Analysis of identification and antibiotic susceptibility of isolates identified as Streptococcus pneumoniae by routine methods with negative quellung reaction results / 中华实用儿科临床杂志
Chinese Journal of Applied Clinical Pediatrics
; (24): 595-599, 2020.
Article
in Zh
| WPRIM
| ID: wpr-864061
Responsible library:
WPRO
ABSTRACT
Objective:
To determine whether these Streptococcus pneumoniae isolates identified by routine cli-nical methods that cannot be serotyped by the quellung reaction contain other species of viridans group streptococci and to determine the antibiotic susceptibility to provide reference for clinical medicine.Methods:
A total of 105 isolates identified as Streptococcus pneumoniae by routine methods with negative quellung reaction results were enrolled in this study.Multilocus sequence analysis (MLSA) and matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS) were used to identify species of these isolates.Broth microdilution method was used to detect susceptibilities of 14 antibiotics.Results:
Twenty-four of the 105 isolates were identified as Streptococcus pseudopneumoniae by MLSA, and the remaining 81 were Streptococcus pneumoniae.Six isolates of Streptococcus pseudopneumoniae were misidentified as Streptococcus pneumoniae, and 3 isolates as Streptococcus mitis/ oralis by MALDI-TOF-MS; and 6 isolates of Streptococcus pneumoniae were misidentified as Streptococcus pseudopneumoniae.All isolates were susceptible to Vancomycin, Levofloxacin and Moxifloxacin.The non-susceptibility rates between Streptococcus Pneumoniae and Streptococcus pseudopneumoniae against Ceftriaxone(28.4% vs.58.4%), Chloramphenicol(39.5% vs.4.2%), Erythromycin(77.8% vs.95.8%) and Azithromycin(75.3% vs.95.8%) were obviously different.Conclusions:
Routine clinical methods may misidentify some Streptococcus pseudopneumoniae as Streptococcus pneumoniae, and so does the MALDI-TOF-MS.In addition, Streptococcus pneumoniae isolates with negative results of the quellung reaction showed differences in antimicrobial resistance.And misidentification may affect the evaluation of pathogenic bacteria and antibiotic resistance.
Full text:
1
Index:
WPRIM
Type of study:
Diagnostic_studies
Language:
Zh
Journal:
Chinese Journal of Applied Clinical Pediatrics
Year:
2020
Type:
Article