Nasal carriage of Staphylococcus aureus and cross-contamination in a surgical intensive care unit: efficacy of mupirocin ointment

Abstract

A six month prospective study was carried out in a surgical intensive care unit (SICU) of a university hospital to assess the incidence and routes of exogenous colonization by Staphylococcus aureus. A total of 157 patients were included in the study. One thousand one hundred and eleven specimens (nasal, surgical wound swabs, tracheal secretions obtained on admission and once a week thereafter, and all clinical specimens) were collected over a four month period from patients without nasal decontamination (A). They were compared with 729 specimens collected over a two month period from patients treated with nasal mupirocin ointment (B). All S. aureus strains were typed by restriction fragment length polymorphism (RFLP) pulsed-field gel electrophoresis after SmaI macrorestriction. The nasal colonization rates on admission were 25.5 and 32.7% in groups A and B, respectively. Thirty-one untreated patients (31.3%) and three patients (5.1%) treated with nasal ointment, acquired the nasal S. aureuS in the SICU (P=O.O0027). Nasal carriers were more frequently colonized in the bronchopulmonary tract (Bp) and surgical wound (SW) (62%) than patients who were not nasal carriers (14%) (P<O.OOOOl). The patterns were identical for nasal, Bp and SW strains from the same patient. RFLP analysis characterized seven epidemic strains of methicillin-resistant S. aureus (MRSA) which colonized 60% of group A and 9% of group B patients (P<O.OOOOl). The bronchopulmonary tract infection rate was reduced in group B (P= 0.032). In conclusion, in an SICU, nasal carriage of S. aureus appeared to be the source of endogenous and cross-colonization. The use of nasal mupirocin ointment reduced the incidence of Bp and SW colonization, as well as the MRSA infection rate.

Enterocolitis Caused by Methicillin‐Resistant Staphylococcus aureus: Molecular Characterization of Respiratory and Digestive Tract Isolates

“…Moreover, treatment with nasal mupirocin ointment is effective in reducing the surgical site, bronchopulmonary tract infection (20) and postoperative infection with S. aureus (26). The latter treatment was recently adopted as a control measure against MRS A infections (3, 5).…”

Infection control of Staphylococcus aureus : spa typing to elucidate transmission

“…Eradication of nasal carriage has proven effective in the reduction of endogenous infections (Talon et al 1995;Kluytmans et al 1996a;Kluytmans et al 1996b). Infections caused by strains other than the one detected in the nares of the patient self, have been suggested to originate from HCWs and/or fellow patients (Perl et al 2002).…”

Low Concentrations of Mupirocin in the Pharynx following Intranasal Application May Contribute to Mupirocin Resistance in Methicillin-Resistant Staphylococcus aureus

“…Mupirocin is the most effective antibiotic for elimination of MRSA from the nasal passages (6). Moreover, intranasal application of mupirocin ointment is effective in reducing surgical-site infections and the likelihood of bronchopulmonary tract infection (5,15). However, cases of mupirocin-resistant MRSA have already been reported (11).…”