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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Molecular detection of enterotoxins E, G, H and I in Staphylococcus aureus and coagulase-negative staphylococci isolated from clinical samples of newborns in Brazil

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Author(s):
Vasconcelos, N. G. [1] ; Pereira, V. C. [1] ; Araujo Junior, J. P. [1] ; da Cunha, M. de L. R. S. [1]
Total Authors: 4
Affiliation:
[1] UNESP Univ Estadual Paulista, Inst Biosci, Dept Microbiol & Immunol, BR-18618970 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of Applied Microbiology; v. 111, n. 3, p. 749-762, SEP 2011.
Web of Science Citations: 22
Abstract

Aims: The objective of this study was to investigate the detection of SEE, SEG, SEH and SEI in strains of Staphylococcus aureus and coagulase-negative staphylococci (CNS) using RT-PCR. Methods and Results: In this study, 90 Staph. aureus strains and 90 CNS strains were analysed by PCR for the detection of genes encoding staphylococcal enterotoxins (SE) E, G, H and I. One or more genes were detected in 54 (60%) Staph. aureus isolates and in 29 (32.2%) CNS isolates. Staphylococcus epidermidis was the most frequently isolated CNS species (n = 64, 71.1%), followed by Staphylococcus warneri (n = 8, 8.9%) and other species (Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus lugdunensis, Staphylococcus simulans, Staphylococcus saprophyticus and Staphylococcus xylosus: n = 18, 20%). The genes studied were detected in Staph. epidermidis, Staph. warneri, Staph. haemolyticus, Staph. hominis, Staph. simulans and Staph. lugdunensis. The highest frequency of genes was observed in Staph. epidermidis and Staph. warneri, a finding indicating differences in the pathogenic potential between CNS species and highlighting the importance of the correct identification of these micro-organisms. RT-PCR used for the detection of mRNA revealed the expression of SEG, SEH and/or SEI in 32 (59.3%) of the 90 Staph. aureus isolates, whereas expression of some of these genes was observed in 10 (34.5%) of the 90 CNS isolates. Conclusions: Staphylococcus epidermidis was the most toxigenic CNS species. Among the other species, only Staph. warneri and Staph. lugdunensis presented a positive RT-PCR result. PCR was efficient in confirming the toxigenic capacity of Staph. aureus and CNS. Significance and Impact of the Study: This study permitted to confirm the toxigenic capacity of CNS to better characterize the pathogenic potential of this group of micro-organisms. In addition, it permitted the detection of SEG, SEH and SEI, enterotoxins that cannot be detected by commercially available immunological methods. (AU)

FAPESP's process: 05/02293-9 - Determination of the enterotoxigenicity in Staphylococcus by RT-PCR method
Grantee:Maria de Lourdes Ribeiro de Souza da Cunha
Support Opportunities: Regular Research Grants