The Clinic Features And Prognosis Of Patients With Positive Stenotrophomonas Maltophilia Isolates At Different Sites

Objective To analyze the clinical characteristics and prognosis of patients with positive Stenotrophomonas maltophilia(SMA)isolates from different sites,study the risk factors for mortality in patients with S.maltophilia,and analyze the results of antimicrobial susceptibility of S.maltophilia,so as to provide a reference point for clinical prevention and treatment of S.maltophilia infection and improvement of prognosis of patients.Methods A retrospective study were conducted among 651 patients with positive S.maltophilia isolates from January 2020 to October 2022 in the First Affiliated Hospital of Anhui Medical University.The patients were divided into blood culture group,urine culture group,sputum culture group,bronchoalveolar lavage fluid culture group,abdominal drainage fluid culture group,wound secretion culture group and cerebrospinal fluid culture group according to the source of S.maltophilia.Comparisons between groups for measurement data were performed by independent sample t-test or Mann-Whitney U test according to their normality.The chi-square test or Fisher’s exact test was used to compare groups for the count data.Risk factors affecting the prognosis of patients with S.maltophilia infection at each site were analyzed using binary logistic regression.Results1.A total of 651 samples of S.maltophilia were collected from various sources,including respiratory tract [sputum 53%(348/651),alveolar lavage fluid 8%(52/651)],peritoneal drainage fluid 12%(76/651),wound secretion 10%(66/651),blood 10%(62/651),urine 6%(41/651)and erebrospinal fluid 1%(6/651).S.maltophilia in blood culture group,bronchoalveolar lavage fluid culture group,sputum culture group and cerebrospinal fluid culture group were mainly isolated from ICU,accounting for 77.4%(48/62),88%(46/52),44%(153/348)and 67%(4/6),respectively.Patients in the urinary tract infection group and drainage fluid group were mainly distributed in the hepatobiliary and pancreatic surgery department,accounting for 22%(9/41)and 46%(35/76),respectively.Patients in the secretion culture group were mainly distributed in the burn unit,accounting for 69%(44/66).59 patients had S.maltophilia detected at more than one site.The mortality rate of patients in the alveolar lavage fluid groups,blood culture group and drainage fluid culture group was higher compared with other groups,40.38%,32.26% and 26.32%,respectively.2.Univariate analysis showed that history of surgery during hospitalization,CRRT and treatment with reasonable antibiotics after positive blood cultures were significantly associated with death in the blood culture group(p<0.05).Age ≥65 years,renal insufficiency,carbapenem exposure,antifungal drug exposure,and treatment with reasonable antibiotics were significantly associated with death in the drainage fluid culture group(p<0.05).Admission to ICU,renal insufficiency,catheterization,central venous cannulation,CRRT,carbapenem exposure,glycopeptide exposure,antifungal exposure,and a history of more than two antimicrobial exposures were significantly associated with death in the sputum culture group(p<0.05).Age ≥65y and diabetes mellitus were significantly associated with death in the alveolar lavage fluid culture group(p<0.05).Length of hospitalization ≥5 days,malignancy,history of surgery,ventilator intubation,tracheotomy,CRRT,chemotherapy,cephalosporin exposure,and history of antifungal drug exposure were significantly associated with death in the secretion culture group(p<0.05).3.Multivariate analysis showed that CRRT was an independent risk factor for the death of S.maltophilia patients with bloodstream infection(p<0.05),and rational antibiotic treatment after positive blood culture was negatively correlated with the death of S.maltophilia patients with bloodstream infection(p<0.05).Age ≥65 years,renal insufficiency and history of antifungal drug exposure were independent risk factors for death in S.maltophilia patients with intra-abdominal infection(p<0.05).Exposure to antifungal drugs and glycopeptides was an independent risk factor for death in sputum culture group(p<0.05).4.The antimicrobial susceptibility rates of 651 S.maltophilia strains to tigecycline,minocycline,cefoperazone sulbactam,levofloxacin and TMP-SMZ were 98.8%,97.4%,90.3%,89.4% and 75.0%,respectively.Conclusion S.maltophilia has a high rate of drug resistance and multiple susceptibility factors in the clinical setting,can cause infection at different sites.Clinicians need to be alert to the possibility of S.maltophilia infection in susceptible populations during the administration of broad-spectrum antibiotics,especially after the use of carbapenems.S.maltophilia bloodstream infections and abdominal infections have a high morbidity and mortality rate,and timely standardized treatment can reduce the morbidity and mortality rate.