Abstract:
This cross-sectional study was conducted between January and June 2020, in five large
poultry slaughter slabs in Dar es Salaam, Tanzania. Purposive sampling was used to select broilers
and spent layers, from which meat and cloaca swabs were collected to determine the occurrence of
multidrug resistant (MDR) Escherichia coli. Identification of isolates was done using API 20E, and
antimicrobial susceptibility testing was performed as per CLSI (2018) guidelines. EBSL (CTX-M, TEM,
SHV) and plasmid mediated quinolone (qnrA, qnrB, qnrS and aac(60)-Ib-cr) were screened using PCR.
Out of 384 samples, 212 (55.2%) were positive for E. coli, of which 147 (69.3%) were resistant to multiple
drugs (MDR). Highest resistance was detected to tetracycline (91.9%), followed by sulfamethoxazoletrimethoprim
(80.5%), ampicillin (70.9%), ciprofloxacin (40.2%) and 25% cefotaxime, gentamycin
(10.8%) and imipenem (8.6%) (95% CI, p < 0.01). Out of the E. coli-positive samples, ten (10/212) (4.7%)
were ESBL producing E. coli, of which CTX-M was detected in two isolates and quinolones resistant
gene (qnrS) in eight, while TEM, SHV, qnrA, qnrB and aac(60)-lb-cr were not detected. The high level
of resistance and multidrug resistance imply these antibiotics are ineffective, add unnecessary cost to
poultry farmers and certainly facilitate emergence and spread of resistance.
