Virulence Factors of Staphylococcus aureus Isolates in an Iranian Referral Children's Hospital

Abstract

ObjectivesThe clinical importance of Staphylococcus aureus (S. aureus) is attributed to notable virulence factors, surface proteins, toxins, and enzymes as well as the rapid development of drug resistance. The aim of this study was to compare the occurrence of virulence factors produced by S. aureus strains isolated from children in an Iranian referral children's hospital.MethodsThe presence of genes encoding for the enterotoxins A (sea), B (seb), C (sec), D (sed), TSST-1 (tsst), exfoliative toxin A (eta), and exfoliative toxin B (etb) were detected by Multiplex polymerase chain reaction (PCR) using specific primers. In addition, the standardized Kirby-Bauer disc-diffusion method was performed on Mueller-Hinton agar.ResultsIn total, 133 S. aureus isolates were obtained from different patients. Of these S. aureus isolates, 64 (48%) were methicillin-resistant S. aureus (MRSA), and all of these tested positive for the mecA gene. Regarding the classical enterotoxin genes, sea gene (40.6%) was the most prevalent followed by seb (19.6%), tsst (12.8%), eta (11.3%), etb (9%), sed (4.5%), and sec (3%). Among methicillin-susceptible S. aureus (MSSA) isolates, seb and tsst were the more prevalent toxins in comparison with MRSA isolates (p < 0.05), while the frequency of sea, sed, eta, and etb genes were higher among MRSA isolates (p > 0.05).ConclusionIn our study enterotoxin A was produced by 40.6% of the isolates (48% from MRSA and 33% from MSSA isolates) which was higher than in previous reports. According to our results, strict hygiene and preventative measures during food processing are highly recommended.

Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

“…However, high detection frequencies of eta (11.3%) and etb (9%) were reported in Sabouni study [29] and almost the same incidence was reported in other studies [6,30,31]. This may be sensible because none of the MRSA strains in the current survey was isolated from children with skin diseases including staphylococcal scalded skin syndrome (SSSS), impetigo, or blisters.…”

Correlation of methicillin resistance and virulence genes of <i>Staphylococcus aureus</i> with infection types and mode of acquisition in Sofia, Bulgaria

“…There are wide differences in the reported geographical distribution of MRSA, from 2.9% to 8.7 % in Turkish nasal carriers and respiratory tracts of ill persons (3, 23), up to 38.7% in Colombia (16), 39.6% in India (24), 41-48% in Iran (25,26) and 44% in Nigeria from animal samples (27). The methicillin resistance rate observed in this study was 12%, with 7.7% from outpatients and 16.2% from inpatients.…”

Quorum Sensing: A Prospective Therapeutic Target for Bacterial Diseases

“…The virulence factors produced by different strains are different. For example, Gram-negative Pseudomonas aeruginosa produces virulence factors, such as pyocyanin, elastase, lectin, and exotoxin A [47,48], and Gram-positive Staphylococcus aureus produces virulence factors such as fibronectin binding protein, hemolysin, protein A, lipase, and enterotoxin [49,50]. Studies have shown that the production of these virulence factors is regulated by the bacterial QS signaling systems [51,52].…”