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Objective:To retrospectively analyze the clinical characteristics and drug resistance among COVID-19 patients with bacterial and fungal infections.Methods:Clinical data of COVID-19 patients whose blood, urine, sputum and alveolar lavage fluid samples were positive for bacteria and fungi were collected in Tongji Hospital from February 10 to March 31, 2020. WHONET5.6 software was used to analyze drug susceptibility test results.Results:A total of 95 COVID-19 patients positive for pathogenic bacteria were enrolled and among them, 23 were non-critical patients and 72 were critical patients. The main symptoms in these patients included fever, cough with sputum, fatigue and dyspnea. Male and female critical patients accounted for 63.89% and 36.11%, respectively. Most of the patients with bacterial and fungal infections were critical type, accounting for 23.61%. The mortality rates of non-critical and critical patients were 13.04% and 61.11%, respectively. A total of 179 strains of pathogenic bacteria were isolated. The positive rate of Escherichia coli in non-critical patients was 37.50%, which was higher than that in critical patients. However, the positive rates of Acinetobacter baumannii and Klebsiella pneumoniae in critical patients were both 29.87%, higher than those in non-critical patients. There was no significant difference in the positive rate of gram-positive bacteria or fungi between non-critical and critical patients. It was noteworthy that the positive rate of Candida parapsilosis in blood samples of critical patients was relatively high, reaching 36.40%. Drug susceptibility test results showed that no carbapenem-resistant Escherichia coli stains were detected and 60.87% of Klebsiella pneumoniae strains were resistant to carbapenems. Acinetobacter baumannii strains were 100% resistant to three antimicrobial drugs. Methicillin-resistant Staphylococcus aureus strains accounted for 71.43%, but no vancomycin-resistant gram-positive cocci were found. Conclusions:Critical COVID-19 patients were mostly male and prone to multiple bacterial and fungal infections. The mortality of critical patients was higher than that of non-critical patients. Critical COVID-19 was often complicated by hospital acquired infections caused by bacteria including Acinetobacter baumannii and Klebsiella pneumoniae with high drug resistance.
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Objective To learn the distribution, epidemiology and antimicrobial susceptibility of diarrheagenic Escherichia coli (DEC) isolated from patients with acute diarrhea among children less than 5 years old. Methods Totally 684 stool samples collected from Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology between August 1, 2015 and September 30, 2016 were tested by culture and identified the common pathogens. PCR was applied to detect the virulence genes of DEC. Meanwhile, serotyping of enteropathogenic E. coli (EPEC) was performed by slide agglutination tests for all the isolates of EPEC. An antimicrobial sensitivity test was performed using the agar dilution method. Results A total of 149 (21.7％) enteric bacteria pathogens were isolated from 684 specimens. DEC was found in 54 cases, ranked 2nd among the pathogenic bacteria. DEC tended to occur in summer/autumn periods. EPEC was the most frequent DEC genotype, accounted for 50％ (27/54). Among EPEC, atypical EPEC was dominant, accounted for 77.8％ (21/27) and typical EPEC only accounted for 22.2％ (6/27). Followed by enteroaggregative E. coli 20.4％(11/54), enterotoxigenic E. coli 14.8％(8/54), enteroinvasive E. coli and Shiga toxin-producing E. coli 3.7％(2/54), 7.4％(4/54) cases were co-infected with more than one DEC genotypes. About 17/18 of suspicious DEC isolates can get the same genotypes by commercial multiplex PCR kit and single PCR test. Among the 27 EPEC strains, only 11(40.7％) strains can be detected by the slide agglutination serotyping method. More than 50％ (27/54) of DEC isolates were resistant to conventional first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole) and cefazolin, cefuroxime, cefotaxime, but relatively low resistance to cefoxitin, amikacin, piperacillin/tazobactam, imipenem and meropenem. However, there was still a 9.2％ (5/54) resistance rate to carbapenems. Conclusions DEC strains exhibited a high frequency of resistance to many antibiotics. Empirical antimicrobial therapy of severe DEC infection faces the challenge from the high resistance to ampicillin, trimethoprim-sulfamethoxazole. Even worse, some strains were resistant to relatively efficient drugs imipenem and meropenem. It is necessary to strengthen the epidemiological survey and antimicrobial resistance of DEC.
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Objective To investigate the changes of plasma protein Z and coagulation factor Ⅷ activity in children with primary nephrotic syndrome.Methods 94 children with primary nephrotic syndrome were se-lected as the observation group,and 63 healthy children were selected as the control group.The blood samples of peripheral blood were collected from the study group,and plasma protein Z and coagulation factor Ⅷ were measured by enzyme linked immunosorbent assay.Enzyme linked immunosorbent assay was used to measure plasma protein Z and coagulation factor Ⅷ.The changes of plasma protein Z and coagulation factor Ⅷ in the two groups were compared,and the changes of plasma protein Z and coagulation factor Ⅷ in the acute and re-covery phase,and the correlation between plasma protein Z and coagulation factor Ⅷ were observed.Results The observation group of plasma protein Z level is lower than the control group,blood coagulation factor Ⅷlevels higher than the control group,and the difference was statistically significant(P<0.05);plasma protein Z level in acute stage is lower than the recovery period,and coagulation factor Ⅷ level is higher than the recov-ery period,the differences were statistically significant(P<0.05);plasma protein Z and coagulation factor Ⅷwas negatively correlated.Conclusion The plasma protein Z level in children with primary nephrotic syn-drome is significantly reduced,and the activity of coagulation factor Ⅷ is significantly increased.Detection of plasma protein Z and coagulation factor Ⅷ level can predict primary nephrotic syndrome in children.
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Objective To evaluate the risk clinic factors of severe community-acquired pneumonia in older adults,and to provide examples for its clinic application.Methods Sixty-four case patients who were admitted for a diagnosis of severe community-acquired pneumonia in older adults in Beijing Haidian Hospital from January 2013 to July 2015 were selected as observation group.One hundred cases patients also admitted for a diagnosis of community-acquired pneumonia were selected as control group.Within 24 h of admission,the clinical data were collected,medical history were collected,and the serum biochemistry,coagulation index fibrin degradation product,D-dimer and inflammatory factor procalcitonin were detected.The data were analyzed by univariate analysis,and logistic regression analysis was used to analyze the variables with significant difference in single factor analysis.Results Single factor analysis showed that the percentage of severe pneumonia with central nervous system disorders,severe pneumonia with aspiration,severe pneumonia with two or more comorbidities,aspiration and severe pneumonia with bedridden patient in observation group were obviously higher than the control group,the difference between two groups have remarkable statistical significance((82.21％ (53/64) vs.32％(32/100),60.93％(39/64) vs.1％(1/100),(84.37％,54/64) vs.54％(54/100),90.62％(58/ 64) vs.28％ (28/100),59.37％ (38/64) vs.11％ (11/100);P＜0.01 or P＜0.05).The mortality of observation group was higher than the control group,the difference between two groups have remarkable statistical significance(56.62％ (36/64)] vs.3％ (3/100),P=0.001).Albumin of severe pneumonia was obviously lower than the control group,the difference between two groups have remarkable statistical significance ((27.79 ±8.53) g/L vs.(33.66±9.63) g/L,P=0.011).Fibrin degradation product of severe pneumonia was obviously lower than the control group,the difference between two groups have remarkable statistical significance ((i0.98 ± ± 1.32) ng/L vs.(3.61±0.98) ng/L,P=0.002).D-dimer of severe pneumonia was obviously higher than the control group,the difference between two groups have remarkable statistical significance ((2.68± 0.56) mg/L vs.(0.42±0.12) mg/L,P=0.001).Procalcitonin of severe pneumonia was obviously higher than the control group,the difference between two groups have remarkable statistical significance ((1.63±0.32) ng/L vs.(0.13 ± ±0.21) ng/L,P =0.015).The result of multiple factors logistic regression analysis showed the aspiration,hypoproteinemia,D-dimer were severe community-acquired pneumonia in older adults's independent risks (OR =1.782,1.208,1.356,P＜0.05).Conclusion Aspiration,hypoproteinemia,D-dimer are the factors of risking suffering severe community-acquired pneumonia in older adults.D-dimer could be the detection index of severe community-acquired pneumonia in older adults.
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Objective To explore the inhibitory effect of 24 pseudomonas aeruginosa(PA) on pathogenic fungi ,such as candida albicans ,candida tropicalis ,candida glabrata ,candida parapsilosis ,candida krusei ,mucous spore bacterium (MSB) etc .Methods 24 PA isolates were collected from clinical specimens and identified by Gram′s stain ,oxidase production and the API 20NE system(bi-oMerieux ,France) .Cross-streaking method and sterilizing filter paper-disk method and co-cultured method were applied to observe the inhibitory effect of PA .Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analyzed the difference of bacte-rial proteins of PA .Results The results showed that some strains of 24 PA had strong inhibitory effect against pathogenic fungi , some strain had partial effect and others had no effect .Co-cultured test showed that PA could inhibit the growth of fungal hyphae . SDS-PAGE displayed the significant difference in secretive proteins between the PA strains which had strong effect and no effect . Conclusion PA have inhibitory effect upon common pathogenic fungi and and this might be related to inhibit fungal hyphae forma-tion ,various protein secretion and inhibit the growth of fungi .
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In order to obtain a virus-like particle vaccine both for porcine parvovirus (PPV) prevention and growth-promotion, VP2 gene of PPV NJ-a strain was amplified with PCR, and four copies of synthetic somatostatin gene were fused to the N-terminal of VP2 gene. The fused gene was cloned into pFast-HT A to construct the recombinant plasmid pFast-SS4-VP2, then the pFast-SS4-VP2 was transformed into DH10Bac competent cells and recombined with shuttle vector Bacmid, followed by identification with blue-white screening and PCR analysis for three cycles, and the positive recombinant was named as rBacmid-SS4-VP2. The positive Sf-9 cells were transfected with rBacmid-SS4-VP2 by Lipofectamine to produce recombinant baculovirus. When the cytopathic effect (CPE) was obvious, the transfected Sf-9 cell was harvested, and the positive recombinant virus was named as rBac-SS4-VP2. The insertion for the target gene into baculovirus genome was confirmed with PCR. SDS-PAGE and Western blotting revealed that the calculated protein of approximately 68 kDa was in the expressed in the insect cells. The Sf-9 cells infected with rBac-SS4-VP2 were stained positive against PPV antibody using the indirect immunofluorescence assay (IFA). Moreover, the virus particle self-assembly was observed under electron microscopy. 90 four-week-old mice were immunized by the recombinant protein coupled with different adjuvants alhydrogel, IMS and oil. VP2-specific ELISA antibodies, PPV-specific neutralizing antibody, somatostatin antibody and growth hormone levels were examined to evaluate the immunogenicity of this virus like particle. Results indicated that mice groups immunized rSS4-VP2 protein with alhydrogel and IMS developed similar humoral immune response comparing with inactived PPV vaccine. Mice group immunized with rSS4-VP2 generated higher level of SS antibody and growth hormone comparing with negative control, mice receiving rSS4-VP2 with alhydrogel developed the highest antibody titre than all other groups, while the oil group developed the lowest antibody level. This study provides not only a new rout for production of safe and effective virus like particle subunit vaccine, but also the foundations for peptide presentation and multivalent subunit vaccine design.