Staphylococcus aureus chlorhexidine

Use of contact lenses increases the risk of corneal infection. The most common pathogens that cause eye infection are Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, S. epidermidis, and S. pneumoniae. Fungi rarely cause eye infections. Commonly used disinfectants are benzalkonium chloride and chlorhexidine. 

Internal validity is the validity of a particular study and its claims. It is a cause-effect phenomenon. To assure internal validity, researchers are strongly advised to include a reference or control arm when evaluating a test condition. A reference arm is a treatment or condition in which the researcher has a priori knowledge of the outcome. For example, if a bacterial strain of Staphylococcus aureus, when exposed to a 4% chlorhexidine gluconate (CHG) product, is generally observed to xmdergo a 2 logio reduction in population after 30 sec... 

AR McLure, J Gordon. In-vitro evaluation of povidone-iodine and chlorhexidine against methicillin-resistant Staphylococcus aureus. J Hosp Infect 21 291-299, 1992. 

From an assessment of antibacterial activity, the resnlts show that untreated, plasma treated and acrylic-acid grafted samples did not display any antibacterial activity against strains of Escherichia coli and Staphylococcus aureus. The sample coated with triclosan met the expected antibacterial requirements and similar results were obtained for chlorhexidine-coated samples, with the average inhibition zone of 42.2 mm for Escherichia coli and 288.1 mm for Staphylococcus aureus. It is worth mentioning that both antibacterial agents are more active against Gram-positive bacteria. Finally, triclosan coated-samples showed the best results of the two antibacterial substances used. 

Ventilation-associated pneumonia continues to be a common and costly complication of critical care [13 ]. It develops after aspiration of bacteria from the oropharynx into the lung and subsequent failure of host defences to clear the bacteria. Dental plaque biofilms are colonized by respiratory pathogens in ventilated patients. Thus, improvements in oral hygiene in these patients may prevent pneumonia. In a randomized study of the minimum frequency of apphcation of chlorhexidine gluconate necessary to reduce oral colonization by pathogens in 175 intubated patients, decontamination of the oral cavity did not reduce the total amount of potential respiratory pathogens. However the chlorhexidine oral rinse did reduce the number of Staphylococcus aureus organisms in the dental... 

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