Community-acquired methicillin-resistant Staphylococcus aureus from skin and soft tissue infections (in a sample of Egyptian population): analysis of mec gene and staphylococcal cassette chromosome.

Abstract

BACKGROUND:

Staphylococcus aureus has been recognized as an important pathogen associated with inpatients and community infections. Community-acquired methicillin-resistant S. aureus (CA-MRSA) infections commonly present as skin and soft-tissue infections (SSTIs). Treatment often includes incision and drainage with or without adjunctive antibiotics.

OBJECTIVES:

This study aimed to identify CA-MRSA infections both phenotypically and genotypically, to determine their spectrum of antibiotic resistance, and to establish the best scheme for molecular distinction between hospital-acquired MRSA (HA-MRSA) and CA-MRSA by staphylococcal cassette chromosome mec (SCCmec) typing and detection of Panton Valentine leukocidin (PVL).

MATERIALS:

50 swabs, from skin and soft tissue of infected lesions of outpatients attending the dermatology department of the Medical School, Alexandria University, were collected. Additionally, a nasal swab was taken from every participant.

METHODS:

Collection of swabs from the infected skin and soft tissues, followed by laboratory testing to phenotypically and genotypically identify MRSA. Also, nasal swabs were taken from every patient to identify MRSA colonization.

RESULTS:

Staphylococcus aureus strains were identified in 38 (76%) of the 50 clinical isolates. 18 (47.37%) out of the 38 S. aureus strains were resistant to oxacillin and cefoxitin discs, were penicillin binding protein 2a (PBP2a) producers, and were initially diagnosed as MRSA. All of the 18 strains were definitively diagnosed as MRSA by mecA gene detection using real time PCR, while only six (33.33%) strains were PVL positive. Using the sets of primers of Zhang et al.: nine (50%) out of the 18 CA-MRSA strains were SCCmec type V, and one (5.56%) was SCCmec type IVc. Then, using the set of primers by Oliveira et al., two (25%) out of the eight untypable MRSA strains were found to be SCCmec type IV, and six (75%) remained untypable.

CONCLUSIONS:

CA-MRSA must be considered when treating skin and soft tissue infections, especially in developing countries. Empirical use of agents active against CA-MRSA is warranted for patients presenting with serious SSTIs.

• Authors: Nagat Sobhy, Fatma Aly, Ola Abd El Kader, Abeer Ghazal, Amira Elbaradei
• Journal: The Brazilian journal of infectious diseases : an official publication of the Brazilian Society of Infectious Diseases (Braz J Infect Dis) 2012 Sep-Oct Vol. 16 Issue 5 Pg. 426-31 ISSN: 1678-4391 [Electronic] Brazil
• PMID: 22964294 (Publication Type: Journal Article)
• Copyright: Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• Bacterial Proteins
• Bacterial Toxins
• Exotoxins
• Leukocidins
• Panton-Valentine leukocidin
• Penicillin-Binding Proteins
• mecA protein, Staphylococcus aureus

Topics

• Adolescent
• Adult
• Anti-Bacterial Agents (pharmacology)
• Bacterial Proteins (genetics)
• Bacterial Toxins (genetics)
• Child
• Child, Preschool
• Community-Acquired Infections (microbiology)
• Exotoxins (genetics)
• Female
• Genotype
• Humans
• Leukocidins (genetics)
• Male
• Methicillin-Resistant Staphylococcus aureus (drug effects, genetics)
• Microbial Sensitivity Tests
• Penicillin-Binding Proteins
• Phenotype
• Soft Tissue Infections (microbiology)
• Staphylococcal Skin Infections (microbiology)
• Young Adult