ABSTRACT
Objective To investigate positive picobirnaviruses(PVBs)infection and its association with unex-plained diarrhea in children. Methods From January to December 2015,the Clinical Microbiology Testing Center of Xuzhou Central Hospital as the sampling location,7 PVB reverse transcription - polymerase chain reaction(RT - PCR)- positive fecal samples with diarrhea were collected from children under 6 years old and 4 samples from healthy chil-dren were obtained and all the samples were analyzed by viral metagenomics to investigate the relationship between PVBs and diarrhea in children. Phylogenetic analysis of RdRp in the isolated PVB sequences was carried out to clarify the relationship between PVB classification and diarrhea. Results All the 7 diarrhea feces contained high titers of PVB sequences,while 3 of the controls were negative,and 1 with low titers of PVB. RdRp analysis was carried out on the iso-lated PVB sequences,which displayed that 7 RdRp sequences caming from 7 fecal samples separately,so named ChXz- 1 to ChXz - 7 respectively. Phylogenetic analysis based on the predicted amino acid sequences of RdRp from this study and whole RdRp sequences available in the GenBank database indicated that the 7 RdRp sequences belonged to 3 genogroups,in which ChXz - 1,ChXz - 2,ChXz - 3 belonging to genogroup Ⅰ,ChXz - 4,ChXz - 5,ChXz - 7 belong-ing to genogroup Ⅱ,and ChXz - 6 belonging to genogroup Ⅲ. Conclusions PVBs might be the cause of diarrhea in children in this study,and all the 3 different PVBs may lead to diarrhea.
ABSTRACT
Objective To analyze the resistance of Stenotrophomonas maltophilia to commonly used antibacterial drugs,and to investigate the existence status of 3 kinds of integron(Ⅰ,Ⅱand Ⅲ)and the carrying drug resistance gene cassettes so as to offer help for better preventing and controlling the infectious diseases caused by stenotrophomonas maltophilia in local place.Methods 51 strains of Stenotrophomonas maltophilia from clinical samples were collected and the minimum inhibitory concentration(MIC)of 17 kinds of antibacterial drugs to stenotrophomonas maltophilia was measured by the broth microdilution antifungal susceptibility test(Mi-AFST).3 kinds of integron(Ⅰ,Ⅱand Ⅲ)were amplified by PCR with primers designed according to registrated DNA se-quence in GenBank.The variable region products in the positive integron strains were amplified and performed the sequencing analy-sis.The homological comparison in the Genebank database was performed on the sequencing results for finding out what gene was included in variable domain of those integrons.Results (1)Among 51 strains of stenotrophomonas maltophilia,41 srains (80.39%) were collected from sputum samples,and the infected crowd was dominated by individuals aged over 60 years,38 strains accounted for 74.5%.In the department distribution,20 strains(39.22%)were collected from ICU,13 strains (25.49%)from the respiratory department and 6 strains(11 .76%)from the veteran cardres wards,which accounted for the larger proportion.(2)The drug suscep-tibility test demonstrated that stenotrophomonas maltophilia strains had the higher resistance to most of commonly used antibacteri-al drugs,some strains even showed the multi-drug resistance to over 9 kinds of antibacterial drugs.(3)The PCR gene amplification results showed that 7 strains (13.7%)were positive integronⅠ,while no strains containing integron Ⅱ or ⅢI were detected;the resistance genes carried in the variable region of integron I included the 5 kinds of aacA4,aadA1,catB8,dfrA17 and aphA15.Conclu-sion Stenotrophomonas maltophilias has relatively high resistance to majority of commonly used antibacterial drugs in clinic,and some strains show the muti-drug resitance.IntegronⅠis one of important factors for the multi-drug resistance of Stenotrophomonas maltophilias.