Isolation and PCR-Based Detection of Antibiotic-Resistant Bacteria from Hospital Environments

Abstract

The proposed study aimed to assess the occurrence and pattern of antibiotic-resistant bacterium in hospital settings both through traditional methods of culture as well as PCR-based molecular identification. Sampling of the environment of different units in Ramadi Teaching Hospital was carried out over a six-month period. A total of 600 environmental samples were sampled in the high-risk environments such as intensive care units, emergency departments, surgical suites, and medical wards by standardized swabbing methods. Traditional culture methods and PCR amplification based on common resistance genes such as mecA, vanA/vanB, blaTEM, blaSHV, blaCTX-M and qnr genes were used in processing the samples. Findings indicated that the hospital was generally contaminated with antibiotic-resistant bacteria in all hospital units. Out of the 600 samples taken, 387 (64.5% of the total samples) were positive by conventional culture test, and PCR-based results revealed the presence of resistant bacteria in 456 samples (76.0% of the total samples). The highest contamination rates were found in intensive care units with 94.7% of samples being positive on PCR. The most commonly isolated organisms were MRSA (34.2%), VRE (28.7%), and ESBL producing Enterobacteriaceae (41.5%). Detection using PCR was more sensitive (89.2% than the traditional culture methods (64.5%). The environmental contamination rates and the clinical infection rates were strongly correlated (r = 0.742, p < 0.001). The research confirms the usefulness of molecular detection systems in monitoring the environment in hospitals and points to the prevalence of the presence of multidrug-resistant organisms in healthcare settings.