Vol.45 No.3, September 30, 2022
Abstract : Pathogens such as feline herpesvirus, feline calicivirus, Bordetella bronchiseptica, Chlamydia felis, Mycoplasma felis and Pasteurella multocida usually cause feline upper respiratory tract disease (URTD). Real-time PCR was used to analyze the detection and prevalence of the most common respiratory pathogens in cats with (n=69) and without respiratory signs (n=31). Pathogens were detected in 53 cats, divided into 37 (69.8%) with a single pathogen, 15 (28.3%) with two pathogens, and 1 (1.9%) with three pathogens. M. felis had the highest detection rate in 29 (42.0%) cats, P. multocida was detected in 18 (26.1%), FHV in 10 (14.5%), FCV in 7 (10.1%), B. bronchiseptica in 3 (4.3%), and C. felis in 2 (2.9%). M. felis was the most frequently detected pathogen in cats living outdoors without vaccination. Of the 37 cats infected with single pathogen, nasal discharge was observed in 13 (35.1%), ocular signs in 6 (16.2%), drooling in 5 (13.5%), dyspnea in 3 (8.1%), and asymptomatic in 10 (27.0%). In 51 outdoor and 49 indoor cats, pathogens were detected in 35 (68.6%) and 18 (36.7%) cats, respectively. Of the 29 cats infected with M. felis, 22 (75.9%) showed respiratory signs, and 7 (24.1%) were healthy. In the age of the 53 positive cats, 10 (18.9%) were under the age of 1 year, 26 (49.1%) were aged 1∼3 years, and 17 (32.1%) were aged 3 years or older. Although the number of cats in the study was small, the results can provide valuable data on the prevalence of URTD in Korean cats.
Abstract : This study was conducted for safety evaluation on 130 pet food products, which are distributed in Gwangju, South Korea. The microbial contamination part and the usage of food additives part were mainly investigated. The five microorganisms that we tested were total viable cell counts (TVC), Coliforms, Salmonella spp., Campylobacter spp., pathogenic Escherichia coli and there were 15 products that exceed the microbial criteria or detected food poisoning bacteria. Specifically, Coliforms (13 products, 10%), TVC (9 products, 6.9%), Salmonella spp. (2 products, 1.5%), and E. coli (2 products, 1.5%) were followed. On the other hand, food additives such as preservatives, antioxidants and sodium nitrite were detected in 61 products. Among the preservatives, sorbic acid and benzoic acid were detected in 58 (44.6%) products. In antioxidants, Butylated hydroxytoluene (BHT) was detected in 3 (2.3%) products. In addition, preservatives and antioxidants were detected in 8 of 20 products labeled as ‘additive-free’. Microbial contamination tended to occur mainly in small-scale individual homemade feed stores, while food additives were all detected in pet shops and supermarkets. Currently, the criteria for microorganisms and food additives for pet foods are insufficient in Korea. So, it is necessary to establish detailed feed standards and specifications for companion animals.
Abstract : Immune-mediated hemolytic anemia (IMHA) is autoimmune disease which is anemia caused by own immune system destroying the red blood cells (RBC). It can be diagnosed with spherocytosis, positive auto-agglutination of RBCs and direct antiglobulin test (DAT, Coomb’s test). The treatment for IMHA are blood transfusion, immunosuppressive agents including glucocorticoids and other supportive therapies. Danazol is synthetic androgen that has effect of interfering the autoimmune reaction to RBCs. It can be used as an adjunctive agent in addition to glucocorticoids. To investigate its effectiveness, the medical records of 10 IMHA-diagnosed dogs were evaluated. All subjects were treated with blood transfusion, prednisolone, mycophenolate mofetil, and intravenous human immunoglobulin G. Additionally, 6 subjects were administered with danazol and 4 subjects were not. The results of initial blood examination and responses to the treatment for IMHA were compared between the groups. There were significant differences in the number of blood transfusions; once in group with danazol, twice in group without danazol, duration of recovery to normal hematocrit; 7.67±3.08 days in group with danazol, 22.00±5.66 days in group without danazol, and hospitalization; 5.17±0.75 days in group with danazol, 12.75±2.22 days in group without danazol. Therefore, danazol has potential effective on treating IMHA for rapid improvement.
Abstract : The aim of this study was to investigate the prevalence of antimicrobial resistance and virulence factors in staphylococci isolated from canine otitis externa. A total 295 causative microorganisms were isolated. The most common isolated species were Staphylococcus (S) pseudintermedius (94 isolates) followed by Pseudomonas aeruginosa (60 isolates), S. schleiferi (25 isolates), Escherichia coli (23 isolates) and Proteus mirabilis (20 isolates). Staphylococci isolates were showed high resistance to penicillin (78.6%), erythromycin (55.9%), tetracycline (52.4%), clindamycin (51.7%) and ciprofloxacin (42.8%). Of the 145 staphylococci isolates, 49 (33.8%) methicillin—resistant staphylococci (MRS) were observed, distributed among S. pseudintermedius (n=34), S. schleiferi (n=6), S. epidermis (n=4), S. hominis (n=2), S. aureus, S. caprae and S. saprophyticus (n=1, respectively). Forty-three (87.8%) of 49 MRS and 10 (10.4%) of 96 methicillin—susceptibility staphylococci harbored mecA gene. About 80% of MRS were multidrug-resistant with resistance to at least one antibiotic in three or more antibiotic classes. Resistance genes blaZ (93/114, 81.5%), ermB (35/81, 43.2%), ermC (3/81, 3.7%), aacA-aphD (50/54, 92.5%), tetM (69/76, 90.7%) and tetK (6/76, 7.8%) were detected among resistant isolates. Virulence factors genes lukF and lukS were found in 100%(145/145) and 43.4%(63/145), respectively. Genes encoding ermA, eta , etb and tsst were not detected. To the best of our knowledge, this is the first study which investigated for the presence of genes encoding antimicrobial resistance and staphylococcal toxins in staphylococci isolated from canine otitis externa. A continuous monitoring and surveillance program to prevent antimicrobial resistance in companion animals is demanded.
Abstract : Streptococcus is one of the major pathogen groups inducing bovine mastitis. The aim of this study was to investigate the antimicrobial resistance patterns of Streptococcus species isolated from bovine mastitis milk samples in Korea from 2016 to 2021. In total, 181 (10.3%) Streptococcal isolates were collected from 1,761 quarter milk samples at 122 farms; S. uberis 39.2% (n=71), S. dysgalactiae 29.3% (n=53), S. equinus 9.9% (n=18), S. suis 6.1% (n=11), S. parauberis 4.4% (n=8), S. lutetiensis 3.9% (n=7), others 7.2% (n=13). However, S. agalactiae was not isolated. The isolates showed the highest resistance rate to tetracycline (55.2%) followed by erythromycin (45.3%) and pirlimycin (36.5%). In contrast, all isolates were susceptible to ceftiofur, cephalothin, penicillin/novobiocin, and only single S. equinus isolate was resistant to both ampicillin and penicillin. Of 181 isolates, 64 (35.4%) were multidrug resistance (MDR). The resistance to pirlimycin of S. uberis (73.2%) was much higher than that of other species (0∼36.4%). All S. suis isolates were resistance to tetracycline. S. dysgalactiae showed lower resistance to erythromycin, pirlimycin and tetracycline than S. uberis and S. suis . The rate of MDR was relatively higher among S. uberis (73.2%) than among S. suis (36.4%), S. dysgalactiae (15.1%), others (0%). In conclusion, antimicrobial resistance in Streptococcus spp. should be regularly examined for appropriate therapies because the resistance patterns were various among the individual species.
Abstract : We investigated the virulence genes, O-serotypes, antimicrobial resistance of pathogenic E. coli isolated from carcasses (n=455) and environmental (n=372) samples of 11 cattle and 12 pig slaughterhouses from December 2020 to December 2021. E. coli were isolated from nine carcasses (2.0%), three slaughter facilities (1.4%), two utensils (2.7%) and three abattoir workers (3.5%) from four cattle and four pig slaughterhouses. Among all isolates, 13 STEC (76.5%) were identified, followed by four EPEC (23.5%). As a result of the antibiotic susceptibility test, all isolates were resistant to at least one antimicrobial, of which 70.6% isolates showed multidrug resistance patterns. The serotypes were diverse in pigs compared to cattle, with serotypes O18, O66, O109 in cattle and O9, O76, O85, O100, O153, and O159 in pigs. In a single cattle slaughterhouse, eight STEC O66 were isolated from various types of sample (4 slaughter animal surfaces, 3 gloves, and 1 knife) with two antimicrobial resistance patterns (CHL-FIS-STR and CHL-FIS). Those two types of strain were suspected crosscontamination from utensils to slaughter animal surfaces. These results showed that pathogenic E. coli were detected in carcasses and various environmental samples in cattle and pig slaughterhouses. Nationwide monitoring and hygiene management are required to prevent cross-contamination of STEC isolate slaughterhouses.
Abstract : An epidemiological study was conducted to investigate five diarrhea-causing pathogens (coronavirus, rotavirus, E. coli, Cryptosporidium, Giardia) using a rapid diagnostic kit in Hanwoo calves with diarrhea in Chungcheongbuk-do, Korea, from 2018 to 2021. A total of 22,417 fecal samples were collected from calves under 1 year of age; of those, 13,518 (60.3%) were positive for five bovine diarrhea antigens. The antigen positivity rates for rotavirus, coronavirus, E. coli, Giardia, and Cryptosporidium were 34.5%, 11.0%, 8.2%, 4.7%, and 2.0%, respectively. The prevalence of the five pathogens in calves was statistically higher in autumn and winter. The highest prevalence of the pathogens was observed in the under 1 month age group, and the incidence of diarrhea decreased with age. Rotavirus was a major pathogen in calves under 1 month of age, whereas the prevalence of E. coli increased with age. This study provides epidemiological evidence of the prevalence of calf diarrheal pathogens in Chungcheongbuk-do, Korea, which will facilitate early diagnosis and development of measures against calf diarrhea.
Abstract : Bovine viral diarrhea (BVD) is one of the problematic wasting diseases in cattle leading to huge economic losses. This study was conducted to investigate the prevalence of BVD including transient and persistent infection from cattle farms in Gyeongsangnam-do. A total of 2,667 blood samples from 24 farms were collected and the sera were subjected to ELISA to detect BVD virus (BVDV) antigen, Erns. 5’ untranslated region (5’-UTR) of BVDV-positive samples was sequenced to identify the genotype, and compared with isolates previously reported elsewhere. There were fourteen BVDV-positive calves from 2,667 samples (positive rate: 0.52%) from first ELISA testing followed by eight persistently infected out of eleven BVDV-positive samples (72.73%) in secondary ELISA that was conducted in at least four weeks suggesting the circulation of BVDV in the area. Sequencing analysis exhibited that thirteen BVDV-positive samples were identified as BVDV-1b and one sample was BVDV-2a. Phylogenetic analysis revealed that the BVDV-1b-positive samples showed the highest homology in nucleotide sequence to Korean isolates collected from Sancheong, Gyeongsangnam-do, while the BVDV-2a-positive sample (21GN7) was more similar to reference strains collected outside South Korea. This study will provide the recent fundamental data on BVD prevalence in Gyeongsangnam-do to be referred in developing strategies to prevent BVDV in South Korea.
Abstract : Cataracts occur commonly in older dogs, which can lead to partial or complete vision loss. In the present study, a 12-year-old male poodle presented for evaluation of ocular sinister (OS) cataract. This study was a clinical case report on the process of performing surgery using phacoemulsification (PHACO) and the problems that arise in patient diagnosed with OS cataract. In the oculus dexter (OD), the artificial eye was inserted because there was no electroretinography (ERG) response. In the OS, the ERG was 51.6 μV, so operation was performed because the visual pathway function remained. Slit-lamp biomicroscopy of the OS showed complete loss of vision as a hypermature cataract and that the lens was hardened. During the cataract surgery using PHACO, visco-elastic agents were used to maintain the shape of the eyeball, and the PHACO procedure took 3.13 minutes. The hardened lens and visco-elastic agents were removed from the eye through PHACO surgery, and the operation was completed by inserting an intraocular lens (IOL). As a result of managing IOP for 2 months after surgery, it remained stable at a maximum of 19 mmHg, and no postoperative ocular hypertension (POH) occurred. Currently, one year has passed since the operation, and the dog maintains its daily life with its left eye without any problems.
Abstract : This study describes an analytical method based on LC-MS/MS for the quantitation of 5 fluoroquinolones (Enrofloxacin, Ciprofloxacin, Marbofloxacin, Norfloxacin and Danofloxacin) in meat, and was applied to 230 meat samples for validation. Quantitation was performed based on a matrix-matched calibration to compensate for the matrix effect on the electrospray ionization. Good linear calibrations (R2≥0.998) were obtained for all fluoroquinolones at 6 concentrations of 1∼50 μg/kg. Satisfied recoveries of all fluoroquinolones were demonstrated in spiked meat at three levels from 10 to 50 μg/kg. The recoveries ranged between 75.8∼99.2% in beef, 80.1∼99.6% in pork and 72.2∼99.8% in chicken, respectively. The limits of quantitation (LOQs) for fluoroquinolones ranged from 0.7 to 3.2 μg/kg. We also monitored fluoroquinolones residue in the sample (beef 107, pork 71, chicken 52) using LC-MS/MS. Residues of fluoroquinolones which exceeded maximum residue limits (MRL) were not exceed in any of the 230 samples.
Abstract : The simultaneous analysis of mycotoxins using LC-MS/MS, a food official analysis method, was applied with compound feed for pets with high consumer preferences. In this study, the linearity of all calibration curves showed good linearity of 0.99 or more. and both the accuracy (recovery rate) and precision (repeatability) criteria of the concentration range for each mycotoxin in the National Agricultural Products Quality Management Service’s Validation and Verification Guidelines were met. And as a result of analyzing FAPAS QCM in the same way, it was assesed that the z-scores of Aflatoxin B1, Ochratoxin A, Zearalenone, and Fumonisin B1, were within ±2 range. This study showed that the application of the food official analysis method to compound feed for pets is suitable.
Abstract : The HPLC conditions for analysis of ivermectin in solutions dosage forms of commercial anthelmintics are different for each product. The purpose of this study was to establish a standardized chromatographic method for the quantification of ivermectin in solution. The separation was achieved on Waters Xbridge C18 column (4.6×150 nm, 5 μm) using different kinds of mobile phase composed of water/methanol/acetonitrile (15/34/51, v/v and 19.5/27.5/53, v/v), with UV detection at wavelengths 245 nm and 254 nm. A total of five commercial ivermectin in solution samples were analyzed. In this study, the optimal chromatographic conditions for analysis of ivermectin in solution were mobile phase of water/methanol/acetonitrile (15/34/51, v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 245 nm using a Waters Xbridge C18 column (4.6×250 nm, 5 μm) at a column temperature of 25℃. The linearity was observed in the concentration range of 50∼150 μg/mL, with a correlation coefficient, r2=0.99999. The limit of detection and the limit of quantification were 0.88 and 2.68 μg/mL, respectively. The accuracy (% recovery) was found to be 98.9 to 100.3%. Intraday and Intermediate precisions with relative standard deviations were less than 1.0%. The content of ivermectin for five market samples ranged 91.2∼102.7%. The proposed method was also found to be robust, therefore, the method can be used for the routine analysis of ivermectin in solutions dosage forms.
Yeonsu Oh, Suk Hoon Yoon, Dong-Seob Tark, Ho-Seong ChoKorean J. Vet. Serv. 2021;44: 283-290 https://doi.org/10.7853/kjvs.2021.44.4.283
Myoungoon Oh, Kyoung Bo Ko, Seong Cheol Cho, Jin-A Ko, YounChul RyuKorean J. Vet. Serv. 2021;44: 175-183 https://doi.org/10.7853/kjvs.2021.44.4.175