Objective To establish a diagnosis method for fungal infection using two-round PCR,and to evaluate its sensitivity in the detection of clinical specimens suspected to be infected with fungi.Methods A total of 29 specimens of clinical sputum and alveolar wash solution were collected from patients with suspicious fungal infection.All specimens uaderwent direct microscopy with 10%KOH,fungal culture,one-round PCR and two-round PCR.The fungal universal primer targeting ITS regions of rDNA was used in PCR.The detection rate for fungi was compared between these methods.Results The detection rate for fungi was 20.69%by direct microscopy,37.9%by fungal culture,17.2%by one-round PCR,and 48.3%by two-round PCR.More than one species of fungus were detected in 6.9%(2/29),3.4%(1/29)and 24.1%(7/29)of these specimens by fungal culture.one-round PCR and two-round PCR, respectively.There was a significant difference in the detection rate between two-and one-round PCR(x2=6.34,P＜0.05).With regard to the detection rate for more than one species of fungus,two-round PCR was significantly higher than one-round PCR and fungal culture(x2=4.09,6.30.bom P＜0.05).Conclusion Two-round PCR may help to improve the sensitivity of molecular diagnosis of fungus-infected specimens.

OBJECTIVE To investigate the epidemic situation of Acinetobacter in lower respiratory tract infection and their drug resistance,in order to provide evidence for clinical anti-infection therapy. METHODS The data of Acinetobacter from the sputum specimens of inpatients in our hospital with lower respiratory tract infection during 2006-2007 were collected and analyzed with the software the software WHONET5.4. RESULTS Among all pathogens in lower respiratory tract infection,Acinetobacter accounted for 9.2% in 2006 and 7.4% in 2007,the rate in deparment of neurosurgery,surgical ICU and respiratory ICU was higher. Acinetobacter had the highest susceptible rate to imipenem and were also susceptible to meropenem and cefoperazone/sulbactam. However,Acinetobacter had higher resistant rate to imipenem and meropenem while higher susceptible rate to cefoperazone/sulbactam in 2007 than in 2006. The susceptible rate of Acinetobacter to the third and forth generation cephalosporins,amikacin,levofloxacin and aztreonam was lower than 50%. CONCLUSIONS The drug resistance mechanism of Acinetobacter is so complicated that many kinds of drugs prove poorly effective. Carbopenems are recommended when single drug is utilized and drug combination based on the clinical and laboratory information can be tried.

OBJECTIVE To investigate the disinfectant and antibiotic resistance genotypes in 60 strains of Escherichia coli isolated from urine.METHODS Sixty strains of E.coli isolated from inpatients′ urine were collected from Jan 2006 to Oct 2008.Antibiotic susceptibility tests for fifteen antibiotics were performed by Kirby-Bauer method.And three kinds of disinfectant and antibiotic resistance genes(qacE△1,tehA,merA)were analyzed by polymerase chain reaction(PCR) and DNA sequencing.RESULTS More than 70.0% of the sixty strains of E.coli were susceptible to imipenem,piperacillin/tazobactam,cefoxitin,amikacin and gentamicin,and less than 50.0% were susceptible to the other ten antibiotics.There were 42 strains with qacE△1 gene(70.0%),10 strains with merA gene(16.7%) and all strains with tehA gene.The sequence of the first strain was different from those reported in GenBank,so it was a new subtype.CONCLUSIONS There are 70% of E.coli strains isolated from urine samples with qacE△1 gene.And disinfectant resistance may be one of the main factors for hospital infection in the future.

Objective To determine the potential impact of superantigens produced by skin-colonizing Staphyiococcus aureus in patients with atopic dermatitis and eczema. Methods Of 117 patients with atopic dermatitis and 199 with eczema, 140 Staphyiococcus aureus strains were isolated from the skin specimens. Superantigens were detected with reverse passive latex agglutination. Results Among 140 Staphyiococcus aureus strains, 60 (42.9%) produced superantigens, among which 43 produced one kind of superantigens only and 17 produced at least two kinds. Of strains isolated from atopic dermatitis, 51.5% produced superantigens and no significant difference was seen in superantigen production between lesional and non-lesional strains in atopic dermatitis. Of strains isolated from eczema patients, 34.7% (all were lesional strains) produced superantigens. The positive rates of total superantigens, lesional superantigens and toxic shock syndrome toxin-1 production were all higher in the strains from atopic dermatitis than in those from eczema. Conclusions Superantigen production by skin-colonizing Staphyiococcus aureus probably plays a more important role in atopic dermatitis than that in eczema. However, further studies are necessary to validate its importance.

n positive blood culture, and they are resistant to a variety of antimicrobial agents, which should be called attention.

Objective To report a case of vaginal colonization due to Trichosporon inkin. Methods A 34-year-old female presented with increased vaginal discharge accompanied by abnormal odor for 2 months. Clinical laboratory examination was carried out. Cultures of vaginal discharge yielded yeast-like colony. Subsequently, the isolate underwent the following mycological examinations: purification, slide micro-culture, temperature test, urea enzyme test, biochemistry identification, antifungal susceptibility test, and gene sequencing. Results Gynecological examination revealed white homogeneous secretions attached to mucous membrane of the vagina. Nugent scores of vaginal discharge amounted to 5-6. Two rounds of culture of vaginal discharge resulted in stramineous, reductus and yeast-like colony. The isolate could grow in 42 ℃. Appressorium on the top of hypha and typical sarcinae formed in slide microculture of corn agar, and yeast malt agar was the optimal growth medium for it. Urea enzyme test was positive. API 20C AUX biochemical test and gene sequencing revealed that the isolate was consistent with Trichosporon inkin. The isolate was sensitive to amphotericin B and azoles such as clotrimazole and fluconazole, but resistant to flucytosine and caspofungin. Conclusions It is the first report of vaginal colonization due to T. Inkin in China. The accu-rate identification of T. Inkin relies on synthetic analysis of phenotype characteristics, biochemistry test and molecular sequencing.

Objective To investigate the mechanism of quinolone resistance in Psendomonas aeruginosa.Methods The minimum inhibitory concentrations (MICs)of ciprofloxacin and levofloxacin with and without carbonylcyainde-m-chlorophenylhydrazone(CCCP)were determined by agar dilution method.Polymerase chain reaction(PCR)and DNA sequencing were used to study the mutations in quinolone resistance-determining region of gyrA and parC genes.The strains were genotyped by enterbacterial repetitive intergenie consensus-PCR(ERIC-PCR).Results Sixteen quinolones-resistant Pseudomonas aeruginosa strains were obtained.The MICs of ciprofloxacin and levofloxacin were not reduced significantly by adding CCCP.Thr-83→Ile of gyrA and Ser-87→Leu of parC were found simultaneously in 16 strains of resistant Pseudomonas aeruginosa.Analysis of ERIC-PCR products indicated that 16 quinolone-resistant strains had an identical band pattern which was different from that seen in the sensitive strains.Conclusion Mutations in gyrA and parC may be the main mechanism of quinolone resistance in clinical isolates of Pseudomonas aeruginosa.

Objective To investigate the pathogen distribution and susceptibility profile of fungal isolates from bloodstream infections,and valuate the clinical utility of G test in diagnosis of fungal infections for the purpose to improve antifungal therapy.Methods A retrospective analysis was carried out to analyze the fungal pathogens isolated from bloodstream infections in the First Affiliated Hospital of Nanjing Medical University during the period from January 2013 through December 2015 and their antimicrobial susceptibility.Results A total of 114 fungal strains were isolated from bloodstream infections during the 3-year period,most of which were Candida (99/114,86.8％),especially Candida albicans (30.7％).About 41.2％ (47/114) of the fungal strains were isolated from Department of Thoracic Surgery (10,5 and 4 strains in 2013,2014 and 2015),Hematology (11 strains in 2014),and ICU (7 strains in 2014).Antimicrobial susceptibility testing showed that all the fungal strains (100％) were susceptible to amphotericin B,but 83.5％ susceptible to itraconazole (the lowest).G test was positive before the result of blood culture in 13 of the 54 patients who received G test.Conclusions Candida was the most common fungus in fungal bloodstream infection.Amphotericin B is the most active antifungal agent in vitro.Blood culture combined with serological test can provide clinicians an earlier and reliable diagnosis.

Objective To observe the formation of Staphylococcus aureus biofilm and the inhibitory and dispersive effects of betaine on the biofilm.Methods The inhibitory and dispersive effects of 0.1％ betaine on the biofilm from 20 strains of Staphylococcus aureus were examined by crystal violet assay.Results All the 20 strains of Staphylococcus aureus formed biofilm.The biofilm of methicillinsensitive Staphylococcus aureus (MSSA) was formed in 24 hours with peak value of absorbance (A590 nm) (1.99 ± 0.53).The biofilm of methicillin-resistant Staphylococcus atureus(MRSA) was formed in 48 hours with peak value of absorbance(A590 nm) (1.13 ±0.47).After adding betaine,the absorbance(A590 nm) of MSSA biofilm fell down to(1.74 ± 0.61) in 24 hours,while the absorbance(A590 nm) of MRSA biofilm fell down to(0.40 ± 0.12) in 48 hours,which was significantly reduced compared with the controls (t =2.43,5.84,P ＜ 0.05 respectively).When adding betaine after the biofilm formed,the absorbancies (A590 nm) of both MSSA and MRSA showed no significant difference compared with the controls (P ＞ 0.05).Conclusion Betaine could inhibit biofilm formation of Staphylococcus aureus at concentration of 0.1％,but it could not disperse the mature biofilm of Staphylococcus aureus.

Objective To investigate the distribution and antimicrobial resistance profile of clinical gram-negative bacterial isolates in the First Afifliated Hospital of Nanjing Medical University during 2014.Methods Bacteria identiifcation was performed by API system or the VITEK-2 Compact automatic identiifcation system. Disk diffusion susceptibility testing or VITEK-2 Compact automatic identification system was used to determine the susceptibility to antimicrobial agents. All data were analyzed using WHONET 5.6 software.Results Among the total 7 931 clinical isolates in 2014, gram-negative bacteria accounted for 64.2% (5 088/7 931). The top three pathogens wereE. coli,A. baumannii andK. pneumoniae. Notably, during the year 2014, 195 strains of carbapenem-resistantEnterobacteriaceaewere isolated, about 6.9% of all theEnterobacteriaceae isolates. Meanwhile, 613 (66.5%) strains of multiple drug resistantA. baumannii and 197 (28.7%) strains of multiple drug resistantP. aeruginosa were isolated.Conclusion During the year 2014, the resistance of the gram-negative bacteria in this hospital is mainly characterized by carbapenem-resistantEnterobacteriaceae, multiple drug resistant A. baumanniiand multiple drug resistantP. aeruginosa. Surveillance of antimicrobial resistance is beneifcial for rational use of antibiotics.