Objective: To investigate the characteristics of hemolysis, resistance and homology of Staphylococcus cohnii urealyticum. Methods: A retrospective study was carried out on thirteen clinical strains of Staphylococcus cohnii urealyticum. They were re-identified by MALDI-TOF MS. Their colony and hemolytic characteristics on blood agar plates were observed. The co-hemolysis between Staphylococcus cohnii urealyticum and Staphylococcus aureus was demonstrated. The hemolysin genes and drug resistance genes were detected by PCR. Pulsed field gel electrophoresis and mass spectrometry were used to analyze the homology of strains. The susceptibility of strains to antimicrobial agents was detected by agar dilution. Results: The confirmed 13 strains of Staphylococcus cohnii urealyticum showed various levels of hemolysis and had enhanced synergistic hemolysis with Staphylococcus aureus. All strains were susceptible to vancomycin and tigecycline. There were 12 strains which carried mecA gene, 7 strains carried cfr gene, 7 strains carried ermC gene. The 13 strains were divided into 3 groups by MALDI-TOF MS, and 6 types by pulsed field gel electrophoresis. Conclusions Clinical strains of Staphylococcus cohnii urealyticum demonstrated various levels of hemolysis which could be enhanced by Staphylococcus aureus. Although they carried different drug resistance genes, they were all susceptible to vancomycin and tigecycline.

Objective: To understand the in vitro growth characteristics of Cryptococcus gattii VGⅠ and VGⅡ isolated in China and the diversity in their virulence to Galleria mellonella. Methods: Based on the results of multilocus sequence typing for eight strains of Cryptococcus gattii isolated in China, the strains were cultured in vitro to draw growth curves, observe the melanin production and measure the capsule thickness. The median lethal time (LT₅₀) and median lethal dose (LC₅₀) at 48 h of Cryptococcus gattii were calculated using Galleria mellonella infection test. Fourteen strains of Cryptococcus neoformans were studied for comparison. Results: The eight Cryptococcus gattii strains were six VGⅠ and two VGⅡ. The growth curves of Cryptococcus gattii VGⅠ and VGⅡ were similar to that of Cryptococcus neoformans when culture at 30℃. The total number for each of them could reach 10⁸ CFU/ml at 96 h under 30℃. However, the total number at any time point at 37℃ was less than that at 30℃. There was no significant difference in the amount of melanin produced by Cryptococcus neoformans under 30℃ and 37℃, but both VGⅠand VGⅡ types of Cryptococcus gattii could produce more amount of melanin under 37℃ than under 30℃. The ratio of capsule/cell wall diameter of Cryptococcus gattii VGⅠwas greater at 37℃ than that at 30℃ with statistical significance (P<0.001). Cryptococcus neoformans showed the longest LT₅₀, followed by VGⅠand VGⅡ types of Cryptococcus gattii. The LT₅₀ of Cryptococcus gattii VGⅡ at the concentration of 1×10⁶ CFU/ml was 72 h, and its LC₅₀ at 48 h was 1×10⁸ CFU/ml. Conclusions Like Cryptococcus neoformans, Cryptococcus gattii VGⅠ and VGⅡ grew faster under 30℃ than under 37℃, but more melanin was produced and thicker capsule was formed under 37℃ than under 30℃. Among Cryptococcus neoformans and VGⅠ and VGⅡ types of Cryptococcus gattii, Cryptococcus gattii VGⅡ showed the shortest LT₅₀ and the strongest virulence to Galleria mellonella.

Hypervirulent Klebsiella pneumoniae ( hvKP) mainly infects healthy people and causes serious infections, such as liver abscess, meningitis, necrotizing fasciitis, endophthalmitis and severe pneu-monia. Studies have shown that hvKP is more virulent than classic Klebsiella pneumoniae characterized by ex-pressing more capsular polysaccharide and carrying the virulence factors including magA, rmpA and iron ac-quisition molecules. The greater survival and anti-phagocytosis abilities of hvKP strains contribute to the spread and metastasis of hvKP infection. This review describes the virulence factors, colonization and infec-tion of hvKP as well as the host immunity to hvKP.

Objective To study the education of medical mycology for undergraduates of medical laboratory specialty and provide a basis for teaching reformation.Method Setting of mycology related courses of medical mycology for undergraduates in 5 medical schools and 85 inspection and technical personnel's detection of fungi in 81 hospitals were investigated through consultation and questionnaire survey.Results More than 140 class hours for medical mycology were arranged in 5 schools,but as to medical mycology,22 class hours in 1 school and less than 10 class hours in 4 schools,the minimum class hours were 5.Although various numbers of Candida and filamentous fungi could be isolated in hospitals investigated,more than half laboratory workers could not identify penicillium,thermally dimorphic fungi,Zygomycetes and Dematiaceous fungi.Conclusion Education on medical mycology for medical laboratory specialty undergraduates is insufficient and the corresponding teaching lacks such content as medically important pathogenic fungi detection methods and identification characteristics.The hospital technical personnel's fungal identification ability cannot meet the situation of increasing fungal infection involved in clinical medicine,so it is necessary to carry out teaching reformation of medical mycology for undergraduates in laboratory medicine,including adding class hours,increasing course contents and so on.

Objective To detect the hypermucoviscosity phenotype , capsular serotype and virulence gene of Klebsiella pneumonia (K.pneumonia) from various kinds of clinical specimens and understand the characteristics of different K.pneumonia causing infections.Methods A retrospective study was conducted through collection of 178 K.pneumonia isolates from blood, sputum, bronchoalveolar lavage fluid , urine, normally sterilized fluid , puncture fluid from liver abscess and other abscesses between January 2010 and December 2012 in General Hospital of Chinese PLA.String test was carried out for detection of hypermucoviscosity phenotype.Capsular serotype and virulence gene ( rmpA) were checked by polymerase chain reaction.Analysis was made according to the hypermucoviscosity , capsular serotype , rmpA gene , as well as the sources of K.pneumoniae.Statistic data was analyzed by contingency table analysis and χ2 test.Results Eighty-three out of 178 ( 46.6%) strains of K.pneumonia were hypermucoviscous with positive string test, the positive rate of virulence gene rmpA was 92.8%(77/83).K1/K2/K57 capsular serotypes were the predominant serotypes in the group of puncture fluid from liver abscess and other abscesses (75.0%,27/36)than the group of blood (32.4%,12/37), urine(21.7%,5/23) and normally sterilized fluid(25.0%,5/20), and also more than in the group of sputum , bronchoalveolar lavage fluid (50.0%,22/44),χ2 =21.19,P<0.01.The positive rate of string test in the group of puncture fluid from liver abscess and other abscesses (77.8%, 28/36)was significantly higher than the group of blood (29.7%, 11/37), urine (30.4%, 7/23), or normally sterilized fluid (25.0%, 5/20),χ2 =27.90,P<0.01.The positive rate of rmpA gene in the isolates from puncture fluid of liver abscess and other abscesses was higher than other groups.Conclusions As the pathogens of various kinds of infections , mainly abscess and respiratory infection, hypermucoviscous strains of K.pneumonia were of great clinical significance.Capsular serotype K57, as well as K1 and K2, possessed hypermucoviscosity and hypervirulence in China.

Objective To detect the main virulence genes and biofilm formation of Enterococci strains isolated from blood samples .Methods Twenty-eight strains of Enterococcus faecalis ( E.faecalis) and 54 strains of Enterococcus faecium ( E.faecium) were collected from blood samples .Five main virulence genes (asa1, esp, hyl, cylA and gelE) were detected by multiplex PCR.Biofilm formation was investigated by using microtiter dish biofilm formation assay .Results All E.faecalis strains were positive for at least one kind of virulence genes , of which 14 strains were concurrently positive for asa1, esp, cylA and gelE.asa1, cylA and gelE were only detected in E.faecalis strains, while hyl gene only existed in E.faecium strains. Twenty-seven strains of E.faecium were esp positive, of which 12 strains were both hyl and esp positive. None of the 5 virulence genes were identified in 10 strains of E.faecium.85.7% of E.faecalis strains and 63.0%of E.faecium strains could form biofilm.Conclusion Compared with E.faecium strains, more types of virulence genes were detected in E.faecalis strains with higher positive rates .Moreover , E.faecalis strains were more likely to form biofilms than E.faecium strains.

ObjectiveTo evaluate the application value of the quantitative procalcitonin (PCT) test in bloodstream infection.Methods Of 1066 patients with blood culture and PCT detection were collected in our hospital,retrospectively,1010 were effective cases.The relationship between blood culture results and serum PCT levels was investigated.PCT levels in gram-negative bacterial infection,gram-positive bacterial infection and candidiasis were compared.The prognosis of 33 blood culture positive patients with repeated PCT detection results were analyzed.Mann-Whitney U test was used to compare the PCT value among the three groups,and Fisher' s test was used to compare the death rate among the three groups.ResultsIn the patients with negative blood culture results,the median of PCT was 0.37 (0.11 - 1.67) μg/L.But in the patients with positive blood culture results,the median of PCT were 2.24(0.57 -11.59) μg/L The positive rate of PCT in gram-negative bacteria infection,gram-positive bacterial infection and candidiasis were 86.6％,72.0％ and 75.7％,respectively.In the 33 patients subjected to repeated PCT detections,the mortality of the patients with decreasing PCT was lower than the others.The patients whose PCT levels were greater than 5 μg/L had poor prognosis.ConclusionsQuantitative PCT is proved to be an effective method for rapid diagnosis of bloodstream infection.The changing trends of PCT test results has certain reference value for the patients' prognosis.

ObjectiveTo establish the rapid molecular diagnosis of 16 common coagulase negative Staphylococcus(CNS).MethodsDNA sequencing of 16 CNS would be obtained with gap gene.After the alignment gap gene sequences which were available in the GenBank,the bacteria were identified with homological alignment and phylogenetic tree,and compared with the 16S rRNA gene.ResultsThe sequence similarity of the gap sequences ranged from 39% to 98% in 16 CNS.There were the highest similarity (98%) between S.hominis and S.hominis subsp,and the lowest(39% ) between S.saprophyticus and S.xylosus.The sequence similarity of the 16S rRNA sequences ranged from 96 to 98%,at least two species of bacteria similar rate of 99% and the most four species similar rate of 99%.Phylogenetic homology analysis showed that it was a high confidence(99% ) in the detection ofS.xylosus and S.lentus,S.chromogenes and S.intermedius,S.hominis and S.hominis subsp,but for 10 other species of bacteria,gap homology analysis has less unreliable confidence(49%,56% ) and 16S rRNA has more unreliable confidence(43%,43%,50%,56%,63%,65%,76% ).ConclusionAnalysis of gap sequence could identify 16 CNS timely and accurately,with higher confidence than 16S rRNA.

OBJECTIVE To investigate the prevalence of DHA AmpC ?-lactamases mediated by plasmid in Klebsiella pneumoniae in China.METHODS Antimicrobial susceptibility test was conducted by the methods of double agar dilution and ESBLs confirmatory in K-B method according to the criteria of guidelines of CLSI.AmpC ?-lactamases were detected on the basis that AmpC ?-lactamases could be inhibited by 3-aminophenylboronic acid(APB).Gene chip technology and PCR were used to detect ESBLs and AmpC gene.RESULTS Among total 34 isolates of K.pneumoniae 32(94.1%) produced AmpC ?-lactamases and ESBLs.The most common(38.3%) were types DHA and TEM and SHV.MIC50 and MIC90 of all strains to all tested antimicrobial agents were lower than 34 strains tested 0.25?g/ml and 0.5?g/ml.Fourteen strains AmpC and ESBLs were conjugated successfully.CONCLUSIONS DHA AmpC ?-lactamases mediated by plasmid are the most common in K.pneumoniae in General Hospital of PLA of China.The most common(38.3%) are types DHA and TEM and SHV.Fourteen(41.2%) strains can be spreaded by plasmid.

OBJECTIVE To investigate the phenotype and genotype of plasmid-encoded AmpC and extended spectrum beta-lactamases in Klebsiella pneumoniae.METHODS 3-Aminophenylboronic acid(APB) test and ESBLs confirmatory test were used for phenotypic detection of AmpC and ESBLs.Conjugation was conducted in order to understand the spread of plasmid in bacteria.The size and genotype of ampC and ESBL genes were studied by extraction and purification of plasmid,PCR and sequencing analysis.RESULTS A plasmid of about 15kb was extracted from K.pneumoniae.This plasmid carrying resistance genes to antibiotics could be spread from K.pneumoniae to recipient Escherichia coli NK5449 through conjugation.DHA-type ampC gene and SHV-type ESBLs gene could be amplified from plasmids extracted from both K.pneumoniae and its conjugant in E.coli,they were DHA-1 ampC gene and SHV-12 ESBLs gene confirmed by sequencing analysis.CONCLUSIONS DHA-1 ampC gene and SHV-12 ESBLs gene are detected from the plasmid of K.pneumoniae.