Emergence of macrolide-resistant Streptococcus pyogenes emm12 in southern Taiwan from 2000 to 2019

BackgroundGroup A Streptococcus (GAS) is an important pathogen causing morbidity and mortality worldwide. Surveillance of resistance and emm type has important implication to provide helpful information on the changing GAS epidemiology and empirical treatment.MethodsTo study the emergence of resistant GAS in children with upper respiratory tract infection (URTI), a retrospective study was conducted from 2000 to 2019 in southern Taiwan. Microbiological studies, including antibiotic susceptibility, were performed. GAS emm types and sequences were determined by molecular methods. The population was divided into two separate decades to analyze potential changes over time. The 1st decade was 2000–2009; the 2nd decade was 2010–2019. Multivariate analyses were performed to identify independent risk factors associated with macrolide resistance between these periods.ResultsA total of 320 GAS from 339 children were enrolled. Most of the children (75%) were under 9 years of age. The most common diagnosis was scarlet fever (225, 66.4%), and the frequency increased from 54.8% in the 1st to 77.9% in the 2nd decade (p < 0.0001). There was a significant increase in resistance to erythromycin and azithromycin from 18.1%, 19.3% in the 1st to 58.4%, 61.0% in the 2nd decade (p < 0.0001). This was associated with clonal expansion of the GAS emm12-ST36 which carrying erm(B) and tet(M) from 3.0% in the 1st to 53.2% in the 2nd decade (p < 0.0001).ConclusionsSignificant emergence of macrolide-resistant GAS emm12-ST36 in children supports the need for continuing surveillance and investigation for the clonal virulence.     

Distribution of emm types among group A streptococcal isolates from Serbia

This is the first study concerning the molecular epidemiology of group A streptococcus in Serbia and includes 145 isolates from patients with various infections during the period 2001–2007. The emm types, superantigen profile and susceptibility pattern were determined. Among 31 emm types identified, the most prevalent were emm6, emm12, emm1, and emm58. All isolates showed uniform antimicrobial susceptibility to all tested antibiotics, with the exception of tetracycline and erythromycin (41% and 0.7% resistant strains, respectively). Significant heterogeneity of emm types was found, with a high frequency of emm6 and emm58, as well as a considerable prevalence of tetracycline resistance, and a low level of macrolide resistance.     

Arrangement and number of clustered regularly interspaced short palindromic repeat spacers are associated with erythromycin susceptibility in emm12, emm75 and emm 92 of group A streptococcus

Clustered regularly interspaced short palindromic repeats (CRISPR) are composed of numerous repeat-spacer units and are considered a prokaryotic defence system against foreign nucleic acids. Since antibiotic-resistant genes are frequently encoded in foreign nucleic acids, the aim of this study was to test whether erythromycin susceptibility in group A streptococcus (<Streptococcus pyogenes) is associated with characteristics of CRISPR elements. Erythromycin susceptibility of 330 isolates collected between 1997 and 2003 was analysed. Among 29 emm types, emm12, emm75 and emm92 showed significant changes in erythromycin-resistance rates. By sequencing the spacers from two CRISPR loci, spacer contents in emm12, emm75 and emm92 strains were associated with erythromycin susceptibility. Strains with fewer spacers were more resistant to erythromycin. Moreover, in emm4 strains, which showed no significant change in their annual erythromycin-resistance rate, CRISPR type and number of spacers were not correlated with erythromycin susceptibility. These results highlight a novel association between CRISPR spacer content and erythromycin susceptibility in group A streptococcus.     

2010-2012年广州地区人冠状病毒及其亚型分布

目的了解2010—2012年广州地区发热呼吸道感染病人的冠状病毒（HCoV）流行状况和特点,为进一步了解人冠状病毒的流行规律及防控奠定基础。方法收集广州市2010—2012年5家哨点医院共3376例符合要求的发热同时伴随有呼吸道感染症状病人的咽拭子标本及相关临床信息,采用Real—timePCR方法检测冠状病毒的核酸并对其进行主要型别鉴定,从人群分布、月份分布及各型别发病率等方面进行分析。结果3376例发热伴有呼吸道感染症状的病例中,55例为冠状病毒阳性标本,检出率为1．63％。亚型0C43、229E和NL63阳性的标本分别为23、13和19例,阳性率分别为0．68％、0．39％和0．56％,其中SARS、HUKl及EMC亚型未检出。冠状病毒流行高峰为1月（5．33％）,不同月份之间发病率比较差异有统计学意义（xz=38．197,P〈0．01）;阳性率最高年龄组为60。93岁,检出率为2．6％。亚型OC43发病高峰为12—1月,与其他月份比较差异有统计学意义（xL30．054,P〈0．01）,检出率最高的年龄组为60～93岁（1．3％）;229E月分布较为分散,各月份间差异无统计学意义（x：=15．651,P〉0．05）,在各年龄组的分布呈不集中趋势;NL63流行高峰为6-9月,与其他月份比较差异有统计学意义（x2=5．801,P〈0．05）,检出率最高的年龄组为7～17岁（1．03％）。结论广州市2010—2012年冠状病毒流行高峰为1月份。老年组检出率最高;亚型中OC43阳性率最高,NL63次之,229E亚型阳性率最低;0C43流行高峰为冬季,老年组检出率较高;229E流行高峰及感染人群较为分散;NL63流行高峰为夏季,儿童青少年组检出率最高。     

Distribution of genotypes and antibiotic resistance genes among invasive Streptococcus agalactiae (group B streptococcus) isolates from Australasian patients belonging to different age groups.

Serotype distribution and antibiotic resistance (AR) among group B streptococci (GBS) affect GBS disease prevention strategies, but vary among patient groups. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was used to compare the distributions of GBS serotypes, serotype III subtypes and AR-associated genes among 666 invasive isolates from 663 patients, divided into five age groups: infants, early-onset (EO; 0-6 days) and late-onset (LO; 7-90 days); children (aged 3 months to 14 years); women of childbearing age (WCBA; aged 15-45 years); and other adults (males aged >15 years; females aged >45 years). Serotypes Ia and V and serosubtype III-1 accounted for 60% of infections. Serosubtype III-2, which corresponds to a virulent clone belonging to sequence type (ST)17, was relatively uncommon overall (7%), but was associated strongly with LO infant infections, in which it was significantly more common than in adult infections (25/104 (24%) vs. 9/392 (2%), p <0.0001) or in EO infections (25/104 (24%) vs. 14/155 (9%), p <0.005). Erythromycin resistance genes were found in 8% of all isolates (ermB 3%, ermA 2.5% and mefA/E 2%), in 11-15% of isolates of serotypes II and V and subtype III-1, but in none of the isolates of serosubtype III-2 (III-2, 0/49 vs. all others, 54/618 (9%), p <0.04). In summary, the virulent serosubtype III-2 was associated strongly with LO infant GBS infection, but was less likely than other serotypes or serosubtype III-1 to carry AR genes.     

Distribution of emm types and subtypes among noninvasive group A, C and G streptococcal isolates in western Norway

Characterization of the reservoir of beta-hemolytic streptococci in a community may shed light on the pathogenesis of severe infections caused by these bacteria. We used emm sequence typing to characterize group A streptococci (GAS), group C streptococci (GCS) and group G streptococci (GGS) in community isolates associated with noninvasive disease in western Norway. A total of 165 isolates during a 13-month period were examined. Skin and throat isolates accounted for 123 and 16, respectively, and the remaining 26 isolates were from other non-sterile sites. We identified 18 previously validated emm types and one novel subtype, emm11.7, among the 101 GAS isolates. The two predominant types, emm28 and 12, were found in 40.6% of the GAS isolates. Compared to other recent studies of noninvasive GAS infections from elsewhere in the world, we found a higher frequency of emm82 (5.9%) and emm87 (12.9%) and a lower frequency of emm1 (4.0%) and emm3 (4.0%). We found a different distribution of GAS emm types compared to a previous study from western Norway. Among the 64 isolates of GCS and GGS, 15 previously described emm types and four novel subtypes, stC1400.5, stCK401.3, stG6.3 and stG652.3, were found, stG6, stG643 and stG485 were the most prevalent types and accounted for 59.4% of the GCS and GGS isolates. The high proportion of skin isolates in the present study may indicate the existence of GAS, GCS and GGS strains with predominantly skin and soft tissue tropism in our community.     

2013~2018年乌鲁木齐市猩红热流行病学特征分析

目的 分析2013~2018年乌鲁木齐市猩红热疫情流行病学特征和规律,为制定防控措施提供科学依据。方法 采用描述性流行病学方法对乌鲁木齐市2013~2018年报告的猩红热病例进行分析。结果 2013~2018年乌鲁木齐市共报告猩红热病例6471例,发病率为30.74/10万。发病率排前三位的是天山区（37.26/10万）、经济开发区（34.11/10万）和沙区（32.48/10万）。发病高峰主要集中在5~6月份和11~12月份,发病年龄以3~8岁为主,发病人群主要以托幼机构儿童和小学生为主。结论 2013~2018年乌鲁木齐市猩红热发病率呈周期性波动,其中5~6月份和11~12月份为发病高峰期,主要集中在中心城区,以3~8岁年龄段的托幼机构儿童和小学生为主。因此需加强学校和托幼机构疫情的监测和防控,防止疫情暴发流行。     

天津市2019年住院散发急性胃肠炎患儿中诺如病毒感染分子流行病学特征分析

目的:了解天津市2019年散发急性胃肠炎患儿中诺如病毒(Norovirus, NoV)感染的分子流行病学特征。方法:收集2019年1—12月就诊于天津市儿童医院住院散发急性胃肠炎患儿的粪便标本3 116份,收集患儿临床资料和个人信息,采用实时荧光定量PCR方法对NoV进行初筛,应用反转录PCR方法对初筛阳性标本的聚合酶...     

Repeat exposure to group A streptococcal M protein exacerbates cardiac damage in a rat model of rheumatic heart disease

Rheumatic fever and rheumatic heart disease (RF/RHD) develop following repeated infection with group A streptococci (GAS). We used the Rat Autoimmune Valvulitis (RAV) model of RF/RHD to demonstrate that repetitive booster immunization with GAS-derived recombinant M protein (rM5) resulted in an enhanced anti-cardiac myosin antibody response that may contribute to the breaking of immune tolerance leading to RF/RHD and increased infiltration of heart valves by mononuclear cells. With each boost, more inflammatory cells were observed infiltrating heart tissue which could lead to severe cardiac damage. We also found evidence that both complement and anti-M protein antibodies in serum from rM5-immunized rats have the potential to contribute to inflammation in heart valves by activating cardiac endothelium. More importantly, we have demonstrated by electrocardiography for the first time in the RAV model that elongation of P–R interval follows repetitive boost with rM5. Our observations provide experimental evidence for cardiac alterations following repeated exposure to GAS M protein with immunological and electrophysiological features resembling that seen in humans following recurrent GAS infection.     

Assessment of Cpa,Scl1 and Scl2 in clinical group A streptococcus isolates and patients from north India: an evaluation of the host pathogen interaction

Group A streptococcus (GAS) infection remains a major concern due to multiple diseases including pharyngitis, impetigo, acute rheumatic fever (ARF) and rheumatic heart disease (RHD). It uses different adhesins and virulence factors like Cpa (collagen binding protein) and Scl (collagen-like protein) in its pathogenicity. Scl having similarities with human collagen may contribute to inducing autoimmunity in the host. Here we assessed gene expression, antibody titer of Cpa, Scl1 and Scl2 in both clinical GAS isolates (n = 45) and blood (n = 45) obtained from pharyngitis, ARF (acute rheumatic fever) and RHD respectively. Skin isolates (n = 30) were obtained from impetigo patients. The study revealed a total of 27 GAS emm types. Frequency of cpa, scl1, scl2 was high in ARF isolates. The antibody titer of these proteins was high in all isolates, and also in patients with pharyngitis and ARF. All isolates showed high binding affinity toward collagen I and IV, which further indicates a potential host pathogen interaction. Our study reflects a strong association of Cpa and Scls in early and post-GAS pathogenicity. However, the increased antibody titer of Scl1 and Scl2 during ARF may be attributed to a cogent immune response in the host.     

Predictors of self-reported depression in Korean children 9 to 12 years of age

PURPOSE: The aim of this study was to evaluate the relationships among various psychosocial factors, behavior problems, and depressive symptoms reported by parents, and to investigate self-reported depression in Korean children using a community sample. MATERIALS AND METHODS: The sample consisted of 1279 children between 9 and 12 years of age. The children were evaluated using the Korean version of the Child Behavior Checklist (K-CBCL) and the Child Depression Inventory (CDI). RESULTS: The average self-reported depression score as measured by the CDI was 12.34 (SD: 6.79), and a cut-off point of 19 identified approximately 14% of the children as depressed. The group difference was identified by the age at which younger children were found to have higher CDI scores. Univariate logistic regression analysis showed that the high-CDI group and the low-CDI group differed in all behavioral domains identified in the parent-reported subscales of the K-CBCL. Age and father's education level were also independently associated with the risk for childhood depression. In addition, results from the logistic regression analyses indicated that parental reporting of problem internalization, total behavior problems, and social competence were independent predictors of child depression not identified by the anxious/depressed subscale. CONCLUSION: It is believed that extensive behavioral problems reported by parents and several sociodemographic factors are related to childhood depression. However, parents tend to under-report depressive symptoms relative to what their own children report. Thus, clinicians must consider the self-reports of children related to depression in their diagnosis and intervention, because reports of depressive symptoms from children are more valid measures than those from parents.     

Distribution of varicella-zoster virus (VZV) wild-type genotypes in northern and southern Europe: Evidence for high conservation of circulating genotypes

Phylogenetic analysis of 19 complete VZV genomic sequences resolves wild-type strains into 5 genotypes (E1, E2, J, M1, and M2). Complete sequences for M3 and M4 strains are unavailable, but targeted analyses of representative strains suggest they are stable, circulating VZV genotypes. Sequence analysis of VZV isolates identified both shared and specific markers for every genotype and validated a unified VZV genotyping strategy. Despite high genotype diversity no evidence for intra-genotypic recombination was observed. Five of seven VZV genotypes were reliably discriminated using only four single nucleotide polymorphisms (SNP) present in ORF22, and the E1 and E2 genotypes were resolved using SNP located in ORF21, ORF22 or ORF50. Sequence analysis of 342 clinical varicella and zoster specimens from 18 European countries identified the following distribution of VZV genotypes: E1, 221 (65%); E2, 87 (25%); M1, 20 (6%); M2, 3 (1%); M4, 11 (3%). No M3 or J strains were observed.     

Hepatitis in Albanian children: molecular analysis of hepatitis A virus isolates

Hepatitis A is a common disease in developing countries and Albania has a high prevalence of this disease associated to young age. In spite of the occurrence of a unique serotype there are different genotypes classified from I to VII. Genotype characterisation of HAV isolates circulating in Albania has been undertaken, as well as the study of the occurrence of antigenic variants in the proteins VP3 and VP1. To evaluate the genetic variability of the Albanian hepatitis A virus (HAV) isolates, samples were collected from 12 different cities, and the VP1/2A junction amplified and sequenced. These sequences were aligned and a phylogenetic analysis performed. Additionally, the amino half sequence of the protein VP3 and the complete sequence of the VP1 was determined. Anti-HAV IgM were present in 66.2% of all the sera. Fifty HAV isolates were amplified and the analysis revealed that all the isolates were sub-genotype IA with only limited mutations. When the deduced amino acid sequences were obtained, the alignment showed only two amino acids substitutions at positions 22 and 34 of the 2A protein. A higher genomic stability of the VP1/2A region, in contrast with what occurs in other parts of the world could be observed, indicating high endemicity of HAV in Albania. In addition, two potential antigenic variants were detected. The first at position 46 of VP3 in seven isolates and the second at position 23 of VP1 in six isolates.     

Epidemiology of influenza in hospitalized children with respiratory tract infection in Suzhou area from 2016 to 2019

Influenza is a contagious respiratory disease and risks public health in China, and it has caused wide public concern in recent years. Immunocompromised patients, such as children and elderly people, suffer more severe influenza complication and some extreme cases are even life threatening. To identify the influenza characteristics and its correlation with various climatic and environmental pollution factors, we collected the reported influenza epidemic of hospitalized children in Children's Hospital of Soochow University from 2016 to 2019. Our results show that the main influenza virus subtypes are A/H1N1, A/H3N2, B/BV, and B/BY. We also identified the characteristics of the prevalent influenza virus subtypes in different months, seasons, years, and patients' age. Of all the influenza infected patients, the most susceptible groups are children over 3 to 5 years of age, and more cases are reported in winter than other seasons. We also found that influenza is also highly correlated with climatic and environmental pollution factors, and the autoregressive integrated moving average model is employed for the short-term influenza prediction in Suzhou city, which can provide scientific basis for the prevention and control of influenza and public health decision-making.     

2010-2012年北京地区儿童轮状病毒腹泻的流行病学研究

目的 调查北京友谊医院就诊儿童轮状病毒腹泻的流行状况.方法 收集北京友谊医院2010年1月至2012年1月底门诊及住院的腹泻患儿的粪便标本972例,采用胶体金免疫层析法快速检测A组RV抗原.结果 在972例中轮状病毒阳性者为370例,阳性检出率38.1％;男女比例为2.14∶1.2岁以下患儿占轮状病毒腹泻发病率的91.4％.该病高发病率主要集中在较寒冷的季节,即每年的10月至次年的3月,而且从11月到12月为高峰期,但全年各月均有发生,春夏季节的发病率在腹泻患儿中也占有相当的比例(11.1％至41.7％不等).结论 轮状病毒是北京地区婴幼儿感染性腹泻的主要病原体.由其引起的腹泻发病率在＜ 24月龄组的腹泻患儿中所占的比例最大;且以秋冬季节为高发期.因此,即便在春夏季节也应加强对该病的监测与防治,以期在进入年底高发期时能降低其发病率,并为该病进一步的流行病学调查收集和提供更多的动态性资料.     

Distribution and sequence variations of selected virulence genes among group A streptococcal isolates from western Norway

In order to compare the distribution of selected virulence genes among group A streptococci recovered from invasive disease and superficial infections, 42 isolates were screened for mga, speB, speA, ssa and ska, by PCR. The isolates were predominantly of the sequence types emm1, emm3 and emm6, but also included a few of the types emm22, emm28, emm75 and emm78. The phage-mediated speA seemed to be prevalent in emm types 1 and 3, and its distribution was not related to disease severity. The other genes were present in all isolates. The mga, speB and speA were further studied by sequence analysis. Although allotypic associations with invasiveness were not found, allelic specificity to the emm sequence type was observed. In addition, the mga sequences indicated two lineages, related to opacity factor production. A possible recombination between these two main divergent mga genes was observed in isolates of the types emm22 and emm75. A logical nomenclature of the alleles of mga and speB is suggested.     

High rates of antibiotic resistance among normal fecal flora Escherichia coli isolates in children from Greece

Objective: To study the distribution of antibiotic resistant Escherichia coli in the fecal flora of healthy children in Greece.
Methods: Rectal swabs were collected from 181 children, not suffering from infections and not undergoing antibiotic treatment, aged 6 months to 6 years, outpatients of a pediatric hospital, and plated on McConkey agar with ampicillin or trimethoprim. Isolated resistant colonies were identified to the species level and E. coli strains were studied further by molecular methods.
Results: Forty-four per cent of the children carried resistant E. coli , and in 20% resistance was transferable. Forty-seven per cent of the children with no history of antibiotic consumption during the last year were found to carry resistant strains in their feces, and transferable R plasmids were present in 23% of them. Forty per cent of the strains and 30% of the transconjugants were multiresistant. Although plasmids of various molecular weights and restriction endonuclease digest patterns were identified, six 60-MDa and four 80-MDa plasmids, originating from epidemiologically unrelated children, were found to be similar.
Conclusion: Normal flora E. coli in Greece seems to constitute an important reservoir of resistance genes. Eradication of resistance from a population that comes into frequent contact with antibiotics seems to be difficult.     

Distributions of antibody titers to Mycoplasma pneumoniae in Korean children in 2000-2003

The aim of study was to describe Mycoplasma pneumoniae epidemics in a hospital-based population. Special attention was paid to the relationship between antibody titer to M. pneumoniae and sex, age, and atopy. During the eight 6-month periods between January 2000 and December 2003, serum samples were obtained from 1,319 Korean children who presented with respiratory symptoms, and were examined for antibodies to M. pneumoniae using the indirect particle agglutination test. Geometric mean antibody titers peaked in the second half of 2000 and then decreased gradually, a second peak occurred in the second half of 2003. Likewise, the frequency of high antibody titers (> or =1:640) also peaked during these two periods. Antibody titers in children aged 0-3 yr were lower than in older children during both peak periods and for 2 yr after the first peak. Sex and atopy had no effect on antibody titers. During the years 2000-2003, geometric mean antibody titers and the frequencies of high antibody titers varied with time. These changes suggest a cyclic pattern of M. pneumoniae infection, with two epidemic peaks separated by 3 yr.