Oral Polymyxin Research Articles

What's trending in the infection prevention and control literature? From HIS 2012 to HIS 2014, and beyond

SummaryThis is an informal review of some of the trends in the infection prevention and control literature since the last Healthcare Infection Society (HIS) conference in late 2012. Google Trends was used to investigate how the volume of interest in various infection control topics had changed over time. Ebola trumped all the others in Google searches, reflecting a surge of publications in the literature. Aside from Ebola, other trends in the infection prevention and control literature covered in this article include Middle East Respiratory Syndrome (MERS) coronavirus, universal versus targeted interventions, faecal microbiota transplantation, whole genome sequencing, carbapenem-resistant Enterobacteriaceae, and some aspects of environmental science. The review ends with an attempt to predict some of the trends in the infection prevention and control literature between now and the next HIS conference in 2016.

A randomized double-blind clinical trial of the effect of non-absorbable oral polymyxin on infants with severe infectious diarrhea

The present study evaluated the effect of non-absorbable oral polymyxin on the duodenal microflora and clinical outcome of infants with severe infectious diarrhea. Polymyxin was chosen because classic enteropathogenic Escherichia coli was more sensitive to this antibiotic. Twenty-five infants were randomly assigned to a 7-day treatment with oral polymyxin (2.5 mg/kg in 4 daily doses) or placebo. Duodenal and stool cultures were performed before and after the treatment. Five patients were excluded during the study because of introduction of parental antibiotic therapy due to clinical sepsis (N = 3) or rapid clinical improvement (N = 2). In the polymyxin group, small bowel bacterial overgrowth occurred in 61.5% of the cases (8/13) before treatment and in 76.9% (10/13) after treatment. In the placebo group these values were 71.4% (5/7) and 57.1% (4/7), respectively. By the 7th day, clinical cure was observed in 84.6% of the cases (11/13) in the polymyxin group and in 71.4% (5/7) in the placebo group (P = 0.587). Considering all 25 patients included in the study, clinical cure occurred on the 7th day in 12/14 cases (85.7%) in the polymyxin group and 6/11 cases (54.5%) in the placebo group (P = 0.102). Clinical sepsis occurred in 3/11 (27.3%) of the patients in the placebo group and in none (0/14) in the polymyxin group (P = 0.071). Oral polymyxin was not effective in reducing bacterial overgrowth or in improving the clinical outcome of infants hospitalized with severe infectious diarrhea. Taking into account the small sample size, the rate of cure on the 7th day and the rate of clinical sepsis, further studies with greater number of patients are necessary to evaluate these questions.

A randomized double-blind clinical trial of the effect of non-absorbable oral polymyxin on infants with severe infectious diarrhea

The present study evaluated the effect of non-absorbable oral polymyxin on the duodenal microflora and clinical outcome of infants with severe infectious diarrhea. Polymyxin was chosen because classic enteropathogenic Escherichia coli was more sensitive to this antibiotic. Twenty-five infants were randomly assigned to a 7-day treatment with oral polymyxin (2.5 mg/kg in 4 daily doses) or placebo. Duodenal and stool cultures were performed before and after the treatment. Five patients were excluded during the study because of introduction of parental antibiotic therapy due to clinical sepsis (N = 3) or rapid clinical improvement (N = 2). In the polymyxin group, small bowel bacterial overgrowth occurred in 61.5% of the cases (8/13) before treatment and in 76.9% (10/13) after treatment. In the placebo group these values were 71.4% (5/7) and 57.1% (4/7), respectively. By the 7th day, clinical cure was observed in 84.6% of the cases (11/13) in the polymyxin group and in 71.4% (5/7) in the placebo group (P = 0.587). Considering all 25 patients included in the study, clinical cure occurred on the 7th day in 12/14 cases (85.7%) in the polymyxin group and 6/11 cases (54.5%) in the placebo group (P = 0.102). Clinical sepsis occurred in 3/11 (27.3%) of the patients in the placebo group and in none (0/14) in the polymyxin group (P = 0.071). Oral polymyxin was not effective in reducing bacterial overgrowth or in improving the clinical outcome of infants hospitalized with severe infectious diarrhea. Taking into account the small sample size, the rate of cure on the 7th day and the rate of clinical sepsis, further studies with greater number of patients are necessary to evaluate these questions.

Bacterial translocation induces remnant liver injury after subtotal (90%) hepatectomy in rats —The effect of decontamination of gram-negative rods in digestive tract by oral polymyxin B treatment—

Bacterial translocation induces remnant liver injury after subtotal (90%) hepatectomy in rats &mdash;<I>The effect of decontamination of gram-negative rods in digestive tract by oral polymyxin B treatment</I>&mdash;

Selective intestinal decontamination for prevention of wound colonization in severely burned patients: a retrospective analysis

In this study the effect of selective intestinal decontamination of the digestive tract (SDD) on wound colonization was investigated. Ninety-one patients with at least 25 per cent total burned surface area (TBSA) were included in this study. All patients received oral polymyxin. In 63 patients oral co-trimoxazole and amphotericin B were added to the regimen. The addition of co-trimoxazole decreased the incidence of Enterobacteriaceae wound colonization from 71 per cent to 11 per cent ( P<0.005). Colonization with Proteus was eliminated in patients treated with co-trimoxazole, compared with an incidence of 36 per cent in the group treated with polymyxin alone ( P < 0.001). The addition of amphotericin B decreased yeast colonization of the burn wound from 39 per cent to 10 per cent ( P < 0.005). A, close relation was observed between burn wound colonization and colonization of the gastrointestinal tract. No resistant bacterial strains emerged during the period of study. These results suggest that SDD is an effective method for prevention of wound colonization. Further controlled studies are needed to establish the role of SDD in preventing burn wound colonization and wound sepsis.

Polymyxin B reduces cecal flora, TNF production and hepatic steatosis during total parenteral nutrition in the rat

Hepatic complications are common in patients receiving total parental nutrition (TPN) and who have no underlying liver disease. In the present study we examined the hypothesis that endotoxin (LPS) or possibly TNF derived from the overgrowth of intestinal gram-negative bacteria is responsible for TPN-associated hepatic steatosis, and that bowel decontamination and specific anti-LPS activity of polymyxin B will reduce fatty infiltration of the liver during TPN. Forty-five male Sabra rats underwent jugular vein cannulation, were placed in metabolic cages, and were randomized into five groups. Group I was continuously infused with normal saline and allowed food ad lib, while group II–V were continuously infused with a TPN formula containing 4.25% amino acids and 25% dextrose for a total of 36 calories and 3.0 g protein per 100 g body weight/day. In addition, groups III–IV were also treated by oral polymyxin B while Groups IV and V received a combination of neomycin, metronidazole, and vancomycin (NMV). Thus, Group III received polymyxin B, Group IV received both polymyxin B and NMV, while Group V received NMV only. On Days 7–8 of the study, all animals were sacrificed and spontaneous production of TNF by peritoneal macrophages, bacterial translocation to mesenteric lymph nodes, culture of the cecum, and fat, triglyceride, and cholesterol contents of the liver were determined. All groups infused with TPN exhibited higher levels of total fat, triglycerides, and cholesterol compared to the free feeding control group ( P < 0.001). Both groups receiving oral polymyxin exhibited a significant reduction in total liver fat ( P < 0.02) and triglyceride ( P < 0.001) levels compared to rats receiving TPN or TPN + NMV. The amount of gram-negative bacteria in the cecum of TPN-treated rats (Group II) was significantly higher than found in the free feeding rats (Group I). All antibiotic-treated groups had significantly lower gram-negative CFU than both the TPN and control groups due to bowel decontamination either by polymyxin B, NMV, or both. Simultaneously, spontaneous production of TNF by peritoneal macrophages of TPN-treated rats was significantly higher compared to control rats ( P < 0.005) or those who received TPN with antimicrobial therapy ( P < 0.03-0.005). In the present study both groups receiving polymyxin B exhibited reduced bacterial counts, reduced TNF production by peritoneal macrophages, representing the splanchnic reticuloendothelial system, and lower total fat and triglyceride levels in the livers of TPN rats. As the detrimental effects of LPS and the production of TNF in response to lipopolysaccaride were shown to be blocked by polymyxin B, this could well explain the protection afforded by polymyxin B against lipopolysaccharide-induced hepatic toxicity and steatosis, in addition to its very effective antibacterial activity in the gut, as demonstrated by the reduced gram-negative bacterial counts in the cecum of polymyxin B-treated rats.

Enterobacteriaceae suppression by three different oral doses of polymyxin E in human volunteers

Polymyxin E is frequently used as an oral drug for flora suppression of the gastrointestinal canal. The suppression effect is dose dependent because polymyxin E is moderately inactivated by faecal and food compounds. Three oral polymyxin E doses (150, 300, 600 mg daily) were given to six volunteers for 6 days. The Enterobacteriaceae suppression effect was compared by means of the suppression index i.e. ratio of total number of faecal samples free of Enterobacteriaceae to the total number of faecal samples. The impact on the indigenous (mostly anaerobic) flora was measured in four ways: (i) beta-aspartylglycine content; (ii) volatile fatty acid pattern; (iii) yeast overgrowth and (iv) Streptococcus faecalis decrease. Enterobacteriaceae suppression was most successful during 600 mg oral polymyxin E (suppression indices during 150, 300 and 600 mg were 0.32, 0.55 and 0.89 respectively). None of the four markers of indigenous flora alterations were positive. However, using this dosage half of the volunteers suffered rather severe gastrointestinal side-effects. Oral polymyxin E in a dosage of minimum 600 mg daily seems to possess the ideal properties of a flora suppression agent, if the gastrointestinal side-effects could be mitigated.

Effect of intestinal flora modulation by oral polymyxin treatment on hemopoietic stem cell kinetics in mice.

After oral treatment with polymyxin for only 1 day, fecal aerobic gram-negative bacteria were found completely suppressed in C3H/Law mice. Complete suppression of aerobic gram-negative bacteria was accompanied by a reduction of the fecal endotoxin concentration from 100 to 10 micrograms endotoxin per gram of feces as measured with the Limulus amebocyte lysate assay. Oral administration of polymyxin affected hemopoietic stem cell kinetics at different stages. The kinetic behavior of hemopoietic stem cells was determined as the in vivo sensitivity to the S phase specific cytostatic drug hydroxyurea. The hydroxyurea kill of bone marrow spleen colony-forming cells diminished not significantly (p less than 0.10) from 14 to 4% after 2 days of polymyxin treatment. Already after 1 day of treatment the hydroxyurea kill of bone marrow progenitor cells forming granulocyte-macrophage colonies in vitro decreased from 29 to 7% (p less than 0.05). It took 8 days of treatment before the hydroxyurea kill of splenic granulocyte-macrophage colonies was found reduced from 53 to 14% (p less than 0.001). The decreased susceptibility of hemopoietic stem cells to hydroxyurea during polymyxin treatment appears to argue for a role of intestinal aerobic gram-negative bacteria in the regulation of hemopoiesis, probably mediated by endotoxin.

Absolute barrier isolation and antibiotics in the treatment of experimental burn wound sepsis

1. 1. A model for studying the effect of absolute barrier isolation on mortality from burn wound sepsis is described. 2. 2. Systemic polymyxin alone did not increase survival in this model. 3. 3. Topical mafenide with or without systemic polymyxin markedly improved survival from experimental burn wound sepsis. 4. 4. The mortality of animals treated with systemic and oral polymyxin, topical mafenide, and absolute barrier (germfree) isolation was the same as the mortality of similarly treated animals without isolation. 5. 5. In this model, absolute barrier isolation was of no value in the treatment of experimentally contaminated burn wounds.

Treatment of chronic shigella infections in children with oral polymyxin

Treatment of chronic shigella infections in children with oral polymyxin