Detection of CTX-M gene in extended spectrum β-lactamases producing Enterobacteriaceae isolated from bovine milk

• Main Author: Ihsan M. Ahmed
• Format: Article
• Language: Arabic
• Published: University of Mosul, College of Veterinary Medicine 2021-02-01
• Series: Iraqi Journal of Veterinary Sciences
• Subjects: milk; pcr; enterobacteriaceae; esbl-e; ctx-m
• Online Access: https://vetmedmosul.com/article_167613_6bca8e1a463ab10709d1cd9b89e39d9f.pdf

Extended spectrum β-lactamases producing <em>Enterobacteriaceae</em> (ESBL-<em>E</em>) have emerged recently as the main cause that facilitates the spreading of antibiotic resistance worldwide. Due to its composition and nutritive values, raw cow milk is vulnerable to bacterial contamination from different sources, especially ESBL-<em>E</em>. Accordingly, present study aimed to detect the ESBL-<em>E</em> in the raw milk of healthy cows. 80 raw cow milk samples were collected from unorganized farms and cows belong to individual owners and investigated for the presence of ESBL-<em>E</em> with the main focusing on CTX-M type. The bacterial isolation was performed using selective MacConkey agar plus cefotaxime (MC<strong>⁺</strong>), while PCR was used to confirm the species of the isolated bacteria and presence of CTX-M gene. The results showed that 28.75%(23/80) samples were ESBL-<em>E</em> positive and distributed as following, 82.61%(19/23) were pure <em>E. coli</em> isolates, 4.35%(1/23) was pure <em>K. pneumoniae</em> isolate and finally, 13.04%(3/23) were mixed of both <em>E. coli</em> and <em>K. pneumoniae</em> isolates. Moreover, the total number of positive ESBL-<em>E</em> was 26 isolates with the majority of them were belong to <em>E. coli</em> and recorded 84.61%(22/26), while <em>K. pneumoniae</em> was recorded less 15.39%(4/26). Additionally, the CTX-M gene was successfully identified in all ESBL-<em>E</em> positive isolates by using PCR, including <em>E. coli</em> and <em>K. pneumoniae</em> isolates. The results of this study assert the importance of raw cow milk as a potential source of ESBL-<em>E</em> that might be transmitted to humans.