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.

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.

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.

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.

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.

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.

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).

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.

Serotype distribution and drug resistance of Streptococcus pneumoniae in hospitalized patients in Yulin, Guangxi / 中国热带医学

@#Abstract: Objective　To analyze the serotype distribution, drug resistance rate and drug resistance gene carrying of Streptococcus pneumoniae isolates in hospitalized patients, and evaluate the coverage of the vaccine to the serotype of Streptococcus pneumoniae in this area, so as to provide reference for the rational use of antibiotics in clinic. Methods　A total of 150 strains of non-repetitive Streptococcus pneumoniae isolated from inpatients from January 2015 to December 2019 were collected for serotyping and antimicrobial sensitivity test. The carrying rates of pbp2b, ermB and tetM were detected by PCR. Results　The PCR classification rate of 150 strains of Streptococcus pneumoniae was 93.1%, and the classification rate of capsular swelling test was 100%, and a total of 19 serotypes were divided, mainly 19F and 6B. Children's serotypes were predominantly 19F, 6B, and 15A; adult serotypes were predominantly 19F, 14, and 23F. The coverage rates of the PCV7, PCV10, PCV13 and PPV23 vaccines were 36.8%, 42.1%, 57.9% and 68.4%, respectively. Strains with serotypes of 19F, 6B, 3, and 23F had higher rates of resistance to antimicrobials. The sensitivity of Streptococcus pneumoniae to penicillin was greater than 96.0%. Antimicrobials with significant differences in resistance rates between invasive and non-invasive strains were penicillin, moxifloxacin, and levofloxacin. The percentage of strains carrying both ermB and tetM resistance genes was 96.0%, and the concordance rate between pbp2b, ermB and tetM resistance genes and the resistance phenotype was >98.0%. A total of 10 multi-resistance combinations were detected, with a multi-resistance rate of 62.6%, and the multi-drug resistance pattern of Streptococcus pneumoniae was mainly concentrated in the 19F and 6B serotypes. Conclusion　There are significant age differences in the serotypes of Streptococcus pneumoniae in this area. The vaccine currently used has low coverage in this region and therefore offer limited protection to the population. The drug resistance rates of Streptococcus pneumoniae varied significantly among serotypes. Erythromycin and tetracycline are not recommended for clinical treatment of Streptococcus pneumoniae. Penicillin can still be used as the first choice for clinical treatment of Streptococcus pneumoniae infection.

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.

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.

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.

Salmonella enterica serotypes from human and nonhuman sources in Sao Paulo State, Brazil, 2004-2020

ABSTRACT Salmonellosis ranks among the most frequently reported zoonosis worldwide and is often associated with foodborne outbreaks. Since the 1950s, the distribution of Salmonella serotypes in Sao Paulo State, Brazil, has been documented and periodically reported. In this study, we updated the data on the distribution of Salmonella serotypes received in our reference laboratory, isolated from human infections and nonhuman sources, from 2004 to 2020. In that period, a total of 9,014 Salmonella isolates were analyzed, of which 3,553 (39.4%) were recovered from human samples, mainly of stool (65%) and blood (25.6%), and 5,461 (60.6%) were isolated from nonhuman origins, such as animals (47.2%), food (27.7%) and animal environments (18.6%). In human isolates, a total of 104 serotypes were identified and the most frequent ones were Enteritidis, Typhimurium, S . I. 4,[5],12:i:-, Dublin and Typhi. A consistent reduction of the Enteritidis proportion was observed over the years. Among the 156 serotypes identified in isolates with nonhuman origins, Enteritidis, Mbandaka, Typhimurium, Agona and Anatum were ranked as the top five Salmonella serotypes; in more recent years, S . Heidelberg has increased in frequency. Although with different proportions, the top 10 prevalent serotypes were identified in both human and nonhuman origins, underscoring the role of animals, food products and environment as reservoirs of Salmonella with potential to cause human salmonellosis.

Epidemiological characteristics and drug resistance of Salmonella isolated from diarrhea patients in Jiading District of Shanghai / 上海预防医学

Objective:To analyze the epidemiological characteristics and drug resistance of Salmonella in patients with food-borne diarrhea in Jiading District. Methods:From January 2018 to December 2019， feces or anal swabs of patients were collected from five hospitals in monitoring sites， and the drug sensitivity test was conducted using the micro broth dilution method. Results:The total detection rate of Salmonella was 7.85% （142/1 810）， and the detection rates of 0-6， 7-17， 18-40， 41-65 and over 65 years old were 8.97% （13/145）， 6.94% （5/72）， 7.58% （75/989）， 8.69% （41/472） and 6.06% （8/132）， respectively. Salmonella rosenbergii was a new dominant serotype in this area. Many strains were resistant to the third and fourth generation cephalosporins， fluoroquinolones and even azithromycin. The sensitivity rate of Salmonella typhimurium to cefotaxime and cefepime was 84.85%， and the resistance rate to fluoroquinolones was 12% to 16%. The mediating rates of Salmonella and Salmonella enteritidis to fluoroquinolones were 56% to 60% and 95.56%， respectively. Conclusion:The detection rate of Salmonella infection is high in all age groups. It is necessary to pay more attention to new dominant serotypes. Salmonella typhimurium is highly resistant to the third and fourth generation cephalosporins and fluoroquinolones， while the sensitivity of Salmonella， especially Salmonella enteritidis to fluoroquinolones has decreased significantly.

Serotype distribution of enteroviruses in child cases with influenza-like illness in Hangzhou city / 中华微生物学和免疫学杂志

Objective:To study the pathogenic spectrum of enterovirus (EV) in the samples of child influenza-like(ILI)cases in Hangzhou city .Methods:In 2019, 1 060 throat swab specimens of ILI cases were collected for serotyping of influenza virus and EVs by real-time RT-PCR. The positive rates of influenza virus and EV in spring, summer, autumn and winter were compared by chi-square test with SPSS16.0 software. Specific primers were synthesized and used to amplify the VP1 fragments of EV. PCR products were sequenced and the results were compared with the reference sequences by using Basic Local Alignment Search Tool (BLAST) to identify the serotypes of isolated EV. The clinical diagnoses of EV positive cases were classified and analyzed.Results:A total of 1 060 specimens were collected and 283(26.70%) were positive for influenza virus, 75(7.08%) were positive for EV, 3(0.28%)were positive for influenza virus and EV. The comparison of positive detection rate of spring, summer, autumn and winter showed that influenza virus were prevalent in winter and spring. EV were mostly popular in the summer months. VP1 sequences of 51 EV were successfully amplified and BLAST analysis revealed that these strains belonged to 10 serotypes, including five serotypes of EV-A species, four serotypes of EV-B species and one serotype of EV-D. The ten serotypes of EV, including coxsackievirus (CV)A2, A4, A5, A6, A9, A10, and echovirus (ECHO)7, ECHO11, ECHO18, and EV-D68 were obtained and the percentages of positive were 16.00%, 16.00%, 5.33%, 12.00%, 5.33%, 1.33%, 1.33%, 5.33%, 4.00% and 1.33%, respectively. The phylogram of EV VP1 sequence showed that 51 EV strains in Hangzhou had different degrees of variation compared with the reference strains. Acute upper respiratory tract infection was the main clinical diagnosis in EV positive children, with 44 cases (58.67%). Acute tonsillitis was followed by 14 cases (18.67%). Followed by herpetic pharyngitis, acute bronchitis, asthmatic bronchitis, pneumonia, accounting for 12.00%, 8.00%, 1.33%, 1.33%, respectively.Conclusions:EV causing influenza-like illness in children in Hangzhou in 2019 belonged to 10 serotypes, CVA2 and CVA4 were the predominant serotypes, and the positive rate of EV detection was higher in summer.

Analysis of serum and drug resistance levels between food source and human salmonella / 公共卫生与预防医学

Objective To analyze serotype distribution, drug resistance, quinolone resistance gene carrying status and genetic relationship of foodborne Salmonella and human Salmonella isolates in Changzhou from 2012 to 2018, to provide scientific basis for the prevention and control of Salmonella. Methods The serum type was identified by serum agglutination and liquid chip. The antibiotic sensitivity was determined by micro broth dilution method. The quinolone antibiotic resistance gene was determined by gene sequencing method. The multilocus sequence typing ( MLST ) typing was performed on quinolone-resistant Salmonella, and the genetic relationship was analyzed by BioNumerics 8.0. Results A total of 10 and 36 serotypes were detected in 46 foodborne Salmonella strains and 152 human Salmonella strains, respectively. The dominant serotypes were Indiana Salmonella and Salmonella typhimurium. Erythromycin resistance rate was the highest in both Salmonella strains, and the proportion of multidrug-resistant bacteria was 93.47 % ( 43 / 46 ) and 80.92 % ( 123 / 152 ), respectively. 38 strains of quinolone-resistant foodborne Salmonella GyrA subunit mainly occurred double mutations Asp87Asn, Ser83Phe, ParC subunit mainly occurred single mutation Ser80Arg, 119 strains of quinolone-resistant human Salmonella qnrS gene detection rate was higher, reached 68.1 % ( 81 / 119 ) ; The dominant ST types of quinolone-resistant Salmonella from two sources were ST17 and ST19, respectively. Conclusions The antibiotic sensitivity of the two Salmonella resistant strains from Changzhou was the same ; Synergistic drug resistance, but both quinolone resistance genemutations and carry inconsistent ; The ST type distribution of quinolone resistant strains isalso inconsistent, and the genetic relationship is far. It is suggested that the probability of Salmonella resistant bacteria infection caused by food transmission in our region is small, and the treatment of the two should be differentiated.