Survival of Fecal Contamination Indicator Organisms in Soil

Soils amended with human or animal waste may result in pathogen contamination of ground and surface water. Because temperature has been shown to affect pathogen survival, two laboratory studies were conducted to evaluate the impact of extremes in temperature on bacterial and viral pathogen indicator die-off in soil. A Captina silt loam was amended with broiler litter (0.1 g/g dry soil), septic tank effluent, or Escherichia coli (ATCC 13706) culture (both at 0.04 and 0.1 mL/g dry soil in the two respective studies), incubated at 5 and 35°C, and analyzed over time to determine the number of fecal coliform, E. coli, and coliphage remaining. Pathogen indicator die-off rate constants (k) for all indicator- temperature-treatment combinations were determined by first-order kinetics. For all three pathogen indicators, die-off was significantly more rapid at 35°C than at 5°C. In both studies, fecal coliform die-off rates were not different from E. coli die-off rates across each temperature-treatment combination. Levels of these bacterial indicators appeared in a ratio of 1:0.94 with 95% confidence intervals at 0.89 and 0.99 in the E. coli- and litter-amended soils. Die-off of the viral indicator was significantly slower than the die-off of the bacterial indicators at 5°C in litter-amended soil. Die-off of the bacterial indicator, E. coli, in soil amended with E. coli culture was not significantly different than die-off in soil amended with broiler litter at 5 or 35°C in the two studies. Because the higher incubation temperature increased die-off rates for all three indicators, it is expected that the potential for contamination of ground and surface water decreases with increasing temperature

Completion Report: Arkansas State Pesticides in Ground Water Monitoring Project Phase V: Vulnerable areas in Jackson, Monroe, Lawrence and Lonoke Counties

In 1996, sixty-seven water samples were drawn from 65 wells, including 62 new wells and 3 wells sampled previously . One Woodruff County well and two Pulaski County wells were resampled. Thirty-two samples were drawn from 30 wells in Monroe County (well #1 was sampled 3 times during this phase) . Ten wells in Jackson County, 12 wells in Lawrence County and 10 wells in Lonoke were also tested (Figures 1-5) . With the completion of Phase V, the number of wells tested has risen to 231 with a total of 258 samples analyzed . Initially, the wells were tested for 13 pesticides and ni~rate. Two more pesticides, aldicarb and carbofuran were added to the analyte list during Phase V. The analyte list is shown in Table 3 . All results from all the wells are listed in Appendix A. Quality control information for these data follow the results. The Phase V Quality Assurance Report is included in this document as Part II

Extended-spectrum beta-lactamases-producing <i>Escherichia coli</i> in common vampire bats <i>Desmodus rotundus</i> and livestock in Peru

Antibiotic resistance mediated by bacterial production of extended‐spectrum beta‐lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital‐acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL‐producing bacteria. Only limited data are available on the circulation of ESBL‐producing bacteria in animals. Here, we report ESBL‐producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of blaCTX‐M‐15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resistance that were not always host species‐specific, suggesting sharing of strains between species or infection from a common source. This study shows widespread ESBL resistance in wild and domestic animals, supporting animal communities as a potential source of resistance. Future work is needed to elucidate the role of bats in the dissemination of antibiotic‐resistant strains of public health importance and to understand the origin of the observed resistance

Bowman's layer dystrophy with irido-fundal coloboma in the same patient: a case report

Introduction: The corneal dystrophies are rare corneal diseases, defined as bilateral, symmetric and inherited conditions. Ocular coloboma is a congenital defect caused by embryogenesis imperfection, during the sixth week of development. Purpose: The authors report the first clinical case in literature of the association of cornea dystrophy and irido-fundal coloboma. Case report: The authors describe the case of a 34-year-old woman, with decrease visual acuity (VA) in the right and left eyes (RLE). She has had an ocular illness since young, with corneal erosions. Her family members also have alterations in the cornea, her father has held a bilateral corneal transplant. Ophthalmic examination showed a best-corrected visual acuity (BCVA) of 20/40 in the RE and 20/100 in the LE. Biomicroscopy showed an inferior iris coloboma in the LE. A deposition of reticular/granular substance in the Bowman’s layer was observed in both eyes, sparing the limbal portion, compatible with a corneal dystrophy. Fundus examination showed a coloboma in the LE that involves the inferior retina and the optic nerve, no changes in the RE fundus was observed. She started treatment with ocular lubrificant preservative-free eyedrops. The patient has remained stable within 1-year follow-up. Conclusions: This is the first case report of the association of cornea dystrophy and irido-fundal coloboma. The greater decrease in VA in the LE appears to be due to the combination of these two entities in this eye. Despite the Bowman’s layer dystrophy has an autosomal dominant pattern, coloboma seems to have been an acquired change.info:eu-repo/semantics/publishedVersio

Quantum mechanical path integrals and thermal radiation in static curved spacetimes

The propagator of a spinless particle is calculated from the quantum mechanical path integral formalism in static curved spacetimes endowed with event-horizons. A toy model, the Gui spacetime, and the 2D and 4D Schwarzschild black holes are considered. The role of the topology of the coordinates configuration space is emphasised in this framework. To cover entirely the above spacetimes with a single set of coordinates, tortoise coordinates are extended to complex values. It is shown that the homotopic properties of the complex tortoise configuration space imply the thermal behaviour of the propagator in these spacetimes. The propagator is calculated when end points are located in identical or distinct spacetime regions separated by one or several event-horizons. Quantum evolution through the event-horizons is shown to be unitary in the fifth variable.Comment: 22 pages, 10 figure

Thermal radiation in non-static curved spacetimes: quantum mechanical path integrals and configuration space topology

A quantum mechanical path integral derivation is given of a thermal propagator in non-static Gui spacetime. The thermal nature of the propagator is understood in terms of homotopically non-trivial paths in the configuration space appropriate to tortoise coordinates. The connection to thermal emission from collapsing black holes is discussed.Comment: 20 pages, major revised version, 9 figures, new titl