Emergence of High Antimicrobial Resistance among Critically Ill Patients with Hospital-Acquired Infections in a Tertiary Care Hospital

Background and Objectives: Inappropriate antibiotic usage in hospitalized patients contributes to microbial resistance. Our study aimed to examine the incidence of clinical bacterial isolates and their antibiotic resistance burden among critically ill patients in different hospital units. Materials and Methods: A single-centered cross-sectional study was conducted in a 120-bed tertiary care hospital that included 221 critically ill patients with hospital-acquired infections. Bacterial cultures and sensitivity reports were obtained and followed by a formal analysis of the antibiogram results to explore recovered isolates' prevalence and antibiotic susceptibility patterns. Results: Gram-negative bacteria were the most predominant pathogens among recovered isolates from the various hospital units (71%). Klebsiella sp. was the most prevalent microbe, followed by Acinetobacter sp., with an incidence level of 28% and 16.2%, respectively. Among the Gram-positive organisms, the coagulase-negative Staphylococci were the most predominant organism (11.3%), while (6.3%) methicillin-resistant Staphylococcus aureus (MRSA) isolates were recovered from different hospital units. Antibiotic sensitivity testing showed that polymyxin B was the most effective antibiotic against Gram-negative bacteria, whereas vancomycin and linezolid were the most active antibiotics against Gram-positive pathogens. Moreover, 7% of the Gram-negative bacteria isolated from different units showed positive production of extended-spectrum beta-lactamase (ESBL). Conclusions: The current study describes the high antibiotic resistance patterns in various hospital units that need extra legislation to prevent healthcare providers from misprescription and overuse of antibiotics.

Continuous Versus Intermittent Linezolid Infusion for Critically Ill Patients with Hospital-Acquired and Ventilator-Associated Pneumonia: Efficacy and Safety Challenges

High variability of linezolid blood concentrations with partial subtherapeutic levels was observed in critically ill patients who received a standard intravenous dose of linezolid, contributing to drug resistance and toxicity. Continuous infusions of linezolid have been suggested as an alternative and provide good serum and alveolar levels without fluctuations in trough concentration. This study aimed to assess the effectiveness and safety of continuous linezolid infusion versus the standard regimen in critically ill patients. A prospective randomized controlled study was conducted on 179 patients with nosocomial pneumonia. Patients were randomized into two groups. The first group received IV linezolid 600 mg twice daily, while the second group received 600 mg IV as a loading dose, followed by a continuous infusion of 1200 mg/day (50 mg/h) for at least 8−10 days. The continuous infusion group showed a higher clinical cure rate than the intermittent infusion group (p = 0.046). Furthermore, efficacy was proven by greater improvement of P/F ratio (p = 0.030) on day 7 of treatment, a lower incidence of developing sepsis after beginning treatment (p = 0.009), and a shorter time to reach clinical cure (p < 0.001). Hematological parameters were also assessed during the treatment to evaluate the safety between the two groups. The incidence of thrombocytopenia was significantly lower in the continuous infusion group than in the intermittent infusion group. In addition, a stepwise logistic regression model revealed that the intermittent infusion of linezolid was significantly associated with thrombocytopenia (OR =4.128; 95% CI = 1.681−10.139; p =0.001). The current study is the first to assess the clinical aspects of continuous infusion of linezolid beyond pharmacokinetic studies. Continuous infusion of linezolid outperforms intermittent delivery in safety and improves clinical effectiveness in critically ill patients with Gram-positive nosocomial pneumonia.