Antimicrobial resistance in three pneumonia-causing bacterial species: the global, regional, and local state of the art

Abstract

Background Bacterial pneumonia is one of the most serious diseases worldwide. The emergence of antimicrobial resistance (AMR) magnifies its threat. Diagnosis of pneumonia is hampered by multiple causative pathogens and similar symptoms. Despite global concern, resistant strains are expanding with a remarkable surveillance gap, especially in low- and middle-income countries (LMICs). Aims 1) Highlighting the prevalence, diagnostic approaches, and therapeutic guidelines of Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus as key pneumonia-causing bacteria, and 2) addressing factors that impede effective surveillance. Methods Relevant keywords were used in various databases. Results were filtered by time frame 2019-2025, followed by data selection using the Microsoft Excel application. Results We summarized data from 161 publications, including 97 original papers, 48 reviews, 9 official websites, 6 guidelines, and 1 book chapter dealing with bacterial-hospital-, community-acquired pneumonia (HAP, CAP), and AMR. Exemplifying Egypt as a representative LMIC, the majority of isolates showed high resistance to β-lactams and aminoglycosides, while colistin was the most effective antibiotic. PCR results highlighted the high emergence of β-lactams- (ESBL) and carbapenem-resistance (CR) genes, especially the blaOXA-48, blaNDM, blaVIM, and CTX-M15 among Egyptian isolates. The co-existence of CR with triple-, quadrable-, or more-ESBL resistance genes was reported in Egyptian K. pneumonia isolates. For P. aeruginosa, combination of both blaNDM-1 and blaVIM-1 resistance genes or ESBL and metallo-β-lactamase (MBL) genes were reported in doublet or triplet in only one Egyptian isolate. Virulence genes were detected in both S. aureus and P. aeruginosa Egyptian isolates, while only one K. pneumoniae was found co-harboring both AMR and virulence genes. Conclusions 1) Inappropriate use of antibiotics, maternal awareness/educational background and population's socio-cultural level play a significant role in AMR strains' spread, 2) Limited laboratory tools/infrastructure and healthcare facilities limit AMR strains' surveillance, and 3) Frequent updating national/global control plans is needed.