Risk Factors for Infection with Pathogenic and Antimicrobial-Resistant Fecal Bacteria in Northern Elephant Seals in California

Abstract

SYNOPSISObjectives. The goal of this study was to identify potential environmental and demographic factors associated with Campylobacter jejuni (C. jejuni), Salmonella enterica (Salmonella spp.), and antimicrobial-resistant Escherichia coli (E. coli) infection in northern elephant seals stranded along the California coastline.Methods. E. coli, Salmonella spp., and C. jejuni were isolated from rectal swabs from 196 juvenile northern elephant seals, which were found stranded and alive along the California coast and brought to The Marine Mammal Center in Sausalito, California, for rehabilitation. Gender, weight, county where the animal stranded, month stranded, coastal human population density, exposure to sewage outfall or freshwater outflow (river or stream), and cumulative precipitation in the previous 24 hours, seven days, 30 days, 90 days, and 180 days were analyzed as potential risk factors for infection.Results. The odds of C. jejuni and antimicrobial-resistant E. coli were higher in feces of seals stranded at sites with higher levels of freshwater outflow compared with lower levels of freshwater outflow. The odds of Salmonella spp. in feces were 5.4 times greater in seals stranded in locations with lower levels of 30-day cumulative precipitation, along with substantially lower odds of Salmonella shedding for seals stranded in Monterey or Santa Cruz county compared with seals stranded in regions further north or south of this central California location.Conclusions. Juvenile northern elephant seals that have entered the water are being colonized by antimicrobial-resistant and pathogenic fecal bacteria that may be acquired from terrestrial sources transmitted via river and surface waters.

Surveillance for zoonotic and selected pathogens in harbor seals Phoca vitulina from central California

“…In this study, seal exposure was associated with small boat harbors. While the Campylobacterpositive seals were not associated with known outfalls and sewage discharges, a more in-depth analysis of the variable flow rates at the discharge locations might be necessary to detect an association, as was done in a study of northern elephant seal Mirounga angustirostris infection (Stoddard et al 2008).…”

“…In this study, seal exposure was associated with small boat harbors. While the Campylobacterpositive seals were not associated with known outfalls and sewage discharges, a more in-depth analysis of the variable flow rates at the discharge locations might be necessary to detect an association, as was done in a study of northern elephant seal Mirounga angustirostris infection (Stoddard et al 2008).The prevalence of Salmonella in stranded harbor seals (1%) was much lower than that reported in stranded northern elephant seals M. angustirostris from the same region (36.9%, Stoddard et al 2005) although Newport, the most common serotype among the stranded elephant seals, was detected in a harbor seal. Among stranded seals in the United Kingdom, grey seals Halichoerus grypus also had a greater prevalence of Salmonella than harbor seals (Baker et al 1995).…”

ENTERIC PATHOGENS AND ANTIMICROBIAL RESISTANCE IN TURKEY VULTURES (CATHARTES AURA) FEEDING AT THE WILDLIFE–LIVESTOCK INTERFACE

“…Cultures for the target bacteria were performed using selective enrichment and media, 14 with Salmonella serotyping performed at the National Veterinary Services Laboratory (National Veterinary Services Laboratory, USDA-APHIS-VS-NVSL, Ames, Iowa 50010, USA). Antimicrobial susceptibilities for E. coli and Salmonella enterica isolates were determined using broth microdilution 14 with standard panels (COMEQ3F and COMPAN1F Veterinary Plates, Trek Diagnostic Systems, Inc., Cleveland, Ohio 44131, USA). Prevalence of antimicrobial resistance and multidrug resistance patterns were determined for vultures and sheep sampled for this study.…”

Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface

“…Freshwater runoff and particle transport are also directly influenced by storm patterns and the quantity, duration, intensity, and frequency of precipitation in the watershed [150,151]. Infections and deaths in marine mammals due to terrestrially derived fecal protozoa and bacteria have been temporally and spatially linked to increased precipitation or land-based runoff [152,153]. …”