Investigation of Toxoplasma infection in zoo animals using multispecies ELISA and GRA7 nested PCR.

BACKGROUND: Toxoplasma is an obligate intracellular protozoan that causes an important zoonotic disease with a worldwide distribution. Felids are the definitive hosts of this parasite, while virtually all warm-blooded animals, including birds, serve as intermediate hosts. Four ring-tailed lemurs (Lemur catta) in the Taipei Zoo died of acute Toxoplasma infection in June 2019. Since then, Toxoplasma has occasionally been identified in this Zoo during necropsy of dead animals and PCR of animal blood samples. Therefore, a general survey of Toxoplasma infection in animals in the Zoo seems to be needed. METHODS AND RESULTS: An indirect multispecies ELISA was used for the first time to screen for Toxoplasma infection in 326 serum samples collected from 75 species of animals. The infection rate of Toxoplasma was 27% (88/326). A commercial latex agglutination (LAT) assay was used to re-examine the samples with doubtful and uncertain ELISA results (151 samples from 42 species). The infection rate increased to 36.2% (118/326), and the indirect multispecies ELISA appeared to be applicable to 31 of 75 species animals included in this study. Nested PCR assays targeting the dense granule protein 7 (GRA7) gene and B1 gene were also used to detect Toxoplasma in DNA samples extracted from 10 liver or blood specimens from 8 animals. GRA7 gene fragments were amplified from 8 samples from 7 animals, while B1 gene fragments were amplified from only 4 samples from 4 animals. From the B1 nested PCR and the sequence data of GRA7 fragments amplified from infectious specimens, the animals in the Zoo were speculated to have been infected by at least three different Toxoplasma variants. CONCLUSIONS: According to the serological investigation, we speculated that over one-third (36.2%) of animals in Taipei Zoo presented the infection of Toxoplasma, and the indirect multispecies ELISA we used can be applied to detect Toxoplasma infection in 31 animal species included in this study. Sequence analysis revealed that at least three Toxoplasma variants were infecting the animals of Taipei Zoo.

[A high level of high-density lipoprotein cholesterol is a protective factor against transplant renal artery stenosis].

OBJECTIVE: To investigate the factors associated with the occurrence of transplant renal artery stenosis (TRAS). METHODS: A retrospective analysis was conducted in 26 recipients who developed TRAS and 40 concurrent renal recipients without TRAS. We also conducted a nested case-control study in 14 patients with TRAS (TRAS-SD group) and another 14 non-TRAS recipients who received the allograft from the same donor (non-TRAS-SD group). RESULTS: Compared with those in the concurrent recipients without TRAS, acute rejection (AR) occurred at a significantly higher incidence (P=0.004) and the warm ischemia time (WIT) was significantly longer (P=0.015) and the level of high?density lipoprotein cholesterol (HDL--C) significantly lower (P=0.009) in the recipients with TRAS. Logistic regression analysis suggested that AR (P=0.007) and prolonged WIT (P=0.046) were risk factors of TRAS while HDL-C (P=0.022) was the protective factor against TRAS. In recent years early diagnosis of TRAS had been made in increasing cases, the interval from transplantation to TRAS diagnosis became shortened steadily, and the recipients tended to have higher estimated glomerular filtration rate at the time of TRAS diagnosis. CONCLUSION: Apart from the surgical technique, AR and prolonged WIT are also risk factors of TRAS while a high HDL-C level is the protective factor against TRAS. The improvement of the diagnostic accuracy by ultrasound is the primary factor contributing to the increased rate of early TRAS diagnosis in recent years.

[Early intervention of BK virus replication promotes stabilization of renal graft function].

OBJECTIVE: To investigate the optimal time window for intervention of BK virus (BKV) replication and its effect on the outcomes of kidney transplant recipients (KTRs). METHODS: A retrospective analysis of the clinical data and treatment regimens was conducted among KTRs whose urine BKV load was ≥1.0×104 copies/mL following the operation between April, 2000 and April, 2015. KTRs with urine BKV load <1.0×104 copies/mL matched for transplantation time served as the control group. RESULTS: A total of 54 recipients positive for urine BKV were included in the analysis. According to urine BKV load, the recipients were divided into 3 groups: group A with urine BKV load of 1.0×104-1.0×107 copies/mL (n=22), group B with urine BKV load >1.0×107 copies/mL (n=24), and group C with plasma BKV load ≥1.0×104 copies/mL (n=8); 47 recipients were included in the control group. During the follow-up for 3.2-34.5 months, the urine and plasma BKV load was obviously lowered after intervention in all the 54 BKV-positive recipients (P<0.05). Eighteen (81.82%) of the recipients in group A and 19 (79.17%) in group B showed stable or improved estimated glomerular filtration rate (eGFR) after the intervention; in group C, 4 recipients (50%) showed stable eGFR after the intervention. In the last follow-up, the recipients in groups A and B showed similar eGFR with the control group (P>0.05), but in group C, eGFR was significantly lower than that of the control group (P=0.001). The recipients in group A and the control group had the best allograft outcome with stable or improved eGFR. CONCLUSION: Early intervention of BKV replication (urine BKV load ≥1.0×104 copies/mL) in KTRs with appropriate immunosuppression reduction can be helpful for stabilizing the allograft function and improving the long-term outcomes.