Objective:To analyze the features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) co-infected with other common respiratory pathogens among coronavirus disease 2019 (COVID-19) patients in Shanghai City, and to provide a reference for scientific prevention and control of COVID-19 and other respiratory infectious diseases.Methods:Descriptive epidemiological approaches were used to analyze the data of COVID-19 reported cases in Shanghai City from January 2020 to February 2021 in the information system of Chinese Disease Prevention and Control. Clinical data of the participants were collected, and their SARS-CoV-2 nucleic acid-positive respiratory specimens were collected at the time of illness onset or admission. Multiplex reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the 22 respiratory pathogens. Independent-samples t test was used for statistical analysis. Results:Of the 272 patients with COVID-19, 15(5.5%) had co-infection of SARS-CoV-2 with other respiratory pathogens, all of which were double infection. There were three cases infected with enterovirus/rhinovirus, two of each with adenovirus, human metapneumovirus and coronavirus NL63/HKU1, and one of each with coronavirus 229E, influenza A virus H1N1, parainfluenza virus 1 and respiratory syncytial virus B. Two cases infected with Mycoplasma pneumoniae. Among the 272 COVID-19 patients, 212(77.9%) had fever, 117(43.0%) had cough, 46(16.9%) had fatigue, and 35(12.9%) had sore throat. The white blood cell count of co-infection cases was higher than that of non-co-infection cases ((6.8±1.7)×10 9/L vs (5.3±1.6)×10 9/L), and the difference was statistically significant ( t=3.09, P=0.008). Conclusions:There is a certain proportion of co-infection of SARS-CoV-2 with other respiratory pathogens among the COVID-19 cases in Shanghai City, mainly viral pathogens, especially enterovirus/rhinovirus. A rational combination of drugs was recommended to improve the cure rate. Surveillance of acute respiratory infection should be further strengthened as well.

ObjectiveTo determine the distribution of various antibiotic resistance genes （ARGs） in raw water from drinking water source， and to explore the correlation between the ARGs and common carbapenem-resistant and multidrug-resistant bacteria isolated from drinking water source， so as to provide scientific evidence for improving the safety of urban drinking water. MethodsA total of 30 raw water samples were collected from a major drinking water source in Shanghai in 2020. Bacterial strains were selectively cultured on Columbia blood agar medium containing 1 μg·μL^-1 meropenem， and then identified by MALDI-TOF-MS mass spectrometry system. Minimum inhibitory concentration （MIC） of the strains was detected by broth microdilution method. The water samples were filtered through a 0.45 μm filter membrane and diversity of ARGs was determined by using high-throughput metagenomic sequencing. ResultsA total of 64 strains of carbapenem-resistant bacteria were isolated from the water samples， including Stenotrophomonas maltophilia， Enterococcus faecium， Pseudomonas aeruginosa， Acinetobacter baumannii and Klebsiella pneumoniae， which were resistant to a variety of common antibiotics. Using metagenomic sequencing，1 244 ARGs were identified. The relative average abundance of the top 100 ARGs accounted for 96.1%， and that of the multidrug-resistant ARGs accounted for 63.41%. Furthermore， the multidrug-resistant ARGs were mainly adeJ， mexT， adeC， oprM， mexF， mdfA， mexB， mdtK， adeK， etc. Using Spearman's correlation， five multidrug-resistant bacteria isolated from the drinking water source were significantly associated with the ARGs. ConclusionRelative abundance of multidrug-resistant ARGs is high in raw water from main drinking water source. The five isolated carbapenem-resistant and multidrug-resistant bacteria are significantly correlated with the ARGs. It warrants strengthening the rational and standardized application of antibiotics to protect water resources and ensure the safety of drinking water.

Objective:To discuss the challenges and problems of the prevention and control of emerging infectious diseases in Shanghai as a megacities.Methods:An imported case of cutaneous anthrax occurred in Shanghai on May 30, 2019. Shanghai Municipal Center for Disease Control & Prevention conducted an epidemiological investigation and treatment of the cases; after this case, the data of patients with cutaneous anthrax were collected, and an epidemiological study was conducted. Meanwhile, the wound and blood samples of the patient were collected for laboratory testing.Results:Of the seven wound samples of the patient, 6 were positive for the Bacillus anthracis nucleic acid test, and the double serological test results showed a 4-fold increase in the titer of anthrax antibodies. Shanghai CDC conducted an epidemiological investigation of the confirmed cases and observed its contacts. After treatment, the patients recovered, and no other issues appeared among the 19 contacts. Conclusions:Shanghai must strengthen the training of clinicians on emerging infectious diseases to achieve early detection, diagnosis, and treatment of imported infectious diseases and reduce the incidence, spread, and death of the diseases. At the same time, multi-department joint prevention and control are needed to prevent and control secondary cases.

Objective: To investigate the molecular characterization of adult diarrhea cases caused by enterotoxic Escherichia coli (ETEC) and explore the practical model of epidemiology for laboratory technique and data needs based on the surveillance network. Methods: Epidemiological design and sampling targeted adult cases ETEC caused diarrhea in epidemic season. The enterotoxin type, serogroup, resistance, colonization factor and molecular type of ETEC were identified. Multiple dynamic phenotypic characteristics of ETEC were indicated by multidimensional and multivariable data. Results: From 2016 to 2018, 84 eligible ETEC strains were detected. The dominant serums/toxins were O∶6 (STh), O∶25 (LT), O∶159 (STh), O∶153 (STh). O∶6 (STh+CS21), which replaced O∶25 and O∶159 as the popular clones in 2018. Six cases of O∶153 (STh+CFA/I+CS8+PT34) in outbreak in 2017 were imported ones. The resistance rates of ETEC strains detected in adults to sulfasoxazole, naproxinic acid, ampicillin and azithromycin were more than 30%, multidrug resistance (MDR) reached 58.3%. Serum/toxin types suggested that attenuated strains were more likely to become MDR. Molecular typing confirmed that the genetic similarity of the dominant clone of O∶6 serogroup (PT20-24) was higher than O∶25 and O∶159. There was a high correlation between the minimal inhibitory concentration (MIC) of azithromycin and the resistant gene mphA (87.5%, 28/32). O∶6 (STh+CS21+mphA) resistant clone was first detected in 2016. Conclusion A new epidemic clone in adult ETEC diarrhea cases in Shanghai was O∶6 (STh+CS21+mphA). For the first time the association between azithromycin resistance gene mphA and a serum group of ETEC was observed. Multidimensional and multivariate analysis techniques based on epidemiology can help reveal the potential transmission pattern of ETEC for the accurate surveillance and early warning of outbreaks.

Objective: To understand the seasonality and etiological characteristics of infectious diarrhea in adults from Shanghai. Methods: Adult patients with diarrhea who had visited the enteric disease clinics in 22 hospitals that carrying on the Diarrhea Comprehensive Surveillance sentinel programs in Shanghai during 2014-2017, were surveyed. Stool specimens were collected according to the different intervals of sampling and detected for 12 bacteria and 5 viruses. Concentration ratio and circular distribution method were used for data analysis. Results: From 2014 to 2017, a total of 9 573 stool specimens were collected from the targeted diarrhea patients ≥18 years old (n=96 067), through the Shanghai Diarrhea Comprehensive Surveillance program. The positive rate of detection was 46.44%. Seasonal peaks of infectious diarrhea were both seen in summer (bacteria peak, diarrheagenic Escherichia coli and Vibrio parahaemolyticus, etc.) and in winter (virus peak, Norovirus, etc.). Both bacterial and viral infections presented seasonal concentration (Raleigh’s test P<0.001) but more obvious with bacterial infection. Viral infection accounted for 60.19% of the cause of infectious diarrhea. The top five predominant pathogens appeared as Norovirus, Rotavirus, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, and Salmonella spp.. Conclusions Among the adult outpatients with infectious diarrhea in Shanghai, obvious seasonality was seen, with peaks in both summer and winter. Viral infection with Norovirus in particular, appeared as the predominant source of infection. Active, continuous and comprehensive diarrhea-related surveillance programs would be able to monitor the changing dynamic of pathogen spectrum, and lead to the adoption of targeted preventive measures.

Objective: To understand the epidemiological characteristics and antibiotic resistance profiles of Campylobacter spp. in Shanghai from 2013 to 2016. Methods: Stool samples collected from diarrhea outpatients were cultured for Campylobacter spp., using the membrane filter method in 23 hospitals under the sentinel programs, from 2013 to 2016. All the strains were identified by biochemical tests and PCR. Broth microdilution method was used to investigate the antibiotic resistance of 179 Campylobacter spp. strains that including azithromycin, ciprofloxacin, erythromycin, gentamicin, tetracycline, nalidixic acid, telycin, klinthromycin and flurbenicol. Results: A total of 179 Campylobacter spp. strains were isolated from 10 444 stool samples (1.7%). Campylobacter jejuni and Campylobacter coli appeared as the predominant ones (94.4% and 5.6%). The incidence rate was higher in children than that in adults, with peaks of infections mainly from April to June and October to December. Campylobacter jejuni strains seemed highly resistant to ciprofloxacin (96.4%), tetracycline (83.4%) and nalidixic acid (81.7%). The resistant rates appeared higher on Campylobacter coli strains that isolated from patients. Some strains were resistant to multi-drugs. Conclusions Campylobacter spp. seemed one of the important pathogens that isolated from outpatients with diarrhea, in Shanghai. Both age and season related characteristics of Campylobacter spp. were seen. Campylobacter spp. isolated from patients was highly resistant to ciprofloxacin, tetracycline and nalidixic acid.

Objective To investigate the antimicrobial resistance proifle of Shigella flexneri in Shanghai from 2010 to 2014 and examine the mechanism of fluoroquinolone resistance.Methods Kirby-Bauer method was used to determine the susceptibility of the S. flexneri strains to 14 antibiotics. The minimum inhibitory concentration (MIC) of ciprofloxacin was tested by E-test. Mutations within quinolone resistance determining regions (QRDR) of gyrA and parC and plasmid-mediated quinolone resistance (PMQR) genes,qnrA,qnrB,qnrS andaac(6')-Ib-crwere identified by polymerase chain reaction (PCR). All the products were subjected to sequencing analysis.Results More than 90 % of the 139S. flexneri isolates were resistant to ampicillin, streptomycin, tetracycline, and nalidixic acid, 40.3 % to ciprofloxacin and 30.2 % to cefepime, respectively. Genetic mutation of gyrA and parC was found in 98.6 % and 97.8 % of the strains, respectively. Three point mutations (Ser83, Asp87 and His211) were detected in gene gyrA and one point mutation (Ser80) was found in in gene parC. Plasmid-mediated resistant gene qnrS was found in 9 strains and aac(6')-Ib-cr in 6 strains.Conclusions The antibiotic resistance of S. flexneri is serious in Shanghai. The mutation rate within QRDR is high. Point mutation in Asp87 of gyrA is the main mechanism of quinolone resistance. The plasmid-mediated quinolone-resistant genes also play an important supplementary role.

AIM: To investigate the effects of propofol on the expression of tissue-type plasminogen activator (tPA) and matrix metalloproteinase 9 (MMP9) in the hippocampus and the cognitive function in neonatal rats.METHODS: The 7-day-old rats were randomly divided into 3 groups: the rats in control (CON) group were intraperitoneally injected with normal saline for 7 d;the rats in single dose of propofol anesthesia (SP) group were intraperitoneally injected with normal saline for 6 d and with propofol on the 7th day;the rats in repeated dose of propofol anesthesia (RP) group were intraperitoneally injected with propofol for 7 d.Blood glucose and blood gas analysis were tested in 6 rats of each group.The rats were randomly selected from each group to isolate the hippocampal tissues at 2 h, 24 h, 48 h, 72 h and 30 d after the last injection.The spatial learning and memory functions of the other rats aged 25 d were determined by Morris water maze.The morphological changes of the hippocampus were observed by HE staining and Nissl's staining.The expression of tPA and MMP9 at mRNA and protein levels was determined by RT-PCR and Western blot.RESULTS: Compared with group CON, the protein expression of tPA and MMP9 in RP group was significantly decreased at each time point, while no significant decrease was observed in SP group except at the time point of 24 h.Compared with CON group, the mRNA expression of tPA and MMP9 was down-regulated obviously in RP group, which was not significantly down-regulated in SP group.From the 3rd training day of Morris water maze beginning, the escape latency was prolonged, and the space exploration time and the number of crossing the original platform location were reduced in RP group compared with CON group and SP group, while no significant difference was observed between CON group and SP group.Compared with CON group, the number of nerve cells reduced and nerve cells arranged in disorder in the hippocampus in RP group.Moreover, the number of Nissl body decreased significantly and finally developed into neuronal degeneration and necrosis in RP group, and no significant difference between SP group and CON group was observed.CONCLUSION: Repeated dose of propofol anesthesia leads to long-term cognitive dysfunction in neonatal rats, which may be related to the down-regulation of tPA and MMP9 expression and destruction of normal morphology and function of neurons in hippocampus, whereas single dose of propofol anesthesia has no such effects.

Aim To observe the improvement effects of parecoxib on ventricular remodeling after acute myocardial infarction in rats and its influence on PI3K/Akt signaling pathway.Methods Forty male Sprague-Dawley rats were randomly divided into five groups(n=8):sham operation group (group S), ventricular remodeling model group(group R), low dose of parecoxib group(group P1), middle dose of parecoxib group(group P2), and high dose of parecoxib group(group P3).A myocardial infarction model was established by ligating the left anterior descending branch(LAD) of coronary artery in group R, group P1, group P2 and group P3.One day after the operation,the rats were given intraperitoneal injection of 4,8,12 mg·kg-1 parecoxibin Group P1, group P2 and group P3,respectively, for two weeks.The same volume saline was given in group S and group R.Four weeks later, LVSP, LVEDP,+dp/dtmax,-dp/dtmax were monitored.The hearts were harvested to calculate left ventricular hypertrophy index.The pathological change of heart was examined with an optical microscope.The expressions of atrial natriuretic peptide(ANP) mRNA and brain natriuretic peptide(BNP) mRNA were detected by RT-PCR.The expression of PI3K,Akt,P-Akt and caspase-3 was detected by Western blot.Results Compared with group S, the cardiac function was decreased, the left ventricular hypertrophy index, the expression levels of ANP,BNP mRNA, caspase-3 were increased, and the expression levels of PI3K, P-Akt were reduced in group R(all P<0.05).Compared with group R, the cardiac function was ameliorated, the left ventricular hypertrophy index were reduced in group P2 and group P3(all P<0.05).The expression levels of ANP,BNP mRNA, Caspase-3 were decreased, and the expression levels of PI3K and P-Akt were increased in group P1,group P2 and group P3(all P<0.05).Conclusions Middle and high doses of parecoxib can mitigate the process of ventricular remodeling after myocardial infarctionand improve the myocardial function, and its underlying mechanism may be related to activating PI3K/Akt signaling pathway.

Aim To investigate the role of matrix metalloproteinase-9 down-regulation in the learning and memory dysfunction induced by propofol treatment in rats.Methods 7-day-old SD rats were randomly divided into three groups(n=18):control group(NS group) and repeated doses of propofol group(RP group) was intraperitoneally injected with normal saline and propofol respectively for consecutive seven days, single dose of propofol group(SP group) were intraperitoneally injected with normal saline first for consecutive six days, and then injected with propofol on 7th day.The blood gas and glucose levels were monitored of six rats randomly selected from each group.Morris water maze was conducted to test the learning and memory functions of the remaining rats.The expression of MMP-9, BDNF and caspase-3 was detected by Western blot, and the hippocampal neuron apoptosis was determinated by TUNEL staining.Results Compared with NS group and SP group, the escape latency in RP group was prolonged significantly, exploration time and the number of crossing the platform in RP group were markedly decreased(P<0.05).The expressions of MMP-9 and mBDNF in RP group declined, but the expression of proBDNF and the ratio of proBDNF/mBDNF in RP group were higher than those in NS group and SP group(P<0.05).Compared with NS group and SP group, the number of apoptotic neurons and the expression of cleaved-caspase-3 in RP group were increased significantly, but the expression of pro-Caspase3 in RP group was reduced(P<0.05).There was no difference between SP group and NS group regarding all the results(P>0.05).Conclusions Repeated exposure to propofol can lead to a decline in long-term learning and memory functions in neonatal rats, which may be related to the down-regulation of MMP-9 expression, proBDNF and mBDNF conversion disorder in hippocampus and the apoptosis of hippocampal neurons.However, single exposure to propofol has no significant effect.