Changes Of Pathogenic Bacteria Distribution And Drug Resistance In Pediatric Blood Culture In A Tertiary Hospital For Six Consecutive Years

Objective:To explore the positive rate of blood culture,the demographic distribution of positive blood culture samples,the composition of pathogenic bacteria and the change of drug resistance of common pathogenic bacteria in children hospitalized in the pediatric system of a general hospital in binzhou city,shandong province,so as to provide reference for clinicians in the diagnosis of bloodstream infection and empirical drug use in children.Methods:Analyzed retrospectively from January 2014 to December 2019,a general hospital in binzhou city blood culture positive for children,933 cases of pediatric system,basic medical records of children,the pathogenic bacteria isolated from the blood culture and drug sensitive tests such as counting data use frequency and constituent ratio of statistical description,and blood culture positive for children can be divided into three years(2014～2016)before and after three years(2017～2019),through chi-square test or Fisher’s exact probability method to explore the blood culture positive for children changes the distribution of the demographic characteristics,dynamic to the common pathogenic bacteria and drug resistance of change.All data were set up with Microsoft Office Excel 2010,SPSS 22.0 software and WHONET 5.4 system were used for statistical analysis.Results:1.Positive rate of blood culture:a total of 38,877 cases of hospitalized children in a general hospital in binzhou were tested in blood culture for six consecutive years,and 933 pathogenic bacteria were isolated,with a total positive rate of 2.4%.2.Demographic distribution characteristics:825(88.4%)children with positive blood culture were newborns and infants.There were 567 male cases,accounting for 60.8%.The most positive cases in the neonatal ward were 285(30.6%).By comparing the change trend of the number of positive cases of blood culture in children before and after three years,the age composition ratio was mainly changed from the neonatal group and the infant group in the previous three years to the neonatal group and the infant group(χ2=25.531,P<0.001),and there was no significant difference in gender and detected seasonal composition ratio(P>0.05).3.Composition ratio of pathogenic bacteria:gram-positive bacteria were the main pathogens(617 strains,composition ratio of 66.1%),and the most common pathogens were staphylococcus aureus(169 strains,composition ratio of 18.1%),staphylococcus epidermal(124 strains,composition ratio of 13.3%),and streptococcus pneumoniae(73 strains,composition ratio of 7.8%).Gram negative bacteria(301 strains,constitution ratio 32.3%),the most common pathogenic bacteria are escherichia coli(89 strains,constitution ratio 9.5%),klebsiella pneumoniae(58 strains,constitution ratio 6.2%),acinetobacter baumannii(16 strains,constitution ratio 1.7%).Fungi(15 strains,composition ratio 1.6%),mainly candida albicans;Different age groups were predominantly gram positive bacteria,staphylococcus aureus in newborn group(122 strains,constitute more than 25.2%)and school age group(17 strains,constitute more than 48.6%)of the highest,baby group is given priority to with the epidermis staphylococcus(35 strains,constitute more than 21.5%),s.pneumoniae in the children group(34 strains,constitute more than 19.1%)and preschool group(17 strains,constitute more than 23.3%)accounted for the highest.Compared with the previous three years,the composition ratio of gram-positive bacteria increased from 63.6%to 68.8%(χ2=2.82,P<0.05),and that of staphylococcus aureus increased from 15.5%to 20.8%(χ2=4.514,P<0.05).There was no significant difference in the composition ratio of gram-negative bacteria and fungi(P>0.05).4.The highest drug resistance rate of staphylococcus aureus to penicillin G and ampicillin was 95.3%,and the highest drug resistance rate of staphylococcus epidermidis to penicillin G and ampicillin was 93.5%.The drug resistance rate of streptococcus pneumoniae to macrolide antibacterial drugs was above 90%.Linezolid and vancomycin resistant strains were not detected in the main gram-positive bacteria.Among gram-negative bacteria,escherichia coli had the highest drug resistance rate to ampicillin(85.4%)and was sensitive to imipenem,meropenem,piperacillin/tazobactam.The highest resistance rate of klebsiella pneumoniae to piperacillin was 53.4%,and the most sensitive to amikacin.The resistance rate of acinetobacter baumannii to all kinds of antibacterial drugs was less than 30%.The detection rates of methicillin-resistant staphylococcus aureus(MRSA)and methicillin-resistant staphylococcus epidermidis(MRSE)were 23.7%and 74.2%,respectively.The detection rates of escherichia coli and klebsiella pneumoniae were 42.7%and 44.8%,respectively.The detection rate of carbapenems resistant klebsiella pneumoniae(CRKP)(imipenem or meropenem)was 8.6%.Compared with the previous three years,the detection rate of escherichia coli producing super broad-spectrum bacillus lactamase(ESBLs)increased from 32.7%to 55.0%(χ2=4.495,P<0.05),and the detection rate of carbapenem resistant klebsiella pneumoniae(CRKP)increased from 0.0%to 20.0%(χ2=4.907,P<0.05).There was no significant difference in the drug resistance rate of other major pathogens(P>0.05),Conclusions:1.The total positive rate of blood culture in this study was 2.4%,lower than that in other domestic studies of the same type,suggesting that the clinical indications for blood culture submission should be clarified and the collection and submission process should be further standardized.2.Blood culture positive children are mainly distributed in the neonatal and infant groups and tend to develop in a lower age group.3.The pathogenic bacteria isolated by blood culture of children were mainly gram-positive bacteria,and the common pathogenic bacteria were staphylococcus aureus,staphylococcus epidermis and escherichia coli,respectively.The types of common pathogens are different at different ages.According to the comparative analysis between 2014～2016 and 2017～2019,the composition ratio of gram-positive bacteria was on the rise,and the composition ratio of staphylococcus aureus was on the rise.Clinical attention should be paid to the above bacterial infections.4.In this study,MRSA,MRSE,esbls-producing strains and CRKP multi-drug resistant bacteria were detected.Through comparative analysis from 2014 to 2016 and from 2017 to 2019,the detection rates of esbls-producing strains and CRKP of escherichia coli were significantly increased,suggesting that the form of drug resistance was severe in recent years,so the monitoring of drug resistance of pathogenic bacteria should be strengthened,and the use of antibacterial drugs should be standardized to delay the emergence of multi-drug resistant bacteria.