Ten-year trends in sepsis-causing multidrug-resistant pathogens: a nationwide multicenter laboratory-based...

To characterise the epidemiology of bloodstream pathogens causing sepsis in Pakistan over a 10-year period.

We conducted a retrospective, multicenter laboratory-based surveillance study of blood cultures processed in Pakistan. A total of 45,216 blood culture specimens were analyzed. Clinically significant bloodstream isolates were identified using standard microbiological methods, and antimicrobial susceptibility testing was performed according to Clinical and Laboratory Standards Institute guidelines. Major resistance phenotypes, including extended-spectrum β-lactamase (ESBL) production and methicillin-resistant Staphylococcus aureus (MRSA), were evaluated.

Among 45,216 blood cultures, 4356 (9.6%) yielded clinically significant bloodstream isolates. Gram-negative bacilli (GNB) predominated (2776; 63.7%), followed by Gram-positive cocci (GPC) (1468; 33.7%) and fungi (112; 2.6%). Salmonella Typhi (46.0%) was the most frequently isolated pathogens among GNB, followed by Escherichia coli (14.4%). Among GNB, ESBL production was detected in 23.2% of isolates, with the highest prevalence in Klebsiella pneumoniae (85.9%). Carbapenem-resistant organisms accounted for 9.7%, predominantly K. pneumoniae (42.9%). Furthermore, 12.1% of S. Typhi isolates were multidrug-resistant, and 13.4% were extensively drug-resistant. Among GPC, 43.9% were methicillin-resistant coagulase-negative Staphylococci, and 8.1% were MRSA. By 2030, MDR-ST and XDR-ST exhibiting the most pronounced upward trajectories.

Antimicrobial-resistant bloodstream pathogens associated with sepsis are increasing in Pakistan and are projected to continue rising through 2030. Strengthened surveillance, antimicrobial stewardship, and infection prevention strategies are urgently needed to curb this growing public health threat.