Resistance of Some Bacteria Isolated from Urinary Tract Infections in Elderly Patients to Antibiotics and Detection of β-lactamases in Them

Urinary tract infection is the second-largest infection, especially in elderly people, and the increasing use of antibiotics has led to the emergence and development of resistance in isolated and other bacteria in this study Fifty urine samples from elderly patients with urinary tract infections were collected from both sexes in Mosul city. Twenty-six bacterial isolates were isolated and diagnosed by ordinary bacteriological tests. The isolates were related to the species. <em>Escherichia coli</em>, <em>Klebsiella pneumoniae</em>, <em>Pseudomonas aeruginosa</em> and <em>Proteus mirabilis</em>. After isolation, their resistance to 14 selected antimicrobial agents was tested by the disk diffusion method. The presence of β-lactamases, in general, was detected by acidimetric method, the detection of extended-spectrum β-lactamases(ESBLs) was performed by double disk method, while the detection of AmpC β-lactamases was performed by cefoxitin resistance method. The isolates showed clear resistance to β-lactam antibiotics ranged (50%--92.3%),and to ciprofloxacin, gentamicin, sulfamethoxazole, streptomycin, rifampin with rates; (53.8%),(57.7%), (61.5%), (80.8%), (88.5%), respectively, while they showed reduced resistance to amikacin (15.4%). β-lactamases in general were detected in (96.1%) of the isolates, while (19.2%) of them gave a positive result for the detection of (ESBLs). AmpC β-lactamases were detected in (69.2%) of the isolates as they showed a clear resistance to cefoxitin which indicates that they are potential producers of these enzymes.