Deep microbial analysis of multiple placentas shows no evidence for a placental microbiome.

OBJECTIVES: To resolve the controversy regarding the presence of a microbiota in the placenta. DESIGN: Classical and molecular microbiological study. SETTING: All samples were collected during caesarean section. POPULATION: A total of 28 human placentas and six murine placentas. METHODS: All 28 human placentas were checked for 16S rRNA gene amplification products. Three locations from four selected human placentas and three 'environmental controls' for each placenta were placed in seven culture media. The four selected human placentas were further analysed using Gram stain, immunohistochemistry for bacteria, electron microscopy, and TaqMan RT-qPCR. Six placentas from three SPF mice were cut into four pieces each, and further analysed for 16S rRNA gene amplification. MAIN OUTCOME MEASURES: Microbiological and molecular evidence of bacteria. RESULTS: None of the placental cultures used for the full analysis, or their environmental cultures, was positive for bacterial growth. None of the other methods showed any evidence of bacteria. Immunohistochemistry showed negligible bacterial counts. None of the murine placentas showed evidence of 16S rRNA gene amplification. CONCLUSIONS: Our results support that the fetal environment in the womb is sterile. Based on the immunohistochemistry and the limit of detection of the other methods used, if a placental microbiome exists, it is of extreme low biomass, and thus its effect on clinical phenotypes is probably minor, if it exists at all. TWEETABLE ABSTRACT: Using several microbiological and molecular methods in parallel, we found no compelling evidence of bacteria in human and mouse placentas.

Detection and characterization of carbapenemase-producing Enterobacteriaceae in wounded Syrian patients admitted to hospitals in northern Israel.

Since 2013, four hospitals in northern Israel have been providing care for Syrian nationals, primarily those wounded in the ongoing civil war. We analyzed carbapenemase-producing Enterobacteriaceae (CPE) isolates obtained from these patients. Isolate identification was performed using the VITEK 2 system. Polymerase chain reaction (PCR) was performed for the presence of bla KPC, bla NDM, and bla OXA-48. Susceptibility testing and genotyping were performed on selected isolates. During the study period, 595 Syrian patients were hospitalized, most of them young men. Thirty-two confirmed CPE isolates were grown from cultures taken from 30 patients. All but five isolates were identified as Klebsiella pneumoniae and Escherichia coli. Nineteen isolates produced NDM and 13 produced OXA-48. Among a further 29 isolates tested, multilocus sequence typing (MLST) showed that ST278 and ST38 were the major sequence types among the NDM-producing K. pneumoniae and OXA-48-producing E. coli isolates, respectively. Most were resistant to all three carbapenems in use in Israel and to gentamicin, but susceptible to colistin and fosfomycin. The source for bacterial acquisition could not be determined; however, some patients admitted to different medical centers were found to carry the same sequence type. CPE containing bla NDM and bla OXA-48 were prevalent among Syrian wounded hospitalized patients in northern Israel. The finding of the same sequence type among patients at different medical centers implies a common, prehospital source for these patients. These findings have implications for public health throughout the region.

The physico-chemical characteristics of the phosphocholine-containing glycoglycerolipid MfGL-II govern the permeability properties of Mycoplasma fermentans.

Mycoplasma fermentans seems to be involved in several pathogenic conditions in humans, and is among other things capable of fusing with T-cells and lymphocytes. The choline-containing phosphoglycolipid 6'-O-(3"-phosphocholine-2"-amino-1"-phospho-1",3"-propanediol)-alpha-D-glucopyranosyl-(1'-->3)-1,2-diacylglycerol (MfGL-II) in the membrane of M. fermentans has been suggested to enhance the fusion process, and the characteristics of MfGL-II were therefore investigated. When a cell culture ages the fraction of MfGL-II increases, and the fraction of the other major membrane lipid, phosphatidylglycerol (PtdGro), decreases concomitantly. Swelling experiments showed that the permeability and osmotic fragility are markedly reduced in aged cells. MfGL-II is selectively released into the surrounding medium when aged M. fermentans cells are incubated in buffer containing EDTA. The physico-chemical properties of MfGL-II were studied by NMR spectroscopy and differential scanning calorimetry, and they can explain the biochemical results. The temperature for the transition between gel and lamellar liquid crystalline (Lalpha) phases is 35-45 degrees C higher for MfGL-II than for PtdGro, which most probably gives rise to the reduced permeability in aged cells. At high water contents MfGL-II forms an Lalpha phase and isotropic aggregates which were interpreted to be vesicles with a radius of approximately 450 A. It is proposed that MfGL-II forms vesicles in the surrounding medium when it is released from the cell membrane. Neither EDTA nor Ca2+ ions have a significant influence on the aggregate structures formed by MfGL-II. Our results indicate that MfGL-II has no fusogenic properties. It is more probable that a recently identified lysolipid in the M. fermentans membrane acts as a fusogen.