Antibiotic Resistance Pattern of Bacteria Isolated from Specimens of Cultures from Intensive Care Units

Intensive care units (ICU) still face a high risk of primary and nosocomial infection. Pathogens in ICU are generally becoming more resistant to antimicrobial drugs, but there are differences between countries, possibly moving to different antibiotic usage patterns. It seems necessary to have adequate knowledge about local microbes and their sensitivity patterns in order to prepare an effective experimental treatment protocol in the ICU. In this study, the bacteriological profile and antibiogram of cultures performed in the ICU are investigated.

The cross-sectional study examined all culture samples obtained from patients in four intensive care units at Imam Reza Hospital, Mashhad, Iran, during 2016 to 2019. Culture and antibiogram information was extracted from the HIS system and compared with patient files whenever necessary. In order to analyze the data, SPSS software was used along with the Chi Square test.

In total, 1569 samples were examined, and 674 (42.95%) were positive for microbial culture. As the most commonly isolated bacteria, Acinetobacter accounted for 32.9% of the cases in 222 cases. Candida accounted for 85 cases (12.6%), Staphylococcus aureus 81 cases (12%), and Klebsiella 59 cases (7.8%). Colistin, the most effective antibiotic against Acinetobacter, showed a resistance rate of 0.9%, whereas carbapenems were not effective against over 95% of these bacteria.

Acinetobacter was the most common Gram-negative bacillus in intensive care units, accounting for more than half of infections. In addition, most of the tested antibiotics, except colistin, were resistant to these strains. Since these microorganisms are multidrug resistant, it is crucial that infection control processes in intensive care units are reviewed and standard antibiotics are prescribed.