Clinical characteristics,molecular epidemiology and antimicrobial susceptibility of pertussis among children in southern China

Background Increasing numbers of pertussis cases have been reported in recent years.The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China.The epidemiology of antigenic genotype and antibiotic resistance of circulating strains in children have been unknown in Shenzhen,southern China.The aim of this study was to describe the clinical features and explore the genotypes and antimicrobial susceptibility of circulating Bordetella pertussis among children in Shenzhen.Methods Data of hospitalized children with pertussis in Shenzhen Children's Hospital from August 2015 to April 2017 were collected.The genetic variability of isolates was investigated and Etest was performed for phenotypic susceptibility to erythromycin,azithromycin,clarithromycin,clindamycin,and trimethoprim/sulfamethoxazole.Results 469 children with pertussis confirmed by real-time quantitative polymerase chain reaction were hospitalized and strains were isolated from 105 patients.White blood cell count≥20×10^9/L and lymphocyte proportion≥60%were observed in 39.29%of infants younger than 3 months.The two predominant profiles of virulence-associated allelic genes were ptxA1/ptxC1/ptxPl/prnl(48.6%)and ptxA1/ptxC2/ptxP3/prn2(44.8%).Among the isolates,48.6%(51/105)were found resistant to macrolides.Conclusions These findings indicate that leukocytosis is not a sensitive indicator of pertussis.Isolates with the gene profile ptxP3/prn2 were highly circulating in Shenzhen and less resistant to macrolides,different from patterns observed in other parts of China.

Antimicrobial effect of sodium houttuyfonate on Staphylococcus epidermidis and Candida albicans biofilms

OBJECTIVE: To study antimicrobial effect of Sodium houttuyfonate(SH) on Staphylococcus epidermidis(SE) and Candida albicans(CA). METHODS: The prepared strain broths(OD600 =0.05) containing SE and CA were firstly used to test the minimal inhibitory concentrations(MICs) of SH, azithromycin(AZM) and fluconazole(FLU) by micro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with different concentrations by crystal violet staining method. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS: The MICs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and 3rd day of medications, the suppressions of biofilm were about 60%(P<0.01), 76%(P=0.000) and 75%(P=0.000) by 2×MIC SH, the suppressions of biofilm were about 90%(P=0.000), 88%(P=0.000) and 90%(P=0.000) by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION: SH had widely anti-pathogenic effect on pathogenic biofilm formation of either bacteria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular polymeric substances, and was more active to inhibit the growth of CA than SE.

Vitisin B inhibits influenza A virus replication by multi-targeting neuraminidase and virusinduced oxidative stress

The development of drug-resistant influenza and new pathogenic virus strains underscores the need for antiviral therapeutics.Currently,neuraminidase(NA)inhibitors are commonly used antiviral drugs approved by the US Food and Drug Administration(FDA)for the prevention and treatment of influenza.Here,we show that vitisin B(VB)inhibits NA activity and suppresses H1N1 viral replication in MDCK and A549 cells.Reactive oxygen species(ROS),which frequently occur during viral infection,increase virus replication by activating the NF-κB signaling pathway,downmodulating glucose-6-phosphate dehydrogenase(G6PD)expression,and decreasing the expression of nuclear factor erythroid2-related factor 2(Nrf2)antioxidant response activity.VB decreased virus-induced ROS generation by increasing G6PD expression and Nrf2 activity,and inhibiting NF-κB translocation to the nucleus through IKK dephosphorylation.In addition,VB reduced body weight loss,increased survival,decreased viral replication and the inflammatory response in the lungs of influenza A virus(IAV)-infected mice.Taken together,our results indicate that VB is a promising therapeutic candidate against IAV infection,complements existing drug limitations targeting viral NA.It modulated the intracellular ROS by G6PD,Nrf2 antioxidant response pathway,and NF-κB signaling pathway.These results demonstrate the feasibility of a multi-targeting drug strategy,providing new approaches for drug discovery against IAV infection.

Effect of sodium houttuyfonate on symptom pattern of lung-Qi deficiency in rats induced by bacterialbiofilm infection

OBJECTIVE: To investigate the in vivo inhibitory effects of sodium houttuyfonate(SH) on symptom pattern of Qi-deficiency in rats induced by infection of bacterial biofilm on rat respiratory tract.METHODS: Symptom pattern is a term used in Traditional Chinese Medicine(TCM) to define a cluster of symptoms in a medical condition. Based on the pattern, TCM therapies are administered. The symptom pattern used in this study was lung-Qi deficiency pattern identified in rats, which was induced by nasal intubation drip of Pseudomonas aeruginosa(P. aeruginosa)(two strains) to form bacterial biofilm on airway combined with stimulation of cold and fatigue. We measured the variations of the symptoms of the pattern, weight, spleen and thymus index, blood gas, lung bronchial tissue pathology and cytokine of rat in different treatments and control groups.RESULTS: The rats of SH-treatment groups had not showed typical symptoms comparing with model group in the early stage of infection. The weight,spleen and thymus index of the SH-treatment groups were significantly higher comparing with untreated model group. The SH-treatment groups also showed higher O2 partial pressure and lower CO2 partial pressure than model group. Furthermore, we found that the bronchopulmonary section of SH-treatment groups not showed typical pathogenic variation in model group. The comparison of cytokine concentration in different groups indicated that SH could prevent the over-production of cytokine to reduce the inflammation occurrence.CONCLUSION: In the early stage of airway infection by biofilm of P. aeruginosa, application of SH can prevent the occurrence of lung-Qi deficiency pattern.

Retinoic acid enhances lactoferrin-induced IgA responses by increasing betaglycan expression

Lactoferrin （LF） and retinoic acid （RA） are enriched in colostrum, milk, and mucosal tissues. We recently showed that LF-induced IgA class switching through binding to betaglycan （transforming growth factor-beta receptor III, TpRIII） and activation of canonical TGF-p signaling. We investigated the combined effect of LF and RA on the overall IgA response. An increase in IgA production by LF was further augmented by RA. This combination effect was also evident in Ig germ-line α （GLa） transcription and GLa promoter activity, indicating that LF in cooperation with RA increased IgA isotype switching. We subsequently found that RA enhanced TβRIII expression and that this increase contributed to LF-stimulated IgA production. In addition to the IgA response, LF and RA in combination also enhanced the expression of the gut-homing molecules C-C chemokine receptor 9 （CCR9） and a4β7 on B cells. Finally, peroral administration of LF and RA enhanced the frequency of CCR9＋ IgA＋ plasma cells in the lamina propria. Taken together, these results suggest that LF in cooperation with RA can contribute to the establishment of gut IgA responses.

Implication of Corynebacterium species in food’s contamination

Corynebacterium spp.are part of the human microbiota.Recently,species of this genus are increasingly implicated in different types of infections especially in immunocompromized and hospitalized patients.The significance of the presence of the genus Corynebacterium in foods is not clearly established.These bacteria may be involved in spoilage or ripening of cheese and meats.This review focused on different researches concerning the implication of Corynebacterium species in food’s contamination.

The role of anti-glutamic acid decarboxylase autoantibodies in mood disorders

Gamma-aminobutyric acid(GABA)possibly plays a causative role in mood disorders.This hypothesis originated with studies on the beneficial effect of valproate in mania and as a mood stabilizer.Since valproate is known for its action in increasing the level of GABA,it was indirectly suggested that decreasing levels of GABA were responsible for mood alterations.To identify factors causing the decreased levels of GABA,studies have concentrated on the activity of the enzyme L-glutamic acid decarboxylase(GAD),which catalyzes the transformation of glutamate to GABA,as a decreasing function of this enzyme induces lower levels of the neurotransmitter.Moreover,a very limited amount of research investigated the possible role of glutamic acid decarboxylase antibodies(GADA)in determining a decreased enzymatic function of GAD.If these findings are confirmed,it will be possible to improve diagnosis and treatment of mood disorders.In addition,if the presence of GADA is associated with a genetic trait,this would allow and facilitate early diagnoses.