Objective To evaluate serum level of pepsinogenⅠ( PGⅠ) ,PGⅡ, and PGⅠ/PGⅡ-ratio ( PGR ) using latex enhanced turbidimetric immunoassay in patients with different gastric mucosal lesions, and to investigate their changes and clinical significance.Methods Case-control study.Two hundred and seventy-five patients who had enteroscopy and pathological examination from the department of gastroenterology and surgery from Beijing Tongren Hospital between January 2015 and January 2016 were enrolled.Endoscopic and histopathological examination confirmed the normal control group (n=20), chronic non-atrophic gastritis group ( n=68 ) , chronic atrophic gastritis group ( n=76 ) , including antral atrophic gastritis ( n=30 ) , gastric body atrophic gastritis ( n=26 ) , and multifocal atrophic gastritis ( n=20 );intestinal metaplasia group ( n=28 ) , intraepithelial neoplasia group ( n=9 ) , benign gastric ulcer group ( n=46) and intestinal gastric cancer group ( n=28).Latex-enhanced immune turbidity method were used to detect the patients fasting serum PGⅠand PGⅡ.Then the PGR was calculated.The normally distributed data of each group were statistically analyzed by ANOVA, the data between groups were nalyzed using the Mann-Whitney U test and Kruskal-Wallis test.Results Serum PGⅠ[ ( 74.23 ±22.36 ) ] ng/ml and PGR (6.92 ±2.16) in chronic atrophic gastritis group were lower than those in normal controls[PGⅠ(98.94 ± 21.00) ng/ml, PGR 8.13 ±2.47],(FPGⅠ =18.297,PPGⅠ <0.01,FPGR =4.713,PPGR <0.01).The serum PGⅠ[(44.46 ±26.72) ng/ml] and PGR (3.09 ±0.83) in the intestinal type of gastric cancer group were lower than those in the chronic atrophic gastritis group[PGⅠ(74.23 ±22.36)ng/ml, PGR 6.92 ±2.16], (ZPGⅠ =-3.921,PPGⅠ <0.01,ZPGR =-6.662,PPGR <0.01).PGⅠ[(129.95 ±43.39) ng/ml].PGⅡ[(21.09 ±6.78) ng/ml]in the gastric benign ulcer group were higher than those in the normal controls[PGⅠ (98.94 ±21.00) ng/ml, PGⅡ(12.64 ±1.84) ng/ml], FPGⅠ =10.803,PPGⅠ <0.01;FPGⅡ =39.130,PPGⅡ <0.01. PGⅠ[(52.44 ±10.37) ng/ml and PGR (5.47 ±1.59) in the multifocal atrophic gastritis group were lower than those in the antral atrophic gastritis[PGⅠ(94.95 ±14.45)ng/ml, PGR 8.39 ±1.48],ZPGⅠ =-5.941,PPGⅠ <0.01,ZPGR =-4.911,PPGR <0.01.The AUC of PGⅠand PGR for diagnosis of chronic atrophic gastritis were 0.752 and 0.683 respectively.The sequence combined detection sensitivity was 72.37%(55/76), and the specificity was 70.85%(141/199).The AUC of PG I and PGR for diagnosis of intestinal type of gastric cancer were 0.852 and 0.895 respectively.The sequence combined detection sensitivity was 71.42% ( 20/28 ) and the specificity was 81.78% ( 202/247 ) . Conclusion The Latex-enhanced immune turbidity method of combined detection of serum PGⅠ, PGⅡlevels and PGR can be used in the clinic to monitor the status and function of gastric mucosa and are informative for gastric cancer and precancerous lesions of gastric mucosa.

Objective To study the genotypic and biological characteristics of catheter-related MRSE isolates and to further provide information for the diagnosis and prevention of catheter-related bloodstream infection. Methods Thirty strains of catheter-related MRSE isolates were collected from venosus blood and whole blood of 30 inpatients including 20 males and 10 females from Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2009. The genetic features of these strains were determined by MLST. PCR was used to detect the icoA gene (encoding the polysaccharide intercellular adhesion associated with pathogenicity), and the antimicrobial susceptibility test was detected by disc diffusion test. Results A total of 15 STs were obtained from 30 strains ST259, ST20, ST2 and ST235 were common clones obtained from 17 strains. Four novel STs were found and uploaded to the MLST database (http://www. mlst. net), including ST259 (6 strains), ST260 (1 strain), ST261 (1 strain) and ST262 (1 strain). The ST259 was the dominant clone of catheter-related MRSE isolates in this hospital, and 3 strains carrying icaA gene were detected in this study. Conclusion Some ST259 isolates express high pathogenesis among the four novel STs, which may make them as the pandemic strains in nosocomial infection, and this would increase the difficulty of the prevention and control of nosocomial infection.

Objective To study on virulence characteristics and multilocus sequence type of Vibrio parahaemolyticus isolated from clinic in Beijing Tongren hospital.Methods Total 152 strains of Vibrio parahaemolyticus isolates were collected from diarrheal patients of outpatients in Beijing Tongren Hospital,Capital Medical University from 2009 to 2011.PCR was used to detect hemolysin gene thermo stable direct themolysin gene (tdh),TDH-related hemolysin gene (trh),type Ⅲ secretion system 2 (T3SS2α,T3SS2β)and systematic functional gene (toxRS/new,orf8) for pandemic 03∶ K6 clone and its derivatives.The genetic features of these strains were determined by multilocus sequence typing (MLST).Results 96％ (146/152) VP harbored tdh gene,2％ (3/152) VP harbored trh gene and 100％ (152/152) VP harbored T3SS2 gene.In this study there were 107 pandemic strains (both tdh and toxRS/new positive and trh negative),38 pathogenic strains (tdh positive and/or trh positive) and 6 nonpathogenic strains (both tdh and trh negative).All nonpathogenic strains harbored systematic functional gene (toxRS/new,orf8).Only one pathogenic strains harbored orf8 gene.One clone harbored all virulence gene.In this study there were 16 sequence types,and ST3 is the pandemic sequence type,including 113 strains,and four new sequence types were found.Conclusions In this study more than 90％ Vibrio haemolyticus harbored tdh gene and ST3 was the pandemic sequence type in Beijing.One can get bacterial pathogenic charateristic and population genetics information by virulence gene testing and MLST.

Objective To investigate the epidemic tendency and drug resistance of common pathogenic bacteria in the patients with infectious diarrhea,and then provide scientific evidence for the treatment of bacterial diarrhea.Methods The feces specimens were collected from 12 156 patients with infectious diarrhea in our hospital during April 1,2012 and October 31,2017.Then,they were cultured,and the obtained bacteria were isolated and identified by the Vitek 2 Compact system and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS).The serotype and drug resistance of the obtained bacteria were analyzed by the agglutination test and K-B disk diffnsion method,respectively.Results A total of 1 218 strains (10.02％,1 218/12 156) of pathogenic bacteria were isolated from 12 156 feces specimens,including 926 (7.62％,926/12 156) strains of Vibrio,96 (0.79％,96/12 156) strains of Aeromonas,178 (1.46％,178/12 156) strains of Salmonella and 18 (0.15％,18/12 156) strains of Shigella.The detection rates of pathogenic bacteria per year were 9.2％,11.9％,13.4％,7.0％,11.3％ and 7.2％,respectively,from 2012 to 2017.The detection rate of Shigella was low,but it had a high resistance to ampicillin and compound sulfamethoxazole (SMZ-TMP).Other pathogenic bacteria were more sensitive to SMZ-TMP,ceftriaxone,aztreonam,gentamycin and quinolones except ampicillin.Conclusion The main pathogenic bacterium in the patients with infectious diarrhea is Vibrio,and Shigella has the highest resistance to most drugs.The overall infection tendency is sporadic.It is necessary to strengthen the monitoring of pathogenic bacteria and their drug resistance in the patients with infectious diarrhea.

Objective:To explore the distribution characteristics of pathogens in adult patients with community-acquired pneumonia (CAP) and to provide basis for the diagnosis, treatment, prevention of CAP.Methods:1 446 inpatients with CAP were prospectively enrolled in a third-class hospital in Beijing in recent 5 years (from January 2015 to December 2019). Respiratory tract samples were collected for smear, culture, nucleic acid, antigen and antibody detection to identify the pathogen of CAP. Mann-Whitney U test was used for continuous variables and χ 2 test or Fisher′s exact test was used for categorical data for statistical analysis. Results:Among the 1 446 patients, 822 (56.85%) patients were infected with a single pathogen, 231 (15.98%) patients were infected with multiple pathogens, and 393 (27.18%) patients were not clear about the pathogen. Influenza virus is the first pathogen of CAP (20.95%, 303/1 446), mainly H1N1 (8.51%, 123/1 446), followed by mycoplasma pneumoniae (7.19%, 104/1 446), Mycobacterium tuberculosis (5.33%, 77/1 446) and Streptococcus pneumoniae (5.05%, 73/1 446). The outbreak of H1N1 occurred from December 2018 to February 2019, and the epidemic of mycoplasma pneumoniae pneumonia was monitored from August to November 2019. Patients under 65 years old had high detection rates of Mycoplasma pneumoniae (14.41% vs. 2.41%, χ2=74.712, P<0.001), Streptococcus pneumoniae (8.16% vs. 2.99%, χ2=18.156, P<0.001), rhinovirus (6.08% vs. 3.56%, χ2=5.025, P<0.025), Chlamydia pneumoniae (5.90% vs. 1.15%, χ2=26.542, P<0.001) and adenovirus (3.13% vs. 0.92%, χ2=9.547, P=0.002). The severe disease rate of CAP was 14.66% (212/1 446), and the average mortality rate was 3.66% (53/1 446). The severe illness rate and mortality rate of bacterial-viral co-infection were 28.97% (31/107) and 19.63% (21/107), respectively. Conclusions:Influenza virus is the primary pathogen of adult CAP. Outbreaks of Mycoplasma pneumoniae and H1N1 were detected in 2018 and 2019, respectively. The remission rate and mortality rate of virus-bacteria co-infection were significantly higher than those of single pathogen infection. Accurate etiological basis not only plays a role in clinical diagnosis and treatment, but also provides important data support for prevention and early warning.

Objective:To explore the distribution characteristics of pathogens in adult patients with community-acquired pneumonia (CAP) and to provide basis for the diagnosis, treatment, prevention of CAP.Methods:1 446 inpatients with CAP were prospectively enrolled in a third-class hospital in Beijing in recent 5 years (from January 2015 to December 2019). Respiratory tract samples were collected for smear, culture, nucleic acid, antigen and antibody detection to identify the pathogen of CAP. Mann-Whitney U test was used for continuous variables and χ 2 test or Fisher′s exact test was used for categorical data for statistical analysis. Results:Among the 1 446 patients, 822 (56.85%) patients were infected with a single pathogen, 231 (15.98%) patients were infected with multiple pathogens, and 393 (27.18%) patients were not clear about the pathogen. Influenza virus is the first pathogen of CAP (20.95%, 303/1 446), mainly H1N1 (8.51%, 123/1 446), followed by mycoplasma pneumoniae (7.19%, 104/1 446), Mycobacterium tuberculosis (5.33%, 77/1 446) and Streptococcus pneumoniae (5.05%, 73/1 446). The outbreak of H1N1 occurred from December 2018 to February 2019, and the epidemic of mycoplasma pneumoniae pneumonia was monitored from August to November 2019. Patients under 65 years old had high detection rates of Mycoplasma pneumoniae (14.41% vs. 2.41%, χ2=74.712, P<0.001), Streptococcus pneumoniae (8.16% vs. 2.99%, χ2=18.156, P<0.001), rhinovirus (6.08% vs. 3.56%, χ2=5.025, P<0.025), Chlamydia pneumoniae (5.90% vs. 1.15%, χ2=26.542, P<0.001) and adenovirus (3.13% vs. 0.92%, χ2=9.547, P=0.002). The severe disease rate of CAP was 14.66% (212/1 446), and the average mortality rate was 3.66% (53/1 446). The severe illness rate and mortality rate of bacterial-viral co-infection were 28.97% (31/107) and 19.63% (21/107), respectively. Conclusions:Influenza virus is the primary pathogen of adult CAP. Outbreaks of Mycoplasma pneumoniae and H1N1 were detected in 2018 and 2019, respectively. The remission rate and mortality rate of virus-bacteria co-infection were significantly higher than those of single pathogen infection. Accurate etiological basis not only plays a role in clinical diagnosis and treatment, but also provides important data support for prevention and early warning.