Responsiveness of experimental surgical-wound infections to topical chemotherapy

Impetigo Animal Models: A Review of Their Feasibility and Clinical Utility for Therapeutic Appraisal of Investigational Drug Candidates

Impetigo (school sores), a superficial skin infection commonly seen in children, is caused by the gram-positive bacteria Staphylococcus aureus and/or Streptococcus pyogenes. Antibiotic treatments, often topical, are used as the first-line therapy for impetigo. The efficacy of potential new antimicrobial compounds is first tested in in vitro studies and, if effective, followed by in vivo studies using animal models and/or humans. Animal models are critical means for investigating potential therapeutics and characterizing their safety profile prior to human trials. Although several reviews of animal models for skin infections have been published, there is a lack of a comprehensive review of animal models simulating impetigo for the selection of therapeutic drug candidates. This review critically examines the existing animal models for impetigo and their feasibility for testing the in vivo efficacy of topical treatments for impetigo and other superficial bacterial skin infections.

Methods of quantitative microbiological analyses that support the diagnosis, treatment, and prognosis of human infection

The microorganisms responsible for the production of an infection may be considered to be in two classes: classical microbes and host-defined microbes. Classical microbes are those pathogens which fulfill the Koch-Henle postulates, and their isolation from a host indicates infection. They are not normally part of the body's normal flora, although they may be acquired by the host and enter into a passive relationship known as the carrier state. Examples of this type of microbe are Bacillus anthracis (anthrax), Yersinia pestis (plague), and Bordetella pertussis (whooping cough). Pathogens that require specific hosts have largely replaced the classical pathogen as a cause of infection in hospitalized patients. Especially in recent years, with the advent of new modes of anticancer treatment and the general ability of the medical community to extent a patient's life span by chemotherapy and innovative surgery, the contribution to morbidity and mortality by microbes has substantially increased. These host-specific pathogens are largely part of the body's normal flora. It is incumbent upon the clinical microbiologist to be able to distinguish the patient's normal microbial load, an increased load due to physiological factors, but not representing infection, and a significant change from normal which should be considered infection. The ability to distinguish infection from noninfection is one of the prime responsibilities of the clinical microbiology laboratory and has contributed to the development of the infectious disease subspecialty of internal medicine. This article will examine a critical question: Is there a relationship between the numbers of microorganisms isolated from a specimen and the production of infection, and, if so, does this relationship vary for the different anatomical sites of the body?

Structure of chelocardin, a novel tetracycline antibiotic

Reproducible experimental surgical-wound infections in mice for use in the evaluation of topical antibacterial agents are described. The experimental would was created on the backs of mice by means of a midline incision and was infected by means of cotton sutures monocontaminated with Staphylococcus aureus or Pseudomonas aeruginosa. The course of these wound infections was followed by quantitation of surface bacteria through use of a surface rinse technique. Surface wound counts of the infecting organisms thus obtained appeared to reflect the dynamics of the total wound count, as determined by homogenization of biopsied tissue. Treatment of infected wounds with a placebo cream had only a slight effect on surface wound counts and on mortality in the case of the S. aureus infection but enhanced markedly the lethality of the P. aeruginosa infection.