Pathogen Profile And Rapid Diagnosis Of Bacteria In Ascites Of Cirrhotic Patients

Objective To investigate the microbiological characteristics and drug resistance of liver cirrhosis patients with spontaneous bacterial peritonitis from 2004 to 2015,and provided a reference to be antibiotics used and rapid etiological diagnosis.To evaluate the clinical application value of polymerase chain reaction(PCR)in the diagnosis of spontaneous bacterial peritonitis(SBP)in patients with liver cirrhosis through the detection of 16 s r DNA.Materials and Methods Source The clinical data and pathogen susceptibility results were collected from clinical microbiological data bank manage system.A total of 138 patients with liver cirrhosis in decompensated periods combined ascites in our hospital from Jan.2015 to Jan.2016 were collected ascites samples and clinical data.Methods Patients,who were admitted from Jan.2004 to Dec.2009 were assigned to group A,those from Jan.2010 to Dec.2015 were assigned to group B.Pathogens present in the ascites was identified,and their sensitivity to various antibiotics was determined.Using bacterial 16 s r DNA gene as the target sequence,specific sequences were selected to establish a rapid diagnostic method in the universal and specific regions.The bacterial DNA in ascites of the 138 patients with liver cirrhosis was detected by this method of our hospital,and the results were compared with the conventional methods.Measurement data and numeration data were statistically analyzed with means ± standard deviations and x2 test respectively.Two sided P<0.05 was considered statistically significant.Results 219(5.08%)positive strains of bacteria were separated from 4308 cases of culture.242 strains of bacteria were cultured(including 23 for more than one pathogen).Of which,91 samples were positive for gram-positive bacteria(37.60%),139 for gram-negative bacteria(57.44%),and 12 for fungi(4.96%).The proportion of G+ in group B was significantly higher than that in group A and in contrast to G-.In B group,the proportion of E.coli was significantly lower than that in group A,and coagulase-negative Staphylococcus was significantly higher than group A.The difference in the proportion of fungus was not significant between A and B groups.Coagulase negative staphylococci had high rates of drug resistance to β-lactam antibiotics(79.6%),and had high sensitivity to dalfopristin,vancomycin,and linezolid.In Enterococcus,the resistance to vancomycin and linezolid was absent,but was high against to common used antibiotics.The resistant rate of E.coli to cephalosporin was high,and the bacterium had sensitivity to β-lactam inhibitor antibiotics(like piperacillin/tazobactam and cefoperazone/sulbactam).The detection rate of extended spectrum β-lactamase(ESBL)E.coli was 7.89%,and the sensitivity to carbapenems was high.Klebsiella pneumoniae was highly resistant to penicillins and cephalosporins.It had a 16.24% resistance rate of piperacillin/tazobactam and had a good sensitivity to carbapenems.C.albicans,C.parapsilosis and C.glabrata were sensitive to amphotericin B,fluconazole,voriconazole,and itraconazole.No strains were found to have resistance to common antifungal drugs. Taking ascites culture positive as SBP diagnostic gold standard,in which the sensitivity of PCR method was 100%,the specificity 37%,the positive predictive value 21%,the negative predictive value 100%,and the difference between the two groups was significant(x2=10.948,P<0.01).If taking ascites culture positive,PMN≥250×106/L as SBP diagnostic gold standard,in which the sensitivity of PCR method was 100.0%,the specificity 36%,the positive predictive value 29.0%,the negative predictive value 100%,and the difference between the two groups was significant(x2=14.338,P<0.01).If taking ascites culture positive,PMN≥250×106/L or(and)peritoneal irritation sign positive and anti-infection treatment effective as SBP diagnostic gold standard,in which the sensitivity of PCR method was 100%,the specificity 61%,the positive predictive value 75%,the negative predictive value 100%,and the difference between the two groups was significant(x2=62.858,P<0.01).Conclusions Enterobacteriaceae bacterium is still the main cause of bacterial infection in cirrhotic patients with ascites.The isolation rate of E.coli ranked in the first in G-bacteria,and the drug resistance have an upward tendency.The proportion and resistance of G+ was increased year by year.Candida albicans was the most commonly isolated fungus in ascites of cirrhotic patients.No strains resistant to common antifungal drugs were isolated.Compared with traditional methods(ascites culture and cytology),16 s r DNA method is a more sensitivity and specificity of the detection of ascites in patients with liver cirrhosis.Combined ascites culture,cytology,16 s r DNA and clinical symptoms can improve the sensitivity and specificity significantly in SBP diagnosis.