Genomic Epidemiology and Emerging Mechanisms of Antibiotic Resistance Among Clinically Significant Bacteria

BackgroundThe never-ending emergence of superbugs casts a shadow over the victorious age of antibiotics. In fact, the triumph of antibiotics was previously viewed in retrospection as our final victory over bacteria. Bacteria like Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli are now raising an alarming number of infections across hospitals and communities around the globe. The objective was to evaluate the implications for antimicrobial stewardship based on identifying the antibiotic resistance profiles, genotype mechanisms, and trends in common pathogenic bacteria found in various hospitals across Iraq. MethodsWe used a two-fold approach that was comprehensive in scope and involved both efficient multicenter surveillance as well as cutting edge genetic analysis to unravel the complex topography of antibiotic resistance. We provided a geographically heterogeneous but diverse set of clinically obtained isolates to participate in hospitals for a period of 24 months and concentrated our efforts on prioritized pathogens K. pneumoniae, A. baumannii, E. coli, P. aeruginosa, and S. aureus that are well known to pose serious threats. Beginning with clinically obtained isolates sourced across the entire globe, we used standardized techniques such as broth microdilution to first undertake phenotyping in a central reference lab to establish microbial identity based on resistance phenotypes to a set of prioritized antibiotics that include carbapenems, third generation cephalosporins, or fluoroquinolones. Finally, we derived data concerning the emergence patterns and geographic distribution of resistant microbes such as MRSA or CRE. We used genome-wide sequencing to unlock information concerning the genetic blueprints for a set of specifically chosen isolates based on their representational diversity across geographic locales, resistance phenotypes, and specific times. ResultsThe sample was made up of Escherichia coli (n = 225), Klebsiella pneumoniae (n = 185), Staphylococcus aureus (n = 135), Pseudomonas aeruginosa (n= 90), and Acinetobacter baumannii (n = 125). Ceftriaxone resistance was found in 80.4% of E. Coli, ciprofloxacin resistance in 45.6%, and meropenem resistance in 15.1%. K. pneumoniae exhibited 38.9% resistance to aminoglycosides and 70.2% resistance to carbapenems. The percentage of MRSA in S. aureus was 55.5%. P. aeruginosa showed 22.2% resistance to colistin, 37.8% resistance to piperacillin tazobactam, and 50.0% resistance to ceftazidime. Imipenem resistance was found in 85.6% of A. baumannii isolates, whereas colistin resistance was found in 28.8% of isolates. In all, 3.4% of isolates are pan-drug-resistant (PDR), 14.6% are extensively drug-resistant (XDR), and 52.1% are multidrug-resistant (MDR). WGS identified common genes such bla_NDM-1, bla_OXA-48, mcr-1, aac (6)-Ib, and plasmid replicons IncF, IncL/M, and IncI2. Carbapenem resistance in Gram-negative bacteria rose by around 18% over the course of five years. ConclusionsThis study shows that the rapid spread of complex genetic information in bacteria causes antibiotic resistance problems. High-level resistance represents an expected consequence of the spread of resistance genes and successful bacteria within healthcare systems. We demonstrate in our results that our expertise in overcoming resistance at a molecular level will play a crucial role in combating infectious diseases in the coming years.