Orange County Public Health Laboratory

Santa Ana, CA, United States

Orange County Public Health Laboratory

Santa Ana, CA, United States
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Hellberg R.S.,Chapman University | Li F.,Ibis Biosciences | Sampath R.,Ibis Biosciences | Yasuda I.J.,Ibis Biosciences | And 6 more authors.
Food Microbiology | Year: 2014

The goal of this study was to develop an assay for the detection and differentiation of noroviruses using RT-PCR followed by electrospray ionization mass spectrometry (ESI-MS). Detection of hepatitis A virus was also considered. Thirteen primer pairs were designed for use in this assay and a reference database was created using GenBank sequences and reference norovirus samples. The assay was tested for inclusivity and exclusivity using 160 clinical norovirus samples, 3 samples of hepatitis A virus and 3 other closely related viral strains. Results showed that the assay was able to detect norovirus with a sensitivity of 92% and a specificity of 100%. Norovirus identification at the genogroup level was correct for 98% of samples detected by the assay and for 75% of a subset of samples (n=32) compared at the genotype level. Identification of norovirus genotypes is expected to improve as more reference samples are added to the database. The assay was also capable of detecting and genotyping hepatitis A virus in all 3 samples tested. Overall, the assay developed here allows for detection and differentiation of noroviruses within one working day and may be used as a tool in surveillance efforts or outbreak investigations. © 2014 Elsevier Ltd.


Respicio-Kingry L.B.,Centers for Disease Control and Prevention | Byrd L.,Dermatology Clinic | Allison A.,Dermatology Clinic | Brett M.,Centers for Disease Control and Prevention | And 5 more authors.
Journal of Clinical Microbiology | Year: 2013

A 69-year-old patient presented with a tender, thickly crusted skin lesion of 1 week's duration. A bacterial culture swab taken from the underlying granular tissue yielded a pure isolate of a Gram-negative coccobacillus, presumptively identified as a novel Francisella species via 16S rRNA and multilocus gene sequence analysis. Copyright © 2013, American Society for Microbiology.


PubMed | Southern California Coastal Water Research Project, Orange County Public Health Laboratory, California State University, Long Beach, University of California at Los Angeles and Virginia Polytechnic Institute and State University
Type: Journal Article | Journal: FEMS microbiology ecology | Year: 2016

Enterococci are fecal indicator bacteria used to monitor fecal pollution of recreational waters. When enterococci levels exceed health standards, fecal pollution is assumed as the cause. Enterococci growing on plants limit their usefulness as fecal indicator bacteria. Here we examined enterococcal growth on eelgrass in Mission Bay, CA where enterococci levels have exceeded water quality thresholds. A total of 69 eelgrass samples were collected from six sites, shaken to remove enterococci attached to plant surfaces and the eluant filtered onto culture media. Isolates were then identified to species using biochemical methods, and DNA typing by pulsed-field gel electrophoresis was done to assess clonality of strains. Enterococci concentrations among eelgrass ranged from 8 to 14000 CFUg(-1) dry weight. The most predominant enterococcal species found were Enterococcus casseliflavus and E. hirae followed by E. faecalis. Cluster analysis indicated a high level of clonality among isolates across all species, with clonal isolates consistently associated with individual eelgrass samples. Finding high densities of E. casseliflavus, E. hirae and E. faecalis on eelgrass that included clonal strains indicates the capability of enterococcal growth on eelgrass. Amplification of enterococci on eelgrass presents challenges for regulatory agencies that interpret elevated levels of these bacteria as an indication of fecal pollution.


Rippy M.A.,University of California at San Diego | Franks P.J.S.,University of California at San Diego | Feddersen F.,University of California at San Diego | Guza R.T.,University of California at San Diego | Moore D.F.,Orange County Public Health Laboratory
Marine Pollution Bulletin | Year: 2013

A suite of physical-biological models was used to explore the importance of mortality and fluid dynamics in controlling concentrations of fecal indicator bacteria (FIB) at Huntington Beach, CA. An advection-diffusion (AD) model provided a baseline to assess improvements in model skill with the inclusion of mortality. Six forms of mortality were modeled. All mortality models performed better than the AD model, especially at offshore sampling stations, where model skill increased from <0.18 to >0.50 (Escherichia coli) or <-0.14 to >0.30 (Enterococcus). Models including cross-shore variable mortality rates reproduced FIB decay accurately (p< 0.05) at more stations than models without. This finding is consistent with analyses that revealed cross-shore variability in Enterococcus species composition and solar dose response. No best model was identified for Enterococcus, as all models including cross-shore variable mortality performed similarly. The best model for E. coli included solar-dependent and cross-shore variable mortality. © 2012 Elsevier Ltd.


Rippy M.A.,University of California at San Diego | Franks P.J.S.,University of California at San Diego | Feddersen F.,University of California at San Diego | Guza R.T.,University of California at San Diego | Moore D.F.,Orange County Public Health Laboratory
Marine Pollution Bulletin | Year: 2013

We present results from a 5-h field program (HB06) that took place at California's Huntington State Beach. We assessed the importance of physical dynamics in controlling fecal indicator bacteria (FIB) concentrations during HB06 using an individual based model including alongshore advection and cross-shore variable horizontal diffusion. The model was parameterized with physical (waves and currents) and bacterial (Escherichia coli and Enterococcus) observations made during HB06. The model captured surfzone FIB dynamics well (average surfzone model skill: 0.84 {. E. coli} and 0.52 {. Enterococcus}), but fell short of capturing offshore FIB dynamics. Our analyses support the hypothesis that surfzone FIB variability during HB06 was a consequence of southward advection and diffusion of a patch of FIB originating north of the study area. Offshore FIB may have originated from a different, southern, source. Mortality may account for some of the offshore variability not explained by the physical model. © 2012 Elsevier Ltd.

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