Epidemiology of antimicrobial resistance (AMR) on California dairies : descriptive and cluster analyses of AMR phenotype of fecal commensal bacteria isolated from adult cows

© 2021 Abdelfattah et al..

BACKGROUND: This study describes the occurrence of antimicrobial resistance (AMR) in commensal Escherichia coli and Enterococcus/Streptococcus spp. (ES) isolated from fecal samples of dairy cows and assesses the variation of AMR profiles across regions and seasons following the implementation of the Food and Agricultural Code (FAC) Sections 14400-14408 (formerly known as Senate Bill, SB 27) in California (CA).

METHODS: The study was conducted on ten dairies distributed across CA's three milk sheds: Northern California (NCA), Northern San Joaquin Valley (NSJV), and the Greater Southern California (GSCA). On each study dairy, individual fecal samples were collected from two cohorts of lactating dairy cows during the fall/winter 2018 and spring/summer 2019 seasons. Each cohort comprised of 12 cows per dairy. The fecal samples were collected at enrollment before calving (close-up stage) and then monthly thereafter for four consecutive time points up to 120 days in milk. A total of 2,171 E. coli and 2,158 ES isolates were tested for antimicrobial susceptibility using the broth microdilution method against a select panel of antimicrobials.

RESULTS: The E. coli isolates showed high resistance to florfenicol (83.31% ± 0.80) and sulphadimethoxine (32.45%), while resistance to ampicillin (1.10% ± 0.21), ceftiofur (1.93% ± 0.29), danofloxacin (4.01% ± 0.42), enrofloxacin (3.31% ± 0.38), gentamicin (0.32% ± 0.12) and neomycin (1.61% ± 0.27) had low resistance proportions. The ES isolates were highly resistant to tildipirosin (50.18% ± 1.10), tilmicosin (48% ± 1.10), tiamulin (42%) and florfenicol (46% ± 1.10), but were minimally resistant to ampicillin (0.23%) and penicillin (0.20%). Multidrug resistance (MDR) (resistance to at least 1 drug in ≥3 antimicrobial classes) was observed in 14.14% of E. coli isolates and 39% of ES isolates. Escherichia coli isolates recovered during winter showed higher MDR prevalence compared to summer isolates (20.33% vs. 8.04%). A higher prevalence of MDR was observed in NSJV (17.29%) and GSCA (15.34%) compared with NCA (10.10%).

CONCLUSIONS: Our findings showed high rates of AMR to several drugs that are not labeled for use in lactating dairy cattle 20 months of age or older. Conversely, very low resistance was observed for drugs labeled for use in adult dairy cows, such as cephalosporins and penicillin. Overall, our findings identified important differences in AMR by antimicrobial class, region and season.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:9

Enthalten in:

PeerJ - 9(2021) vom: 01., Seite e11108

Sprache:

Englisch

Beteiligte Personen:

Abdelfattah, Essam M [VerfasserIn]
Ekong, Pius S [VerfasserIn]
Okello, Emmanuel [VerfasserIn]
Chamchoy, Tapakorn [VerfasserIn]
Karle, Betsy M [VerfasserIn]
Black, Randi A [VerfasserIn]
Sheedy, David [VerfasserIn]
ElAshmawy, Wagdy R [VerfasserIn]
Williams, Deniece R [VerfasserIn]
Califano, Daniela [VerfasserIn]
Tovar, Luis Fernando Durán [VerfasserIn]
Ongom, Jonathan [VerfasserIn]
Lehenbauer, Terry W [VerfasserIn]
Byrne, Barbara A [VerfasserIn]
Aly, Sharif S [VerfasserIn]

Links:

Volltext

Themen:

Antimicrobial resistance
California
Cohort study
Dairy cattle
Enterococcus spp
Escherichia coli
Journal Article
Multidrug resistance
Phenotype
Region
Season

Anmerkungen:

Date Revised 22.04.2022

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.7717/peerj.11108

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM325284806