Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing invasive pneumococcal disease from 2009–2012 with an emphasis on serotype 19A in bacteraemic pneumonia and empyema and β-lactam resistance

National surveillance of antimicrobial susceptibilities to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics and serotype distribution of invasive Streptococcus pneumoniae isolates in adults: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) programme in 2017-2020

Objectives

The aim of this study was to investigate the trends in serotypes and in vitro antimicrobial susceptibility of Streptococcus pneumoniae causing adult invasive pneumococcal disease (IPD) to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics from 2017–2020 following implementation of the 13-valent pneumococcal conjugate vaccine (PCV-13) and during the COVID-19 (coronavirus disease 2019) pandemic.

Methods

During the study period, 237 S. pneumoniae isolates were collected from non-duplicate patients, covering 15.0% of IPD cases in Taiwan. Antimicrobial susceptibility testing was performed using a Sensititre® system. A latex agglutination method (ImmuLex™ Pneumotest Kit) was used to determine serotypes.

Results

Susceptibility rates were high for vancomycin (100%), teicoplanin (100%) and linezolid (100%), followed by ceftaroline (non-meningitis) (98.3%), moxifloxacin (94.9%) and quinupristin/dalfopristin (89.9%). MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline and omadacycline were generally low. Non-vaccine serotype 23A was the leading cause of IPD across the adult age range. Isolates of serotype 15B were slightly fewer than those of PCV-13 serotypes in patients aged ≥65 years. The overall case fatality rate was 15.2% (36/237) but was especially high for non-PCV-13 serotype 15B (21.4%; 3/14). Vaccine coverage was 44.7% for PCV-13 and 49.4% for the 23-valent pneumococcal polysaccharide vaccine (PPSV-23), but was 57% for both PCV-13 and PPSV-23.

Conclusion

The incidence of IPD was stationary after PCV-13 introduction and only dramatically decreased in the COVID-19 pandemic in 2020. The MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline, omadacycline were generally low for S. pneumoniae causing adult IPD.

Clinical characteristics and serotype distribution of invasive pneumococcal disease in pediatric patients from Beijing, China

Invasive pneumococcal disease (IPD) is associated with significant morbidity and mortality. However, limited studies have reported clinical features of IPD cases among Chinese children. This study aimed to evaluate clinical characteristics as well as serotype distribution of hospitalized IPD children in Beijing, China. Children with confirmed IPD were retrospectively recruited from January 2014 to December 2019. Clinical data were gathered from medical records, and serotypes of Streptococcus pneumoniae isolates were detected. Clinical differences between deaths and survivors were also compared, and risk factors associated with death were determined. Of sixty-eight children diagnosed with IPD, 58 (85.3%) were < 5 years. 19F was the predominant serotype (23, 33.8%), followed by 19A (14, 20.6%), 14 (12, 17.6%), 23F (5, 7.4%), and non-vaccine serotype (NVT) 15A (3, 4.4%). The coverage rate of 13-valent pneumococcal conjugate vaccine (PCV) was 92.6% (63). After introduction of PCV-13, there was a significant increase of IPD due to NVTs (p = 0.047). Sixteen (23.5%) children died, and diagnoses of 11 (68.8%) were meningitis. Risk factors for death were < 2 years (odds ratio [OR] [95% confidence interval {CI}]: 6.64 [1.14-32.10]; p = 0.019), altered mental status (OR [95%CI]: 10.10 [2.11-48.31]; p = 0.004), and septic shock (OR [95%CI]: 6.61 [1.11-39.50]; p = 0.038). This study revealed that the case fatality rate of hospitalized IPD children was high in this hospital. Fatal cases were more likely to be children < 2 years, presented with changed mental status and septic shock. Notably, we found that NVTs increased after PCV13 availability in China.

Emergence of serotype 19A Streptococcus pneumoniae after PCV10 associated with a ST320 in adult population, in Porto Alegre, Brazil

Use of pneumococcal conjugate vaccines has caused emergence of non-vaccine serotypes. No Brazilian data specifically about serotype 19A are available. We aimed to evaluate the frequency of occurrence, susceptibility profile and molecular epidemiology of serotype 19A before and after vaccine introduction in Brazil. Pneumococcal identification was performed by the conventional method. Strain serotype was determined by multiplex polymerase chain reaction (PCR) and/or Quellung reaction. Resistance was determined by Etest^® and PCR was performed to determine the presence of macrolide resistance genes, ermB and/or mefA. Pneumococci were typed by Multilocus Sequence Typing. Thirty-eight serotype 19A Streptococcus pneumoniae were recovered, mostly from invasive diseases. Prevalence of serotype 19A increased following vaccination (from 3.5% before vaccination to 8.1% after, p = 0.04196). Non-susceptibility increased to most antimicrobials after vaccine introduction and was associated with clonal complex (CC)320. MLST showed nine different STs, which were grouped in one main CC: CC320 (63.9%). During the post-vaccination era, the frequency of this serotype increased significantly from 1.2% in 2011 to 18.5% in 2014 (p = 0.00001), with a concomitant decrease in the genetic variability: ST320 consistently predominated after vaccine-introduction (61.1%). Overall, our results showed a post-PCV10 increase in the frequency of serotype 19A. This was accompanied by a selection of CC320 and antimicrobial resistance.

Changing Epidemiology and Predisposing Factors for Invasive Pneumococcal Disease at Two Australian Tertiary Hospitals

BACKGROUND

Invasive pneumococcal disease (IPD) is associated with significant morbidity and mortality in children. Universal pneumococcal conjugate vaccination has changed the epidemiology of IPD. In vaccinated children, IPD can be a marker of an underlying immunodeficiency.

METHODS

This is a retrospective audit of children younger than 18 years with IPD admitted to 2 tertiary pediatric hospitals in Australia between 2011 and 2017. Data on predisposing conditions, immunologic evaluation, pneumococcal serotype, antibiotic susceptibility and treatment were collected.

RESULTS

During the 7-year period, there were 131 presentations with IPD in 127 children; 3 children had recurrent IPD. Patients presented with sepsis (41%), empyema (29%), meningitis (18%), mastoiditis (12%), pneumonia (10%) and septic arthritis (4%). In 19 (15%) presentations, risk factors for IPD were present, including malignancy, hematologic disorder, chronic liver disease, chronic kidney disease and cochlear implant. Pneumococcal serotypes were determined in 78/131 (60%) of presentations: the most frequent serotypes were 19A (19%), 3 (13%), 7F (10%) and 19F (8%) and non-vaccine serotypes 22F (8%), 35B (6%), 15A (4%) and 38 (4%). Overall, 11% of isolates were non-susceptible to ceftriaxone. Only 36 patients (32%) had an immunologic evaluation, and 4 patients had proven or probable immunodeficiency.

CONCLUSION

Although pneumococcal conjugate vaccine serotypes 19A, 3, 19F and 7F remain frequent causes of IPD, non-vaccine serotypes are emerging. Our data support vancomycin treatment for children with pneumococcal meningitis given 11% of our isolates were not susceptible to ceftriaxone. It is important to consider underlying conditions predisposing to IPD in a population with high rates of pneumococcal vaccination.

Recommendations and guidelines for the treatment of pneumonia in Taiwan

Pneumonia is a leading cause of death worldwide, ranking third both globally and in Taiwan. This guideline was prepared by the 2017 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group, formed under the auspices of the Infectious Diseases Society of Taiwan (IDST). A consensus meeting was held jointly by the IDST, Taiwan Society of Pulmonary and Critical Care Medicine (TSPCCM), the Medical Foundation in Memory of Dr. Deh-Lin Cheng, the Foundation of Professor Wei-Chuan Hsieh for Infectious Diseases Research and Education and CY Lee's Research Foundation for Pediatric Infectious Diseases and Vaccines. The final guideline was endorsed by the IDST and TSPCCM. The major differences between this guideline and the 2007 version include the following: the use of GRADE methodology for the evaluation of available evidence whenever applicable, the specific inclusion of healthcare-associated pneumonia as a category due to the unique medical system in Taiwan and inclusion of recommendations for treatment of pediatric pneumonia. This guideline includes the epidemiology and recommendations of antimicrobial treatment of community-acquired pneumonia, hospital-acquired pneumonia, ventilator-associated pneumonia, healthcare-associated pneumonia in adults and pediatric pneumonia.

Characterisation of Streptococcus pneumoniae isolates from invasive disease in adults following the introduction of PCV10 in Brazil

Purpose. Invasive pneumococcal disease (IPD) in the elderly is an important public health issue due to the increased proportion of this population in many countries including Brazil. We aimed to characterise pneumococci isolates in adults >50 years with IPD, following the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) as part of the National Childhood Immunisation Program for children ≤2 years in March 2010.Methodology. Between 2013 and 2015, pneumococcal isolates were collected and serotypes were determined using multiplex PCR and/or Quellung reaction. Antimicrobial susceptibility was defined by E-test (bioMérieux); genetic diversity was determined using Multiple-Locus Variable Number Tandem Repeat Analysis (MLVA) and, in selected isolates, Multi Locus Sequence Typing (MLST) was performed.Results/Key findings. Among 102 pneumococcal isolates, the most frequent serotypes were 19A, 13 of 102 (12.7 %) and 22F, 10 of 102 (9.8 %). Ninety-eight isolates were tested for antimicrobial susceptibility. Intermediate resistance to penicillin was present in 2/98 (2.0 %), ceftriaxone in 7/98 (7.1 %) and meropenem in 7/95 (7.4 %) of the isolates (non-meningitis breakpoint: 4 µg ml^-1/2 µg ml^-1/0.5 µg ml^-1, respectively). Resistance to penicillin (meningitis breakpoint ≥0.12 µg ml^-1) was observed in 31/98 (31.6 %) of the isolates. Genetic analysis presented two relevant clonal groups, belonging to non-PCV10 serotypes: 19A (ST320, linked to non-susceptibility) and 22F (ST6403).Conclusion. Our data suggest a predominance of non-PCV10 serotypes among IPD in the elderly population in circulating strains ca. 3 to 5 years after the introduction of PCV10 in Brazil.

Invasive pneumococcal disease caused by ceftriaxone-resistant Streptococcus pneumoniae in Taiwan

BACKGROUND

Invasive pneumococcal disease (IPD) was associated with mortality, but the risk factors associated with mortality remains controversial.

METHODS

A retrospective cohort study was designed. All patients with IPD from 2011 to 2013 admitted in a medical center were screened and collected for their clinical presentations and laboratory characteristics.

RESULTS

Approximately half of the 134 IPD isolates derived from these patients belonged to three major serotypes (19A, 6A and 3), which are included in 13-valent pneumococcal conjugate vaccine (PCV13), but not in 7-valent pneumococcal conjugate vaccine (PCV7). Ceftriaxone resistance according to non-meningitis criteria was identified in 38% of the IPD isolates, and was the major independent risk factor associated with inappropriate initial therapy that subsequently contributed to mortality of the patients. Infection by serotype 6A, 15B, 19A, 19F, or 23F was the major independent risk factor associated with ceftriaxone resistance (non-meningitis criteria). 77.6% of these isolates belonged to additional PCV13 serotypes, with more than 40% expressing resistance to ceftriaxone. In terms of serotype coverage, PCV13 covered 94.1% of the IPD isolates with ceftriaxone resistance, in comparison to 21.6% only by PCV7.

CONCLUSIONS

The increase of ceftriaxone resistance in pneumococci in part driven by PCV7 vaccination in Taiwan is worrisome. The use of PCV13 in children as well as in the elderly population is likely to offer protection from the infection caused by ceftriaxone-resistant pneumococci. It is important to give an effective drug such as penicillin, fluoroquinolones or vancomycin in 2 days for improving outcome of IPD patients.

Community-Acquired Pneumonia in the Asia-Pacific Region

Community-acquired pneumonia (CAP) is an important cause of mortality and morbidity worldwide. Aging population, dense urbanization, and poor access to health care make the Asia-Pacific region vulnerable to CAP. The high incidence of CAP poses a significant health and economic burden in this region. Common etiologic agents in other global regions including Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydophila pneumoniae, Staphylococcus aureus, and respiratory viruses are also the most prevalent pathogens in the Asia-Pacific region. But the higher incidence of Klebsiella pneumoniae and the presence of Burkholderia pseudomallei are unique to the region. The high prevalence of antimicrobial resistance in S. pneumoniae and M. pneumoniae has been raising the need for more prudent use of antibiotics. Emergence and spread of community-acquired methicillin-resistant S. aureus deserve attention, while the risk has not reached significant level yet in cases of CAP. Given a clinical and socioeconomic importance of CAP, further effort to better understand the epidemiology and impact of CAP is warranted in the Asia-Pacific region.

Streptococcus pneumoniae Serotype Distribution and Pneumococcal Conjugate Vaccine Serotype Coverage among Pediatric Patients in East and Southeast Asia, 2000-2014: a Pooled Data Analysis

Pneumococcal infection is one of the leading causes of death worldwide, especially in children of developing and underdeveloped countries. Capsular polysaccharide-based vaccines are available for the prevention of this disease. A 7-valent pneumococcal conjugate vaccine (PCV7) was licensed in 2000 for use in children less than two years of age. Subsequently, to broaden the protection, 10-valent (PCV10) and 13-valent (PCV13) vaccines were licensed in 2009 and 2010, respectively. All of these conjugate vaccines elicit an immune response that only provides protection against the infection of S. pneumoniae serotypes included in the formulation. Profiles of S. pneumoniae serotype distribution and serotype coverage for both PCV7 and PCV13 have been reported in some Asian countries/territories. But the published results cannot provide conclusive information due to the difference in studied population and geographic areas. The goals of this review are to obtain an accurate estimate of serotype coverage for PCV7, PCV10, and PCV13 and examine the change in the S. pneumoniae serotype distribution after PCV7 use among pediatric patients in East and Southeast Asia through the analysis of pooled data that were published in the English literature between 2000 and 2014.

Evolving pneumococcal serotypes and sequence types in relation to high antibiotic stress and conditional pneumococcal immunization

In Taiwan, beginning in 2013, the 13-valent pneumococcal conjugate vaccine (PCV13) was provided free of charge to children 2–5 years of age. In 2014, this was extended to children 1–5 years old. During 2012–2014, 953 cases of culture-confirmed pneumococcal disease (CCPD), including 104 invasive pneumococcal disease (IPD), were prospectively identified and analyzed at a 3,700-bed hospital in Taiwan. From 2012 to 2014, the incidence per 10,000 admissions decreased from 26.7 to 20.4 for CCPD (P < 0.001) and from 3.2 to 1.9 for IPD (P < 0.05). Significant reduction of PCV13 serotypes was firstly noted in children in 2013 and extended to both paediatric and adult populations in 2014. Simultaneously, the incidence per 10,000 admissions of non-PCV13 serotypes increased from 6.1 in 2012 to 9.3 in 2014 (P < 0.005). The most prevalent non-PCV13 serotypes were 15A, 15B, and 23A, each containing a predominant clone, ST63^15A, ST83^15B, and ST338^23A. From 2012 to 2014, isolates with penicillin minimum inhibitory concentrations >2 mg/L decreased from 27.8% to 8.1% (P < 0.001) among all isolates. PCV13 immunization in young children demonstrated an early protective effect in all ages. However, in the elderly, the effect was compromised by an emergence of non-PCV13 serotypes.

Differential impact of pneumococcal conjugate vaccines on bacteremic pneumonia versus other invasive pneumococcal disease

BACKGROUND

Bacteremic pneumonia (BP) accounts for ~35% of invasive pneumococcal disease (IPD) in young children. Our aims were to compare age, seasonal and serotype distribution of BP versus non-BP IPD and to determine whether the impact of the sequential 7/13-valent pneumococcal conjugate vaccine (PCV7/PCV13) introduction on disease incidence differed between BP and non-BP IPD in children <5 years of age.

METHODS

A nationwide, prospective, population-based, active surveillance (July 2004-June 2013) was conducted. All IPD episodes were included. PCV7 was introduced to the Israeli National Immunization Plan in July 2009 and has been replaced by PCV13 since November 2010.

RESULTS

In all, 983 (36.8%) BP and 1687 (63.2%) non-BP IPD episodes were recorded. A higher proportion of BP than that of non-BP IPD episodes (42.0% vs. 20.7%; P < 0.001) occurred in children >24 months old. Seasonality differed between BP and non-BP IPD, with yearly earlier peaks of non-BP IPD. The proportion of the 5 additional PCV13 serotypes (1, 3, 5, 7F and 19A) was higher in children with BP versus non-BP IPD (39.6% vs. 23.6%; P < 0.01). Shortly after PCV7 introduction, non-BP IPD rate was significantly reduced but that of BP was not. However, PCV13 introduction resulted in rapid reduction of BP rate, with a further reduction of non-BP IPD.

CONCLUSION

The differences in age distribution, seasonality and serotype distribution between BP and non-BP IPD suggest that the pathogenesis of these 2 entities is not identical and resulted in different impact rate dynamics after PCV7 and PCV13 introduction.

Emergence of serogroup 15 Streptococcus pneumoniae of diverse genetic backgrounds following the introduction of pneumococcal conjugate vaccines in Hong Kong

Serogroup 15 pneumococcal isolates from nasopharyngeal carriage of hospitalized children admitted to a teaching hospital in Hong Kong from April 2009 to September 2013 were characterized by pulse-field gel electrophoresis (PFGE), multilocus sequence typing, and antimicrobial non-susceptibility testing. The overall proportion of serogroup 15 isolates in the pre-PCV7 and post-PCV13 periods rose from 5.7% to 20.0%. The increase in trend for serotype 15B/C was statistically significant among children presented with pneumonia; bronchiolitis; upper respiratory tract infection; and febrile, non-respiratory diseases and for serotype 15A/F, among children with bronchiolitis and febrile, non-respiratory diseases. The predominant PFGE cluster of serotype 15B/C belonged to sequence type (ST) 199. Replacement of this more susceptible cluster (Ery and Tet non-susceptibilities of 32.2% and 25.4%) with the non-susceptible cluster, ST8859 (Ery and Tet non-susceptibilities of 91.7% and 87.5%) was noted. ST63 was the predominant serotype 15A cluster (Ery and Tet non-susceptibilities of 97.4% and 92.3%). Serogroup 15 subtypes have emerged in the post-PCV13 era, and these non-susceptible clusters warrant closer monitoring as candidates for incorporation to future pneumococcal vaccines.

Clinical characteristics and outcomes of patients with pleural infections due to Stenotrophomonas maltophilia at a medical center in Taiwan, 2004-2012

Stenotrophomonas maltophilia can cause various clinical diseases; however, pleural infections due to S. maltophilia are rare. We evaluated the clinical characteristics and outcomes of patients with pleural infections (complicated parapneumonic effusion or empyema) due to S. maltophilia who were treated at a medical center in Taiwan from 2004 to 2012. During the study period, 40 patients were treated for pleural infections due to S. maltophilia. The incidence of S. maltophilia pleural infections ranged from 2.66 per 1,000,000 patient-days in 2009 to 12.44 per 1,000,000 patient-days in 2011. Most of the patients with S. maltophilia pleural infections were immunocompromised male adults and all of the infections were acquired in healthcare settings. The majority of patients had polymicrobial pleural infections (n = 31, 77.5 %) and the most common pathogen was Pseudomonas aeruginosa (n = 12). The causes of pleural infections due to S. maltophilia were pneumonia due to S. maltophilia in two patients (5 %), post-surgical/tube thoracostomy in 26 (65 %) patients, and fistula (bronchopleural, esophagopleural and biliopleural) in 12 (30 %) patients. The 14-day and 30-day mortality rates were 32.5 % and 42.5 %, respectively. Pleural infections due to S. maltophilia are most commonly the result of surgical procedures, thoracostomy, and underlying fistulas. These infections are associated with a high mortality rate, especially among immunocompromised patients.