Early detection of septic arthritis caused by Streptococcus dysgalactiae subspecies equisimilis in a dog – a case report

In this report, a seven-year-old English Pointer male with Streptococcus dysgalactiae subsp. equisimilis arthritis joint infection is presented. The dog was referred to the Internal Medicine Department Policlinics with the symptoms of anorexia, weakness, swollen joints and ulcerative wounds on testes. On physical examination, the dog was depressed and manifesting discomfort during manipulation of the fore and hind legs’ joints. There were palpable effusions of the right carpal, elbow, and tibiotarsal joints. Haematological and serum biochemical analyses showed mild anaemia, moderate thrombocytopaenia, and elevated alanine aminotransferase. As soon as the synovial fluid aspirates were obtained aseptically from the right elbow, radiocarpal, and tibiotarsal joints, they were sent to bacteriological examination. Symptomatic and supportive treatment was initiated immediately. Empirical enrofloxacin therapy was initially started. Bacteria which were cultivated from the synovial fluid aspirates specimen were identified as S. equisimilis. The isolate was found to be resistant to enrofloxacin and susceptible to amoxycillin/ clavulanic acid. According to the results of the antimicrobial susceptibility tests, enrofloxacin therapy was terminated and amoxycillin/clavulanic acid therapy was immediately started lasting for four weeks. The dog was treated successfully. To our knowledge, Streptococcus dysgalactiae subsp. equisimilis was isolated from the synovial fluid from a dog for the first time in Turkey, as it is rarely seen in dogs. Streptococcus spp., arthritis, swollen joint, antimicrobial susceptibility Infectious arthritis is a common problem usually caused by bacterial agents that affect various species including humans, horses, and dogs. Septic arthritis which may cause pain, swelling, and lameness, is usually a monoarthropathy in dogs. Several different bacteria species, especially Staphylococcus intermedius, S. aureus and β-haemolytic streptococci have been isolated from septic arthritis in dogs (Bennett and Taylor 1988; Clements et al. 2005). Lancefield group-C streptococci are a common cause of infection in animals but rarely detected in humans (Bradley et al. 1991). Streptococcus dysgalactiae subsp. equisimilis (S. equisimilis) is a large-colony type (> 0.5 mm) Lancefield group C-haemolytic streptococcus that can rarely cause septic arthritis (Ike 1990). Septic arthritis may be suspected on the basis of clinical presentation: typically severe lameness and thickened painful joint(s) with or without concurrent systemic signs such as pyrexia, anorexia, and depression (Fearnside and Preston 2002). Clinical findings and medical treatment A seven-year-old English Pointer male, weighing 15 kg, was referred to the Internal Medicine Department Clinics with anorexia, weakness, swollen joints (Plate VIII, Fig. 1) and ulcerative wounds on testes. The anamnesis included that the patient’s owner had left the dog with his friend for 15 days. The dog’s symptoms started to appear after that time and the dog’s food intake started to decrease day by day. ACTA VET. BRNO 2014, 83: 261–264; doi:10.2754/avb201483030261 Address for correspondence: Banu Dokuzeylül, DVM, PhD Istanbul University, Faculty of Veterinary Medicine Department of Internal Medicine Avcılar Campus, 34320, Avcılar, Istanbul, Turkey Phone: +90 212 4737070 (17131) E-mail: [email protected], [email protected] http://actavet.vfu.cz/ On physical examination, the dog was depressed and exhibiting discomfort during manipulation of the fore and hind leg joints. The dog’s rectal temperature was 39.6 °C and the respiration rate was 23/min. By palpation there were effusions of the right carpal, elbow, and tibiotarsal joints. No abnormality was detected on orthopaedic examination. It was checked with radiography and hand examination. The dog showed no abnormality during walking. Haematological and serum biochemical analyses revealed mild anaemia (Haematocrit (HCT): 29 %), moderate thrombocytopaenia (Platelets (PLT): 150 × 103 μl) and elevated alanine aminotransferase (ALT): 275 IU/l. Because it was a hunting dog, rapid tests for ehrlichiosis, anaplasmosis, dirofilariasis, Lyme disease (Snap®, 4Dx®, Idexx Laboratories, USA), and leishmaniasis (Snap® Leishmania, Idexx Laboratories, USA) were performed with a negative result. Synovial fluid aspirates were obtained aseptically from the right elbow, radiocarpal, and tibiotarsal joints. The samples were sent to the Department of Microbiology laboratory for bacteriological examination, and inoculated onto Nutrient agar supplemented with 7% sheep blood, MacConkey agar plates and into Nutrient broths. While MacConkey agar plates were incubated only aerobically, other plates were incubated aerobically, anaerobically, and microaerobically at 37 °C for 24 to 48 h. The colonies were observed macroscopically, and then microscopic observation of a gram stain was done. Further identification was performed by conventional biochemical activity tests and Lancefield serogrouping (Quinn et al. 1999). The antibiotic susceptibility test according to Kirby-Bauer method recommended by the CLSI was performed to select the convenient antimicrobial agent for treatment (CLSI document M100-S18 2008). As soon as the samples for bacteriological examination were taken, symptomatic and supportive therapy was immediately started. The dog was an ambulatory patient. Serum transfusion therapy (5% dextrose solution, 400 ml, IV), phenoxy methyl propionic acid (Hepagen, Vetaş, Turkey) at the dose of 1.5 ml/dog/day i.m., enrofloxacin (Baytril, Bayer, Turkey) at the dose of l.5 ml/dog/day i.m., B complex vitamins (Berovit, Ceva, Turkey) 2 ml/dog/day i.m., ranitidine (Ulcuran, Abfar, Turkey) at the dose of 1.2 ml/dog, i.m. BID, vitamin E (Evicap, Koçak Farma, Turkey) at the dose of 200 IU/dog/day p.o., were applied for a week. Topical iodine therapy was applied to ulcerative wounds. Low protein diet was also advised to the dog’s owner. After one week from this therapy, haematological and serum biochemical analyses were made again at the Faculty’s laboratory. Complete blood count indicators, HCT and PLT, were determined as 38% and 300 × 103 μl, respectively. Elevated ALT (275 IU/l) was decreased to 175 IU/l. Fore and hind leg joints were again checked with radiography. No abnormalities were detected at the area of joints (Plate IX, Fig. 2). Beta-haemolytic, 1–2 mm diameter, translucent colonies were observed as pure cultures on the blood agar plates. Characteristic Gram positive cocci in the chain formation were observed after Gram staining from broth culture. Streptococcus equisimilis was identified on the basis of bacteriological examination. The results of antimicrobial susceptibility testing indicated that the isolate was resistant to cloxacillin (6 μg/ml), enrofloxacin (5 μg/ml), erythromycin (5 μg/ml), gentamycin (10 μg/ml), lincomycin (25 μg/ml), rifampin (25 μg/ml), sulphamethoxazole/trimethoprim (23.75/1.25 μg), and susceptible to ampicillin (10 μg), amoxycillin/clavulanic acid (20/10 μg), amoxycillin (25 mg/ml), ampicillin-sulbactam (10/10 μg), ceftriaxone (30 μg), cefoperazone (75 μg), oxytetracycline (30 μg/ml), penicillin G (10 units), tetracycline (20 μg/ml), cephazolin (30 μg/ml), vancomycine (30 μg/ml), cephalothin (30 mg), cephoxitin (30 μg/ml). According to the results of the antimicrobial susceptibility tests, enrofloxacin therapy (Baytril®, l.5 ml, i.m., SID) was terminated and amoxycillin/clavulanic acid (Synulox, Pfizer, Turkey) at the dose of 12.5 mg/kg p.o. BID treatment was immediately started. The 262