Molecular Epidemiological Study On An Outbreak Of Burkholderia Cepacia Nosocomial Bloodstream Infection

The morbidity of nosocomial infection is increasing now. The outbreak ofnosocomial infections (NI) is contribute to higher mortality rates, as well as toincreasing length of hospital stay and health care costs, make bad affluence. The keyof control the outbreak of nosocomial bloodstream infections is detect early andcontrol in time. Traditional type method include: biotyping, antimicrobialsusceptibility patterns, serotyping method and so on. They have so many deficiency:the poor discriminatory power, the more affect factor, the poor reproducibility and soon. It is important to apply molecular typing-method to investigate a nosocomialinfection outbreak, especially in quickly detecting the outbreak pathogen, pursuingthe source of infection, find out the path of transfer, adopt prevent and controlmeasurement in time.The study applies phenotyping method and genotyping method to investigate 28Burkholderia Cepacia isolates, which are an outbreak of nosocomial bloodstreaminfection after surgey recently. Discuss the value of apply molecular epidemiologicalmethod to invest an outbreak of Burkholderia Cepacia nosocomial bloodstreaminfection.Partâ… : Antimicrobial susceptibility typing of Burkholderia Cepacianosocomial bloodstream infection clinic isolateObjective: investigate antimicrobial susceptibility patterns of 28 BurkholderiaCepacia nosocomial bloodstream infection isolatesMethod: MICs (Minimum inhibition concentration) and K-B(Kirby-Bauer)antibacterial activity.Results: Sensitive for Levofloxacin, Ciprofloxacin, Ceftazidime, Piperacillin, Ceftriaxone, Imipenem, Meropenem, Trimethoprim-sulfamethoxazole, Minocycline;resistance for Gentamicin, Amikacin, Tetracycline; Cefoperazone/Sulbactamintermediate 20 isolates, resistance 8 isolates,Cefepime intermediate 24 isolates, resistance 4 isolates, Cefotaxime sensitive 24 isolates, intermediate 4 isolates. Thereis antimicrobial susceptibility difference among Cefoperazone/Sulbactam, Cefepimeand Cefotaxime. Partâ…¡: Apply recA genotyping to analyze Burkholderia Cepacia nosocomialbloodstream infection clinic isolatesObjective: To investigate antimicrobial susceptibility patterns of BurkholderiaCepacia nosocomial bloodstream infection isolatesMethod:1. recA PCR amplied2. apply PCR-RFLP with Haeâ…¢on recA PCR fragment3. nucleotide sequence analysis of recA PCR fragmentResults:All 28 clinic isolates of BSI have been amplified about 1043bp productswhich to be expected. RFLP patterns generated by digestion with Haeâ…¢of the recAPCR products is the same, and same with pattern J, B.stabilis(â…£). Analysisnucleotide sequence of recA PCR products, confirm they are B.stabilis(â…£).Partâ…¢: Apply PFGE analyse Burkholderia Cepacia nosocomial bloodstreaminfection isolatesObjective: apply PFGE to investigate Burkholdefia Cepacia nosocomial bloodstreaminfection isolates.Method: PFGE.Results: PFGE patterns generated by digestion with SpeI are the same type on clinicisolate B258 and B140. Use standard of Tenover, they are the same clone.Conclusion:1. The pathogen of the study is not MDR. Depend on the small difference ofCefoperazone/Sulbactam, Cefepime and Cefotaxime, 28 clinic isolates have sevenantimicrobial susceptibility patterns.2. Apply PCR-RFLP method to type gene recA of 28 clinic isolates, the result: all clinic isolates are positive of recA gene PCR amplified. Apply restriction enzymesHaeâ…¢analysis to recA gene PCR fragment, PCR-RFLP pattems are the same:pattem J, B.stabilis (â…£). The result is to be confirm by nucleotide sequenceanalysis ofrecA PCR product recA gene PCR fragment, they are B.stabilis (â…£).3. Random select sample B258 which has been analysis recA nucleotide sequenceand B140 which has not been analysis recA nucleotide sequence. PFGE patternsgenerated by digestion with SpeI are the same type. Conclude that B258 and B 140are the same clone.4. study of all above, antimicrobial susceptibility pattern type, PCR-RFLP type ofrecA,nucleotide sequence analysis of recA PCR product and PFGE, conclude thatthe case was an outbreak of nosocomial bloodstream infection, the pathogen isB.stabilis (â…£).5. Investigate outbreak of BCC nosocomial infection, recA gene's PCR-RFLP typeand PFGE type have the same result of type, they have important value ininvestgate on nosocomial bloodstream infection. From enconmy and ease ofproformance, recA gene's PCR-RFLP type have more value to apply.6. As pathogen, Burkholderia Cepacia Complex take more attention in nosocomialbloodstream infection.