Klebsiella pneumoniae infection secondary to bovine viral diarrhea in two prematurely born calves

Abstract: This paper describes the development of neurological signs of two prematurely born calves four days after birth. The pathological examination results indicated fibrinopurulent polyserositis, including meningoencephalitis with suppurative bronchopneumonia. Bovine viral diarrhea virus subtype 2a was detected in most of the internal organs, and the bacterial colonies cultured from the samples were identified as Klebsiella (K.) pneumoniae. Molecular analysis via multilocus sequence typing identified a different K.pneumoniae isolate in each calf-type 14 in calf A and type 65 in calf B. This is the first report identifying K.pneumoniae sequence types 14 and 65 in cattle.

Pathological, immunohistochemical, and bacteriological findings in dogs infected with Brucella canis

This study describes pathological, immunohistochemical, and bacteriological findings in adult dogs and fetuses naturally infected with Brucella (B) canis. A total of 42 dogs including 40 dogs and 2 aborted fetuses were examined. The most common gross lesions in infected dogs were swelling of lymph nodes and spleen. The testes showed marked swelling with multifocal to diffuse reddish discoloration. The most significant histopathological lesions were observed in the placenta. Placental trophoblasts were markedly hypertrophied due to the accumulation of intra-cellular gram-negative bacteria. Lymphocytic inflammation of varying severity was observed in the reproductive organs such as male testis, epididymis, and prostate gland and female uterus. Strong immunolabelling was observed in the cytoplasm of most trophoblasts in the placental tissues using immunohistochemistry. However, immunohistochemical staining did not demonstrate any organisms in other organs of dogs and fetuses. B. canis isolates were most frequently obtained from the whole blood (82.5%) and superficial inguinal lymph node (77.5%) in both sexes. In addition, the isolation rate was higher in male genital organs than in those of females. Hence, management of male dogs is most important because infected dogs can play a role as carriers.

A rare case of bovine tuberculosis caused by Mycobacterium bovis in a domestic rabbit

A 12-month-old domestic rabbit died suddenly without specific clinical signs. Gross examination revealed irregular yellowish hepatic nodules with pus in the submandibular muscles, lungs, uterus, and small intestines. Histopathological examination of the liver showed granulomatous inflammation with acid-fast-positive bacteria. Mycobacterium bovis SB1040 was identified by polymerase chain reaction and spoligotyping, and Pasteurella multocida was isolated from the multiple lesions. This report demonstrates the pathological features of rare bovine tuberculosis (bTB) in a domestic rabbit, the first case in the Republic of Korea. To ensure public safety, we recommend routine monitoring of rabbits to control the incidence of bTB.

Molecular subtyping and antimicrobial susceptibility of Streptococcus dysgalactiae subspecies equisimilis isolates from clinically diseased pigs

Background@#Streptococcus dysgalactiae subspecies equisimilis (SDSE) acts as an etiological agent for lameness, neurological signs, and high mortality in pigs. Despite its importance in pig industries and zoonotic potential, little is known about the effects of this pathogen. @*Objectives@#This study aimed to determine the molecular characteristics and antimicrobial resistance of SDSE strains isolated from diseased pigs. @*Methods@#A total 11 SDSE isolates were obtained from diseased pigs. Bacterial identification, PCR for virulence genes, emm typing, and antimicrobial resistance genes, multilocus sequence typing, and antimicrobial susceptibility test were performed. @*Results@#Nine isolates were from piglets, and 8 showed lameness, sudden death, or neurological signs. The isolates were PCR-positive for sla (100%), sagA (100%), and scpA (45.5%), and only 1 isolate amplified the emm gene (stL2764). Eight different sequence types were detected, categorized into 2 clonal complexes and 4 singletons. All the isolates in this study were included in a small cluster, which also contained other strains derived from humans and horses. The minimum inhibitory concentrations for the tested beta-lactams were low, while those for macrolides, tetracyclines, and fluoroquinolones were relatively high. PCR analysis of the macrolide and tetracycline resistance genes demonstrated that the isolates carried erm(B) (18.2%, n = 2), mef(A/E) (9.1%, n = 1), tet(M) (18.2%, n = 2), and tet(O) (90.2%, n = 10). Two isolates presented a mutation in parC, which is associated with fluoroquinolone resistance. @*Conclusion@#This study provided insight into swine-derived SDSE, as it is related to veterinary medicine, and elucidated its zoonotic potential, in the context of molecular epidemiology and antimicrobial resistance in public health.

Co-infection of Dirofilaria immitis and Japanese encephalitis virus in a spotted seal (Phoca largha) in the Republic of Korea

A 10-year-old male spotted seal presented with loss of appetite and decreased activity. Grossly, the internal organs revealed several filarial nematodes in the right ventricle of the heart and the pulmonary vessels. Histopathological examination of the brain revealed moderate nonsuppurative meningoencephalitis with glial nodules and neuronophagia. Japanese encephalitis virus (JEV) of genotype I was isolated from the brain. All nematodes were identified as Dirofilaria immitis. This is the first clinical case of co-infection with D. immitis and JEV in a seal, suggesting that the seal, may be a dead-end host, like the human and horse, for JEV.

Necrotizing Enteritis Caused by Pharyngostomum cordatum Infection in a Stray Cat

A stray female cat of unknown age, presenting bright red watery diarrhea, was submitted to the Animal and Plant Quarantine Agency for diagnosis. In the small intestines extracted from the necropsied cat, numerous white oval-shaped organisms were firmly embedded in the mucosa and there was thickening of intestinal wall. Histopathological analysis revealed severe necrotizing enteritis, together with atrophied intestinal villi, exfoliated enterocytes, and parasitic worms. Recovered worms were identified as Pharyngostomum cordatum by morphological observation and genetic analysis. Although P. cordatum is known to occur widely in Korea, this is the first clinical description of an infection by P. cordatum causing severe feline enteritis.

Pathologic and molecular characterization of Streptococcus dysgalactiae subsp. equisimilis infection in neonatal piglets

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging pathogen in animals and humans. Herein, we describe two clinical swine cases of SDSE infection presenting with lameness, neurological signs, or sudden death. Pathological examination indicated suppurative arthritis, encephalitis, and multifocal abscesses in kidney and heart. The β-hemolytic colonies obtained from joint samples of each case were identified as SDSE. The two isolates had low minimum inhibitory concentrations for β-lactams, and they presented the same virulence gene profile (slo⁻/sagA⁺/pSTKP8⁺). Molecular analysis by multilocus sequence typing identified the SDSE isolates from cases 1 and 2 as sequence types 315 and 252, respectively.

Prevalence state of canine brucellosis in South Korea during 2015 and 2016 / 대한수의학회지

We investigated the prevalence of canine brucellosis in companion and stray dogs between March 2015 and December 2016 and determined the disease characteristics based on the geographic distribution, sex and age of the dogs in South Korea. We conducted a large-scale survey using serological and bacteriological tests. Samples were collected from 2,394 dogs (1,825 companions and 569 strays). Thirty (1.3%) samples were positive for Brucella canis antibodies including 16 (0.9%) from companion dogs and 14 (2.5%) from stray dogs. Two (1.0%) of the 196 samples cultured from the stray dogs were positive. When compared with male dogs, the female companion and stray dogs had a significantly higher prevalence of brucellosis. Moreover, the prevalence of canine brucellosis was significantly higher in stray dogs older than 6 years and the prevalence of the disease in companion dogs was highest in Incheon (2.1%) and Jeolla (2.1%) provinces. Stray dogs from the Daejeon metropolitan area had the highest prevalence of brucellosis (7.9%). National control measures for canine brucellosis have not previously been implemented. Our findings suggest that appropriate screening tests and control measures are necessary to improve the health of dogs and to protect public health in Korea, particularly with the rapid growth of the companion animal industry.

Sudden death caused by trichlorfon poisoning in Korean native cattle / 대한수의학회지

Two 12-month-old cattle with anthelmintics containing trichlorfon the day before death presented to the Animal and Plant Quarantine Agency for diagnosis. In necropsy, they revealed enlargement of the spleens, redness of mucosa and serosa in stomachs and intestines, and friable kidneys. Histopathologically, hemorrhages in the spleens, omasums, abomasums, and intestines as well as renal tubular necrosis were observed. Trichlorfon was detected at above the lethal dose in the ruminal contents. Based on these findings, we diagnosed this case as death caused by trichlorfon poisoning.

Ectopic migration of Dirofilaria immitis in a Eurasian otter (Lutra lutra) in Korea / 대한수의학회지

An 8-year-old female Eurasian otter (Lutra lutra) reared in a wetland center, died 2 h after sudden onset of astasia and dyspnea despite medical treatment. Gross examination of internal organs revealed 10 adult filarioid nematodes in the right ventricle of the heart and three between the left and right cerebral hemispheres. All nematodes were identified as Dirofilaria immitis by direct microscopy and polymerase chain reaction assay. Histopathological observation revealed multifocal hemorrhage in the cerebral subarachnoid space and focal necrosis with hemorrhagein the cerebellar parenchyma. Although rare, veterinarians should consider cerebral dirofilariasis as a differential diagnosis in unexplained neurological cases.

Meningoencephalitis and pneumonia caused by Pasteurella multocida in rabbits / 대한수의학회지

Eight rabbits exhibited head tilt and subsequently died. At necropsy, three rabbits had crusty deposits in ears and four had reddish lungs. The main histopathological features were severe diffuse suppurative meningoencephalitis (75.0% of rabbits), fibrinopurulent pneumonia (37.5%), and otitis externa (37.5%). Pasteurella multocida (P. multocida) was isolated from brains, ears, and lungs. The capsular serogroups of the isolates were untypable. Based on histopathological features and bacterial analysis results, the rabbits were diagnosed as P. multocida infection. P. multocida infections might result in considerable economic loss in commercial rabbit production facilities in Korea.

Prevalence state of canine brucellosis in South Korea during 2015 and 2016

We investigated the prevalence of canine brucellosis in companion and stray dogs between March 2015 and December 2016 and determined the disease characteristics based on the geographic distribution, sex and age of the dogs in South Korea. We conducted a large-scale survey using serological and bacteriological tests. Samples were collected from 2,394 dogs (1,825 companions and 569 strays). Thirty (1.3%) samples were positive for Brucella canis antibodies including 16 (0.9%) from companion dogs and 14 (2.5%) from stray dogs. Two (1.0%) of the 196 samples cultured from the stray dogs were positive. When compared with male dogs, the female companion and stray dogs had a significantly higher prevalence of brucellosis. Moreover, the prevalence of canine brucellosis was significantly higher in stray dogs older than 6 years and the prevalence of the disease in companion dogs was highest in Incheon (2.1%) and Jeolla (2.1%) provinces. Stray dogs from the Daejeon metropolitan area had the highest prevalence of brucellosis (7.9%). National control measures for canine brucellosis have not previously been implemented. Our findings suggest that appropriate screening tests and control measures are necessary to improve the health of dogs and to protect public health in Korea, particularly with the rapid growth of the companion animal industry.

Sudden death caused by trichlorfon poisoning in Korean native cattle

Two 12-month-old cattle with anthelmintics containing trichlorfon the day before death presented to the Animal and Plant Quarantine Agency for diagnosis. In necropsy, they revealed enlargement of the spleens, redness of mucosa and serosa in stomachs and intestines, and friable kidneys. Histopathologically, hemorrhages in the spleens, omasums, abomasums, and intestines as well as renal tubular necrosis were observed. Trichlorfon was detected at above the lethal dose in the ruminal contents. Based on these findings, we diagnosed this case as death caused by trichlorfon poisoning.

Meningoencephalitis and pneumonia caused by Pasteurella multocida in rabbits

Eight rabbits exhibited head tilt and subsequently died. At necropsy, three rabbits had crusty deposits in ears and four had reddish lungs. The main histopathological features were severe diffuse suppurative meningoencephalitis (75.0% of rabbits), fibrinopurulent pneumonia (37.5%), and otitis externa (37.5%). Pasteurella multocida (P. multocida) was isolated from brains, ears, and lungs. The capsular serogroups of the isolates were untypable. Based on histopathological features and bacterial analysis results, the rabbits were diagnosed as P. multocida infection. P. multocida infections might result in considerable economic loss in commercial rabbit production facilities in Korea.

Ectopic migration of Dirofilaria immitis in a Eurasian otter (Lutra lutra) in Korea

An 8-year-old female Eurasian otter (Lutra lutra) reared in a wetland center, died 2 h after sudden onset of astasia and dyspnea despite medical treatment. Gross examination of internal organs revealed 10 adult filarioid nematodes in the right ventricle of the heart and three between the left and right cerebral hemispheres. All nematodes were identified as Dirofilaria immitis by direct microscopy and polymerase chain reaction assay. Histopathological observation revealed multifocal hemorrhage in the cerebral subarachnoid space and focal necrosis with hemorrhagein the cerebellar parenchyma. Although rare, veterinarians should consider cerebral dirofilariasis as a differential diagnosis in unexplained neurological cases.

Magnetic nanoparticle based purification and enzyme-linked immunosorbent assay using monoclonal antibody against enrofloxacin

Monoclonal anti-enrofloxacin antibody was prepared for a direct competitive enzyme-linked immunosorbent assay (ELISA) and purification system using monoclonal antibody (mAb) coupled magnetic nanoparticles (MNPs). The IC50 values of the developed mAb for enrofloxacin (ENR), ciprofloxacin, difloxacin, sarafloxacin, pefloxacin, and norfloxacin were 5.0, 8.3, 9.7, 21.7, 36.0, and 63.7 ng/mL, respectively. The lowest detectable level of ENR was 0.7 ng/mL in the prepared ELISA system. To validate the developed ELISA in the food matrix, known amounts of ENR were spiked in meat and egg samples at 10, 20 and 30 ng/mL. Recoveries for ENR ranged from 72.9 to 113.16% with a coefficient of variation (CV) of 2.42 to 10.11%. The applicability of the mAb-MNP system was verified by testing the recoveries for ENR residue in three different matrices. Recoveries for ENR ranged from 75.16 to 86.36%, while the CV ranged from 5.08 to 11.53%. Overall, ENR-specific monoclonal antibody was prepared and developed for use in competitive to ELISAs for the detection of ENR in animal meat samples. Furthermore, we suggest that a purification system for ENR using mAb-coupled MNPs could be useful for determination of ENR residue in food.

Characterization of multipotent mesenchymal stem cells isolated from adipose tissue and bone marrow in pigs / 대한수의학회지

Mesenchymal stem cells (MSCs) have ability to differentiate into multi-lineage cells, which confer a great promise for regenerative medicine to the cells. The aim of this study was to establish a method for isolation and characterization of adipose tissue-derived MSC (pAD-MSC) and bone marrow-derived MSC (pBM-MSC) in pigs. Isolated cells from all tissues were positive for CD29, CD44, CD90 and CD105, but negative for hematopoietic stem cell associated markers, CD45. In addition, the cells expressed the transcription factors, such as Oct4, Sox2, and Nanog by RT-PCR. pAD-MSC and pBM-MSC at early passage successfully differentiated into chondrocytes, osteocytes and adipocytes. Collectively, pig AD-MSC and BM-MSC with multipotency were optimized in our study.