The detection of causative agents with rapid molecular biological medhods in late onset hospital acquired pneumoniae

Introduction and Purpose: Patients with late-onset hospital-acquired pneumonia pneumonia (HAP) that develop after the fifth day following admission to the hospital are usually caused by multi-drug resistant bacteria. Late detection of the pathogens and inability to start appropriate antibiotic on time have negative effect on HAP prognosis. The isolation of infectious microorganisms in a short term by fast molecular methods in the last years ensure that treatment can be started earlier and more effectively and this situation is thought to affect prognosis positively. In this study, it was aimed to determine the factors in HAP with rapid molecular methods and to compare the results with conventional methods. Material-Method: Total 62 patients, with HAP diagnosis according to the criteria of ATS/IDSA published in 2005, who were followed-up in the intensive care units of Anesthesia and Reanimation Department and Chest Disease Departments of Ege University Faculty of Medicine between January 2014 and January 2016, were taken into the study. Lower respiratory tract samples were obtained from patients after HAP diagnosis with bronchoscopic (BAL, BASP) and non-bronchoscopic (mini-BAL) methods. The samples were examined in terms of bacteriological agents with conventional methods and fast molecular methods. Results: 62 patients (42 males, mean age: 69.7 ± 15.6), diagnosed with hospital-acquired pneumonia, were included. 95.2% of the patients had comorbid disease. Invasive mechanical ventilation (IMV) was applied to 33 patients and IMV - non-invasive mechanical ventilation (NIV) was applied to 28 patients. At the time of hospital-acquired diagnosis; 39 of 59 patients had unilateral infiltration and 20 had bilateral infiltration on chest x-ray. Chest x-ray of three patients showed pleural effusion and increased density consistent with unilateral infiltration. Bacterial agent was detected in 40 (64.5%) of 62 patients with conventional method, whereas bacterial agent was isolated in 57 of 62 patients (91.9%) with polymerase chain reaction (PCR). It has been observed that the conventional method and the PCR method are compatible with each other in terms of detecting the agent (kappa:0.797). Besides, PCR was found to have a significantly higher rate of agent detection (p=0.0004). Acinetobacter baumannii was detected most frequently with both methods. In the follow-up, mortality was observed in 45 (72.6%) of 62 patients. Conclusion: It has been shown in this study that there is a good agreement between conventional methods and PCR in the detection of late-onset HAP agents and that agents can be detected by PCR in more patients. Detection of bacterial agents by rapid molecular methods is thought to lead to the effective treatment of hospital-acquired pneumonia by rapid identification of the causative agents.