RESUMEN
Objective: To evaluate the antimicrobial resistance of non-O157 Shiga toxin-producing Escherichia coli (STEC) isolated from human cases. Methods: From 2011 to 2019, 33 non-O157 STEC strains recovered from diarrheal patients from 7 provinces/cities were collected, including Qinghai (1 isolate), Heilongjiang (1 isolate), Guangxi (2 isolates), Shandong (2 isolates), Guangdong (4 isolates), Henan (11 isolates), and Shanghai (12 isolates). Minimum inhibitory concentration (MIC) of 19 antimicrobials were tested by broth microdilution method; Oâ¶H serotypes, Multi-locus sequence typing (MLST) and antimicrobial resistance genes were determined by whole genome sequencing. Results: A total of 33 non-O157 STEC strains were typed into 19 Oâ¶H serotypes and 17 sequence types (STs), respectively. Ten strains were resistant to one or more antibiotics,of which five were multiple drug-resistant (MDR). The resistance rate of tetracycline was 30.3% (10 isolates), and azithromycin resistant strains were detected (12.12%, 4 isolates), but all strains were susceptible to carbapenems. All strains carried the blaEC gene, and the Extended-Spectrum ß-Lactamase (ESBL) genotype blaCTX-M-15 were detected (3.0%, 1 isolates). The fosA7 gene was firstly detected in non-O157 STEC strains. Conclusion: MDR, azithromycin resistance, and multiple drug resistance genes were detected in human-derived non-O157 STECs in many regions in China, but they were all susceptible to carbapenems. Our results might guide the clinical treatment of STEC infections.
Asunto(s)
Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Antibacterianos/farmacología , China , Farmacorresistencia Bacteriana/genética , Heces , Humanos , Tipificación de Secuencias Multilocus , Escherichia coli Shiga-Toxigénica/genéticaRESUMEN
Nitric oxide synthase (NOS) produces nitric oxide (NO) by catalyzing the conversion of l-arginine to l-citrulline, with the concomitant oxidation of nicotinamide adenine dinucleotide phosphate. Recently, various studies have verified the importance of NOS invertebrates and invertebrates. However, the NOS gene family in the oriental river prawn Macrobrachium nipponense is poorly understood. In this study, we cloned the full-length NOS complementary DNA from M. nipponense (MnNOS) and characterized its expression pattern in different tissues and at different developmental stages. Real-time quantitative polymerase chain reaction (RT-qPCR) showed the MnNOS gene to be expressed in all investigated tissues, with the highest levels observed in the androgenic gland (P < 0.05). Our results revealed that the MnNOS gene may play a key role in M. nipponense male sexual differentiation. Moreover, RT-qPCR revealed that MnNOS mRNA expression was significantly increased in post-larvae 10 days after metamorphosis (P < 0.05). The expression of this gene in various tissues indicates that it may perform versatile biological functions in M. nipponense.
Asunto(s)
Proteínas de Artrópodos/genética , Regulación del Desarrollo de la Expresión Génica , Óxido Nítrico Sintasa/genética , Palaemonidae/genética , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/metabolismo , Secuencia de Bases , China , Clonación Molecular , Conservación de los Recursos Naturales , ADN Complementario/genética , ADN Complementario/metabolismo , Embrión no Mamífero , Femenino , Larva/genética , Larva/crecimiento & desarrollo , Masculino , Óxido Nítrico Sintasa/metabolismo , Técnicas de Amplificación de Ácido Nucleico , Especificidad de Órganos , Palaemonidae/clasificación , Palaemonidae/crecimiento & desarrollo , Filogenia , Ríos , Alineación de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
Broad-Complex (BR-C) is an early ecdysone-responsive gene encoding a family of zinc-finger transcription factors. In this study, we isolated the full-length cDNA of a BR-C homolog from the testes of the oriental river prawn (Macrobrachium nipponense), according to established expressed sequence tag information, using the rapid amplification of cDNA ends technique. The homolog was designated as MnBR-C. The full-length cDNA of MnBR-C contained a 1095-bp open reading frame encoding a precursor protein of 365 amino acid residues. Comparative and bioinformatic analyses revealed that MnBR-C exhibited a high degree of homology with BR-C proteins, and contained the BTB and Zf-H2C2-2 domains. Real-time quantitative polymerase chain reaction (qPCR) analysis revealed that the MnBR-C expression level varied significantly in the developing embryo, postembryonic larva, and adult tissue. Real-time qPCR showed that the MnBR-C gene was expressed in all of the tissues investigated, with the highest level of expression in the brain. In addition, MnBR-C was more abundantly expressed in the testes than in the ovaries.
Asunto(s)
Clonación Molecular , Regulación del Desarrollo de la Expresión Génica , Palaemonidae/genética , Testículo/metabolismo , Factores de Transcripción/genética , Dedos de Zinc , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , ADN Complementario/genética , ADN Complementario/metabolismo , Embrión no Mamífero , Escherichia coli/genética , Escherichia coli/metabolismo , Femenino , Expresión Génica , Larva/genética , Larva/crecimiento & desarrollo , Larva/metabolismo , Masculino , Metamorfosis Biológica/genética , Sistemas de Lectura Abierta , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Palaemonidae/crecimiento & desarrollo , Palaemonidae/metabolismo , Estructura Terciaria de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Testículo/crecimiento & desarrollo , Factores de Transcripción/metabolismoRESUMEN
In this study, male-specific lethal 3 homolog (Mnmsl3) was cloned and characterized from the freshwater prawn Macrobrachium nipponense (Crustacea: Decapoda: Palaemonidae) by rapid amplification of cDNA ends. The deduced amino acid sequences of Mnmsl3 showed high-sequence homology to the insect Msl3 and contained a conserved chromatin organization modifier domain and an MORF4-related gene domain. Real-time quantitative reverse transcription-polymerase chain reaction showed that the Mnmsl3 gene was expressed in all the investigated tissues, with the highest level of expression in the testis. The expression level of Mnmsl3 between males and females was different in the gonad (testis or ovary), abdominal ganglion, and heart. The results revealed that the Mnmsl3 gene might play roles in regulating chromatin and in dosage compensation of M. nipponense. Real-time quantitative reverse transcription-polymerase chain reaction also revealed that Mnmsl3 mRNA expression was significantly increased in both 5 and 20 days post-larvae after metamorphosis, suggesting that Mnmsl3 plays complex and important roles in the early embryonic development and sex differentiation of M. nipponense.
Asunto(s)
Proteínas de Artrópodos/genética , Perfilación de la Expresión Génica , Palaemonidae/genética , Testículo/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/clasificación , Secuencia de Bases , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Femenino , Ganglión/metabolismo , Regulación del Desarrollo de la Expresión Génica , Larva/genética , Larva/crecimiento & desarrollo , Masculino , Metamorfosis Biológica/genética , Datos de Secuencia Molecular , Miocardio/metabolismo , Ovario/metabolismo , Palaemonidae/embriología , Palaemonidae/crecimiento & desarrollo , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ríos , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Factores SexualesRESUMEN
The gene female sterile homeotic (fsh) plays crucial roles in molecular function, including protein kinase activity and DNA binding, which are involved in biological processes such as terminal region determination and negative regulation of DNA-dependent transcription. Although fsh has been found in Drosophila melanogaster, little is known regarding its expression in crustaceans. In this study, a fsh gene homologue, designated as Mnfsh, was cloned and characterized from the testis of the oriental river prawn, Macrobrachium nipponense, by using EST analysis and the RACE approach for the first time. The full-length cDNA of Mnfsh was 2029 bp, consisting of a 5' UTR of 361 bp, a 3' UTR of 216 bp, and an ORF of 1452 bp encoding 484 amino acids. qRT-PCR analysis showed that the Mnfsh gene was expressed in the testis, ovary, muscle, heart, eyestalk, and abdominal ganglion, with the highest level of expression in the ovary and the lowest in the heart. qRT-PCR analyses showed that the expression levels of Mnfsh mRNA both significantly increased in the zoea stage, the VII larvae, and 1st day post-larvae after metamorphosis. In conclusion, the results of the present study indicate that Mnfsh is an arthropod fsh homologue and probably also plays important roles in embryogenesis, organogenesis, and morphological differentiation of M. nipponense.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica/genética , Palaemonidae/genética , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Proteínas de Unión al ADN/genética , Desarrollo Embrionario/genética , Expresión Génica/genética , Perfilación de la Expresión Génica , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
This study utilized high-throughput RNA sequencing technology to identify reproduction- and development-related genes of Macrobrachium nipponense by analyzing gene expression profiles of testis and ovary. More than 20 million 1 x 51-bp reads were obtained by Illumina sequencing, generating more than 7.7 and 11.7 million clean reads in the testis and ovary library, respectively. As a result, 10,018 unitags were supposed to be differentially expressed genes (DEGs) between ovary and testis. Compared to the ovary library, 4563 (45.5%) of these DEGs exhibited at least 6-fold upregulated expression, while 5455 (54.5%) DEGs exhibited at least 2-fold downregulated expression in the testis. The Gene Ontology (GO) enrichment analysis showed that 113 GO terms had potential molecular functions in reproduction. The Kyoto Encyclopedia of Genes and Genomes results revealed that the most important pathways may be relevant to reproduction and included 7 pathways. Forty-two genes were identified as reproduction-, development-, and sex-related genes based on GO classification and sequence comparison with other publications, including male reproductive-related LIM protein, spermatogenesis-associated protein, gametocyte-specific factor 1, VASA-like protein, vitellogenin, sex-determining protein fem-1, and other potential candidates. These results will advance research in the field of molecular genetics in M. nipponense and offer a valuable resource for further research related to reproduction in crustaceans.
Asunto(s)
Ovario/fisiología , Palaemonidae/genética , Reproducción/genética , Testículo/fisiología , Animales , Femenino , Perfilación de la Expresión Génica , Ontología de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Masculino , Redes y Vías Metabólicas , Ovario/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Testículo/metabolismoRESUMEN
The oriental river prawn, Macrobrachium nipponense, is an important aquaculture species in China. The androgenic gland produces hormones that play crucial roles in the differentiation of crustaceans to the male sex. MicroRNA (miRNA) post-transcriptionally regulates many protein-coding genes, influencing important biological and metabolic processes. However, currently, there is no published data identifying miRNA in M. nipponense. In this study, we identified novel miRNA in the androgenic gland of M. nipponense. Using the high-throughput Illumina Solexa system, 1077 miRNA were identified from small RNA libraries by aligning with the de novo androgenic gland transcriptome of M. nipponense (obtained from RNA-Seq) and the sequences in the miRBase21 database. A total of 8,248, 76,011, and 78,307 target genes were predicted in the EST and SRA sequences provided in the NCBI database, and the androgenic gland transcriptome of M. nipponense, respectively. Some potential sex-related miRNA were identified based on the function of the predicted target genes. The results of our study provide new information regarding the miRNA expression in M. nipponense, which could be the basis for further genetic studies on decapod crustaceans.
Asunto(s)
MicroARNs/genética , Palaemonidae/genética , Interferencia de ARN , ARN Mensajero/genética , Ríos , Animales , Biología Computacional/métodos , Dosificación de Gen , Regulación de la Expresión Génica , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Factores SexualesRESUMEN
To assess the genetic status of this species, the genetic diversity of wild Macrobrachium nipponense from seven geographic locations in the Yellow River basin were investigated using 20 polymorphic microsatellite DNA loci. The genetic diversity between populations was indicated by the mean number of alleles per locus and mean observed heterozygosity (H) and the expected H, which was arranged from 2 to 10, from 0.4705 to 0.5731, and from 0.5174 to 0.6146, respectively. Hardy-Weinberg equilibrium analysis indicated that a deficiency of heterozygotes existed in all seven populations. Both the F(ST) and AMOVA analyses showed that there is significant difference on population differentiation among populations. The UPGMA clustering tree demonstrated that their close relationship is consistent with their geographic proximity. The data suggest that this Yellow River population has a wide genetic base that is suitable for breeding.
Asunto(s)
Repeticiones de Microsatélite , Palaemonidae/genética , Polimorfismo Genético , Alelos , Animales , Marcadores Genéticos , Heterocigoto , MutaciónRESUMEN
In this study, two Sxl gene homologs, designated as Mnsxl1 and Mnsxl2, were cloned and characterized from the freshwater prawn Macrobrachium nipponense by rapid amplification of cDNA ends. The deduced amino acid sequences of Mnsxl1 and Mnsxl2 showed high sequence homology to the insect Sxl and contained conserved domains in two RNA-binding motifs. Real-time quantitative reverse transcription-polymerase chain reaction (RT-QPCR) showed that the Mnsxl1 and Mnsxl2 genes were expressed in all investigated tissues, with the highest level of expression in the intestine and liver. RT-QPCR also revealed that Mnsxl1 and Mnsxl2 mRNAs expressions were both significantly increased at 5 and 20 days post-larvae after metamorphosis. Thus, the results of the present study imply that Mnsxl1 and Mnsxl2 play complex and important roles in the sex differentiation of M. nipponense.