Effect of streptomycin administration on colonization resistance to Salmonella typhimurium in mice

Abstract

The addition of 5 mg of streptomycin sulfate per ml to the drinking water of Swiss white mice resulted in a 100,000-fold reduction in the 50% implantation dose of streptomycin-resistant Salmonella typhimurium for the animals. When streptomycin-treated and untreated mice were challenged orogastrically with 103 viable S. typhimurium organisms, 100% of the treated and none of the untreated mice excreted the pathogen in their feces. Similarly, translocation of S. typhimurium from the intestinal tract to the liver, spleen, and mesentery occurred in 10 of 10 treated mice but in none of the untreated mice 7 days after challenge with 103 CFU. Studies of colonization dynamics showed that S. typhimurium was present at high population levels in the intestines of streptomycin-treated mice and in detectable levels in the liver, spleen, and mesentery within 72 h after challenge with 103, 105, or 108 organisms. In untreated mice challenged with either 103 or 105 S. typhimurium organisms, the organisms were isolated from ileal and cecal tissues but not from ileal or cecal contents or from extraintestinal tissue 72 h after challenge. When untreated mice were challenged with 108 organisms, however, S. typhimurium was present in all organs and in intestinal contents. Streptomycin treatment, therefore, facilitated colonization and development of streptomycin-resistant S. typhimurium populations in intestines of mice and the subsequent translocation of the organisms from the intestinal tract to other tissues.

Increased Antibody Production against Gut‐Colonizing Escherichia coli in the Presence of the Anaerobic Bacterium Peptostreptococcus

“…Thus, mice or guinea pigs who do not harbour an indigenous anaerobic bacterial flora are much more vulnerable, e.g. to Shigella, Vibrio cholerae or Salmonella infection, than are normal animals [29,30]. In addition to a direct suppressive effect on the population level of pathogens or potential pathogens, a stimulation of the immune system by the anaerobic bacteria may be of importance for this protection.…”

Conjugal transfer of aminoglycoside and macrolide resistance between Enterococcus faecium isolates in the intestine of streptomycin-treated mice

“…In vivo transfer experiments were carried out in the intestine of streptomycin-treated mice as previously described by Hentges and co-workers [22][23][24]. The recipient was allowed to establish in the intestine for 5 days before the donor strain was inoculated.…”

“…Six female NMRI mice (20 AE 2 g) (Taconic M&B, Ry, Denmark), caged two by two, with an intact normal flora were treated with 5000 mg l À1 streptomycin sulphate in the drinking water according to Hentges and co-workers [22][23][24]. After 24 h, fecal samples were taken, homogenized in 0.9% (w/v) NaCl and plated on Bile Aesculin Azide agar plates (Difco, Detroit, USA) with either 10 mg l À1 erythromycin, 25 mg l À1 fusidic acid, 25 mg l À1 rifampin or 10 mg l À1 erythromycin or Table 1 Primerlist…”

Acute colonization study of polychlorinated biphenyl‐degrading pseudomonads in the mouse intestinal tract: Comparison of single and multiple exposures

“…The colonization resistance of the mouse (3.1. tract has been studied using other microbes as well. Streptomycin treatment enhanced Salmonella typhimurium intestinal colonization and translocation to other organs [25]. Volatile fatty acids were one of the factors responsible for decreased colonization in untreated animals [25].…”