612 cases of blood culture samples of bacteria distribution and drug resistance analysis of
【Abstract】 Objective To understand the hospital blood culture-positive
samples isolated from bacteria distribution and drug resistance to guide clinical rational use of antibiotics. Method in our hospital 612 cases of blood culture samples carried out by bacterial culture and antibiotic susceptibility testing were analyzed retrospectively. The results were found in 71 patients with positive blood cultures, 74 strains, including
gram-positive bacteria 46, 28-negative bacteria, accounting for 62.2% and 37.8%, Gram-positive bacteria Staphylococcus aureus, coagulase-negative
Staphylococcus mainly to vancomycin, cefoperazone / sulbactam, imipenem more sensitive to Gram-negative bacteria were Escherichia coli, Klebsiella pneumoniae mainly to imipenem, cefoperazone - sulbactam, aztreonam
sensitive. Conclusion pathogenic bacteria isolated from blood culture with Gram-positive bacteria mainly the high rate of antibiotic resistance,
clinical should be enhanced in patients with suspected sepsis, blood culture specimens, accurate and reasonable application of antibiotics as soon as possible to improve the cure rate.
Key words blood cultures the distribution of drug resistance in bacteria
Sepsis is a serious blood infections, dangerous condition, a high fatality rate . Rapid culture for banning blood samples to detect pathogens and susceptibility results obtained at the same time, for a clear and early diagnosis to guide doctors are accurate and reasonable application of antibiotic treatment, improve the cure rate has important clinical significance. The author from December 2005 to April 2008 blood culture samples of bacteria distribution and antibiotic resistance of
retrospective analysis of the situation, the report is as follows.
A clinical data
1.1 General information on selected subjects hospital outpatient and hospital 612 cases of suspected septicemia in patients with blood culture specimens, including 340 cases of male and female 272 cases; 5 ~ 10ml
venous blood collected into blood culture bottles immediately for inspection.
1.2 Methods of blood samples after the injection of special culture bottles, with BacT/Alert-120 blood culture system by bacteria, to prompt
for the kinds of positive change to blood agar, separation of pure cultivation of pathogenic micro-organisms by VITEK32 automatic analysis
system (bioMerieux Company) were identified, the operation process in strict accordance with the "national clinical laboratory operating procedures" to the standard strains of Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922).
1.3 sensitivity test sensitivity test using KB disk diffusion method,
antimicrobial susceptibility results according to the U.S. Committee for Clinical Laboratory Standards (NCCLS) 2005 Edition  to determine the requirements, MH agar, BBL Company purchased from the United States. Susceptibility paper were purchased from the United Kingdom Oxoid company.
1.4 statistical analysis software is available WHONET5.1 statistical analysis.
2.1 The positive rate of blood culture isolates of the bacteria types and composition of the 612 blood culture samples were 74 pathogens were isolated, the total positive rate was 12.1%, of which positive bacteria, 46, of the total isolates 62.2%, negative bacteria 28 of the total isolates 37.8%, Gram-positive bacteria Staphylococcus aureus and
coagulase-negative staphylococci are mostly Gram-positive bacteria
accounted for 32.6%, 47.8%, followed by enterococci, accounting for 19.6%, leather gram-negative bacteria Escherichia coli and Klebsiella pneumoniae in order to dominate, respectively, Gram-negative bacteria accounted for
25%, 21.4%, followed by Pseudomonas aeruginosa bacteria cell, accounting for 17.9%, Table 1.
Table 1 Distribution of pathogens isolated from blood culture constituent ratio (%)
Number of trees than the pathogenic bacteria Staphylococcus aureus
1520.3 constitutes a coagulase-negative staphylococci 2229.7 Enterococcus 912.2 Escherichia coli 79.5 Klebsiella pneumoniae 68.1 Enterobacter cloacae 22.7 Pseudomonas aeruginosa Salmonella 22.7 Acinetobacter baumannii 56.8 Other 22.7 pathogens 45.4 Total 74100
2.2 The main blood culture detection of bacteria resistance of
pathogens to the drug sensitivity tests have shown a variety of antimicrobial agents showed a higher resistance. Gram-positive bacteria
resistant to vancomycin the lowest rate, cefoperazone / sulbactam, imipenem followed by the rest of the antimicrobial resistance rate than those in
Table 2 Common Gram-positive bacteria to antimicrobial drug
resistance rate (%)
Antimicrobial coagulase-negative Staphylococcus aureus penicillin
96.199.2 oxacillin 8475.3 ampicillin 95.395.2 cotrimoxazole 88.290.3 ciprofloxacin 55.150.6 gentamicin 65.275 erythromycin 77.485.4 spore-
oxazoline 50.460.2 vancomycin 00 imipenem 19.720.4 clindamycin 6560.5 of Cefoperazone / sulbactam 15.217.3 reposted elsewhere in the paper for free download http://
Table 3 common gram-negative bacteria to antimicrobial drug
resistance rate (%)
Escherichia coli and Klebsiella pneumoniae antimicrobial drugs ampicillin 95.190.7 aztreonam 34.227.3 amikacin 4035.2 ciprofloxacin 63.568.2 cotrimoxazole 85.390 gentamicin 68.457.5 Cefepime 58.756.9 cefotaxime, ceftazidime 65.367.1 piperacillin 74.872.2 imipenem 1510.2 of cefoperazone 5552.4 piperacillin 74.170.3 - 32.835.6 tazobactam
cefoperazone - sulbactam 28.330 Levofloxacin 51.953.3
High, Table 2. Gram-negative bacteria resistant to antimicrobial
drugs was followed by low rates of imipenem, cefoperazone - sulbactam,
aztreonam, piperacillin - tazobactam, amikacin, the rest of the
antimicrobial drugs have shown a higher tolerance, in Table 3.
Sepsis is a common one of the critical illness, usually refers to bacteria invade the blood circulation, continued to exist, multiply rapidly, causing the body systemic symptoms occur, if not accurate and timely treatment, prognosis is poor. With the improvement of medical standards, a variety of invasive examination and treatment, organ transplant technology, extensive development and anticancer drugs, broad-
spectrum antibiotics, extensive use of immunosuppressive agents, clinical sepsis, no significant decline in the incidence of, and the drug-resistant
strains gradually increased, mortality has not decreased significantly. Blood culture and sensitivity test is to determine the main basis for the diagnosis of sepsis, and accurate treatment of sepsis, one of the key steps, so clinically suspected sepsis, will be required to do so as soon as blood culture tests for clinical early diagnosis and accurate treatment
of sepsis to provide direct based on .
Domestic related literature reports indicate that most of the blood culture was positive at around 10% , the Court in recent years, positive blood culture rate was 12.1%, with basically the same, the
Institute has isolated 74 pathogens, mainly gram-positive bacteria,
accounting for 62.2%, of which coagulase-negative staphylococci,
Staphylococcus aureus majority, accounting for 29.7%, 20.3%, Gram-negative
bacteria accounted for 37.8%, to Escherichia coli, Klebsiella pneumoniae,
accounting for 9.5%, 8.1%, which is different from others reported in the literature , may be due to differences between different regions due to .
Clinical irrational use of antibiotics, so resistance to disease-
causing bacteria have become more common, Gram-positive bacteria resistant
to commonly used antibiotics, the problem more serious, to penicillin, ampicillin, cotrimoxazole resistance rate is very high, to oxacillin, erythromycin, gentamicin resistance rate is high, there is a certain
sensitivity to other antibiotics, especially vancomycin, no resistant strains. Gram-negative bacteria resistance problem than obvious to ampicillin, cotrimoxazole resistance rate is very high, the majority of Gram-negative bacteria producing extended spectrum β-lactamase, to
cefotaxime, Piperazine La Xilin, ceftazidime resistance rates are also considerable, but for complex antimicrobial agents and other relatively low rates of antibiotic resistance.
In short, blood cultures and bacterial pathogens in clinical drug resistance surveillance and drug resistance of pathogenic bacteria to understand an important means of changing the law, but also to guide the clinical doctors an important basis for the rational use of antibiotics,
which helps to reduce or delay the drug resistant strains.
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228. Reposted elsewhere in the paper for free download http://www.hi138 . com