Effects of Catecholamine Stress Hormones Norepinephrine and Epinephrine on Growth, Antimicrobial Susceptibility, Biofilm Formation, and Gene Expressions of Enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) is a significant contributor to diarrhea. To determine whether ETEC-catecholamine hormone interactions contribute to the development of diarrhea, we tested the effects of catecholamine hormones acting on ETEC in vitro. The results showed that in the presence of norepinephrine (NE) and epinephrine (Epi), the growth of 9 out of 10 ETEC isolates was promoted, the MICs of more than 60% of the isolates to 6 antibiotics significantly increased, and the biofilm formation ability of 10 ETEC isolates was also promoted. In addition, NE and Epi also significantly upregulated the expression of the virulence genes feaG, estA, estB, and elt. Transcriptome analysis revealed that the expression of 290 genes was affected by NE. These data demonstrated that catecholamine hormones may augment the diarrhea caused by ETEC.

The prevalence, genetic diversity and evolutionary analysis of cachavirus firstly detected in northeastern China.

Canine cachavirus is a novel parvovirus belonging to the genus Chaphamaparvovirus that was first detected in dogs in the United States. However, our knowledge of the prevalence and genetic characteristics of cachavirus is relatively limited. In this study, 325 canine fecal specimens collected from healthy and diarrheic dogs in northeastern China were screened with PCR. Twenty-two of the 325 (6.8%) samples were positive for cachavirus. The diarrhea samples showed high viral coinfection rates, and we detected coinfections with canine astrovirus (CaAstV) and cachavirus for the first time. A sequence analysis revealed that the Chinese cachavirus strains have point mutations in four consecutive amino acid codons relative to the original American strain. A codon usage analysis of the VP1 gene showed that most preferred codons in cachavirus were A- or T-ending codons, as in traditional canine parvovirus 2. A co-evolutionary analysis showed that cachavirus has undergone cospeciation with its hosts and has been transmitted among different host species. Our findings extend the limited cachavirus sequences available, and provide detailed molecular characterization of the strains in northeastern China. Further epidemiological surveillance is required to determine the significance and evolution of cachavirus.

Multiple genotypes infection and molecular characterization of Torque teno neovison virus: A novel Anelloviridae of mink in China.

A novel Torque teno neovison virus (TTVs) was identified in specimens collected from dead mink during an outbreak of the Aleutian mink disease virus. Eighteen complete genomic sequences were obtained, ranging from 2109 to 2158 nucleotides in length and consisting of an untranslated region and three open reading frames. The genomic organization of mink TTVs is similar to previously reported anelloviruses. However, the deduced amino acid sequence of its ORF1 protein shows genetic diversity compared to related anelloviruses, suggesting that it represents a putative new species within the Anelloviridae family. This study provides a detailed molecular characterization of the novel mink anelloviruses, including its codon usage pattern, origin, and evolution. Analysis of the viral genomic sequences reveals the existence of multiple genotypes of co-infection. Principal component analysis and phylogenetic trees confirm the coexistence of multiple genotypes. Furthermore, the codon usage analyses indicate that mink TTVs have a genotype-specific codon usage pattern and show a low codon usage bias. Host-specific adaptation analysis suggests that TTVs are less adapted to mink. The possible origin and evolutionary history of mink TTVs were elucidated. Mink TTVs was genetically closely related to giant panda anellovirus, representing a new species. The observed incongruence between the phylogenetic history of TTVs and that of their hosts suggests that the evolution of anellovirus is largely determined by cross-species transmission. The study provides insights into the co-infection and genetic evolution of anellovirus in China.

Genetic changes and evolutionary analysis of canine circovirus.

Canine circovirus (canineCV) has been found to be associated with vasculitis, hemorrhage, hemorrhagic enteritis, and diarrhea of canines. CanineCV, like other circoviruses, may also be associated with lymphoid depletion and immunosuppression. This circovirus has been detected worldwide in different countries and species. Recombination and mutation events in the canineCV genome have been described, indicating that the virus is continuing to evolve. However, the origin, codon usage patterns, and host adaptation of canineCV remain to be studied. Here, the coding sequences of 93 canineCV sequences available in the GenBank database were used for analysis. The results showed that canineCV sequences could be classified into five genotypes, as confirmed by phylogenetic and principal component analysis (PCA). Maximum clade credibility (MCC) and maximum-likelihood (ML) trees suggested that canineCV originated from bat circovirus. G/T and A/C nucleotide biases were observed in ORF1 and ORF2, respectively, and a low codon usage bias (CUB) was found in canineCV using an effective number of codon (ENC) analysis. Correlation analysis, ENC plot analysis and neutrality plot analysis indicated that the codon usage pattern was mainly shaped by natural selection. Codon adaptation index (CAI) analysis, relative codon deoptimization index (RCDI) analysis, and similarity index (SiD) analysis revealed a better adaption to Vulpes vulpes than to Canis familiaris. Furthermore, a cross-species transmission hypothesis that canineCV may have evolved from bats (origin analysis) and subsequently adapted to wolves, arctic foxes, dogs, and red foxes, was proposed. This study contributes to our understanding of the factors related to canineCV evolution and host adaption.

Genetic and evolutionary analysis of emerging HoBi-like pestivirus.

HoBi-like pestivirus, an emerging species within the Pestivirus genus, is an important pathogen associated with a variety of clinical manifestations of ruminants, especially cattle. HoBi-like pestiviruses were identified in several countries and from different hosts, and raised concerns with regard to their acute and persistent infections, which is implicated in economic losses for cattle farmers. However, the transmission path, codon usage bias, and host adaptation of the virus has not been studied. Hence, we performed the analysis the spatio-temporal transmission based on the available 5'-UTR sequences of HoBi-like pestivirus, and then conducted codon analysis of the complete coding sequence of the virus. The results show the virus appeared in 1952 (95% HPD: 1905-1985) and may have originated in India. In addition, Italy is the hub for the spread of the virus. Moreover, six potential recombination events and two complex recombination events were discovered. Analysis of codon usage patterns revealed that the effective number of codon (ENC) values with an average of 50.85, and the codon usage bias is greatly affected by natural selection, which is different from the previous BVDV-1, 2. Finally, codon adaptation index (CAI) analysis shows that pigs may be the potential origin species of the HoBi-like pestivirus. These findings will contribute to more effective control of the spread of the virus, extend the knowledge about the genetic and evolutionary features of HoBi-like viruses and provide some information for vaccine research.