The Role of MRSA (Methicillin-Resistant <i>Staphylococcus aureus</i>) Adherence and Colonization in the Upper Respiratory Tract of Geriatric Patients in Nosocomial Pulmonary Infections
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- Rikitomi Naoto
- Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
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- Nagatake Tsuyoshi
- Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
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- Sakamoto Tasuku
- Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
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- Matsumoto Keizo
- Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University
Bibliographic Information
- Other Title
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- The Role of MRSA (Methicillin‐Resistant <i>Staphylococcus aureus</i>) Adherence and Colonization in the Upper Respiratory Tract of Geriatric Patients in Nosocomial Pulmonary Infections
Abstract
The mechanism of nosocomial respiratory infections caused by MRSA (methicillin-resistant Staphylococcus aureus) in geriatric patients was investigated. Seriously ill patients (SIP) undergoing naso-gastric tube feeding or intravenous hyperalimentation and moderately ill patients (MIP) who were orally fed, were examined for their colonization and infection by Staphylococcus aureus (S. aureus) in the respiratory tract. Colonization of MRSA in the upper respiratory tract in SIP was from six to ten times higher than that in MIP and was associated with a high incidence of MRSA pulmonary infections. In vitro S. aureus adherence to nasal or oropharyngeal cells demonstrated that bacteria binding to nasal cells was higher, which probably can be interpreted as an elevated occurrence of S. aureus colonization in the nasal cavity than in the throat. The binding activity of MRSA was not superior to that of MSSA (methicillin-sensitive S. aureus). Though MRSA binding to the nasal cells from SIP was not higher than those from MIP, MRSA colonization in the upper respiratory tract was more frequently seen in SIP (P<0.01). A higher incidence of total infectious episodes (P<0.02-0.001) and more frequent use of antibiotics (P <0.02-0.001), which were potent against MSSA might be the basis for selection of MRSA in these patients. In fact, the rate of MRSA colonization on the skin (pressure sores) was also higher in SIP (P<0.01). A low nutritional state in SIP (P<0.01-0.02) might also be associated with MRSA colonization. The present results indicate that the high frequency of infections, antibiotic administration, MRSA skin colonization and low nutritional condition, are enhancing factors of MRSA acquisition in the respiratory tract for SIP undergoing artificial feeding, in a geriatric hospital.
Journal
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- MICROBIOLOGY and IMMUNOLOGY
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MICROBIOLOGY and IMMUNOLOGY 38 (8), 607-614, 1994
Center For Academic Publications Japan
