绍兴地区肺炎链球菌的血清型和耐药性

目的:调查绍兴地区流行肺炎链球菌的血清型和耐药性,对不同来源的菌株进行比较,计算PCV7的覆盖率,为临床用药提供指导。方法:收集105株不同样本来源的肺炎链球菌,使用Pneumotest-latex鉴定血清型,统计耐药性,并研究两者之间关系。结果:105株肺炎链球菌,青霉素不敏感仅1株咽拭子分离菌,红霉素、克林霉素耐药率为99.3%,未检到万古霉素、左氧氟沙星耐药株,复方SMZ、四环素、利福平、氯霉素的耐药率分别为77.9%、86.2%、5.1%、10.6%。主要检出的血清组/型为19和23,占所有菌株的47.6%(49/103),PCV疫苗覆盖率为62.1%。结论:不同样本来源的肺炎链球菌的流行血清型和耐药性差异有统计学意义,眼部分离肺炎链球菌较其他部位分离株耐药程度低,PCV7覆盖率低,需长期监测。     

Streptococcus pneumoniae: prevalence in nasopharyngeal carriers of more than 50-years-old,in a Mexican rural community

Introduction

Streptococcus pneumoniae (Sp) is the main cause of community-acquired pneumonia in the elderly, hence the importance to establish the prevalence of nasopharyngeal colonization by different Sp serotypes in adults.

Changes in the incidence of Streptococcus pneumoniae bacteremia and its serotypes over 10 years in one hospital in South Korea

Here, we examined the distribution of pneumococcal serotypes and the antibiotic susceptibility of Streptococcus pneumoniae in clinical blood isolates. The serotypes of 91 S. pneumoniae blood isolates, collected from January 2003 to March 2014, were identified by multiplex PCR and sequencing. The most common serotypes were 19F, 19A, 3, 4, and 14, accounting for 53.8% of the total. The serotype coverage rates of pneumococcal conjugated vaccine (PCV) 7, PCV10, and PCV13 were different during three test periods: 38.7%, 70.9%, and 93.5% in period I (2003–2005), 46.8%, 50.0%, and 75.0% in period II (2006–2008), and 28.5%, 32.1%, and 64.2% in period III (2009–2014), respectively. By contrast, the number of non-PCV13 serotypes increased from 6.4% in period I to 25% and 35.7% in periods II and III, respectively. The susceptibility of non-PCV13 serotypes to antimicrobial agents (penicillin, erythromycin, cefotaxime, and meropenem) was higher than that of PCV serotypes. In particular, non-PCV13 serotypes showed 100% and 95% susceptibility to penicillin and cefotaxime, respectively. Serotypes 19A and 19F showed high prevalence (79.1%) among 24 multi-drug resistant (MDR) isolates. Notably, all serotype 19A isolates were MDR. From January 2003 to March 2014, the proportion of non-PCV13 serotype pneumococci in blood isolates increased whereas the coverage rate of PCV13 decreased. Effective pneumococcal vaccines are required to protect against MDR serotype 19A isolates and the increasing number of non-PCV13 serotypes.     

不同血清型乙型肝炎患者血清和唾液中HBV-DNA含量相关性研究

目的探讨不同血清型乙型肝炎患者血清和唾液中HBV-DNA的差异以及相关性.方法选取60例乙型肝炎患者,分别采用实时荧光定量PCR法同时检测血清与唾液HBV-DNA,用ELISA检测血清HBV标志物,动力学方法检测血清ALT值,并分析其相互关系.结果60例乙型肝炎患者血清与唾液HBV-DNA阳性率分别为93.3％和63.3％(x2=15.91,P＜0.01);HBeAg阳性患者33例,HBeAg阴性患者26例,其血清HBV-DNA阳性率分别为97.15％和88.5％(x2=0.64,P＞0.05);ALT值的四分位间距分别为69.0(45.0～220.5)和38.5 (24.0～103.5)(t=1.36,P=0.180);血清HBV-DNA对数值的四分位间距分别为7.14(6.01～7.62)和5.09(2.30～6.83)(t=3.70,P＜0.05);唾液HBV-DNA对数值的四分位间距分别为4.63(1.19～5.29)和0.00(0.00～4.6)(t=3.25,P＜0.05).对60例乙型肝炎患者血清与唾液HBV-DNA病毒含量的对数值进行分析,发现两者呈显著的正相关(r=0.83,P＜0.05),回归方程为y=0.88x+2.82.结论HBeAg阳性的患者与HBeAg阴性患者相比较,虽然血清中病毒阳性率以及ALT值无差异,但病毒含量有差异.乙型肝炎患者血清与唾液中的病毒含量呈正相关,血清中病毒含量高于唾液,提示血清的传染性比唾液强.     

Escherichia albertii, a newly emerging enteric pathogen with poorly defined properties

Escherichia albertii is a newly emerging enteric pathogen that has been associated with sporadic infections among humans and birds. Selected coliform isolates were screened for allelic variation in 2 housekeeping genes (lysP and mdh) specific for E. albertii. The 48 strains that were identified as E. albertii were tested for 15 virulence markers and biochemical and serogical properties. All E. albertii strains were non-motile, fermented D-glucose (with gas), D-mannitol, and D-mannose, but failed to ferment lactose and other sugars. Variable positive reactions were noted for other tests. Most strains were rough or failed to agglutinate with Shigella boydii 13 antisera and E. coli antisera with few exceptions. All strains were positive for the eaeA gene, and variable numbers were positive for the cdtB, phoE, ehxA, and stx2f genes. Results illustrate the variability extent within this lineage and highlight the importance of accurately distinguishing it within the genus Escherichia and including information within commercial databases to improve their identification.     

Long-term mortality after IPD and bacteremic versus non-bacteremic pneumococcal pneumonia

BackgroundShort-term mortality after invasive pneumococcal disease (IPD) and pneumococcal pneumonia is high but data on long-term mortality (including the comparison between bacteremic and non-invasive/non-bacteremic pneumococcal pneumonia) within the first years after diagnosis are scarce.MethodsAdult patients with ‘non-pneumonia’ IPD and ‘invasive pneumonia’ (from 2004 to 2012) and with ‘bacteremic’ vs ‘non-invasive/non-bacteremic (NI/NB)’ pneumococcal pneumonia (from 2008 to 2012) diagnosed by negative blood culture but a positive urinary antigen test (UAT) were identified in a Dutch hospital. Mortality of patients up to 10 years after diagnosis was compared with age- and sex-matched life-expectancy data of the general population. Multivariable Cox regression analysis was used to study predictors for mortality in invasive pneumonia patients and to adjust for confounders comparing mortality between bacteremic and NI/NB/UAT-positive pneumonia patients.ResultsOf 228 invasive pneumonia patients 17% died within 30 days and in 30-day survivors cumulative long-term mortality at 1 and 5 years were 16% and 39% as compared with 3% and 15% in age- and sex-matched persons. High mortality was largely dependent on pre-existent comorbidities. In invasive pneumonia patients who survived the first 30 days, age, male gender, chronic cardiovascular disease, malignancy and PCV7 serotype disease were independent predictors for higher long-term mortality. For bacteremic pneumonia patients (n = 128) 30-day mortality was 16% and almost similar to 14% in NI/NB/UAT-positive pneumococcal pneumonia patients (n = 170). In 30-day survivors of bacteremic pneumonia (n = 108, median age 66 years), cumulative mortality at 1 and 3 years were 13% and 29% as compared with 18% and 40% in NI/NB/UAT-positive pneumococcal pneumonia patients (n = 146, median age 67 years) without a significant difference in mortality.ConclusionsApproximately 40% of all patients, who survived the first 30 days after presentation with non-pneumonia IPD and pneumococcal pneumonia died within the following 5 years. High long-term mortality was largely dependent on pre-existent comorbidity.     

EnteropathognicEscherichia coli diarrhea in hospitalized children at Delhi

Prevalence of enteropathogenicE. coli (EPEC) in 4178 cases of acute diarrhea in hospitalised children of <2 years old admitted during 1980–1985 was studied.E. coli in pure culture was obtained from 15·5% of the stool samples. Of the isolates 58·8% were typable, however, only 43·2% belonged to known EPEC serotypes. The commonest serotype, was 020 (21·1%), followed by 018 (20·7%), 026 (8·8%), 0119 (8·4%), 0125 (7·7%), 086 (6·1%) and others. Majority of the serotypes were obtained from males and in the age group >6–12 months.     

Possibility of application of new pneumococcal conjugate vaccines in children in Slovenia

The emergence of pneumococcal strains resistant to penicillin caused a lot of problems in the therapy of invasive diseases, and added new dimensions to the role of immunisation. In addition to the currently available 23-valent pneumococcal polysaccharide vaccine (PPV) and a new 7-valent conjugate vaccine (PCV) (Prevnar, Wyeth Lederle), two new conjugate vaccines—a 9- and a 11-valent—are being developed. So far, the choice of most appropriate vaccines has depended on the established prevalence of serotypes causing invasive diseases and their antibiotic resistance in the Slovene children population. Between 1993 and 2001, 263 invasive pneumococcal strains isolated from children with invasive diseases were typed. During the period 1998–2001, the same 161 invasive strains were tested for their antibiotic sensitivity. Streptococcus pneumoniae was identified as the major cause of invasive bacterial diseases in the Slovene children population, especially in children under 4 years of age. Distribution by age groups showed the highest incidence in children aged 0–1 years. The predominant serotypes in all age groups were serotypes 14, 1, 19F, 23F, 6B, 18C and 6A. The distribution of penicillin-intermediate and penicillin-resistant strains showed the predominance of serotypes 23F, 14 and 19F. As concerns infection with S. pneumoniae serotypes, we have proved that children aged less than 5 years are more likely to be infected with penicillin-nonsusceptible or intermediate susceptible strains than older children. The 7-valent conjugate vaccine covers 74% of invasive strains in toddlers, but is less effective in older children.

We can conclude that the 9-valent vaccine formulation is optimal for our country, but further cost-effectiveness analysis must be done for recommendation of wide use.

At that moment it is reasonable to use the 7-valent conjugate vaccine for children with chronic cardiovascular, pulmonary, urinary and liver diseases, with asplenia, neoplasmia, diabetes, meningomyelocoele, before or after bone marrow transplantation and in cases of immunodeficiency.     

Phenotypic and genotypic characteristics of non-invasive S. pneumoniae isolates recovered from PCV10-vaccinated children in Bulgaria

PurposeThe non-invasive pneumococcal disease (NIPD) is a common infection during childhood. We aimed to define the clonal spread of pediatric non-invasive isolates recovered during the PCV10-period in Bulgaria concerning the serotype and antimicrobial susceptibility.Materials and methodsSerogrouping/serotyping were performed using latex agglutination and capsular swelling reaction. Serogroup 6 strains were subjected to serotype-specific PCR's. The antibiotic susceptibilities were assessed by broth microdilution. MLST was performed to define the clonal composition.ResultsWe analyzed 154 pediatrics non-invasive S. pneumoniae isolates. The PCV10-vaccinated children were 94.1%. We disclosed 88% non-vaccine serotypes (NVTs) and 12% PCV10 - serotypes. All common serotypes among PCV10-vaccinated children (n ?= ?145) were non-vaccine types (NVTs): 19A (13.8%), 6C (11.7%), 3 (9.6%), 15A (8.3%) and 23A (5.5%). Antimicrobial non-susceptibility showed highest levels in erythromycin (50.0%), oral penicillin (49.4%), clindamycin (45.4%), trimethoprim-sulfamethoxazole (43.5%), tetracycline (42.2%), and ceftriaxone (14.3%). The multidrug-resistant strains (MDR) were 51.3%. MDR-serotypes were 6C (20.2%), 19A (17.7%), 15A (11.4%), 19F (10.1%), and 23A (8.9%). MLST presented 17 clonal complexes (CCs) with prevalence of CC320, CC386, CC505, CC8029 and CC2613 clustered 83% MDR isolates.ConclusionsAll emergent pediatric non-invasive serotypes in our geographic area during the studied PCV10-period were NVTs (19A, 6C, 3, 15A, and 23A). The fifth widespread CCs: CC320, CC386, CC505, CC8029 and CC2613 clustered 83% MDR isolates. Future surveillance of vaccine-induced changes in the clonality and the antimicrobial resistance of the pneumococcal population is needed.     

The changing phenotypes and genotypes of invasive pneumococcal isolates from children in Shenzhen during 2013–2017

BackgroundThe phenotypes and genotypes of Streptococcus pneumoniae isolated from invasive pneumococcal diseases (IPDs) were changing all the time. To monitor these changes of phenotypes and genotypes of S. pneumoniae isolates from children, we examined antibiotic susceptibility, serotype distribution and sequence types (STs) of S. pneumoniae, which were isolated before the 13-valent pneumococcal conjugate vaccine (PCV13) introduced into China.MethodsStrains were isolated from children less than 14 years old between January 2013 and May 2017 from Shenzhen Children’s Hospital. Serotypes, antibiotic resistance, and genotypes of these isolates were determined using capsular swelling, E-test, and multi-locus sequence typing, respectively.ResultsA total of 94 S. pneumoniae strains were isolated, which belonged to 15 serotypes. The five most prevalent serotypes were 19F (25.5%), 19A (19%), 14 (17%), 23F (7.5%), and 6B (9.6%). We found 42 STs for these isolates. The most abundant STs were ST271 (24.4%), ST876 (17%), and ST320 (10.6%), mainly related to 19F, 14, and 19A, respectively. The potential coverage of PCV13 was 87.2%. Among non-meningitis isolates, the resistance rates to penicillin and ceftriaxone were 0% and 2%. However, the meningitis isolates showed high resistance to penicillin (80%) and ceftriaxone (20%). Most of these isolates (95.7%) were resistant to erythromycin, and 66 (70.2%) strains carried the ermB gene and 24 (25.5%) strains carried both the ermB and mefA/E genes. Serotype 19A showed the highest mean minimum inhibitory concentration (MIC) for penicillin (MIC = 1.486) than the other serotypes, but no significant difference in penicillin MIC among the three main STs (ST271, ST320, and ST876).ConclusionsThe phenotypes and genotypes of invasive pneumococcal isolates from Shenzhen Children’s Hospital have changed with the passage of time. Compared with PCV7, PCV13 can more effectively protect Chinese children from IPDs. To some extent, these changes are possibly related to the usage of antibiotics and vaccines.