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Objective: To observe the dynamic changes of serum cryptococcal capsular polysaccharide antigen (CrAg) titer and chest CT of pulmonary cryptococcosis (PC) after antifungal therapy. Methods: A retrospective study was performed for patients with PC admitted to the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from January 2015 to April 2018. Serum CrAg titers and Chest CT examination were performed for all the cases before and after treatment. The difference between immunocompetent hosts group and immunocompromised hosts group were compared and analyzed. Results: Eighty-two patients with PC including 46 male (56.1%) and 36 (43.9%) female were enrolled. Fifty-two (63.4%) patients were proven PC and thirty (36.6%) patients were probable PC. Forty-five (54.9%) patients had underlying diseases. Fifty-four (65.9%) patients were immunocompetent hosts and twenty-eight (34.1%) patients were immunocompromised hosts. The mean duration of treatment was (7.9±2.4) months and the mean follow-up was (24.0±10.0) months. Improvement (≥75%) in chest CT were found in 64.8% of the cases in immunocompetent group and 67.9% in immunocompromised group after 6 months' treatment. Improvement (≥75%) was found in 88.9% of the cases with patchy infiltrates or consolidation and only 63.0% in nodular or mass-like type and mixed patterns of PC. The serum CrAg titer of 55 cases ranged from 1∶4 to 1∶160 before treatment (median 1∶40) and decreased for all cases after treatment. The serum CrAg titer became negative in 20 cases at last. Mean time of serum CrAg titer turning negative was (11.8±8.1) months. The serum CrAg titer became negative or decreased to 1∶1 in 24 cases after treatment cessation, of whom the serum CrAg titer ranged from 1∶5 to 1∶160 before treatment (median 1∶20). The serum CrAg titer of 31 cases ranged from 1∶4 to 1∶640 before treatment (median 1∶64), of whom the serum CrAg detections were still positive after treatment cessation, and CrAg titer was 1∶10 (ranged from 1∶2 to 1∶160). Conclusions: In PC, chest CT improves after antifungal treatment, and the infiltrates or consolidation type of PC resolves faster than nodular or mass-like shadows and mixed patterns in CT. The serum CrAg titer decreases after antifungal treatment.

Objective: To construct the KbvR gene of LuxR family deletion mutant and complementation strains from Klebsiella pneumoniae NTUH-K2044 and analyze the effect of KbvR on bacterial growth, biofilm formation and capsular synthesis., Methods: A KbvR gene deletion mutant strain was constructed using the suicide vector pKO3-Km, and the gene fragment including KbvR coding region, promoter area and transcription termination area were amplified and cloned into pGEM-T-easy plasmid to construct KbvR complementation strain. The growth curves of the wild-type strain, KbvR gene deletion mutant strain and complementation strain were observed to assess the effect of KbvR on bacterial growth. Crystal violet staining method was used to measure the effect of KbvR on biofilm formation; the effect of KbvR on capsular synthesis was detected using string test, centrifugal test and RT-PCR., Results: The KbvR deletion mutant and complementation strains were constructed successfully. KbvR gene did not affect the growth of the bacteria, but biofilm formation and capsular synthesis were attenuated in KbvR deletion mutant strain., Conclusion: As a transcription factor of the LuxR family orphans of the quorum sensing system, KbvR positively regulates bacterial biofilm formation by affecting capsular synthesis.

Objective: To analyze the occurrence feature of adverse events following immunization (AEFI) of Hib conjugate vaccine (HibCV) and to evaluate the safety of HibCV in postmarketing., Methods: 2008-2013 HibCV AEFI data were collected through national AEFI information management system, which were downloaded in March 18, 2014.The demographic information and inoculation quantity of HibCV were from Immunization information management system in Jiangsu province. The incidence rate and 95% CI value of AEFI, common vaccine reaction and rare vaccine reaction following immunization of HibCV were calculated. The differences in the incidence rate of common vaccine reaction and rare vaccine reaction among sex, months of age, and number of injections were compared by means of (χ² tests., Results: A total of 6.16 million doses of vaccine were administered in Jiangsu province during 2008-2013, and 4 718 vaccinees reported having adverse event, for a rate of 76.60/100 000 (95% CI: 74.42/100 000-78.79/100 000). The incidence rate of common vaccine reaction and rare vaccine reaction was 71.10/100 000 (95% CI: 68.99/100 000-73.20/100 000) and 5.16/100 000 (95% CI: 4.60/100 000-5.73/100 000), respectively. The main symptoms of common vaccine reactions were fever, swelling, indurations and gastrointestinal reactions. The incidence rates of them were 40.54/100 000, 35.09/100 000, 12.94/100 000 and 0.36/100 000 in turn. The main symptoms of rare vaccine reactions were anaphylactic rashes and angioedema, the incidence rates of which were 4.77/100 000 and 0.15/100 000 respectively. 91.39% (4 002/4 379) of common vaccine reactions and 88.36% (281/318) of rare vaccine reactions happened within 1 d after vaccination. Anaphylactic shock (3 cases) and laryngeal edema (1 case) all happened within 1 d after vaccination. The incidence rate of common vaccine reactions among boys (79.72/100 000, 2 641/3 313 071) was higher than that of girls (61.07/100 000, 1 738/2 846 001) (χ² = 74.92, P < 0.001). The incidence rate of common vaccine reactions among children aged ≥ 12 month-old (86.82/100 000, 2 200/2 533 949) was higher than that among children aged 2-11 month-old (60.11/100 000, 2 179/3 625 123) (χ² = 149.79, P < 0.001). The incidence rate of common vaccine reactions in children vaccinated the first dose (78.93/100 000, 2 666/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (61.59/100 000, 1 713/2 781 458) (χ² = 64.59, P < 0.001). The incidence rate of rare vaccine reactions in children vaccinated the first dose (6.69/100 000, 226/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (3.31/100 000, 92/2 781 458) (χ² = 33.82, P < 0.001)., Conclusion: The safety of HibCV among children was relative good. However, the surveillance should still focus on the anaphylactoid reactions of anaphylactic shock and laryngeal edema after HibCV immunization.

Objective: To compare the safety of haemophilus influenzae type b (Hib) vaccine vaccination on vastus lateralis muscle and deltoid muscle of infant., Methods: A total of 408 3-4 months old infants were divided into vastus lateralis muscle group and deltoid muscle group in Beijing, 2014. They were divided into the vastus lateralis muscle group (204) and deltoid muscle group (204) by extracting random number. Each observation object was given 3 doses of Hib vaccine according to the program. Collected systemic and local reactions after vaccination and calculated the incidence of adverse reactions., Results: A total of 61 infants were quitted during the study, 1 132 doses were observed. The total reactions incidence of Vastus lateralis muscle group and Deltoid muscle group were 33.0% (186/564) and 27.6% (157/568) with no statistical differences (χ² = 3.818, P = 0.059). The two groups incidence at the same day of vaccination (day 0) which the highest were 23.2% (131/564) and 20.6% (117/568), then declined with time (linear trend test vastus lateralis muscle group χ² = 36.600, P < 0.001,deltoid muscle group χ² = 29.947, P < 0.001), day 1 were 20.4% (115/564) and 17.6% (100/568), day 2 were 16.0% (90/564) and 13.4% (76/568), day 3 were 10.3% (58/564) and 10.6% (60/568), day 4-7 were 11.2% (63/564) and 11.3% (64/568). No serious adverse events (SAE) were reported during the study. The local reactions incidence of two groups were 7.1% (40/564) and 7.7% (44/568)with no statistical differences (χ² = 0.176, P = 0.675). The systemic reactions incidence of two groups were 25.9% (146/564) and 20.6% (117/568) with obvious statistical differences (χ² = 4.437, P = 0.035). The fever incidence of vastus lateralis muscle group (11.5% (65/564)) was higher than Deltoid muscle group (4.4% (25/568)) with obvious statistical differences (χ² = 4.868, P = 0.027). The 1st dose incidence of fever and abnormal crying of vastus lateralis muscle group (fever 11.3% (23/204), abnormal crying 19.1% (39/204)) was higher than deltoid muscle group (fever 4.4% (9/204), abnormal crying 11.8% (24/204)) and the 2nd dose of diarrhea of deltoid muscle group (11.6% (22/190)) was higher than vastus lateralis muscle group (5.9% (11/187)) with obvious statistical differences (fever χ² = 15.288, P < 0.001, abnormal crying χ² = 4.224, P = 0.040, diarrhea χ² = 3.829, P = 0.046)., Conclusion: Both vastus lateralis muscle group and deltoid muscle group had lower incidence of adverse reactions after vaccination. No serious adverse events were associated with vaccination. Vastus lateralis muscle vaccination as well as deltoid muscle vaccination demonstrated safe.

Objective: To analyze the capsule related surface properties of Porphyromonas gingivalis (Pg) isolates., Methods: The transmission electron microscopy (TEM) was used to observe the capsule structure and the capsule thickness of 2 type of strains and 5 clinical isolates. Microbial adhesion to hydrocarbons (MATH) assay was used to qualitatively assess the hydrophobicity of each strain, and the capacities of these strains were investigated by autoaggregation assay.Ninety-six well biofilm assay and confocal laser scanning microscopy (CLSM) were applied to quantify and observe the biofilm produced by each strain., Results: TEM showed the variety of capsule thickness of these strains.Virulent type strain W83 possessed thicker capsular structure than less-virulent type strain ATCC33277. The SJD4 possessed thicker capsule than other clinical isolates, followed by SJD11, SJD5, SJD2, and SJD12.Strains W83, SJD4, SJD11, with thicker capsule, were much more hydrophilic with lower MATH percentage, in accordance with a slow autoaggregation in incubation during a period of 240 min. Compared with W83, the hydrophobicity of strains ATCC33277, SJD5, SJD2, and SJD12, with thinner capsule, showed increased MATH percentage and autoaggregations. All clinical strains developed biofilm with different absorbance compared with type strains. The CLSM observation showed biofilm thickness of each strain, ranged from (14.74 ± 4.99) to (24.13 ± 5.45) µm. Strain W83 and SJD11 showed notable poor biofilm formation, while others developed dense and mature biofilm., Conclusions: There was a certain degree of linkage between the Pg capsule thickness and surface properties diversity.

Objective: To express human-mouse chimeric antibody against Yersinia pestis F1 capsular antigen (F1 antigen) and analyze its biological activities., Methods: The heavy chain gene of the chimeric antibody was obtained by fusing the variable region gene of the mouse mAb heavy chain with human IgG1 constant region gene. The light chain gene of the chimeric antibody was obtained by fusing the variable region gene of the mouse mAb light chain with the human kappa constant region gene. Both the heavy and light chain genes of the chimeric antibody were further verified by sequencing. The chimeric antibody heavy and light chain genes were inserted into EcoR I/Not I of pcDNA3.1 (+) to construct expression plasmids termed pcDNA3.1-L and pcDNA3.1-H, respectively. Then, two plasmids were mixed and transfected into CHO-S cells. Finally, the stable cell clone secreting chimeric antibody was obtained by G418 selection. The culture supernatants of serum-free medium were collected and the chimeric antibody was purified by MabSelect SuRe affinity chromatography. The purified chimeric antibody was analyzed by SDS-PAGE, Western blotting, ELISA and evaluated in the protective effect in vivo., Results: PCR and sequencing analysis proved that plasmids pcDNA3.1-H and pcDNA3.1-L were correctly constructed. Dot blot showed that a cell line with high-level expression of chimeric antibody was obtained. SDS-PAGE and western blot showed that the chimeric antibody was successfully purified. ELISA showed that the chimeric antibody could specifically bind to F1 antigen. In vivo activity assay showed that 80% BALB/c mice treated with the chimeric antibody survived from 36 MLD virulent Yersinia pestis., Conclusion: The chimeric antibody against F1 antigen with neutralizing activity was successfully expressed in CHO-S cells, which laid a foundation for the preparation of anti-plague passive immunity agents.

Objective: To determine whether Acanthamoeba polyphaga could affect the survival and growth of Vibrio cholerae O139 in low temperature., Methods: V. cholerae O139 was co-cultured with the Acanthamoeba polyphaga to be examined on its intracellular growth and survival rate within cysts at low temperature, using methods as Gram-staining, electron microscope and passage culture., Results: V. cholerae O139 were observed to enter into the trophozoites and grow the within the vacuoles after 8 hour incubation with Acanthamoeba polyphaga. The germs survived in the vacuole and/or endo-layer of wall and could be re-isolated from the excystment of Acanthamoeba polyphaga. At 30 degrees C, V. cholerae O139 could survive for 120 days with the amoeba while less than 45 days in PAS. At 4 degrees C, the number of viable bacteria decreased and reached undetectable levels for both study and control groups after a 30-day incubation. V. cholerae O139 could be re-isolated from the 30-, 45-, 60- and 75-day's infected cysts after excystment. However the ability of excystment for 90-day's infected cysts decreased and V. cholerae O139 within the cyst could not be isolated again because the amoebae had lysed., Conclusion: These findings indicated that V. cholerae O139 could grow within Acanthamoeba polyphaga and the survival time could be increased in the cysts at low temperature. It seemed that Acanthamoeba can provide an environmental reservoir for V. cholerae O139.