From 2004 to 2005 in our hospital clinical surveillance of antimicrobial resistance commonly
Authors: Zhuo Chao Wen-Xiang Huang Zheng-line
Chongzhi Xia Du Yu-ping-ping
【Abstract】 Objective To investigate the surveillance of
antimicrobial resistance in China to help group (CHINET) Working Group in Chongqing in November 2004 ~ November 2005 on a variety of common clinical bacterial antimicrobial resistance status quo. Method of drug susceptibility testing using disc diffusion method, drug resistance data analysis software used WHONET5. The results of a year for the first time in our hospital were collected from patients with isolates 1380; Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, coagulase-
negative staphylococcus, Staphylococcus aureus, Enterobacter Enterobacter, and Enterococcus faecalis were the most common bacteria, the respective proportions of 18.6%, 13.6%, 11.3%, 10.0%, 9.4%, 9.1%, 8.0% and 3.9%. Enterobacteriaceae resistant
to imipenem and meropenem for the lowest rate, producing extended spectrum β lactamases (ESBLs) in Escherichia coli and Klebsiella pneumoniae strains detection rates were 37.5% and 31.4%; all strains produced ESBLs were sensitive to imipenem and meropenem, Pseudomonas aeruginosa to imipenem and meropenem resistance rates were 37.2% and 39.4%, to ceftazidime resistance rate of 48.9% , and the emergence of pan-resistance to all drug-resistant strains. Acinetobacter
baumannii to imipenem and meropenem sensitive rates were 98.6%
and 92.8% to cefoperazone / sulbactam sensitivity rate, intermediate rate, resistance rates were 34.8%, 27.5%, 37.7 %. Drug combination analysis showed that pairs of cefoperazone / sulbactam is not sensitive to strain has 58 for the same
resistance patterns, PFGE analysis, these strains mainly from
two clone. In addition to carbapenem-sensitive, the other
drugs are resistant, of which 46 come from the same ward. Conclusion hospital nearly six months of drug resistance of common bacteria monitoring results with previous similar, but in some intensive care unit because there is resistance to cefoperazone / sulbactam epidemic strain, so that Acinetobacter baumannii to cefoperazone / sulbactam The sensitivity was significantly lower than the early results of
monitoring. To take effective measures to control the epidemic strain continues to spread is very important.
Key words bacterial resistance to antimicrobial agents of Gram-positive cocci Gram-negative bacilli
Surveillance of bacterial resistance from a hospital
ABSTRACT Objective To investigate the antimicrobial resistance of clinical isolates from a hospital in Chongqing during 2004 to 2005 according to CHINET project. Methods Disc diffusion test (KB methods) was employed to study the
antimicrobial resistance. WHONET5 was applied for analysis. Results In one year of study, 1380 strains were collected which were isolated firstly from each patient. E.coli, P.aeruginosa, K.pneumoniae, A.baumannii, coagulase negative
staphylococci, S.aureus, Enterobacter cloacae and E.faecalis were the most common strains among isolates. The resistant rate of enterobacter to imipenem and meropenem were the lowest. The incidence of E.coli and K.pneumoniae producing ESBLs were 37.5% and 31.4%, respectively. All the ESBLs
strains are susceptible to imipenem and meropenem. 37.2 %, 39.4% and 48.9% of P.aeruginosa were resistant to imipenem, meropenem and ceftazidime, respectively, and pandrug
resistant (PDR) strains of P.aeruginosa have exhibited in our
hospital. All strains of A.baumannii were susceptible to imipenem and meropenem, while only 34.8% of the strains were susceptible to cefoperazone / sulbactam. There are 58 strains shown the same resistant pattern among non susceptible
strains of A.baumannii, and 46 of 58 isolated from the same ward. Conclusion The surveillance results in this year were similar with that in last year. There may be cloning strains of resistant to cefoperazone / sulbactam in some ICU, which resulted in the resistant rate of cefoperazone / sulbactam were higher than before. It is important to take measures to control the transmission of cloning strains in the hospital.
KEY WORDS Bacterial resistance; Antimicrobial agents; Gram positive cocci; Gram negative bacilli
Bacterial resistance emergence and spread of serious impact on human health. Bacterial resistance to antibiotics can lead to ineffective treatment, infection aggravated or even death. To curb the spread of bacterial resistance, the WHO established in 2000 to curb drug-resistant bacteria worldwide
development strategy. Organization of the National Institute of Fudan University antibiotics east, west, south, north, 8 3 A-level hospitals in China was set up surveillance of antimicrobial resistance Assistance Team (CHINET), consecutive collected on a daily basis the clinical monitoring of drug-
resistant bacteria to keep abreast of important pathogen resistance dynamics and change. In this study over the past year the CHONGQING workstation monitoring data analysis to
understand the Chongqing area common clinical isolates to commonly used antimicrobial drug resistance status.
1 Materials and methods
1.2 bacterium from
The First Affiliated Hospital of Chongqing Medical University, November 1, 2004 to November 30, 2005 clinical isolates collected in order to inpatients mainly a small amount of outpatients.
1.2 Identification of bacteria
Strains identified as conventional methods, or API, VITEK Identification System.
1.3 Drug sensitivity test
With KB (Kirby-Bauer) method. Paper, and MH
susceptibility BD media products for the United States. Quality control strains of Staphylococcus aureus ATCC25923, Pseudomonas aeruginosa ATCC27853, E. coli ATCC25922 and β
lactam / β lactamase inhibitor complex quality control from the control of Escherichia coli ATCC35218 Fudan University, Institute antibiotic. Test methods and determine the standard according to the U.S. Clinical Laboratory
Standards Institute (CLSI) 2005 edition of the provisions of [1] (cefoperazone / sulbactam Pfizer pharmaceutical companies based on standards). Producing extended-spectrum β
lactamases (ESBLs) strain confirmed double disk diffusion method, antimicrobial agents for the paper Cefotaxime /
clavulanic acid (30μg/10μg) and ceftazidime / clavulanic
acid (30μg/10μg ).
1.4 Analysis Program
Developed by CHINET sensitivity program implementation. Staphylococcus monitoring of drugs, including: ampicillin / sulbactam, oxacillin, I oxazole compound sulfamethoxazole, erythromycin, clindamycin, rifampicin, penicillin G, gentamicin, cefuroxime , cefazolin, cefoxitin (coagulase-
negative staphylococci), vancomycin, levofloxacin; Enterococcus monitoring drugs: ampicillin, high unit gentamicin, erythromycin, ring C sand star, teicoplanin, vancomycin, nitrofurantoin. Enterobacteriaceae and Acinetobacter monitoring drugs: gentamicin, amikacin, ampicillin, ampicillin / sulbactam, piperacillin, imipenem, meropenem, cefazolin, the first spore furosemide Sim,
cefoxitin, cefotaxime, ceftazidime, cefepime, cefoperazone / sulbactam, piperacillin / tazobactam, ciprofloxacin, sulfamethoxazole mouth oxazole compound . Pseudomonas monitoring of drug including: gentamicin, amikacin, piperacillin, imipenem, meropenem, ceftazidime, cefepime, aztreonam, cefoperazone, ceftazidime Piperazine ketone / sulbactam, piperacillin / tazobactam, ticarcillin / clavulanic acid, ciprofloxacin, levofloxacin, SXT A mouth oxazole. Haemophilus spp monitoring of drugs, including: azithromycin,
ampicillin, ampicillin / sulbactam, I oxazole compound sulfamethoxazole, ciprofloxacin, chloramphenicol, cefuroxime, cefotaxime.
1.5 Analysis Method
Drug resistance in clinical isolates of bacteria was used to analyze isolates from patients for the first time;
surveillance of antimicrobial resistance with the World Health Organization recommended WHONET5.3 Center software for analysis. Reposted elsewhere in the paper for free download http://
2 Results
2.1 Strain Distribution
Each patient for the first time to collect a total of 1380 isolates isolated several strains of bacteria listed the top 10, see Tab.1.
Clinical specimens of 2.2 isolates the source
Clinical isolates the main sources of specimens of
sputum, urine and wound pus and secretions, respectively, accounting for 50.2%, 18.1% and 10.2%.
2.3 The main clinical isolates to commonly used antimicrobial drug resistance
(1), Staphylococcus and Enterococcus resistance, see
Tab.2, Tab.3.
(2) The resistance of Haemophilus influenzae see Tab.4.
(3), Enterobacteriaceae and Acinetobacter species resistant see Tab.5. Can be seen from the Tab.5, in addition to Enterobacter cloacae resistant to imipenem and meropenem rate of 3.6%, other Enterobacteriaceae that both drugs are fully sensitive; Escherichia coli and Klebsiella pneumoniae ceftazidime, cefepime, amikacin and piperacillin / tazobactam-
sensitive rate of 70% or more; Enterobacter cloacae cefepime susceptibility rate of 61.8%, second only to imipenem and meropenem, while susceptibility to other drugs are below 37%; resistant Acinetobacter baumannii in serious condition, in addition to high sensitivity to imipenem and meropenem, the sensitivity to other drugs, the rate of 0 ~ 46.4% . Further
analysis of Enterobacter cloacae and Acinetobacter baumannii resistance to combination of models to test drugs for all 13 kinds of benchmarks and found that 138 of Acinetobacter baumannii resistance patterns are 39 species, of which 58
showed the same-resistant bacteria drug model, that is to imipenem and meropenem than 12 kinds of drugs completely resistant, 83.3% of them have come from the same ward, 33.3% from the same sections. PFGE analysis of isolates from two clones of these strains (reported in another paper). While there are 22 species of Enterobacter cloacae resistance
patterns, of which 30.9% of strains showed imipenem and meropenem than 12 kinds of drug resistance patterns completely resistant (Tab.6).
(4) The resistance of Pseudomonas see Tab.7. Can be seen from the Tab.7, Pseudomonas aeruginosa sensitive only to imipenem and meropenem higher, respectively, 62.8% and 60.6%, to ceftazidime, cefepime, piperacillin / tazobactam, amikacin and ciprofloxacin sensitivity rate between 50% ~ 54.3%. 2005 6
July isolated from different patients with drug resistance to all six pairs of pan-resistant strains (pandrug resistant,
PDR), 5 Zhu surgical ward from the three sections, one derived from the internal medicine ward. 2 cases of sputum samples,
urine samples, 2 cases of bile samples in 1 case, pus specimen in 1 case. Pairs of Pseudomonas maltophilia widowed raised outside the antibacterial activity of most bacterial drugs levofloxacin and ciprofloxacin, sensitive rate of 75% and 66.7%, ceftazidime, cefoperazone / sulbactam, ticarcillin / clavulanic acid and compound sulfamethoxazole mouth oxazole sensitive rates were 55.6%
3 Discussion
Since October 2004 set up surveillance of antimicrobial resistance in China collaboration group, I have homes in the
western region as a representative of the strains collected over the past year resistance analysis, sum up the following characteristics:
(1) Staphylococcus aureus is still the hospital infections and community acquired infections, the most common
Gram-positive bacteria, the isolation rate ranks sixth in the overall separation rate, reaching 9.1%. In recent years, information, MRSA isolation rate of the general increase in the world. Brssg reported [2], MRSA isolation rate from 1998
to 1999 to 27.6% in 2002 and 2003 to 41.0%. In Shanghai in 2004 monitoring report shows that, MRSA isolation rate was 63.9% (Chu-mei. Of the Sixth National infectious diseases and anti-microbial chemotherapy conference proceedings. In 2005, Shanghai. I have not made the relevant pre-hospital survey,
but over the past six months separation rate has reached 52.4%, are noteworthy. antimicrobial susceptibility results showed that separation of MRSA in our hospital fully sensitive to vancomycin, no vancomycin-intermediate strains (VISA).
pairs of rifampicin-sensitive rate of 47.6%, while the right the general resistance to other drugs. As the venous catheter and other medical implant devices, making it possible to form the Portuguese bacteria, coagulase-negative staphylococci of
clinical significance as an important nosocomial infection pathogen isolation rate ranks fifth in the overall separation rate. survey shows that hospital MRCNS higher than MRSA (76.9% vs52.4%), and the MRSA and MRCNS in addition to all the β
lactam antibiotic resistance, the pairs of macrolides, fluoroquinolones, amino-glycosides SXT A class and I oxazole, etc. The multi-drug resistance trends of antimicrobial agents has also increased. The survey found no vancomycin resistant (VRSA) and intermediate (VISA) strains of Staphylococcus aureus.
(2) of the enterococci isolated in our hospital to mainly Enterococcus faecalis, its ampicillin resistance rate of 36.0%, did not detect resistance to vancomycin and teicoplanin (VRE) strains.
(3), Haemophilus influenzae is a community-acquired
respiratory tract infections common pathogenic bacteria. Susceptibility results showed that, ampicillin, cefuroxime, cefotaxime, and azithromycin against Haemophilus influenzae has a good in vitro antibacterial activity, especially for fully sensitive to cefotaxime, the sensitivity is higher than 2002 National Antibiotic Resistance Monitoring Center reported [3].
(4), Enterobacteriaceae carbapenem the highest
sensitivity, this monitor with my hospital were similar to
previous years. Escherichia coli, Klebsiella pneumoniae to cefepime, ceftazidime, piperacillin / tazobactam and amikacin sensitivity rate of 80% or more. ESBLs detection showed that Escherichia coli and Klebsiella pneumoniae ESBLs detection
rates were 37.5% and 31.4%, Escherichia coli sensitive to cefotaxime rate was only 46.1%, lower than ceftazidime (78.9%) that ESBLs in our hospital mainly cefotaxime enzymes (CTX
M-type), which is consistent with reports of many domestic
scholars.
(5), Enterobacter cloacae, and Acinetobacter baumannii to the third-generation cephalosporins (including the enzyme inhibitor complex) resistance rates were generally higher than
the pre-monitoring data [4], in addition to rate of carbapenem-sensitive More than 90% outside of Acinetobacter baumannii susceptibility rates of other drugs were less than 50%; and Enterobacter cloacae sensitive only to cefepime higher sensitivity to other drugs ranged from 0 ~ 37%, study The reason may be an outbreak of epidemic clone. Drug-
resistant portfolio analysis shows that since November 2004 to May 2005, surgical ward there may be a building only carbapenem-sensitive Acinetobacter baumannii strains, with the result so that the whole increase in resistance rates . The
same is found in Enterobacter cloacae. The molecular epidemiology of speculation to be done explicitly. In addition, in Shanghai and Hangzhou region, carbapenem-
resistant Acinetobacter baumannii have been repeated reports of episodes, drug-resistant mechanism and bacterial enzymes produced carbapenem related to [5]. In our hospital since 1998, surveillance has found only a very small number of imipenem-resistant Acinetobacter baumannii, cefoperazone / sulbactam resistance higher than those in Beijing, Shanghai
and Zhejiang area, which may be related to me Hospitals in recent years, extensive use of cefoperazone / sulbactam on. Currently, there is no relevant outside of Acinetobacter baumannii to cefoperazone / sulbactam-resistant mechanism of
reports, studies have suggested that oxytocin Klebsiella bacteria to cefoperazone / sulbactam in a highly-resistant
mechanism and Bacteria produce new β lactamase RbiA
related, to later studies of Acinetobacter baumannii to cefoperazone / sulbactam resistance mechanism stipulates the
right direction.
(6), pan-resistant strains of Pseudomonas aeruginosa is also the first time in the year to monitor the emergence of drug resistance mechanism and the genetic background produced worthy of further study.
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