Serotype distribution and antibiotic resistance of Streptococcus pneumoniae isolates from 17 Chinese cities from 2011 to 2016

Serotype distribution, antibiotic resistance, multilocus sequence typing, and virulence factors of invasive and non-invasive Streptococcus pneumoniae in Northeast China from 2000 to 2021

Streptococcus pneumoniae infection is a major public health concern with high morbidity and mortality rates. This study aimed to evaluate the serotype distribution, antimicrobial resistance changes, clonal composition, and virulence factors of S. pneumoniae isolates causing pneumococcal disease in northeast China from 2000 to 2021. A total of 1,454 S. pneumoniae isolates were included, with 568 invasive strains and 886 non-invasive strains. The patients from whom the S. pneumoniae were isolated ranged in age from 26 days to 95 years, with those ≤ 5 years old comprising the largest group (67.19%). 19 F, 19 A, 23 F, 14, and 6B were the most common serotypes, of which 19 A and 19 F were the main serotypes of invasive and non-invasive S. pneumoniae, respectively. CC271 was the most common multilocus sequence type. Serotype 14 had the lowest expression of cbpA, rrgA, and psrP genes, but expression levels of 19 A and 19 F genes were similar. All isolates were sensitive to ertapenem, moxifloxacin, linezolid, and vancomycin but highly resistant to macrolides, tetracyclines, and cotrimoxazole. Simultaneous resistance to erythromycin, clindamycin, tetracyclines, and trimethoprim/sulfamethoxazole was common pattern among multidrug-resistant isolates. Non-invasive S. pneumoniae had higher resistance to β-lactam antibiotics than invasive strains. 19 A and 19 F were the main strains of penicillin-resistant S. pneumoniae. The resistance rate of β-lactam antibiotics decreased from 2017 to 2021 compared to previous periods. Including PCV13 in the national immunization program can reduce the morbidity and mortality rates of pneumococcal disease effectively.

Investigating the Distribution and Antibiotic Resistance of Bacterial Pathogens in Clinical Specimens from a Chinese Maternal and Child Hospital: The Role of Environmental Factors

Objective

To analyze bacterial distribution and antibiotic resistance in clinical specimens from a Chinese hospital for evaluating environmental factors' impact on pathogen prevalence.

Methods

From January 2017 to December 2021, we collected 42,854 clinical specimens from hospitalized children and women. The specimens were cultured on various agar plates and incubated at 35°C for 18-48 h. Their identification was performed using standard biochemical methods and Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), whereas antibiotic susceptibilities were determined using the VITEK 2 system. Concurrent environmental data from Wuhan were analyzed for correlations with pathogen prevalence using multiple linear stepwise regression.

Results

Of the 24,555 bacterial strains isolated, the majority were gram-positive, and sputum was the most common specimen type. Haemophilus influenzae and Escherichia coli were the most prevalent pathogens in sputum and urine samples, respectively. Notably, H. influenzae and Streptococcus pneumoniae affected children under 6 years of age the most. Furthermore, H. influenzae showed high ampicillin resistance but low cefotaxime resistance; S. pneumoniae was sensitive to penicillin G, and E. coli was resistant to ampicillin but sensitive to cefotetan. The prevalence of multidrug-resistant organisms was below national averages. In terms of seasonality, H. influenzae peaked during late winter and early spring, and environmental analysis indicated positive correlations between PM2.5 and PM10, and H. influenzae and S. pneumoniae prevalence. In addition, NO2 levels were positively correlated with increased S. aureus and M. catarrhalis prevalence; E coli prevalence was negatively correlated with ozone levels.

Conclusion

This study provides valuable insights into the distribution and antibiotic resistance patterns of bacterial pathogens in maternal and child healthcare facilities in Wuhan, China. Environmental factors significantly influence the epidemiology of certain bacterial pathogens. Implementing integrated health strategies that combine microbial surveillance with environmental monitoring is needed to effectively manage and prevent bacterial infections.

Bacterial Etiology and Antimicrobial Resistance Pattern of Pediatric Bloodstream Infections in Beijing, 2015-2019

Purpose

Bloodstream infections (BSIs) was an essential cause of morbidity and mortality in children. Empiric broad-spectrum treatment of BSIs may be costly and unable to effectively eliminate the correct pathogenic microbes, resulting in downstream antimicrobial resistance. The purpose was to provide evidence for diagnosis and treatment of bloodstream infections in pediatrics, by revealing the pathogen distribution and antibiotic resistance pattern of BSIs.

Methods

In this 5-year study, a total of 2544 pathogenic bacteria stains, isolated from 2368 patients with BSI, were retrospectively analyzed, to define the species distribution and the antimicrobial resistance pattern in Beijing.

Results

The most frequently isolated pathogenic bacteria were K. pneumoniae (12.1%), S. aureus (11.5%), E. coli (11.2%), and E. faecium (11.2%). Hematological malignancies were the most common disease among patients with underlying conditions. Methicillin resistance was detected in 30.0% of S. aureus and 81.7% of coagulase-negative Staphylococcus (CoNS), respectively. The detection rates of carbapenem-resistant-E. coli (CRECO) and carbapenem-resistant-K. pneumoniae (CRKPN) were 10.8% and 50.8%, respectively. In terms of 122 isolates of S. pneumonia, 5 isolates (4.1%) were penicillin-resistant Streptococcus pneumoniae (PRSP); meanwhile, 50 isolates (41.0%) were penicillin-intermediate Streptococcus pneumoniae (PISP). Among the non-fermentative gram-negative bacilli isolates, 22.8% and 26.9% of the P. aeruginosa, were resistant to imipenem and meropenem. Furthermore, the resistance rates of A. baumannii to imipenem and meropenem both were 54.5%.

Conclusion

In the study, we demonstrated the characteristics of bloodstream infections and antimicrobial susceptibility pattern of pediatrics in Beijing. Gram positive bacteria were the main pathogens of BSIs. CoNS strains presented even higher resistance to multiple antibiotics, including methicillin, than S. aureus. K. pneumoniae and E. coli represent the most common isolated gram-negative bacteria and exhibited high resistance to a variety of antimicrobial agents. Therefore, it was of critical importance to implement appropriate antimicrobial medication according to pathogen distribution and drug susceptibility test.

Severe problem of macrolides resistance to common pathogens in China

With the widespread use of macrolide antibiotics in China, common pathogens causing children's infections, such as Streptococcus pneumoniae, Streptococcus (including Group A streptococcus, Group B streptococcus), Staphylococcus aureus, Bordetella pertussis, and Mycoplasma pneumoniae, have shown varying degrees of drug resistance. In order to provide such problem and related evidence for rational use of antibiotics in clinic, we reviewed the drug resistance of common bacteria to macrolides in children recent 20 years.

Genomic Epidemiology of Streptococcus pneumoniae Isolated in a Tertiary Hospital in Beijing, China, from 2018 to 2022

Streptococcus pneumoniae is one of the most common bacterial pathogens of a wide range of community-acquired infections. It has been more and more recognized that this bacterium could also play a role as a cause of nosocomial infections. In this study, by retrospective analysis of the phenotypic resistance characteristics and genomic characteristics of 52 S. pneumoniae isolates in a hospital in Beijing, China, from 2018 to 2022, we explored the carriage of resistance genes and mutations in penicillin-binding proteins corresponding to the resistances, and identified the population diversity based on the prediction of serotypes and identification of sequence types (STs). The isolates displayed resistances to erythromycin (98%), tetracycline (96%), sulfonamide (72%) and penicillin G (42%). Among the 52 isolates, 41 displayed multiple-drug resistance. In total, 37 STs and 21 serotypes were identified, and the clonal complex 271 serogroup 19 was the most prevalent subtype. Only 24 isolates (46.2%) of 7 serotypes were covered by the 13-valent pneumococcal conjugate vaccination. The isolates showed high carriages of resistance genes, including tet(M) (100%) and erm(B) (98.1%); additionally, 32 isolates (61.5%) had mutations in penicillin-binding proteins. We also observed 11 healthcare-associated infections and 3 cases infected by different subtypes of isolates. We did not find nosocomial transmissions between the patients, and these cases might be associated with the asymptomatic colonization of S. pneumoniae in the human population. Our results called for further active surveillance of these subtypes, as well as the continuous optimization of the treatment protocols.

An Overview of Macrolide Resistance in Streptococci: Prevalence, Mobile Elements and Dynamics

Streptococcal infections are usually treated with beta-lactam antibiotics, but, in case of allergic patients or reduced antibiotic susceptibility, macrolides and fluoroquinolones are the main alternatives. This work focuses on studying macrolide resistance rates, genetic associated determinants and antibiotic consumption data in Spain, Europe and also on a global scale. Macrolide resistance (MR) determinants, such as ribosomal methylases (erm(B), erm(TR), erm(T)) or active antibiotic efflux pumps and ribosomal protectors (mef(A/E)-mrs(D)), are differently distributed worldwide and associated with different clonal lineages and mobile genetic elements. MR rates vary together depending on clonal dynamics and on antibiotic consumption applying selective pressure. Among Streptococcus, higher MR rates are found in the viridans group, Streptococcus pneumoniae and Streptococcus agalactiae, and lower MR rates are described in Streptococcus pyogenes. When considering different geographic areas, higher resistance rates are usually found in East-Asian countries and milder or lower in the US and Europe. Unfortunately, the availability of data varies also between countries; it is scarce in low- and middle- income countries from Africa and South America. Thus, surveillance studies of macrolide resistance rates and the resistance determinants involved should be promoted to complete global knowledge among macrolide resistance dynamics.

What is the global prevalence of depression among men who have sex with men? A systematic review and meta-analysis

BACKGROUND

Depression due to stigma resulting from their sexual identity, isolation, social exclusion, and insufficient access to care and counseling services has become a health problem among men who have sex with men (MSM).

OBJECTIVES

This study aimed to determine the global prevalence of depression among MSM as a systematic review and meta-analysis.

METHODS

This study was a systematic review and meta-analysis performed in five steps of search strategy, screening and selecting articles, data extraction, evaluation of the risk of bias, and meta-analysis. In this study, the determined keywords were searched in the databases of PubMed, Scopus, Embase, and Web of Science from January 1913 to July 2021 to find the initial articles, from which data were extracted according to the set checklist in the data extraction stage. Finally, the studies were included in the present meta-analysis according to the inclusion and exclusion criteria, to be evaluated using the Newcastle Ottawa scale checklist. I Square and Q Cochrane were also used to assess the degree of heterogeneity. The analyses were performed using the random-effects model in STATA 16.

RESULTS

The results showed the quality score of the majority of cross-sectional studies included in the meta-analysis (62 studies) was equal to six or seven (moderate), and five ones had a high-quality score. After combining these studies, the pooled prevalence of depression among MSM in the world was 35% (95% CI 31%-39%, I square; 98.95%, P-value < 0.001). Population subgroup analysis showed the pooled prevalence of depression among MSM living with HIV was 47% (95% CI 39%-55%, I square; 95.76%, P-value < 0.001). Continent subgroup analysis showed the highest pooled prevalence of depression among Asian MSM at 37% (95% CI 31%-43%, I square; 99.07%, P-value < 0.001). Also, in the subgroup analysis of the sampling method, the pooled prevalence in the studies which used the respondent-driven sampling method was equal to 34% (95% CI 25%-43%, I square; 99.32%, P-value < 0.001). Sensitivity analysis revealed the pooled prevalence of depression in studies included in the meta-analysis was near or around the pooled estimate.

CONCLUSION

The pooled prevalence of depression among MSM was almost three times higher than the general male population. Therefore, particular and therapeutic interventions such as screening, and harm reduction programs for mental disorders, especially depression, are suggested to be considered in service packages.

Antimicrobial Resistance Trends of the Most Common Causative Pathogens Associated with Community-acquired Respiratory Infections in China: 2009–2018

Background

Emergence of antimicrobial resistance poses new challenges in the management of community acquired respiratory tract infections (CARTIs). Therefore, surveillance on the antimicrobial susceptibilities of common respiratory pathogens is valuable and guides empirical therapeutic choices in management of CARTIs.

Objective

The objective of the current study is to summarize the antimicrobial resistance trends in common respiratory tract pathogens isolated from patients with CARTIs in China, over a 10-year period (2009–2018).

Methods

Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis strains were collected from multicenter, and antimicrobial susceptibility testing was performed in the research central laboratory of each study period from 2009–2018. The pathogens that accounted for CARTIs in the adult population was considered and summarized.

Results

From 2009–2018 a total of 3750 isolates were collected from 22 cities located across different regions of China. Among these the most common bacterial isolates include S. pneumoniae (53.7%) followed by H. influenza (32.4%), M. catarrhalis (13.9%). S. pneumoniae exhibited reduction in susceptibility and increase in resistance to penicillin, cephalosporins (cefaclor, cefuroxime, ceftriaxone) during the surveillance period. Invasive and noninvasive S. pneumoniae showed similar resistance. In the case of H. influenzae susceptibility to β-lactam and β-lactamase inhibitors (ampicillin, amoxicillin and AMC), SXT, clarithromycin and cephalosporins (cefuroxime, cefaclor, ceftazidime) was reduced over the past 10 years with an exception of ceftriaxone. Overall, moxifloxacin and levofloxacin have the highest susceptibility rates against S. pneumoniae (>95%) and H. influenza (>90%). M. catarrhalis exhibited susceptibility to almost all the tested antimicrobials.

Conclusion

In China the 10-year trends showed a substantial increase in resistance to β-lactam drugs and reduction in sensitivity. However, certain antimicrobial agents namely fluoroquinolones including moxifloxacin and levofloxacin maintained low resistance rates with better susceptibility. Further, with few exceptions decline in susceptibility rates to macrolides and cephalosporins was observed among the tested pathogens.

Molecular Characterization of Penicillin-Binding Protein2x, 2b and 1a of Streptococcus pneumoniae Causing Invasive Pneumococcal Diseases in China: A Multicenter Study

Streptococcus pneumoniae is a common human pathogen that can cause severe invasive pneumococcal diseases (IPDs). Penicillin-binding proteins (PBPs) are the targets for β-lactam antibiotics (BLAs), which are the common empirical drugs for treatment of pneumococcal infection. This study investigated the serotype distribution and antibiotic resistance patterns of S. pneumoniae strains causing IPD in China, including exploring the association between penicillin (PEN) susceptibility and PBPs variations. A total of 300 invasive S. pneumoniae isolates were collected from 27 teaching hospitals in China (2010-2015). Serotypes were determined by Quellung reaction. Serotypes 23F and 19F were the commonest serotypes in isolates from cerebrospinal fluid (CSF), whilst serotypes 19A and 23F were most commonly seen in non-CSF specimens. Among the 300 invasive S. pneumoniae strains, only one strain (serotype 6A, MIC = 0.25 μg/ml) with PEN MIC value ≤ 0.25 μg/ml did not have any substitutions in the PBPs active sites. All the strains with PEN MIC value ≥ 0.5 μg/ml had different substitutions within PBPs active sites. Substitutions in PBP2b and PBP2x active sites were common in low-level penicillin-resistant S. pneumoniae (PRSP) strains (MIC = 0.5 μg/ml), with or without PBP1a substitution, while all strains with PEN MIC ≥ 1 μg/ml had substitutions in PBP1a active sites, accompanied by PBP2b and PBP2x active site substitutions. Based on the three PBPs substitution combinations, a high degree of diversity was observed amongst the isolates. This study provides some new insights for understanding the serology and antibiotic resistance dynamics of S. pneumoniae causing IPD in China. However, further genomic studies are needed to facilitate a comprehensive understanding of antibiotic resistance mechanisms of S. pneumoniae.

Multiplex polymerase chain reaction detection of Streptococcus pneumoniae and Haemophilus influenzae and their antibiotic resistance in patients with community-acquired pneumonia from southwest Iran

BACKGROUND

This study aimed to evaluate the occurrence of Streptococcus pneumoniae and Haemophilus influenzae in sputum of patients with community-acquired pneumonia (CAP) using culture and multiplex polymerase chain reaction (M-PCR) methods and to survey the antibiotic resistance patterns of aforesaid isolates.

RESULT

In total, 23.9 % (n = 22/92) of sputum samples showed positive results in the culture method. S. pneumoniae and H. influenzae were isolated from 15 (16.3 %) and 7 (7.6%) samples, respectively. Using M-PCR, 44 (47.8 %) samples were positive for S. pneumoniae and H. influenzae. Of these, S. pneumoniae and H. influenzae were detected in 33 (35.8%) and 11 (11.9%) of the sputum samples, respectively. The sensitivity, specificity, and accuracy rates of PCR in detection of S. pneumoniae in comparison with culture method were 100, 76.6, and 83.6%, respectively. While, the sensitivity, specificity, and accuracy rates of PCR in detection of H. influenzae in comparison with culture method were 100, 95.3, and 95.8%, respectively. Out of 11 isolates of H. influenzae, two strains confirmed as H. influenzae type b (Hib) and 3 isolates were type f. However, 6 isolates were non-typable. The co-trimoxazole and amoxicillin/clavulanate were the less effective antibiotics against S. pneumonia and H. influenzae, respectively. Ceftriaxone with 13.3% resistance rates was the most effective antibiotic against S. pneumoniae, while, clarithromycin, ceftriaxone, and gentamicin with resistance rates of 28.6% for each one were the most effective chemicals against H. influenzae isolates.

CONCLUSION

In this study, the prevalence of S. pneumoniae was more than H. influenzae using culture and M-PCR methods. The M-PCR provided better efficiency in detecting the bacterial agents in CAP patients compared to culture method. This method can improve the early detection of pathogens contributed to CAP. The drug resistant S. pneumoniae and H. influenzae indicated the need to develop a codified monitoring program to prevent further spread of these strains.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in the Philippines, 2012-2018

OBJECTIVE

Data are scarce on the prevailing Streptococcus pneumoniae serotypes in the Philippines, including the relative antimicrobial resistance (AMR) of these bacteria. This study is designed to fill that gap by describing the serotype distribution and AMR of S. pneumoniae in the Philippines from 2012 to 2018.

METHODS

S. pneumoniae isolates from clinical specimens were collected through the Philippine Department of Health Antimicrobial Resistance Surveillance Program from 1 January 2012 to 31 December 2018. Identification and antimicrobial susceptibility testing (AST) were performed using conventional and automated methods (Vitek2 Compact Automated Machine). AST for penicillin, erythromycin, co-trimoxazole, ceftriaxone and levofloxacin was done following the Clinical and Laboratory Standard Institute recommendations. Serotyping was done through slide agglutination following the Denka Seiken slide agglutination method.

RESULTS

From a total of 307 isolates of S. pneumoniae, 32 serotypes were identified; the most frequently occurring were serotypes 1, 3, 5, 4, 18, 19A, 6B, 15 and 14. Many (n = 113, 36.53%) of the isolates were from those aged £5 years. Pneumococcal conjugate vaccine (PCV) coverage was as follows: PCV7 (32.69%), PCV10 (54.16%) and PCV13 (69.23%). The overall AMR of invasive S. pneumoniae isolates was low. Penicillin-resistant serotypes were 14, 19, 24, 4, 5, 1, 15, 6 and 32.

DISCUSSION

With the inclusion of PCV13 in the National Immunization Program, continued monitoring of the prevailing serotypes of S. pneumoniae isolates in the Philippines is needed to guide disease and AMR control measures.

Clinical Features and Outcomes of Streptococcus pneumoniae Meningitis in Children: A Retrospective Analysis of 26 Cases in China

BACKGROUND

Streptococcus pneumoniae is an important cause of pediatric meningitis.

OBJECTIVE

The aim of this study was to analyze the clinical features and outcomes of children with pneumococcal meningitis at our hospital in China, so as to provide basis for improving the clinical treatment effect.

METHODS

This retrospective analysis included patients aged <16 years treated for pneumococcal meningitis at the Department of Neurology, Children's Hospital of Shanxi (January 2014-February 2016). Clinical data were extracted from the medical records. Patients were followed up for 6 months after discharge.

RESULTS

The analysis included 26 children aged 2 months to 13 years, with 17 (65.4%) aged <3 years. Presenting symptoms included fever (100%), lethargy (100%), impaired consciousness (88.5%), neck stiffness (69.2%), seizures (53.8%), and headache (50.0%). All patients had positive cerebrospinal fluid (CSF) cultures. The final treatment was vancomycin combined with a third-generation cephalosporin or other antibiotics in 25 patients. Eleven patients (42.3%) were recovered, 3 (11.5%) had neurological sequelae, and 12 (46.2%) died. Impaired consciousness (p = 0.035), cerebral hernia (p = 0.037), respiratory failure (p = 0.004), heart failure (p = 0.044), septic shock (p = 0.037), low CSF white blood cell count (p = 0.036), high CSF protein levels (p = 0.028), low white blood cell count (p = 0.036), and low blood neutrophil ratio (p = 0.016) are associated with a poor prognosis to pneumococcal meningitis.

CONCLUSION

Pneumococcal meningitis is associated with a poor prognosis in many children. Poor prognosis might be related to early ineffective antibiotic therapy, a combination of systemic failure, neurological problems, and changed inflammatory response. It is important to rapid initiation of appropriate antibiotic therapy if meningitis is suspected.

Is Penicillin-Nonsusceptible Streptococcus pneumoniae a Significant Challenge to Healthcare System? A Systematic Review and Meta-Analysis

BACKGROUND

In recent years, antibiotic-resistant pathogens including penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) have posed serious threats against human health. The aim of this meta-analysis was to investigate the prevalence of Streptococcus pneumoniae drug resistance particularly the incidence of PNSP strains in Iran.

METHODS

A systematic search was done in national and international electronic databases using Persian and English keywords. Up until May 20, 2020, a total of 58 publications were detected as eligible articles based on the inclusion and exclusion criteria, and then the selected studies were enrolled for data extraction and meta-analysis according to the PRISMA guidelines.

RESULTS

A high rate of PNSP (46.9%) and multidrug-resistant (MDR) S. pneumoniae (45.3%) in our isolates were evident. Furthermore, total frequency resistance to other drugs in S. pneumoniae was as follows: erythromycin 41.1%, azithromycin 53.2%, tetracycline 39.9%, levofloxacin 1.7%, rifampin 1.2%, clindamycin 31.7%, vancomycin 1.7%, trimethoprim/sulfamethoxazole 63.9%, chloramphenicol 20%, ceftriaxone 10.9%, amoxicillin 30.5%, ciprofloxacin 8.3%, imipenem 6.1%, linezolid 0%, and cefotaxime 8.3%.

CONCLUSION

Although the overall prevalence of cephalosporin- and carbapenem-resistant Streptococcus pneumoniae was low, penicillin-resistant strains, especially PNSP, could become a significant challenge to the healthcare system in Iran. Hence, the prescription of penicillin as the first-choice antibiotic in the treatment of S. pneumoniae infections should be avoided.

One cross-sectional investigation revealed that non-vaccine serotypes of Streptococcus pneumoniae could be identified more frequently in elderly Chinese people

OBJECTIVE

To analyze the serotype distribution and drug resistance of Streptococcus pneumoniae isolated from hospitalized patients of all ages in Zhongjiang county, Sichuan province, where the young children have just begun to vaccinate the PCV13 in private sector.

METHODS

Serotypes were determined for 387 isolates of S. pneumoniae by Quellung reaction. Antibiotic susceptibility was tested with the E-test or disc diffusion method.

RESULTS

The most common serotypes were type 19F and confirmed for 88 isolates (22.7%), followed by 19A (15.0%), 6B (7.8%), 16F (7.8%), 23F (7.0%) and 15A (4.4%). The coverage rates of PCV13 and PPSV23 were 63.3% and 65.1%. With the increase of age, the proportion of PCV13 types decreased significantly, from 71.3% (<2 years old) to 41.9% (≥60 years old). The intermediate rate and resistance rate of the isolates to oral penicillin were 48.6% and 45.2%, respectively. The resistance rate of erythromycin was high (94.4%). The PCV13 isolates was more resistant to penicillin than the non-PCV13 ones.

CONCLUSION

The PCV13 coverage rate in pediatric isolates was higher than those in adult isolates. The adults, especially the elderly, may be the reservoir of non-PCV13 types. It is necessary to investigate the serotype distribution of S. pneumoniae based on all age population to assess potential epidemics of non-vaccine serotype associated with PCVs administration.

Serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae isolates from a Phase III community-acquired bacterial pneumonia (CABP) trial

Objectives

To report Streptococcus pneumoniae serotyping and susceptibility data from a recent clinical trial (ML-3341-306) comparing delafloxacin with moxifloxacin in the treatment of adults with community-acquired bacterial pneumonia (CABP).

Methods

Serotyping and susceptibility testing were conducted on 142 baseline S. pneumoniae isolates recovered from subjects participating in a CABP clinical trial.

Results

Overall, 113/142 (79.6%) isolates were vaccine serotypes. 76.8% (109/142) of serotyped isolates were PPSV23 serotypes and 59.9% (85/142) of isolates were PCV13 serotypes. 15.5% (22/142) of serotyped isolates were serotypes not covered by either vaccine; 4.9% (7/142) of tested isolates were non-typeable. The most common serotypes were serotypes 3 (19.0%; 27/142), 19F (9.9%; 14/142) and 23F (7.0%; 10/142). All of the 142 isolates were susceptible to delafloxacin and moxifloxacin, 76.1% were susceptible to azithromycin and 71.8% were susceptible to penicillin. Multidrug resistance was found among 19A (4/5; 80%), 6A (1/4; 25%), 6B (1/4; 25%), 14 (1/4; 25%), 19F (1/14; 7.1%), and 23F serotypes (2/10; 20%), and among non-typeable S. pneumoniae isolates (1/7; 14.3%).

Conclusions

S. pneumoniae vaccine-targeted serotypes were the main cause of CABP in this Phase 3 CABP study. Fluoroquinolones including delafloxacin remain a good treatment option for CABP in adults caused by S. pneumoniae.

Antimicrobial susceptibility, serotype distribution, virulence profile and molecular typing of piliated clinical isolates of pneumococci from east coast, Peninsular Malaysia

Pilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.

Homology analysis of 51 penicillin-intermediate Streptococcus pneumoniae isolates from Wenzhou City, China

Objective

To investigate drug resistance features and homology among penicillin-intermediate Streptococcus pneumoniae isolates from Wenzhou City, China.

Methods

Fifty-one penicillin-intermediate S. pneumoniae isolates were obtained from respiratory samples of infants and children hospitalized with lung infections. An antimicrobial susceptibility test was used to assess drug resistance. Polymerase chain reaction and agarose gel electrophoresis were used to identify S. pneumoniae isolates and pulsed-field gel electrophoresis (PFGE) was used to analyze molecular subtypes. Hierarchical cluster analysis of PFGE fingerprints was used to compare genetic diversity and relatedness of S. pneumoniae isolates. The Quellung test was used for serotyping.

Results

Fifty-one penicillin-intermediate S. pneumoniae isolates showed evidence of multi-drug resistance and polyclonal origins. The isolates were classified into 25 subtypes through hierarchical cluster analysis of PFGE fingerprints. Three of these subtypes formed a supertype (15/51, 16/51 and 8/51 isolates), while the remaining subtypes occurred sporadically (12/51 isolates).

Conclusions

Transmission of penicillin-intermediate S. pneumoniae is mostly vertical and to a lesser extent horizontal. Effective prevention strategies, including respiratory tract management and contact isolation, are essential to control nosocomial S. pneumoniae infection. Once susceptibility is confirmed, vancomycin, high-dose penicillin or third-generation cephalosporins (cefotaxime and ceftriaxone) may be used to treat penicillin-intermediate S. pneumoniae.

Health and economic impact of the pneumococcal conjugate vaccine in hindering antimicrobial resistance in China

Antimicrobial resistance (AMR) poses a serious threat to global public health. However, vaccinations have been largely undervalued as a method to hinder AMR progression. This study examined the AMR impact of increasing pneumococcal conjugate vaccine (PCV) coverage in China. China has one of the world's highest rates of antibiotic use and low PCV coverage. We developed an agent-based DREAMR (Dynamic Representation of the Economics of AMR) model to examine the health and economic benefits of slowing AMR against commonly used antibiotics. We simulated PCV coverage, pneumococcal infections, antibiotic use, and AMR accumulation. Four antibiotics to treat pneumococcal diseases (penicillin, amoxicillin, third-generation cephalosporins, and meropenem) were modeled with antibiotic utilization, pharmacokinetics, and pharmacodynamics factored into predicting AMR accumulation. Three PCV coverage scenarios were simulated over 5 y: 1) status quo with no change in coverage, 2) scaled coverage increase to 99% in 5 y, and 3) accelerated coverage increase to 85% over 2 y followed by 3 y to reach 99% coverage. Compared to the status quo, we found that AMR against penicillin, amoxicillin, and third-generation cephalosporins was significantly reduced by 6.6%, 10.9%, and 9.8% in the scaled scenario and by 10.5%, 17.0%, and 15.4% in the accelerated scenario. Cumulative costs due to AMR, including direct and indirect costs to patients and caretakers, were reduced by $371 million in the scaled and $586 million in the accelerated scenarios compared to the status quo. AMR-reducing benefits of vaccines are essential to quantify in order to drive appropriate investment.

Serotype Distribution and Characteristics of the Minimum Inhibitory Concentrations of Streptococcus pneumoniae Isolated from Pediatric Patients in Kunming, China

Streptococcus pneumoniae (S. pneumoniae) is the main conditional pathogen of acute respiratory infection in infants, children, and older adults worldwide. It was great significant to identify the epidemic characteristics of serotypes and antibiotic susceptibility for the prevention and treatment of S. pneumoniae diseases. This research assessed the serotype distribution and the minimum inhibitory concentrations (MICs) of S. pneumoniae isolated from pediatric patients to provide information on the epidemiology and antibiotic resistance of S. pneumoniae in Kunming, China. A total of 140 S. pneumoniae isolates were collected from pediatric patients at Kunming Children's Hospital from January 2016 to October 2017. Serotype identification was done by Quellung reaction and multiplex polymerase chain reaction. MICs were determined by E-test. 140 isolates distributed in 13 types of serotypes. The top-three prevalent serotypes were 19F, 19A, and 6B. The immunization coverage rate of 13-valent pneumococcal conjugate vaccine (PCV) was relatively higher and should be introduced into the vaccination program in the region. MIC50 of penicillin, ceftriaxone, and levofloxacin was 1 μg/mL. MIC50 for meropenem and vancomycin was 0.38 μg/mL. MIC90 of penicillin, ceftriaxone, and levofloxacin was 1.5 μg/mL and that of meropenem and vancomycin was 0.5 μg/mL. The MIC90 of erythromycin was > 256 μg/mL. In summary, S. pneumoniae had low resistance rates to penicillin, ceftriaxone, levofloxacin, vancomycin, and meropenem, and these antibiotics could be the first-line agents for children with pneumococcal infections in Kunming.

Characterization of Blood-isolated, Penicillin-Nonsusceptible Streptococcus pneumoniae From Children Between 2014 and 2018 in Bojnurd, Iran

Background: Streptococcus pneumoniae is one of the common bacterial pathogens in pediatrics. In this study, we performed antimicrobial susceptibility testing, serotyping, and molecular typing of blood-isolated strains of pneumococci in Bojnurd. Objectives: In the current study, blood-isolated, penicillin-nonsusceptible S. pneumoniae strains were subjected to antimicrobial susceptibility testing and typing of capsular polysaccharides using the quelling reaction and PCR method, as well as genotyping using the Multi Locus Sequence Typing (MLST) method. Methods: In this study, 51 S. pneumoniae strains were isolated from blood samples of children less than five-years-old in 2014 - 2018. Antibiogram was performed using the Kirby-Bauer method. All of the isolates were serotyped by the Quelling reaction and PCR. The MLST method was applied to determine the molecular types. Results: Our study revealed that the most common serotypes of blood-isolated pneumococci were 19A, 6A/B, 1, 23F, 19F, 14, 15B/C, and 15A, and the common serotypes in Penicillin-nonsusceptible pneumococci (PNSP) isolates were 19F, 19A, 23F, 14, and finally 15A, 6A/B, 1, and 15B/C. The MLST analysis of PNSP isolates revealed that three highly resistant isolates with MIC ≥ 16 belonged to Sweden15A-25-19A (ST63), Taiwan19F-14-1 (ST236), and Taiwan19F-14 (ST236) clones. Conclusions: Regarding the common serotypes in this study, it seems that PCV-13 is a suitable choice for vaccination in this area. We also observed a high prevalence of PNSP and multi-drug resistant (MDR) strains between 2014 and 2018. It seems that the Taiwan19F-14 clone and its related STs played an essential role in the diffusion of antibiotic-resistant S. pneumoniae isolates in Bojnurd.

Large-scale survey of parental antibiotic use for paediatric upper respiratory tract infections in China: implications for stewardship programmes and national policy

BACKGROUND

Inappropriate use of antibiotics for upper respiratory tract infections (URTIs) in Chinese children is rampant. Parents' decision-making processes with respect to treatment choices and antibiotic use for paediatric URTIs were investigated to identify key constructs for effective interventions that target the public.

METHODS

Data were collected between June 2017 and April 2018 from a random cluster sample of 3188 parents of children aged 0-13 years across three Chinese provinces, representing different stages of economic development. Risk factors of parents' treatment choices and antibiotic use for paediatric URTIs were assessed using binary and multinomial logistic regressions, adjusting for socio-demographic characteristics.

RESULTS

A total of 1465 (46.0%) children of the 3188 parents who self-diagnosed their children with a URTI were given antibiotics, with or without prescription. Among these children, 40.5% were self-medicated with antibiotics by their parents and 56.1% obtained further antibiotic prescriptions at healthcare facilities. About 70% of children (n=2197) with URTI symptoms sought care; of these, 54.8% obtained antibiotic prescriptions and 7.7% asked for antibiotic prescriptions, with 79.4% successfully obtaining them. Those perceiving antibiotics as effective for treating the common cold and fever (adjusted odds ratio [aOR]=1.82[95% confidence interval, 1.51-2.19] and 1.77[1.47-2.13], respectively), who had access to non-prescription antibiotics (aOR=5.08[4.03-6.39]), and with greater perceived severity of infection (aOR=2.01[1.58-2.56]), were more likely to use antibiotics.

CONCLUSIONS

Multifaceted, context-appropriate interventions are vital to untangle the perpetual problem of self-medication, over-prescription and ill-informed demands for antibiotics. The findings in this study emphasise the need to prioritise interventions that enhance clinical training, neutralise the pressure from patients for antibiotics, educate on appropriate home care, discourage antibiotic self-medication and improve antibiotic dispensing.

Non-linear relationships between children age and pneumococcal vaccine coverage: Important implications for vaccine prevention strategies

BACKGROUND

Streptococcus pneumoniae (S. pneumoniae) is an important pathogen causing both invasive and non-invasive infections in children, with significant morbidity and mortality worldwide. This study aimed to determine the potential relationships between age and vaccine coverage and between multiple phenotype-genotype characteristics of S. pneumoniae isolated from children.

METHODS

All S. pneumoniae isolates were tested for antimicrobial susceptibility, virulence genes, serotypes, and sequence types. The restricted cubic spline models were used to reveal potential relationships between children age and pneumococcal vaccine coverage.

RESULTS

For capsular-based vaccines, we observed a high coverage rate of 13-valent pneumococcal conjugate vaccine (PCV13, 85.8%) and a significantly non-linear relationship between children age and vaccine coverage (including PCV7, PCV10, and PCV13), with marked fluctuations in children aged < 2 years. For protein-based and pilus-based vaccine candidates, we demonstrated dynamic non-linear relationships between age and vaccine coverage, maintaining a stable and high coverage rate of ply and lytA for all age groups. Moreover, there were significantly high-dimensional corresponding relationships among multiple phenotype-genotype characteristics of S. pneumoniae isolates (such as ST271 associated with serotype 19F, PI-2, and extensively drug-resistance).

CONCLUSIONS

Our findings suggest that the age for high PCV coverage being children aged ≥ 2 years and also provide important evidence for supporting ply and lytA as priority candidate targets for the development of new-generation protein vaccines.

Serotypes of Streptococcus pneumoniae in Children Aged <5 Years Hospitalized With or Without Pneumonia in Developing and Emerging Countries: A Descriptive, Multicenter Study

BACKGROUND

Improving knowledge regarding Streptococcus pneumoniae distribution in pneumonia cases is important to better target preventive and curative measures. The objective was to describe S. pneumoniae serotypes in children with or without pneumonia.

METHODS

It was a case-control study carried out in 8 developing and emerging countries between 2010 and 2014. Cases were children aged <5 years admitted to the hospital for pneumonia. Controls were children admitted for surgery or routine outpatient care.

RESULTS

In nasopharyngeal samples, S. pneumoniae were detected in 68.2% of the cases and 47.5% of the controls (P < .001). Nasopharyngeal carriage was associated with a higher risk of being a case in 6/8 study sites (adjusted odds ratio ranged from 0.71 [95% confidence interval [CI], .39-1.29; P = .26] in India [Pune/Vadu] to 11.86 [95% CI, 5.77-24.41; P < .001] in Mongolia). The 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were more frequently detected in cases with nasopharyngeal carriage (67.1%) than in controls with nasopharyngeal carriage (54.6%), P < .001. Streptococcus pneumoniae was detected in blood by polymerase chain reaction in 8.3% of the cases. Of 34 cases with an S. pneumoniae serotype detected in blood, 27 (79%) had the same serotype in the nasopharyngeal sample.

CONCLUSIONS

The results confirm the assumption that the isolate carrying or causing disease in an individual is of the same serotype. Most serotypes independently associated with nasopharyngeal carriage or pneumonia are covered by PCV13, suggesting that increased PCV coverage would reduce the burden of S. pneumoniae-related pneumonia.

Serotype distribution of Streptococcus pneumoniae isolated from children hospitalized in Beijing children's hospital (2013-2019)

BACKGROUND

Streptococcus pneumoniae can cause many infectious diseases among children, and relevant vaccines have not been scheduled into the National Immunization Program in China. The serotype distribution of Streptococcus pneumoniae is essential information used to evaluate the value of pneumococcal vaccines and formulate immunization strategies.

METHODS

Streptococcus pneumoniae isolates, identified as the disease pathogens, were collected from children hospitalized in Beijing Children's Hospital from 2013 to 2019. The serotype was detected by the Quellung reaction.

RESULTS

A total of 903 isolates of Streptococcus pneumoniae were collected, among which 809 were from non-invasive infections and 94 were from invasive infections. The non-invasive isolates were mainly isolated from respiratory secretions (49.4%) and bronchoalveolar lavage fluid (38.9%), while invasive isolates were from venous blood (5.4%), cerebrospinal fluid (2.8%) and pleural effusion (2.8%). The leading serotypes were 19F (36.0%), 19A (13.6%), 23F (9.4%), 14 (8.9%), 6A (6.9%), and 6B (5.3%). The overall coverage rates of 10-, 13-, 15-, 20-valent pneumococcal conjugate vaccines (PCV10, PCV13, PCV15, PCV20) and 23-valent pneumococcal polysaccharide vaccine (PPV23) as well as Pneumosil (a 10-valent pneumococcal conjugate vaccine) were 61.6%, 83.2%, 83.4%, 88.0%, 82.4% and 81.6%, respectively. The coverage rates of PCV13, PCV15 and PPV23 in isolates from invasive infections were significantly higher than those from non-invasive infections. The coverage rates of Pneumosil, either on the whole or among different age groups or different infections, were significantly higher than those of PCV10.

CONCLUSIONS

Serotypes 19F, 19A, 23F, 14, 6A and 6B were the most common types among the isolates. As for pneumococcal vaccines available now, the coverage rate of PCV13 was high, especially in isolates from invasive infections. The promotion of PCV13 or further high valent vaccines might be of greater benefit in preventing pneumococcal infections than other pneumococcal vaccines in children.

Investigation of Antibiotic Resistance, Serotype Distribution, and Genetic Characteristics of 164 Invasive Streptococcus pneumoniae from North China Between April 2016 and October 2017

BACKGROUND

Streptococcus pneumoniae infections are the major cause of global morbidity and mortality among children and patients aged more than 65 years. This study aimed to investigate the antimicrobial resistance, bacterial serotype distribution, and genetic characteristics of invasive S. pneumoniae from different cities in North China.

MATERIALS AND METHODS

A total of 164 invasive S. pneumoniae strains were collected from 8 hospitals in 5 regions of North China between April 2016 and October 2017. Minimum inhibitory concentrations (MICs) were determined using the agar dilution method. Capsular serotypes were identified using the Quellung reaction test. Molecular epidemiology was investigated using multilocus sequence typing.

RESULTS

S. pneumoniae isolates were highly resistant to macrolides, clindamycin, and tetracycline in all age groups. The overall rate of resistance to penicillin was 56.7%. However, fluoroquinolones and vancomycin maintained excellent antimicrobial activities. The rate of resistance to β-lactam in strains isolated from children aged less than 18 years was significantly higher than that in strains from other age groups. The most prevalent serotypes were 14 (22.6%), 19F (16.5%), non-vaccine types (14.0%), 19A (9.8%), and 23F (9.1%). The coverage for PCV10 and PCV13 was 59.8% and 75.6%, respectively. The vaccine coverage rate was the highest among children aged less than 5 years. The proportion of penicillin-resistant isolates was higher among vaccine-covered strains compared with non-covered strains. S. pneumoniae showed considerable clonal dissemination, and ST876 (28, 17.1%), ST271 (22, 13.4%), ST81 (17, 10.4%) and ST320 (14, 8.5%) were the major STs.

CONCLUSION

All the 164 invasive S. pneumoniae isolates demonstrated high resistance to antibiotics. The coverage of S. pneumoniae vaccine was higher in children than in adults.

Whole genome sequencing of macrolide resistant Streptococcus pneumoniae serotype 19A sequence type 416

Background

The resistance of Streptococcus pneumoniae to macrolides is becoming an increasingly important issue and thus it is important to understand the genetics related to adaptation of this species to the widespread use of antibiotics in Europe. The 58 isolates of S. pneumoniae belonging to sequence type (ST) 416 and serotype 19A and to several different phenotypes originated from Italy, Portugal and Czech Republic were thus sequenced on Illumina MiSeq. The aim of the study was to describe genetical origine of isolates, investigate their macrolide resistance and suggest reasons for spread of ST416 in the Czech Republic.

Results

Investigation of genes associated with serotype determined serotype switch between 15B and 19A serotypes and core genome multilocus sequence typing (cgMLST) confirmed the origine of concerned isolates in Netherlands^15B-37 clone. Inspected genomes proved variability of genes associated with the macrolide resistance even within closely genetically relative isolates.

Conclusions

Participation of 19A/ST416 on the spread of Netherlands^15B-37 is accompanied by serotype switch between 19A and 15B serotypes and with acquisition of genes involved in macrolide resistance to the clone that was originally macrolide susceptible. There is evident tendency to interchanging and modifications of these and surrounding genes, that could lead to accelerate spreading of this sequence type in regions with high macrolide consumption.

Molecular Detection and Serotyping of Streptococcus pneumoniae in Children with Suspected Meningitis in Northeast Iran

Background:

To date, more than 90 Streptococcus pneumoniae (S. pneumoniae) capsular serotypes are known. The prevalence of these serotypes varies according to the geographical area and the regional vaccination program. Due to the lack of regular vaccination programs for S. pneumoniae in developing countries, serotyping of the prevalent isolates is useful in selecting the correct vaccine. The present study aimed to evaluate common serotypes of pneumococcal meningitis in Bojnurd, Iran.

Methods:

All cerebrospinal fluid (CFS) samples suspected for bacterial meningitis were analyzed. The samples were collected during 2014-2018 in the Laboratory of Imam Reza Hospital (Bojnurd, Iran). Due to the high rate of false-negative cultures, polymerase chain reaction (PCR) was used for the detection of lytA and psaA genes of S. pneumoniae. In addition, the modified Marimon’s PCR method was used for serotyping the bacteria. The data were analyzed using Pearson’s Chi-square test.

Results:

Out of the 901 CSF samples, 106 cases tested positive for S. pneumoniae using the PCR method, while only 92 cases tested positive using the conventional methods. Based on the Marimon’s PCR method, serotypes 23F, 19F, 19A, 1, 14, and serogroup 6A/B were the most common types. Serogroups 18C, 15A/F, 15B/C, 9A/V, 7A/F, 11A/D/F, and 22A/F were also detected in isolates. Note that 2.8% of the samples were non-typable (NT).

Conclusion:

The results showed that only 13 serotypes were responsible for all meningitis cases. Pneumococcal capsular vaccine-13 (PCV-13) is the preferred choice against common serotypes of S. pneumoniae in northeast Iran.

The abstract was presented in Iran’s 19^th International Congress of Microbiology, as a poster and published in the congress abstracts book.

Exploration of Binding Mechanism of a Potential Streptococcus pneumoniae Neuraminidase Inhibitor from Herbaceous Plants by Molecular Simulation

Streptococcus pneumoniae can cause diseases such as pneumonia. Broad-spectrum antibiotic therapy for Streptococcus pneumoniae is increasingly limited due to the emergence of drug-resistant strains. The development of novel drugs is still currently of focus. Abundant polyphenols have been demonstrated to have antivirus and antibacterial ability. Chlorogenic acid is one of the representatives that has been proven to have the potential to inhibit both the influenza virus and Streptococcus pneumoniae. However, for such a potential neuraminidase inhibitor, the interaction mechanism studies between chlorogenic acid and Streptococcus pneumoniae neuraminidase are rare. In the current study, the binding mechanism of chlorogenic acid and Streptococcus pneumoniae neuraminidase were investigated by molecular simulation. The results indicated that chlorogenic acid might establish the interaction with Streptococcus pneumoniae neuraminidase via hydrogen bonds, salt bridge, and cation-π. The vital residues involved Arg347, Ile348, Lys440, Asp372, Asp417, and Glu768. The side chain of Arg347 might form a cap-like structure to lock the chlorogenic acid to the active site. The results from binding energy calculation indicated that chlorogenic acid had strong binding potential with neuraminidase. The results predicted a detailed binding mechanism of a potential Streptococcus pneumoniae neuraminidase inhibitor, which will be provide a theoretical basis for the mechanism of new inhibitors.

Serotype Distribution, Antimicrobial Susceptibility, and Multilocus Sequencing Type (MLST) of Streptococcus pneumoniae From Adults of Three Hospitals in Shanghai, China

Background:Streptococcus pneumoniae, a main causative agent associated with invasive and non-invasive infection in elderly population, is a major global health problem. After pneumococcal conjugate vaccines (PCV) and pneumococcal polysaccharide vaccines (PPV) were introduced, the distribution of S. pneumoniae serotypes has changed. There was currently limited data on epidemiology and status of antimicrobial resistance of S. pneumoniae in Shanghai.

Objective: To determine the serotype distribution, antimicrobial susceptibility and molecular epidemiology of S. pneumoniae isolated from adults in Shanghai.

Method: A total of 75 S. pneumoniae isolates consecutively collected from 2015 through 2017 were serotyped by conventional multiplex-PCR. The antimicrobial susceptibility was determined by broth microdilution method. The multilocus sequence type (MLST) was performed to estimate the molecular epidemiology.

Results: The predominant serotypes among the isolates were 19F (20.00%), 3 (16.00%), 23F (9.33%), 14 (8.00%), and19A (5.33%). The prevalence of pneumococcal strains with serotypes targeted by vaccines PCV7, PCV10, PCV13, and PPV23 was 44, 45.33, 66.67, and 80%, respectively. Penicillin non-susceptible S. pneumoniae (PNSSP) accounted for 16% of the isolates examined and resistance to erythromycin, azithromycin, tetracycline, clindamycin, cefaclor and trimethoprim-sulfamethoxazole were found in 92.00, 90.67, 86.67, 81.33, 54.67, and 54.67% of isolates, with most isolates (78.67%) presenting multidrug-resistance. The top three sequence types (STs) were ST271 (17.33%), ST180 (9.33%), and ST81 (8.00%). The international resistance clone complexes Spain^23F-1 (n = 4), Netherland³-31 (n = 8), and Taiwan^19F-14 (n = 14) were identified.

Conclusions: The S. pneumoniae isolates showed high genetic diversity in Shanghai and the prevalence of antimicrobial resistance was also high among S. pneumoniae isolates, most of which were multidrug-resistant. The spread of international resistance clones might contribute to the increase of resistant isolates. The PPV23 could protect against most pneumococcal capsular serotypes causing infection of adults in Shanghai.

Molecular serotyping and genotyping of penicillin non-susceptible pneumococci: the introduction of new sequence types, Tehran, Iran

The emergence of penicillin non-susceptible Streptococcus pneumoniae (PNSP) isolates can pose significant challenges to today's health-care system. Resistant clonal isolates are disseminated in different regions and countries, and this study was focused on the description of the epidemiological spread of these strains. Clinical samples were collected from individuals admitted to hospitals affiliated to the Tehran University of Medical Sciences, Iran. To investigate the molecular characteristics of PNSP isolates, they were subjected to molecular typing using multi-locus sequence typing (MLST). Serotype distributions of S. pneumoniae isolates were also evaluated by multiplex PCR assay. The most prevalent serotypes in the PNSP isolates were 23F, 19F, 14, 3 and 9V. Two isolates were considered as a non-vaccine serotype. The MLST analysis showed that PNSP isolates belonged to five different clonal complexes (CC180, CC217, CC81, CC63 and CC320) and 42% (5/12) of the sequence types were novel (12936, 12937, 12938, 12939 and 12940). This study indicates the high level of heterogeneity that is present among PNSP isolates. Unexpected high genetic diversity in small populations indicates consecutive diversification of resistant strains.

Epidemiology Characteristics of Streptococcus pneumoniae From Children With Pneumonia in Shanghai: A Retrospective Study

Background: Streptococcus pneumoniae is the most common pathogen causing death in children under 5 years old. This retrospective surveillance aimed to analyze serotype distribution, drug resistance, virulence factors, and molecular characteristics of pneumonia isolates from children in Shanghai, China. Methods: A total of 287 clinical pneumococcal isolates were collected from January to December in 2018 and were divided into community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HAP) two groups according to where someone contracts the infection. All isolates were serotyped by multiplex sequential PCR and antimicrobial susceptibility testing was performed using E-test or disk diffusion method. The molecular epidemiology was analyzed using multilocus sequence typing and seven housekeeping genes were sequenced to identified the sequence types (STs). In addition, we investigated the presence of virulence genes via PCR. Results: The most common serotypes were 19F, 6A, 19A, 23F, 14, and 6B, and the coverage rates of the 7-, 10- and 13-valent pneumococcal conjugate vaccines were 58.9, 58.9, and 80.5%, respectively. More PCV13/non-PCV7 serotypes and higher rate of penicillin non-susceptible S. pneumoniae were seen in HAP. Molecular epidemiological typing showed a high level of diversity and five international antibiotic-resistant clones were found, including Taiwan^19F-14, Spain^23F-1, Spain^6B-2, Taiwan^23F-15 and Sweden^15A-25. No significant difference was observed in the presence of virulence genes among the isolates obtained from CAP and HAP. All of the S. pneumoniae isolates carried lytA, ply, psaA, pavA, spxB, htrA, and clpP, and the carriage rate of nanA and piaA were 96.2 and 99.0%. Conversely, cps2A, cbpA, and pspA were present in 33.8-44.3% of the isolates. Conclusions: Serotype changes and emerging multidrug-resistant international clones were found in current study. lytA, ply, psaA, pavA, spxB, htrA, and clpP may be good protein vaccine candidates. Long-term high-quality surveillance should be conducted to assess impact and effectiveness brought by vaccines, and provide a foundation for prevention strategies and vaccine policies.

Antimicrobial susceptibility among Streptococcus pneumoniae and Haemophilus influenzae collected globally between 2015 and 2017 as part of the Tigecycline Evaluation and Surveillance Trial (TEST)

Purpose: In order to understand the prevalence of Streptococcus pneumoniae and Haemophilus influenzae globally and provide the basis for rational use of antimicrobials in clinical settings, in vitro activity of tigecycline and comparative agents was evaluated against 3929 S. pneumoniae and 4043 H. influenzae isolates obtained from 150 centers globally between 2015 and 2017 as a part of the Tigecycline Evaluation and Surveillance Trial (TEST).

Methods: Broth microdilution methods were performed to determine the minimum inhibitory concentration (MIC) of the isolates according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). The CLSI breakpoint was used to determine antimicrobial susceptibilities, except for that of tigecycline, for which the US Food and Drug Administration (FDA) breakpoints were used.

Results: More than 99% of S. pneumoniae isolates were susceptible to vancomycin (100%), linezolid (100%), tigecycline (99.9%), and levofloxacin (99.1%). Macrolides (erythromycin, azithromycin, and clarithromycin, 67.1–69.4% susceptibility globally) and penicillin (61.7% in globally) were the drugs with more resisitance to S. pneumoniae. Penicillin-intermediate and -resistant isolates were found in 24.8% and 13.6% of S. pneumoniae isolates. H. influenzae was highly susceptible (>98.7%) to all antibiotics tested except for ampicillin, for which susceptibility was 76.1%. The number of drugs with the lowest susceptibility calculated in Asia were far more than other regions, with 61.5% (8 in 13 drugs) in S. pneumoniae and 70.0% (7 in 10 drugs) in H. influenzae, respectively.

Conclusions: Vancomycin, linezolid, tigecycline, and levofloxacin can be used as the first choice in the empirical therapy of infection disease caused by S. pneumoniae. But macrolides and penicillin should be used prudently in treatment of the infection caused by S. pneumoniae, as well as ampicillin treat the infection caused by H. influenzae. Asia was the region with the most severe resistance in S. pneumoniae and H. influenzae.

Nasopharyngeal Carriage of Antimicrobial-Resistant Pneumococci in an Intensively Sampled South African Birth Cohort

Introduction: Nasopharyngeal (NP) colonization by Streptococcus pneumoniae (pneumococcus) precedes the development of respiratory tract infection. Colonization by antimicrobial-resistant pneumococci, especially in infants, is a major public health concern. We longitudinally investigated antimicrobial-resistance amongst pneumococci colonizing the nasopharynx of South African infants immunized with the 13-valent pneumococcal conjugate vaccine (PCV13).

Methods: NP swabs were collected every second week from birth through the first year of life from 137 infants. Pneumococci were identified and serotyped using conventional microbiological techniques, and their antibiotic susceptibility profiles determined by disk diffusion and E-test.

Results: All infants were immunized with 3 doses of PCV13. 1520 pneumococci (760 non-repeat) isolates were recovered from 137 infants; including non-typeable (n = 99), PCV13 (n = 133) and non-PCV13 serotypes (n = 528). The prevalence of penicillin, erythromycin, and cotrimoxazole non-susceptibility was 19% (95% CI 17–22%) (3% fully resistant), 18% (95% CI 15–21%) (14% fully resistant), and 45% (95% CI 42–49%) (36% fully resistant), respectively. The predominant penicillin-non-susceptible serotypes included 19A, 19F, 15B/15C, 15A, and 21, while susceptible serotypes included 23A, 34, and 17A. Multidrug-resistance (MDR) was observed in 9% (95% CI 7–11%) of the isolates. PCV13 serotypes were more likely to be non-susceptible, compared to non-PCV13 serotypes, to penicillin (26% vs. 16%, p = 0.007), erythromycin (23% vs. 15%, p = 0.027) and cotrimoxazole (62% vs. 41%, p < 0.001). Non-susceptibility to penicillin, erythromycin, and cotrimoxazole remained relatively constant through the first year of life (X² test for trend: p = 0.184, p = 0.171, and p = 0.572, respectively). Overall, penicillin or erythromycin-non-susceptible pneumococci were carried for a shorter duration than susceptible pneumococci [penicillin (mean days, 18 vs. 21, p = 0.013) and erythromycin (mean days, 18 vs. 21, p = 0.035)]. Within individual infants carrying the same serotype longitudinally, changes in antibiotic susceptibility were observed over time in 45% (61/137) of infants and these changes were predominantly for penicillin (76%, 79/104).

Conclusion: Prevalence of NP carriage with antibiotic-non-susceptible pneumococci was relatively constant throughout the first year of life. PCV13 serotypes were more commonly non-susceptible to penicillin, erythromycin, and cotrimoxazole. Penicillin or erythromycin-non-susceptible pneumococci were carried for a shorter duration than penicillin or erythromycin-susceptible pneumococci.

Etiology of acute otitis media and phenotypic-molecular characterization of Streptococcus pneumoniae isolated from children in Liuzhou, China

Background

The etiology and epidemiology of acute otitis media (AOM) are poorly understood in China. This study aimed to describe the etiology of AOM and the phenotypic and molecular characteristics of AOM-causing Streptococcus pneumoniae (S.pneumoniae) recovered from Chinese children.

Methods

A retrospective study was conducted to enrol patients younger than 18 years diagnosed as AOM. Middle ear fluid specimens were collected then cultured for bacterial pathogens. All S.pneumoniae isolates were tested for antibiotic susceptibility, serotypes, virulence genes, antibiotic resistant determinants and sequence types.

Results

The dominant otopathogen among AOM children was S.pneumoniae (54.4%). Among S.pneumoniae isolates, there were 97.3, 97.3 and 75.7% isolates resistant to erythromycin, tetracycline and trimethoprim-sulfamethoxazole, respectively. There was 72.8% S.pneumoniae with multidrug resistance. The dominant sequence types (STs) were ST271 and ST320, whereas the prevailing serotypes were 19F and 19A. The 7-valent and 13-valent pneumococcal conjugate vaccine (PCV) coverage among AOM children were 73.0 and 94.6%, respectively. Additionally, we found that CC271 expressed more of mef(A/E) (P < 0.001), pspA (P = 0.022) and sipA (P < 0.001) than non-CC271 isolates.

Conclusion

The high prevalence of international multidrug-resistant clone (Taiwan^19F-14) in China necessitates continued dedication to expand PCV13 immunization and better control of antibiotic use in China.

Enzymatic Hydrolysis of Pneumococcal Capsular Polysaccharide Renders the Bacterium Vulnerable to Host Defense

Despite a century of investigation, Streptococcus pneumoniae remains a major human pathogen, causing a number of diseases, such as pneumonia, meningitis, and otitis media. Like many encapsulated pathogens, the capsular polysaccharide (CPS) of S. pneumoniae is a critical component for colonization and virulence in mammalian hosts. This study aimed to evaluate the protective role of a glycoside hydrolase, Pn3Pase, targeting the CPS of type 3 S. pneumoniae, which is one of the most virulent serotypes. We have assessed the ability of Pn3Pase to degrade the capsule on a live type 3 strain. Through in vitro assays, we observed that Pn3Pase treatment increases the bacterium's susceptibility to phagocytosis by macrophages and complement-mediated killing by neutrophils. We have demonstrated that in vivo Pn3Pase treatment reduces nasopharyngeal colonization and protects mice from sepsis caused by type 3 S. pneumoniae Due to the increasing shifts in serotype distribution, the rise in drug-resistant strains, and poor immune responses to vaccine-included serotypes, it is necessary to investigate approaches to combat pneumococcal infections. This study evaluates the interaction of pneumococcal CPS with the host at molecular, cellular, and systemic levels and offers an alternative therapeutic approach for diseases caused by S. pneumoniae through enzymatic hydrolysis of the CPS.