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Objective@#To analyze the molecular typing characteristics by pulsed field gel electrophoresis (PFGE), drug resistance and virulence genes of Salmonella typhimurium in Longyan city in order to provide reference for the prevention and control.@*Methods@#A total of 79 Salmonella typhimurium strains were isolated from sporadic cases of diarrhea and food poisoning and raw poultry meat samples during 2010 to 2017. PFGE was performed to measure the minimum inhibitory concentrations (MIC) of 15 commonly used drugs against them. PCR was used to detect nine virulence genes (sopB, invA, sifA, sscA, sseE, spvB, pefA, spvR, spvC) in 55 strains.@*Results@#The 79 Salmonella typhimurium strains belonged to 61 PFGE types. There were 10, three and four strains of P1, P3 and P21 types, respectively. Seven P1 type strains were isolate from one food poisoning event. According to the 85% classification standard, 79 Salmonella typhimurium strains could be divided into five predominant gene clusters (G1-G5). Drug susceptibility test showed that the 79 strains had the highest resistance rate to ampicillin (88.61%), followed by that to tetracycline (87.34%) and streptomycin (73.41%). Multidrug resistant bacteria resistant to three or more antibacterial drugs accounted for 84.81% (67/79). All of the 55 strains carried invA, sopB, sseE and sscA genes. The other five genes, sifA, spvC, spvB, spvR and pefA, were detected in 54, 31. 10, 11 and 12 strains, respectively. There were 76.4% (42/55) of the strains carrying five or six virulence genes and all were positive for invA, sopB, sseE, sscA and sifA, and negative for spvB, spvR and pefA. The strains carrying all of the nine virulence genes accounted for 18.2% (10/55).@*Conclusions@#Salmonella typhimurium strains isolated in Longyan city had a diverse PFGE type. P1, P3 and P21 types were the three predominant PFGE types. In the food poisoning event, PFGE molecular typing could quickly alert the outbreak and traceability of Salmonella typhimurium. Attention should be paid to the multidrug resistance in Salmonella typhimurium. Monitoring of multidrug-resistant strains and supervision on antibacterial drug usage should be strengthened. Salmonella typhimurium had high virulence as it carried many virulence genes.
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Objective To analyze the pulse-field gel electrophoresis (PFGE) patterns and antibiotic resistance of Salmonella enteritidisstrains isolated in Longyan city in order to provide reference for effective control, clinical diagnosis and treatment of outbreaks of food-borne diseases.Methods Seventy-seven Salmonella enteritidis strains isolated from food poisoning cases, livestock and poultry meat samples collected for food safety risk monitoring and sporadic cases in 2014 and 2016 were analyzed by PFGE.Antibiotic susceptibility testing was carried out to determine the minimum inhibitory concentrations (MIC) of 16 common antibiotics to 57 strains.Results Seventeen PFGE types were identified among the 77 Salmonella strains including three predominant types (P4, P6 and P8) and were grouped into three major pulsotypes (Cluster1-3) at 90% similarity level.The predominant types causing outbreaks of Salmonella enteritidis infection were P8, P6, P4 and P14, which were responsible for five cases of food poisoning.These isolated strains were highly resistant to nalidixic acid (93%), followed by resistance towards ampicillin (74%) and streptomycin (54%).Forty-one strains were resistant to three or more antibiotics (71.93%).Conclusion The PFGE types of Salmonella enteritidis strains isolated in Longyan city exhibit polymorphism and are clustered into three major pulsotypes.PFGE molecular typing can provide early-warning of sporadic outbreaks and help to identify the sources of infections in Salmonella enteritidis-related food poisoning.Attentions should be paid to multidrug resistant Salmonella enteritidis.Surveillance for multidrug resistant strains and usage of antibiotics should be strengthened.
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Objective To analyze the genetic characteristics of echovirus type 25( Echo25) strains isolated from patients with viral encephalitis in Longyan city. Methods Cerebrospinal fluid(CSF) specimens were collected from hospitalized patients with viral encephalitis or central nervous system infection in Longyan,2012. Enteroviruses(EV)were isolated from the specimens and then identified. Four strains of Echo25 were screened out by using serum neutralization test. Coding sequence of the VP1 region of the 4 Echo25 strains were amplified by RT-PCR and then sequenced. A phylogenetic tree was constructed to ana-lyze the nucleotide sequence homology between those sequences and the sequences of reference Echo25 strains available in the GenBank database. Results The VP1 nucleotide sequences of Echo25 strains isola-ted in Longyan were 498 bp in length,encoding 166 amino acid residues. The homology analysis showed that the VP1 nucleotide sequences of 3 strains were identical,sharing 97% homology in nucleotide with the rest strain. The Echo25 strains isolated in Longyan were highly similar to KJ957190( Beijing,2010)and HM031189(Henan,2008)strains. Phylogenetic analysis revealed that the Echo25 strains isolated in Longyan belonged to genotype B1. Conclusion Echo25 was one of the pathogens causing viral encephalitis in Longyan in 2012 and different transmission chains of Echo25 had emerged. This study indicates that it is necessary to strengthen the surveillance for EV and understand the genetic variation of the Echo25 for provi-ding better supportive evidences for the prevention and control of related diseases.
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This study aimed to analyse the genetically characterize isolates of Echovirus 11 from Longyan City,Fujian Province,and to reveal their genetic relationships with other isolates from China and abroad. Cerebrospinal fluid specimens from patients diagnosed with viral encephalitis or central nervous system (CNS) infections were collected from Longyan First Hospital between January and December 2011. Seven Echo11 strains were isolated and identified using the RIMV serum panel. The entire VP1 coding regions of four strains were sequenced and typed as Echo11 by an online blast program and,subsequently, phylogenet- ic analyses of the VP1 sequences of these stains and others published on GenBank were conducted. There were 600 nucleotides (nt) in each complete VP1 coding region that encoded 200 amino acids (aa). Among those four Echo11 strains, the sequence identities of nt and aa were 100% and 99%-100% respectively. And phylogenetic analyses indicate belong to subtype DS, the homology compared with DS strain (GU393713) were 93% (nt) and 99% (aa). The sequence identities for the nt and aa were 75%-76% and 90%, respectively, between the current isolates from Longyan and the Gregory prototype strain found in 1953. The sequence identity of nt and aa between the Longyan virus strains and the domestic Shandong strains isolated in 2010 were lower, at 74% and 88%-89%, respectively. However,the highest level of ho- mology was found when the Longyan strains were compared with the Netherlands strain (GU393773) found in 2007 (nt and aa identity: 94%-95% and 98%-99%, respectively). The relatively low levels of similarity between domestic isolates suggest that different transmission routes exist for Echo11 in mainland China.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Amino Acid Sequence , Base Sequence , Chin , China , Encephalitis, Viral , Virology , Enterovirus B, Human , Chemistry , Classification , Genetics , Enterovirus Infections , Virology , Genotype , Molecular Sequence Data , Phylogeny , Sequence Alignment , Viral Proteins , Chemistry , GeneticsABSTRACT
OBJECTIVE To investigate distribution and drug resistance status of infections in urinary system and offer scientific basis for reasonable usage of antibiotics. METHODS Totally 258 isolates collected from urinary infection specimens were identified and drug susceptibility test was performed. RESULTS Escherichia coli rated the top one,73.3%.The isolates were susceptible to imipenem and amikacin.The resistant rate to other 6 antibiotics were above 50%. CONCLUSIONS The drug resistance rate of isolates collected from urinary infection specimens goes upward,so we should pay attention to.
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Objective:To investigate the water soluble chemical constituent from Tribulus terrestris L..Methods:The raw material was extracted by 80% ethanol and the compound was isolated by means of chromatography on silica gel column.The structure of compound was elucidated by spectral analysis (UV,IR, 1HNMR, 13 CNMR,DEPT,2D-NMR,MS).Results and Conclusion:A water soluble constituent has been isolated from Tribulus terrestris L..Based on the spectroscopic data,it is identified as a new organic acid named terrestric acid (6-amino-4-oxo-1,2,3,4-tetrahydro-1,3,5-triazine-2-carboxylic acid).