Objective To obtain information on the distribution of serotypes and antimicrobial agents susceptibilities to group B streptococcus(GBS) strains. Methods Bacterial isolates of GBS were obtained from vaginal and cervical tract of pregnant and nonpregnant women in Beijing Tian Tan Hospital. A total of 76 GBS strains were identified finally by Coagglutination. Serotyping was determinted by Standard Lancefield method. Susceptibility to test agents was assessed by determining the mininum inhibitory concentrations (MICs) with agar dilution method that was established by the National Committee for Clinical Laboratory Standards (NCCLS). Results Seven serotypes were identified among 76 GBS strains isolates. Type II(33%), III(23%) and Ia(16%) were the predominantly serotypes in pregnant and nonpregnant women. MICs of penicillin G and anpicillin were≤0.06 ?g/ml; MICs of cephazolin,cefuroxime, cefoperozone were 0.006～0.03 ?g/ml; MICs of erythromycin was 0.003～0.03 ?g/ml;MICs of gentamycin was 1～32 ?g/ml,MICs of amikacin was 4～≥64 ?g/ml,nearly 12.8% and 40.4% the strains were resistant to gentamycin and amikacin,respectively. Conclusion Our study provide useful epidemiologic data for preparation of GBS type specific vaccines which can prevent GBS infections and antimicrobial agents susceptibility patterns in China. Routine reports on GBS susceptibolities by clinical laboratories and continuous surveillance for changes in the susceptibility is of considerable clinical importance.

Objective To learn the influence on the outcome of the pregnant by measuring the type Ⅲ antibody of Group B Streptococcus(GBS). Methods During December 31, 1997 to December 31, 2000, 28 pregnant women whose GBS screening were positive were selected as study group while 46 negative as control group. Vaginal swab cultures were conducted in 74 pregnant women at different gestational periods(before 20 gestational weeks, 20~28 weeks and after 34 weeks). After birth maternal and cord blood samples were collected immediately for the test of GBS IgG antibody with ELISA method. Results 28 of 74 women(37.8%)were GBS culture positive in the antenatal screening. The obstetrical complications such as gestational diabetes millitus, impaired glucose tolerance test, fetal growth retardation, premature rupture of membrane, threatened premature labor and asphyxia of newborn have no significant difference between the GBS carrier group and non-carrier group. The result was same for the newborns. The antibody(IgG)of GBS value of the 74 pairs of maternal and cord blood samples showed that the values of IgG in maternal blood samples and cord blood samples were (3.1?2.2) mg/L and (2.3?1.8) mg/L, respectively,r=0.86,P

Objective To evaluate the value of polymerase chain reaction (PCR) combined with probe detection method in diagnosis of Mycoplasma pneumonia (MP) pneumonia (MPP) in children and to analyze the factors influencing the diagnostic accuracy,and to identify the rate of MP mutation for drug resistance and the involving factors.Methods Two hundred and twenty-five children with MPP hospitalized in the Department of Respiratory Medicine,Beijing Children's Hospital,Capital Medical University between June 2015 and March 2016 were enrolled in this study.Nasopharyngeal swab samples from the participants within 24 hours of admission were detected by using PCR combined with fluorescence probes for MP-DNA and macrolide-resistant mutations.The information of age,sex,clinical symptoms,course of disease,duration by admission,the history of macrolide treatment and the increase or decrease of quadruple or more serum MP antibody titer were extracted from medical records within 4 weeks of treatment,which received further correlation analysis with the detection rate of MP-DNA and the drug resistance mutation.Results The sensitivity of the MPP by using the method of PCR combined with fluorescence probes was 80.4％ (181/225 cases),while the specificity was 98.0％ (99/101 cases).The MP-DNA positive rate for patients with double MP antibody 4 times increased during treatment was 88.8％ (71/80 cases),which was significantly higher than that of patients with antibody titer ≥1 ∶ 160 [75.9％ (110/145 cases)],and the difference was sigmficant(x =5.443,P =0.020).The positive rate of MP-DNA of patients had no obvious association with gender,age,and disease duration and macrolide treatment history before admission.Macrolide-resistant mutation rate of MP-DNA was 85.1％ (154/181 cases),macrolide-resistant mutation rate of MP for patients finishing one course of macrolide treatment when admission(89.6％)was higher than that of the patients without using macrolide and the patients treated with macrolide but not finishing one course of treatment (71.9％ and 86.6％),and the significant difference among the three groups was observed(x2 =4.454,P =0.035).Conclusions PCR combined with fluorescence probe for MP-DNA detection has a high accuracy for the diagnosis of MPP,and the overall mutation rate is high,suggesting that the clinical treatment of MPP needs to be adjusted according to drug resistance in children.

Objective To evaluate the application of multiple locus variable number tandem repeat analysis (MLVA, 15-locus set)for genotyping of Mycobacterium tuberculosis (MTB) strains of Beijing genotype. Methods Total 72 Beijing genotype MTB strains obtained from Beijing Thoracic Hospital were genotyped by MLVA (15-locus set). The results were compared with that generated from "gold standard"IS6110-RFLP. Results After genotyped by MLVA ( 15-locus set), 72 strains were grouped into 59 types,of which 53 were unique types. The Hunter-Gaston index (HGI) of MLVA ( 15-locus set) was 0.990. The loci QUB-11b, Mtub 21 and QUB-26 were polymorphic in selected Beijing genotype strains. Genotyping by IS6110-RFLP generated 69 types, of which 66 were unique types. The HGI of IS6110-RFLP was up to 0.999, and the MLVA (15-locus set) clustered strains could be further subdivided. Conclusion MLVA(15-locus set) showed better discriminatory ability in Beijing genotype MTB strains, though secondary typing of clustered strains by IS6110-RFLP is needed.

Objective To obtain information on the distribution of serotypes and antimicrobial agent susceptibilities to group B streptococcus (GBS) strains isolated in Beijing area from 1991 to 1996. Methods Bacterial isolates of GBS were obtained from vaginal and cervical tract of pregnant and nonpregnant women in Beijing Tian Tan Hospital by culture. A total of 76 GBS strains were identified finally by coagglutination. Serotyping was determined by Standard Lancefield method. Susceptibility to test agents was assessed by determining the minimal inhibitory concentrations (MICs) with agar dilution method that was established by the National Committee for Clinical Laboratory Standards (NCCLS).Results Seven serotypes were identified among 76 GBS strains isolates. Types Ⅱ (33%), Ⅲ (23%) and Ⅰa (16%) were the predominant serotypes in pregnant and nonpregnant women. MICs of penicillin G and ampicillin were ≤0.06 μg/ml. MICs of cephazolin, cefuroxime and cefoperozone were 0.003 μg/ml - 0.06 μg/ml. MICs of erythromycin were 0.003 μg/ml - 0.03 μg/ml. MICs of gentamycin were 1 μg/ml - 32 μg/ml. MICs of amikacin were 4 μg/ml - ≥64 μg/ml, nearly 12.8% and 40.4% of the strains were resistant to gentamycin and amikacin, respectively.Conclusions Our study provides useful epidemiologic data for preparation of GBS type-specific vaccines which can prevent GBS infections and antimicrobial agents susceptibility patterns in China. Routine reports on GBS susceptibilities by clinical laboratories and continuous surveillance for changes in the susceptibility are of considerable clinical importance.

Tuberculosis (TB) is a serious threat to children′s health.The world health organization (WHO) reported that there were almost 1 million TB patients and 230 000 deaths among children globally in 2017.In order to control the prevalence of childhood TB, WHO put forward a blueprint of " towards zero death for childhood TB" . However, due to the difficulty in obtaining specimens, the lack of typical symptoms and the insufficient of existing diagnostic methods for children, it is hard to achieve the goal of zero death.The summary of the TB diagnosis status will promote to solve the current problems in children.

Hypoxemia is a common complication of pneumonia, asthma, and bronchopulmonary dysplasia in children.Rapid identification of hypoxemia is of great significance for the disposal and management of critical children.Pulse oximetry is recognized by the World Health Organization as the best way to monitor hypoxemia in children, and it can monitor pulse oxygen saturation noninvasively and continuously.Based on the related literature at home and abroad, combined with the clinical needs of pediatrics, the " Expert consensus on clinical application of pulse oximetry in children" is formulated to improve the understanding of pediatricians and nurses on the application in pediatric clinical practice, principle, operation techniques, and limitations of pulse oximetry.

At present, severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)infection is still rampant worldwide.As of September 10, 2021, there were about 222 million confirmed cases of corona virus disease 2019(COVID-19)and more than 4.6 million deaths worldwide.With the development of COVID-19 vaccines and the gradual vaccination worldwide, the increasing number of cases in children and unvaccinated young people has drawn attention.According to World Health Organization surveillance data, the proportion of COVID-19 infection cases in children gradually increased, and the proportion of cases in the age groups of under 5 years and 5-14 years increased from 1.0% and 2.5% in January 2020 to 2.0% and 8.7% in July 2021, respectively.At present, billions of adults have been vaccinated with various COVID-19 vaccines worldwide, and their protective effects including reducing infection and transmission, reducing severe disease and hospitalization, and reducing death, as well as high safety have been confirmed.Canada, the United States, Europe and other countries have approved the emergency COVID-19 vaccination in children and adolescents aged 12 to 17 years, and China has also approved the phased vaccination of COVID-19 vaccination in children and adolescents aged 3 to 17 years. For smooth advancement and implementation of COVID-19 vaccination in children, academic institutions, including National Clinical Research Center for Respiratory Diseases, National Center for Children′s Health, and The Society of Pediatrics, Chinese Medical Association organized relevant experts to reach this consensus on COVID-19 vaccination in children.

Tuberculosis is still a big threat to children.However, due to the particularity of tuberculosis in children, there are many problems in diagnosis and treatment, such as the clinical manifestations and symptoms of children are not specific, clinicians do not pay enough attention to the disease, the specimen for pathogen detection is difficult to obtain, the sensitivity of existing diagnostic methods is not enough, lack of child-friendly anti-tuberculosis drugs, pharmacokinetic/pharmacodynamics researches of anti-tuberculosis drugs in children and anti-tuberculosis treatment regimens based on children studies.This paper summarizes the above-mentioned problems and their countermeasures and prospects.

For safety reasons, Fluoroquinolones should be used with caution in children.The current consensus is that quinolones should not be banned in children.In clinical practice, under the condition of fully evaluating the risk and benefit, it can be used as appropriate for severe infection and multi-drug resistant pathogen infection.Therefore, this paper summarizes the application of Fluoroquinolones in the treatment of severe and drug-resistant respiratory infectious diseases, safety analysis and damages of joints and cartilages, pharmacokinetic studies and drug resistance in children.The paper aims to provide a reference for the treatment of severe and drug-resistant infectious diseases in children.