 150 patients traités, 36 (24.0%) ont été euthanasiés et 4 ont péri. 110 patients (73,3%) ont été renvoyés en bonne santé de la clinique. Parmi les méthodes de traitement conservatif figurent le repos en stalle, les plâtres en résine, les plâtres en résine combinés à une attelle en métal en forme de U comme attelle de marche et l'attelle de Thomas. Un traitement chirurgical (fixation interne à l'aide de plaques et/ou de vis de traction, broches de transfixion avec pont en matière synthétique) a été utilisé pour traiter 65 animaux (33,5%). Alors que 86,9% (74 sur 85) des animaux traités de manière conservatrice ont quitté la clinique en vie, ce ne sont que 58,1% (36 sur 65) des animaux après traitement chirurgical. Chez les veaux nouveau-nés, l'apport de colostrum a eu un effet significatif sur le succès du traitement. Si la concentration de gamma-glutamyl transférase était inférieure à 200 UI / L chez les veaux âgés de moins de 4 jours, le taux de guérison était significativement différent du taux de guérison de patients suffisamment immunisés (26,9% (7 sur 26) contre 65,3% (47 sur 72), p = 0,001).

[Possibilities of diagnostics in unilateral fibular-nerve-paresis in a calf]. / Möglichkeiten der Diagnostik bei einseitiger N.-fibularis-Parese beim Kalb.

INTRODUCTION: The present case report describes the workup of unilateral fibular-nerve-paresis in a female neonatal Fleckvieh calf. The calf was admitted to the Clinic for Ruminants with Ambulatory and Herd Health Services, Ludwig- Maximilians-University Munich as part of an investigation into a herd problem. The herd problem was presented as movement disorder in neonatal calves with an incidence of 10%. A physical, hematological, and musculoskeletal, as well as neurological examination was performed, and a diagnosis of a left-sided paresis of the fibular-nerve (N. fibularis) was made. Further special examinations including sonography, magnetic resonance tomography and muscle, lymph node, and nerve biopsies of the affected limb of the calf were also carried out. Advanced imaging examinations suggested the presence of inflammatory changes caudal to the left stifle joint in the region of the fibular nerve. Histopathological examination of the nerve biopsy confirmed the presence of a fibular-nerve-neuritis. Inflammatory changes in the ischiocrural-muscles were most likely injection-induced, consistent with the history of the veterinary practitioner and the examination results.

A Hexanuclear Iron(II) Layer with Two Square-Planar FeO4 Units Spanned by Tetrasiloxide Ligands: Mimicking of Minerals and Catalysts.

A hexanuclear iron(II) siloxide complex has been prepared by reacting an incompletely condensed silsesquioxane first with NaOMe and then with Fe(OTf)2. In the process of product formation, the siloxane framework undergoes a transformation and it was shown that this happens already upon addition of base: Treatment of the ligand precursor with NaOMe leads to a completely condensed silsesquioxane cage with 12 Si atoms that is composed of 2 equiv of the tetrasiloxide ligands found in the product complex. Its iron centers form a two-dimensional array reminiscent of the situations found in minerals and two-dimensional oxide films caused by segregation of FeOx and silica. As the hexairon(II) assembly contains two high-spin square-planar FeO4 units-suggested to represent the active sites in Fe-zeolites, which react with N2O to generate strongly oxidizing sites-it was treated with Me3NO. This led to the oxidation of two of the iron centers to the oxidation state +III and elimination of one iron ion, so that a pentanuclear, mixed valent iron siloxide was formed. All complexes were fully characterized.

Hypoglycaemia in hospitalised neonatal calves: Prevalence, associated conditions and impact on prognosis.

Hypoglycaemia has traditionally been associated with neonatal diarrhoea and endotoxaemia in calves, but the clinical relevance of this finding in spontaneously diseased calves has not previously been evaluated. To determine the prevalence and prognostic relevance of severe hypoglycaemia (plasma glucose concentration < 2 mmol/L), data from 10,060 hospitalised calves (≤21 days of age) were retrospectively analysed. Additionally, clinical findings and diagnoses in a subset of 100 calves with severe hypoglycaemia were compared with those in 100 randomly selected calves with initial plasma glucose concentrations in the reference range (4.4-6.9 mmol/L). The prevalence of severe hypoglycaemia in the whole study sample was 6.3%. Severe hypoglycaemia was associated with a poor survival rate of 20.6% vs. 74.0% discharged animals in the group of calves with initial normoglycaemia. Review of medical records revealed that severe hypoglycaemia was significantly associated with clinical or necropsy evidence of septicaemia, hypothermia, history or clinical evidence of malnutrition, and peritonitis of varied origin, but not with the presence of neonatal diarrhoea. Only 10 of 100 calves with severe hypoglycaemia showed central nervous involvement such as seizures and opisthotonus. In conclusion, severe hypoglycaemia has a low prevalence in diseased calves in a hospital setting, but is associated with serious health problems and therefore a high risk of non-survival. Severe hypoglycaemia was not easily diagnosed based on clinical signs, but should be suspected in calves with clinical evidence of septicaemia, hypothermia, acute abdominal emergencies, and a history or clinical evidence of malnutrition.

Balling gun-induced trauma in cattle: clinical presentation, diagnosis and prevention.

Pharyngeal trauma in cattle can occur during the administration of oral medication using a balling gun. The number of cases of severe complications due to bolus application that have been referred to our hospital has increased from nil between 1996 and 2008 to three or four per year. In our experience, reports by bovine veterinarians of patients with severe and often fatal pharyngeal trauma, which were not referred to the clinic, have become more common in recent years as well. The incidence of this complication is likely to be higher than this number of referrals suggests. Diagnosis without the help of imaging techniques, such as radiography and endoscopy, may be difficult, especially in cases where exploration of the pharynx cannot be carried out, or is unable to confirm the absence or presence of a lesion. Prognosis is often poor in cases where perforation has been confirmed. Boluses are increasingly administered by the owners or farm personnel without the supervision of a veterinarian. In order to prevent losses due to balling gun-induced injuries, the veterinarian plays a crucial role in giving advice to his clients. Five cases of cattle suffering from varying degrees of balling gun-induced trauma are presented, and consideration is given to incorrect application techniques.

Preparation and stabilization of aluminium trifluoroacetate fluoride sols for optical coatings.

For the first time, aluminium fluorides in liquid phase are available for optical applications. By modifying the conditions of the fluorolytic sol-gel synthesis of aluminium fluorides transparent sols with low viscosities were obtained. These sols consist mainly of small oligomeric or cluster units of aluminium fluoride which are not measurable by DLS, WAXS, SAXS and show unusual narrow signals in solid state NMR. Isolated particles with diameters up to five nanometers can be identified by TEM measurements and allow the use of their sols in optical and anti reflecting coatings. The sol particles were modified by trifluoroacetic acid to prevent agglomeration, and as a result, the obtained xerogels can be re-dispersed transparently in organic solvents.

Metabolic acidosis in neonatal calf diarrhea-clinical findings and theoretical assessment of a simple treatment protocol.

BACKGROUND: Clinical assessment of metabolic acidosis in calves with neonatal diarrhea can be difficult because increased blood concentrations of d-lactate and not acidemia per se are responsible for most of the clinical signs exhibited by these animals. OBJECTIVES: To describe the correlation between clinical and laboratory findings and d-lactate concentrations. Furthermore, the theoretical outcome of a simplified treatment protocol based on posture/ability to stand and degree of dehydration was evaluated. ANIMALS: A total of 121 calves with diagnosis of neonatal diarrhea admitted to a veterinary teaching hospital during an 8-month study period. METHODS: Prospective blinded cohort study. Physical examinations were carried out following a standardized protocol. Theoretical outcome of treatment was calculated. RESULTS: Type and degree of metabolic acidosis were age dependent. The clinical parameters posture, behavior, and palpebral reflex were closely correlated to base excess (r = 0.74, 0.78, 0.68; P < .001) and d-lactate concentrations (r = 0.59, 0.59, 0.71; P < .001), respectively. Thus, determining the degree of loss of the palpebral reflex was identified as the best clinical tool for diagnosing increase in serum d-lactate concentrations. Theoretical outcome of treatment revealed that the tested dosages of sodium bicarbonate are more likely to overdose than to underdose calves with diarrhea and metabolic acidosis. CONCLUSIONS AND CLINICAL IMPORTANCE: The degree of metabolic acidosis in diarrheic calves can be predicted based on clinical findings. The assessed protocol provides a useful tool to determine bicarbonate requirements, but a revision is necessary for calves with ability to stand and marked metabolic acidosis.

[Treatment of long bone fractures in 125 newborn calves. A retrospective study]. / Behandlung von Frakturen der langen Röhrenknochen bei 125 neugeborenen Kälbern. Eine retrospektive Untersuchung.

OBJECTIVES: Retrospective study of the causes, location, configuration, treatment and outcome of long bone fractures in newborn calves. MATERIAL AND METHODS: The medical records of 125 calves presented during a 16-year period because of fracture of the humerus (3 calves), radius/ulna (14), femur (50) or tibia (58) were evaluated. The majority of calves (61.6%) sustained the fractures during assisted delivery. Of 125 calves, 107 were treated and 18 were euthanized because of concurrent diseases. Conservative treatment was used in 16 calves and surgical treatment in 91. Four of the latter were euthanized because of muscle contraction which prevented fracture reduction, and five others died in surgery. RESULTS: Fracture healing occurred after conservative treatment in 10 of 16 calves and after surgical treatment in 44 of 82 calves. The outcome was better in calves with plate and clamp-rod internal fixation (37/58 healed) than with intramedullary pinning (4/16 healed) or external fixation (3/8 healed). There were significant associations (chi2-test, p<0.01) between concurrent diseases and choice of therapy and fracture healing. Of 67 calves that developed complications, only 26 could be cured. Common complications were implant loosening and instability, which were often followed by osteomyelitis and sepsis. Implants were removed in 39 of 44 surgically treated calves that survived up to 6 months postoperatively. Long-term follow up (> 6 months postoperatively) by clinical and radiographic re-examination (25 calves) or telephone inquiry (29 calves) revealed that 54 animals were sound and had returned to their intended use. CONCLUSIONS AND CLINICAL RELEVANCE: The treatment of long bone fractures in newborn calves remains difficult because of a high incidence of complications. These are most likely attributable to trauma during delivery, which results in insufficient colostrum intake and predisposes to concurrent diseases. In addition, the characteristics of juvenile bones do not provide sufficient physical strength for implants. Therefore, professional and diligent assistance during forced extraction, particularly in presentations with "stifle lock" or "hip lock", is required to minimize the incidence of long bone fractures in newborn calves. Most cases require surgical fixation, which is time consuming, expensive and carries a guarded prognosis.

A case of congenital unilateral hip dysplasia in a newborn calf.

We describe the case of a Simmental calf with congenital unilateral hip dysplasia. In the initial physical exam, the calf was able to stand unsteady when helped and showed severe swinging lameness in the left hind limb. Unilateral hip laxity and a positive Ortolani sign indicated subluxation of the femur within the hip joint. This finding was further confirmed by radiographic examination which also showed malformation of the left femoral head and acetabulum. After a short period of clinical improvement the calf's health deteriorated and it was euthanized due to signs of severe coxarthrosis. Pathological examination of the affected hip joint revealed a severe acetabular and femoral dysplasia with an incomplete formation of the epiphysis of the femoral head and a chronic granulating coxarthritis without evidence of primary infectious events.

Real-time PCR method for Salmonella spp. targeting the stn gene.

AIM: To develop a real-time PCR assay for Salmonella spp. targeting the stn gene. METHODS AND RESULTS: The presence of stn in the Salmonella bongori genome was found by a BLAST with Salmonella enterica stn sequence. Manual alignment of stn sequences showed that Salm. bongori had 88% sequence identity with Salm. enterica. Two primers (stnL-433 and stnR-561) and a probe (stnP-452) were designed to target conserved regions in stn and meet the requirements of a 5'-nuclease assay. The primers and probe were evaluated against 353 isolates, including 255 Salm. enterica representing 158 serotypes, 14 Salm. bongori representing 12 serotypes and 84 non-Salmonella representing 56 species from 31 genera. All isolates were correctly identified, with the exception of three isolates of Citrobacter amalonaticus, which gave false positives. The limit of detection with cultured Salmonella was 3 CFU per reaction. CONCLUSIONS: The stn real-time PCR method had 100% inclusivity, 96.4% exclusivity and a level of detection of 3 CFU per reaction for cultured Salmonella spp. SIGNIFICANCE AND IMPACT OF THE STUDY: The study showed that stn is present in Salm. bongori and is a valid target for both species of Salmonella. The Salmonella s tn real-time PCR is a useful method for identifying Salmonella spp.

Altered levels of high-energy phosphate compounds in fibroblasts from different forms of neuronal ceroid lipofuscinoses: further evidence for mitochondrial involvement.

The pathogenesis of neurodegeneration in neuronal ceroid lipofuscinosis (NCL) is still not clear despite progress in mutation analysis of these diseases. We have recently observed anomalies at the level of the mitochondrial ATPsynthase (complex V of the respiratory chain) in fibroblasts from children with CLN1, CLN2, CLN3 and in an ovine model (OCL6). The measurements were carried out in vitro. If these alterations were of relevance in vivo as well, contents of high-energy phosphate compounds should be reduced. In the present study, we measured levels of creatine phosphate (CP), ATP, ADP and AMP in fibroblasts from children with CLN1, CLN2, CLN3 and in OCL6. ATP was reduced to about 50% of normal in CLN1, CLN2 and CLN3, ADP was about 30% of normal in these cells, and CP was 50% of normal in CLN1 and CLN2 but remained normal in CLN3. In fibroblasts of NCL-sheep, however, CP and ADP were increased to 690% and 220% of normal, respectively, while ATP remained normal. If the anomalies found in cellular energy metabolism in fibroblasts were expressed in neurons from NCL patients and NCL sheep 'slow-onset excitotoxicity' could occur leading to cellular dysfunction and eventually to cell death.

Osteochondrosis and epiphyseal bone abnormalities associated with copper deficiency in bison calves.

Two bison calves were submitted to the Western College of Veterinary Medicine to confirm suspected copper deficiency. In addition to clinical signs, there were pathologic changes in the cartilage and subchondral bone of several joints. Water analysis indicated high levels of sulfate in the drinking water, contributing to a secondary copper deficiency.

The antidepressant response to tricyclics in major depressives is accelerated with adjunctive use of methylphenidate.

Standard tricyclic antidepressant (TCA) treatment usually entails response latencies of 2 to 4 weeks. To accelerate the antidepressant response, methylphenidate (MPH) was administered together with standard antidepressants in an open label trial. Twenty inpatients (9 females, 11 males) met DSM-III-R criteria for major depressive episode (15 unipolar and 2 bipolar), depression NOS (n = 2), or Research Diagnostic Criteria for schizoaffective illness, depressed type (n = 1). Following evaluation for depression, patients received an open-label oral MPH stimulation trial (MST), in 1 or 2 dosages of 5 to 15 mg at 0900 and 1000 hours. Twenty patients with positive MST response were treated with TCAs combined with MPH (5-15 mg/d). Therapeutic response was defined as 50 percent decline in the Hamilton Rating Scale for Depression. Six of 20 (30%) patients responded after 1 week of combination TCA-MPH, and 10 of 16 (63%) after 2 weeks. Adverse effects of the combination treatment included: dizziness and orthostatic blood pressure changes (n = 3), dry mouth (n = 3), increased anxiety (n = 3), and hypomania (n = 1). The severity of adverse effects required cessation of the MPH in 3 patients. Elevated self-ratings of anxiety were associated with lack of improvement after both 1 and 2 weeks. Adjunctive MPH appears to accelerate response to tricyclics in this systematically conducted open trial, and adverse effects of the TCA-MPH combination were usually tolerable. Positive response on the MST may be predictive of beneficial therapeutic outcome, especially in depressed patients without high anxiety levels.(ABSTRACT TRUNCATED AT 250 WORDS)

[Potential cardiotonics. 15. Crystal modifications of 3-cyano-2-morpholino-5-(4-pyridinyl)pyridine (AWD 122-14)]. / Potentielle Kardiotonika. 15. Mitteilung: Kristallmodifikationen von 3-Cyan-2-morpholino-5-(pyrid-4-yl)pyridin (AWD 122-14).

The preparation and X-ray crystallographic characterisation of 10 polymorphic or pseudo-polymorphic forms of the novel cardiotonic AWD 122-14 are described. Thermic transformations of some polymorphic forms into the alpha-form was proved by thermogravimetric analysis and powder diffraction pattern. In dissolution behaviour no significant differences were found between the crystalline modifications but with regard to galenic processing compact alpha-, gamma- and epsilon-forms show advantages.

Virulent gentamicin-induced small colony variants of Staphylococcus aureus.

Stable nonhemolytic small colony variants were isolated in pure culture from nine of 30 Staphylococcus aureus clinical strains after incubation of log10 7.0 cfu for 48 hr in MH broth containing 1.0 microgram/ml gentamicin. The variants resembled Staphylococcus epidermidis on blood agar, but they were positive for tube coagulase and thermostable nuclease at 24 hr and fermented mannitol slowly. The infectivity and virulence of four variants were compared to four parent S. aureus and three S. epidermidis strains in a rabbit model of endocarditis. Log10 5.0 cfu of the variant S. aureus, parent S. aureus, or S. epidermidis strains were injected intravenously into rabbits with intracardiac catheters. Quantitative culture of vegetations demonstrated endocardial infection in 47 of 49 (96%) animals injected with S. aureus variants, 44 of 44 injected with S. aureus parent strains, and four of 21 (19%) S. epidermidis-injected animals. The mortality rate in untreated animals within 4 days was five of 49 (10%) for variant S. aureus, 33 of 44 (75%) for parent S. aureus, and 0 of 21 for S. epidermidis. Small colony variants of S. aureus may be mistaken for S. epidermidis, but the variants are significantly more infective than S. epidermidis and are more likely to cause endocarditis. Gentamicin-induced S. aureus small colony variants are as infective but less virulent than their parent S. aureus strains.