Characteristics Of Clinical Feature And Antimicrobial Resistance Of Pathogens In Children With Gram-negative Bacterial Bloodstream Infection In Chongqing Area Between 2017 And 2018

Objective To analyze the clinical characteristics,distribution and antimicrobial resistance of pathogens in children with gram-negative bacterial bloodstream infection(GN-BSI)in a teaching hospital in Chongqing from 2017 to 2018.To inform the prediction of GN-BSI and the choice of antimicrobials for local empiric therapy.Method We conducted a retrospective cohort study from January,2017 to December,2018.Clinical data,bacteriology and antimicrobial susceptibility test results were collected in 443 hospitalized children who were diagnosed with gram-negative bacterial bloodstream infection in Children’s hospital of Chongqing medical university.Result In this study,443 cases of Gram-negative bloodstream infection were confirmed,with a male to female ratio of 1.41/1.Infants younger than 1 year old were the main population(60.7%).Hospital acquired infections were 47.6%,which were mainly seen in neonatology department and hematology department(39.8%,37.4%).Abnormal body temperature(100%),mental fatigue(60.3%),respiratory symptoms(61.4%),gastrointestinal symptoms(54.9%),loss of appetite(37.5%),chills(36.7%),and jaundice(9.9%),hepatomegaly(14.8%),disturbance of consciousness(8.1%),rash(5.9%),spleenomegaly(4.4%)were the main clinical manifestations.The incidence of parts of the signs and symptoms differed among age groups.All the children had abnormal body temperature.The neonates mostly showed hypothermia and low-grade fever(T<38.0℃),while the body temperature of infants were mainly above 38.0℃(62.1%,94.5%,X~2=73.372,P=0.000).There was no significant difference in the incidence of impotence(58.2-64.9%)among all age groups,neither of the loss of appetite(36.3-46.4%).Jaundice mainly occurred in neonates(30.5%).Chills were mainly seen in children older than 1-year(60-71.2%).Respiratory symptoms were more common in newborns than in other age groups(79.4%vs 54.0%),and neonates were mainly manifested as shortness of breath,apnea or breath-holding,while older children were mainly manifested as cough and shortness of breath.Digestive tract symptoms were less common in infants than other age groups(45.0%vs 59.2%).hepatomegaly happened main in non-neonates(18.6%vs 12.8%).Consciousness disturbance(8.1%),rash(5.9%),splenomegaly(4.4%,mostly mild enlargement of 3.7%)were relatively rare,and had no statistical difference among different age groups.49.1%of the children had elevated WBC,12.1%had decreased WBC,the median WBC count was 11.92*10?9/L.The median CRP was 38mg/L.The median PCT was 6.1085ng/m L,and it were significantly higher in neonates than in other age groups(25.93ng/m L vs 3.27ng/m L).The median course of the disease was 2.5 days.68.6%of children had basic diseases which mainly about congenital heart disease(27.8%),neutrophilia(22.3%).And 56.8%of the newborns were premature.Local infection foci were identified in 77.1%of the children,mainly in respiratory,digestive,urinary,skin and mucosal systems.Low respiratory tract infection was the most common focal of local infection in all age groups(36.0-83.3%).Skin and mucosal infection was the main infection foci of the children older than 5-years,19.6%of whom diagnosed with bone marrow suppression due to chemotherapy,And perianal infection,oral ulcer took the leading roles.NEC was also common in the neonates(25.8%).Intrusive procedures were performed in 32.7%of the children,mainly deep vascular catheterization(86.9%)and endotracheal intubation(49.7%).Shock occurred in 17.8%of the children.Overall mortality was 4.5%and 4.3%children were died of BSI.The poor prognosis was significantly associated with ESBLs.Neonates and body temperature<38℃were the risk factors for ESBLs.E.coli(35.4%)and K.P(33.0%)were the main pathogens in this study,followed by Sal(7.4%)and P.A(6.8%).E.coli and K.P produced ESBL in 57.4%and 45.1%,respectively.The drug resistance rates to ceftriaxone were over 50%in both of E.coli and K.P.E.coli keeps sensitive to ceftazidime,cefepime,piperacillin tazobactam,imipenem and amikacin(drug resistance rates were 20.4%,15.3%,5.9%,6.6%and 0.8%,respectively),while 54.3%,51.8%,44.3%,42.1%and 6.0%,respectively in K.P.The drug resistance rate to third-generation cephalosporins was less than 13%in Salmonella.The resistance rate was more than 90%to most third-generation cephalosporins in Pseudomonas aeruginosa,while less than 10%to ceftazidime and carbapenem.Conclusion Children yonger than 1-year old and with underlying diseases were the main population of GN-BSI.Neonates had a worse prognosis than the older children.Neonatology department and hematology department should focus on prevention nosocomial infection.Most of the children had foci infection(68.6%),and 90%in neonates.Lower resoiratory tract were the main infection site for all children.NEC for neonates,perianal infection and dental ulcer for children with medulla regression after chemotherapy as well.Clinical manifestation of neonates mainly were hypothermia,low-grade fever,mental fatigue,loss of appetite,polypnea,apnea,abdominal distension,jaundice.While body temperature above38.5℃,mental fatigue,loss of appetite,chills,cough,polypnea,diarrhea,abdominal pain in older children.The vast majority of neonates had elebated PCT(98.4%),especially higher in neonates than in the others.E.coli(35.4%)and K.P(33.0%)were the main pathogens in this study,followed by Sal(7.4%)and P.A(6.8%).The drug resistance rate of Klebsiella pneumoniae detected in this study was significant,with the resistance rate over 40%to imipenem.However,the resistance of Klebsiella pneumoniae to amikacin was low.Neonates are at high risk for ESBLs infection.Antibiotics with high sensitivity should be used in children with high risk factors.