To explore the antiviral effect and mechanism of polysaccharide from Spirulina platensis (PSP) on herpes simplex vims type 2 (HSV-2), a standard strain of HSV-2 (333 strain) was used to investigate the antiviral effec...To explore the antiviral effect and mechanism of polysaccharide from Spirulina platensis (PSP) on herpes simplex vims type 2 (HSV-2), a standard strain of HSV-2 (333 strain) was used to investigate the antiviral effect of PSP in vitro . PSP in various concentrations was applied to different stages of HSV-2 replication cycle. Finally, the virus infectivity (TCID50),cytopathic effect (CPE), and MTT staining method for viable cells (MTT assay) were used as markers to evaluate the effect of PSP on HSV-2. The quantity of HSV-DNA was detected by real-time fluorescence quantitative PCR (FQ-PCR). The HSV-2 infected Vero cell ultrastructures were observed by transmission electron microscopy (TEM). The results showed that PSP had little cytotoxic effect on Vero cells, it could not directly inactivate HSV-2 infectivity. PSP not only interfered in adsorption of HSV-2 to Vero cells but also inllibited HSV-2 biosynthesis in the cells. FQ-PCR results showed that the inhibitory rate on HSV-DNA also increased in a dose-dependent and time-dependent manner. TEM also confirmed that PSP exhibited pronounced inhibitory effect on HSV-2. In conclusion, the antiviral effect of PSP on HSV-2 may be attributed to the inhibition of vims adsorption, vims replication and synthesis in cells.展开更多
This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from pati...This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from patients who presented with urinary tract infection at Federal Teaching Hospital Gombe. Isolates collected were recovered on MacConkey agar at 35<span style="white-space:nowrap;">°</span>C and were identified as members of Enterobacteriaceae, and further screened for antimicrobial susceptibility and resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were confirmed as ESBL producers using Double Disks Synergy Test (DDST). The study shows 66% resistance to ceftriaxone (30 μg) in <em>K. pneumoniae</em>, which was the highest value recorded and a 51% resistance to cefpodoxime (10 <em>μ</em>g) in <em>E. coli</em>. The sensitivity of <em>E. coli </em>and <em>K. pneumoniae</em> isolates to cefpodoxime (10 <em>μ</em>g) were 49% and 33.9% respectively. ESBLs were detected among 40% (40/100) of <em>E. coli</em> and 54.13% (59/109) of <em>K. pneumoniae</em> isolates. Molecular characterization of ESBL encoding genes among <em>E. coli</em> isolates using multiplex-PCR showed 10% prevalence of SHV gene and 5% prevalence for CTX-M gene while TEM gene was not detected. In <em>K. pneumoniae</em> isolates, 5% prevalence was recorded for each of the three genes screened. The study revealed a co-occurrence of SHV and CTX-M in 75% of the <em>E. coli</em> and 70% of the <em>K. pneumoniae</em> isolates;the occurrence of all the three genes was seen in 10% and 5% of <em>K. pneumoniae</em> and <em>E. coli</em> respectively. Multiplex-PCR method provided an efficient and rapid detection of ESBL related genes, hence could be used in epidemiological studies among ESBL isolates. Monitoring dissemination and transmissions of ESBL producers are highly recommended for optimum patient care and preventing the spread of multidrug resistant (MDR) pathogens.展开更多
文摘To explore the antiviral effect and mechanism of polysaccharide from Spirulina platensis (PSP) on herpes simplex vims type 2 (HSV-2), a standard strain of HSV-2 (333 strain) was used to investigate the antiviral effect of PSP in vitro . PSP in various concentrations was applied to different stages of HSV-2 replication cycle. Finally, the virus infectivity (TCID50),cytopathic effect (CPE), and MTT staining method for viable cells (MTT assay) were used as markers to evaluate the effect of PSP on HSV-2. The quantity of HSV-DNA was detected by real-time fluorescence quantitative PCR (FQ-PCR). The HSV-2 infected Vero cell ultrastructures were observed by transmission electron microscopy (TEM). The results showed that PSP had little cytotoxic effect on Vero cells, it could not directly inactivate HSV-2 infectivity. PSP not only interfered in adsorption of HSV-2 to Vero cells but also inllibited HSV-2 biosynthesis in the cells. FQ-PCR results showed that the inhibitory rate on HSV-DNA also increased in a dose-dependent and time-dependent manner. TEM also confirmed that PSP exhibited pronounced inhibitory effect on HSV-2. In conclusion, the antiviral effect of PSP on HSV-2 may be attributed to the inhibition of vims adsorption, vims replication and synthesis in cells.
文摘This study was conducted to assess the occurrence and nature of extended-spectrum beta lactamase (ESBL) producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> isolates from patients who presented with urinary tract infection at Federal Teaching Hospital Gombe. Isolates collected were recovered on MacConkey agar at 35<span style="white-space:nowrap;">°</span>C and were identified as members of Enterobacteriaceae, and further screened for antimicrobial susceptibility and resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were confirmed as ESBL producers using Double Disks Synergy Test (DDST). The study shows 66% resistance to ceftriaxone (30 μg) in <em>K. pneumoniae</em>, which was the highest value recorded and a 51% resistance to cefpodoxime (10 <em>μ</em>g) in <em>E. coli</em>. The sensitivity of <em>E. coli </em>and <em>K. pneumoniae</em> isolates to cefpodoxime (10 <em>μ</em>g) were 49% and 33.9% respectively. ESBLs were detected among 40% (40/100) of <em>E. coli</em> and 54.13% (59/109) of <em>K. pneumoniae</em> isolates. Molecular characterization of ESBL encoding genes among <em>E. coli</em> isolates using multiplex-PCR showed 10% prevalence of SHV gene and 5% prevalence for CTX-M gene while TEM gene was not detected. In <em>K. pneumoniae</em> isolates, 5% prevalence was recorded for each of the three genes screened. The study revealed a co-occurrence of SHV and CTX-M in 75% of the <em>E. coli</em> and 70% of the <em>K. pneumoniae</em> isolates;the occurrence of all the three genes was seen in 10% and 5% of <em>K. pneumoniae</em> and <em>E. coli</em> respectively. Multiplex-PCR method provided an efficient and rapid detection of ESBL related genes, hence could be used in epidemiological studies among ESBL isolates. Monitoring dissemination and transmissions of ESBL producers are highly recommended for optimum patient care and preventing the spread of multidrug resistant (MDR) pathogens.
