Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. ...Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. aureus （MRSA） from methicillin-sensitive S. aureus （MSSA）. Methods A total of 100 5. aureus strains isolated from clinical specimens and farm workers were collected and analyzed by MALDI-TOF-MS. And data obtained were interpreted with biotyper software. Results Ninety-two strains were identified by MALDI-TOF-MS as 5. aureus at a level of secure genus and probable species, and 4 strains were identified at probable genus after their cultivation, spectral collection and data preprocessing. One strain was identified as 5. aureus with lower score. It was revealed that identification of 5. aureus by MALDI-TOF-MS was highly correlated with typing by biochemical and serological methods with an accuracy as high as 97%. The biotyper cluster analysis showed that 100 isolates were divided into 2 types at the distance level of 400. Higher peak intensity in the mass of both 3784 Da and 5700 Da was observed in MRSA, whereas that was absent from MSSA. Conclusion MALDI-TOF-MS is considered as a simple, high-throughput and accuracy for the identification of S from MSSA. rapid and highly reproducible technique with aureus and it can reliably differentiate MRSA展开更多
Objective:To investigate the infection of hospital-and community-acquired"erythromycininduced clindamycin resistant"strains or D-test positives of clinical isolates of Staphylococcus aureus(S.aureus)(with an...Objective:To investigate the infection of hospital-and community-acquired"erythromycininduced clindamycin resistant"strains or D-test positives of clinical isolates of Staphylococcus aureus(S.aureus)(with and without methicillin resistance)in a hospital.Methods:Strains of S.aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling.Results:Of the total 278 isolates,140(50.35%)were D-test positives and the rest were D-test negatives.Further,of 140(100%)pesitives,87(62.14%)and 53(37.85%)strains were from males and females,respectively.Of 140(100%)pesitives,117(83.57%)were methicillin resistant S.aureus and23(16.42%)were methicillin sensitive S.aureus;of 140 strains,103(73.57%)strains front persons with and 37(26.42%)were without related infections;of 140 strains,91(65%)and 49(35%)were from hospital-and community-acquired samples,respectively.In 140 strains,118(84.28%)with comorbidities and 22(15.71%)without comorbidities cases were recorded;similarly,persons with prior antibiotic uses contributed 108(77.14%)and without 32(22.85%)positive strains.These binary data of surveillance were analyzed by a univariate analysis.It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity,corroborated by low P values,P=0.001 1 and 0.0024,respectively.All isolates(278)were resistant to17 antibiotics of nine groups,in varying degrees;the minimum of 28%resistance for vancomycin and the maximum of 97%resistance for gentamicin were recorded.Further,of 278 strains,only42(15.1%)strains were resistant constitutively to both antibiotics,erythromycin resistant and clindamycin resistant,while 45(16.2%)strains were constitutively sensitive to both antibiotics(erythromycin sensitive,and clindamycin sensitive).Further,of the rest 191(68.7%)strains were with erythromycin resistant and clindamycin resistant,of which only 140(50.35%)strains were D-test positives,while the rest 51(18.34%)strains were D-test negatives.Conclusions:In view of high prevalence of D-test positive S.aureus strains,and equally high prevalence of multidrug resistant strains both in community and hospital sectors,undertaking of D-test may be routinely conducted for suppurative infections.展开更多
文摘Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. aureus （MRSA） from methicillin-sensitive S. aureus （MSSA）. Methods A total of 100 5. aureus strains isolated from clinical specimens and farm workers were collected and analyzed by MALDI-TOF-MS. And data obtained were interpreted with biotyper software. Results Ninety-two strains were identified by MALDI-TOF-MS as 5. aureus at a level of secure genus and probable species, and 4 strains were identified at probable genus after their cultivation, spectral collection and data preprocessing. One strain was identified as 5. aureus with lower score. It was revealed that identification of 5. aureus by MALDI-TOF-MS was highly correlated with typing by biochemical and serological methods with an accuracy as high as 97%. The biotyper cluster analysis showed that 100 isolates were divided into 2 types at the distance level of 400. Higher peak intensity in the mass of both 3784 Da and 5700 Da was observed in MRSA, whereas that was absent from MSSA. Conclusion MALDI-TOF-MS is considered as a simple, high-throughput and accuracy for the identification of S from MSSA. rapid and highly reproducible technique with aureus and it can reliably differentiate MRSA
基金supported by the research scheme from CSIR(New Delhi),No.21(0859)/11/EMR-11
文摘Objective:To investigate the infection of hospital-and community-acquired"erythromycininduced clindamycin resistant"strains or D-test positives of clinical isolates of Staphylococcus aureus(S.aureus)(with and without methicillin resistance)in a hospital.Methods:Strains of S.aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling.Results:Of the total 278 isolates,140(50.35%)were D-test positives and the rest were D-test negatives.Further,of 140(100%)pesitives,87(62.14%)and 53(37.85%)strains were from males and females,respectively.Of 140(100%)pesitives,117(83.57%)were methicillin resistant S.aureus and23(16.42%)were methicillin sensitive S.aureus;of 140 strains,103(73.57%)strains front persons with and 37(26.42%)were without related infections;of 140 strains,91(65%)and 49(35%)were from hospital-and community-acquired samples,respectively.In 140 strains,118(84.28%)with comorbidities and 22(15.71%)without comorbidities cases were recorded;similarly,persons with prior antibiotic uses contributed 108(77.14%)and without 32(22.85%)positive strains.These binary data of surveillance were analyzed by a univariate analysis.It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity,corroborated by low P values,P=0.001 1 and 0.0024,respectively.All isolates(278)were resistant to17 antibiotics of nine groups,in varying degrees;the minimum of 28%resistance for vancomycin and the maximum of 97%resistance for gentamicin were recorded.Further,of 278 strains,only42(15.1%)strains were resistant constitutively to both antibiotics,erythromycin resistant and clindamycin resistant,while 45(16.2%)strains were constitutively sensitive to both antibiotics(erythromycin sensitive,and clindamycin sensitive).Further,of the rest 191(68.7%)strains were with erythromycin resistant and clindamycin resistant,of which only 140(50.35%)strains were D-test positives,while the rest 51(18.34%)strains were D-test negatives.Conclusions:In view of high prevalence of D-test positive S.aureus strains,and equally high prevalence of multidrug resistant strains both in community and hospital sectors,undertaking of D-test may be routinely conducted for suppurative infections.
