Deciphering Multidrug-Resistant Plasmids in Disinfection Residual Bacteria from a Wastewater Treatment Plant

Current disinfection processes pose an emerging environmental risk due to the ineffective removal of antibiotic-resistant bacteria, especially disinfection residual bacteria (DRB) carrying multidrug-resistant plasmids (MRPs). However, the characteristics of DRB-carried MRPs are poorly understood. In this study, qPCR analysis reveals that the total absolute abundance of four plasmids in postdisinfection effluent decreases by 1.15 log units, while their relative abundance increases by 0.11 copies/cell compared to investigated wastewater treatment plant (WWTP) influent. We obtain three distinctive DRB-carried MRPs (pWWTP-01-03) from postdisinfection effluent, each carrying 9-11 antibiotic-resistant genes (ARGs). pWWTP-01 contains all 11 ARGs within an ∼25 Kbp chimeric genomic island showing strong patterns of recombination with MRPs from foodborne outbreaks and hospitals. Antibiotic-, disinfectant-, and heavy-metal-resistant genes on the same plasmid underscore the potential roles of disinfectants and heavy metals in the coselection of ARGs. Additionally, pWWTP-02 harbors an adhesin-type virulence operon, implying risks of both antibiotic resistance and pathogenicity upon entering environments. Furthermore, some MRPs from DRB are capable of transferring and could confer selective advantages to recipients under environmentally relevant antibiotic pressure. Overall, this study advances our understanding of DRB-carried MRPs and highlights the imminent need to monitor and control wastewater MRPs for environmental security.

Identification of Candidate Genes Associated with Yak Body Size Using a Genome-Wide Association Study and Multiple Populations of Information

Yaks have evolved several breeds or genetic resources owing to their geographical and ecological environment, and investigating the genetic construction of body size among breeds is key for breeding. Here, a genome-wide association study (GWAS) was performed for five body size traits in 31 yak breeds and genetic resources. The information from clustering individuals according to their habitats was used for kinship grouping in the compressed mixed linear model (CMLM). We named this approach the pCMLM method. A total of 3,584,464 high-quality single nucleotide polymorphisms (SNPs) were obtained, and six markers were found to be significantly associated with height by pCMLM. Four candidate genes, including FXYD6, SOHLH2, ADGRB2, and OSBPL6, were identified. Our results show that when CMLM cannot identify optimal clustering groups, pCMLM can provide sufficient associated results based on population information. Moreover, this study provides basic information on the gene localization of quantitative traits of body size among yak breeds.

A New Type of Allodiploid Hybrids Derived From Female Megalobrama amblycephala × Male Gobiocypris rarus

Distant hybridization can combine whole genomes from parent species and result in changes in the phenotypes and genotypes in hybrids. The characteristics of many hybrid fishes with even number of chromosomes have been reported, but the hybrids with odd number chromosomes are rarely reported. Blunt snout bream (Megalobrama amblycephala, BSB, 2n = 48) and rare gudgeon (Gobiocypris rarus, RG, 2n = 50) belong to two different subfamilies and have quite different biological characteristics. In this study, we obtain the hybrids (BR) derived from the inter-subfamily hybridization of female BSB and male RG. We investigate the fertilization rate, hatching rate, morphological traits, chromosomal numbers, DNA content, growth rates, and 5S rDNA in the BR. The results show that the BR is an allodiploid fish with 49 chromosomes, and all the measurable traits are significantly different (p < 0.05) among BR, BSB, and BR. Interestingly, the upper part of the BR body color is similar to BSB (gray), the lower part of the BR body color is similar to RG (light yellow), and the BR inherits a unique light yellow wide longitudinal band from the RG. Furthermore, the BR has a fast growth rate compared with RG. The 5S rDNA of the BR inherits the specific bands of its parental 5S rDNA respectively and has some mutations, which show obvious recombination, heredity, and variability in BR. This study will be of great significance in fish genetic breeding.

Molecular Characterization and Expression Profiles of the Ovine LHβ Gene and Its Association with Litter Size in Chinese Indigenous Small-Tailed Han Sheep

Simple Summary

Litter size is one of the most important reproductive traits in sheep, and the luteinizing hormone beta polypeptide (LHβ) plays an important role in mammalian follicular development. In this study, we cloned and analyzed the cDNA sequence of the ovine LHβ gene, and the expression patterns of LHβ were determined. Furthermore, the synonymous mutation g.727C > T detected in the LHβ gene was confirmed to be significantly associated with litter size (p < 0.01). These findings support LHβ g.727C > T as a genetic marker for litter size in sheep.

Abstract

The luteinizing hormone beta polypeptide (LHβ) is a glycoprotein hormone secreted by basophilic granular cells of the adenohypophysis, and plays an important role in mammalian follicular development. In this study, we cloned and analyzed the cDNA sequence of the ovine LHβ gene. RT-qPCR analysis showed that ovine LHβ was widely expressed in tissues, with significantly higher expression in the hypophysis than that in other tissues (heart, liver, spleen, lung, kidney, rumen, duodenum, muscle, fat, hypothalamus, and sex glands) (p < 0.01). Hypophyseal expression of LHβ mRNA in lamb increased with age and reached a peak at 70 days, although a slight decrease was observed at 84 days of age. In addition, the synonymous mutation g.727C > T detected in the LHβ gene was confirmed to be significantly associated with the litter size (p < 0.01). Ewes carrying the TT genotype produced more lambs than those carrying the TC and CC genotypes (0.42 and 0.39 per delivery, respectively; p < 0.05). Our results confirm the association of ovine LHβ with litter size in Small-Tailed Han Sheep and implicate LHβ as a candidate for improving reproductive traits in agricultural sheep breeding programs.

Aspergillus penicillioides Speg. Implicated in Keratomycosis

The aim of the study was mycological examination of ulcerated corneal tissues from an ophthalmic patient. Tissue fragments were analyzed on potato-glucose agar (PDA) and maltose (MA) (Difco) media using standard laboratory techniques. Cultures were identified using classical and molecular methods. Macro- and microscopic colony morphology was characteristic of fungi from the genus Aspergillus (restricted growth series), most probably Aspergillus penicillioides Speg. Molecular analysis of the following rDNA regions: ITS1, ITS2, 5.8S, 28S rDNA, LSU and β-tubulin were carried out for the isolates studied. A high level of similarity was found between sequences from certain rDNA regions, i.e. ITS1-5.8S-ITS2 and LSU, what confirmed the classification of the isolates to the species A. penicillioides. The classification of our isolates to A. penicillioides species was confirmed also by the phylogenetic analysis.

The aim of the study was mycological examination of ulcerated corneal tissues from an ophthalmic patient. Tissue fragments were analyzed on potato-glucose agar (PDA) and maltose (MA) (Difco) media using standard laboratory techniques. Cultures were identified using classical and molecular methods. Macro- and microscopic colony morphology was characteristic of fungi from the genus Aspergillus (restricted growth series), most probably Aspergillus penicillioides Speg. Molecular analysis of the following rDNA regions: ITS1, ITS2, 5.8S, 28S rDNA, LSU and β-tubulin were carried out for the isolates studied. A high level of similarity was found between sequences from certain rDNA regions, i.e. ITS1-5.8S-ITS2 and LSU, what confirmed the classification of the isolates to the species A. penicillioides. The classification of our isolates to A. penicillioides species was confirmed also by the phylogenetic analysis.

[Clinical and genetic features of Chinese kindreds with Van der Woude syndrome caused by interferon regulatory factor 6 mutation]

OBJECTIVE

This study aimed to investigate the clinical phenotype and genetic characteristics of Chinese families with Van der Woude syndrome (VWS).

METHODS

Clinical manifestations between 14 families and within each family were recorded. Possible inheritance modes and pathogenic genes were analyzed. Phenotypic distribution and gene frequencies were calculated.

RESULTS

Of the pedigrees investigated, an autosomal dominant inheritance pattern was suggested. All patients had typical symptoms. The pathogenic gene was interferon regulatory factor 6 (IRF6). Phenotypic distribution frequencies were as follows: lip pits (91.9%), cleft lip and/or palate (73.0%), and hyperdontia (8.1%). There were significant differences in clinical phenotypes among individuals of different families and individuals of the same family.

CONCLUSIONS

VWS in a Chinese population was dominantly inherited with high penetrance and variable expressivity. The pathogenic gene was IRF6. VWS in a Chinese population was genotyped as VWS1.

Identification and genetic characterization of porcine circovirus type 3 in China

A novel circovirus called porcine circovirus type 3 (PCV3) was recently reported to exist in the USA. This circovirus is associated with porcine dermatitis, nephropathy syndrome and reproductive failure. This study reports on the first identification, widely epidemic, different phylogenetic clusters, potential role in sow reproductive failure and possible origins of PCV3 in China.