The antimicrobial susceptibility pattern of lower respiratory tract infection pathogens in patients with chronic respiratory diseases

Background
Growing concerns surround the escalating issue of antibiotic resistance, primarily caused by the excessive and misuse of antimicrobial agents in healthcare settings and communities worldwide, posing a significant threat, particularly in low-income countries.


Aim
To investigate the exacerbating organisms and antibiotic susceptibility in individuals with chronic respiratory conditions who were presenting with lower respiratory tract infections and to establish the prevalence of antimicrobial resistance, which would facilitate the selection of appropriate antimicrobial treatment in the Chest Department at Tanta University hospitals.


Patients and methods
This prospective nonrandomized observational cross-sectional study was carried out on 100 patients with clinical criteria of chronic respiratory patients. Bronchoalveolar lavage was taken, and culture and sensitivity were done to obtain bacteriological profile and their antibiogram.


Results
Out of 100 cases, 10% of patients showed polymicrobial growth, and 90% showed monomicrobial growth. 82.7% showed Gram-negative organisms, including Pseudomonas aeruginosa (26.4%), Klebsiella pneumoniae (22.7%), Haemophilus influenzae (13.6%), Acinetobacter spp. (12.7%), and Escherichia coli (7.3%). 17.2% showed Gram-positive organisms, including Staphylococcus aureus (9.1%) and Streptococcus pneumoniae (8.2%).
Gram-negative bacteria showed the greatest sensitivity to tigecycline and colistin, as well as aminoglycosides and piperacillin-tazobactam. Conversely, the Gram-positive bacterial isolates were most responsive to linezolid, teicoplanin, and vancomycin.


Conclusion
The use of inadequate antibiotic treatment poses a risk of the emergence of MDR pathogens. An up-to-date antibiogram for each hospital, drawn from local bacteriological patterns and susceptibility data, is crucial for informing the initial choice of empirical treatment.