Application): The presence of bacterial indicators of biological water quality is commonly determined by the use of culturing techniques. However, indicator bacteria can not always grow on artificial media due to injury or stress imposed by prevailing environmental conditions. Consequently, culturing methods often underestimate the in situ densities of indicator bacteria. It is therefore necessary to use methods that do not exclusively rely on microbial growth in artificial media to accurately determine microbial densities. The proposed work deals with the development of nucleic acid based methods to determine the presence and survival of enteric bacteria in tropical recreational waters. One method will use fluorescently labeled rRNA targeting probes in whole cell hybridization studies. Initial studies will evaluate the sensitivity of this assay using eubacterial rDNA probes against bacterial indicators of fecal contamination (e.g., Escherichia coli, Enterococcus faecalis). A specific effort will be focused on developing a resuscitation approach to increase the sensitivity of the probing method. The rDNA probing technology will then be used to determine survival rates of E. coli in recreational waters using membrane diffusion chambers. An alternate molecular approach to monitor bacterial cells will consist of the development of an in situ PCR technique. This method will use rRNA and mRNA transcripts as targets and therefore it will be specific for active cells. A epifluorescence microscope linked to a charge coupled device and image analysis software will be used to further increase the sensitivity of both whole cell hybridization and in situ PCR assays and to decrease errors due to cell autofluorescence and background noise (i.e., fluorescing debris). This approach will also provide a quantitative estimation of the different levels of activity of enteric microorganisms, including pathogenic bacteria, in complex environmental samples. This information is essential to better estimate the risks associated with the presence of pathogens in tropical recreational waters.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Minority Biomedical Research Support - MBRS (S06)
Project #
2S06GM008102-29
Application #
6358616
Study Section
Minority Programs Review Committee (MPRC)
Project Start
1988-06-01
Project End
2004-06-30
Budget Start
Budget End
Support Year
29
Fiscal Year
2000
Total Cost
$110,273
Indirect Cost
Name
University of Puerto Rico Rio Piedras
Department
Type
DUNS #
City
San Juan
State
PR
Country
United States
Zip Code
00931
Ramírez-Camejo, Luis A; Maldonado-Morales, Génesis; Bayman, Paul (2017) Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens? Int J Microbiol 2017:8526385
Morales-Rivera, Keyla F; Piñero Cruz, Dalice M; Prieto, Jose A (2017) Crystal structure of (-)-(S)-4-[(2S,3S,4S,Z)-3-hydroxy-4-methyl-hept-5-en-2-yl]-1,3-dioxolan-2-one. Acta Crystallogr E Crystallogr Commun 73:1070-1072
García-Arriaga, Marilyn; Acosta-Santiago, Maxier; Cruz, Antony et al. (2017) Probing the Limits of Supramolecular G-Quadruplexes Using Atomistic Molecular Dynamics Simulations. Inorganica Chim Acta 468:209-222
Huang, Qing; Quiñones, Edwin (2016) A spectroscopic method to determine the activity of the restriction endonuclease EcoRV that involves a single reaction. Anal Biochem 497:103-5
Mège, Pascal; Schizas, Nikolaos V; Reyes, Joselyd García et al. (2015) Genetic seascape of the threatened Caribbean elkhorn coral, Acropora palmata, on the Puerto Rico Shelf. Mar Ecol (Berl) 36:195-209
Morales-Rivera, Amarilys; Hernández-Burgos, Mayté M; Martínez-Rivera, Arlene et al. (2014) Anxiolytic effects of oxytocin in cue-induced cocaine seeking behavior in rats. Psychopharmacology (Berl) 231:4145-55
Ramírez-Camejo, Luis A; Torres-Ocampo, Ana P; Agosto-Rivera, José L et al. (2014) An opportunistic human pathogen on the fly: strains of Aspergillus flavus vary in virulence in Drosophila melanogaster. Med Mycol 52:211-9
Galindo-Cardona, Alberto; Acevedo-Gonzalez, Jenny P; Rivera-Marchand, Bert et al. (2013) Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico. BMC Genet 14:65
Santiago-Rodriguez, Tasha M; Rivera, Jessica I; Coradin, Mariel et al. (2013) Antibiotic-resistance and virulence genes in Enterococcus isolated from tropical recreational waters. J Water Health 11:387-96
Pantoja-Feliciano, Ida Gisela; Clemente, Jose C; Costello, Elizabeth K et al. (2013) Biphasic assembly of the murine intestinal microbiota during early development. ISME J 7:1112-5

Showing the most recent 10 out of 194 publications