[Respiratory Tract Infection Pathogen Spectrum Study of 376 Pneumoconiosis Inpatients in Chengdu].

OBJECTIVE: To investigate the status of infections caused by respiratory pathogens and the patterns of infections caused by pathogens in different seasons, age groups and stages of pneumoconiosis so as to explore the pathogen spectrum of respiratory tract infections in pneumoconiosis patients. METHODS: The sputum samples of 376 pneumoconiosis patients admitted to an occupational disease hospital in Chengdu between January, 2017 and October, 2019 were collected. Clinical information of the patients was collected and lab tests were conducted to check for 23 kinds of common respiratory viruses, bacteria and fungi in the sputum. The relationship between seasons, ages, and different stages of pneumoconiosis and the pathogen detection rate was analyzed. RESULTS: In the 376 sputum samples, the detection rates of pathogens, viruses, bacteria and fungi were 42.29% (159/376), 32.98% (124/376), 9.57% (36/376) and 6.12% (23/376), respectively. The six pathogens with the highest detection rates were parainfluenza virus, rhinovirus, influenza virus, Candida albicans, Klebsiella pneumoniae and Candida krousei. The severity of respiratory tract infection did not show significant difference in different seasons, age groups, and pneumoconiosis stages. CONCLUSION: The pathogen spectrum of respiratory tract infections in patients with pneumoconiosis is complicated and the proportion of viral infection is high. However, the severity of the infection is not associated with age, seasonal, or pneumoconiosis staging differences.

Prevalence and clinical profile of rotavirus A infection among diarrhoeal children and phylogenetic analysis with vaccine strains in Chengdu, West China, 2009-2014.

OBJECTIVES: Rotaviruses are the most common cause of severe diarrhoeal disease in young children. However, little is known about the epidemiological and clinical profile of rotavirus A (RVA) in diarrhoeal children or the efficacy of Lanzhou lamb rotavirus vaccine (LLR) in Chengdu, China. This study aimed to determine the prevalence and clinical profile of RVA in diarrhoeal children and provide gene analysis information for RVA vaccination programmes. METHODS: A total of 1121 faecal samples were collected from outpatient children with diarrhoea between 2009 and 2014. RT-PCR was performed to detect RVA infection and other gastroenteritis viruses. VP4 and VP7 genes of 13 RVA strains were sequenced to compare their similarity with vaccine strains. RESULTS: The overall RVA infection rate was 17.48%. G1 (54.72%) and G3 (18.87%) were the predominant G genotypes; P[8] (72.36%) and P[4] (11.38%) were the main P genotypes. Sixteen genotypes were identified; G1P[8] (57.33%) and G9P[8] (12.00%) were the most prevalent. The proportion of coinfection with RVA and other gastroenteritis viruses was 18.88%. RVA was mostly detected in winter and in diarrhoeal children 1-2 years of age. The genotypes of Rotarix and RotaTeq vaccines were consistent with RVA strains prevalent in Sichuan and shared high identity. CONCLUSIONS: RVA was one of the major aetiological agents of diarrhoeal children in Chengdu. Genotype distribution differed within each year and the gene analysis implied low efficacy of LLR. Continuous epidemiological monitoring of RVA is essential for the national vaccination programme.

Human cytomegalovirus prevalence and distribution of glycoprotein B, O genotypes among hospitalized children with respiratory infections in West China, 2009-2014.

OBJECTIVES: Human cytomegalovirus (HCMV) is an important pathogen causing morbidity and mortality in children. HCMV prevalence in children with respiratory infections has not been investigated in West China. Previous studies have suggested that glycoproteins genotypes may be associated with different clinical presentations, but the associations were controversial. The aim of this study was to determine the prevalence of HCMV infection in children with respiratory infections, the distributions of gB, gO genotypes among these isolates and their potential predictive roles for the development of symptoms in children. METHODS: A total of 1709 respiratory specimens were obtained from hospitalised children with respiratory symptoms from 2009 to 2014 for the confirmation of HCMV infection. Glycoprotein B,O genotyping was carried out by multiplex nested PCR and sequencing. RESULTS: The overall infection rate was 10.8%, and dominant genotypes were gB1 (74.2%) and gO1 (37.1%). Clinical characteristics differed between infants and children >1 year of age. Infants infected with HCMV had a higher frequency of fever (P < 0.001), cough (P < 0.001), rhinorrhea (P < 0.001), expectoration (P = 0.001) and diarrhoea (P = 0.005). Children <1 year age infected with gB1 had a higher rate of cough (P = 0.0192). CONCLUSIONS: Infants infected with HCMV had a severe clinical outcome. gB1 may negatively associate with clinical presentations and quality of life in these children. The prevalence of HCMV infection and genotype distribution emphasises the importance of HCMV screening, vaccination and control for transmission.

[Isolation and Study on the Aflatoxin Genes of Aflatoxin-producing Fungi in Paprika Samples in Chengdu].

OBJECTIVE: To isolate aflatoxin-producing strains from paprika samples and to do a preliminarily study on the relationship between aflatoxin-producing ability and the genes aflR, omt-1 and ver-1. METHODS: Fungi were isolated by traditional culture method. Potential aflatoxin-producing strains were screened by phenotypic traits and multiplex PCR. After these potential aflatoxin-producing strains cultured in the toxigenic culture medium, the levels of aflatoxin B, (AFB1) of the cultures were tested with ELISA method. The phylogenetic tree of aflR, omt-1 and ver-1 was constructed to explore the relationship between these genes and the AFB1-producing capacity. RESULTS: 17 potential aflatoxin-producing fungi were isolated. The ratio of positive toxigenic strains is 64. 71%. 11 isolates were positive in AFB1 detection while existing high sequence homology with AS 3. 4408, 6 isolates were negative in AFB1 detection while existing high sequence homology with Aspergillus oryzae. CONCLUSION: Aspergillus flavus are potential candidates for aflatoxin control. Not all Aspergillus flavus have AFB1-producing capacity, aflR gene had a direct relation to AFB1-producing capacity, while ver-1 and omt-1 were related to the level of AFB1 producing.

[Application of PulseNet China Database in tracking and warning 4 cholerae outbreaks in Anhui province, in 2012].

OBJECTIVE: To track the source of infection regarding 4 Cholerae outbreaks in Anhui province in 2012 through the application of PulseNet China Database (PNCD). METHODS: Cholerae virulence genes were amplified by PCR and typed by pulse field gel electrophoresis(PFGE). Results from electrophoresis were cluster-analyzed by BioNumericsV4.0 software and compared with PNCD. RESULTS: Virulence gene CT and TCP of the tested vibrio cholera showed both positive. Homology of the strains from four cholera outbreaks was more than 98%, based on the homologous and cluster analysis through enzyme digested PFGE electrophoresis. Those strains were highly homologous with the cholera epidemic strains identified in Hunan, Sichuan,Zhejiang, Shanghai and Hubei by PNCD, with the homology as 100% . CONCLUSION: Four cholera outbreaks in Anhui province, 2012 were highly correlated with the outbreaks occurring in Hunan and Sichuan during the same time period, indicating that PNCD could effectively and quickly tracking down the source of infection on the cholera outbreaks and providing early warning of the situation.