The spa Typing and Characterization of Nasal Carriage Methicillin-resistant Staphylococcus aureus Isolates From Healthy Children

Abstract

Background:The Methicillin-resistant Staphylococcus aureus (MRSA) strains cause wide spectrum infections in hospitals and are responsible for the majority of the communityacquired infections. The emergence of community-acquired MRSA in patients without risk factors represents a high risk for public health.Objectives: In this study, we aimed to molecular typing the nasal carriage MRSA strains harbored mecA gene isolated from healthy children living in the North of Iran and also to determine the pattern of vancomycin susceptibility in these isolates. Methods:The MRSA strains were identified using standard microbiological and molecular procedures. The antibiotic susceptibility test was performed according to the clinical and laboratory standards institute. The MRSA strains were characterized by spa typing. Results:In total, 14 different patterns of spa genes were obtained from MRSA isolates in this study, which included t790 (23.07%), t2962 (15.38%), t267 (15.38%), t159 (7.69%) and t701, t094, t1816, t11332, t937, t2135, t180, t160 [1 (3.84%) isolate per each type]. The rate of resistant isolates to cefoxitin, , cefalotin, clindamycin, cefazolin, co-amoxiclav, co-trimoxazole, and cephalexin antibiotics were 69.23%, 100%, 46.15%, 96.15%, 100%, 3.48%, and 100%, respectively. In total, six (23.07%) revealed vancomycin-intermediate resistant phenotype and five (19.23%) isolates revealed vancomycin-resistant S. aureus phenotype. Conclusions:This study showed the different variants of MRSA strains based on molecular typing, among healthy children. Continuous surveillance studies to monitor MRSA should be encouraged to gain a better understanding of the circulating MRSA strains and prevent community spread of this pathogen.

Characterization of methicillin-resistant Staphylococcus aureus through genomics approach

“…Many of these established techniques are costly and time-consuming, and the discriminatory abilities of these techniques are also different (Du et al 2011 ). However, the spa typing method has been considered as a rapid and inexpensive method for genotyping and it provides high discriminating power than other typing methods (Shittu et al 2011 ; O’Hara et al 2016 ; Goudarzi et al 2017 ; Ali et al 2019 ; Rezai et al 2019 ; Kareem et al 2020 ). Both phenotypic and molecular typing methods have been used widely to detect and differentiate several MRSA strains, but these techniques have certain limitations in infection control and investigating the nosocomial transmission as these techniques provide low resolution and more time-consuming.…”

Molecular Epidemiology, Virulence Factors, Antibiotic Resistance and Risk Factors for Nasal Carriage of Staphylococcus aureus in A Teenage Student Population: High Prevalence of Oxacillin Susceptible MRSA Isolates

“…Most prevalent circulating spa type in Iran, t037 was not observed among our isolates. In a similar study conducted on OR-MRSA isolates collected from healthy children in Iran, the spa types t790, t267, and t2962 were found to be the most common types, and the spat type11332 were identified in 3.83% of isolates (39).…”

Staphylococcal variable number tandem repeat (VNTR)-spa genotyping and their role in phylogenic study

“…It binds to immunoglobulins molecules, inhibits opsonization and phagocytosis mechanisms, and can act as a superantigen (Balachandran et al,2018). Genotyping of S. aureus is an important tool for investigating and detecting healthcare-associated infections and helps to control and prevent MRSA that causes hospital-acquired or community-acquired infections (Rezai et al,2020). This typing can be done depending on variable molecular typing procedures.…”