Isolates of Candida albicans that differ in virulence for mice elicit strain-specific antibody-mediated protective responses

Three distinct isolates of Candida albicans were used to establish systemic and oral infections in inbred mice that are genetically resistant or susceptible to tissue damage. Patterns of infection differed significantly between both yeasts and mouse strains. Systemic infection conferred significant protection against re-challenge with the homologous, but not the heterologous yeast; however, the protective effect was more evident in the tissue-susceptible CBA/CaH mice than in the resistant BALB/c strain. In contrast, oral infection induced protection against both homologous and heterologous oral challenge, although this was significant only in the CBA/CaH mice. CBA/CaH mice produced antibodies of both IgG1 and IgG2a subclasses, whereas BALB/c mice produced predominantly IgG1. Western blotting demonstrated considerable differences between epitopes recognised by serum antibodies from mice of both strains after immunisation with each of the three yeasts. Thus, different strains of yeast show considerable specificity in antibody responses elicited by either systemic or oral infection. (c) 2005 Elsevier SAS. All rights reserved.

Oral viral infections and the therapeutic use of antiviral agents in dentistry

This paper reviews the current concepts of viral classification, infection and replication. The clinical presentation of common oral viral infections encountered in the dental practice are discussed, including: herpes simplex virus types 1 and 2; Epstein-Barr virus; varicella-zoster virus; Coxsackie virus; human papilloma virus; and human immunodeficiency virus. The diagnosis, principles of management and pharmacological agents available for the treatment of oral viral infections are also discussed.

Canine model for investigating the impact of oral enrofloxacin on commensal coliforms and colonization with multidrug-resistant Escherichia coli

A model was developed in dogs to determine the impact of oral enrofloxacin administration on the indigenous coliform population in the gastrointestinal tract and subsequent disposition to colonization by a strain of multidrug-resistant Escherichia coli (MDREC). Dogs given a daily oral dose of 5 mg enrofloxacin kg(-1) for 21 consecutive days showed a significant decline in faecal coliforms to levels below detectable limits by 72 In of administration. Subsequently, faecal coliforms remained suppressed throughout the period of enrofloxacin dosing. Upon termination of antibiotic administration, the number of excreted faecal coliforms slowly returned over an 8-day period, to levels comparable to those seen prior to antibiotic treatment. Enrofloxacin-treated dogs were more effectively colonized by MDREC, evidenced by a significantly increased count of MDREC in the faeces (7.1 +/- 1.5 log(10) g(-1)) compared with non-antibiotic-treated dogs (5.2 +/- 1.2; P = 0.003). Furthermore, antibiotic treatment also sustained a significantly longer period of MDREC excretion in the faeces (26.8 +/- 10.5 days) compared with animals not treated with enrofloxacin (8.5 +/- 5.4 days; P = 0.0215). These results confirm the importance of sustained delivery of an antimicrobial agent to maintain and expand the colonization potential of drug-resistant bacteria in vivo, achieved in part by reducing the competing commensal coliforms in the gastrointestinal tract to below detectable levels in the faeces. Without in vivo antimicrobial selection pressure, commensal coliforms dominated the gastrointestinal tract at the expense of the MDREC population. Conceivably, the model developed could be used to test the efficacy of novel non-antibiotic strategies aimed at monitoring and controlling gastrointestinal colonization by multidrug-resistant members of the Enterobacteriaceae that cause nosocomial infections.

Oral candidosis and the therapeutic use of antifungal agents in dentistry

This paper reviews the current concepts of mycology and candidal infections as they relate to the oral cavity. Proposed classification for the presentation of oral candidosis is outlined as are examples of these topical infections, such as erythematous, pseudomembranous and hyperplastic candidosis, as well as angular chelitis and median rhomboid glossitis. The diagnosis and principles of management of oral candidosis are discussed, the therapeutic agents available for the management of these infections are presented and a treatment protocol for the management of patients with oral candidosis is given.