Presence of Antibiotic Resistance Genes in Bacteria Isolated from Raw Cow Milk obtained from Bowen University Dairy Farm.

Abstract

Antibiotic resistance is becoming more prevalent thus posing a severe threat to global health. Bacteria were obtained from raw milk produced on the Bowen University campus using conventional methods. Morphological and biochemical testing were used to carry out phenotypic identification process. Six widely used broad-spectrum antibiotics were used in tests to determine their sensitivity. Bacteria resistant to four or fewer antibiotics were chosen for the amplification of antibiotic-resistance genes while using the 16S rRNA technique for sequencing. Eighty-one isolates were obtained, and the sensitivity patterns revealed 81.8% resistance to cefuroxime and 98.1% resistance to cefixime and amoxicillin/clavulanate (augmentin). Twelve out of the multidrug-resistant isolates were sequenced and they revealed 100% resistance to cefixime and amoxicillin/clavulanate (augmentin), 80% to cefuroxime, and 53.3% and 6.7% to gentamicin and ciprofloxacin respectively. Only ofloxacin showed a sensitivity of 100 percent. The sequenced isolates were identified as Pseudocitrobacter faecalis (-), Escherichia coli (-), Bacillus tropicus (+), Citrobacter koseri (-), Providencia burhodogranariea (-), Enterobacter hormaechei subsp. Xiangfangensis (-), Bacillus pumilus (+), Lysinibacillus boronitolerans (+), Klebsiella aerogenes (-), Klebsiella pneumoniae subsp. rhinoscleromatis (-) 2 isolates, and Acinetobacter baumannii. The TEM, SHV-1 and CTX-M genes were detected in the Citrobacter koseri isolate, while the TEM and SHV-1 genes were also found in the Escherichia coli isolate. The high rate of resistance in bacteria observed is alarming. Adequate milk storage procedures and antibiotic usage in dairy cattle farms must be regulated for safety. It is recommended that antibiotics should not be used in farm animals unless when highly necessary.