ABSTRACT
A large number of viral and bacterial organisms are responsible for community-acquired pneumonia (CAP) which contributes to substantial burden on health management. A new resequencing microarray (RPM-IVDC1) associated with targeted multiplex PCR was recently developed and validated for multiple respiratory viruses detection and discrimination. In this study, we evaluated the capability of RPM-IVDC1 for simultaneous identification of multiple viral and bacterial organisms. The nasopharyngeal aspirates (NPAs) of 110 consecutive CAP patients, aged from 1 month to 96 years old, were collected from five distinct general hospitals in Beijing during 1-year period. The samples were subjected to the RPM-IVDC1 established protocol as compared to a real-time PCR (qRT-PCR), which was used as standard. The results of virus detection were consistent with those previously described. A total of 37 of Streptococcus pneumoniae, 14 of Haemophilus influenzae, 10 of Mycoplasma pneumoniae, two of Klebsiella pneumoniae and one of Moraxella catarrhalis were detected by RPM-IVDC1. The sensitivities and specificities were compared with those of qRT-PCR for S. pneumoniae (100, 100%, respectively), H. influenzae (92.3, 97.9%, respectively), M. pneumoniae (69.2, 99.0%, respectively), K. pneumoniae (100, 100%, respectively), and M. catarrhalis (100, 100%, respectively). Additional 22 of Streptococcus spp., 24 of Haemophilus spp. and 16 of Neisseria spp. were identified. In addition, methicillin-resistant and carbapenemases allele were also found in nine of Staphylococcus spp. and one of K. pneumoniae, respectively. These results demonstrated the capability of RPM-IVDC1 for simultaneous detection of broad-spectrum respiratory pathogens in complex backgrounds and the advantage of accessing to the actual sequences, showing great potential use of epidemic outbreak investigation. The detection results should be carefully interpreted when introducing this technique in the clinical diagnostics.
ABSTRACT
OBJECTIVE: To investigate the serotype virulence genes and molecular typing characteristics of Vibrio Parahaemolyticus isolated from diarrhea samples among 2007 -2012. METHODS: The serotype was detected by using serological agglutination test. Thermo-stable direct hemolysin (tdh) and tdh-related hemolysin (trh) were detected by using real time PCR methods. 56 strains 03:K6 were analyzed for molecular typing by pulsed field gel electrophoresis(PFGE). RESULTS: (1) There are 14 serotypes, including 03: K6 (114,67.9%),04: K8 (25,14.9%), 03: K29 (6,3.6%) and et al. Compared with the serotypes of strains from food poison, these from sporadic cases with diarrhea were different, but the main serotype was also 03:K6. (2) There are 4 types of virulence genes, including tdh+ trh- (161, 95.8%), tdh+ trh+ (3,1.8%), tdh- trh+ (1, 0.6%) tdh- trh- (3, 1.8%). Compared with the virulence genes of strains from food poison, these from sporadic cases with diarrhea were different, but the main virulence gene was also tdh+ trh-. 3,56 strains belonged to 15 PFGE strips and the similar degree is higher than 86%. 10 patterns (P1-P4, P6, P7, P9, P10, P12, P15) had at lest two strains. CONCLUSION: The most V. Parahaemolyticus isolated from clinical patients was 03: K6 and tdh+ trh-. PFGE strips of V. Parahaemolyticus of 03: K6 from clinical patients exhibited a high degree of similarity, and correlation was found among strains.
