Molecular surveillance of zoonotic pathogens from wild rodents in the Republic of Korea.

BACKGROUND: Rodents are recognized as major reservoirs of numerous zoonotic pathogens and are involved in the transmission and maintenance of infectious diseases. Furthermore, despite their importance, diseases transmitted by rodents have been neglected. To date, there have been limited epidemiological studies on rodents, and information regarding their involvement in infectious diseases in the Republic of Korea (ROK) is still scarce. METHODOLOGY/PRINCIPAL FINDINGS: We investigated rodent-borne pathogens using nested PCR/RT-PCR from 156 rodents including 151 Apodemus agrarius and 5 Rattus norvegicus from 27 regions in eight provinces across the ROK between March 2019 and November 2020. Spleen, kidney, and blood samples were used to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato group, Coxiella burnetii, Leptospira interrogans, and severe fever with thrombocytopenia syndrome virus (SFTSV). Of the 156 rodents, 73 (46.8%) were infected with Bartonella spp., 25 (16.0%) with C. burnetii, 24 (15.4%) with L. interrogans, 21 (13.5%) with A. phagocytophilum, 9 (5.8%) with SFTSV, and 5 (3.2%) with Borrelia afzelii. Co-infections with two and three pathogens were detected in 33 (21.1%) and 11 rodents (7.1%), respectively. A. phagocytophilum was detected in all regions, showing a widespread occurrence in the ROK. The infection rates of Bartonella spp. were 83.3% for B. grahamii and 16.7% for B. taylorii. CONCLUSIONS/SIGNIFICANCE: To the best of our knowledge, this is the first report of C. burnetii and SFTSV infections in rodents in the ROK. This study also provides the first description of various rodent-borne pathogens through an extensive epidemiological survey in the ROK. These results suggest that rodents harbor various pathogens that pose a potential threat to public health in the ROK. Our findings provide useful information on the occurrence and distribution of zoonotic pathogens disseminated among rodents and emphasize the urgent need for rapid diagnosis, prevention, and control strategies for these zoonotic diseases.

Comparison of oxidative stress status in dogs undergoing laparoscopic and open ovariectomy.

The present study evaluated and compared the oxidative stress status of dogs undergoing laparoscopic or open ovariectomy. Twelve healthy female dogs were divided into two groups according to the type of the surgical procedure, laparoscopic or open ovariectomy. Plasma total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) levels for the evaluation of oxidative stress were determined. Increases in plasma TOS and OSI levels and decreases in TAS levels were observed in both groups after surgery. The TOS level was significantly lower in the laparoscopic ovariectomy group compared with the open surgery group. Laparoscopic ovariectomy is a safe and beneficial surgical alternative to traditional ovariectomy with respect to oxidative stress status in dogs.

Effect of propofol on oxidative stress status in erythrocytes from dogs under general anaesthesia.

BACKGROUND: Alterations of the normal redox balance might be attributed to increase of plasma free-radical concentration and a disruption of the antioxidant defense system. One of the adverse effects of general anaesthetics is the exogen sources of reactive oxygen radicals that are responsible for several diseases. The purposes of the current study were to evaluate the effect of propofol on oxidative stress and to compare the differences between propofol induction only and induction plus continuous infusion on antioxidant status in dogs. FINDINGS: Beagle dogs were evaluated in the present study. The dogs were assigned randomly to receive three treatments in a crossover model. The three treatments were: group 1 (n = 9), 2% isoflurane; group 2 (n = 9), anaesthesia induced with an intravenous (IV) bolus dose of 6 mg/kg propofol and maintained with 1.5-2% isoflurane; group 3 (n = 9), total IV anaesthesia (induction with 6 mg/kg propofol, infusion with 0.6 mg/kg/min propofol). The results of this study show that dogs exposed to isoflurane had decreased antioxidant enzymes activities, whereas dogs injected with propofol had increased antioxidant enzymes activities. CONCLUSIONS: The results of this study showed that an infusion dose of propofol has antioxidant effects in dogs. These effects may be beneficial to patients in whom free radicals play a role in oxidative stress, such as those with ischemia. Further studies are needed to evaluate whether these antioxidant effects of the anaesthetic are of clinical value.

Erdosteine in renal ischemia-reperfusion injury: an experimental study in pigs.

The aim of the present study was to investigate the effect of erdosteine on renal reperfusion injury. Twelve male Landrace and Yorkshire mixed pigs were randomly divided into two groups: untreated control group (I/R), erdosteine treated group (I/R + erdosteine). Each group is composed of six pigs, and the pigs were unilaterally nephrectomized and their contralateral kidneys were subjected to 30 min of renal pedicle occlusion. The elevations of creatinine and blood urea nitrogen levels were lower in the treated group compared with the control group. The catalase activity and the glutathione peroxidase activity were higher in the erdosteine group. As a result, this study suggests that the erdosteine treatment has a role of attenuation of renal I/R injury recovery of renal function in pig.

Development and validation of a recombinant nucleocapsid protein-based ELISA for detection of the antibody to porcine reproductive and respiratory syndrome virus.

Three indirect enzyme-linked immunosorbent assays (iELISA) based on the North American like (NA-like), European like (EU-like) and co-expressed NA- and EU-like recombinant nucleocapsid proteins (N-protein) of porcine reproductive and respiratory syndrome virus (PRRSV) were validated for the detection of the antibodies in porcine sera. A total of 422 serum samples from unvaccinated pigs were tested. The cut-off value was optimized by a two-graph receiver operating characteristics analysis at a 95% confidence level. This assay was validated with Western blot analysis and IDEXX HerdChek ELISA. Cross-reactivity results showed that iELISA was PRRSV-specific. Repeatability tests revealed that the coefficients of variation of positive sera within and between runs were less than 10%. The results indicate that iELISA is simpler to produce and perform, time-saving and suitable for large scale surveys of PRRSV infection at low cost, and is potentially useful to evaluate the efficiency of various vaccines against PRRSV.

The effect of oculo-acupuncture on acute hepatic injury induced by carbon tetrachloride in dogs.

We investigated the therapeutic effect of oculo-acupuncture on dogs induced with acute hepatic injury. Hepatic injury was induced by intraperitoneal injection with carbon tetrachloride (CCl(4)) in 8 mongrel dogs (4 females and 4 males, aged 2 to 4 years). The dogs were divided into the control group (4 dogs) and the experimental group (4 dogs). The experimental group was treated with oculo-acupuncture at the liver/gallbladder regions plus the zhong jiao region of the eye after the induction of hepatic injury. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma glutamyl transpeptidase (GGT) activities were measured in both control and experimental groups. The serum AST, ALT, and GGT activities in the experimental group were decreased as compared to those in the control group. The significant differences were detected on the third day (AST, p < 0.05), second day (ALT, p < 0.05) and third day (GGT, p < 0.05) in the experimental group, respectively. Oculo-acupuncture alleviated acute liver damage induced by carbon tetrachloride in dogs was also confirmed by histopathological examination. We concluded that oculo-acupuncture at the liver/gallbladder regions plus the zhong jiao region was effective in the recovery of dogs from hepatic injury in a CCl(4)-induced model.

Attenuation of ischemia-reperfusion injury by ascorbic acid in the canine renal transplantation.

This study examined the effects of ascorbic acid on the attenuation of an ischemia-reperfusion (I/R) injury after a canine renal transplantation. Eight beagle dogs were subjected to a renal auto-transplantation followed by the administration of ascorbic acid (treatment group) and the same amount of vehicle (physiological saline, control group). Blood samples were collected from these dogs to perform the kidney function tests and the invasive blood pressure was measured in the renal artery at pre- and post-anastomosis. The antioxidant enzymes of level 72 h after the transplant were measured. The kidneys were taken for a histopathology evaluation at day 21. The kidney function tests showed a significant difference between the control and treatment group. The invasive blood pressure in the renal artery was similar in the groups. The activity of the antioxidant enzymes in the blood plasma was significant lower in the control group than in the treatment group. The histopathology findings revealed the treatment group to have less damage than the control group. The results of this study suggest that ascorbic acid alone might play a role in attenuating I/R injury and assist in the recovery of the renal function in a renal transplantation model.

Influence of ascorbic acid on BUN, creatinine, resistive index in canine renal ischemia-reperfusion injury.

Renal ischemia as a course of renal transplantation is a common cause of renal dysfunction as renal failure. The purpose of this study was to investigate the influence of ascorbic acid on blood urea nitrogen (BUN), creatinine (Cr) and resistive index (RI) for dog models with renal ischemia-reperfusion (I/R) injury. Renal ischemia was induced on 6 Beagle dogs. The left kidney was exposed to normothermic ischemia for a short period at 30 min followed by reperfusion. On the blood Cr level and RI, there was no significant difference comparing both groups. 14 days after I/R injury a significant reduction on the blood BUN level was observed in the vehicle group (34.06 mg/dl) compared to that of ischemia induced treated group (10.3 mg/dl) (p < 0.05). In conclusion, administration of ascorbic acid for renal ischemic-reperfusion injury had influence on blood BUN level, but it was not revealed the influence on blood Cr and RI.

Surgical correction of corneal dermoid in a dog.

A five-month-old female Shih-tzu puppy was presented for repair of congenital choristoma in left eye. The patient was suffered from chronic epiphora and ocular discharge during 3 months. On ophthalmic examination, left eye revealed hyperemia in conjunctiva of the temporal canthus due to choristoma with hair. At surgery, the choristoma invaded by stromal layer of the cornea, and extended to limbus and conjunctiva. Based on the anatomical location and histopathological features of the removed tissue, the choristoma was diagnosed as corneal dermoid.

Immobilization with ketamine HCl and tiletamine-zolazepam in cynomolgus monkeys.

To compare the effects of ketamine and tiletamine-zolazepam (TZ) drugs widely used for the chemical restraint and immobilization of primates, on various physiological parameters and blood gas values in cynomolgus monkeys (Macaca facicularis). Rectal temperature, heart rate, respiration rate and blood gas analysis were measured before treatment and at 1, 10, 20, 30, 40, 50 and 60 min after administration. Additionally, in both groups, induction and maintenance times were compared. Heart rate, respiration rate, rectal temperature, pH and pCO2 were not significant different in the two groups. However, pO2 in the ketamine-treated group was significantly lower at 30 and 40 min than in the TZ-treated group. The induction time was short in both groups, and the maintenance time was longer in the TZ-treated group (67.8-/+6.5 min) than in the ketamine-treated group (42.3-/+6.7 min). However, decreased rectal temperatures must be watched and prevented following TZ administration to cynomolgus monkeys. It was considered that ketamine may be useful for short duration anesthesia including handling, physical examination, blood sampling and TZ may be useful for prolonged anesthesia including minor surgery and other surgical procedure.