Migratory Wild Birds as a Potential Disseminator of Antimicrobial-Resistant Bacteria around Al-Asfar Lake, Eastern Saudi Arabia

Abstract

Migratory wild birds acquire antimicrobial-resistant (AMR) bacteria from contaminated habitats and then act as reservoirs and potential spreaders of resistant elements through migration. However, the role of migratory wild birds as antimicrobial disseminators in the Arabian Peninsula desert, which represents a transit point for birds migrating all over Asia, Africa, and Europe not yet clear. Therefore, the present study objective was to determine antimicrobial-resistant bacteria in samples collected from migratory wild birds around Al-Asfar Lake, located in Al-Ahsa Oasis, Eastern Saudi Arabia, with a particular focus on <i>Escherichia coli</i> virulence and resistance genes. Cloacal swabs were collected from 210 migratory wild birds represent four species around Al-Asfar. <i>E. coli</i>, <i>Staphylococcus</i>, and <i>Salmonella</i> spp. have been recovered from 90 (42.9%), 37 (17.6%), and 5 (2.4%) birds, respectively. Out of them, 19 (14.4%) were a mixed infection. All samples were subjected to AMR phenotypic characterization, and results revealed (14-41%) and (16-54%) of <i>E. coli</i> and <i>Staphylococcus</i> spp. isolates were resistant to penicillins, sulfonamides, aminoglycoside, and tetracycline antibiotics. Multidrug-resistant (MDR) <i>E. coli</i> and <i>Staphylococcus</i> spp. were identified in 13 (14.4%) and 7 (18.9%) isolates, respectively. However, none of the <i>Salmonella</i> isolates were MDR. Of the 90 <i>E. coli</i> isolates, only 9 (10%) and 5 (5.6%) isolates showed the presence of <i>eaeA</i> and <i>stx2</i> virulence-associated genes, respectively. However, both <i>eaeA</i> and <i>stx2</i> genes were identified in four (4.4%) isolates. None of the <i>E. coli</i> isolates carried the <i>hlyA</i> and <i>stx1</i> virulence-associated genes. The <i>E. coli</i> AMR associated genes <i>bla_CTX-M</i>, <i>bla_TEM</i>, <i>bla_SHV</i>, <i>aac(3)-IV</i>, <i>qnrA</i>, and <i>tet(A)</i> were identified in 7 (7.8%), 5 (5.6%), 1 (1.1%), 8 (8.9%), 4 (4.4%), and 6 (6.7%) isolates, respectively. While the <i>mecA</i> gene was not detected in any of the <i>Staphylococcus</i> spp. isolates. Regarding migratory wild bird species, bacterial recovery, mixed infection, MDR, and AMR index were relatively higher in aquatic-associated species. Overall, the results showed that migratory wild birds around Al-Asfar Lake could act as a reservoir for AMR bacteria enabling them to have a potential role in maintaining, developing, and disseminating AMR bacteria. Furthermore, results highlight the importance of considering migratory wild birds when studying the ecology of AMR.