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
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
One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no ...One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no study has been done on Beninese Xoo strains. We do not know whether the pathogen has already passed into the rice varieties grown, or if they are exposed to other bacteria. Whereas the use of resistant varieties, carrying resistance genes, is the only highly effective and environmentally friendly way to control this disease, no information is available on these Xoo resistance genes in rice varieties grown in Benin apart from the one we recently. This study aims to identify Beninese Xoo strains, causing BLB and screen rice varieties grown in Benin for the main resistance genes. Diseased rice leaves showing typical symptoms of fire blight collected from different rice fields in the three phytogeographic areas of Benin were analyzed by PCR for Xoo-specific sequence identification. Furthermore, seventy-five collected rice accessions were screened to identify xa5, Xa7, xa13, and Xa21 resistance genes to Xoo. The results reveal that Xanthomonas oryzae was identified in two fields in Banikouara and one in Malanville. On the other hand, Sphingomonas sp. has been identified in several other rice fields in Benin. Forty-seven of seventy-five rice accessions examined (62.66%) carried Xoo resistance genes with 3 (4%) and 40 (53.33%) of xa5 and Xa21 respectively. None of the accessions had either Xa7 or xa13 resistance genes. Three accessions possess both xa5 and Xa21 genes. Isogenic lines IRBB60 and IRBB21, supposed to be a positive control, presented a Xoo sensitivity allele. These results indicate that Xoo has moved from the wild rice variety to the cultivated variety in northern Benin and varietal improvement programs must be implemented with varieties having several resistance genes for the efficient response against a possible BLB pandemic in Benin.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
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
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
<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
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
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
Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing infections resulting in severe morbidity and mortality worldwide. To date, the true nature and extent of MRSA infections in the Caribbean ...Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing infections resulting in severe morbidity and mortality worldwide. To date, the true nature and extent of MRSA infections in the Caribbean are not well understood. This is a review of the limited studies in the Caribbean describing the prevalence, epidemiology, and molecular characteristics of MRSA in hospitalized and non-hospitalized patients. Relevant articles were searched and extracted from PubMed and Mendeley and a narrative review of the findings was constructed. An aggregate of 24 articles, from 1999 to 2020, was found from 10 of 27 countries. Majority of the studies were from Trinidad and Tobago (29%) and Jamaica (21%) while 50% were from Barbados, Dominican Republic, Martinique, Haiti, Cuba, St. Kits & Nevis, Guadeloupe, and Guyana. Approximately 75% of investigations were conducted on hospitalized patients versus 20% on outpatients. The data revealed geographical differences in the prevalence of MRSA within the Caribbean;20% - 100% of Staphylococcus aureus clinical isolates from hospitalized patients and outpatients were resistant to methicillin, macrolides, and fluoroquinolones, but susceptible to several non-beta lactam antibiotics, due to the widespread occurrence of CA-MRSA clone ST8 SCCmec IV, PVL positive. There was moderate prevalence of ST72 SCCmec V (14% - 25%) in both hospital and community settings in a few of the countries while ST30 SCCmec IV, PVL positive, was moderately prevalent (27%) only in Dominican Republic. Also, there was moderate prevalence of HA-MRSA ST5 SCCmec II (18%) in community settings in the Dominican Republic and Martinique, but high prevalence of HA-MRSA ST239 SCCmec III (60%) in hospitalized patients in Cuba and Trinidad & Tobago. The epidemiologic profile of MRSA in both hospital and community settings is changing in the Caribbean. Epidemiological studies on outpatient settings and the implementation of stringent hospital infection control measures are needed in the region.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
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
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
CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in c...CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in cotton.For the further research,we isolated two CAP homologues from wild展开更多
Pancreatic cancer,a highly fatal malignancy,is predicted to rank as the second leading cause of cancer-related death in the next decade.This highlights the urgent need for new insights into personalized diagnosis and ...Pancreatic cancer,a highly fatal malignancy,is predicted to rank as the second leading cause of cancer-related death in the next decade.This highlights the urgent need for new insights into personalized diagnosis and treatment.Although molecular subtypes of pancreatic cancer were well established in genomics and transcriptomics,few known molec-ular classifications are translated to guide clinical strategies and require a paradigm shift.Notably,chronically developing and continuously improving high-throughput technologies and systems serve as an important driving force to further portray the molecular landscape of pancreatic cancer in terms of epigenomics,proteomics,metabonomics,and metagenomics.Therefore,a more comprehensive understanding of molecular classifications at multiple levels using an integrated multi-omics approach holds great promise to exploit more potential ther-apeutic options.In this review,we recapitulated the molecular spectrum from different omics levels,discussed various subtypes on multi-omics means to move one step forward towards bench-to-beside translation of pancreatic cancer with clinical impact,and proposed some methodological andscientific challengesinstore.展开更多
AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical ...AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPI-YA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using χ2 test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.展开更多
Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and in...Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.展开更多
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.
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One of the most devastating diseases of rice worldwide is bacterial blight (BLB) caused by Xanthomonas oryzae pv. Oryzae (Xoo). In Benin, Xoo was first described in 2013 on wild rice Oryzae longistaminata. So far, no study has been done on Beninese Xoo strains. We do not know whether the pathogen has already passed into the rice varieties grown, or if they are exposed to other bacteria. Whereas the use of resistant varieties, carrying resistance genes, is the only highly effective and environmentally friendly way to control this disease, no information is available on these Xoo resistance genes in rice varieties grown in Benin apart from the one we recently. This study aims to identify Beninese Xoo strains, causing BLB and screen rice varieties grown in Benin for the main resistance genes. Diseased rice leaves showing typical symptoms of fire blight collected from different rice fields in the three phytogeographic areas of Benin were analyzed by PCR for Xoo-specific sequence identification. Furthermore, seventy-five collected rice accessions were screened to identify xa5, Xa7, xa13, and Xa21 resistance genes to Xoo. The results reveal that Xanthomonas oryzae was identified in two fields in Banikouara and one in Malanville. On the other hand, Sphingomonas sp. has been identified in several other rice fields in Benin. Forty-seven of seventy-five rice accessions examined (62.66%) carried Xoo resistance genes with 3 (4%) and 40 (53.33%) of xa5 and Xa21 respectively. None of the accessions had either Xa7 or xa13 resistance genes. Three accessions possess both xa5 and Xa21 genes. Isogenic lines IRBB60 and IRBB21, supposed to be a positive control, presented a Xoo sensitivity allele. These results indicate that Xoo has moved from the wild rice variety to the cultivated variety in northern Benin and varietal improvement programs must be implemented with varieties having several resistance genes for the efficient response against a possible BLB pandemic in Benin.
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 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<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.
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Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing infections resulting in severe morbidity and mortality worldwide. To date, the true nature and extent of MRSA infections in the Caribbean are not well understood. This is a review of the limited studies in the Caribbean describing the prevalence, epidemiology, and molecular characteristics of MRSA in hospitalized and non-hospitalized patients. Relevant articles were searched and extracted from PubMed and Mendeley and a narrative review of the findings was constructed. An aggregate of 24 articles, from 1999 to 2020, was found from 10 of 27 countries. Majority of the studies were from Trinidad and Tobago (29%) and Jamaica (21%) while 50% were from Barbados, Dominican Republic, Martinique, Haiti, Cuba, St. Kits & Nevis, Guadeloupe, and Guyana. Approximately 75% of investigations were conducted on hospitalized patients versus 20% on outpatients. The data revealed geographical differences in the prevalence of MRSA within the Caribbean;20% - 100% of Staphylococcus aureus clinical isolates from hospitalized patients and outpatients were resistant to methicillin, macrolides, and fluoroquinolones, but susceptible to several non-beta lactam antibiotics, due to the widespread occurrence of CA-MRSA clone ST8 SCCmec IV, PVL positive. There was moderate prevalence of ST72 SCCmec V (14% - 25%) in both hospital and community settings in a few of the countries while ST30 SCCmec IV, PVL positive, was moderately prevalent (27%) only in Dominican Republic. Also, there was moderate prevalence of HA-MRSA ST5 SCCmec II (18%) in community settings in the Dominican Republic and Martinique, but high prevalence of HA-MRSA ST239 SCCmec III (60%) in hospitalized patients in Cuba and Trinidad & Tobago. The epidemiologic profile of MRSA in both hospital and community settings is changing in the Caribbean. Epidemiological studies on outpatient settings and the implementation of stringent hospital infection control measures are needed in the region.
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>
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
文摘CAP,an adenylyl cyclase-associated protein,is predicted to be involved in cytoskeletal organization and signal transduction.Recently,we found that CAP may play an important role in fuzz-like fiber cell initiation in cotton.For the further research,we isolated two CAP homologues from wild
基金supported by the National Natural Science Foundation of China (No.81972321,82273455to L.Y.)CAMS Innovation Fund for Medical Sciences (CIFMS) (No.2021-I2M-1-002 to Y.Z.)+1 种基金the National High Level Hospital Clinical Research Funding (China) (No.2022-PUMCH-D-001)the National Multidisciplinary Cooperative Diagnosissand Treatment Capacity Building Project for Major Diseases (China).
文摘Pancreatic cancer,a highly fatal malignancy,is predicted to rank as the second leading cause of cancer-related death in the next decade.This highlights the urgent need for new insights into personalized diagnosis and treatment.Although molecular subtypes of pancreatic cancer were well established in genomics and transcriptomics,few known molec-ular classifications are translated to guide clinical strategies and require a paradigm shift.Notably,chronically developing and continuously improving high-throughput technologies and systems serve as an important driving force to further portray the molecular landscape of pancreatic cancer in terms of epigenomics,proteomics,metabonomics,and metagenomics.Therefore,a more comprehensive understanding of molecular classifications at multiple levels using an integrated multi-omics approach holds great promise to exploit more potential ther-apeutic options.In this review,we recapitulated the molecular spectrum from different omics levels,discussed various subtypes on multi-omics means to move one step forward towards bench-to-beside translation of pancreatic cancer with clinical impact,and proposed some methodological andscientific challengesinstore.
基金Supported by Sciences Faculty,Los Andes University,Bogotá,Colombia and National Cancer Institute,Bogotá,Colombia,Grant No.41030310-28 (to Bravo MM)
文摘AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPI-YA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using χ2 test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.
文摘Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.