The value of Bacteroidales genetic markers and fecal indicator bacteria (FIB) to predict the occurrence of waterborne pathogens was evaluated in ambient waters along the central California coast. Bacteroidales host-specific quantitative PCR (qPCR) was used to quantify fecal bacteria in water and provide insights into contributing host fecal sources. Over 140 surface water samples from 10 major rivers and estuaries within the Monterey Bay region were tested over 14 months with four Bacteroidales-specific assays (universal, human, dog, and cow), three FIB (total coliforms, fecal coliforms, and enterococci), two protozoal pathogens (Cryptosporidium and Giardia spp.), and four bacterial pathogens (Campylobacter spp., Escherichia coli O157:H7, Salmonella spp., and Vibrio spp.). Indicator and pathogen distribution was widespread, and detection was not highly seasonal. Vibrio cholerae was detected most frequently, followed by Giardia, Cryptosporidium, Salmonella, and Campylobacter spp. Bayesian conditional probability analysis was used to characterize the Bacteroidales performance assays, and the ratios of concentrations determined using host-specific and universal assays were used to show that fecal contamination from human sources was more common than livestock or dog sources in coastal study sites. Correlations were seen between some, but not all, indicator-pathogen combinations. The ability to predict pathogen occurrence in relation to indicator threshold cutoff levels was evaluated using a weighted measure that showed the universal Bacteroidales genetic marker to have a comparable or higher mean predictive potential than standard FIB. This predictive ability, in addition to the Bacteroidales assays providing information on contributing host fecal sources, supports using Bacteroidales assays in water quality monitoring programs.

Caution should be exercised when using human-based immunoassays for the diagnosis of Giardia and Cryptosporidium spp. in cats. Fecal flotation remains a useful method for detection of Giardia spp., can be used to detect other parasites, and has a sensitivity of 97.8% for detection of Giardia spp. when combined with the SNAP Giardia immunoassay.

Recent studies have suggested a potential role for wild birds in zoonotic transmission of Campylobacter jejuni, the leading cause of gastroenteritis in humans worldwide. In this study, we detected Campylobacter spp. in 66.9% (85/127) of free-ranging American crows (Corvus brachyrhyncos) sampled in the Sacramento Valley of California in 2012 and 2013. Biochemical testing and sequence analysis of 16S rRNA revealed that 93% of isolates (n ‫؍‬ 70) were C. jejuni, with cytolethal distending toxin (CDT) and flagellin A genes detected by PCR in 20% and 46% of the C. jejuni isolates (n ‫؍‬ 59), respectively. The high prevalence of C. jejuni, coupled with the occurrence of known virulence markers CDT and flagellin A, demonstrates that crows shed Campylobacter spp. in their feces that are potentially pathogenic to humans. Crows are abundant in urban, suburban, and agricultural settings, and thus further study to determine their role in zoonotic transmission of Campylobacter will inform public health.

b s t r a c tThe Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis) is a migratory game bird of North America that is at risk for population decline. Epidemics of avian trichomonosis caused by upper digestive tract infection with Trichomonas spp. protozoa in these and other doves and pigeons of the United States are sporadic, but can involve tens of thousands of birds in a single event. Herein, we analyze the role of trichomonosis in band-tailed pigeon mortality and relate spatial, temporal and demographic patterns of parasite transmission to the genetic background of the infecting organism. Infections were most common in adult birds and prevalence was high in band-tailed pigeons sampled at mortality events (96%) and rehabilitation centers (36%) compared to those that were hunter-killed (11%) or live-caught (4%). During non-epidemic periods, animals were primarily infected with T. gallinae Fe-hydrogenase subtype A2, and were less often infected with either T. gallinae subtype A1 (the British finch epidemic strain), T. stableri n. sp. (a T. vaginalis-like species), or Tritrichomonas blagburni n. sp.-like organisms. Birds sampled during multiple epidemics in California were only infected with T. gallinae subtype A2 and T. stableri. The non-clonal etiology of avian trichomonosis outbreaks in band-tailed pigeons and the risk of spill-over to raptor and passerine species highlights the need for additional studies that clarify the host range and evolutionary relationships between strains of Trichomonas spp. in regions of trichomonosis endemicity.

Clostridium difficile-associated-diarrhea (CDAD) is a nosocomial infection in dogs. Diagnosis of this infection is dependent on clinical signs of disease supported by laboratory detection of C. difficile toxins A or B, or both, in fecal specimens via enzyme-linked immunosorbent assay (ELISA). Unfortunately, to the authors' knowledge, commercially available ELISAs have not been validated in dogs to date. We evaluated 5 ELISAs done on 143 canine fecal specimens (100 diarrheic and 43 nondiarrheic dogs) and on 29 C. difficile isolates. The results of each ELISA were compared with the cytotoxin B tissue culture assay (CTA). Clostridium difficile was isolated from 23% of the fecal specimens. Eighteen of the 143 fecal specimens were toxin positive (15 diarrheic and 3 nondiarrheic dogs). On the basis of multiplex polymerase chain reaction (PCR) analysis for toxin-A and -B genes, 72% of the isolates were toxigenic. The carriage rate of toxigenic isolates in diarrheic dogs was higher than that in the nondiarrheic dogs; however, these differences were not statistically significant. A good correlation was found between CTA, PCR, and culture results. The ELISAs done on fecal specimens collected from diarrheic dogs had low sensitivity (7-33%). In contrast, ELISA for toxin A or B, or both, performed on toxigenic isolates had high sensitivity (93%). These results suggest that commercially available human ELISAs are inadequate for the diagnosis of canine C. difficile-associated diarrhea when tested on fecal specimens. In contrast, the Premier ToxinA/B and Techlab ToxinA/B ELISAs may be useful for the diagnosis of canine CDAD when used on toxigenic isolates.

This study supports the use of synovial fluid as a biological matrix for studying the effects of corticosteroids on gene expression. For the majority of genes studied the effects on expression relative to baseline for both inflammatory and matrix genes were prolonged relative to plasma and synovial fluid TA concentrations. Downregulation of collagen gene expression warrants the careful use of TA in horses.

Marine mammals are at risk for infection by fecal-associated zoonotic pathogens when they swim and feed in polluted nearshore marine waters. Because of their tendency to consume 25-30% of their body weight per day in coastal filter-feeding invertebrates, southern sea otters (Enhydra lutris nereis) can act as sentinels of marine ecosystem health in California. Feces from domestic and wildlife species were tested to determine prevalence, potential virulence, and diversity of selected opportunistic enteric bacterial pathogens in the Monterey Bay region. We hypothesized that if sea otters are sentinels of coastal health, and fecal pollution flows from land to sea, then sea otters and terrestrial animals might share the same enteric bacterial species and strains. Twenty-eight percent of fecal samples tested during 2007-2010 were positive for one or more potential pathogens. Campylobacter spp. were isolated most frequently, with an overall prevalence of 11%, followed by Vibrio cholerae (9%), Salmonella spp. (6%), V. parahaemolyticus (5%), and V. alginolyticus (3%). Sea otters were found positive for all target bacteria, exhibiting similar prevalences for Campylobacter and Salmonella spp. but greater prevalences for Vibrio spp. when compared to terrestrial animals. Fifteen Salmonella serotypes were detected, 11 of which were isolated from opossums. This is the first report of sea otter infection by S. enterica Heidelberg, a serotype also associated with human clinical disease. Similar strains of S. enterica Typhimurium were identified in otters, opossums, and gulls, suggesting the possibility of land-sea transfer of enteric bacterial pathogens from terrestrial sources to sea otters.

Potentially zoonotic enteric pathogens were identified in samples from several species admitted to wildlife hospitals, indicating potential for transmission if prevention is not practiced.