Antimicrobial Resistance Patterns in Bacterial Bloodstream Infections

Bacterial bloodstream infections remain a leading cause of morbidity and mortality worldwide, compounding the challenge of sepsis management in both high-income and resource-limited settings. Gram-negative species such as Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa frequently predominate, while Staphylococcus aureus and coagulase-negative staphylococci remain important Gram-positive pathogens. Over the past decade, the emergence and global dissemination of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamases and carbapenemases have severely undermined the efficacy of penicillins, cephalosporins and even last-resort carbapenems. Rates of multidrug resistance now exceed 30–50% in many centres, driving reliance on agents such as tigecycline, colistin or novel β-lactam–β-lactamase-inhibitor combinations. Geographic variability in resistance prevalence reflects local antibiotic usage, infection-control capacity and surveillance intensity. Rapid molecular diagnostics and whole-genome sequencing are enhancing our ability to detect resistant clones and track transmission in real time. In parallel, antibiotic-stewardship programmes, stricter formulary controls and robust infection-prevention measures are critical to contain further spread. A cohesive strategy integrating epidemiological monitoring, laboratory capacity building and stewardship is now essential to preserve the effectiveness of existing antimicrobials and inform the development of future therapies.

Research from Nature Portfolio

A prospective cross-sectional study in an Ethiopian diagnostic centre reported an 18.5% positivity rate among suspected bloodstream infection cases, with Klebsiella pneumoniae and Staphylococcus epidermidis as the dominant isolates. Gram-negative bacteria showed highest resistance against ampicillin (80.8%) and lowest against imipenem (5.2%), while Gram-positive pathogens remained uniformly susceptible to vancomycin and daptomycin. Extended-spectrum β-lactamase production was detected in over one-third of Gram-negative isolates, and overall multi-drug resistance reached 41.6%. Notably, carbapenem resistance remained below 6%, suggesting that carbapenem-sparing regimens and strengthened stewardship could slow the rise of carbapenemase-producing strains.

Antimicrobial Resistance Patterns in Bacterial Bloodstream Infections publication trend

The graph below shows the total number of articles in antimicrobial resistance patterns in bacterial bloodstream infections across all publications each year (not limited to Nature Index journals).

Technical terms

Bloodstream infection: Presence of viable bacteria or fungi in the blood, often confirmed by positive blood culture.

Antimicrobial susceptibility: The sensitivity of a microorganism to inhibition or killing by specific antimicrobial agents.

Extended-spectrum β-lactamase (ESBL): Enzymes that confer resistance to penicillins and cephalosporins by hydrolysing their β-lactam ring.

AmpC β-lactamase: A type of β-lactamase that hydrolyses cephamycins and narrow-spectrum cephalosporins and is not inhibited by clavulanic acid.

Minimum inhibitory concentration (MIC): The lowest concentration of an antimicrobial that prevents visible growth of a microorganism in vitro.

Multidrug resistance (MDR): Resistance of a microorganism to at least one agent in three or more antimicrobial categories.

References

1. Molecular Characterization and Epidemiology of Antibiotic Resistance Genes of β-Lactamase Producing Bacterial Pathogens Causing Septicemia from Tertiary Care Hospitals. Antibiotics (2023).
2. Bacteriological spectrum, extended-spectrum β-lactamase production and antimicrobial resistance pattern among patients with bloodstream infection in Addis Ababa. Scientific Reports (2023).
3. Phenotypic Bacterial Isolates, Antimicrobial Susceptibility pattern and Associated factors among Septicemia Suspected Patients at a hospital, in Northwest Ethiopia: Prospective cross-sectional study. Annals of Clinical Microbiology and Antimicrobials (2023).
4. Trends in antibiotic resistance among major bacterial pathogens isolated from blood cultures tested at a large private laboratory network in India, 2008–2014. International Journal of Infectious Diseases (2016).