Search

High PM 2.5 concentration is the main feature of increasing haze in developing states, but information on its microbial composition remains very limited. This study aimed to determine the composition of microbiota in PM 2.5 in Guangzhou, a city located in the tropics in China. In Guangzhou, from March 5th to 10th, 2016, PM 2.5 was collected in middle volume air samplers for 23 h daily. The 16S rDNA V4 region of the PM 2.5 sample extracted DNA was investigated using high-throughput sequence. Among the Guangzhou samples, Proteobacteria, Bacteroidetes, Firmicutes, Cyanobacteria , and Actinobacteria were the dominant microbiota accounting for more than 90% of the total microbiota, and Stenotrophomonas was the dominant gram-negative bacteria, accounting for 21.30%–23.57%. We examined the difference in bacterial distribution of PM 2.5 between Beijing and Guangzhou at the genus level; Stenotrophomonas was found in both studies, but Escherichia was only detected in Guangzhou. In conclusion, the diversity and specificity of microbial components in Guangzhou PM 2.5 were studied, which may provide a basis for future pathogenicity research in the tropics. [ABSTRACT FROM AUTHOR]

Objective: To develop a simple, accurate, rapid, economic, large-scale detection method for the detection of single nucleotide polymorphisms (SNPs) metabolic enzymes, using polymerase chain reaction with confronting two-pair primers (PCR-CTPP)., Methods: The primers of CYP1A1 (A4889G), EPHX1 (A416G) and NQO1 (C609T) were designed for PCR-CTPP, and the PCR conditions were optimized. The results of genotyping were verified by DNA sequencing. The above SNPs were detected by the PCR-CTPP detection method in a randomly selected 183 healthy individuals of Han ethnicity. The genotype frequencies were analyzed and compared with people from other ethnicities., Results: The allele-specific bands of CYP1A1 (A4889G), EPHX1 (A416G) and NQO1 (C609T) were successfully amplified by PCR-CTPP under the optimal conditions and the results of genotyping were consistent with DNA sequencing. Among 183 healthy Han individuals, the genotypic distributions of CYP1A1 (A4889G) , EPHX1 (A416G) and NQO1 (C609T) showed that the wild-type, homozygous variants, and heterozygotes were 103 (56.3%), 8 (4.4%), 72 (39.3%) and 142 (77.6%), 4 (2.2%), 37(20.2%), 60(32.8%), 32 (17.5%), 91 (49.7%) respectively. The distributions of genotypes were all in accordance with the Hardy-Weinberg equilibrium (P > 0.05), with statistical differences and with other ethnic populations (P < 0.05)., Conclusion: The SNPs of metabolic enzymes can be detected by PCR-CTPP method which is simple, accurate, rapid, economic and with large scale. PCR-CTPP can be used for large scale clinical and epidemiological screening.

Objective: To study the alveolar ultrastructural changes and the interaction between Pneumocystis carinii (PC) and alveoli in Pneumocystis carinii pneumonia (PCP) patients after renal transplantation., Methods: Twenty-seven patients with suspected PCP after renal transplantation were examinated by bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB). The BAL fluid was centrifuged and the sediments were stained for PC. Cases for which electron microscope showed alveolar tissue in TBLB specimen were included. Then the clinical features, PC, alveolar epithelial damage, exudate in alveolar space, inflammatory cell infiltration, and fibrous tissue in the interstitial space were analyzed and evaluated., Results: Twenty-three cases were studied. The mean time from renal transplantation to onset of illness was 5.6 months, and that from onset of illness to hospitalization was 5.5 days. Clinical features included fever, dyspnea, unproductive cough, and scanty chest signs, to hypoxemic respiratory failure. Chest CT showed diffuse lung interstitial changes in 22 of the 23 cases, 9 with consolidation. After treatment with SMZco, the fever resolved in 1 - 5 days, and the general state of the patients became better, and 19 patients were dischaged within 1 month. PC in BAL fluid was found by special staining in 18 patients, while PC was found by electron microscope in 14 patients. In most cases PC was few in the lung tissue, but in 3 cases abundant PC filled the alveolar space. PC was seen in two forms, the cyst and the trophozoite. Electron and light microscopes showed alveolar exudate, inflammation in interstitium and alveolar space, interstitial fibrosis, and alveolar epithelial damage in all patients., Conclusion: In PCP patients after renal transplantation there was marked alveolar damage, which was the major pathological change in the lung.