Margaret S. Terpenning

Methicillin-resistant Staphylococcus aureus: Colonization and Infection in a Long-term Care Facility

OBJECTIVE To assess methicillin-resistant Staphylococcus aureus (MRSA) colonization, transmission, and infection over a 1-year period in a long-term care facility with endemic MRSA. DESIGN Monthly surveillance for MRSA colonization of nares, perineum, rectum, and wounds. SETTING Long-term care facility attached to an acute care Veterans Affairs medical center. PATIENTS All 341 patients in the facility had monthly surveillance cultures for 1 year. OUTCOME MEASUREMENTS Colonization and infection with MRSA. MAIN RESULTS The monthly MRSA colonization rate was 23% +/- 1.0%; colonization occurred most commonly in the nares and wounds. Poor functional status was associated with MRSA colonization. Most patients (65%) never acquired MRSA; 25% of patients were already colonized at admission to the facility or at the start of the study, and only 10% of newly admitted patients acquired MRSA while in the facility. These latter patients acquired several different strains in a pattern of acquisition similar to that generally seen within the facility. In the course of 1 year, only nine patients who acquired MRSA had a roommate with the same phage type; no clustering was evident, and none of these patients developed infection. Nine other patients (3%) developed MRSA infection; five of these patients required hospitalization, but none died as a result of infection. CONCLUSIONS In the long-term care facility in which our study took place, MRSA was endemic, and the infection rate was low. In such settings, the cost effectiveness of aggressive management of MRSA (widespread screening for MRSA and eradication with antimicrobial agents) needs to be assessed.

Aspiration Pneumonia: Dental and Oral Risk Factors in an Older Veteran Population

OBJECTIVES: To investigate the importance of medical and dental factors in aspiration pneumonia in an older veteran population.

Attempts to eradicate methicillin-resistant Staphylococcus aureus from a long-term-care facility with the use of mupirocin ointment

PURPOSE To assess the impact of the use of mupirocin ointment on colonization, transmission, and infection with methicillin-resistant Staphylococcus aureus (MRSA) in a long-term-care facility. PATIENTS AND METHODS All 321 residents of a Veterans Affairs long-term-care facility from June 1990 through June 1991 were studied for MRSA colonization and infection. MRSA-colonized patients received mupirocin ointment to nares in the first 7 months and to nares and wounds in the second 5 months. The effect of mupirocin use on MRSA colonization and infection was monitored. All S. aureus strains isolated were tested for the development of resistance to mupirocin. RESULTS A total of 65 patients colonized with MRSA received mupirocin ointment. Mupirocin rapidly eliminated MRSA at the sites treated in most patients by the end of 1 week. Weekly maintenance mupirocin was not adequate to prevent recurrences--40% of patients had recurrence of MRSA. Overall, MRSA colonization in the facility, which was 22.7% +/- 1% prior to the use of mupirocin, did not change when mupirocin was used in nares only (22.2% +/- 2.1%), but did decrease to 11.5% +/- 1.8% when mupirocin was used in nares and wounds. Although colonization decreased, roommate-to-roommate transmission and MRSA infection rates, low to begin with, did not change when mupirocin was used. Mupirocin-resistant MRSA strains were isolated in 10.8% of patients. CONCLUSIONS Mupirocin ointment is effective at decreasing colonization with MRSA. However, constant surveillance was required to identify patients colonized at admission or experiencing recurrence of MRSA during maintenance treatment. Long-term use of mupirocin selected for mupirocin-resistant MRSA strains. Mupirocin should be saved for use in outbreak situations, and not used over the long term in facilities with endemic MRSA colonization.

Xerostomia, Xerogenic Medications and Food Avoidances in Selected Geriatric Groups

OBJECTIVE: To study the relationship between complaints of xerostomia and salivary performance and food avoidances in four geriatric groups chosen to reflect a broad spectrum of individuals along the health‐disease continuum. To determine whether xerogenic medications taken by these individuals could be associated with either complaints of xerostomia or with food avoidances.

Colonization and Infection with Antibiotic‐Resistant Bacteria in a Long‐Term Care Facility

OBJECTIVE: To assess colonization and infection with methicillin‐resistant Staphylococcus aureus (MRSA), high‐level gentamicin‐resistant enterococci (R‐ENT) and gentamicin and/or ceftriaxone‐resistant Gram‐negative bacilli (R‐GNB) and the factors that are associated with colonization and infection with these organisms.

Increasing resistance of Staphylococcus aureus to ciprofloxacin.

We demonstrated the marked emergence of resistance to ciprofloxacin among Staphylococcus arueus strains isolated at the Ann Arbor Veterans Administration Medical Center. All S. aureus isolates tested from 1984 to 1985 were susceptible, whereas 55.1% of methicillin-resistant and 2.5% of methicillin-susceptible strains from 1989 had high-level resistance to ciprofloxacin.

Geriatric Oral Health and Pneumonia Risk

The oral cavity is a complex microenvironment consisting of multiple bacterial and fungal species, their associated biofilms, and a cytokine milieu influenced by constant inflammatory stimulation. Multiple infectious consequences of poor oral health have been extensively described and primarily affect older adults. Probably the most common sequelae of poor oral health in aged persons is a risk of aspiration pneumonia. The risk of aspiration pneumonia is greatest when periodontal disease, dental caries, and poor oral hygiene are compounded by swallowing disease, feeding problems, and poor functional status. The effectiveness of oral hygiene interventions for preventing aspiration pneumonia and barriers to oral care of nursing home patients require additional study, but the current state of research in these areas is reviewed in this manuscript. The expense of aspiration pneumonia as a nursing home complication makes dental hygiene a potentially cost-saving intervention.

Staphylococcus aureus nasal colonization in a nursing home: eradication with mupirocin.

Recent reports have emphasized an increase in both infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) in institutionalized older patients. We studied whether or not local treatment with mupirocin ointment could eliminate nasal colonization with S aureus. A total of 102 patients in a Veterans Administration nursing home were screened for S aureus nasal colonization. Thirty-nine patients (38.2%) were colonized, 18 with methicillin-sensitive Saureus (MSSA) and 21 with MRSA. Almost half of all colonized patients were in the most dependent functional category and there was a significant association of MRSA colonization, but not MSSA colonization, with poor functional status. Colonized patients were treated with mupirocin ointment applied to the anterior nares twice daily for seven days. After treatment, MSSA persisted in only two patients and MRSA in only one patient; thus, nasal colonization was eliminated in 91.4% of colonized patients. At one month and two months follow-up, 11 patients became transiently recolonized and three became persistently recolonized with S aureus. Mupirocin was well tolerated with no side effects noted. Mupirocin ointment may be useful in controlling nasal colonization with S aureus in the nursing home setting.

Increasing resistance of enterococci to ciprofloxacin.

We determined that resistance to ciprofloxacin has emerged in enterococci over the last 5 years in our hospital, mainly in strains demonstrating the phenotype of high-level gentamicin resistance. All high-level-gentamicin-resistant isolates from 1985 and 1986 were susceptible, whereas 24% of isolates from 1989 and 1990 were resistant to ciprofloxacin. Plasmid and genomic DNA typing showed at least six unique strains exhibiting resistance, but one type accounted for 80% of recent resistant isolates, suggesting a role for cross infection in the emergence of resistance.

Detection and characterization of mupirocin resistance in Staphylococcus aureus.

Fourteen mupirocin-resistant Staphylococcus aureus strains were isolated over 18 months; 12 exhibited low-level resistance, while two showed high-level resistance. Highly mupirocin-resistant strains contained a large plasmid which transferred mupirocin resistance to other S. aureus strains and to Staphylococcus epidermidis. This plasmid and pAM899-1, a self-transferable gentamicin resistance plasmid, have molecular and biologic similarities. Images