LAUSR

Bloodstream infection or bacteremia refers to the persistence of pathogens invading the blood circulation, which rapidly spreads and causes systemic symptoms such as chill, fever, skin rash and hepatosplenomegaly (Mwaigwisya et al., 2015). Its pathogens mainly include bacteria and fungi and the prognosis is poor (Nieman et al., 2016; Kothari et al., 2014; Altuntas & Korukluoglu, 2019; Silva et al., 2020; Figueroa-González et al., 2019). In recent years, due to the abuse of antibiotics, the increased application of various invasive diagnostic techniques such as intravascular catheters, the incidence of bacteremia has been increasing during the past several decades, with a mortality rate of up to 30% (Ozsurekci et al., 2016; Conn et al., 2017). Therefore, early diagnosis and treatment of bacteremia is particularly critical. Currently, blood culture is considered as the gold standard for diagnosing bacteremia (Singh et al., 2018). However, it takes three to five days to generate positive results and the positive rate is quite low. Thus, patients with bacteremia cannot get timely and accurate diagnosis and treatment. In addition, molecular diagnostic tools such as real-time PCR (PCR), Sanger sequencing, peptide nucleic acid + fluorescence in situ hybridization (PNA + FISH) have been studied and applied in clinical laboratories (Sabat et al., 2017; Rabensteiner et al., 2015). However, the procedures of these methods are complicated time-consuming, which makes them difficult to provide early diagnosis for bacteremia.