Clinical profile, Antibiotic Sensitivity Pattern and Outcome of Patients with Gram Negative Infections

A BSTRACT Introduction: Infections caused by extended-spectrum beta-lactamase (ESBL)-producing, carbapenem-resistant, and multi-drug resistant (MDR) Gram-negative bacteria especially E. coli and K. pneumoniae are rising globally, posing a serious public health threat due to limited treatment options and high mortality. This study aimed to assess the clinical profile, risk factors, causative organisms, antimicrobial sensitivity, and outcomes in patients with Gram-negative infections at a tertiary care hospital. Methods: A retrospective observational study was conducted at a tertiary care hospital in Coimbatore, India, including patients over 13 years diagnosed with Gram-negative infections during Study Period. Sepsis was defined using clinical and microbiological criteria, including systemic inflammatory response syndrome (SIRS) parameters, positive blood cultures, and organ dysfunction. Patients with incomplete records were excluded. A total of 391 cases were analyzed. Data collected included demographics, comorbidities, infection site, microbiological profile, antimicrobial susceptibility (per Clinical and Laboratory Standards Institute CLSI guidelines), and clinical outcomes. Ethical approval was obtained (IHEC Ref No: PSG/IHEC/2023/Appr/Exp/091). Results: The mean age was 60.4 ± 15.2 years, with 67.2% male patients. Common comorbidities included diabetes (53.3%), hypertension (44.9%), and malignancy (8.7%). Predominant isolates were Klebsiella pneumoniae (30.8%), E. coli (24%), and P. aeruginosa (12.8%). Blood cultures were the main source, followed by urine, tracheal aspirates, and soft tissue samples. MDR organisms (resistant to ≥3 antimicrobial classes) were significantly associated with higher mortality ( P = 0.002) and lower discharge rates ( P = 0.001). ESBL producers had better outcomes, while Carbapenem-resistant enterobacterales (CRE) infections correlated with poorer prognosis. Conclusion: This study highlights the importance of early detection and targeted therapy in managing MDR Gram-negative infections, which is associated with poor outcomes and high mortality. The findings support the need for strong antimicrobial stewardship in hospitals to optimize antimicrobial use and improve patient care. Further prospective studies are needed to explore mortality drivers and develop tailored interventions.