Douglas H. Sprunt

A Study of Moniliasis in Aureomycin Therapy

Summary (1) In vitro sensitivity studies established a definite inhibitory effect by methyl and propyl paraben (para-hydroxy-benzoic acid) on 5 strains of yeast. (2) Methyl and propyl paraben are essentially non-toxic when administered orally, vaginally or rectally. (3) Methyl and propyl paraben are of value in preventing the overgrowth of C. albicans associated with aureomycin therapy.

THE GROUND SUBSTANCE IN INFECTION

After an infectious agent has passed the epithelial barrier, the ground substance plays a large part in determining whether it is disseminated or localized. The first point to be considered in regard to the ground substance in infection is whether the spread of an infectious agent in the ground substance is beneficial to the host or to the infectious agent. The second point is whether the reverse is true. I n other words, does localization of the infectious agent favor the host or the infectious agent? Before proceeding further, we shall define some of the terms used in this paper, for their use is not always the same. “Infection,” the first of these terms, is the ability of the infecting agent to multiply and cause disease in the host. The second is “ground substance,” a term used to define the tissue beneath the epithelium. This tissue, which is of a gel-like consistency, is composed largely of polymers of hyaluronic acid. The third term, “virulence,” is the ability of a small number of infectious organisms to cause disease. I t is now a well-accepted fact in bacteriology that a certain number of a given organism are needed to infect an experimental animal or to cause growth in artificial media. About twenty-five years ago, when experimentation in this field was active, this phenomenon was referred to as the “colonial effect.’’ This term was used because it was pointed out that the conditions of survival for an inoculum of bacteria on artificial media or in an experimental animal were analogous to those encountered by colonists in it new land. For example, i f the colonists were tau few i n number, or were not adapted by previous training to the hardships of colonial life, the colony would not survive; but if the group was larger or better adapted, there would be some survivors to form a nucleus of a successful colony. Likewise, if the number of bacteria were too small, or if the bacteria were not adapted (virulent) to the host or the artificial media, a small number would not survive where larger or better adapted (more virulent) ones would. To phrase this differently, there is a definite relationship between the quantity of an infectious agent and the volume of material in which it is grown For each infectious agent, there is a critical ratio of infectious agent to volume of material below which the infectious agent cannot survive. The concentration of an infectious agent in the tissues of the host is, of course, dependent on whether i t can easily spread through the tissues or whether it is localized at the point of entry. The survival or death of the infectious agent is dependent on the concentration of the infectious agent per volume of tissue. In other words, the colonial effect applies here in much the same way as it does to the growth of bacteria in artificial media or their survival in the experimental animal as a whole. Duran-Reynals‘ first stated the principle that the spread of itn infectious agent or agents may favor, a t times, the host, and, a t other times, the

A study of hemolytic streptococcal infections in relation to antistreptolysin O titer changes in orphanage children

Summary Observations are reported on a one-yearorphanage study of hemolytic streptococcal infections, during which weekly throat cultures and monthly antistreptolysin O determinations were made. When these data were analyzed in relation to clinical and subclinical illness in the study group and the influence of limited specific therapy, the following observations were made: 1. The high prevalence of infectionwith hemolytic streptococci during the early months of the study was considered to represent a convalescent carrier state, due to the low prevalence of clinical illness and the downward trend of antistreptolysin O titers. 2. During this early period, widespreadinfection with Group C hemolytic streptococci was encountered, without associated clinical illness or significant increases in antistreptolysin O titer. However, the latter occurred during the subsequent months of the study in nine children following infection with this organism. The potential significance of Group C infections, in relation to rheumatic fever, is discussed. 3. Clinical illness and significant increasesin antistreptolysin O titer were noted most frequently in the youngest age group and less frequently in the older age groups of the study, following the acquisition of Group A hemolytic streptococci. 4. Significant increases in antistreptolysin O titer were preceded most frequently by upper respiratory illness in the youngest age group and less frequently in the older age groups, in whom subclinical infections were more common. 5. Nontypable Group A hemolyticstreptococci encountered during our study appeared to be as capable of producing clinical illness and immunologic responses as typable organisms. 6. Failure of prophylactic penicillinproducing adequate blood levels (0.03 to 0.125 unit per milliliter) to eradicate Group C hemolytic streptococci was observed in a few instances. While tetracycline hydrochloride achieved the eradication of these organisms, its administration was followed by the emergence of large numbers of staphylococci. The latter produced no adverse effects even during an epidemic of measles. 7. The failure of short courses of penicillin and tetracycline antibiotics to eradicate hemolytic streptococci was repeatedly observed, and the implications of this, and of the observations made above, in the prevention of rheumatic fever are discussed.

Increased susceptibility of mice to swine influenza as a result of methionine injections.

Conclusions Mice on a low protein diet, if given methionine, have a greatly increased susceptibility to the swine influenza virus.