Objective To investigate the genotype and drug resistance of extended-spectrum beta-lac-tamases(ESBLs) -producing Shigella in pediatric patients.Methods A total of 59 strains of Shigella were isolated from stool specimens of hospitalized children with shigellosis in Beijing Children's Hospital from January 2004 to December 2008.Phenotypic confirmatory test,which is based on Clinical and Laboratory Standards Institute(CLSI),was used to detect the ESBLs-producing strains.Agar dilution method was used to determine the minimal inhibitory concentration (MIC).PCR amplification was performed for ESBLs producers to determine the genotype.PCR product was sequenced and then analyzed to confirm the subtype of ESBLs.Results Of the 59 isolates,21 (35.6%) strains were identified as ESBLs producers.The 21 strains of ESBLs-producing Shigella all carried the genes of CTX-M as shown by PCR,and CTX-M-1,CTX-M-9 accounted for 6,15,respectively.Among the 21 CTX-M producers,there were 4 strains accompanied by TEM-type and 6 strains accompanied by OXA-type.Nucleotide sequence analysis showed that there were CTX-M-3 (n = 1),CTX-M-15 (n = 2),CTX-M-57(n =3) of the 6 CTX-M-1-producing isolates.The subtypes of CTX-M-9,TEM,OXA were all CTX-M-14,TEM-1,OXA-1,respectively.The sensitive drugs to ESBLs producers were imipenem,meropenem,piperacillin/tazobactam,cefoperazone/sulbactam and cefoxitin,with resistance rate all less than 15%.The resistance to ceftazidime was remarkably variable among different CTX-M producers.Conclusion The prevalence of ESBLsproducing Shigella is in a high level in pediatric patients in this area.The genotypes of ESBLs are all CTX-M.Most of them are CTX-M-14,but some are CTX-M-3,CTX-M-15 and CTX-M-57.Most ESBLs-producing strains are multidrug resistant.Carbopenems should be the first choice for ESBLs producers.

Objective To investigate the PCR-based evaluation of prednisolone-induced relapse of asymptomatic Toxoplasma gondii infection and the therapeutic efficacy of azithromycin.Methods A total of 36 of female ICR mice,about 20 g,were randomly divided into 6 groups:contrast group (C),prednisolone group (P),infection group(I),infection plus prednisolone group (IP),infection plus azithromycin group(IA),infection plus prednisolone and azithromycin group (IPA).The infection group (I),infection plus prednisolone group(IP),infection plus azithromycin group(IA),infection plus prednisolone and azithromycin group (IPA)were challenged at week 0 with 10 cysts of Toxoplasma gondii Prugniaud strain per injection intraperitoneally.The prcdnisolone group (P),infection plus prednisolone group (IP) infection plus prednisolone and azithromycin group (IPA)were injectied with prednisolone 1 mg into hind medial subcutaneous every day from the 6th week to 7th week.The infection plus azithromycin group(IA),infection plus prednisolone and azithromycin group (IPA) were injectied with azithromycin 250 mg/kg intraperitoneally every day from the 6th week to 7th week.The serum samples were collected and DNAs extracted at week 0,1,2,3,4,5,6 and 7 for amplification of Toxoplasma gondii of specific B1 gene by PCR.All the mice were sacrificed 7 weeks after the challenge to calculate the number of cysts in brain tissues.Results Compared with the primer of AF146527 gene,the primer of B1 gene was more sensitive and specific.The method of PCR could amplify the productions of specific B1 gene Toxoplasma gondii 5 weeks before the challenge,while it could not amplified 5 weeks after the challenge.All the mice of the IP group were dead 2 weeks after the injection of prednisolone (week 7),and the only two mice of the IPA group were dead at the same time (P <0.05),respectively.Compared with the I group,IA group and IPZ group,the number of cysts in brain tissues of the IP group significantly increased (P <0.01).Conclusions B1 as target gene is more suitable for diagnosis of Toxoplasma gondii infection by PCR.Prednisolone could induce the relapse of asymptomatic Toxoplasma gondii infection of mice and the mice are finally dead.Azithromycin is effective but it can not completely cure the Toxoplasma gondii infection.

The outbreak and spread of coronavirus disease 2019 (COVID-19) highlighted the importance and urgency of the research and development of therapeutic drugs. Very early into the COVID-19 pandemic, China has begun developing drugs, with some notable progress. Herein, we summarizes the anti-COVID-19 drugs and promising drug candidates originally developed and researched in China. Furthermore, we discussed the developmental prospects, mechanisms of action, and advantages and disadvantages of the anti-COVID-19 drugs in development, with the aim to contribute to the rational use of drugs in COVID-19 treatment and more effective development of new drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the variants. Neutralizing antibody is an effective approach to overcome COVID-19. However, drug resistance induced by rapid virus mutation will likely to challenge neutralizing antibodies. Taking into account current epidemic trends, small molecule drugs have a crucial role in fighting COVID-19 due to their significant advantage of convenient administration and affordable and broad-spectrum. Traditional Chinese medicines, including natural products and traditional Chinese medicine prescriptions, contribute to the treatment of COVID-19 due to their unique mechanism of action. Currently, the research and development of Chinese anti-COVID-19 drugs have led to some promising achievements, thus prompting us to expect even more rapidly available solutions.