Bacteriological Profile of Patients With Stroke-Associated Pneumonia and Antimicrobial Susceptibility of Pathogens: A...

Stroke-associated pneumonia (SAP) is the aftermath of aspiration of oropharyngeal secretions or stomach content. Mechanical ventilation and lowered immunity and consciousness facilitate the etiopathogenesis of SAP. Antibiotic prophylaxis and repeated culture and sensitivity testing dampen the drug susceptibility patterns of the pathogens. We accomplished this study to determine the bacteriological profile of patients with SAP and the antimicrobial susceptibility patterns of the pathogenic bacteria.

This cross-sectional study was executed from August 2022 to May 2024 at Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar, India. We included adult patients who endured treatment in the neurosurgery intensive care unit (ICU) throughout the study period due to a stroke and developed pneumonia within 48 hours of admission. The endotracheal tube (ET) aspirate and bronchoalveolar lavage (BAL) fluid specimens collected from the eligible participants were analyzed. Enriched and selective media such as 5% sheep blood agar, chocolate agar, and MacConkey agar were used to culture pathogenic bacteria. The VITEK 2 system was used to identify isolates and assess antimicrobial susceptibility testing (AST). The pathogenic bacteria and their antimicrobial susceptibility patterns were gauged. We leveraged R software (version 4.4.1) for data analysis.

Two hundred forty bacterial isolates were found in the 181 eligible patients. Forty-eight (26.52%) participants were females. The median age of the study population was 64.50 (58.74-70.24) years. Fifty-nine (32.60%) participants had two different isolates in their culture reports. We found the following non-fermenters: Acinetobacter baumannii (55, 22.92%), Pseudomonas aeruginosa (31, 12.92%), Burkholderia cepacia (6, 2.50%), and Elizabethkingia meningoseptica (4, 1.67%). Klebsiella pneumoniae (88, 36.67%) and Escherichia coli (15, 6.25%) were the most commonly noticed Enterobacterales. Other Enterobacterales were Proteus mirabilis (9, 3.75%), Serratia marcescens (8, 3.33%), Klebsiella oxytoca (3, 1.25%), Enterobacter aerogenes (1, 0.42%), Providentia stuartii (1, 0.42%), and Enterobacter cloacae complex (5, 2.08%). Staphylococcus aureus (14, 5.83%) was the only gram-positive cocci in our study population. The sensitivity of A. baumannii was maximum for minocycline. P. aeruginosa was highly sensitive to imipenem and completely resistant to tigecycline. Minocycline was the only effective drug against E. meningoseptica. Similarly, the Enterobacterales had the greatest sensitivity for tigecycline. All 14 specimens of S. aureus were sensitive to both vancomycin and linezolid. They were responsive to tigecycline as well.

The most common pathogenic bacteria in our study were K. pneumoniae, A. baumannii, P. aeruginosa, E. coli, and S. aureus. Enterobacterales were highly sensitive to tigecycline. A. baumannii and E. meningoseptica had maximum sensitivity for minocycline. All isolates of S. aureus were sensitive to both vancomycin and linezolid. We warrant further research with a larger sample size to investigate the bacteriological profile among other critically ill patients and their AST findings.