Clinical Distribution,Serotypes and Drug Resistance Analysis of 425 Cases of Invasive Pneumococcal Disease Infectious in Children / 现代检验医学杂志

Objective To analyze the infection distribution,serotypes,and drug resistance of invasive pneumococcal disease(IPD)in children,and provide a reference for the standardized treatment of IPD and the rational use of antibiotics in clinical practice.Methods A total of 425 children with definitive diagnoses of IPD in the Department of Pediatrics,the Affiliated Suzhou Hospital of Nanjing Medical University between March 2019 and November 2022 were selected as the research subjects.Information from the medical records of these children was reviewed,clinical data was collected,serotyping by podoconiosis test on the specimens of Streptococcus pneumoniae strains sent for preservation was determined,and the susceptibility test was performed.Results A sum of 425 children with IPD(with a mean age of 2.16±0.93)were collected in this study.Analysis of clinical infection types showed 189 cases(44.47%)of bacteremia pneumonia,80 cases(18.82%)of simple bloodstream infection,76 cases(17.88%)of septic meningitis,11 cases(2.59%)of infectious pleurisy,9 cases(2.12%)of infective peritonitis,7 cases(1.65%)of bone and joint infection,7 cases(1.65%)of infective endocarditis,and 46 cases(10.82%)of other infections in combination.A total of 14 serotypes were confirmed in this study,with detection rates of 162 cases(38.12%),90 cases(21.18%),42cases(9.88%),38 cases(8.94%),14 cases(3.29%)and 8 cases(1.88%)for serotypes 19F,19A,14,23F,6A,and 6B,respectively.The susceptibility test indicated that the resistance rates of erythromycin and clindamycin were both high,with 95.53%(406/425)and 99.53(423/425),respectively,while the resistance rates of amoxicillin,cefepime,and cefotaxime were all relatively low,with 13.65%(58/425),9.06%(81/425),and 17.18%(73/425),respectively.Comparison between the two groups of cerebrospinal fluid(CSF)isolates and non-CSF isolates showed that the rates of resistance to penicillin were 69.74%and 24.07%(χ2=59.59,P＜0.05),the resistance rates to cefepime were 50.00%and 12.32%(χ2=57.44,P＜0.05),the resistance rates to meropenem were 40.79%and 29.23%(χ2=3.88,P＜0.05),respectively,with statistically significant differences.Conclusion Cultivation identification and drug resistance monitoring of IPD should be strengthened in clinical work.Antibiotics should be effectively used according to the drug susceptibility results to minimize the drug resistance of Streptococcus pneumoniae and improve the efficacy of drug therapy.

Virulence determinants and genetic diversity of foodborne Yersinia enterocolitica isolated from Wenzhou / 中国人兽共患病学报

The aim of this study was to investigate the virulence determinants and genetic diversity of foodborne Yersinia enterocolitica from Wenzhou.A total of 71 strains of Yersinia enterocolitica were isolated from food and foodborne diarrhea ca-ses in Wenzhou,and their biotypes,serotypes,and drug resistance were analyzed.On the basis of whole genome sequencing,we assessed virulence gene profiles,and performed multilocus sequence typing(MLST)and core gene multilocus sequence typ-ing(cgMLST).A total of 94.4％(67/71)of isolates belonged to biotype 1A,and the highest proportion had serotype lA/O∶5(29.6％,21/71).The sensitivity rates of the isolates to 14 antibiotics exceeded 95.8％.A total of 16 categories and 126 viru-lence genes were identified,with two strains carrying the pYV plasmid and chromosome-related virulence genes.ST3(31.6％,12/38)was the most widespread MLST type,and cgMLST analysis revealed no dense clusters of genotypes except for strains sharing the same ST.In conclusion,pathogenic strains were identified from foodborne Yersinia enterocolitica in Wenzhou and were found to exhibit high genetic polymorphism.Enhanced regulatory supervision is essential to prevent the outbreak of food-borne diseases caused by Yersinia enterocolitica.

Investigation,traceability analysis,and discussion of food poisoning caused by Salmonella typhimurium ST19 / 中国人兽共患病学报

To perform a comprehensive analysis of the pathogenic causes of a food poisoning case in a district of Wuhan Cit-y,we investigated the molecular epidemiological relationships among pathogenic bacteria,to aid in traceability analysis of food-borne disease outbreaks,as well as clinical diagnosis and treatment.The pathogenic bacteria in this food poisoning case were i-solated and identified according to GB789.4-2016.The isolated strains were subjected to genotyping with pulsed field gel elec-trophoresis(PFGE).Drug resistance gene analysis,multi-locus sequence typing(MLST),and genome-wide single-nucleotide polymorphism analysis(wgSNP)were conducted via whole genome sequencing(WGS).The evolutionary tree for cluster analy-sis was constructed in fasttree software.Drug susceptibility testing was conducted with the broth microdilution method.A total of 12 strains of Salmonella were detected in seven anal swab samples and two fecal samples from the case,as well as three anal swab samples from unaffected individuals.The serotype of the strains was Salmonella typhimurium.The strain exhibited severe multiple drug resistance,including resistance to amikacin,ampi-cillin,cefazolin,gentamicin,piperacillin,and tetracycline,but susceptibility to other antibiotics.The coincidence rate between drug resistance genes and drug resistance phenotypes was high.PFGE revealed that nine strains from this food poisoning case were highly homologous.WGS revealed that the MLST type was ST19,and varying numbers of SNPs(1-6)were present a-mong strains.The phylogenetic tree revealed nine isolated strains forming a distinct cluster,differing from other Salmonella strains in the database and belonging to a novel clonal branch.The single nucleotide site in the strains was highly homologous to that of GCF in Jiangxi_020221795.1.The food poisoning case was caused by Salmonella typhimurium ST19,and all nine iso-lated strains originated from the same source.The chef is closely connected to this food poisoning case.This strain of Salmo-nella typhimurium belongs to a new clonal branch and exhibits multiple drug resistance.

Serotype distribution and antimicrobial resistance of pediatric Streptococcus pneumoniae isolated from inpatients and outpatients at Beijing Children's Hospital

Abstract Background Understanding the epidemiology of Streptococcus pneumoniae (S. pneumoniae) isolates is important for pneumonia treatment and prevention. This research aimed to explore the epidemiological characteristics of S. pneumoniae isolated from pediatric inpatients and outpatients during the same period. Methods S. pneumoniae were isolated from unsterile samples of inpatients and outpatients younger than five years old between March 2013 and February 2014. The serotypes were determined using diagnostic pneumococcal antisera. The resistance of each strain to 13 antibiotics was tested using either the E-test or the disc diffusion method. The Sequence Types (STs) were analyzed via Multilocus Sequence Typing (MLST). Results The dominant serotypes obtained from inpatients were 19F (32.9 %), 19A (20.7 %), 23F (10.7 %), 6A (10.0 %), and 14 (8.6 %), while those from outpatients were 19F (13.6 %), 23F (12.9 %), 6A (10.0 %), 6B (10.0 %), and 19A (7.9 %). The coverage rates of 13-valent Pneumococcal Conjugate Vaccine (PCV) formulations were high in both groups. The nonsusceptibility to penicillin, cefuroxime, imipenem, erythromycin, and trimethoprim-sulfamethoxazole among the inpatient isolates was 7.1 %, 92.8 %, 65.7 %, 100 %, and 85.0 %, respectively, while that among the outpatient isolates was 0.7 %, 50.0 %, 38.6 %, 96.4 %, and 65.7 %, respectively. There were 45 and 81 STs detected from the pneumococci isolated from inpatients and outpatients, respectively. CC271 was common among both inpatients and outpatients (43.6 % and 14.3 %). Conclusions Pneumococcal vaccine-related serotypes are prevalent among both inpatients and outpatients, especially among inpatients, who exhibit more severe antibiotic resistance. Therefore, universal immunization with PCV13 would decrease the hospitalization rate due to S. pneumoniae and the antibiotic resistance rate of S. pneumoniae.

Primer reporte de un brote de dengue en balsas, Amazonas, Perú, durante 2021 y 2022

Introducción: El aumento de casos de dengue en Amazonas es un riesgo para la salud pública. En el 2021, Balsas reportó por primera vez un brote de dengue. Métodos: La población incluyó a pacientes que cumplían con la definición de caso entre diciembre 2021 y febrero 2022. La identificación de los serotipos se determinó mediante una qRT-PCR múltiplex. Resultados: Se identificaron 72 pacientes de los cuales 53 (74%) se confirmaron por serología (Ag NS1). El serotipo prevalente fue DENV-2 (94%), y el 6% fue DENV-1. Los pacientes de 19 a 45 años presentaron el mayor porcentaje de casos (59%). Los síntomas más frecuentes fueron cefalea, mialgias, fiebre y artralgias; el 23 % presentó dolor abdominal intenso. Conclusión: Este fue el primer brote de dengue confirmado en el distrito de Balsas, siendo DENV-2 el principal causante, destacando la necesidad de mejorar la vigilancia en zonas sin transmisión autóctona de la enfermedad.

Introduction: The increase in dengue cases in Amazonas represents a public health risk. In 2021, Balsas reported a dengue outbreak for the first time. Methods: The population included patients who met the case definition between December 2021 and February 2022. Serotype identification was determined using a multiplex qRT-PCR. Results: A total of 72 patients were identified, of which 53 (74%) were confirmed by serology (NS1 Ag). The prevalent serotype was DENV-2 (94%), and 6% were DENV-1. Patients aged 19 to 45 years had the highest percentage of cases (59%). The most frequent symptoms were headache, myalgia, fever, and arthralgia; 23% had intense abdominal pain. Conclusion: This was the first confirmed dengue outbreak in the Balsas district, with DENV-2 being the main cause of the outbreak, highlighting the need to improve surveillance in areas without autochthonous transmission of the disease.

Vigilancia virológica de casos de Dengue de enero 2020 a febrero 2023, en el Departamento de La Paz-Bolivia / Virological surveillance of Dengue cases since January 2020 to February 2023 La Paz-Bolivia

Introducción: El dengue se ha convertido en un problema serio de salud pública en Bolivia. Por la capacidad de infección del virus del dengue, el diagnóstico es amplio y varia con la evolución de la enfermedad. El incremento de la temperatura y las lluvias de la época son los factores ambientales principales para la reproducción del mosquito transmisor (Aedes aegypti), y el aumento de casos de dengue. Objetivos: Realizar un estudio transversal-retrospectivo de los casos de dengue en el departamento de La Paz - Bolivia, durante el periodo de enero de 2020 hasta febrero de 2023. Materiales y Métodos: De las bases obtenidas del Laboratorio de Virología- INLASA, se analizaron variables como el número de casos positivos de cada gestión, la distribución de los casos positivos según el lugar probable de infección tanto por departamento como por provincia, la variación temporal de los casos y el serotipo prevalente por gestión, y la distribución de casos positivos por género y grupo etario, en este trabajo se realizó un estudio transversal-retrospectivo. Resultados: Durante las cuatro gestiones analizadas el número total de casos notificados fue de 2143, detectando 1184 (55.2%) positivos. Señalando como lugar probable de infección en gran parte la provincia de Sud Yungas. Con respecto a la variación temporal presentó un mismo comportamiento en tres gestiones. Prevaleció en tres gestiones el serotipo DENV 1 sobre DENV 2, observando un aumento de serotipo DENV 2 hasta febrero del 2023. Además, el grupo atareo más afectado con dengue oscila entre los 10 a 39 años, no encontrando diferencia significativa entre género masculino y femenino. Conclusiones: Este estudio revela que el dengue es un problema de salud pública no solo del oriente del país sino también de las zonas tropicales del departamento de La Paz. Es necesario el diagnóstico rápido y efectivo; realizar la tipificación del virus y el llenado correcto de fichas epidemiológicas para un mejor control virológico.

Background: Dengue has become a serious problem in public health in Bolivia. Due the infection capacity of dengue virus, the diagnosis is broad and varies with the evolution of the disease. The increase of temperature and rain season are the main environmental factors of reproduction in the transmitting mosquito (Aedes aegipty), and the increase in dengue cases. Objectives: To carry out a retrospective crossover study of dengue cases in La Paz Department - Bolivia, during the period from January 2020 to February 2023. Materials and Methods: From databases obtained from INLASA Virology Laboratory during periods 2020, 2021, 2022 and the beginnings of 2023, variables such as number of positive cases from each year, distribution of positive cases according to the probable place of infection were obtained and analyzed, by department and by province; the temporal variation of the cases and the prevalent serotype by period, and finally distribution of positive cases by sex group and age group. Its make a retrospective crossover study. Results: During the four analyzed periods, within the total number of 2143 reported cases, there were 1184 (55.2%) of positive cases for Dengue. On the other hand, the department of La Paz (86.3%) is indicated as the probable place of infection, with Sud Yungas province (municipalities La Asunta and Palos Blancos) being the places with the most positive cases. The temporal variation in suspected and confirmed cases has presented the same behavior in three years. DENV 1 serotype predominated over DENV 2 in three years, observing an increase in DENV 2 serotype until February 2023. In addition, the age group most affected by dengue ranges from 10 to 39 years, finding no significant difference between masculine and feminine gender. Discussions: An increase in cases between months of February and April, coinciding with rain season in Bolivia. Due to the climate in the tropical areas of the department, there is a greater number of positive cases in those areas. Conclusions: This study reveals that Dengue is a public health problem not only in eastern part of the country but also in tropical areas of La Paz department. A quick and effective diagnosis is necessary; to carry out the typing of the virus and the correct filling out of epidemiological files for better virological control.

Prueba de microneutralización para la detección de anticuerpos contra el virus dengue serotipo 2

Objetivo: Optimizar la prueba de microneutralización (MNT) para detección de anticuerpos neutralizantes contra el virus dengue serotipo 2 (DENV-2) en la línea celular Vero-76. Materiales y métodos: Se evaluaron diferentes concentraciones celulares (0.6 x105 cel/mL, 0.9 x105 cel/mL, 1.2 x105 cel/mL), porcentajes de 2 %, 3 % y 4 % de suero bovino fetal (SBF), número de pasajes del stock de virus y los días de incubación. La semilla viral se confirmó por RT-qPCR. El DENV-2 se propagó realizando 5 pasajes en células Vero-76, seguidamente se tituló el virus en placas de 96 pozos y se evaluaron 2 métodos de infección celular: monocapa y células en suspensión, además se determinó el día óptimo de coloración de las células. Obtenidos los resultados, se procesaron mediante MNT para DENV-2 las siguientes muestras: 5 sueros negativos a DENV-2 y YFV (Virus de la Fiebre Amarilla), 5 sueros negativos de anticuerpos a DENV-2 y positivos de anticuerpos a YFV y 5 sueros positivos de anticuerpos a DENV-2 seleccionados mediante la prueba de neutralización por reducción de placas (PRNT). Resultados: El método óptimo para MNT utilizó células en suspensión (0.9 x 105 cel/mL), 2 % de SBF y semilla viral pasaje 5. La mínima dilución capaz de diferenciar una muestra positiva a DENV-2 fue 1:40 y el tiempo de incubación para la MNT para DENV-2 fue de 10 días. Conclusión: La MNT con el método de células en suspensión y medio de cultivo con 2 % de SBF permite detectar anticuerpos neutralizantes IgG contra DENV-2 con resultados confiables, pudiendo analizar un mayor número de muestras con ahorro de materiales.

Objective: To optimize the microneutralization test (MNT) for the detection of neutralizing antibodies against serotype 2 of dengue fever virus (DENV-2) in a Vero-76 cell line. Materials and methods: Different cell concentrations were assessed (0.6 X 105 cells/mL, 0.9 X 105 cells/mL, and 1.2 x 105 cells/mL) with 2%, 3%, and 4% fetal bovine serum, virus stock passage number, and incubation days. Viral particles were confirmed using RT-qPCR. DENV-2 disseminated with 5 passages in Vero-76 cells, then, the virus was titrated in 96-well plaques, and two methods for cell infection were evaluated: single layer, and suspended cells. Also, the optimum day for cell staining was determined. Once results were obtained, the following samples were processed using MNT for DENV-2: five sera negative for DENV-2 and yellow fever virus (YFV), five sera negative for antibodies against DENV-2 and positive for antibodies against YFV, and five sera positive for antibodies against DENV-2 that were selected using the plate reduction neutralization test. Results: The optimum method for MNT used suspended cells (0.9 X 105 cells/mL), 2% fetal bovine serum, and viral particles at the 5th passage. The minimal dilution able to differentiate a positive sample for DENV2 was 1:40, and the MNT incubation time for DENV-2 was ten days. Conclusion: MNT with the cell suspension method and a culture medium with 2% fetal bovine serum allows the detection of IgG neutralizing antibodies against DENV-2 with reliable results, so that larger sample sizes may be assessed, saving materials to be used.

Clinical Signs of Seasonal Disease Dynamics in Calves Caused by Rotavirus and Coronavirus Infections

The study of animal diseases increases the relevance of the livestock industry, which is the main leading component of the strategy for the development of agriculture in Azerbaijan. An important roleour country. Their research is critical in the implementation of measures to combat rotavirus and coronavirus infections in infant calves. The primary goal of this study was to investigate the seasonal dynamics of accompanying diarrhea in calves caused by rotavirus and coronavirus infection. The research was carried out on farms located in the northwestern region of the Azerbaijan republic. Fecal samples were used as material and tested by chromatographic immunoassay for the qualitative detection of rotavirus and coronavirus antigen. The study revealed that the clinical signs of diarrhea in calves caused by rotavirus and coronavirus infections in farms located in the northwest region of the country are relatively similar. However, there was a relatively higher incidence of rotovirus infection, and mortality relative to coronavirus was at a lower level. The occurrence of secondary pneumonia in patients with coronavirus was noted as one of the main clinical signs. The study showed that the trend of infection and death from both diseases changes in different seasons of the year, which from season to season and, as a result, becoming massive causes serious damage to farms, becoming widespread in spring, autumn, and winter.

Etiological characteristics of Vibrio parahaemolyticus strains isolated from foodborne outbreaks in Zhongshan in 2019 - 2021 / 公共卫生与预防医学

Objective To investigate the etiological characteristics of food poisoning isolates of Vibrio parahaemolyticus (VP) from 2019 to 2021 in Zhongshan City. Methods A total of 37 strains of Vibrio parahaemolyticus isolated from 8 food poisoning incidents in Zhongshan City from 2019 to 2021 were collected, including 1 residual food isolate and 36 human isolates. The genetic correlation of Vibrio parahaemolyticus food poisoning isolates in this region was analyzed by serological typing, virulence gene detection (TLH, TDH, and TRH), drug sensitivity test, pulsed field gel electrophoresis (PFGE) and multipoint sequence typing (MLST). Results The 37 strains of Vibrio parahaemolyticus were divided into 4 serotypes: O3:K6, O10:K4, O4:K8, and O4:KUT. The tdh+ and trh- were the main virulence genotypes, accounting for 97.30% (36/37). The drug resistance rate of cefazolin was 40.54% (15 strains R, 22 strains I), and no multidrug-resistant strains were found. The 37 VP strains were divided into 23 PFGE types and 6 cluster groups, with correlation coefficients ranging from 60.4%-100%. The multipoint sequencing typing showed that the 37 VP strains were divided into 9 ST types and 3 complex groups, of which ST3 type was the main type (23 strains, 62.1%). Conclusion This study has found that the dominant virulence types of Vibrio parahaemolyticus food poisoning isolates in Zhongshan City from 2019 to 2021 are tdh+ and trh-, and 37 representative strains can be divided into 6 PFGE clusters and 9 ST types with MLST type being mainly ST3. This study has identified the rare serotype O10:K4 which has caused an increase in the proportion of food poisoning events, suggesting that we should strengthen detection and be alert to the risk of continued local epidemics of new rare serotype strains.

Analysis of Salmonella contamination and pathogenic characteristics in raw poultry meats in Jiading District， Shanghai in 2021 / 上海预防医学

ObjectiveTo investigate the contamination status， serotype distribution and drug resistance of Salmonella in retail poultry in Jiading District， Shanghai. MethodsFour types of poultry （chicken， duck， goose and pigeon） have been sampled from commercial markets. Salmonella contamination has been isolated and identified using serotype analysis. Furthermore， resistance of isolated Salmonella strains towards 16 commonly used antibiotics has been determined. ResultsA total of 60 Salmonella strains were isolated from 80 poultry samples. The detection rates of Salmonella in pigeon， goose， duck and chicken were 86.67%， 81.82%， 72.73% and 59.38%， respectively. Contamination status has been categorized by storage conditions. Lowest detection rate （65.63%） has been noted in poultry samples under refrigeration storage. The majority serotypes of Salmonella have been revealed as Salmonella typhimurium， Salmonella enteritidis and Salmonella corvallis. Relatively higher drug resistance was discovered with tetracycline， nalidixic acid， ampicillin and chloramphenicol， with drug resistance rate of 60.00%， 58.33%， 50.00% and 48.33%， respectively. Low drug resistance was revealed with cefotaxime. In addition， these Salmonella strains were completely sensitive to imipenem. Significant difference in drug resistance was identified across the types of poultry or Salmonella serotypes. The 11.67% of Salmonella strains were non-resistant to any tested drugs. Multi-drug resistant strains accounted for 46.67% of isolated strains， which were resistant to 13 different antibiotics. Ampicillin-tetracycline or chloramphenirol-cefazolin drug resistance pattern suggested that the Salmonella strain was multi-drug resistant. ConclusionSalmonella contamination remains high in retail poultry in Jiading District， Shanghai. Drug resistance to antibiotics is increasing. Therefore， monitoring and control of Salmonella should be strengthened.

Serotypes and drug resistance of non-typhoidal Salmonella in Zhengzhou City / 预防医学

Objective@#To investigate the serotypes and drug resistance of non-typhoidal Salmonella in Zhengzhou City, so as to provide insights into prevention and control of non-typhoidal Salmonella infections. @*Methods@#Salmonella isolates were collected from diarrheal patients in Zhengzhou municipal sentinel hospitals from 2017 to 2021. Salmonella serotypes were identified using slide agglutination test and soft agar colony formation assay, and antimicrobial susceptibility test was performed using the broth micro-dilution method. @*Results@# Five serogroups and 37 serotypes were identified among 446 non-typhoidal Salmonella isolates, with S. enteritidis (210 isolates, 47.09%) and S. typhimurium (133 isolates, 29.82%) as dominant serotypes. Non-typhoidal Salmonella showed high resistance to ampicillin (79.60%), ampicillin/sulbactam (58.74%), naphthyric acid (56.05%), tetracycline (54.26%) and doxycycline (54.04%), respectively. There were 290 multidrug-resistant Salmonella isolates (65.02%), and the multidrug resistance rates were 70.48% for S. enteritidis and 67.67% for S. typhimurium, respectively. @*Conclusions @#Multiple serotypes of non-typhoidal Salmonella were identified in Zhengzhou City from 2017 to 2021, with S. enteritidis and S. typhimurium as dominant serotypes. Widespread drug resistance and multidrug resistance was seen in non-typhoidal Salmonella.

Virulence associated characteristics and drug resistance of Klebsiella pneumoniae isolated from patients living in Zhongjiang county of Sichuan province / 中国基层医药

Objective:To investigate the distribution characteristics of virulence-related phenotypes/genotype, capsular serotype, drug resistance phenotypes, and sequence typing (ST) of Klebsiella pneumoniae in patients living in Zhongjiang county, improve clinical understanding, and provide evidence for the prevention and control of bacterial drug resistance and clinical rational drug use. Methods:The data of 135 strains of Klebsiella pneumoniae isolated from patients who received treatment in Zhongjiang County People's Hospital from July to December 2019 were retrospectively analyzed. Bacterial identification and drug sensitivity testing were performed using the WalkAway-40Plus automated microbiology system. Strains with a high viscosity phenotype were identified using wire drawing experiments. Hypervirulence-associated capsular serotype and virulence genes were verified by polymerase chain reaction. ST of Klebsiella pneumoniae strain was identified using multilocus sequence typing. Results:Strains with a high viscosity phenotype were identified in 50.4% of the 135 strains. 54.1%, 54.8%, and 54.1% of the strains were positive for virulence genes iucA, iroN, rmpA. The proportion of strains with capsular Serotype K1 or K2 was 11.9% and 15.6%, respectively. A total of 65 kinds of ST were identified, with ST23 and ST37 being the most common, accounting for 11.1% and 6.7%, respectively. The resistance rate of the strains to 16 kinds of antibiotics was 0.0%-25.2%, and the resistance rate to Carbapenem antibiotics, Amikacin, and Tigecycline was less than 1%. The positive rate of virulence gene of strains with a high viscosity phenotype was significantly higher than that of strains without a high viscosity phenotype ( P < 0.001), and its resistance rate to Cephalosporin was significantly lower in strains with a high viscosity phenotype than that in strains without a high viscosity phenotype ( P < 0.001). Conclusion:Klebsiella pneumoniae in Zhongjiang County is characterized by "high virulence and low drug resistance". It is necessary to continuously monitor the changes in the virulence and drug resistance of Klebsiella pneumoniae in Zhongjiang County, Sichuan Province, and be alert to the rapid dissemination of highly virulent strains.

Dose-response relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children / 中国当代儿科杂志

OBJECTIVES@#To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines.@*METHODS@#The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage.@*RESULTS@#The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates.@*CONCLUSIONS@#There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.

Serotypes and drug resistance of salmonella in commercial food in Pudong New Area from 2020 to 2022 / 上海预防医学

ObjectiveTo understand the serotype distribution and drug resistance of salmonella contaminated in commercially available food. MethodsSalmonella detection， including the serotypes， was conducted in food products sold in Pudong New Area from 2020 to 2022. The antimicrobial susceptibility test of 15 antibiotics was conducted by the broth microassay. ResultsA total of 118 salmonella strains were detected in 2 497 pieces of food， with a total detection rate of 4.7%. The dominant detection categories were poultry meat， livestock meat and aquatic products. The 118 salmonella strains could be divided into 24 serotypes， Salmonella enteritidis （26.4%）， Salmonella Typhimurium （16.2%） and Salmonella delpy （14.4%） were the main dominant types. Salmonella had the highest resistance rate to ampicillin （63.6%）， followed by tetracycline， chloramphenicol， cotrimoxazole and nalidixic acid. Among the three dominant serotypes， the multidrug resistance rate of Salmonella typhimurium was the highest （89.5%）， followed by Salmonella delpy （70.6%） and Salmonella enteritidis （61.3%）. ConclusionLivestock， poultry meat， and aquatic products are seriously contaminated by salmonella with diverse serotypes. The livestock meat is mainly contaminated by Salmonella typhimurium and Salmonella delpy， and the poultry meat is mainly contaminated by Salmonella enteritidis. The drug resistance spectrum is wide and the multi-drug resistance rate is high. Different from the livestock and aquatic isolates， poultry meat-derived strains have high tolerance to ampicillin， nalidixic acid and polymyxin， and carry certain potential food safety risks.

Serotipos y resistencia antimicrobiana de Streptococcus pneumoniae en población pediátrica china: una revisión de alcance

Esta revisión tuvo como propósito explorar la distribución de serotipos y la resistencia antimicrobiana de Streptococcus pneumoniae en la población pediátrica de China a partir de literatura publicada en los últimos seis años. Se realizó una revisión de alcance a partir de PubMed y dos bases de datos de China: CNKI y WanFang Data. Del total de 196 artículos extraídos, se seleccionaron 14 estudios para esta revisión. Hay 13 artículos que analizan la distribución de serotipos de Streptococcus pneumoniae; los serotipos más frecuentemente registrados son: 19F, 19A, 23F, 14 y 6B. Hay 11 artículos que analizan la resistencia antimicrobiana de Streptococcus pneumoniae, la prevalencia de no susceptibles a la penicilina se encuentra en el rango de 0 % a 95,7 %. Los aislados son muy resistentes a eritromicina, clindamicina, tetraciclina y trimetoprima-sulfametoxazol; son resistentes a penicilina en meningitis neumocócica pero son sensibles a penicilina en otras enfermedades neumocócicas, además, son muy sensibles a levofloxacina, vancomicina y Linezolid. Se concluye que la vacuna antineumocócica conjugada 13 tiene alta cobertura en los serotipos de Streptococcus pneumoniae en los niños de China continental, por eso se recomienda su inclusión en el programa de vacunación infantil; al mismo tiempo, se debe tener en cuenta la aparición de la sustitución de serotipos. Por eso, se deben incluir más pacientes pediátricos o niños en las investigaciones, especialmente los menores de cinco años. Es necesaria una vigilancia de alta calidad a largo plazo sobre la distribución de serotipos y resistencia antimicrobiana de Streptococcus pneumoniae para el desarrollo de la prevención de enfermedades neumocócicas.

This review aimed to explore the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in the Chinese pediatric population based on literature published in the last six years. A scoping review was performed using PubMed and two Chinese databases: CNKI and WanFang Data. Of the total of 196 articles extracted, 14 studies were selected for this review. There are 13 articles that analyze the distribution of Streptococcus pneumoniae serotypes, the most frequently registered serotypes are: 19F, 19A, 23F, 14 and 6B. There are 11 articles that analyze the antimicrobial resistance of Streptococcus pneumoniae, the prevalence of non-susceptible to penicillin is in the range of 0% to 95.7%. Isolates are highly resistant to erythromycin, clindamycin, tetracycline, and trimethoprim-sulfamethoxazole; they are resistant to penicillin in pneumococcal meningitis but are sensitive to penicillin in other pneumococcal diseases, in addition, they are very sensitive to levofloxacin, vancomycin and Linezolid. It is concluded that the pneumococcal conjugate vaccine 13 has high coverage in Streptococcus pneumoniae serotypes in children from mainland China, therefore its inclusion in the childhood vaccination program is recommended; at the same time, the occurrence of serotype substitution should be taken into account. Therefore, more pediatric patients or children should be included in research, especially those under five years of age. Long-term, high-quality surveillance of the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae is necessary for the development of pneumococcal disease prevention.

Dengue Serotype Prevalence and Laboratory Profile Correlation in a Tertiary Care Hospital in Gandhinagar

Background: Dengue fever and dengue haemorrhagic fever currently rank highly among the newly emerging infectious diseases and are the most important arboviral disease worldwide. Dengue virus can be distinguished by both serological and molecular methods. This study was aimed at analysing the prevalence and laboratory dynamics of the four dengue serotypes in tertiary care patients attending GMERS Medical College Gandhinagar. Material & methods: This study was an observational retrospective study. A total 105 samples were tested for Dengue serotyping by RT-PCR. Results: Among positive patients Dengue virus serotype-2 was the most common serotype 94 (89%) followed by DENV3 7(6%) and DENV4 2(2%). Co-infection with DENV 2/4 was 2(2%). A higher prevalence of dengue haemorrhagic fever was noted in serotype 2 compared to serotypes 3, 4, and coinfection. Thrombocytopenia was present in all serotypes of infection. There was a significant difference in the disturbance of liver function in DENV2, as compared to others serotype. Dengue serotype 2 was very common in rural areas, while dengue serotype 3 was seen in the urban Gandhinagar zone. Discussion: Dengue is the most extensively spread mosquito-borne disease. As per previous studies most common prevalent and severity of serotype wasDENV2, however in our study we were able to identify DENV3, DENV4 and confection with serotypes (DENV2 & DENV4).

Analysis of salmonella drug resistance in poultry sold in Jiading District from 2019 to 2020 / 上海预防医学

ObjectiveTo investigate the contamination situation， serotype distribution and drug resistance of salmonella in poultry sold in Jiading District， Shanghai. MethodsBetween 2019 and 2020， four types of poultry meat （chicken， duck， goose and pigeon） were sampled from markets， and potential salmonella contamination was isolated and identified via serotyping. Furthermore， resistance detection of isolated salmonella to 13 commonly-used antibiotics was conducted. ResultsA total of 32 salmonella strains were isolated from 156 commercial poultry samples. No salmonella was identified in pigeon samples， while the most severe contamination was detected in goose samples， with a detection rate of 28.00%. Contamination situation was categorized with different storage conditions. The lowest detection rate of 12.90% was noted under cold storage， while the highest rate of 26.67% was detected under frozen condition. The major serotypes of salmonella were Salmonella typhimurium， Salmonella enteritidis and Salmonella Argonne. Relatively higher drug resistance was detected with nalidixic acid and tetracycline， with drug resistance rate of 59.38% and 40.63%， respectively. Low drug resistance was detected with cephalosporins， and no drug resistance was detected with imipenem. Significant difference in drug resistance was noted in the serotype of Salmonella isolated from meat of chicken， duck and goose. Three major salmonella strains had different drug resistance. 21.88% （7/32） of salmonella strains were non-resistant to any tested drugs. Multi-drug resistant strains accounted for 31.25% （10/32） of the isolated strains. At most， salmonella was resistant to 11 kinds of different antibiotics. ConclusionThere is a significant difference in the contamination situation and drug resistance of Salmonella isolated from four types of poultry meat sold in Jiading District， Shanghai. It is strongly recommended that different supervision strategies and management upon classification be implemented.

Analysis of serotype distribution and antibiotic resistance of Haemophilus influenzae in hospitalized children / 中华实用儿科临床杂志

Objective:To explore the serotype, antibiotic resistance and β-lactamase gene of Haemophilus influenzae strains isolated from hospitalized children, thus providing reference for clinical diagnosis and treatment. Methods:A total of 148 Haemophilus influenzae strains collected from January 2016 to December 2018 in hospitalized children of Children′s Hospital, Capital Institute of Pediatrics were retrospectively analyzed.The serotype and genotype of Haemophilus influenzae strains were examined by slide agglutination test and PCR, respectively.The sensitivity of isolates to Ampicillin and other antimicrobials was detected by the E-test and disk diffusion methods.The β-lactamase phenotype was tested by nitrocefin disk method.The carrying of β-lactamase gene TEM-1 and ROB-1 were detected by PCR.The drug resistance rate was compared by χ2 test. Results:All the 148 strains were nontypeable Haemophilus influenzae (NTHi), and capsular gene was not amplified.The rate of resistance to Ampicillin, Ampicillin/Sulbactam, Cefuroxime, and Azithromycin were 68.9%(102/148 strains), 40.5%(60/148 strains), 53.4%(79/148 strains) and 56.1%(83/148 strains), respectively.The Haemophilus influenzae isolates showed the highest resistance rate to Trimethoprim-sulfamethoxazole, which was up to 91.9%(136/148 strains). The sensitive rate of isolates to Ceftriaxone, Meropenem and Levofloxacin were all 100.0%(148/148 strains). The prevalence of β-lactamase was 64.8%(96/148 strains) in Haemophilus influenzae and the genotype was TEM-1.The drug resistance rates of β-lactamase positive strains to Ampicillin, Ampicillin/Sulbactam and Azithromycin were significantly higher than those of other strains( χ2=123.222, 27.973, 70.273, all P<0.01). Conclusions:The most prevalent serotype of Haemophilus influenzae is NTHi in children. Haemophilus influenzae carried TEM-1 gene had a high positive rate of β-lactamase production, which was the main mechanism of drug resistance to Ampicillin.Ceftriaxone and Meropenem were the most active agents against Haemophilus influenzae.

The value of multiplex PCR method based on capillary electrophoresis in detecting common serotypes of respiratory adenovirus infection in children / 中华实用儿科临床杂志

Objective:To establish a common method for detecting serotypes of respiratory adenovirus, and to detect the main serotypes of respiratory human adenovirus (HAdV) infection in children in Wenzhou area.Methods:A multiplex PCR method based on capillary electrophoresis was developed to detect 12 common serotypes of respiratory adenovirus.A total of 1 059 children with acute respiratory infection who were admitted to Yuying Children′s Hospital Affiliated to Wenzhou Medical University from January 2018 to December 2019 with positive infection of HAdV detected by the direct immunofluorescence method were recruited and retrospectively analyzed.Multiplex PCR was performed to determine 12 serotypes of respiratory adenovirus, including HAdV-1, 2, 3, 4, 5, 7, 14, 21, 37, 40, 41 and 55.Meanwhile, some samples were randomly selected to examine the consistency in the detection result by the first-generation sequencing method.Results:A total of 1 059 specimens of respiratory secretions with positive HAdV antigen were collected.Detected by multiplex PCR method, 947 cases (89.4%) were positive for 1 serotype, 13 cases (1.2%) were mixed infection with 2 serotypes, and 24 cases (2.3%) were negative.In addition, 75 cases(7.1%) were positive but could not be serotyped.Among the 947 children with the positive infection of a single serotype, 415 cases (43.8%) were HAdV-3 in subgroup B, 318 cases(33.6%) were HAdV-7, 12 cases (1.2%) were HAdV-55, 2 cases (0.2%) were HAdV-21, 108 cases (11.4%) were HAdV-2 in subgroup C, 70 cases (7.4%) were HAdV-1, 16 cases(1.7%) were HAdV-5, and 6 cases(0.6%) were HAdV-4 in subgroup E. HAdV-14, HAdV-37, HAdV-40 and HAdV-41 were not detected.A total of 51 positive samples of HAdV infection detected by multiplex PCR were randomly selected to compare with the detection result by the first-generation sequencing, which were all consistent.Conclusions:This study successfully established a multiplex PCR based on capillary electrophoresis in diagnosing common serotypes of respiratory adenovirus infection in children.HAdV-3, HAdV-7 of subgroup B and HAdV-2 and HAdV-1 of subgroup C were the main serotypes of respiratory adenovirus infection in children of Wenzhou area.HAdV-14, HAdV-37, HAdV-40 and HAdV- 41 were not detected.

Construction of recombinant adenovirus expressing capsid protein of serotype O foot-and-mouth disease virus and analysis of its immunogenicity / 生物工程学报

In order to construct a recombinant replication deficient human type 5 adenovirus (Ad5) expressing a foot-and-mouth disease virus (FMDV) capsid protein, specific primers for P12A and 3B3C genes of FMDV-OZK93 were synthesized. The P12A and 3B3C genes were then amplified and connected by fusion PCR, and a recombinant shuttle plasmid pDC316-mCMV-EGFP-P12A3B3C expressing the FMDV-OZK93 capsid protein precursor P12A and 3B3C protease were obtained by inserting the P12A3B3C gene into the pDC316-mCMV-EGFP plasmid. The recombinant adenovirus rAdv-P12A3B3C-OZK93 was subsequently packaged, characterized and amplified using AdMaxTM adenovirus packaging system, and the expression was verified by infecting human embryonic kidney cell HEK-293. The humoral and cellular immunity levels of well-expressed and purified recombinant adenovirus immunized mice were evaluated. The results showed that rAdv-P12A3B3C-OZK93 could be stably passaged and the maximum virus titer reached 1×109.1 TCID50/mL. Western blotting and indirect immunofluorescence showed that rAdv-P12A3B3C-OZK93 expressed the FMDV-specific proteins P12A and VP1 in HEK-293 cells. In addition, the PK cell infection experiment confirmed that rAdv-P12A3B3C-OZK93 could infect porcine cells, which is essential for vaccination in pigs. Comparing with the inactivated vaccine group, the recombinant adenovirus could induce higher FMDV-specific IgG antibodies, γ-IFN and IL-10. This indicates that the recombinant adenovirus has good immunity for animal, which is very important for the subsequent development of foot-and-mouth disease vaccine.