Methicillin resistance and biofilm production of Staphylococcus epidermidis isolates from infectious and normal flora conjunctiva.
OBJECTIVE
Coagulase-negative staphylococci have been reported to be the most frequent cause of bacterial postoperative endophthalmitis. Biofilm formation is the major virulence factor of Staphylococcus epidermidis and is often associated with methicillin resistance. This study aims at evaluating the presence of biofilm-producing and methicillin resistance genes (mecA) in S. epidermidis.


METHODS
S. epidermidis isolated from clinically infected sites (group 1) and from normal human conjunctiva (group 2) were studied. All the isolates were tested for their ability to produce biofilm by the conventional Christensen´s method and the presence of mecA by PCR using the 22-mer oligonucleotides as primers.


RESULTS
In total 20 isolates from group 1 and 22 from group 2 were studied. Biofilm and mecA were detected in 15 (75 %) and in 14 (70 %) in group 1 as compared to 8 (36.3 %) and 4 (18.2 %) in group 2 (p = 0.016). Simultaneously, biofilm production and presence of mecA genes were observed in 13/20 (65.0 %) in group 1, and 4/22 (18.2 %) in group 2 (p = 0.002). Multi-resistance was observed in 55 % in group 1 and 9 % in group 2 (p = 0.002); 57 % of the biofilm-producing strains was multi-resistant in contrast to none of the non-producing strains. In all multi-resistant strains, biofilm production was seen.


CONCLUSIONS
Biofilm formation capacity was widely distributed, particularly among mecA (+) S. epidermidis strains, which also displayed a high diversity of antibiotic resistance profiles.
Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción, San Lorenzo, Paraguay.
Norma
N
Fariña
Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción, San Lorenzo, Paraguay. margarita.samudio@gmail.com.
Margarita
http://orcid.org/0000-0003-2813-218X
M
Samudio
Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción, San Lorenzo, Paraguay.
Letizia
L
Carpinelli
Department of Ophthalmology, Julius-Maximilians University, Würzburg, Germany.
Martin M
MM
Nentwich
Department of Ophthalmology, Ludwig-Maximilians University, Munich, Germany.
Herminia Mino
HM
de Kaspar
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D018441:Biofilms / Q000254:growth & development*; D003228:Conjunctiva / Q000382:microbiology*; D003231:Conjunctivitis / Q000188:drug therapy / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D008712:Methicillin / Q000627:therapeutic use; D016106:Methicillin Resistance; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000502:physiology*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D008712:Methicillin
Biofilm; Multiresistence; S. epidermidis; mecA gene