Clonal Distribution and Antibiotic Susceptibility of Staphylococcus aureus from Pediatric Patients: 8-Year Trends in a Children's Hospital in Colombia

J Trop Pediatr. 2021 Dec 8;67(6):fmab105. doi: 10.1093/tropej/fmab105.

Abstract

Emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains in healthcare settings has changed the hospital epidemiology of MRSA in the last few years. Despite a global increase in MRSA frequency, infections caused by methicillin-susceptible S. aureus (MSSA) have persisted in healthcare settings and the community. Staphylococcus aureus isolates were collected between 2009 and 2017 at the Children's Hospital of a Caribbean city in South America. Methicillin-resistant isolates were subjected to SCCmec typing. Representative isolates were analyzed by multilocus sequence typing (MLST) and spa typing. Antibiotic susceptibility was assessed by agar dilution method. D-zone test was performed in erythromycin-resistant isolates to determine macrolide/lincosamide/streptogramin resistance. Spa typing revealed 10 different spa types. The main epidemic clones circulating during the study period were: ST8-MRSA-IVc, ST923-MRSA-IVa and ST8-MRSA-IVa. The study found high frequencies of PVL genes and resistance to erythromycin and clindamycin in the isolates. This study provides the first description of the population structure of MRSA and MSSA causing infections attended in the participating Children's Hospital. ST8-MRSA-IVc, ST923-MRSA-IVa and ST8-MRSA-IVa were the most prevalent in the isolate population.

Keywords: S. aureus; MRSA; MSSA; clonal complex; pediatric infection.

Plain language summary

This study was aimed to determine the distribution of sequence types, SCCmec types and antibiotic resistance profiles of MRSA and MSSA isolates recovered from pediatric patients with clinical infections attended in the Children’s Hospital of a Caribbean city in South America in a period spanning 8 years. We found high frequencies of PVL genes and resistance to erythromycin and clindamycin in the isolates. The fact that MRSA and MSSA isolates in this study were frequently resistant to erythromycin and clindamycin is an indication of the selective pressure imposed by the extensive use of these two antibiotics in the treatment of skin and soft tissue infections in the geographical area of this study. This is the first study reporting the clonal distribution of Staphylococcus aureus causing infections in the pediatric population of Cartagena, a tropical city in the Caribbean coast of Colombia.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Child
  • Colombia / epidemiology
  • Hospitals
  • Humans
  • Methicillin-Resistant Staphylococcus aureus* / genetics
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Staphylococcal Infections* / drug therapy
  • Staphylococcal Infections* / epidemiology
  • Staphylococcus aureus / genetics

Substances

  • Anti-Bacterial Agents