Serotype distribution and antimicrobial resistance patterns of invasive pneumococcal disease isolates from children in mainland China-a systematic review

Global distribution and characteristics of pneumococcal serotypes in adults

The introduction of pneumococcal conjugate vaccines (PCVs) into pediatric national immunization programs (NIP) has significantly reduced invasive pneumococcal diseases and pneumococcal pneumonia caused by PCV serotypes in adults due to herd immunity. However, diseases caused by PCV13 serotypes persist, mainly serotype 3, known for its severity. With the reduction in PCV13 serotypes, diseases caused by non-PCV13 serotypes increased. Residual and emerging serotypes vary regionally; serotype 8 in Europe and South Africa, and serotype 4 in the US and Canada. PCV20 and PCV21 were recently developed, which can prevent residual and emerging pneumococcal diseases where herd immunity is well-established. In countries that have not introduced PCV into pediatric NIP, the pneumococcal disease burden due to PCV serotypes is still marked. Given that serotype distribution varies by region and evolves over time, this review aimed to discuss serotype distribution and disease severity in adults across countries to support future pneumococcal vaccine strategies.

Immunogenicity and Safety of an Inactivated Quadrivalent Influenza Vaccine Administered Concomitantly with a 23-Valent Pneumococcal Polysaccharide Vaccine in Adults Aged 60 Years and Older

The inactivated quadrivalent influenza vaccine (IIV4) and the 23-valent pneumococcal polysaccharide vaccine (PPSV23) have been administered for years and could be administered concomitantly if necessary. However, the immunogenicity and safety of the concomitant administration of these two vaccines have not been well documented, especially in the Chinese population. In this study, 480 participants aged 60 years and older were randomly assigned to the concomitant administration group (C group) or the separate administration group (S group) to receive IIV4 and PPSV23 either concomitantly or separately. Blood samples were collected before and 28 days after each vaccination. The antibodies against four influenza virus strains and twenty-three pneumococcus serotypes were tested. The results showed that the geometric mean titer (GMT) ratios (C group to S group) for the four influenza strains ranged from 0.72 to 0.95, with the lower limits of the 95% confidence intervals (CIs) ranging from 0.51 to 0.75, and the geometric mean concentration (GMC) ratios for the 23 pneumococcal serotypes ranged from 0.80 to 1.00, with the lower limits of 95% CIs ranging from 0.67 to 0.86. All values met the predefined criteria for non-inferiority. The incidence of adverse events was 0.63% in the C group and 1.56% in the S group. No serious adverse events were observed. In conclusion, the immunogenicity of the concomitant administration of IIV4 and PPSV23 was non-inferior to that of the separate administration, and the safety profile was favorable in adults aged 60 years and older in China.

Exploring the pharmacokinetics of second-generation cephalosporin, cefaclor: a systematic review in healthy and diseased populations

Cefaclor is a bactericidal antibiotic recommended for treating diverse types of infections. This review aims to comprehensively assess the pharmacokinetic (PK) data on cefaclor in humans.Google Scholar, PubMed, Cochrane Library, and EBSCO databases were systematically performed to identify all the relevant studies containing at least one reported PK parameter of cefaclor.Cefaclor shows the linear PK profile as the area under the plasma concentration-time curve from 0 to t (AUC0-t) and maximum plasma concentration (Cmax) increase in a dose-dependent manner. The AUC0-t of cefaclor in the rice diet was found to be higher than that of bread food, i.e. 19.9 ± 2.6 ug/ml.hr vs 15.4 ± 4 ug/ml.hr. The AUC in paediatrics during the fed state was significantly higher compared to that in adults. Patients with renal impairments showed a Cmax 2.2 times higher than that of normal subjects. A significant increase in Cmax was depicted among individuals following a vegetarian diet in comparison with the non-vegetarian diet. Moreover, cefaclor exhibits time-dependent killing above the minimum inhibitory concentration (MIC < 2 ug), favouring its use in treating infections caused by specific pathogens.This systematic review summarises all the reported PK parameters of cefaclor in healthy and diseased subjects in the literature. This data can help practitioners in adjusting cefaclor doses among different diseases and populations to avoid drug interactions and adverse effects.

Molecular characteristics and antimicrobial resistance of invasive pneumococcal isolates from children in the post-13-valent pneumococcal conjugate vaccine era in Shenzhen, China

OBJECTIVES

This study aimed to evaluate the molecular epidemiology and antimicrobial resistance of invasive pneumococcal isolates from children in Shenzhen, China, in the early stage of the pneumococcal 13-valent conjugated vaccine (PCV-13) era from 2018 to 2020.

METHODS

Invasive pneumococcal strains were isolated from hospitalized children with invasive pneumococcal diseases (IPDs) from January 2018 to December 2020. The serotype identification, multilocus sequence typing (MLST), and antibiotic susceptibility tests were performed on all culture-confirmed strains.

RESULTS

Sixty-four invasive strains were isolated mainly from blood (70.3%). Prevalent serotypes were 23F (28.1%), 14 (18.8%), 19F (15.6%), 6A/B (14.1%), and 19A (12.5%), with a serotype coverage rate of 96.9% for PCV13. The most common sequence types (STs) were ST876 (17.1%), ST271 (10.9%), and ST320 (7.8%). Half of the strains were grouped in clonal complexes (CCs): CC271 (21.9%), CC876 (20.3%), and CC90 (14.1%). Meningitis isolates showed a higher resistance rate (90.9% and 45.5%) to penicillin and ceftriaxone than the rate (3.8% and 9.4%) of non-meningitis isolates. The resistance rates for penicillin (oral), cefuroxime, and erythromycin were 53.13%, 73.4%, and 96.9%, respectively. The dual ermB and mefA genotype was found in 81.3% of erythromycin-resistant strains. The elevated minimum inhibitory concentration (MIC) of β-lactam antibiotics and dual-genotype macrolide resistance were related mainly to three major serotype-CC combinations: 19F-CC271, 19A-CC271, and 14-CC876.

CONCLUSION

Invasive pneumococcus with elevated MICs of β-lactams and increased dual ermB and mefA genotype macrolide resistance were alarming. Expanded PCV13 vaccination is expected to reduce the burden of paediatric IPD and to combat antibiotic-resistant pneumococcus in Shenzhen.

Serotype, antibiotic susceptibility and whole-genome characterization of Streptococcus pneumoniae in all age groups living in Southwest China during 2018-2022

Background

Streptococcus pneumoniae is a common pathogen that colonizes the human upper respiratory tract, causing high morbidity and mortality worldwide. This study aimed to investigate the prevalence status of S. pneumoniae isolated from patients of all ages in Southwest China, including serotype, antibiotic susceptibility and other molecular characteristics, to provide a basis for clinical antibiotic usage and vaccine development.

Methods

This study was conducted from January 2018 to March 2022 at West China Hospital, West China Second University Hospital, First People's Hospital of Longquanyi District (West China Longquan Hospital), Meishan Women and Children's Hospital (Alliance Hospital of West China Second University Hospital) and Chengdu Jinjiang Hospital for Women and Children Health. Demographic and clinical characteristics of 263 pneumococcal disease (PD) all-age patients were collected and analyzed. The serotypes, sequence types (STs), and antibiotic resistance of the strains were determined by next-generation sequencing, sequence analysis and the microdilution broth method.

Results

The most common pneumococcal serotypes were 19F (17.87%), 19A (11.41%), 3 (8.75%), 23F (6.46%) and 6A (5.70%). Coverage rates for PCV10, PCV13, PCV15, PCV20 and PCV24 were 36.12, 61.98, 61.98, 63.12 and 64.26%, respectively. Prevalent STs were ST271 (12.55%), ST320 (11.79%), ST90 (4.18%), ST876 (4.18%) and ST11972 (3.42%). Penicillin-resistant S. pneumoniae (PRSP) accounted for 82.35 and 1.22% of meningitis and nonmeningitis PD cases, respectively. Resistance genes msrD (32.7%), mefA (32.7%), ermB (95.8%), tetM (97.3%) and catTC (7.6%) were found among 263 isolates. Most isolates showed high resistance to erythromycin (96.96%) and tetracycline (79.85%), with more than half being resistant to SXT (58.94%). A few isolates were resistant to AMX (9.89%), CTX (11.03%), MEN (9.13%), OFX (1.14%), LVX (1.14%) and MXF (0.38%). All isolates were susceptible to vancomycin and linezolid.

Conclusion

Our study provides reliable information, including the prevalence, molecular characterization and antimicrobial resistance of S. pneumoniae isolates causing pneumococcal diseases in Southwest China. The findings contribute to informed and clinical policy decisions for prevention and treatment.

Monitoring Over a Decade in the Serotype Prevalence of Streptococcus pneumoniae in Iran: A Systematic Review and Meta-analysis

BACKGROUND

There is no comprehensive information about the circulating serotypes of Streptococcus pneumoniae in Iran in recent years. This study aimed to summarize information about the changes over a decade in the serotype prevalence of S. pneumoniae in Iran.

METHODS

We performed a comprehensive search in PubMed/Medline, Web of Science, Science Direct, and the Iranian Database, such as Magiran and SID, from January 2011 to February 2023. The systematic process, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), was carried out by two researchers who were both independent and calibrated. Statistical analyses were carried out using Comprehensive Meta-Analysis software. Identifying and measuring heterogeneity were done using I2 and the chi-square test. Finally, Begg's rank correlation test was used in combination with a funnel plot to evaluate any possible publication bias.

RESULTS

The search returned 16 relevant results, with a total of 1575 isolates. Of those studies, eight studies reported the distribution of S. pneumoniae serotypes among patients, three studies among healthy individuals, and five studies among both groups. As the meta-analysis revealed, the most common serotypes were 23F (n = 299, 14.1% [95% CI: 9.7-19.9]; I2 = 84.3%; P<0.001 for heterogeneity), 19F (n = 221, 13.4% [95% CI: 9.9-17.9; I2 = 76.7%; P<0.001 for heterogeneity]), and 19A (n = 102, 8.7% [95% CI: 6.5-11.7; I2 = 54.3%; P<0.001 for heterogeneity]). Moreover, Begg's test (P = 0.160, 0.173, and 0.176 for 23F, 19F, and 19A, respectively) showed no evidence of publication bias.

CONCLUSION

Based on our pooled results, the majority of the serotypes of pneumococci in the Iranian population were 23F, 19F, and 19A, respectively, over the last decade. The findings can be valuable in selecting effective pneumococcal vaccine candidates and targeted antibiotics in Iranian patients.

The dynamic change of serotype distribution and antimicrobial resistance of pneumococcal isolates since PCV13 administration and COVID-19 control in Urumqi, China

Objective

This study aims to analyze the serotype distribution and drug resistance of Streptococcus pneumoniae isolated from children aged 8 days to 7 years in Urumqi, China, between 2014 to 2021, during which PCV13 was introduced in the private sector's immunization program and COVID-19 control was administrated in the last 2 years.

Methods

Serotypes of S. pneumoniae isolates were determined by Quellung reaction, and their susceptibility against 14 antimicrobials were tested. According to the start year of PCV13 administration (2017) and COVID-19 control (2020), the study period was divided into three stages: 2014-2015, 2018-2019, and 2020-2021.

Results

A total of 317 isolates were involved in this study. The most common serotypes were type 19F (34.4%), followed by 19A (15.8%), 23F (11.7%), 6B (11.4%), and 6A(5.0%). The coverage rate of both PCV13 and PCV15 was 83.0%. The coverage of PCV20 was a little higher at 85.2%. The resistance rate against penicillin was 28.6% according to the breakpoints of oral penicillin, which would reach up to 91.8% based on the breakpoints of parenteral penicillin for meningitis. The resistance rates to erythromycin, clindamycin, tetracycline, and sulfamethoxazole-trimethoprim were 95.9%, 90.2%, 88.9%, and 78.8%, respectively. The PCV13 isolate was more resistant to penicillin than the non-PCV13 ones. There was not any significant change found in the serotype distribution since the PCV13 introduction and the COVID-19 control. The resistance rate against oral penicillin slightly elevated to 34.5% in 2018-2019 from 30.7% in 2014-2015 and then decreased significantly to 18.1% in 2020-2021 (χ ² = 7.716, P < 0.05), while the resistance rate to ceftriaxone (non-meningitis) continuously declined from 16.0% in 2014-2015 to 1.4% in 2018-2019 and 0% in 2020-2021 (Fisher = 24.463, P < 0.01).

Conclusion

The common serotypes of S. pneumoniae isolated from children in Urumqi were types 19F, 19A, 23F, 6B, and 6A, which we found to have no marked change since the PCV13 introduction and the COVID-19 control However, the resistance rate to oral penicillin and ceftriaxone significantly declined in the COVID-19 control stage.

Lung penetration and pneumococcal target binding of antibiotics in lower respiratory tract infection

OBJECTIVES

To achieve the therapeutic effects, antibiotics must penetrate rapidly into infection sites and bind to targets. This study reviewed updated knowledge on the ability of antibiotics to penetrate into the lung, their physicochemical properties influencing the pulmonary penetration and their ability to bind to targets on pneumococci.

METHODS

A search strategy was developed using PubMED, Web of Science, and ChEMBL. Data on serum protein binding, drug concentration, target binding ability, drug transporters, lung penetration, physicochemical properties of antibiotics in low respiratory tract infection (LRTI) were collected.

RESULTS

It was seen that infection site-to-serum concentration ratios of most antibiotics are >1 at different time points except for ceftriaxone, clindamycin and vancomycin. Most agents have proper physicochemical properties that facilitate antibiotic penetration. In antimicrobial-resistant Streptococcus pneumoniae, the binding affinity of antibiotics to targets mostly decreases compared to that in susceptible strains. The data on binding affinity of linezolid, clindamycin and vancomycin were insufficient. The higher drug concentration at the infection sites compared to that in the blood can be associated with inflammation conditions. Little evidence showed the effect of drug transporters on the clinical efficacy of antibiotics against LRTI.

CONCLUSIONS

Data on antibiotic penetration into the lung in LRTI patients and binding affinity of antibiotics for pneumococcal targets are still limited. Further studies are required to clarify the associations of the lung penetration and target binding ability of antibitotics with therapeutic efficacy to help propose the right antibiotics for LRTI.

Systematic review of the clinical outcomes of pneumonia with a penicillin-group resistant pneumococcus in respiratory and blood culture specimens in children in low- and middle-income countries

Background

Streptococcus pneumoniae is one of the most common bacteria causing pneumonia and the World Health Organization (WHO) recommends first-line treatment of pneumonia with penicillins. Due to increases in the frequency of penicillin resistance, this systematic review aimed to determine the clinical outcomes of children with pneumonia in low- and middle-income countries (LMICs), with penicillin-group resistant pneumococci in respiratory and/or blood cultures specimens.

Methods

English-language articles from January 2000 to November 2020 were identified by searching four databases. Systematic reviews and epidemiological studies from LMICs that included children aged one month to 9 years and reported outcomes of pneumonia with a penicillin-resistant pneumococcus in respiratory and blood culture specimens with or without comparison groups were included. Risk of bias was assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. A narrative synthesis of findings based on the results of included studies was performed.

Results

We included 7 articles involving 2864 children. One strong- and four medium-quality studies showed no difference in clinical outcomes (duration of symptoms, length of hospital stay and mortality) between those children with penicillin non-susceptible compared to susceptible pneumococci. Two weak quality studies suggested better outcomes in the penicillin-susceptible group.

Conclusions

Current evidence suggests no difference in clinical outcomes of child pneumonia due to a penicillin-resistant S. pneumoniae and as such, there is no evidence to support a change in current WHO antibiotic guidelines.

Clinical characteristics, antimicrobial resistance, and risk factors for mortality in paediatric invasive pneumococcal disease in Beijing, 2012-2017

Background

To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing.

Methods

Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed.

Results

Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/μL were independent risk factors for mortality.

Conclusion

Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.

Chinese expert consensus on immunoprophylaxis of common respiratory pathogens in children (2021 edition)

Respiratory tract infections are infectious diseases involving the respiratory tract (such as the sinuses, throat, airways or lungs), which are the common respiratory disorders in children. With the development of society and the improvement of economic conditions, great progress has been made in China in the prevention of common respiratory pathogens in children. As a result, the incidence and mortality of respiratory tract infections in children have dropped sharply in the past decades. However, there is still a certain gap compared with the international leading levels, which can be partly attribute to insufficient public awareness of vaccination, uneven vaccination services of vaccinators, and so on. On the basis of comprehensive analysis of the clinical evidence of immunoprophylaxis of common respiratory pathogens among children in China and abroad, combined with the clinical situation and the experience of experts, the consensus focuses on the characteristics of transmission, clinical manifestations and immunoprophylaxis of common respiratory pathogens in children, so as to provide reference for clinical practice. This consensus document applies to all Centers for Disease Control and Prevention (CDC) staff levels engaged in the prevention and control of related pathogens, vaccinators at vaccination sites, and medical staff in pediatric, respiratory, and infectious diseases departments at all levels in medical institutions.

Effect of pneumococcal conjugate vaccine availability on Streptococcus pneumoniae infections and genetic recombination in Zhejiang, China from 2009 to 2019

Pneumococcal pneumonia is one of the main reasons for child death worldwide. Pneumococcal conjugate vaccines (PCVs) are considered the most effective strategy for pneumococcal disease (PD) prevention, but how a pause in PCV vaccination affects the prevalence of PD or the genetic evolution of Streptococcus pneumoniae genetic evolution is unknown. Based on the unique PCV introduction timeline (vaccine unavailable during April 2015-April 2017) in China, we aimed to evaluate the effect of interrupted PCV availability on PD and pneumococcal genome variation. Pneumococcal isolates (n = 386) were collected retrospectively from eight sites in Zhejiang, China from 2009 to 2019 in which 184 pathogenic (isolates from sterile and infection sites) strains were identified. An interrupted time series analysis was conducted to estimate changes in PD and the recombination frequency of whole genome-sequenced strains was estimated via SNP calling. We found that both PD and pneumococcal genome variation were affected by interrupted PCV availability. The proportion (∼70%) of vaccine-type pneumococcal LRTI (VT-LRTI) in all LRTI cases decreased to ∼30% in the later PCV7 period and rebounded to ∼70% in children once PCV7 became unavailable in April 2015 (p = 0.0007). The major clone CC271 strains showed slowed (p = 0.0293) recombination frequency (decreased from 2.82 ± 1.16–0.72 ± 0.21) upon PCV removal. Our study illustrated for the first time that VT-LRTI fluctuated upon interrupted vaccine availability in China and causing a decreased of recombination frequency of vaccine types. Promoting a nationwide continuous vaccination programme and strengthening S. pneumoniae molecular epidemiology surveillance are essential for PD prevention.