Genomic and phylogenetic analysis of avian polyomaviruses isolated from parrots in Taiwan.

Avian polyomavirus (APV) is a non-enveloped virus with a circular double-stranded DNA genome approximately 5000 bp in length. APV was first reported in fledgling budgerigars (Melopsittacus undulatus) as the causative agent of budgerigar fledgling disease, resulting in high parrot mortality rates in the 1980s. This disease has been observed worldwide, and APV has a wide host range including budgerigars, cockatoos, lorikeets, lovebirds, and macaws. Twenty APV isolates have been collected from healthy and symptomatic parrots in Taiwan from 2015 to 2019. These isolates were then amplified via polymerase chain reaction, after which the whole genomes of these isolates were sequenced. The overall APV-positive rate was 14.2%, and the full lengths of the APV Taiwan isolates varied from 4971 to 4982 bps. The APV genome contains an early region that encodes two regulatory proteins (the large tumor antigen (Large T-Ag) and the small tumor antigen (Small t-Ag)) and a late region which encodes the capsid proteins VP1, VP2, VP3, and VP4. The nucleotide identities of the VP1 and VP4 genes ranged from 98.7 to 100%, whereas the nucleotide sequence of the Large T-Ag gene had the highest identity (99.2-100%) relative to other APV isolates from the GenBank database. A phylogenetic tree based on the whole genome demonstrated that the APV Taiwan isolates were closely related to Japanese and Portuguese isolates. Recombination events were analyzed using the Recombination Detection Program version 4 and APV Taiwan isolate TW-3 was identified as a minor parent of the APV recombinants. In this study, we first reported the characterization of the whole genome sequences of APV Taiwan isolates and their phylogenetic relationships with all APV isolates available in the GenBank database.

Ultrastructural Characterization of Porcine Growing and In Vitro Matured Oocytes.

This study aimed to investigate ultrastructural changes of growing porcine oocytes and in vitro maturated oocytes. Light microscopy was used to characterize and localize the primordial, primary, secondary, and tertiary follicles. During oocyte growth and maturation, the morphology of mitochondria was roundish or ovoid in shape depending on the differentiation state, whereas their mean diameters oscillated between 0.5 and 0.7 µm, respectively, from primary and secondary follicles. Hooded mitochondria were found in the growing oocytes of the tertiary follicles. In addition to the pleomorphism of mitochondria, changes in the appearance of lipid droplets were also observed, along with the alignment of a single layer of cortical granules beneath the oolemma. In conclusion, our study is apparently the first report to portray morphological alterations of mitochondria that possess the hooded structure during the growth phase of porcine oocytes. The spatiotemporal and intrinsic changes during oogenesis/folliculogenesis are phenomena at the ultrastructural or subcellular level of porcine oocytes, highlighting an in-depth understanding of oocyte biology and impetus for future studies on practical mitochondrion replacement therapies for oocytes.

The phylogenetic and recombinational analysis of beak and feather disease virus Taiwan isolates.

Beak and feather disease virus (BFDV) is an avian circovirus, and it has a single-stranded DNA genome. It causes a fatal disease in parrots called psittacine beak and feather disease (PBFD). After screening of samples collected from Taiwan using PCR, complete genome sequences of isolates from 21 samples from various species of parrot were obtained. The nucleotide sequences of the replication-associated protein gene (rep) and the amino acid sequences of the replication-associated protein (Rep) were more conserved than the nucleotide sequences of the capsid protein gene (cp) and the amino acid sequences of the capsid protein (CP). In Bayesian phylogenetic analysis, the topology of the complete genome sequence was similar to that of the rep gene alone. Recombination events were identified in Taiwan isolates. Recombination hot spots were mainly located in the intergenic region between the 3' ends of the rep and cp genes and at the 5' end of the cp gene. The 5' end and the middle of the rep gene were found to be recombination cold spots. Despite the overall negative selection that was observed for the rep and cp genes, one and 18 positive selected sites were found for the rep and cp gene, respectively.

Purification and characterization of hemagglutinating proteins from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea).

Hemagglutinating proteins (HAPs) were purified from Poker-chip Venus (Meretrix lusoria) and Corbicula clam (Corbicula fluminea) using gel-filtration chromatography on a Sephacryl S-300 column. The molecular weights of the HAPs obtained from Poker-chip Venus and Corbicula clam were 358 kDa and 380 kDa, respectively. Purified HAP from Poker-chip Venus yielded two subunits with molecular weights of 26 kDa and 29 kDa. However, only one HAP subunit was purified from Corbicula clam, and its molecular weight was 32 kDa. The two Poker-chip Venus HAPs possessed hemagglutinating ability (HAA) for erythrocytes of some vertebrate animal species, especially tilapia. Moreover, HAA of the HAP purified from Poker-chip Venus was higher than that of the HAP of Corbicula clam. Furthermore, Poker-chip Venus HAPs possessed better HAA at a pH higher than 7.0. When the temperature was at 4°C-10°C or the salinity was less than 0.5‰, the two Poker-chip Venus HAPs possessed better HAA compared with that of Corbicula clam.

Effects of nanogold on the alleviation of carbon tetrachloride-induced hepatic injury in rats.

Gold particles have been used in complementary medicine for decades, and many beneficial effects have been reported. Our present study sought to evaluate the therapeutic effects of nanogold in carbon tetrachloride (CCl4)-injured liver of rats. Male SD rats were subjected to liver injury induction by CCl4, then the rats were fed with zero to high dose (0, 1, 5 or 10 ppm) of nanogold water every day for 4 weeks. Biochemical analyses on liver functions were then performed to evaluate the therapeutic effects of nanogold. Our results revealed that gold nanoparticles lowered serum aspartate aminotransaminase (AST) and alanine aminotransferase and exerted serum total protein-recovering effects, which might be partially associated with the elevation of anti-inflammatory cytokine IL-10 level. In addition, serum triglyceride level fell after continuous ingestion of nanogold. Finally, the experimental animals recovered body weight after 4 weeks of nanogold ingestion. This is the first report indicating inflammation alleviating effects of nanogold on hepatic injury.

Lactococcus lactis subsp. lactis infection in Bester sturgeon, a cultured hybrid of Huso huso × Acipenser ruthenus, in Taiwan.

Approximately 5300 hybrid sturgeons with an average body weight of 600-800 g were farmed in 3 round tankers measuring 3m in diameter each containing 28,000 L of aerated groundwater. According to the owner's description, the diseased fish had anorexia, pale body color, and reddish spots on the abdomen. The morbidity and lethality rates in this outbreak were about 70% (3706/5300) and 100% (3706/3706), respectively. The clinical examination revealed enteritis, enlarged abdomen, and rapid respiration rate. The gross findings revealed a volume of about 4 mL of ascites. The histopathological examination showed multiple massive, hemorrhagic or coagulative necrotic foci in the liver and spleen. Furthermore, there was diffuse infiltration of glycogen in hepatic cells, and a few polymorphonuclear and mononuclear leucocytes were observed surrounding the spleen. Some bacterial clumps were noted around the necrotic foci. We also observed that there was moderate to severe, acute, multifocal, coagulative necrosis in the renal parenchyma, with some necrotic foci present beneath the margin of the kidney. Additionally, multifocal, coagulative necrosis was found in the pancreas. Results of microbiologic examinations, including biochemical characteristics, PCR amplification of 16S rRNA gene, sequencing and comparison, and phylogenetic analysis, revealed the pathogen of this infection was Lactococcus lactis subsp. lactis, and based on the results of an antimicrobial agent sensitivity test the bacterium was only sensitive to ampicillin and florfenicol. Additionally, results of in vivo experimental infections in hybrid tilapia showed that 1×10(8) and 1×10(9) CFU/mL of our isolate caused death in all fish and LD(50) values ranged from 10(2) to 10(5) CFU/mL. To the best of the authors' knowledge, this is the first reported case of Lactococcus lactis subsp. lactis infection in hybrid sturgeon.

Relationship between age, plasma renin activity, and renal resistive index in dogs.

The renal resistive index (RI) value of 0.73 has been proposed as the upper limit in normal adult dogs. In humans, changes in RI with age are associated with plasma renin activity. There are relatively few equivalent reference data for dogs. We obtained reference RI data from 22 clinically healthy dogs <4 months of age and 33 healthy dogs between 4 months and 7 years of age. An association between the RI and plasma renin activity was investigated. The mean RI in the older dogs was 0.65 +/- 0.05 vs. 0.75 +/- 0.05 in dogs <4 months of age. The mean plasma renin activity in the older dogs was 1.18 +/- 1.03 vs. 4.23 +/- 3.09 ng/ml/h in dogs <4 months of age. There was a weak linear relationship between the RI and plasma renin activity (r2 = 0.280, P < 0.01) in dogs <4 months of age. Also in these younger dogs, RI was negatively correlated with age (r2 = 0.682, P < 0.01). The RI was higher in dogs <4 months of age than in older dogs. Therefore, the mean renal RI is slightly higher in young dogs than reported for an older population and interpretation of the RI must include an assessment of patient age.

The effects of different anesthetic agents on short electroretinography protocol in dogs.

The purpose of this article was to investigate the effects of sedatives and general anesthetics, such as tiletamine-zolazepam, medetomidine, and isoflurane on the short ERG protocol. Six healthy mongrel dogs were assessed by a convenient short ERG protocol with the owners' consent. The amplitudes of a-wave and b-wave, as well as the implicit time of ERG under different anesthesia statuses, were recorded and analyzed. The amplitudes of ERG waves were not significantly different between tiletamine-zolazepam and medetomidine groups, except in b-wave after 5 min dark adaptation (140 +/- 42 microV in tiletamine-zolazepam and 101 +/- 32 microV in medetomidine, p<0.01). The amplitude of ERG recorded in isoflurane (5 +/- 3 microV of a-wave and 12 +/- 6 microV of b-wave under light adaptation; 41 +/- 19 microV of b-wave after 1 min dark adaptation; 28 +/- 15 microV of a-wave and 58 +/- 32 microV of b-wave after 5 min dark adaptation) were significantly different from tiletamine-zolazepam (8 +/- 2 microV of a-wave and 24 +/- 9 microV of b-wave under light adaptation; 117 +/- 44 microV of b-wave after 1 min dark adaptation; 59 +/- 18 microV of a-wave and 140 +/- 42 microV of b-wave after 5 min dark adaptation), except in a-wave after 1 min dark adaptation (39 +/- 13 microV in tiletamine-zolazepam and 34 +/- 17 microV in isoflurane). Comment-General anesthesia had significantly lower amplitudes in the dark-adapted group compared with the sedation group. Therefore, tiletamine-zolazepam is a desirable choice for the short ERG protocol in dogs.

Antibiotic susceptibility and prevalence of erythromycin ribosomal methylase gene, erm(B) in Streptococcus spp.

The aim of this study was to investigate drug resistance and the genetic relatedness of erythromycin-resistant Streptococcus spp. from different animals and humans in Taiwan. Cumulatively, 248 isolates were collected from 15 animal species and human patients and the susceptibilities of the isolates to six antimicrobial agents including azithromycin (AZI), clarithromycin (CLAR), erythromycin (ERY), spiramycin (SPIR), amoxicillin (AMO), and enrofloxacin (ENRO) were determined by the agar dilution method. The results indicated that resistance among the 248 strains was highest for SPIR, followed by ENRO, CLAR, ERY, AZI, and AMO. The most common resistotypes of the isolates from mammals and aquatic animals were AZI-CLAR-ERY-SPIR (27.5%) and SPIR (55.1%), respectively. The presence of ERY-resistant genes was confirmed by PCR. The erm gene was amplified from 28 isolates (20.6%) by PCR for further investigation. The predominant erm gene in the ERY-resistant isolates was the erm(B) gene. The phylogenetic analysis of the erm(B) gene results indicated that there was a close genetic relationship among all the strains but the genotypic clusters did not show clear segregation of the isolates according to the source or region.