Mupirocin resistant staphylococcus aureus nasal colonization among healthcare workers

OUP accepted manuscript

Background

Carriers of Staphylococcus aureus among healthcare workers (HCWs) can spread the bacteria to patients and the environment, in addition to their own risk of infection.

Objectives

To determine the prevalence of S. aureus carriers among HCWs and the rate of recolonization after decolonization therapy with mupirocin.

Methods

Nasal and hand swabs from HCWs of a tertiary care hospital in Nepal were cultured on mannitol salt agar and S. aureus isolated were identified using standard microbiological procedures. Detection of MRSA and mupirocin-resistant S. aureus (MupRSA) isolates were done phenotypically. Identified S. aureus carriers were decolonized with 2% mupirocin nasal ointment. Recolonization of the carriers was assessed monthly for the next 5 months.

Results

Among the 213 HCWs, 18.3% were S. aureus carriers (35 nasal carriers, 4 both nasal and hand carriers, and no hand carriers). Overall, 9.4% of the HCWS were MRSA carriers and none were MupRSA carriers. After decolonization, 25.6% of them were recolonized and 50.0% of the recolonization was detected after 3 months of decolonization. All recolonized carriers had only MSSA strains (which colonized only nose), and none were recolonized with MupRSA.

Conclusions

HCWs are frequent carriers of S. aureus and MRSA. Due to their continuous exposure to the hospital environment, they are at risk of colonization by this MDR organism. Regular screening and decolonization of HCWs working with high risk, vulnerable patients would reduce the risk of MRSA transmission from HCWs to patients.

Mupirocin Resistance in Staphylococcus aureus Isolated from Nasal Swabs of ICU and OT Staff- A Study from A Tertiary Care Hospital

Staphylococcus aureus is one of the common causes of Healthcare-associated infection. Staphylococcus colonizes the anterior nares of the nose and tends to disseminate and secondarily colonize several other body sites including the skin and the gut. Colonized hospital personnel may be an important factor in dissemination. Staphylococcus aureus to patients and vice-versa. Mupirocin is an excellent topical anti-staphylococcal antimicrobial agent used for eradicating nasal carriage. Resistance to Mupirocin is a threat for future use of this drug in eliminating nasal carriage of Staphylococcus aureus. Thus, this study was conducted to determine the rate of Mupirocin resistance among Staphylococcus aureus isolated from nasal swabs of Health care workers (HCWs ) of Operation Theatres (OTs) and Intensive Care Units (ICUs). A single nasal swab was collected from both the anterior nares of participating health care workers of ICU and OT once at the end of their shift. Antibiotic susceptibility testing of Staphylococcus aureus to various antibiotics was done by Kirby-Bauer disk diffusion method using CLSI guidelines. High and low-level Mupirocin resistance was determined. Among 282 nasal swabs collected, Staphylococcus aureus was isolated in 62 samples. Of Staphylococcus aureus 19 came out to be Methicillin-resistant (MRSA) and the remaining 43 Methicillin sensitive (MSSA). Mupirocin resistance was seen in 3 MRSA strains and 1 MSSA strain. Thus, overall 4/62 (6.5%) strains were MupR strains. Mupirocin is the most effective antibiotic used against colonization of Staphylococcus aureus in anterior nares. Resistance to this antibiotic is thus an alarm as well as a matter of great concern. Necessary steps, policies and guidelines need to be framed to stop the spread of this resistance.