ABSTRACT
We aimed to identify the infectious source of a case of melioidosis,to provide evidence for the prevention and control of melioidosis in Shanxi Province,China.The patient developed repeated fever,fatigue,diarrhea,and other symptoms after being caught in the rain while traveling in Hainan Province.The blood culture was positive,and the bacterial strain was i-dentified as Burkholderia thayensis and sent to the provincial Center for Disease Control and Prevention for further evaluation.MALDI-TOF MS and biochemical identification were used to identify the strain,whole genome sequencing was performed after nucleic acid extraction,MLST type and drug-resistance genes were analyzed,and a phylogenetic tree was constructed.The iso-lated strain was identified as Burkholderia pseudomallei by MALDI-TOF MS and biochemistry,and the MLST type was 366.The whole gene sequencing analysis indicated a close evolutionary relationship with the three isolates in Hainan Province,with high homology.This case of melioidosis was indeed imported from Hainan Province,according to molecular tracing analysis and epidemiological investigation,thus suggesting that medical institutions and disease control departments should strengthen understanding of melioidosis,and improve the diagnosis and treatment ability.
ABSTRACT
Objective@#To investigate the antimicrobial resistance status and pulsed field gel electrophoresis (PFGE) patterns of Salmonella enteritidis (S.enteritidis) in Shanxi Province in order to provide references for the treatment of Salmonella infection and for tracing the source of outbreaks of foodborne diseases.@*Methods@#Sixty-four S. enteritidis strains were collected by monitoring sites for foodborne diseases from April 2015 to March 2018. Biochemical identification system and serotyping analysis were used for bacterial identification. Drug susceptibility patterns were analyzed with micro-broth dilution method. PFGE was used for molecular typing.@*Results@#The antimicrobial resistance rate of 64 S. enteritidis strains to nalidixic acid (95.31%) was the highest, followed by that to ampicillin (90.63%) and to ampicillin/sulbactam (81.25%). They had lower resistance rates to cefazolin, cefotaxime, tetracycline, ceftazidime, trimethoprim/sulfamethoxzole and ciprofloxacin (3.13%-23.44%) and were all sensitive to chloramphenicol, cefotaxime, azithromycin, imipenem and gentamicin. No statistically significant difference in drug resistance rates was found between the sporadic strains and the outbreak strains (P>0.05). All 64 S. enteritidis strains digested with XbaⅠwere divided into 33 molecular patterns by PFGE. The numbers of bacteria contained in each pattern ranged from 1 to 10 strains. The similarity among patterns was between 54.6% and 100%.@*Conclusion@#More attention should be paid to the drug resistance status of S. enteritidis in Shanxi Province. It is necessary to strengthen the standardized administration of antibiotics. The PFGE patterns of S. enteritidis reveal the presence of significant genetic polymorphism. PFGE is of great significance in analyzing the genetic relationship among S. enteritidis strains and in identifying and tracing the source of outbreaks of foodborne diseases.