Title : Extensively drug-resistant gram-negative bacteria: Rapidly spreading blood stream pathogens in Pakistan
Abstract:
The emergence of extensively drug- resistant gram negative pathogens (XDR) has worsens the treatment of blood stream infections (BSI) which results in high morbidity and mortality. This study aimed to detect the prevalence and resistance pattern of XDR Gram-negative bacteria in blood stream infections in a tertiary care hospital in Pakistan.
Materials and Methods: Blood cultures were performed on Bactec Blood Culture System 9050 (Becton Dickinson-USA) and bacterial isolates were identified by gram reaction, growth on different culture media and biochemical reactions, further identification was done by API® (bioMeriéux-UK). Antibiotic susceptibility testing was performed by using agar-diffusion method to detect XDR. For colistin MIC, broth dilution method was used. Clinical and Laboratory Standard Institute (CLSI) recommendation were followed for all the tests and interpretation.
Results: From November 2022 to December 2023, 119 XDR bacterial isolates were recovered on blood culture. Among XDR the most dominating pathogen was S. typhi (n=103, 83.73%), followed by Klaebsiella. Pneumonniae (n=7, 5.88%), Acinetobacter. baumanni, (n=4, 3.356%), Pseudomonas. Aeruginosa (n=4%), 3.36), E.coli (n=1, 0.84%). All the XDR isolates other than Salmonella. typhi showed resistance to carbapenem (Meropenem and Imepem). The MIC values of ceftriaxone tested in Salmonella. Typhi were ≥32 in 63 isolates and ≤32 in 12. Among XDR isolates of Acinetobacter. baumanni Colistin was found intermediate rather than sensitive while all other were sensitive. All XDR isolates were sensitive to tigecycline.
Conclusion: The frequency of extensive drug-resistance is high and limits the treatment options. This further demands for proper sanitation and prevention of irrational use of antibiotics
