[Show abstract][Hide abstract] ABSTRACT: To explore the effects of diagnostic protocols on etiology and outcome in immunocompromised host (ICH) with pulmonary infiltrate.
For this historic control study, ICH with acute respiratory failure (ARF) were eligible as study group (n = 65) in 2009 while another ICH cohort was selected as control group (n = 45) in 2007. The protocol consisted of four parts: judgment possible site, determining probable etiology, checking and feedbacks on laboratory test in 12 hours and reassessment and adjustment treatment in 48-72 hours. The etiologies included infection, noninfection and unknown causes.
Their average age was 45.3 years (range: 22 - 71). Causes of immune suppression were autoimmune disease (n = 69), hematological disorders (n = 21), solid cancers (n = 10) and others (n = 10). When two groups were compared, basic diseases, organ function and disease severity showed no significant difference, but etiologic diagnoses rate (73.8% vs 57.8%), time from ICU admission to diagnosis (4.0 vs 6.8 days) and 28-day mortality (38.5% vs 62.2%) had significant difference (P < 0.05).
Implementation of clinical protocol in ICH with ARF is associated with improved etiologic diagnoses and decreased mortality.
No preview · Article · Mar 2013 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: Gene chip array can differentiate isolated mycobacterial strains using various mycobacterium specific probes simultaneously. Gene chip array can evaluate drug resistance to isoniazid and rifampin of tuberculosis strains by detecting drug resistance related gene mutation. This technique has great potential for clinical application. We performed a retrospective study to investigate the capability of gene chip array in the rapid differentiation of species and detection of drug resistance in mycobacterium, and to evaluate its clinical efficacy.
We selected 39 patients (54 clinical mycobacterium isolates), used gene chip array to identify the species of these isolates and detect drug resistance to isoniazid and rifampin in Mycobacterium tuberculosis isolates. Meanwhile, these patients' clinical data were analyzed retrospectively.
Among these 39 patients whose mycobacterium culture were positive, 32 patients' isolates were identified as Mycobacterium tuberculosis, all of them were clinical infection. Seven patients' isolates were identified as non-tuberculosis mycobacterium. Analyzed with their clinical data, only two patients were considered as clinical infection, both of them were diagnosed as hematogenous disseminated Mycobacterium introcellulare infection. The other five patients' isolates were of no clinical significance; their clinical samples were all respiratory specimens. Clinical manifestations of tuberculosis and non-tuberculous mycobacterial infections were similar. Isoniazid resistance was detected in two tuberculosis patients, while rifampin resistance was detected in one tuberculosis patient; there was another patient whose Mycobacterium tuberculosis isolate was resistant to both isoniazid and rifampin (belongs to multidrug resistance tuberculosis). The fact that this patient did not respond to routine anti-tuberculosis chemotherapy also confirmed this result.
Gene chip array may be a simple, rapid, and reliable method for the identification of most mycobacterial species and detection of drug resistance in Mycobacterium tuberculosis. It is useful in diagnosis, treatment, and hospital infection control of mycobacterial infections, and it may have a great potential for clinical application.
No preview · Article · Sep 2012 · Chinese medical journal
[Show abstract][Hide abstract] ABSTRACT: To investigate the antimicrobial resistance of community respiratory pathogens isolated in China.
The strains of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, S. pyogenes were isolated from patients with community-acquired respiratory tract infections at 14 Chinese hospitals from 2005 to 2007. Etest and disk diffusion methods were used to survey the susceptibility of 14 antibiotics against these strains. These antibiotics included penicillin G, ampicillin, amoxicillin/clavulanic acid, cefaclor, cefprozil, ceftriaxone, cefepime, levofloxacin, gatifloxacin, ciprofloxacin, tetracycline, clindamycin, erythromycin and trimethoprim/sulfamethoxazole (SXT).
A total of 1870 strains were collected including S. pneumoniae (n = 997), S. pyogenes (n = 176), H. influenzae (n = 499) and M. catarrhalis (n = 198). The 2005 - 2007 prevalence of penicillin-susceptible S. pneumoniae (PSSP) were 92.6%, 73.9%, 74.1% and penicillin-intermediate S. pneumoniae (PISP) 4.5%, 9.5%, 14.3% and penicillin-resistant S. pneumoniae (PRSP) 2.9%, 16.6%, 11.6% respectively. 36.9% of S. pneumoniae strains isolated from <or= 6 years old children were penicillin-non-susceptive isolates (PNSSP) and < 22.0% of PNSSP isolated from other age groups. The susceptible rates of beta-lactamase antibiotics to PRSP and PISP isolates were less than 25.0% and 49.2% respectively. From 48.5% to 98.6% PSSP isolates were susceptible to beta-lactamase antibiotics. The susceptible rates of PNSSP and PSSP to erythromycin, tetracycline and SXT were below 7.1% and 32.1% respectively. About 95% S. pneumoniae were susceptible to ciprofloxacin, levofloxacin and gatifloxacin. All of S. pyogenes isolates were susceptible to beta-lactamase antibiotics, and 16.7%, 27.1% and 15.6% Of S. pyogenes isolates were susceptible to erythromycin. 8.5%, 19.9%, 15.3% of H. influenzae and 57.4%, 78.8%, 95.5% of M. catarrhalis produced beta-lactamase during the 3-year period. The susceptible rates of cefepime, ceftriaxone, gatifloxacin, levofloxacin and ciprofloxacin to H. influenzae and M. catarrhalis were >or= 92.9%.
Antimicrobial resistance in S. pneumoniae is rising. The prevalence of PNSSP isolated from children < or = 6 years old is higher than other age groups. Amoxicillin-clavulanic acid, ceftriaxone, cefepime, gatifloxacin and levofloxacin remain highly active against common community respiratory pathogens.
No preview · Article · Nov 2009 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To evaluate the in vitro activity of daptomycin, vancomycin, teicoplanin, tigecycline, ceftobiprole and linezolid against 499 strains of blood-isolated gram-positive cocci.
Determination of the minimal inhibitory concentration (MICs) of daptomycin with microbrothdilution method and the MICs of other 9 antimicrobial agents with agar dilution method against 499 strains of blood-isolated gram positive cocci was carried out. The data was analyzed with WHONET 5.4 software.
The susceptibility rates of staphylococci to daptomycin, tigecycline, linezolid, ceftobiprole, vancomycin and teicoplanin were 100%. All staphylococcus strains were inhibited by daptomycin at a MIC of 1 mg/L. The MIC(50) and MIC(90) of daptomycin were both 0.5 mg/L against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus coagulase-negative (MRSCoN). Among Enterococcus spp, the highest MIC of daptomycin was 4 mg/L. The MIC(50) and MIC(90) of daptomycin were both 2 mg/L against E.faecalis, whereas they were 2 mg/L and 4 mg/L against E.faecium. One strains of linezolid-resistant E.faecalis (MIC: 8 mg/L) was susceptible to daptomycin (MIC: 1 mg/L). Three strains of E.faecium carrying vanA gene with vancomycin MICs above 32 mg/L and teicoplanin MICs also 32 mg/L were susceptible to daptomycin, tigecycline and linezolid. The MIC range of daptomycin against Streptococcus pneumoniae and Streptococcus viridans was 0.032 - 0.25 mg/L and 0.125 - 1.000 mg/L separately.
Daptomycin has excellent in vitro activity against common gram-positive pathogens isolated from blood. It may be a good choice for clinicians to treat drug-resistant gram-positive cocci.
No preview · Article · Apr 2009 · Zhonghua nei ke za zhi [Chinese journal of internal medicine]
[Show abstract][Hide abstract] ABSTRACT: To investigate the homology and resistant mechanism of vancomycin-resistant Enterococci (VRE) isolates.
A total of 9 VRE isolates were collected from 2006 to 2007 at PUMC hospital. The susceptibility of these isolates to 10 different antibiotics including vancomycin was tested by E-test. These strains were processed by brain heart infusion agar screening in the presence of vancomycin (6 microg/ml), and were analyzed for genotypic characteristics using the multiplex PCR. The homology of the isolates was determined by pulsed-field gel electrophoresis (PFGE).
All the 9 VRE isolates were identified as Enterococci faecium. The visual analysis of PFGE patterns revealed 6 different PFGE types. The vanA gene was confirmed by PCR and sequencing in 9 VRE isolates, which were consistent between phenotype and genotype for glycopeptides resistance.
Only vanA genotype was detected in PUMC hospital. Clonal dissemination, horizontal gene transfer, and the selective pressure of antimicrobial agents may contribute to the increase of VRE.
No preview · Article · Nov 2008 · Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae
[Show abstract][Hide abstract] ABSTRACT: To investigate the antimicrobial resistance among the nosocomial gram-negative pathogens from 15 teaching hospitals located in different areas in China in 2005.
A total of 1927 non-repetitive nosocomial gram-negative pathogens were collected from 15 teaching hospitals in different areas in China and sent to the central lab for reidentification and susceptibility testing. The levels of minimal inhibitory concentration (MIC) of 18 antimicrobial agents were determined by agar dilution method. WHONET 5.4 software was used to analyze the data.
The strains of Escherichia coli, Klebsiella pneumoniae, and Proteous mirabilis isolates that did not produce extended spectrum beta lactamases (ESBLs) showed high sensitivity to beta-lactams. The antibiotics with a susceptibility rates over 80% against the strains of Entorobacter cloacae, Enterobacter aerogene, Citrobacter spp, Serratia spp, and Proteous vulgaris producing AmpC enzyme included meropenem, imipenem, and piperacillin-tazobactam, and these 3 drugs showed a susceptibility rate of more than 80% against the ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae. Other antimicrobial agents showing a relatively high activity against Enterobacter spp, Citrobacter spp, Serratia spp and Proteous vulgaris included cefepime (67.3% - 100%), amikacin (67.3% - 95.2%), ceftazidime (52.9% - 100%) and cefoperazone-sulbactam (51.9% - 100%). The susceptibility rate of fluoroquinolones was 34.8% - 36.1% against non-ESBL-producing Escherichia coli and was 13.4% - 17.1% against ESBL-producing isolates. The most active agent against Pseudomonas aeruginosa was polymyxin B (95.6%). The agents with the activity rates of 70% - 80% included meropenem, imipenem, amikacin, and piperacillin-tazobactam. The antibiotic with a high susceptible rate against Acinetobacter baumannii was polymyxin B (98.3%), followed by imipenem (80.8%), meropenem (76.2%), and minocycline (67.4%). The susceptible rates of other agents were all below 60%. The agents with relatively high activity against Stenotrophomonas maltophilia included minocycline (85%), levofloxacin (82.5%), and trimethoprim-sulfamethoxazole (77.5%). The agents with a relatively high activity against Burkholderia cepacia included minocycline (77.2%) and meropenem (61.4%).
Carbapenem, piperacillin-tazobactam, amikacin and cefepime remained relatively high activity against nosocomial Enterobacteriaceae, Non-fermenting pathogens have lower susceptibility to the antimicrobial agents than before.
No preview · Article · Nov 2007 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To investigate the molecular mechanism of multiple-drug and pan-drug resistance among Acinetobacter species.
Non-repetitive 90 carbapenem-resistant strains of Acinetobacter species were collected in Beijing, Guangzhou, and Fuzhou 1999-2004. The homology of the isolates was determined by both pulsed field gel electrophoresis and randomly amplified polymorphic DNA typing. Seven representative clones were selected from the 90 strains of Acinetobacter isolated from different hospitals to be used for further study. Analytical isoelectric focusing was used to measure the isoelectric point of the beta-lactamase. Plasmid DNA was extracted and purified Genes of different beta-lactamase, including bla(TEM--), bla(SHV-), bla(PER-), blaI(MP-), bla(VIM-), and bla(OXA-) genes, in these clone strains were amplified and sequenced. PCR was used to analyze the integrons.
The P clone strain isolated during an outbreak of pan-drug-resistant Acinetobacter species in Peking Union Medical College Hospital 2004 was not susceptible to most common antimicrobial agents tested. The 7 representative clones produced multiple beta-lactamases: TEM-1, high-level AmpC, SHV-type, OXA-23 carbapenemase and IMP-8 and metalloenzyme respectively. One clone produced PER-1 enzyme. These 7 clone strains were resistant to most beta-lactams (including carbapenems), erythromycin, chloramphenicol, and rifampin. Two clone strains were susceptible to cefoperazone/sulbactam and amikacin while 4 clone strains susceptible to levofloxacin. All of the 7 clones were susceptible to minocycline and colistin. Five different integrons were found, harboring the genes mediating the resistance to aminoglycosides, rifampin, chloramphenicol, and carbapenems (bla(IMP-8)).
The molecular bases of multiple-drug or pan-drug resistance in Acinetobacter species include production of OXA-23 carbapenemase or IMP type metalloenzyme and integrons with different resistance gene cassettes. Pan-drug-resistant Acinetobacter species are susceptible to old antimicrobials agents, such as colistin and minocycline.
No preview · Article · Feb 2006 · Zhonghua yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To elucidate the etiology, pathohistology, clinical characteristic and differential diagnosis, reduce missed diagnosis and improve the early detection and treatment of Penicillium Marneffei infection, by means of this case report and literature review.
A patient hospitalized Penicillium Marneffei infection were presented here, together with 27 cases in the literature, among which 10 patients had complications of AIDS and 5 with other diseases.
Penicillium Marneffei is a temperature-sensitive, two-phase fungus, which can infect healthy and immunocompromised subjects. The common symptoms are lymphadenopathy and infection of the lung. The infection may be local or diffuse, involving the intestinal tract, soft tissue, bone, liver, spleen and bone marrow etc. The lesion can be classified into the granuloma type, suppurative type and anergy/necrosis type histologically. The yeast-like fungus were mainly found in the cytoplasm of macrophages, which were demonstrated by PAS and Giemsa staining. The wine red color developed on the culture confirms the diagnosis.
The diagnosis of Penicillium Marneffei infection should be considered when tuberculosis is suspected but not confirmed, and if the patient has a history of having lived or traveled in Southeast Asia, is anemic or resistant to anti-tuberculosis treatment. The major differential diagnosis is histoplasmosis. Early administration of anti-fungus drugs is essential for recovery.
No preview · Article · Jan 2005 · Zhonghua bing li xue za zhi Chinese journal of pathology
[Show abstract][Hide abstract] ABSTRACT: To investigate the mechanism of carbapenems resistance in Acinetobacter baumannii.
WHONET-5 software was used to analyze the trend of carbapenem resistance in Acinetobacter baumannii collected from 1999 to 2001 at Peking Union Medical College Hospital. Analytical isoelectric focusing was used to measure the pI of the beta-lactamase. Conjugation experiment was used to study the transfer of carbapenem resistance and plasmid DNA was extracted and purified with Qiagen Plasmid Mini Kit. The homology of the isolates was determined by pulsed field gel electrophoresis (PFGE). Integrase genes and blaIMP-, blaVIM-, blaOXA- genes for resistant isolates were amplified and sequenced.
Imipenem resistance in A. baumannii was ranged from 1.8%-8.5%, but only 9 resistant isolates were viable. They were co-resistant to other carbapenems, ceftazidime, aztreonam, and gentamicin, and four isolates were resistant to ciprofloxacin. Impipenem resistance could not be transferred to susceptible strains. No plasmid was extracted. Each isolate produced TEM-1, AmpC, and two enzymes (pI 6.7, 6.0), which can not be inhibited by cloxacillin and clavulanic acid. Each isolate had class I intergase gene. Nine isolates were all negative for PCR of blaIMP- and blaVIM- genes, but positive for blaOXA-23 specific PCR. Sequencing found 100% homology with blaOXA-23. PFGE found 3 clones (A type: 5 isolates; B type: 3 isolates; C type: 1 isolate). Control isolates (imipenem-susceptible, but ceftazidime, ciprofloxacin, and gentamicin resistant) were also A clone.
Production of OXA-23 carbapenemase in A. baumannii was one of the main mechanisms of carbapenems resistance at our hospital. It brings concern that imipenem-resistant clone has evoluted from nosocomial multiple-resistant strains.
No preview · Article · Nov 2003 · Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae