Occurrence and patterns of antibiotic resistance in vertebrates off the Northeastern United States coast

Abstract

The prevalence of antibiotic-resistant bacteria in the marine environment is a growing concern, but the degree to which marine mammals, seabirds and fish harbor these organisms is not well documented. This project sought to identify the occurrence and patterns of antibiotic resistance in bacteria isolated from vertebrates of coastal waters in the northeastern United States. 472 isolates of clinical interest were tested for resistance to a suite of 16 antibiotics. Fifty-eight percent were resistant to at least one antibiotic, while 43% were resistant to multiple antibiotics. A multiple antibiotic resistance (MAR) index value greater than or equal to 0.2 was observed in 38% of the resistant pathogens, suggesting exposure of the animals to bacteria from significantly contaminated sites. Groups of antibiotics were identified for which bacterial resistance commonly co-occurred. Antibiotic resistance was more widespread in bacteria isolated from seabirds than marine mammals, and was more widespread in stranded or bycaught marine mammals than live marine mammals. Structuring of resistance patterns based on sample type (live/stranded/bycaught) but not animal group (mammal/bird/fish) was observed. These data indicate that antibiotic resistance is widespread in marine vertebrates, and they may be important reservoirs of antibiotic resistant bacteria in the marine environment.

Antibiotic-Resistant Escherichia coli Bacteria, Including Strains with Genes Encoding the Extended-Spectrum Beta-Lactamase and QnrS, in Waterbirds on the Baltic Sea Coast of Poland

“…Studies of resistant E. coli isolates have been mostly based on phenotype characterization of these isolates (20, 24, 26, 51, 58, 71,75,76,82), and the genes determining resistance to oldgeneration antibiotics were sporadically detected (17,21,22,29). Isolates of E. coli from birds on the Polish coast of the Baltic Sea were commonly resistant to old-generation antibiotics, and they were highly variable in phenotype and genotype characteristics.…”

“…In particular, bird populations sympatric to areas inhabited by people and areas with a high density of livestock were colonized with antibiotic-resistant E. coli strains possibly selected by the antibiotic practice in humans and domestic animals. Antibiotic-resistant E. coli isolates have been found in corvids (Corvus corone, C. frugilegus, C. macrorhynchos, Pica pica, and Pyrrhocorax pyrrhocorax) (3,46,48,53,74), house sparrows (Passer domesticus) (22,61), house martins (Delichon urbica) (73), feral pigeons (Columba livia forma domestica) (68), ducks, geese, and swans (Anas platyrhynchos, Anas acuta, Branta canadensis, and Cygnus columbianus) (17,26,51,82), cormorants (Phalacrocorax auritus and P. cristatus) (20,71), Egyptian vultures (Neophron percnopterus) (2), and, most frequently, in various gull species throughout the world (Larus argentatus, L. atricilla, L. audouinii, L. cachinans, L. crassirostris, L. glaucoides, L. hyperboreus, L. marinus, L. ridibundus, and L. vagae) (4,7,21,23,29,66,71,76,82). Corvids and gulls feeding on garbage dumps and in urbanized areas are frequently colonized with resistant strains of E. coli, and they are considered to be important reservoirs and vectors of these isolates in the environment (23,46).…”

MOLECULAR DETECTION OF ANTIBIOTIC-RESISTANCE DETERMINANTS INESCHERICHIA COLIISOLATED FROM THE ENDANGERED AUSTRALIAN SEA LION (NEOPHOCA CINEREA)

“…In particular, antibiotic-resistant bacteria are becoming more common in marine wildlife populations (Stoddard et al 2008;Rose et al 2009), indicating colonization by terrestrial bacteria or integration of antibioticresistance determinants in the microbiota of wildlife species. The mobility of DNA elements encoding antibiotic resistance has been instrumental in the rapid spread of antibiotic resistance, both in a clinical setting and in naturally occurring ecosystems (Partridge et al 2009).…”

“…Culture-based screening and antibiotic sensitivity testing have identified resistance to greater than 10 antibiotics across six seal species (e.g., Lockwood et al 2006;Rose et al 2009). However, these techniques are unable to identify specific resistance determinants and their origins, and this knowledge gap limits understanding of dispersal of antibiotic resistance in wild marine populations (Stokes et al 2001).…”

Dynamics of Vibrio with Virulence Genes Detected in Pacific Harbor Seals (Phoca vitulina richardii) Off California: Implications for Marine Mammal Health

“…Current knowledge of the diversity and ecology of marine pathogens in harbor seals is limited to clinical cases, serological surveys, zoonotic cases (marine mammal caretakers), and epidemics associated with animal-stranding events [10,37,38,73,78,83,92]. The most common cause of live harbor seal strandings in central California during the last ten years was malnutrition (52%) [16].…”