Probiotics versus antibiotic decontamination of the digestive tract: infection and mortality

Purpose: Selective decontamination of the digestive tract (SDD) has been shown to decrease the infection rate and mortality in intensive care units (ICUs); Lactobacillus plantarum 299/299v plus fibre (LAB) has been used for infection prevention and does not harbour the potential disadvantages of antibiotics. The objective was to assess whether LAB is not inferior to SDD in infection prevention. Methods: Two hundred fifty-four consecutive ICU patients with expected mechanical ventilation ≥48 h and/or expected ICU stay ≥72 h were assigned to receive SDD: four times daily an oral paste (polymyxin E

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats in the south of Brazil: a molecular study

Bartonella spp are the causative agent of cat scratch disease in humans. Cats are the natural reservoir of these bacteria and may infect humans through scratches, bites or fleas. Blood samples from 47 cats aged up to 12 months were collected for this study. All animals were lodged in municipal animal shelters in the Vale do Sinos region, Rio Grande do Sul, Brazil. Bartonella spp were detected by genus-specific polymerase chain reaction (PCR) and when the PCR was positive, the species were determined by DNA sequencing. A Giemsa-stained blood smear was also examined for the presence of intraerythrocytic elements suggestive of Bartonella spp infection. Phylogenetic analysis was also performed for all positive samples. Using molecular detection methods, Bartonella spp were detected in 17.02% (8/47) of the samples. In seven out of eight samples confirmed to be positive for Bartonella spp, blood smear examination revealed the presence of intraerythrocytic elements suggestive of Bartonella spp. Phylogenetic analysis characterized positive samples as Bartonella henselae (5) or Bartonella clarridgeiae (3). To the best of our knowledge, this is the first molecular study demonstrating the presence of Bartonella spp in cats from the Southern Region of Brazil

Impact of digestive and oropharyngeal decontamination on the intestinal microbiota in ICU patients

Selective digestive microbial decontamination (SDD) is hypothesized to benefit patients in intensive care (ICU) by suppressing Gram-negative potential pathogens from the colon without affecting the anaerobic intestinal microbiota. The purpose of this study was to provide more insight to the effects of digestive tract and oropharyngeal decontamination on the intestinal microbiota by means of a prospective clinical trial in which faecal samples were collected from ICU patients for intestinal microbiota analysis. The faecal samples were collected from ICU patients enrolled in a multicentre trial to study the outcome of SDD and selective oral decontamination (SOD) in comparison with standard care (SC). Fluorescent in situ hybridization (FISH) was used to analyze the faecal microbiota. The numbers of bacteria from different bacterial groups were compared between the three regimens. The total counts of bacteria per gram faeces did not differ between regimens. The F. prausnitzii group of bacteria, representing an important group among intestinal microbiota, was significantly reduced in the SDD regimen compared to the SC and SOD. The Enterobacteriaceae were significantly suppressed during SDD compared to both SOD and SC; enterococci increased in SDD compared to both other regimens. The composition of the intestinal microbiota is importantly affected by SDD. The F. prausnitzii group was significantly suppressed during SDD. This group of microbiota is a predominant producer of butyrate, the main energy source for colonocytes. Reduction of this microbiota is an important trade-off while reducing gram-negative bacteria by SDD

Changes in Human Fecal Microbiota Due to Chemotherapy Analyzed by TaqMan-PCR, 454 Sequencing and PCR-DGGE Fingerprinting

BACKGROUND: We investigated whether chemotherapy with the presence or absence of antibiotics against different kinds of cancer changed the gastrointestinal microbiota. METHODOLOGY/PRINCIPAL FINDINGS: Feces of 17 ambulant patients receiving chemotherapy with or without concomitant antibiotics were analyzed before and after the chemotherapy cycle at four time points in comparison to 17 gender-, age- and lifestyle-matched healthy controls. We targeted 16S rRNA genes of all bacteria, Bacteroides, bifidobacteria, Clostridium cluster IV and XIVa as well as C. difficile with TaqMan qPCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting and high-throughput sequencing. After a significant drop in the abundance of microbiota (p = 0.037) following a single treatment the microbiota recovered within a few days. The chemotherapeutical treatment marginally affected the Bacteroides while the Clostridium cluster IV and XIVa were significantly more sensitive to chemotherapy and antibiotic treatment. DGGE fingerprinting showed decreased diversity of Clostridium cluster IV and XIVa in response to chemotherapy with cluster IV diversity being particularly affected by antibiotics. The occurrence of C. difficile in three out of seventeen subjects was accompanied by a decrease in the genera Bifidobacterium, Lactobacillus, Veillonella and Faecalibacterium prausnitzii. Enterococcus faecium increased following chemotherapy. CONCLUSIONS/SIGNIFICANCE: Despite high individual variations, these results suggest that the observed changes in the human gut microbiota may favor colonization with C. difficile and Enterococcus faecium. Perturbed microbiota may be a target for specific mitigation with safe pre- and probiotics