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.

Non-typeable Streptococcus pneumoniae infection in a medical center in Taiwan after wide use of pneumococcal conjugate vaccine

BackgroundStreptococcus pneumoniae is one of the most common pathogens to cause mucosal and invasive infection in humans. Most of the infection could be prevented through immunization by vaccines containing capsular polysaccharides but some infection may be caused by unencapsulated strains.MethodsClinical isolates of S. pneumoniae from January 2012 to December 2015 at Chang Gung Memorial Hospital, Taiwan. Serotyping by PCR method was performed. Clinical and laboratory information of patients infected by non-typeable pneumococci (NTP) were collected and analyzed.ResultsDuring the study period, 39 NTP isolates were identified. Most (21 of 39, 53.9%) were collected from purulent upper respiratory tract secretion. Others were from corneal abscess, sputum, and one from blood of a newborn. We recorded a 3.6-fold increase in the rate of isolation from 1.4% in 2012 to 5.0% in 2015 (p = 0.063). Co-infection was found in 24 cases; the major co-infecting pathogens included non-typeable Hemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. Most (39 of 40, 97.5%) of the isolates were susceptible to both penicillin and ceftriaxone. The dominant sequence type ST1106 and an emerging sequence type ST7502 were recognized.ConclusionsA gradual increase of NTP infection was found in northern Taiwan in the pneumococcal conjugate vaccine era. Non-typeable pneumococci can cause respiratory and ophthalmological mucosal infection. Invasive infection can occur in newborns or young infants. Most of the isolates remained susceptible to penicillin and ceftriaxone.     

Divergent serotype distribution between children with otitis media and those without in the pneumococcal conjugate vaccine era

We investigated pneumococcal carriage between children ≦5 years old with otitis media (OM) and those without. Non-PCV13 serotypes were common in both groups; 19A remained the second most common serotype among children with OM despite high PCV13 coverage. This is important when considering a schedule with reduced vaccine doses or reduced valency, and the modification of pneumococcal immunization schedule should be followed up closely to monitor the result of protection against pneumococcal infections.     

Antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in Ireland

Between January 1999 and June 2002, 646 invasive isolates of Streptococcus pneumoniae were collected in Ireland. MICs of penicillin, ciprofloxacin, cefotaxime, moxifloxacin and linezolid were determined by Etest methodology. Eighty-seven (13.5%) isolates showed intermediate resistance to penicillin, while seven (1.1%) showed high-level resistance. Eighty-seven (13.5%) isolates were resistant to erythromycin, but all isolates were susceptible to cefotaxime, moxifloxacin and linezolid. The prevalence of pneumococcal isolates non-susceptible to penicillin in Ireland is worryingly high, but currently there are alternative agents available to treat invasive infection.     

Nasopharyngeal carriage rate,serotype distribution,and antimicrobial susceptibility profile of Streptococcus pneumoniae isolated from children under five years old in Kotabaru,South Kalimantan,Indonesia

BackgroundStreptococcus pneumoniae is a bacterial pathogen that colonizes the human nasopharynx. Colonization is frequently reported to be high in young children. In this study, we investigated the nasopharyngeal (NP) carriage rate, serotype distribution, and antibiotic susceptibility of S. pneumoniae in children under five years of age in Kotabaru, South Kalimantan, Indonesia.MethodsNP swab specimens were collected from 399 young children (mean age: 30 months) who participated in the Rampa Village Community Health Center, with 74% of the participants being Bajau children. S. pneumoniae was identified using optochin susceptibility and bile solubility tests. Serotyping was performed by sequential multiplex PCR, and antimicrobial susceptibility profiling was performed by disk diffusion and microdilution methods.ResultsThe NP carriage rate of S. pneumoniae was 45% (180/399). The most commonly serotypes were 6A/6B (18%), followed by 15B/15C (17%), 19F (16%), 34 (8%), and 23F (5%); 46% of them were identified as strains of the PCV13 vaccine type. Additionally, almost half of the pneumococcal isolates were non-susceptible to penicillin (40%), whereas non-susceptibility to tetracycline (36.8%), trimethoprim/sulfamethoxazole (29.7%), erythromycin (16.8%), chloramphenicol (9.7%), and clindamycin (8.6%) was also found. We identified 18% (n = 34) of S. pneumoniae isolates as multidrug-resistant (MDR) strains, and serotype 19F was the most common (74%) among them.ConclusionsMDR S. pneumoniae vaccine type strains were dominated by serotype 19F. The implementation of a pneumococcal conjugate vaccine program in Indonesia might reduce MDR strains circulating in the community in the future.     

Microbiological and clinical characteristics of Streptococcus pneumoniae serotype 3 infection and risk factors for severe outcome: A multicenter observational study

Background/purposeSerotype 3 has persisted to be an important cause of invasive pneumococcal disease in adults in the post-vaccine era. We aimed to investigate clinical and microbiological characteristics of Streptococcus pneumoniae serotype 3 infection in Taiwan and identify the risk factors associated with severe clinical outcome.MethodsA multicenter observational study was conducted to analyze serotype 3 isolates collected between 2012 and 2021. Demographics, comorbidities, and risk categories were statistically compared with clinical outcome. Antimicrobial susceptibility testing and multilocus sequence typing were performed.ResultsA total of 146 isolates were collected, including 12 isolates regarded as colonizers. Among 134 infected cases, 54 (40.3%) were aged 65 and older. Mortality was significantly associated with diabetes mellitus, immunosuppression, immunodeficiency, high-risk status, and older age. Susceptibility rates were high to levofloxacin (98.9%), moxifloxacin (100%), vancomycin (100%), and ceftriaxone (97.3%). 25.3% (37/146) of the isolates showed intermediate susceptibility and 0.7% (1/146) showed resistance to penicillin. ST180 was the dominant sequence type. ST13 and ST9625 isolates were less susceptible to penicillin and ceftriaxone.ConclusionsSerotype 3 infection showed a high mortality rate, especially in patients with older ages and comorbidities. Although the incidence rates decreased during the COVID-19 pandemic, serotype 3 remained as an important cause of infection after the implementation of PCV13. Developing a more effective vaccine against serotype 3 and monitoring the antimicrobial-resistant sequence types are necessary.     

Changes in serotype distribution and antibiotic resistance of nasopharyngeal isolates of Streptococcus pneumoniae from children in Korea, after optional use of the 7-valent conjugate vaccine

We investigated serotype distribution and antimicrobial resistance of pneumococcal carriage isolates from children after optional immunization with the 7-valent pneumococcal conjugate vaccine (PCV7) in Korea. From June 2009 to June 2010, 205 (16.5%) pneumococcal isolates were obtained from 1,243 nasopharyngeal aspirates of infants and children at Seoul National University Children's Hospital, Korea. Serotype was determined by Quellung reaction and antibiotic susceptibility was tested by E-test. The results were compared to previous studies done in the pre-PCV7 period. In this study, the most common serotypes were 6A (15.3%), 19A (14.7%), 19F (10.2%), 35B (7.3%), and 6D (5.6%). The proportion of PCV7 serotypes decreased from 61.9% to 23.8% (P < 0.001). The overall penicillin nonsusceptibility rate increased from 83.5% to 95.4% (P = 0.001). This study demonstrates the impact of optional PCV7 vaccination in Korea; the proportion of all PCV7 serotypes except 19F decreased while antimicrobial resistant serotypes 6A and 19A further increased.     

Antimicrobial susceptibility and serogroup/serotype distribution of nasopharyngeal isolates of Streptococcus pneumoniae in healthy Estonian children in 1999–2003

This study determined nasopharyngeal (NP) carriage rates of Streptococcus pneumoniae among healthy Estonian children, aged 1-7 years, and characterised the serotype/serogroup distribution and antibiotic susceptibility rates. NP swabs were collected from 685 previously healthy children attending 29 day care centres during the winters of 1999-2000 and 2003. The NP carriage rate of S. pneumoniae was 44%. Rates of penicillin and erythromycin non-susceptibility were low (both 6%), but high (67%) rates of co-trimoxazole resistance were found. Among the pneumococcal serotypes identified, 64% were included in or cross-reacted with the licensed heptavalent pneumococcal vaccine.     

Emergence of a serotype 1 Streptococcus pneumoniae lineage colonising healthy children in Portugal in the seven-valent conjugate vaccination era.

Serotype 1 pneumococci are rarely isolated from carriers, but are an important cause of pneumococcal invasive disease in many regions of the world. This report describes the emergence and expansion of a single serotype 1 lineage (characterised by multilocus sequence type 306) among healthy carriers attending day-care centres in Portugal. The prevalence of serotype 1 strains among all pneumococci increased from 0% in 2001 and 2002, to 0.4% in 2003, and 3.1% in 2006. These observations paralleled the introduction and increased use of the seven-valent pneumococcal conjugate vaccine in the study group, suggesting a direct relationship between these events.     

Clonal structure and 21-year evolution of Streptococcus pneumoniae serotype 1 isolates in northern Spain

This study of 135 serotype 1 pneumococcal isolates (88 invasive and 47 non-invasive), collected between 1987 and 2007, gave eight sequence types (217, 227, 228, 304, 305, 306, 3860 and 3861) that group, using eBurst, into three different lineages and one singleton. The annual incidence of serotype 1 invasive episodes per million inhabitants increased from 1.8 in 1987–1993 to 4.0 in 1994–2000, and to 25.6 in 2001–2007. ST228 was the predominant clone until 1998. ST306 first appeared in 1998 and became the most prevalent sequence type (>80%) after the introduction, in June 2001, of the heptavalent pneumococcal conjugate vaccine.     

Genotyping and serotyping of macrolide and multidrug resistant Streptococcus pneumoniae isolated from carrier children

Aims: Streptococcus pneumoniae, an opportunistic pathogen commonly carried asymptomatically in the nasopharynx of children, is associated with increasing rates of treatment failures due to a worldwide increase in drug resistance. We investigated the carriage of S. pneumoniae in children 5 years or younger, the identity of prevalent serotypes, the rates of resistance to macrolides and other antimicrobial agents and the genotypes responsible for macrolide resistance. Materials and Methods: Nasopharyngeal swabs were collected from 157 children under 5 years for cultural isolation of S. pneumoniae. Antibiogram of isolates was determined using the disk diffusion test, and the minimal inhibitory concentration to macrolides was determined using the E-test. Isolate serotypes and macrolide resistance genes, erm(B) and mef(E), were identified using multiplex polymerase chain reactions. Results: S. pneumoniae was recovered from 33.8% of children; 41.9% among males and 21.9% among females (P = 0.009). The highest carriage rate occurred among age groups 7–12 months and 49–60 months. Most frequent serotypes were 19F, 6A/B, 11A, 19A, 14 and 15B/C. Resistance to macrolides was 60.4%. Resistance to oxacillin, trimethoprim/ sulfamethoxazole and clindamycin was present among 90.6%, 54.7% and 32.1% of isolates, respectively. All isolates were susceptible to chloramphenicol, levofloxacin and vancomycin. Isolates resistant to one or more macrolide drugs were more likely to be multidrug resistant. Resistance to clindamycin or oxacillin coexisted with macrolide resistance. Among the erythromycin-resistant isolates, erm(B), mef(E) and erm(B) and mef(E) genes were present at rates of 43.8%, 37.5% and 6.3%, respectively. Erm(B) and mef(E) were associated with very high level and moderate-to-high level resistance to macrolides, respectively. Conclusion: A significant proportion of children harboured macrolide and multidrug-resistant S. pneumoniae.     

Antimicrobial susceptibility patterns of Haemophilus influenzae and Streptococcus pneumoniae isolates in a Beirut general university hospital between 2000 and 2004

Susceptibility patterns of Streptococcus pneumoniae and Haemophilus influenzae collected over a 5-year period in a Beirut general university hospital were studied. Only 40.6-50% of S. pneumoniae isolates were susceptible to penicillin G. Susceptibility to clindamycin and erythromycin decreased from 94.1% and 89.7%, respectively, in 2000 to 75% and 71.9%, respectively, in 2004. All isolates were susceptible to ceftriaxone, ciprofloxacin and vancomycin. For H. influenzae, no resistance was observed to amoxycillin-clavulanate, ceftriaxone, ciprofloxacin and rifampicin, with >92% of isolates showing susceptibility to cefuroxime, chloramphenicol, erythromycin and tetracycline. The proportion of beta-lactamase-positive isolates varied between 22.7 and 30.8%.     

A novel genetic variant of Streptococcus pneumoniae serotype 11A discovered in Fiji

ObjectivesAs part of annual cross-sectional Streptococcus pneumoniae carriage surveys in Fiji (2012–2015), we detected pneumococci in over 100 nasopharyngeal swabs that serotyped as ‘11F-like’ by microarray. We examined the genetic basis of this divergence in the 11F-like capsular polysaccharide (cps) locus compared to the reference 11F cps sequence. The impact of this diversity on capsule phenotype, and serotype results using genetic and serologic methods were determined.MethodsGenomic DNA from representative 11F-like S. pneumoniae isolates obtained from the nasopharynx of Fijian children was extracted and subject to whole genome sequencing. Genetic and phylogenetic analyses were used to identify genetic changes in the cps locus. Capsular phenotypes were evaluated using the Quellung reaction and latex agglutination.ResultsCompared to published 11F sequences, the wcwC and wcrL genes of the 11F-like cps locus are phylogenetically divergent, and the gct gene contains a single nucleotide insertion within a homopolymeric region. These changes within the DNA sequence of the 11F-like cps locus have modified the antigenic properties of the capsule, such that 11F-like isolates serotype as 11A by Quellung reaction and latex agglutination.ConclusionsThis study demonstrates the ability of molecular serotyping by microarray to identify genetic variants of S. pneumoniae and highlights the potential for discrepant results between phenotypic and genotypic serotyping methods. We propose that 11F-like isolates are not a new serotype but rather are a novel genetic variant of serotype 11A. These findings have implications for invasive pneumococcal disease surveillance as well as studies investigating vaccine impact.     

Adult invasive pneumococcal disease between 2003 and 2006 in North-Rhine Westphalia, Germany: serotype distribution before recommendation for general pneumococcal conjugate vaccination for children <2 years of age

A laboratory-based surveillance study of adult invasive pneumococcal disease was conducted in North-Rhine Westphalia, Germany's most populous federal state, with approximately 18 million inhabitants. Invasive isolates ( n  = 519) were obtained between 2003 and 2006, before the general recommendation for vaccination of German children <2 years with the pneumococcal conjugate vaccine was issued at the end of July 2006. Penicillin G resistance was observed in 5% of meningitis cases. In the non-meningitis group, only intermediately resistant strains were detected (0.4%). Intermediate resistance to cefotaxime occurred both in meningitis cases (1.7%) and non-meningitis cases (0.4%). Non-susceptibility rates (intermediate resistance and resistance) were 16.2% for macrolides, 10.9% for trimethoprim–sulphamethoxazole, 5.0% for tetracycline, 3.9% for clindamycin, and 0.4% for levofloxacin. All isolates were susceptible to amoxycillin (non-meningitis) and telithromycin. The leading serotypes were serotypes 14 (14.3%), 7F (9.4%), 3 (9.2%), 4 (8.7%) and 1 (8.1%). Serotype coverage for the seven-valent conjugate vaccine was 43.9%. For the ten-valent and 13-valent vaccines (in development), the coverages were 61.8% and 76.7%, respectively. The 23-valent polysaccharide vaccine had a coverage of 91.1%.     

北京上海广州深圳4家儿童医院肺炎住院患儿肺炎链球菌分离株的血清型分布

目的了解目前从中国住院治疗肺炎患儿分离到的肺炎链球菌的血清型分布,及几种蛋白多糖结合疫苗的覆盖率,评估应用蛋白多糖结合疫苗预防肺炎链球菌感染的价值。方法选择2006年2月16日至2007年2月16日在首都医科大学附属北京儿童医院、复旦大学附属儿科医院、广州市儿童医院和深圳市儿童医院呼吸科住院治疗的肺炎患儿为研究对象,采用一次性吸痰管收集全部病例的呼吸道分泌物标本分离肺炎链球菌,部分患儿进行脑脊液、血液和胸腔积液中肺炎链球菌的分离。采用荚膜肿胀实验进行血清型分析。对4家儿童医院肺炎链球菌分离率和血清型进行分析,率的比较采用χ2检验或Fisher精确概率法。结果研究期间共纳入2865例肺炎患儿,2865例呼吸道吸取物标本中分离到肺炎链球菌279株,其中有2株不同血清型菌株分离自同一病例,分离阳性率为9.7%（278/2865）。3/8例胸腔积液中分离到肺炎链球菌,其中2例同时从呼吸道分泌物分离到肺炎链球菌,取其一进行血清分型,另1株从胸腔积液中分离的肺炎链球菌复苏失败,未进行血清分型。脑脊液和血液标本中未分离到肺炎链球菌。共有279株肺炎链球菌进行了血清型分析,以19F型最常见（60.6%,169/279）,其次为19A（9.7%,27/279）、23F（9.3%,26/279）和6B（5.4%,15/279）,上述4种血清型占全部菌株的84.9%（237/279）。肺炎链球菌7价结合疫苗（PCV7）覆盖率为81.0%,但在北京仅为46.0%,明显低于上海（80.0%）、广州（98.4%）和深圳（94.4%）。9价、10价和11价疫苗的覆盖率与PCV7相比并没有明显增加。13价疫苗的覆盖率（92.8%）较PCV7明显升高。结论4家儿童医院肺炎住院患儿分离的肺炎链球菌以19F、19A、23F和6B型常见。PCV7覆盖率为87%。     

79株肺炎链球菌的耐药性测定

目的调查北京地区肺炎链球菌对青霉素等抗生素的耐药率。方法用Ｅｔｅｓｔ及琼脂稀释法测定临床分离的７９株肺炎链球菌１５种抗生素的最低抑制浓度（ＭＩＣ）。结果Ｅｔｅｓｔ测得１０株（１２．７％）低耐青霉素（ＭＩＣ０．１２５～１μｇ／ｍｌ），１株（１．３％）高耐青霉素（ＭＩＣ４μｇ／ｍｌ）；仅１株处于头孢曲松、头孢噻肟中介范围（ＭＩＣ１μｇ／ｍｌ）．琼脂稀释法测得阿莫西林、阿莫西林／棒酸、头孢呋肟、环丙沙星、氯霉素、四环素、红霉素的耐药率分别为１．３％、１．３％、２．５％、２．５％、１６．５％、４９．４％、４０．５％，所有菌株对头孢曲松、万古霉素敏感。结论北京地区１４％的肺炎链球菌耐青霉素，耐三代头孢菌素及多重耐药株罕见。     

Changes in Streptococcus pneumoniae serotypes causing invasive disease with non-universal vaccination coverage of the seven-valent conjugate vaccine

The pneumococcal seven-valent conjugate vaccine (PCV7) has been administered in Portugal since late 2001 through the private sector. To evaluate the impact of PCV7 use, the serotypes and antimicrobial susceptibility of pneumococci causing invasive disease in Portugal during 2003–2005 were determined and compared with available data for the period 1999–2002. Changes in serotype distribution compatible with the introduction of PCV7 were shown for children ≤5 years of age from 2003 onwards and for adults from 2004 onwards. PCV7 use with coverage of 43% of children with four doses in the 2004 birth cohort, although substantially below universal coverage, seems to have contributed to greatly reducing the proportion of invasive infections due to vaccine serotypes  4, 6B, 14 and 23F. Similarly, significant indirect effects on the serotype distribution of pneumococci causing infections in adults were noted, with reductions in the proportion of invasive infections caused by serotypes  4, 5 and 14. These changes were accompanied by an increase in the proportion of two non-vaccine serotypes: 19A isolates in all age groups and 7F isolates in adults. Whereas serotypes  6B, 14 and 19A were associated with multidrug resistance, isolates expressing serotypes  4 and 7F were fully susceptible for the most part. There were no changes in the proportion of resistant isolates within each serotype and, in spite of the changes in serotype prevalence, there was not an overall reduction in the proportion of infections caused by resistant pneumococci.     

Evaluation of the WIDER I system for antimicrobial susceptibility testing of clinical isolates of Haemophilus influenzae and Streptococcus pneumoniae

The aim of this study was to evaluate the WIDER I system for susceptibility testing of Haemophilus influenzae and Streptococcus pneumoniae . MICs of 12 antimicrobials against 42 H. influenzae and 58 S. pneumoniae strains were determined using 1W MIC panels and compared with those obtained by microdilution. Overall essential agreements were >99%. Very major errors were not detected. Major errors occurred with ampicillin (1.7% H. influenzae ). Minor errors were 2.3% (amoxicillin–clavulanate, cefuroxime, chloramphenicol), 7.1% (ampicillin) and 16.7% (clarithromycin) for H. influenzae , and 1.7% (chloramphenicol, erythromycin, meropenem), 3.4% (amoxicillin–clavulanate, cefuroxime, tetracycline) and 8.6% (levofloxacin) for S. pneumoniae . The WIDER I system is a reliable method for susceptibility testing of H. influenzae and S. pneumoniae .