Abstract
Detection of meticillin resistance in Staphylococcus aureus isolates continues to be a challenge. Clinical specimens obtained from abscesses from two epidemiologically unrelated outpatients were positive for meticillin-resistant S. aureus (MRSA) by a commercial PCR assay, but colonies obtained by culture were susceptible to oxacillin by an automated testing method. The colonies were also negative using a penicillin-binding protein 2a (PBP2a) latex agglutination test. Because of the discrepancy between the genotypic and phenotypic results, both isolates were re-tested by PCR, disc diffusion, VITEK® 2 and MicroScan1 and were plated on chromogenic agar. Both isolates also underwent cefoxitin induction for additional susceptibility testing studies. Following overnight induction with cefoxitin, both isolates demonstrated resistance to oxacillin and cefoxitin by the two automated methods and by disc diffusion, and were positive using PBP2a latex agglutination tests. Population analysis failed to identify heteroresistant subpopulations in uninduced isolates. Identifying the presence of MRSA by PCR directly in the specimens was critical for determining the appropriate course of antimicrobial therapy for the patients. Both infections resolved with non-b-lactam therapy.
| Original language | English |
|---|---|
| Pages (from-to) | 79-83 |
| Number of pages | 5 |
| Journal | Journal of Global Antimicrobial Resistance |
| Volume | 1 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 2013 |
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All Science Journal Classification (ASJC) codes
- Immunology
- Microbiology
- Immunology and Allergy
- Microbiology (medical)
Cite this
Wound infections caused by inducible meticillin-resistant Staphylococcus aureus strains. / Penn, Christopher; Moddrell, Carol; Tickler, Isabella A.; Henthorne, Mary Ann; Kehrli, Megan; Goering, Richard V.; Tenover, Fred C.
In: Journal of Global Antimicrobial Resistance, Vol. 1, No. 2, 06.2013, p. 79-83.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Wound infections caused by inducible meticillin-resistant Staphylococcus aureus strains
AU - Penn, Christopher
AU - Moddrell, Carol
AU - Tickler, Isabella A.
AU - Henthorne, Mary Ann
AU - Kehrli, Megan
AU - Goering, Richard V.
AU - Tenover, Fred C.
PY - 2013/6
Y1 - 2013/6
N2 - Detection of meticillin resistance in Staphylococcus aureus isolates continues to be a challenge. Clinical specimens obtained from abscesses from two epidemiologically unrelated outpatients were positive for meticillin-resistant S. aureus (MRSA) by a commercial PCR assay, but colonies obtained by culture were susceptible to oxacillin by an automated testing method. The colonies were also negative using a penicillin-binding protein 2a (PBP2a) latex agglutination test. Because of the discrepancy between the genotypic and phenotypic results, both isolates were re-tested by PCR, disc diffusion, VITEK® 2 and MicroScan1 and were plated on chromogenic agar. Both isolates also underwent cefoxitin induction for additional susceptibility testing studies. Following overnight induction with cefoxitin, both isolates demonstrated resistance to oxacillin and cefoxitin by the two automated methods and by disc diffusion, and were positive using PBP2a latex agglutination tests. Population analysis failed to identify heteroresistant subpopulations in uninduced isolates. Identifying the presence of MRSA by PCR directly in the specimens was critical for determining the appropriate course of antimicrobial therapy for the patients. Both infections resolved with non-b-lactam therapy.
AB - Detection of meticillin resistance in Staphylococcus aureus isolates continues to be a challenge. Clinical specimens obtained from abscesses from two epidemiologically unrelated outpatients were positive for meticillin-resistant S. aureus (MRSA) by a commercial PCR assay, but colonies obtained by culture were susceptible to oxacillin by an automated testing method. The colonies were also negative using a penicillin-binding protein 2a (PBP2a) latex agglutination test. Because of the discrepancy between the genotypic and phenotypic results, both isolates were re-tested by PCR, disc diffusion, VITEK® 2 and MicroScan1 and were plated on chromogenic agar. Both isolates also underwent cefoxitin induction for additional susceptibility testing studies. Following overnight induction with cefoxitin, both isolates demonstrated resistance to oxacillin and cefoxitin by the two automated methods and by disc diffusion, and were positive using PBP2a latex agglutination tests. Population analysis failed to identify heteroresistant subpopulations in uninduced isolates. Identifying the presence of MRSA by PCR directly in the specimens was critical for determining the appropriate course of antimicrobial therapy for the patients. Both infections resolved with non-b-lactam therapy.
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U2 - 10.1016/j.jgar.2013.03.009
DO - 10.1016/j.jgar.2013.03.009
M3 - Article
VL - 1
SP - 79
EP - 83
JO - Journal of Global Antimicrobial Resistance
JF - Journal of Global Antimicrobial Resistance
SN - 2213-7165
IS - 2
ER -