Nonfermenting Gram-Negative Bacilli (NFGNB) are aerobic, non-motile, non-lactose fermenting, oxidase-negative, catalase-positive coccobacilli that pose a serious threat to critically ill patients. Primarily Pseudomonas aeruginosa (PA) and Acinetobacter baumannii (AB), are NFGNB which are potential multi-drug resistant (MDR) pathogens that are related to ventilator-associated pneumonia (VAP). In Nonfermenting Gram-Negative Bacilli (NFGNB) infections, which are potential multi-drug resistant (MDR) pathogens, pathogenesis is determined not only by bacterial virulence factors but more importantly by the interaction between bacteria and the host immune system. Thanks to their direct immunomodulatory properties, lipoproteins and lipids bind and neutralise toxic bacterial substances. During the acute phase response and inflammation, HDL presents significant structural and functional changes. This study was planned to evaluate the relationship between the changes of the serum lipid metabolism and other inflammation markers with the antimicrobial resistance status and the results in NFGNB VAP patients. Also, we aimed to investigate whether there is a difference in the clinical characteristics of the patients depending on the resistance profile of NFGNB.

This prospective study was performed in adult intensive care unit (ICU) patients. They were intubated endotracheally and received mechanical ventilation (MV) treatment for at least 48 hours in Konya Numune Hospital ICU, which has 42 surgery and medicine beds. The study was conducted between May 2019 and December 2020 and approved by the Ethics Committee of Necmettin Erbakan University Medical School. Informed consents were obtained from the patients who participated in the study or from their relatives. The characteristics of the patients and the sequential changes of the inflammatory response including the lipid profile were recorded.

Inclusion Criteria:

• ICU Patients of 18 years of age and above, with clinical suspicion of VAP as defined in the American Thoracic Society (ATS) guidelines and a simplified version of Clinical Pulmonary Infection Score (CPIS)> 6, with significant NFGNB growth in respiratory cultures and with no signs and symptoms of infection at the time of admission, were included in the study.

Exclusion Criteria:

• Patients with chronic inflammatory disease, hepatic dysfunction, active tuberculosis, malignancy, malnutrition, severe immunosuppression (i.e., neutropenia, HIV positive, organ transplant, having received immunosuppressants or used ≥ 20 mg/day prednisone for two or more weeks in the preceding three months), those that within 72 hours since being included in the study had any extrapulmonary infection other than VAP, as well as those whose respiratory cultures presented bacterial agents other than NFGNB and fungal agents were not included in the study.

The patients who were intubated endotracheally and received mechanical ventilation treatment for at least 48 hours in ICU.