First Report of blaCTX-M-15 Extended Spectrum Beta-Lactamase (ESBL) Producing E. Coli Isolated from Cloacal Swabs of Birds in South Eastern Nigeria

ABSTRACT

Introduction: In this study, we investigated the presence of some beta-lactamases namely SHV, TEM and the most widely spread extended spectrum beta-lactamase (blaCTX-M-15) genes in E. coli isolated from four different bird species including ducks, pigeons, weaverbirds and bats in Ebonyi State, Nigeria. Methodology: Genes for ESBL production was determined based on PCR amplification of the genes encoding the enzymes including TEM, SHV and CTX-M-15 using specific primers. One hundred and fifty cloacal swabs each from ducks and pigeons and 100 each from weaverbirds and bats were respectively collected using sterile swab sticks. Antibiotic susceptibility test on the isolates was conducted using disc diffusion method while the phenotypic determination of ESBL was carried out using Double Disc Synergy Tests (DDST). Observations Results from this study showed that E. coli was present in all the 4 bird species investigated. Of the 117 isolates screened for ESBL production, only 3(5.56 %) and 9(16.67 %), respectively were positive from ducks and pigeons while none was positive from bats and weaverbirds. Results of the molecular studies showed that the ESBL producing E. coli from pigeons were negative for SHV genes, positive for TEM and CTX-M-15 while those from ducks did not harbour any of the beta-lactamase and ESBL genes investigated.  Conclusion: The detection of similar types of beta-lactamase and ESBL genes (TEM and CTX-M-15) in pigeon samples indicates the possible involvement of some bird species in the spread of multidrug resistant genes across human population. This is the first report of CTX-M-15 ESBL in bird species from Southeast Nigeria.