[Distribution and antibiotic resistance analysis of Gram positive cocci in bloodstream infections in a hospital in Inner Mongolia].

ABSTRACT

To investigate the strain composition and drug resistance characteristics of G+(Gram positive cocci) cocci causing bloodstream infections in the People's Hospital of Inner Mongolia Autonomous Region in recent years and provide a basis for the empirical and rational use of drugs for the prevention and treatment of bloodstream infections caused by G+cocci. The strain composition and drug-resistant characteristics of G+cocci isolated from positive blood culture specimens sent to various departments of the Inner Mongolia Autonomous Region People's Hospital from January 2015 to December 2022 were retrospectively analyzed, and the higher detection rates of Staphylococcus hominis and Staphylococcus epidermidis, Enterococcus faecium and Enterococcus faecalis, and methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) were examined. MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) were comparatively analyzed for resistance. The resistance data were analyzed by Whonet 5.6 statistical software, the significance of difference was analyzed by SPSS 22.0 software, and the resistance rate was compared by χ2 test. The results showed that 1 209 strains of G+cocci, in terms of the composition ratio, from high to low, were mainly human staphylococci (32.5%,393/1 209), Staphylococcus epidermidis (27.8%, 336/1 209), Staphylococcus aureus (14.9%,180/1 209) and Enterococcus faecalis (10.6%, 128/1 209). Among them, the detection rate of methicillin-resistant Staphylococcus aureus (MRSA) (42.8%, 77/180) was lower than that of methicillin-resistant coagulase-negative staphylococcus (MRCNS) (71.5%, 608/850); and among enterococci, the detection rate of Enterococcus faecalis (71.5%, 128/179) was much higher than that of Enterococcus faecalis (28.5%, 51/179). For drug resistance, the resistance rate to five commonly used antimicrobial drugs, ciprofloxacin, levofloxacin, moxifloxacin, clindamycin and tetracycline, was higher in Staphylococcus hominis than in Staphylococcus epidermidis (χ2=7.152-64.080, P<0.05); however, for the aminoglycoside antimicrobial drug gentamicin, the rate of resistance in Staphylococcus humanus was lower than in Staphylococcus epidermidis, and the difference was statistically significant (χ2=11.895, P<0.05); no strains resistant to linezolid and vancomycin were found in both. Comparison of the resistance rates to seven antimicrobial drugs, gentamicin, rifampicin, ciprofloxacin, levofloxacin, moxifloxacin, clindamycin and tetracycline, was significantly higher in MRSA than in MSSA (χ2=6.169-56.941, P<0.05); however, the resistance rate to cotrimoxazole, MRSA (15.6%, 12/77) was significantly lower than that of MSSA (35.3%, 36/102), and the difference was statistically significant (χ2=5.155, P<0.05); MRSA and MSSA resistant to linezolid and vancomycin were not found. The resistance rate of Enterococcus faecalis to penicillin G and ampicillin was much higher than that of Enterococcus faecalis, and the difference was statistically significant (χ2=22.965, P<0.05), and vancomycin-resistant enterococci (VRE) were not found. In conclusion, for staphylococci, except for individual antibiotics, S.hominis and MRSA were more resistant to most antimicrobial drugs than S. epidermidis and MSSA, showing a multidrug-resistant pattern. For enterococci, except for penicillin G and ampicillin resistance rate, Enterococcus faecalis is much higher than Enterococcus faecalis, the rest of the antimicrobial drugs did not see a significant difference, in addition to vancomycin-resistant enterococci were not detected. Clinicians should pay great attention to the monitoring data of multidrug-resistant G+cocci isolated from blood cultures to provide a basis for empirical and rational use of drugs in the clinic, to effectively prevent and reduce the incidence of bloodstream infections caused by G+cocci.