Genetic analysis of Penthorum chinense Pursh by improved RAPD and ISSR in China

Background: Penthorum chinense Pursh (P. chinense) is a well-known traditional Chinese medicine (TCM) plant, which has long been used for the prevention and treatment of hepatic diseases. This study aimed to genetically characterize the varieties of P. chinense from different geographic localities of China by random amplification of polymorphic DNA (RAPD)-PCR technique and verified with inter-simple sequence repeat (ISSR) markers. Results: The P. chinense samples were collected from nine different geographic localities. Previously improved RAPD and ISSR markers were utilized for genetic analysis using DNA amplification. The genetic relationship dendrogram was obtained by conducting cluster analysis to the similarity coefficient of improved RAPD and ISSR markers. Improved RAPD yielded 185 scorable amplified products, of which 68.6% of the bands were polymorphic, with an average amplification of 9.25 bands per primer. The ISSR markers revealed 156 alleles with 7.8 bands per primers, where 59.7% bands were polymorphic. Furthermore, the similarity coefficient ranges of RAPD and ISSR markers were 0.71­0.91 and 0.66­0.89, respectively. Conclusions: This study indicated that improved RAPD and ISSR methods are useful tools for evaluating the genetic diversity and characterizing P. chinense. Our findings can provide the theoretical basis for cultivar identification, standardization, and molecular-assisted breeding of P. chinense for medicinal use.

Genetic relationship between Escherichia coli strains isolated from dairy mastitis and from the stable fly Stomoxys calcitrans / Caracterização genotípica de Escherichia coli isolados de leite com mastite e da mosca dos estábulos Stomoxys calcitrans

The stable fly Stomoxys calcitrans (Linnaeus, 1758) has been described as a potential spreader of infectious agents to cattle herds. Among the agents transmitted by this fly, Escherichia coli has attracted attention due to its potential to cause gastrointestinal disorders as well as environmental mastitis in dairy cows. Therefore, the aim of this study was to isolate and to assess the genetic diversity and the clonal relatedness among E. coli isolates from the milk of dairy mastitis and from stable flies anatomical sites by the Random Amplification of Polymorphic DNA (RAPD-PCR) technique. The molecular typing revealed a high degree of genetic polymorphism suggesting that these microorganisms have a non-clonal origin. Identical electrophoretic profiles were observed between E. coli isolates from different flies, different mammary quarters of the same cow and from cows on a single farm. These results reveal the circulation of the same bacterial lineages and suggest the role of the stable fly in bacterial dispersion. Considering the high pathogenic potential of this bacterial species, our findings alert to a more effective health surveillance.(AU)

A mosca dos estábulos Stomoxys calcitrans é descrita como um importante dispersor de agentes infecciosos aos bovinos. Dentre os agentes veiculados por esta mosca a bactéria Escherichia coli ganha relevância devido ao seu potencial em desenvolver alterações gastroentéricas, bem como mastite bovina ambiental. Desta forma, objetiva-se com este estudo isolar e acessar a diversidade genética e relação de clonalidade entre isolados de E. coli provenientes de casos de mastite e de moscas dos estábulos utilizando a técnica da Amplificação Randômica do DNA Polimórfico (RAPD). A tipagem molecular revelou elevado polimorfismo genético sugerindo que esses microrganismos têm origem não clonal. Perfis eletroforéticos idênticos entre si foram observados entre amostras isoladas de diferentes moscas, quartos mamários de uma mesma vaca, bem como de diferentes vacas dentro de uma mesma propriedade. Esses resultados revelam a circulação de uma mesma linhagem bacteriana e sugerem o papel da Stomoxys calcitrans na dispersão bacteriana. Considerando o elevado potencial patogênico dessa espécie bacteriana, nossos achados alertam para uma vigilância sanitária mais efetiva.(AU)

Antibiotic Resistance and Molecular Epidemiology Profile of Staphylococcus aureus in Hospital-acquired Infection / 中华医院感染学杂志

OBJECTIVE To identify the pop strain of Staphylococcus aureus hospital acquired infection by random amplification of polymorphic DNA(RAPD),and to study the molecular mechanism of antibiotic(resistance),so as to reduce the occurrence of drug resistance and infection acquired in hospital.METHODS 1.DNA from 21 strains of S.aureus were extracted by the phenol-chloroform method and analyzed by using arbitrary(primer) polymerase chain reaction(AP-PCR).2.Amplifying mecA,GyrA and GrlA by PCR,and testing the(variation) of these genes by using Hinf Ⅰ-digested analysis.RESULTS Twenty one S.aureus strains were divided into 3(genetic) types.Type Ⅰ is the pop strain in our hospital which including 12 strains.Fourteen from 17 clinical stains were resistant to meticillin and quinolones,of which 13 strains had mecA except isolate 13064.And they all had(variation) in(GyrA) and/or GrlA.CONCLUSIONS RAPD provides markers for the typing of clinical strains and is suitable for(molecular) epidemiologic studies with high type ability,powerful discrimination,simplicity and(rapidness). Type Ⅰ is the pop S.aureus strain in hospital-acquired infection of our hospital.The majority of these strains are multi-(resistant) to meticillin,quinolones and other antibiotics.

Outbreak of Nosocomial Urinary Tract Infections caused by Multidrug-Resistant Pseudomonas aeruginosa / 병원감염관리

BACKGROUND: Nosocomial urinary tract infection (UTI) accounts for 35% of the nosocomial infection and 80-90% of them are associated with urethral catheters. Recently, we experienced an outbreak of nosocomial UTI caused by multidrug-resistant Pseudomonas aeruginosa in neurosurgical intensive care unit (NSICU). METHODS: We investigated clinical records of the patients and observed the methods of care of urethral catheters in NSICU. Identification of P. aeruginose was done by API NE (API system; bioMerieux, France) and antibiotic susceptibility tests were done by disk diffusion method. Random Amplification of Polymorphic DNA (RAPD) assay was used as a genotyping method. RESULTS: Between November 1997 and January 1998, 11 P. aeruginosa strains were isolated from the urine of 11 patients hospitalized in NSICU of Kangnam St. Mary's Hospital. Routine regular bladder irrigation, and emptying urine with common urinal had been done falsely. Antibiogram of the isolates showed resistance to multiple antibiotics including imipenem, gentamicin. amikacin, piperacillin, ciprofloxacin, ceftazidime, and cefoperazone/sulbactam. RAPD of the outbreak strains showed clonal relatedness, which was different from those of other clinical strains, We instructed all the health care workers to stop bladder Irrigation, and to use the separate urinals for each patient. Thereafter, no further case of P. aeruginosa UTI has occurred. CONCLUSION: An outbreak of UTI, caused by a single clone of P. aeruginosa, was confirmed by RAPD and was eradicated after correction of false practice on care-of urinary catheter.

Genetic diversity in Fluconazole-resistant and -susceptible oral Candida albicans isolated from patients with Sjgren's syndrome / 实用口腔医学杂志

Objective:To analyze genetic diversity of Fluconazole(FLZ)-resistant and -susceptible Candida albicans(C. albicans) strains isolated from patients with Sjgren's Syndrome (SS). Methods:30 C.albicans strains were isolated from the patients with SS and identified using standard criteria. Microdilution method was performed to determine the minimum inhibitory concentrations (MICs) of C.albicans to FLZ. A composite genotype was generated for each strain through random amplification of polymorphic DNA (RAPD) using three different primers, RSD10, RSD11 and RSD12. Results:The DNA fingerprinting profiles indicated genetic diversity amongst both the FLZ-resistant as well as -susceptible isolates, and no specific features emerged distinguishing the drug-resistant and -susceptible groups. Conclusion:These observations cast doubt on the theory of a clonal origin of FLZ-resistant C. albicans isolates. The emergence of FLZ resistance in SS patients may be associated with continuous exposure to FLZ.