Background: The D antigen is the most important and immunogenic antigen of the Rh blood group;its correct screening prevents any risk of alloimmunization in the RHD negative recipient. The D negative phenotype is char...Background: The D antigen is the most important and immunogenic antigen of the Rh blood group;its correct screening prevents any risk of alloimmunization in the RHD negative recipient. The D negative phenotype is characterized by the absence of the D antigen (RH1) on the surface of the erythrocyte. Three main mechanisms can generate this absence: total or partial deletion of the RHD gene, insertion of base pairs within the said gene and gene conversion. The objective of this study was to report the first data on RHD genotyping in RHD negative congolese blood donors. Materials and Methods: Blood samples came from regular RHD-negative blood donors selected from the blood transfusion stations in Brazzaville and Pointe-Noire. They were analyzed individually by conventional PCR, targeting exons 4, 5, 7 and 10 of the RHD gene. Results: Fifty-nine regular RHD negative blood donors were selected for this study. The immuno-hematological profile was determined individually, and the dccee phenotype was the most frequent (n = 52;88.1%). The search for the weak D antigen was negative for all donors. Exons 4, 5, 7 and 10 of the RHD gene were amplified in the following respective proportions: 89.8%, 81.4%, 6.8% and 42.4%. Moreover, (1) donor was found to carry all four specific exons sought. Conclusion: Conventional PCR amplification allowed to study the presence of specific exons of the targeted D gene. At least one exon was detected in the entire study population. These results suggest that the RHD gene is indeed present in the donors studied and that the deletion cannot be considered as the main mechanism causing the RH-1 (D negative) phenotype in this sample.展开更多
To understand the genetic diversity and drug resistance status of Mycobocterium tuberculosis （M. tuberculosis） circulating in Xuzhou of China, the spacer-oligonucleotide typing （Spoligotyping） and multi-loci VNTRs...To understand the genetic diversity and drug resistance status of Mycobocterium tuberculosis （M. tuberculosis） circulating in Xuzhou of China, the spacer-oligonucleotide typing （Spoligotyping） and multi-loci VNTRs （variable number tandem repeats） analysis （MLVA） were utilized for the genotyping of the isolates. Drug susceptibility test （DST） was performed by the proportion method on the Lowenstein-Jensen （L-J） medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-1oci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.展开更多
Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locati...Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locations and sources were used in sequence and phylogenetic analysis. Results The full-length genome of genotypes V JEV, XZ0934, and Muar strain were composed of 10 983 and 10 988 nucleotides respectively and shared a lower level of identity with JEV genotypes I-IV, ranging from 78.4% （G I, KV1899） to 79.7% （G III, JaGAr01）, for the nucleotide sequences, and from 90.0%（G I, KV1899） to 91.8%（G III, JaGAr01） for the amino acid sequences. The open reading frame （ORF） of JEV genotype V spanned nucleotides 96 to 10 397 and encoded 3 433 amino acids. Interestingly, a comparison with JEV genotype I-IV revealed that 3 nucleotides （encoded with a serine residue） were inserted in the NS4A gene of JEV genotype V, and the insertion of nucleotides was also found in downstream of the ORF stop codon in 3’-untranslated region. Moreover, numerous amino acid mutations were observed in 3 functional domains of the E gene of JEV genotype V. Conclusion The molecular characterization of JEV genotype V is significantly different from that of the known genotypes I-IV. The mutations located in the coding region and the non-coding region may be molecular markers of JEV genotype V and warrant further studies to determine their effects on biology and immunogenicity of genotype V strains.展开更多
Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide： H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in...Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide： H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3＇ end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation （S31N）, a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.展开更多
We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution foll...We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus展开更多
Background: To preserve its nutritional properties, fish must have good sanitary quality. The objective of this study was to investigate some pathogens contaminating smoked, dried, and braised fish marketed in Ouagado...Background: To preserve its nutritional properties, fish must have good sanitary quality. The objective of this study was to investigate some pathogens contaminating smoked, dried, and braised fish marketed in Ouagadougou. Methodology: Potential pathogens of Enterobacteriaceae and Staphylococcus were screened in eight (8) species of processed fish. The investigation of the germs was carried out following the normative methods of microbiology. The identities of the strains were determined by API 20 E (BioMerieux S.A., France) and API STAPH (BioMerieux S.A., France) kits for Enterobacteriaceae and Staphylococcus species respectively. The uidA gene profile in Escherichia coli isolates was determined by simplex PCR. The identity of Staphylococcus aureus was confirmed by amplification of specific 23S rDNA regions and nuc gene profile with PCR. Results: A total of 235 fish samples were analyzed. A diversity of Enterobacteriaceae and Staphylococcus was detected. Twenty species of Enterobacteriaceae were identified among which, the most frequent were Escherichia coli, Salmonella sp, Raoultella ornithinolytica and Serratia odorifera, respectively in 22.6%, 4.3%, 28.9%, 17.4% of the samples analyzed. However, eleven species of Staphylococcus were identified among which, Staphylococcus xylosus, Staphylococcus aureus, Staphylococcus lugdunensis, and Staphylococcus sciuri were the most frequent with respective percentages of 47.7%, 23.4%, 12.8% and 10.6% of samples. For all the samples, the species frequently isolated were: Raoultella ornithinolytica, Escherichia coli, Serratia odorifera, Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus lugdunensis. The uidA gene specific to Escherichia coli was detected in 82.85% of strains (29/35). Amplification of the specific 23S rDNA region using staur primers was observed in 98% (49/50) of the isolated Staphylococcus aureus strains and the nuc gene was detected in 86% of Staphylococcus aureus strains. Conclusion: The isolated bacteria are potential pathogens involved in foodborne illnesses and intoxications. Effective sanitary safety systems must be implemented to guarantee the sanitary quality of fish supplied to consumers.展开更多
<i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> is an emerging ubiquitous and opportunistic pathogen that cur...<i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> is an emerging ubiquitous and opportunistic pathogen that currently contaminates a wide spectrum of foods including powdered milk and poses a lethal threat to neonates, the elderly and persons with immune deficiencies. They cause life threatening neonatal meningitis, septicemia, and necrotizing enterocolitis. A total of 360 samples of powdered infant formula were collected from postnatal hospital attendees reconstituting the PIF for their children in the North Central region of Nigeria where cases of infant mortality </span><span style="font-family:Verdana;">are </span><span style="font-family:""><span style="font-family:Verdana;">very high and presenting as enterocolitis and diarrhea. Pre-enriched samples were cultured in chromogenic </span><i><span style="font-family:Verdana;">Cronobacter</span></i><span style="font-family:Verdana;"> broth and were then further sub-cultured into a chromogenic </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> agar. They were positive, exhibiting yellowish cultures typical of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. Biochemical tests of the isolates were also carried out and indicated the presence of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The isolates were then characterized molecularly using specie specific PCR detection of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The targeted genes of interest were </span><i><span style="font-family:Verdana;">ompA</span></i><span style="font-family:Verdana;"> gene and </span><i><span style="font-family:Verdana;">CPA</span></i><span style="font-family:Verdana;"> gene. The isolates tested showed bands for </span><i><span style="font-family:Verdana;">ompA</span></i><span style="font-family:Verdana;"> gene on electrophoresis imager and were confirmed as </span><i><span style="font-family:Verdana;">Cronobacter sakazakii.</span></i><span style="font-family:Verdana;"> In Nigeria, majority of infants are still fed with PIF. There is no existing data on the detection of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> previously reported in the North central region of Nigeria hence the need to carry out the present study. The result of the study demonstrated the need for effective prevention and control measures as contamination of PIF with </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> constituted potential public health risk to neonates and infants.展开更多
A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by posi...A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by positive-and negative-ion electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results of negative-ion ESI FT-ICR MS showed that the N1 class species was the most abundant and the multifunctional group compounds,such as N1 O1,N1 O2,N1 S1,N1 S2,and N2 class species became abundant as the SFEF fraction became heavier.In positive-ion ESI mode,the relative abundance of N1 class species decreased gradually in the heavy SFEF fractions while that of multifunctional group compounds increased.The relative abundance of N4 V1 O1 increased dramatically in heavy fractions and the end-cut.The distributions of polar heteroatom species of VR derived from oilsands bitumen were similar with those of VR derived from the Venezuela Orinoco extra heavy oil.展开更多
Wild relatives possess potential genetic diversity for maize (<i><span style="font-family:Verdana;">Zea mays</span></i><span style="font-family:Verdana;"> L.) improvem...Wild relatives possess potential genetic diversity for maize (<i><span style="font-family:Verdana;">Zea mays</span></i><span style="font-family:Verdana;"> L.) improvement. Characterization of maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> introgression lines (ILs) is of great value to diversify the genetic base and improve the maize germplasm. Four maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> IL generations, </span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"> BC1, BC2, BC3, and RIL, were constructed under the elite inbred background of 48-2, elite inbred line that is widely used in maize breeding in Southwestern China, and were phenotyped in different years and genotyped with 56110 SNPs. The results indicated that 48-2 had higher phenotypic performances than all the characterized ILs on most of the agronomic traits. Compared with other ILs, BC2 individuals exhibited more similar performance to 48-2 on most traits and possessed the highest kernel ratio (66.5%). Population structure and principal component analysis indicated that BC3 individuals gathered closer to 48-2 and exhibited the lowest </span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;">-introgression frequency (0.50%), while BC2 (29.06%) and RIL (18.52%) showed higher introgression frequency. The high level of genetic diversity observed in the maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> ILs demonstrated that </span><i><span style="font-family:Verdana;">Z</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">mays</span></i><span style="font-family:Verdana;"> ssp. </span><i><span style="font-family:Verdana;">mexicana </span></i><span style="font-family:Verdana;">can serve as a potential source for the enrichment of maize germplasm.</span>展开更多
To the Editor:Fibroblast growth factor receptor(FGFR)fusion,although uncommon,represents an important target for cancer treatment,particularly for solid malignancies primarily treated with chemotherapy.Biliary tract c...To the Editor:Fibroblast growth factor receptor(FGFR)fusion,although uncommon,represents an important target for cancer treatment,particularly for solid malignancies primarily treated with chemotherapy.Biliary tract cancer(BTC)is a notable example.Although folinic acid,fluorouracil,and oxaliplatin(FOLFOX)was the standard second-line treatment for advanced BTC,the objective response rate(ORR)was only 5%.The advent of targeted therapies,such as pemigatinib,revolutionized the clinical response in this patient population.展开更多
In June 2013,the fi rst human H6N1 infl uenza virus infec-tion was confirmed in Taiwan.However,the origin and molecular characterization of this virus,A/Taiwan/2/2013(H6N1),have not been well studied thus far.In the p...In June 2013,the fi rst human H6N1 infl uenza virus infec-tion was confirmed in Taiwan.However,the origin and molecular characterization of this virus,A/Taiwan/2/2013(H6N1),have not been well studied thus far.In the present report,we performed phylogenetic and coalescent analy-ses of this virus and compared its molecular profi le/char-acteristics with other closely related strains.Molecular characterization of H6N1 revealed that it is a typical avian infl uenza virus of low pathogenicity,which might not rep-licate and propagate well in the upper airway in mammals.Phylogenetic analysis revealed that the virus clusters with A/chicken/Taiwan/A2837/2013(H6N1)in seven genes,except PB1.For the PB1 gene,A/Taiwan/2/2013 was clus-tered with a different H6N1 lineage from A/chicken/Taiwan/A2837/2013.Although a previous study demonstrated that the PB2,PA,and M genes of A/Taiwan/2/2013 might be derived from the H5N2 viruses,coalescent analyses revealed that these H5N2 viruses were derived from more recent strains than that of the ancestor of A/Taiwan/2/2013.Therefore,we propose that A/Taiwan/2/2013 is a reassor-tant from different H6N1 lineages circulating in chickens in Taiwan.Furthermore,compared to avian isolates,a sin-gle P186L(H3 numbering)substitution in the hemaggluti-nin H6 of the human isolate might increase the mammali-an receptor binding and,hence,this strain’s pathogenicity in humans.Overall,human infection with this virus seems an accidental event and is unlikely to cause an infl uenza pandemic.However,its co-circulation and potential reas-sortment with other infl uenza subtypes are still worthy of attention.展开更多
Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the bro...Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the brown planthopper, and were given the designations of Nlcryl and Nlcry2, with the accession numbers KM108578 and KM108579 in GenBank. The complementary DNA sequences ofNlcryl andNlcry2 are 1935 bp and 2463 bp in length, and they contain an open reading frame of 1629 bp and 1872 bp, encoding amino acids of 542 and 623, with a predicted molecular weight of 62.53 kDa and 70.60 kDa, respectively. Well-conserved motifs such as DNA-photolyase and FAD-binding-7 domains were observed in Nlcry1 and Nlcry2. Phylogenetic analysis demonstrated the proteins of Nlcry1 and Nlcry2 to be clustered into the insect＇s cryptochrome 1 and cryptochrome 2, respectively. Quantitative polymerase chain reaction showed that the daily oscillations of messenger RNA （mRNA） expression in the head of the brown planthopper were mild for Nlcryl, and modest for Nlcry2. Throughout all developmental stages, Nlcryl and Nlcry2 exhibited extreme fluctuations and distinctive expression profiles. Cryptochrome mRNA expression peaked immediately after adult emergence and then decreased subsequently. The tissue expression profiles of newly emerged brown planthopper adults showed higher expression levels of CRYs in the head than in the thorax or abdomen, as well as significantly higher levels of CRYs in the heads of the macropterous strain than in the heads of the brachypterous strain. Taken together, the results of our study suggest that the two cryptochrome genes characterized in the brown planthopper might be associated with developmental physiology and migration.展开更多
The current study was performed to evaluate the liver function status as well as molecular characterization of the recovered worms in rats experimentally infected with F. hepatica. Sixteen male Wister rats aged 30 day...The current study was performed to evaluate the liver function status as well as molecular characterization of the recovered worms in rats experimentally infected with F. hepatica. Sixteen male Wister rats aged 30 days were randomly allocated into two groups (n = 8). The first group was infected orally with 15 viable encysted metacercaria of F. hepatica per animal. The other group was kept non-infected (control group). At zero time (before infection), the 2<sup>nd</sup>, 4<sup>th</sup>, 6<sup>th</sup>, 8<sup>th</sup>, 10<sup>th</sup>, 12<sup>th</sup> and 14<sup>th</sup> weeks post-infection (WPI), blood and serum samples were collected via puncture of retro-orbital plexus of veins from each rat. Serum enzyme level (AST and ALT) and total protein were measured, and the serum protein profile was carried out using agarose gel electrophoresis. During the period of the experiment, serum ALT and AST activities and serum total globulins significantly increased while serum total proteins and albumin markedly decreased in the infected group. On the 14<sup>th</sup> WPI, the data of the electropherogram showed that globulin fractions (α1-, β- and γ-globulin) levels were significantly increased while α2-globulin was markedly decreased in the infected group. The molecular analysis confirmed the amplification of the ITS1, ITS2 and NDI genes of F. hepatica recovered from the infected liver of rats with amplicon sizes of 630, 510 and 560 bp, respectively. Sequencing of the amplified ITS gene resulted in the determination of 3 strains (PP108836, PP108837, and PP108838). Also, analysis of the ITS2 gene resulted in obtaining 3 isolates under the accession numbers (PP109065, PP109066, and PP109067). In conclusion, fasciolosis in the rat model is suitable for routine experimental infections and caused a pronounced liver dysfunction with discharging of the Fasciola eggs in the faeces and the development of adult stages in the bile ducts. Furthermore, molecular techniques are a sensitive tool for the identification and characterisation of the Fasciola parasite.展开更多
Phenylalanine ammonia-lyase(PAL),which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid,is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropa...Phenylalanine ammonia-lyase(PAL),which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid,is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropanoid biosynthetic pathway of plants and microbes.Schisandra chinensis,a woody vine plant belonging to the family of Magnoliaceae,is a rich source of dibenzocyclooctadiene lignans exhibiting potent activity.However,the functional role of PAL in the biosynthesis of lignan is relatively limited,compared with those in lignin and flavonoids biosynthesis.Therefore,it is essential to clone and characterize the PAL genes from this valuable medicinal plant.In this study,molecular cloning and characterization of three PAL genes(ScPAL1−3)from S.chinensis was carried out.ScPALs were cloned using RACE PCR.The sequence analysis of the three ScPALs was carried out to give basic characteristics followed by docking analysis.In order to determine their catalytic activity,recombinant protein was obtained by heterologous expression in pCold-TF vector in Escherichia coli(BL21-DE3),followed by Ni-affinity purification.The catalytic product of the purified recombinant proteins was verified using RP-HPLC through comparing with standard compounds.The optimal temperature,pH value and effects of different metal ions were determined.Vmax,Kcat and Km values were determined under the optimal conditions.The expression of three ScPALs in different tissues was also determined.Our work provided essential information for the function of ScPALs.展开更多
Plant leaves play a significant role in photosynthesis. Normal chloroplast development is critical for plant growth and yield performance. Defect of the chlorophyll in chloroplasts may cause abnormal leaf colors, such...Plant leaves play a significant role in photosynthesis. Normal chloroplast development is critical for plant growth and yield performance. Defect of the chlorophyll in chloroplasts may cause abnormal leaf colors, such as yellow, white, or stripe. Chloroplasts have their own genomes encoding for about 100 genes that are essential for plastid protein synthesis and photosynthesis （Kanno and Hirai, 1993; Sato et al., 1999）. Moreover, over 3000 proteins encoded by plant nuclear genomes target to the chloroplasts and participate in the chloroplast development and/or photosynthesis. Hitherto, a number of plant genes, which encode for enzymes involved in chlorophyll biosynthetic pathways,展开更多
Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica...Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica, salamae, arizonae,展开更多
Cotton is viewed as the most important cash crop in the world,and sustains the agricultural economies of many nations by providing a sustainable fiber product for the textile industry.Due to
Sea Island cotton(Gossypium barbadense L.) has been highly valued in Verticillium wilt resistance and many fiber qualities including fiber length,strength,and fineness.To identify whether
Verticillium dahliae Kleb.is a necrotrophic plant pathogen which causes serious soil borne vascular disease in cotton.The molecular basis the defense response of cotton to this pathogen is
文摘Background: The D antigen is the most important and immunogenic antigen of the Rh blood group;its correct screening prevents any risk of alloimmunization in the RHD negative recipient. The D negative phenotype is characterized by the absence of the D antigen (RH1) on the surface of the erythrocyte. Three main mechanisms can generate this absence: total or partial deletion of the RHD gene, insertion of base pairs within the said gene and gene conversion. The objective of this study was to report the first data on RHD genotyping in RHD negative congolese blood donors. Materials and Methods: Blood samples came from regular RHD-negative blood donors selected from the blood transfusion stations in Brazzaville and Pointe-Noire. They were analyzed individually by conventional PCR, targeting exons 4, 5, 7 and 10 of the RHD gene. Results: Fifty-nine regular RHD negative blood donors were selected for this study. The immuno-hematological profile was determined individually, and the dccee phenotype was the most frequent (n = 52;88.1%). The search for the weak D antigen was negative for all donors. Exons 4, 5, 7 and 10 of the RHD gene were amplified in the following respective proportions: 89.8%, 81.4%, 6.8% and 42.4%. Moreover, (1) donor was found to carry all four specific exons sought. Conclusion: Conventional PCR amplification allowed to study the presence of specific exons of the targeted D gene. At least one exon was detected in the entire study population. These results suggest that the RHD gene is indeed present in the donors studied and that the deletion cannot be considered as the main mechanism causing the RH-1 (D negative) phenotype in this sample.
基金funded by the projects 2013ZX10003002-001 of Chinese National Key Program of Mega Infectious Disease of the National 12th Five-Year Planthe Science and Technology Innovation Team Support project CX201412 of Changzhi Medical College
文摘To understand the genetic diversity and drug resistance status of Mycobocterium tuberculosis （M. tuberculosis） circulating in Xuzhou of China, the spacer-oligonucleotide typing （Spoligotyping） and multi-loci VNTRs （variable number tandem repeats） analysis （MLVA） were utilized for the genotyping of the isolates. Drug susceptibility test （DST） was performed by the proportion method on the Lowenstein-Jensen （L-J） medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-1oci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.
基金supported by grants from the Ministry of Science and Technology,China(2011CB504702)National Natural Science Foundation of China(81290342)Development Grant of State Key Laboratory for Infectious Disease Prevention and Control(2008SKLID105)
文摘Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locations and sources were used in sequence and phylogenetic analysis. Results The full-length genome of genotypes V JEV, XZ0934, and Muar strain were composed of 10 983 and 10 988 nucleotides respectively and shared a lower level of identity with JEV genotypes I-IV, ranging from 78.4% （G I, KV1899） to 79.7% （G III, JaGAr01）, for the nucleotide sequences, and from 90.0%（G I, KV1899） to 91.8%（G III, JaGAr01） for the amino acid sequences. The open reading frame （ORF） of JEV genotype V spanned nucleotides 96 to 10 397 and encoded 3 433 amino acids. Interestingly, a comparison with JEV genotype I-IV revealed that 3 nucleotides （encoded with a serine residue） were inserted in the NS4A gene of JEV genotype V, and the insertion of nucleotides was also found in downstream of the ORF stop codon in 3’-untranslated region. Moreover, numerous amino acid mutations were observed in 3 functional domains of the E gene of JEV genotype V. Conclusion The molecular characterization of JEV genotype V is significantly different from that of the known genotypes I-IV. The mutations located in the coding region and the non-coding region may be molecular markers of JEV genotype V and warrant further studies to determine their effects on biology and immunogenicity of genotype V strains.
基金Supported by the Natural Science Foundation of Jiangsu Province(BK2009434)the Innovation Platform for Public Health Emergency Preparedness and Response(NO.ZX201109)the Key Medical Talent Foundation of Jiangsu Province(RC2011084)
文摘Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide： H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3＇ end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation （S31N）, a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.
文摘We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus
文摘Background: To preserve its nutritional properties, fish must have good sanitary quality. The objective of this study was to investigate some pathogens contaminating smoked, dried, and braised fish marketed in Ouagadougou. Methodology: Potential pathogens of Enterobacteriaceae and Staphylococcus were screened in eight (8) species of processed fish. The investigation of the germs was carried out following the normative methods of microbiology. The identities of the strains were determined by API 20 E (BioMerieux S.A., France) and API STAPH (BioMerieux S.A., France) kits for Enterobacteriaceae and Staphylococcus species respectively. The uidA gene profile in Escherichia coli isolates was determined by simplex PCR. The identity of Staphylococcus aureus was confirmed by amplification of specific 23S rDNA regions and nuc gene profile with PCR. Results: A total of 235 fish samples were analyzed. A diversity of Enterobacteriaceae and Staphylococcus was detected. Twenty species of Enterobacteriaceae were identified among which, the most frequent were Escherichia coli, Salmonella sp, Raoultella ornithinolytica and Serratia odorifera, respectively in 22.6%, 4.3%, 28.9%, 17.4% of the samples analyzed. However, eleven species of Staphylococcus were identified among which, Staphylococcus xylosus, Staphylococcus aureus, Staphylococcus lugdunensis, and Staphylococcus sciuri were the most frequent with respective percentages of 47.7%, 23.4%, 12.8% and 10.6% of samples. For all the samples, the species frequently isolated were: Raoultella ornithinolytica, Escherichia coli, Serratia odorifera, Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus lugdunensis. The uidA gene specific to Escherichia coli was detected in 82.85% of strains (29/35). Amplification of the specific 23S rDNA region using staur primers was observed in 98% (49/50) of the isolated Staphylococcus aureus strains and the nuc gene was detected in 86% of Staphylococcus aureus strains. Conclusion: The isolated bacteria are potential pathogens involved in foodborne illnesses and intoxications. Effective sanitary safety systems must be implemented to guarantee the sanitary quality of fish supplied to consumers.
文摘<i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> is an emerging ubiquitous and opportunistic pathogen that currently contaminates a wide spectrum of foods including powdered milk and poses a lethal threat to neonates, the elderly and persons with immune deficiencies. They cause life threatening neonatal meningitis, septicemia, and necrotizing enterocolitis. A total of 360 samples of powdered infant formula were collected from postnatal hospital attendees reconstituting the PIF for their children in the North Central region of Nigeria where cases of infant mortality </span><span style="font-family:Verdana;">are </span><span style="font-family:""><span style="font-family:Verdana;">very high and presenting as enterocolitis and diarrhea. Pre-enriched samples were cultured in chromogenic </span><i><span style="font-family:Verdana;">Cronobacter</span></i><span style="font-family:Verdana;"> broth and were then further sub-cultured into a chromogenic </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> agar. They were positive, exhibiting yellowish cultures typical of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. Biochemical tests of the isolates were also carried out and indicated the presence of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The isolates were then characterized molecularly using specie specific PCR detection of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;">. The targeted genes of interest were </span><i><span style="font-family:Verdana;">ompA</span></i><span style="font-family:Verdana;"> gene and </span><i><span style="font-family:Verdana;">CPA</span></i><span style="font-family:Verdana;"> gene. The isolates tested showed bands for </span><i><span style="font-family:Verdana;">ompA</span></i><span style="font-family:Verdana;"> gene on electrophoresis imager and were confirmed as </span><i><span style="font-family:Verdana;">Cronobacter sakazakii.</span></i><span style="font-family:Verdana;"> In Nigeria, majority of infants are still fed with PIF. There is no existing data on the detection of </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> previously reported in the North central region of Nigeria hence the need to carry out the present study. The result of the study demonstrated the need for effective prevention and control measures as contamination of PIF with </span><i><span style="font-family:Verdana;">Cronobacter sakazakii</span></i><span style="font-family:Verdana;"> constituted potential public health risk to neonates and infants.
文摘A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by positive-and negative-ion electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results of negative-ion ESI FT-ICR MS showed that the N1 class species was the most abundant and the multifunctional group compounds,such as N1 O1,N1 O2,N1 S1,N1 S2,and N2 class species became abundant as the SFEF fraction became heavier.In positive-ion ESI mode,the relative abundance of N1 class species decreased gradually in the heavy SFEF fractions while that of multifunctional group compounds increased.The relative abundance of N4 V1 O1 increased dramatically in heavy fractions and the end-cut.The distributions of polar heteroatom species of VR derived from oilsands bitumen were similar with those of VR derived from the Venezuela Orinoco extra heavy oil.
文摘Wild relatives possess potential genetic diversity for maize (<i><span style="font-family:Verdana;">Zea mays</span></i><span style="font-family:Verdana;"> L.) improvement. Characterization of maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> introgression lines (ILs) is of great value to diversify the genetic base and improve the maize germplasm. Four maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> IL generations, </span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;"> BC1, BC2, BC3, and RIL, were constructed under the elite inbred background of 48-2, elite inbred line that is widely used in maize breeding in Southwestern China, and were phenotyped in different years and genotyped with 56110 SNPs. The results indicated that 48-2 had higher phenotypic performances than all the characterized ILs on most of the agronomic traits. Compared with other ILs, BC2 individuals exhibited more similar performance to 48-2 on most traits and possessed the highest kernel ratio (66.5%). Population structure and principal component analysis indicated that BC3 individuals gathered closer to 48-2 and exhibited the lowest </span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;">-introgression frequency (0.50%), while BC2 (29.06%) and RIL (18.52%) showed higher introgression frequency. The high level of genetic diversity observed in the maize-</span><i><span style="font-family:Verdana;">mexicana</span></i><span style="font-family:Verdana;"> ILs demonstrated that </span><i><span style="font-family:Verdana;">Z</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">mays</span></i><span style="font-family:Verdana;"> ssp. </span><i><span style="font-family:Verdana;">mexicana </span></i><span style="font-family:Verdana;">can serve as a potential source for the enrichment of maize germplasm.</span>
基金The study was supported by grants from Jiangsu Province 333 High Level Talents Project,Beijing Xisike Clinical Oncology Research Foundation(No.Y-HR2019-0367)Beijing Science and Technology Innovation Medical Development Foundation(No.KC2021-JX-0186-124).
文摘To the Editor:Fibroblast growth factor receptor(FGFR)fusion,although uncommon,represents an important target for cancer treatment,particularly for solid malignancies primarily treated with chemotherapy.Biliary tract cancer(BTC)is a notable example.Although folinic acid,fluorouracil,and oxaliplatin(FOLFOX)was the standard second-line treatment for advanced BTC,the objective response rate(ORR)was only 5%.The advent of targeted therapies,such as pemigatinib,revolutionized the clinical response in this patient population.
基金the National Basic Research Pro-gram(973 Program)(Nos.2010CB530303,2011CB504703,and 2012CB955501an intramural special grant for influenza virus research from the Chinese Academy of Sciences(KSZD-EW-Z-002)the Doctoral Starting up Foundation of Taishan Medical College.GFG is a leading principal investigator of the Innova-tive Research Group of the National Natural Science Foundation of China(Grant No.81021003)。
文摘In June 2013,the fi rst human H6N1 infl uenza virus infec-tion was confirmed in Taiwan.However,the origin and molecular characterization of this virus,A/Taiwan/2/2013(H6N1),have not been well studied thus far.In the present report,we performed phylogenetic and coalescent analy-ses of this virus and compared its molecular profi le/char-acteristics with other closely related strains.Molecular characterization of H6N1 revealed that it is a typical avian infl uenza virus of low pathogenicity,which might not rep-licate and propagate well in the upper airway in mammals.Phylogenetic analysis revealed that the virus clusters with A/chicken/Taiwan/A2837/2013(H6N1)in seven genes,except PB1.For the PB1 gene,A/Taiwan/2/2013 was clus-tered with a different H6N1 lineage from A/chicken/Taiwan/A2837/2013.Although a previous study demonstrated that the PB2,PA,and M genes of A/Taiwan/2/2013 might be derived from the H5N2 viruses,coalescent analyses revealed that these H5N2 viruses were derived from more recent strains than that of the ancestor of A/Taiwan/2/2013.Therefore,we propose that A/Taiwan/2/2013 is a reassor-tant from different H6N1 lineages circulating in chickens in Taiwan.Furthermore,compared to avian isolates,a sin-gle P186L(H3 numbering)substitution in the hemaggluti-nin H6 of the human isolate might increase the mammali-an receptor binding and,hence,this strain’s pathogenicity in humans.Overall,human infection with this virus seems an accidental event and is unlikely to cause an infl uenza pandemic.However,its co-circulation and potential reas-sortment with other infl uenza subtypes are still worthy of attention.
基金We thank the staff in the Beijing READ BIO Bioinformatic Technology Company for their assistance in the phylogenetic inference and bioinformatic analysis of brown planthopper CRY proteins. This research was supported by the Key Program of National Natural Science of China （51037006）, the National Basic Research Program of China ＂973＂ （2010CB126200） and the National Nature Science Foundations of China （31170362, 31272051, 31470454 and 31070755）.
文摘Cryptochromes （CRYs） are blue and UV light photoreceptors, known to play key roles in circadian rhythms and in the light-dependent magnetosensitivity of insects. Two novel cryptochrome genes were cloned from the brown planthopper, and were given the designations of Nlcryl and Nlcry2, with the accession numbers KM108578 and KM108579 in GenBank. The complementary DNA sequences ofNlcryl andNlcry2 are 1935 bp and 2463 bp in length, and they contain an open reading frame of 1629 bp and 1872 bp, encoding amino acids of 542 and 623, with a predicted molecular weight of 62.53 kDa and 70.60 kDa, respectively. Well-conserved motifs such as DNA-photolyase and FAD-binding-7 domains were observed in Nlcry1 and Nlcry2. Phylogenetic analysis demonstrated the proteins of Nlcry1 and Nlcry2 to be clustered into the insect＇s cryptochrome 1 and cryptochrome 2, respectively. Quantitative polymerase chain reaction showed that the daily oscillations of messenger RNA （mRNA） expression in the head of the brown planthopper were mild for Nlcryl, and modest for Nlcry2. Throughout all developmental stages, Nlcryl and Nlcry2 exhibited extreme fluctuations and distinctive expression profiles. Cryptochrome mRNA expression peaked immediately after adult emergence and then decreased subsequently. The tissue expression profiles of newly emerged brown planthopper adults showed higher expression levels of CRYs in the head than in the thorax or abdomen, as well as significantly higher levels of CRYs in the heads of the macropterous strain than in the heads of the brachypterous strain. Taken together, the results of our study suggest that the two cryptochrome genes characterized in the brown planthopper might be associated with developmental physiology and migration.
文摘The current study was performed to evaluate the liver function status as well as molecular characterization of the recovered worms in rats experimentally infected with F. hepatica. Sixteen male Wister rats aged 30 days were randomly allocated into two groups (n = 8). The first group was infected orally with 15 viable encysted metacercaria of F. hepatica per animal. The other group was kept non-infected (control group). At zero time (before infection), the 2<sup>nd</sup>, 4<sup>th</sup>, 6<sup>th</sup>, 8<sup>th</sup>, 10<sup>th</sup>, 12<sup>th</sup> and 14<sup>th</sup> weeks post-infection (WPI), blood and serum samples were collected via puncture of retro-orbital plexus of veins from each rat. Serum enzyme level (AST and ALT) and total protein were measured, and the serum protein profile was carried out using agarose gel electrophoresis. During the period of the experiment, serum ALT and AST activities and serum total globulins significantly increased while serum total proteins and albumin markedly decreased in the infected group. On the 14<sup>th</sup> WPI, the data of the electropherogram showed that globulin fractions (α1-, β- and γ-globulin) levels were significantly increased while α2-globulin was markedly decreased in the infected group. The molecular analysis confirmed the amplification of the ITS1, ITS2 and NDI genes of F. hepatica recovered from the infected liver of rats with amplicon sizes of 630, 510 and 560 bp, respectively. Sequencing of the amplified ITS gene resulted in the determination of 3 strains (PP108836, PP108837, and PP108838). Also, analysis of the ITS2 gene resulted in obtaining 3 isolates under the accession numbers (PP109065, PP109066, and PP109067). In conclusion, fasciolosis in the rat model is suitable for routine experimental infections and caused a pronounced liver dysfunction with discharging of the Fasciola eggs in the faeces and the development of adult stages in the bile ducts. Furthermore, molecular techniques are a sensitive tool for the identification and characterisation of the Fasciola parasite.
基金supported by the National Key R&D Program of China(No.2017YFC1701200).
文摘Phenylalanine ammonia-lyase(PAL),which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid,is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropanoid biosynthetic pathway of plants and microbes.Schisandra chinensis,a woody vine plant belonging to the family of Magnoliaceae,is a rich source of dibenzocyclooctadiene lignans exhibiting potent activity.However,the functional role of PAL in the biosynthesis of lignan is relatively limited,compared with those in lignin and flavonoids biosynthesis.Therefore,it is essential to clone and characterize the PAL genes from this valuable medicinal plant.In this study,molecular cloning and characterization of three PAL genes(ScPAL1−3)from S.chinensis was carried out.ScPALs were cloned using RACE PCR.The sequence analysis of the three ScPALs was carried out to give basic characteristics followed by docking analysis.In order to determine their catalytic activity,recombinant protein was obtained by heterologous expression in pCold-TF vector in Escherichia coli(BL21-DE3),followed by Ni-affinity purification.The catalytic product of the purified recombinant proteins was verified using RP-HPLC through comparing with standard compounds.The optimal temperature,pH value and effects of different metal ions were determined.Vmax,Kcat and Km values were determined under the optimal conditions.The expression of three ScPALs in different tissues was also determined.Our work provided essential information for the function of ScPALs.
基金supported by a grant from Ministry of Science and Technology of China (No. 2012AA10A303)
文摘Plant leaves play a significant role in photosynthesis. Normal chloroplast development is critical for plant growth and yield performance. Defect of the chlorophyll in chloroplasts may cause abnormal leaf colors, such as yellow, white, or stripe. Chloroplasts have their own genomes encoding for about 100 genes that are essential for plastid protein synthesis and photosynthesis （Kanno and Hirai, 1993; Sato et al., 1999）. Moreover, over 3000 proteins encoded by plant nuclear genomes target to the chloroplasts and participate in the chloroplast development and/or photosynthesis. Hitherto, a number of plant genes, which encode for enzymes involved in chlorophyll biosynthetic pathways,
基金financially supported by the University of Malaya Research Grant (UMRG) (RP003A-13BIO)UM Postgraduate Research Fund (PPP) (PS319/2010B)
文摘Salmonella is a member of the family Enterobacteriaceae. This genus comprises two species, namely Salmonella enterica and Salmonella bongori. Salmonella enterica is further divided into six subspecies, namely enterica, salamae, arizonae,
文摘Cotton is viewed as the most important cash crop in the world,and sustains the agricultural economies of many nations by providing a sustainable fiber product for the textile industry.Due to
文摘Sea Island cotton(Gossypium barbadense L.) has been highly valued in Verticillium wilt resistance and many fiber qualities including fiber length,strength,and fineness.To identify whether
文摘Verticillium dahliae Kleb.is a necrotrophic plant pathogen which causes serious soil borne vascular disease in cotton.The molecular basis the defense response of cotton to this pathogen is
