Resistance to fluoroquinolones and methicillin in ophthalmic isolates of Staphylococcus pseudintermedius from companion animals.

Resistance to fluoroquinolones and methicillin was determined for 49 ophthalmic isolates of Staphylococcus pseudintermedius from dogs with and without ophthalmic disease. Resistance was observed for ciprofloxacin (40.8%), ofloxacin (38.8%), enrofloxacin (38.8%), levofloxacin (34.7%), and moxifloxacin (4.1%). Eighteen isolates, 16 of which were resistant to oxacillin, were mecA-positive. Nine of the 16 oxacillin-resistant mecA-positive S. pseudintermedius isolates were resistant to more than one fluoroquinolone and 2 isolates were resistant to 5 fluoroquinolones. The frequency of mecA gene occurrence and fluoroquinolone resistance was twice as high among S. pseudintermedius isolates derived from dogs with ophthalmic disease compared with isolates for dogs without ophthalmic disease. The high prevalence of methicillin and fluoroquinolone resistance in S. pseudintermedius from dogs with ophthalmic disease is a concern.

Résistance aux fluoroquinolones et à la méthicilline dans les isolats oculaires deStaphylococcus pseudintermediusdes animaux de compagnie. La résistance aux fluoroquinolones et à la méthicilline a été déterminée pour 49 isolats oculaires de Staphylococcus pseudintermedius provenant de chiens atteints et exempts d'une maladie ophtalmique. La résistance a été observée pour la ciprofloxacine (40,8 %), l'ofloxacine (38,8 %), l'enrofloxacine (38,8 %), la levofloxacine (34,7 %) et la moxifloxacine (4,1 %). Dix-huit isolats, dont 16 étaient résistants à l'oxacilline, étaient positifs pour mecA. Neuf des 16 isolats de S. pseudintermedius positifs pour mecA résistants à l'oxacilline et étaient résistants à plus d'une fluoroquinolone et 2 isolats étaient résistants à 5 fluoroquinolones. La fréquence de l'occurrence du gène mecA et de la résistance aux fluoroquinolones était deux fois supérieure pour les isolats S. pseudintermedius dérivés de chiens atteints d'une maladie ophtalmique comparativement aux chiens sans maladie ophtalmique. La prévalence élevée de la résistance à la méthicilline et à la fluoroquinolone pour S. pseudintermedius chez les chiens atteints d'une maladie ophtalmique est préoccupante.(Traduit par Isabelle Vallières).

Antibiotic resistance and molecular characterization of ophthalmic Staphylococcus pseudintermedius isolates from dogs.

The prevalence, virulence potential, and antibiotic resistance of ophthalmic Staphylococcus pseudintermedius (SP) isolated from dogs were examined. Sixty-seven Staphylococcus species were isolated from ophthalmic samples and surveyed for species-specific sequences in the Staphylococcus intermedius group (SIG) nuclease gene (SInuc), exfoliative toxin gene for SIG (siet), and antibiotic resistance genes (blaZ and mecA). PCR-restriction fragment length polymorphism analysis of the pta gene was also performed. Fifty isolates were identified as SIG strains, all of which were found to be SP. The blaZ gene was detected in 42 of the 50 SP strains and mecA gene was observed in 18 of the 50 SP strains. The 50 SP strains were most susceptible to amoxicillin/clavulanic acid (94%) and chlorampenicol (70%), and highly resistant to tetracycline (94%) and penicillin (92%). It was also found that 16 (88.9%) mecA-positive SP strains were resistant to oxacillin, tetracycline and penicillin. All mecA-positive SP were resistant to more than four of the eight tested antibiotics and therefore considered SP with multi-drug resistance (MDR). Our results indicate a high prevalence of antibiotic resistance genes in ophthalmic SP along with a close relationship between MDR SP strains and the mecA gene. Based on our findings, judicious administration of antibiotics to companion dogs is necessary.

Gross morphological features of the organ surface primo-vascular system revealed by hemacolor staining.

The primo-vascular system (PVS), which consists of primo-vessels (PVs) and primo-nodes (PNs), is a novel thread-like structure identified in many animal species. Various observational methods have been used to clarify its anatomical properties. Here, we used Hemacolor staining to examine the gross morphology of organ-surface PVS in rats. We observed a sinus structure (20-50 µ m) with a remarkably low cellularity within PNs and PVs and several lines of ductules (3-5 µ m) filled with single cells or granules (~1 µ m) in PV. Both sinuses and ductules were linearly aligned along the longitudinal axis of the PVS. Such morphology of the PVS was further confirmed by acridine orange staining. In PN slices, there was a honeycomb-like structure containing the granules with pentagonal lumens (~10 µ m). Both PVs and PNs were densely filled with WBCs, RBCs, and putative mast cells (MCs), which were 90.3%, 5.9%, and 3.8% of the cell population, respectively. Granules in putative MCs showed spontaneous vibrating movements. In conclusion, the results show that Hemacolor, a simple and rapid staining system, can reveal the gross morphological features reported previously. Our findings may help to elucidate the structure and function of the PVS in normal and disease states in future studies.

Relation between poststenting peristent plaque components and late stent malapposition after drug-eluting stent implantation: virtual histology-intravascular ultrasound analysis.

BACKGROUND: Impact of plaque composition on late stent malapposition (LSM) after drug-eluting stent (DES) implantation has not been evaluated. METHODS: We evaluated the relation between plaque components at poststenting peristent area (between external elastic membrane and stent areas) and LSM after DES implantation in 266 patients (314 native lesions; paclitaxel-eluting stent in 205 lesions, sirolimus-eluting stent in 66 lesions, zotarolimus-eluting stent in 32 lesions and everolimus-eluting stent in 11 lesions) in whom virtual-histology intravascular ultrasound was performed at index (poststenting) and follow-up (mean: 11.7 ± 4.8 months). RESULTS: LSM occurred in 24 patients with 30 lesions (9.6%) and there were no significant differences in the incidences of LSM among 4 DES groups [21/205 (10.2%) in paclitaxel-eluting stent, 6/66 (9.1%) in sirolimus-eluting stent, 2/32 (6.3%) in zotarolimus-eluting stent and 1/11 (9.1%) in everolimus-eluting stent, p=0.5)]. Patients with LSM were presented with more acute myocardial infarction (50% vs. 28%, p=0.026) and were more diabetics (50% vs. 30%, p=0.030) compared with those without LSM. Lesions with LSM had more poststenting peristent %necrotic core (NC) volume compared with those without LSM (25.8 ± 11.1% vs. 21.0 ± 5.7%, p<0.001). Independent predictors of LSM were poststenting peristent %NC volume [odds ratio (OR); 1.216, 95% CI; 1.053-1.405, p=0.008], acute myocardial infarction (OR; 2.897, 95% CI; 1.675-4.118, p=0.029), and diabetes mellitus (OR; 2.413, 95% CI; 1.543-3.996, p=0.038). CONCLUSIONS: Poststenting peristent NC component especially in patients with acute myocardial infarction and in those with diabetes mellitus is associated with the development of LSM after DES implantation.

The Number of Endothelial Progenitor Cells is Decreased in Patients With Non-Dipper Hypertension.

BACKGROUND AND OBJECTIVES: Circulating endothelial progenitor cells (EPCs) play a key role in the maintenance of endothelial homeostasis and promote vascular repair. A reduced number of EPCs and the functional activity have been associated with several cardiovascular risk factors. However, the relationship between the number of EPCs and circadian rhythm of the blood pressure (BP) remains unclear. The purpose of the present study was to evaluate the relationship between the circadian rhythm of the BP and EPCs in patients with essential hypertension. SUBJECTS AND METHODS: A total of 45 patients with essential hypertension who were newly identified by outpatient BP measurements, underwent 24-hour ambulatory BP monitoring. Among the 45 patients with essential hypertension, 20 were classified as dippers (12 men and 8 women; mean age 48±14 years) and 25 as non-dippers (14 men and 11 women; mean age 52±18 years). The EPC count was isolated from the peripheral bloodstream and quantified by flow cytometry. RESULTS: The baseline clinical characteristics were similar between the dipper and non-dipper hypertensive patients. The circulating EPCs were statistically reduced in the non-dipper patients as compared to the dippers (104±60 vs. 66±47 EPCs per 106 mononuclear cells, p=0.027). The circulating EPC level correlated positively with the circadian changes in the systolic and diastolic BP (r=0.435, p=0.003, and r=0.310, p=0.038, respectively). CONCLUSION: The present study demonstrated that the EPC count was reduced in the peripheral bloodstream in non-dipper hypertensive patients.

In vivo cell tracking of canine allogenic mesenchymal stem cells administration via renal arterial catheterization and physiopathological effects on the kidney in two healthy dogs.

Stem cell therapy is being special premise for various renal diseases. However, there is limited literature on localization and pathologic and functional effects of allogenic mesenchymal stem cells (MSCs) in healthy dogs. Two healthy dogs were included in this study. Canine MSCs (cMSCs) were cultured from canine bone marrow and incubated with superparamagnetic iron oxide (SPIO) for in vivo cell tracking via MR imaging. The dogs were given the MSC (3 × 10(6) cells) into a renal artery via femoral artery catheterization. Follow-up serial renal assessments included ultrasonography and MRI, serum chemistry, urine analysis, and renal clearance tests. The dogs were euthanized at days 8 and 35 respectively for histopathologic evaluation of kidney. Strong hypointensity in MRI was detected in the treated renal cortex the day after cMSCs infusion. However they disappeared from MR image by the 8th day. Of the serum chemistry tests, serum hepatic enzymes (ALT, AST) were significantly elevated for one week after cMSCs treatment. Histopathological findings also revealed infiltration of SPIO-containing cells into the parenchyma of kidney. On 35th day, histopathology, glomerular atrophy, tubular necrosis, and mineralization were found in the subcapsular cortex, with fibrosis of the interstitial tissues. In vivo MRI studies of stem cells were useful in determining the sequential location of stem cells in the renal parenchyma of healthy dogs. Allogenic stem cells administered via renal artery caused inflammation, tubular necrosis, mineralization, and fibrosis without functional complications.

High prevalence of Fluoroquinolone- and Methicillin-resistant Staphylococcus pseudintermedius isolates from canine pyoderma and otitis externa in veterinary teaching hospital.

Recently, a total of 74 Staphylococcus pseudintermedius isolates were collected from clinical cases of canine pyoderma and otitis externa in Korea. In this study, we examined in vitro fluoroquinolone resistance among those isolates using a standard disk diffusion technique. The results demonstrated that approximately 18.9% to 27.0% of the isolates possessed bacterial resistance to both veterinary- and human-licensed fluoroquinolones except one isolate, including moxifloxacin (18.9% resistance), levofloxacin (20.3% resistance), ofloxacin (24.3% resistance), ciprofloxacin (25.7% resistance), and enrofloxacin (27.0% resistance). Most surprisingly, 14 out of 74 (18.9%) isolates were resistant to all the five fluoroquinolones evaluated. Moreover, a PCR detection of the methicillin resistance gene (mecA) among the 74 isolates revealed that 13 out of 25 (52.0%) mecA-positive isolates, but only 7 out of 49 (14.3%) mecA-negative isolates, were resistant to one or more fluoroquinones. Taken together, our results imply that bacterial resistance to both veterinary- and human-use fluoroquinolones becomes prevalent among the S. pseudintermedius isolates from canine pyoderma and otitis externa in Korea as well as that the high prevalence of the mecA-positive S. pseudintermedius isolates carrying multiple fluoroquinolone resistance could be a potential public health problem.

Prevalence of genes for enterotoxins, toxic shock syndrome toxin 1 and exfoliative toxin among clinical isolates of Staphylococcus pseudintermedius from canine origin.

A total of 74 Staphylococcus pseudintermedius strains were isolated from the 99 clinical cases of canine pyoderma or chronic otitis in our veterinary teaching hospital during May 2006-February 2008. In this study, we examined the genetic distribution of staphylococcal pyogenic toxins such as staphylococcal enterotoxins A (sea), B (seb), C (sec), D (sed), E (see), and toxic shock syndrome toxin 1 (tst) as well as the previously characterized S. intermedius exfoliative toxin (siet) among those isolates. The polymerase chain reaction analyses with the toxin gene-specific primers revealed that 18 (24.3%) of 74 S. pseudintermedius isolates carried the sec genes, but none of the sea, seb, sed, see and tst genes. Further DNA sequencing analysis of the amplified sec genes revealed that they all belonged to the canine type C staphylococcal enterotoxin (SEC(canine) ) whose superantigenic activity has been demonstrated. In addition to the sec(canine) genes, our polymerase chain reaction results showed that all the 74 isolates carried the siet gene. Since both SEC(canine) and SIET toxins are known to be biologically active, it would be interesting to investigate how those toxins are involved in the pathogenesis of the canine diseases by S. pseudintermedius such as pyoderma or chronic otitis.

Antibiotic resistance profiles of Staphylococcus pseudintermedius isolates from canine patients in Korea.

In this study, the prevalence of antibiotic resistance was examined among 74 Staphylococcus pseudintermedius strains recently isolated from clinical cases of canine pyoderma and otitis externa at the veterinary teaching hospital at Konkuk University, Korea. Bacterial resistance to the nine commonly used antibiotics was evaluated by a standard disk diffusion technique based on the guidelines of the Clinical and Laboratory Standards Institute. The results demonstrated that most S. pseudintermedius isolates were resistant to penicillin (95.9%) or tetracycline (91.9%), but highly susceptible to amoxicillin/clavulanic acid (90.5%). Among the 74 isolates, 13 mecA-positive and methicillin-resistant S. pseudintermedius (MRSP) strains were identified, displaying a high level of resistance (84.6- 100%) to each of the individual antibiotics evaluated, with the exception of amoxicillin/clavulanic acid (46.2% resistance). Notably, all of the MRSP isolates exhibited simultaneous resistance to four or more different antibiotics, indicating that they are multiple drug resistant (MDR) strains. Taken together, these results imply that more careful selection or prescription of antibiotics for canine pyoderma and otitis externa should be required for reducing the emergence and/or spread of MDR strains, especially MDR-MRSP isolates, in veterinary pet clinics in Korea.

Combination of cyclosporin A and prednisolone for juvenile cellulitis concurrent with hindlimb paresis in 3 English cocker spaniel puppies.

Three 7-week-old, English cocker spaniel littermates were diagnosed as having juvenile cellulitis with concurrent neurologic signs based on history, histopathology, and therapeutic response. The puppies were treated with cyclosporin A and prednisolone. Skin lesions and hindlimb paresis improved following treatment.

Cyclosporine treatment of perianal gland adenoma concurrent with benign prostatic hyperplasia in a dog.

A 13-year-old, intact male, mixed-breed dog was evaluated for multiple intradermal nodules around the anus. The nodules were diagnosed as perianal gland adenoma based on histopathologic examination. After therapy with cyclosporin A for 5 wk, the perianal masses were moderately shrunken. The dog's condition has remained stable over 6 mo.

7.0-Tesla Tesla magnetic resonance imaging of granulomatous meningoencephalitis in a Maltese dog: a comparison with 0.2 and 1.5-Tesla.

A 6-year-old, intact female Maltese dog was presented with generalized seizures. Based on the neurological and physical examinations, intracranial lesion was suspected. Magnetic resonance imaging (MRI) of the brain was performed at three different magnetic field strengths (0.2, 1.5 and 7.0 T). Diffuse hypo- and hyperintense lesions involving the left caudate nucleus and internal capsule to the cranial diencephalon were identified on T2-weighted images. The detailed anatomical locations, the inflammatory and hemorrhagic changes of the lesions could be detected more apparently at 7.0 T. Histopathologically, granulomatous meningoencephalitis (GME) was diagnosed. This is the first case describing histopathologically confirmed GME lesions using 0.2, 1.5 and 7.0 T clinical MR scanner.

Magnetic resonance imaging of the canine brain at 7 T.

The purpose of this study was to describe relevant canine brain structures as seen on T2-weighted images following magnetic resonance (MR) imaging at 7 T and to compare the results with imaging at 1.5 T. Imaging was performed on five healthy laboratory beagle dogs using 1.5 and 7 T clinical scanners. At 1.5 T, spin echo images were acquired, while gradient echo images were acquired at 3 T. Image quality and conspicuity of anatomic structures were evaluated qualitatively by direct comparison of the images obtained from the two different magnetic fields. The signal-to-nose ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared between 1.5 and 7 T. The T2-weighted images at 7 T provided good spatial and contrast resolution for the identification of clinically relevant brain anatomy; these images provided better delineation and conspicuity of the brain stem and cerebellar structures, which were difficult to unequivocally identify at 1.5 T. However, frontal and parietal lobe and the trigeminal nerve were difficult to identify at 7 T due to susceptibility artifact. The SNR and CNR of the images at 7 T were significantly increased up to 318% and 715% compared with the 1.5 T images. If some disadvantages of 7 T imaging, such as susceptibility artifacts, technical difficulties, and high cost, can be improved, 7 T clinical MR imaging could provide a good experimental and diagnostic tool for the evaluation of canine brain disorders.

Syringomyelia in three small breed dogs secondary to Chiari-like malformation: clinical and diagnostic findings.

Three small breed dogs were referred for the evaluation of neurologic deficits. Upon physical and neurologic examination, all dogs displayed hyperesthesia, pain, and neck stiffness. Magnetic resonance imaging was performed on the brain and spinal cord, and all three dogs presented Chiari- like malformations and syringomyelia. These dogs were treated with prednisolone and furosemide, and showed rapid improvement of clinical signs. Chiari malformations and syringomyelia were not improved because of congenital disorders. This case report demonstrates the clinical and diagnostic features of Chiari-like malformations and syringomyelia in three small breed dogs.

18F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging findings of primary intracranial histiocytic sarcoma in a dog.

A 10-year-old, neutered male, Maltese dog presented with a three week history of intention tremor, right hind limb rigidity, poor coordination, and occasional circling to the left. On magnetic resonance imaging (MRI) of the brain, a mass was identified in the right occipital lobe and cerebellum. Three weeks after the initial MRI scan, we performed an (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) of the brain. The FDG-PET demonstrated areas of hypermetabolism in the right occipital lobe, cerebellum, pons, and medulla oblongata. When the standardized uptake value was calculated, the hypermetabolic lesion was higher than the gray matter values. The anatomical location of the hypermetabolic lesion was more precisely identified by the PET-MRI fusion images. The dog was definitively diagnosed as a primary histiocytic sarcoma of the brain. This is the first report of PET findings of an intracranial histiocytic sarcoma in a dog.

Effects of electroacupuncture on intraocular pressure and hemodynamic parameters in isoflurane anesthetized dogs.

The effects of electroacupuncture (EA) on intraocular pressure (IOP) and hemodynamic parameters were evaluated in isoflurane anesthetized 10 (5 males, 5 females) normal mongrel dogs (8.1-9.8 kg, 6-8 years old). After determination of baseline IOP and hemodynamic parameters (cardiac index, systolic arterial pressure, diastolic arterial pressure, heart rate and systemic vascular resistance index), EA was applied at 3 acupoints (LI-4, LIV-3 and GB-37) for 20 min. After the EA treatment, IOP was significantly decreased in the both eyes (p<0.05). However, there were not significant differences in hemodynamic parameters between those of before and after EA treatment. From these results, the EA treatment at LI-4, LIV-3 and GB-37 would be considered one of the valuable methods for the IOP treatment in dogs.

Therapeutic trial of granulocyte-colony stimulating factor for dilated cardiomyopathy in three dogs.

Three dogs were presented to us for evaluation of cardiac problems. Electrocardiographic recordings revealed severe tachyarrhythmia and atrial fibrillation with ventricular tachycardia in 2 of the 3 dogs. The echocardiographic findings of the 3 dogs revealed markedly decreased fractional shortening and a marked increase in E-point septal separation. Based on the results of electrocardiographic and echocardiographic evaluation, the 3 dogs were diagnosed as dilated cardiomyopathy (DCM). The dogs were treated with conventional cardiac medication, but cardiac function did not improve and the clinical signs remained. We subsequently attempted treatment with granulocyte-colony stimulating factor (G-CSF; 10 microg/kg, subcutaneously). The specific purpose of G-CSF therapy for DCM was to improve cardiac function and a significant improvement in cardiac function was confirmed. The three dogs had no treatment side effects. This case report suggests that G-CSF might have therapeutic effects for medically refractory DCM in dogs.

Determination of optimal dose of arginine vasopressin in hemorrhagic shock in dogs.

The hemodynamic effects of vasopressin of high/low doses on dogs were investigated using experimentally induced hemorrhagic shock model. Experimental groups were categorized according to administered doses of vasopressin (0.1, 0.4 and 1.6 IU/kg) and hemodynamic parameters were measured before and after the graded-dose administration of vasopressin. Administration of high- and middle-dose vasopressin (0.4 and 1.6 IU/kg) showed superior increase in blood pressure and systemic vascular resistance, compared with those of low-dose one (0.1 IU/kg). Results of systolic arterial pressure and mean arterial pressure in 1.6 IU/kg-administered group revealed lower efficacy than that in 0.4 IU/kg group in spite of administration of higher dose. This study demonstrates that 0.4 IU/kg of vasopressin can be used as the most effective dose for improving hemodynamic condition in the decompensatory phase of hemorrhagic shock in dogs.