Phenotypic and Genotypic Analysis of Antibiotic Resistance in Proteus vulgaris Isolated from ICU Patients in Baghdad Hospitals

 Proteus vulgaris, a Gram-negative bacterium, is a common cause of human infections, particularly urinary tract infections (UTIs). This study aimed to assess the multidrug resistance patterns of Proteus vulgaris isolated from diverse clinical samples, shedding light on its impact on healthcare-associated infections.

 In this cross-sectional study, 300 clinical samples were collected, including 100 urine samples, 50 wound samples, 50 vaginal samples, 50 blood cultures, and 50 sputum samples. All samples were selected in the same number (50:50), except the urine samples (100) because the urine samples in this study were more available in the collection from the study patients, which gave more advanced UTIs. Phenotypic and molecular techniques were employed to identify and characterize these bacteria, focusing on detecting resistance genes such as UreC and blaCTX-M.

 Among the 300 clinical samples, 150 yielded positive cultures for Proteus species. These isolates were obtained from various clinical samples, including 48% from urine, 32% from wounds, 10% from vagina, 8% from blood, and 2% from sputum. Of the 100 P. vulgaris isolates, 88% harbored resistance genes on chromosomal DNA and plasmids. Specifically, 75% carried the UreC gene, and 50% carried the blaCTX-M gene. The highest prevalence of these resistant genes was observed in urine and wound pus samples.

 This study revealed a concerning prevalence of highly resistant multidrug-resistant (MDR) P. vulgaris isolates, particularly in female urinary tract infections. The genomic presence of the UreC gene, which encodes the urease enzyme, and the blaCTX-M gene, which confers resistance to cefotaxime, underscores the urgency of effective antimicrobial strategies in combating these infections.