A three-year surveillance of nosocomial infections by methicillin-resistant Staphylococcus haemolyticus in newborns reveals the disinfectant as a possible reservoir.
OBJECTIVE
Study of the clonality of methicillin-resistant Staphylococcus haemolyticus responsible of epidemic infections in a neonatal intensive care unit.


METHODS
Methicillin-resistant Staphylococcus haemolyticus isolates were collected during the period from March 2004 to November 2006, from newborns, the clean hands of nurses and from disinfectant bottles used in the unit. Molecular typing by pulsed-field gel electrophoresis (PFGE) was achieved for all isolates.


RESULTS
Forty-six isolates of S. haemolyticus resistant to methicillin were collected from 42 newborns, the hand of two nurses and from two disinfectant bottles used in the unit. PFGE analysis revealed five types (A, B, C, D and E) among newborns isolates. Types A and B were predominant. Nurses' isolates revealed PFGE types similar to types A and B. Disinfectant isolates were of type B. qacA/B PCR analysis revealed that the majority of type B isolates contain the disinfectant resistance gene qacA/B. No isolate of type A possessed this gene.


CONCLUSIONS
These results suggest that MRSH neonatal infections are caused by a limited number of clones. Clone B was able to survive in disinfectant bottles and to conserve its ability to infect newborns. We therefore conclude that the disinfectant can serve as a reservoir for MRSH and point out the need to control all disinfectants used in a neonatal intensive care unit.
Ben Saida
N
N
Laboratoire de microbiologie-immunologie (UR 02-SP13), CHU Farhat Hached, Avenue Ibn Jazzar, 4001 Sousse, Tunisia.
Marzouk
M
M
Ferjeni
A
A
Boukadida
J
J
D002404:Catheterization / Q000592:standards; D002555:Cerebrospinal Fluid / Q000382:microbiology; D017931:DNA Primers; D004197:Disease Reservoirs; D004202:Disinfectants / Q000009:adverse effects* / Q000592:standards; D016521:Electrophoresis, Gel, Pulsed-Field; D005784:Gene Amplification; D006225:Hand / Q000382:microbiology; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000592:standards; D016106:Methicillin Resistance / Q000235:genetics*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D017283:Neonatal Nursing / Q000592:standards; D009741:Nursing Staff, Hospital / Q000592:standards; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000209:etiology
D017931:DNA Primers; D004202:Disinfectants