Detection of Extended-Spectrum Beta Lactamases Selected Genes in Gram Negative Bacteria Isolated from Clinical Specimens by Using Multiplex PCR

Abstract

Extended spectrum B-lactamases (ESBLs) are group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. This study was conducted in Khartoum state. The study was carried out during the period from January 2017 to June 2017, to detect SHV, TEM, VEB, CTX-M, OXA, AmpC and DHA genes in gram-negative bacteria. All isolates (48) were checked for purity by cultured on blood agar and MacConkey agar, and identified macroscopically and microscopically, and then by using API 20E, then cultured on Muller Hinton agar to Antimicrobial susceptibility testing. Bacterial genomic DNA was extracted from each strain by using boiling method. Multiplex PCR was adopted to detect these genes. The results revealed that the blood samples were the most samples which contain large number of ESBLs genes (43.8%) compared with Peritoneal Dialysis and Sputum samples which contain less number of ESBLs genes (12.5%, 6.3% respectively), Acinetobacter baumanni and Pseudomonas aeruginosa were the most bacteria contain large number of ESBLs genes (31.3%, 20.8%), compared with Ralstonia pickettii and Brevundiamonas vesicularis bacteria which contain less number of ESBLs genes (4.2%, 2.1% respectively), And the most sensitive antibiotics against Gram negative bacteria producing ESBLs were Ciprofloxacin and Amikacin (47.9%, 43.8%), compared with Imipenem and Ceftazidime antibiotics were the most resistance antibiotics (93.8%, 89.6%).OXA gene presence in fourteen of isolates (29.2%) which conclude that this gene is the most common one in Gram negative bacteria producing ESBLs. The Statistical Analysis show that there was no association between the presence of ESBLs genes with samples types, bacterial isolates, and antibiotic susceptibility.