Comparative Genotypes, Staphylococcal Cassette Chromosome mec (SCCmec) Genes and Antimicrobial Resistance amongst Staphylococcus epidermidis and Staphylococcus haemolyticus Isolates from Infections in Humans and Companion Animals

PLoS One. 2015 Sep 17;10(9):e0138079. doi: 10.1371/journal.pone.0138079. eCollection 2015.

Abstract

This study compares the characteristics of Staphylococcus epidermidis (SE) and Staphylococcus haemolyticus (SH) isolates from epidemiologically unrelated infections in humans (Hu) (28 SE-Hu; 8 SH-Hu) and companion animals (CpA) (12 SE-CpA; 13 SH-CpA). All isolates underwent antimicrobial susceptibility testing, multilocus sequence typing and DNA microarray profiling to detect antimicrobial resistance and SCCmec-associated genes. All methicillin-resistant (MR) isolates (33/40 SE, 20/21 SH) underwent dru and mecA allele typing. Isolates were predominantly assigned to sequence types (STs) within a single clonal complex (CC2, SE, 84.8%; CC1, SH, 95.2%). SCCmec IV predominated among MRSE with ST2-MRSE-IVc common to both Hu (40.9%) and CpA (54.5%). Identical mecA alleles and nontypeable dru types (dts) were identified in one ST2-MRSE-IVc Hu and CpA isolate, however, all mecA alleles and 2/4 dts detected among 18 ST2-MRSE-IVc isolates were closely related, sharing >96.5% DNA sequence homology. Although only one ST-SCCmec type combination (ST1 with a non-typeable [NT] SCCmec NT9 [class C mec and ccrB4]) was common to four MRSH-Hu and one MRSH-CpA, all MRSH isolates were closely related based on similar STs, SCCmec genes (V/VT or components thereof), mecA alleles and dts. Overall, 39.6% of MR isolates harbored NT SCCmec elements, and ACME was more common amongst MRSE and CpA isolates. Multidrug resistance (MDR) was detected among 96.7% of isolates but they differed in the prevalence of specific macrolide, aminoglycoside and trimethoprim resistance genes amongst SE and SH isolates. Ciprofloxacin, rifampicin, chloramphenicol [fexA, cat-pC221], tetracycline [tet(K)], aminoglycosides [aadD, aphA3] and fusidic acid [fusB] resistance was significantly more common amongst CpA isolates. SE and SH isolates causing infections in Hu and CpA hosts belong predominantly to STs within a single lineage, harboring similar but variable SCCmec genes, mecA alleles and dts. Host and staphylococcal species-specific characteristics were identified in relation to antimicrobial resistance genes and phenotypes, SCCmec and ACME.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / therapeutic use
  • Bacterial Proteins / genetics
  • Cats
  • DNA, Bacterial / genetics
  • Dogs
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Horses
  • Humans
  • Interspersed Repetitive Sequences / genetics*
  • Methicillin Resistance / genetics
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Multilocus Sequence Typing
  • Oligonucleotide Array Sequence Analysis
  • Pets / microbiology*
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology
  • Staphylococcus epidermidis / drug effects
  • Staphylococcus epidermidis / genetics*
  • Staphylococcus epidermidis / isolation & purification
  • Staphylococcus haemolyticus / drug effects
  • Staphylococcus haemolyticus / genetics*
  • Staphylococcus haemolyticus / isolation & purification

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • DNA, Bacterial
  • MecA protein, Staphylococcus epidermidis

Associated data

  • GENBANK/KP265311
  • GENBANK/KP265312
  • GENBANK/KP265313
  • GENBANK/KP265314
  • GENBANK/KP265315

Grants and funding

The Mircobiology Research unit, Dublin Dental University Hospital provided all funding for staff, materials and DNA sequencing for this study apart from the mecA allele typing. The mecA Allele typing was undertaken and funded by S. Monecke and R. Ehricht at Alere Technologies GmbH. There was no external funding for this project.